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This application is the national phase under 35 U.S.C. §371 of PCT International Application No. PCT/HU97/00073 which has an International filing date of Nov. 12, 1997 which designated the United States of America.
SUMMARY OF THE INVENTION
This invention relates to the process of preparation of mixed ethers of general formula I, wherein
Ar represents an alicyclic, aromatic or one or more heteroatom-containing heterocyclic moiety, optionally substituted by one or more C 1-4 alkoxy, methylenedioxy, C 1-4 alkyl halogen, C 1-4 haloalkyl or nitro-group, and/or condensed with a benzene ring,
R 1 and R 2 independently mean hydrogen, C 1-4 alkyl, C 1-4 haloalkyl, C 2-4 alkenyl, phenyl, substituted phenyl, C 3-6 cycloalkyl group,
R 3 means C 3-6 alkynyl group, optionally substituted by one or more C 1-6 alkyl, C 3-6 alkenyl, C 3-6 alkynyl, C 1-6 haloalkyl group, or halogen atom; or a C 1-4 alkyloxy-C 1-4 alkyl-oxy-C 1-4 alkyl group,
under acidic conditions, by the reaction of compounds of general formula II, wherein
X means hydroxy, halogen or sulfonester leaving group, with compounds of general formula III , wherein
R 3 has the same meaning as above.
In the term Ar the aromatic group is favourably phenyl or naphthyl group, Ar as a heterocyclic moiety may contain one or more O, S, N heteroatoms, it may favourably represent benzodioxole-, benzodioxane-, 2-benzofuran-, 7-benzofuran-moieties.
The alicyclic group may favourably be condensed with a benzene ring, thus for instance may represent indane group, or 1,2,3,4-tetrahydronaphthyl group. The carboximide group may favourably represent phthalimide moiety. The aromatic, heterocyclic and alicyclic Ar groups are optionally substituted by C 1-4 alkoxy-, methylenedioxy-, C 1-4 alkyl-, halogen-, C 1-4 haloalkyl- or nitro group.
FIELD OF THE INVENTION
The ethers of general formula I are potential starting materials or active ingredients of a number of chemical products. Several representatives of them are arthropodicide synergists of outstanding activity (Hungarian patent application No 3318/95). With the exception of the methylenedioxy (MDP) synergists having saturated side-chain (such as PBO, i.e. 5-[2-(2-butoxyethoxy)ethoxymethyl]-6-propyl-1,3-benzodioxol), which have been known, the compounds are new, irrespective of their simple structures. Owing to their outstanding significance, their preparation and economical synthesis is of great importance.
BACKGROUND OF THE INVENTION
The above ethers can be prepared by the general methods known for the synthesis of ethers (Gy. Matolesy, M. Nádasdy, V. Andriska; Pesticide Chemistry , Akadémia (1988); Hungarian patent specifications No 3318/95). The essence of these methods is to react the alkali salt of the alcohol component with the partner, according to the rules of the nucleophilic substitution. The partner contains a leaving group, which is usually a halogen, preferably bromo atom. The reaction may be accomplished in two ways, depending on which part of the molecule is the nucleophilic partner. Due to the greater reactivity of benzyl halogenides, in the practice usually the alcoholate of the side-chain is reacted with benzyl bromide. This method is, however, limited when the alcoholate is for some reason hard to prepare. In these cases the inverse method may bring solution, but usually poorer reactions can be expected. This sort of ether preparation is known in the organic chemistry as the classical Williamson synthesis (B. P Mundy, M. G. Ellerd, Name Reactions and Reagents in Organic Synthesis , Wiley (1988)).
The reaction has, however, several drawbacks. The formation of the alcoholate is costly for the industry, it requires expensive reagents and refined technology with guaranteed water-free conditions or with a drying step (Hungarian patent applications No. 180500, 190842).
The preparation of the halogenide or of the partner containing the leaving group requires a separate step and the use of further costly reagents. In case the alpha carbon atom contains additional substituents (R 1 and/or R 2 is different from hydrogen) the preparation of the activated, for example halogen derivative involves difficulties as the product is susceptible to elimination reaction or side reactions, for instance aromatic electrophilic substitution. The yield of the coupling strongly depends on the reactivity of the partner and the resulting product needs further purification.
For the preparation of ethers in general, further methods are also known. The oldest and most well-known among them is the acid catalyzed dimerisation of alcohols (Houben Weyl 6/3 11-19). According to the literature the reaction usually requires high temperature and to avoid decomposition the product has to be continuously removed from the reaction mixture. The oxonium cation formed on the action of the acid may easily take part in rearrangement reactions or it may be stabilized by the so called β-elimination of the hydrogen atom from the neighbouring carbon atom, giving rise to the appropriate olefine. This causes the formation of considerable amount of decomposition products, complicated by the fact that the water which is formed in the reaction slows down the process. As a consequence, the performance of the reaction (yield, purity) is low. It is understandable therefore, that this method is not counted for when a synthesis is planned. It is rather taken into consideration as a side-reaction of acid-catalyzed processes ( Chem. Pharm. Bull . 31, 3024, (1983)).
In the case of the dibenzyl ethers, to eliminate the draw-backs, the methyl sulfoxide-induced dimerization method has been worked out ( J. Org. Chem . 42, 2012, (1977)). Owing to the applied reagent and high temperature (175° C.), however, the method can not be utilized in industrial scale.
It was a major break-through when it was revealed that, in addition to the fact that the ether formation can be catalyzed by Lewis acids, the reaction with zinc(II) chloride in dichloroethane can be performed under relatively mild conditions ( J. Org. Chem . 52, 3917, (1987)). The method, however, has been worked out practically only for dimerization and intramolecular cyclization reactions. For mixed ethers the reproducibility of the reaction, as well as the quality and yield of the product are poor. With benzyl(p-methoxybenzyl)alcohol, containing an aromatic substituent, the reaction proceeds in low yield due to polymerization; the mixed ether with unsaturated chain (α-methylbenzyl allyl ether)—unlike its saturated analogue—can be obtained again, only in poor yield, because of dimerization. In a published version of the reaction the benzyl halogenide was reacted with the nucleophilic reagent in the presence of zinc oxide ( Tetrahedron , 38, 1843, (1982)), but applicability of this reaction for the compounds of general formula I is not known.
The acid-catalyzed ether formation takes place through the appropriate cationic intermediate. Stability of ring-substituted 1-phenylethyl carbocations and their reaction with nucleophilic reagents in trifluoroethanol/water=1./I model system has been studied ( J. Am. Chem. Soc ., 106, 1361, ((1984); 106, 1373, (1984). The two references, however do not give examples on the preparation of compounds of general formula I., and do not give a hint concerning their synthesis respect to the reaction media (polarity, solvation), which—as shown by the two references—play major role in the reaction and even small modifications may disturb the sensible equilibria. Authors of the above two references in their later theoretical work have published that ethers, similar type to general formula I., are surprisingly sensible to acids, differing from other ethers. Ether formation proceeds in a reversible reaction, which increases the possibility of by-product formation, deteriorating purity and yield of the product. As shown by the data published, alkoxyalcohols, such as ethylene glycol monomethyl ether, have poor reactivity, unsaturated alcohols e,g. propargyl alcohol have medium reactivity, falling well behind the reactivity of simple saturated alcohol like methanol, ethanol and butanol, which react readily. Electron-withdrawing substituents of the aromatic ring enhance, electron-donating substituent decrease the equilibrium constant of the ether formation. Increasing the water/trifluoroethanol ratio causes unfavourable effect on the direct ether formation.
The production of the ethers is an extremely difficult task for the industry. Not only because of expensive reagents and possible side reactions, but also because both the starting alcohols and the resulting ethers easily form peroxides and are potential explosives. In addition, the alkenyl compounds, due to the triple bond, are sensible to heat. At a large scale (1000 t/year) safe production is only conceivable if the reaction can be carried out under mild conditions and the end-product, which is in most cases a liquid, does not have to be further purified, distilled.
BRIEF DESCRIPTION OF THE DRAWING
The drawing shows general formulae I, II, and III that represent aspects of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the light of the above we investigated in details the possibilities of the preparation of asymmetric ethers of general formula I. The essence of our method which we worked out on the basis of our experimental results, is that the mixed ethers of general formula I., wherein the meaning of the substituents is the same as described above, can very favourably prepared by reacting the compounds of general formula II., wherein X means hydroxy, halogen or sulfonester leaving group, with 1-3 molar equivalent of the alcohol of general formula III., wherein the meaning of the substituents is the same as above, in the presence of an acid, Lewis acid, metal oxide or metal carbonate. The resulting ether of general formula I. is isolated, the excess of the alcohol is recovered, if desired, the product is stabilized by the addition of a base and/or an anti-oxidant. In general formulae I., II. and III. the meanings of Ar, R 1 , R 2 and R 3 are the same as given above.
As for acids favourably 0.01-3 molar equivalent of a strong mineral or organic acid, preferably hydrochloric acid, sulfuric acid, perchloric acid or aromatic sulfonic acid is applied. The reaction is carried out in the solution of salts, preferably in the solution of sodium chloride, calcium chloride, magnesium chloride, zinc chloride, preferably in, a 10 w/w % aqueous solution of the acid, preferably saturated with the inorganic salt, and at a temperature of (−20)-(+30)° C.
As for Lewis acid preferably 0.01-3 molar equivalent of zinc(II) chloride or an aromatic sulfonic acid, preferable benzenesulfonic acid or para-toluenesulfonic acid is applied and the reaction is carried out in an apolar aprotic solvent, at a temperature of (−30)-(+40)° C.
As for metal oxide preferably 0.01-3 molar equivalent of zinc oxide, as for metal carbonate zinc carbonate is applied and the reaction is carried out without solvent or in the presence of an apolar aprotic solvent.
As for organic solvents, halogenated solvents proved to be good, among them dichloroethane was the best. In that case Lewis acid can also be used. Zinc(II) chloride, as reported in the literature, did not prove well for the preparation of structures very similar to compounds of general formula I., it resulted low yields and contaminated products (J. Org. Chem. 52, 3917, (1987)), nevertheless, in the optimized system of our invention the reaction proceeded in good yield and resulted the product with appropriate purity. Similarly, the reaction also proceeded well when using zinc oxide. The zinc halogenide by-product did not cause polimerization in that case, either. The reaction doesn't require anhydrous solvents and conditions. The water, which forms during the reaction, does not hinder the full accomplishment of the reaction, it bounds the catalyst. The resulting emulsion or suspension can be separated by simple precipitation or filtration, and following a work-up procedure it can be re-utilized.
In the industrial application the use of water as solvent is especially convenient. This version is unique not only because it has not been used earlier, but also because it is surprising, since the formation of ethers—an equilibrium reaction—was expected to be suppressed in aqueous medium. ( J. Am. Chem. Soc ., 107, 1340 (1985)). The method, in contrast to literature data, was very good applicable even for preparation of benzyl alkynyl ethers with electron-donating (hydroxy, methoxy, ethoxy, methylenedioxy group) substituents. Benzyl ethers containing phenolic hydroxy group can also be directly, selectively synthesized, despite of the fact that they contain more than one nucleophilic centre. Enhancing the polarity of the medium is favourable. Consequently, the use of auxiliary materials, preferably the use of various salts is favourable. Selecting the right parameters the reaction can be shifted towards the formation of the product. Of the acid catalytic amount, 1-2 mol % is sufficient. The reaction is fast even at low temperature, undesired side reactions can thus be avoided. The alcohol is preferably applied in excess amount, by this way reaction time may significantly be shortened. The product may be isolated from the reaction mixture by simple sedimentation and the electrolyte may be re-used. The starting alcohol recovered from the process may be re-used. The process is thus practically quantitative for both components. The raw product obtained in the reaction is of very good quality. Its purity achieves 93-95%. It may of course be further purified by distillation, or if possible, by crystallisation but it may be used straightaway. To enhance its stability and hinder its acidic hydrolysis it is suitable to wash the product to neutral and buffer it in the basic pH region. For the sake of safer handling the addition of anti-oxidants of various type is recommended.
As for anti-oxidants e.g. TMQ; BHT; hydroquinone; hydroquinone monomethyl ether; 2,2,6,6-tetramethyl-4-piperidinol-N-oxide may preferably be used.
To demonstrate our process we give the following non limiting examples without the intention of being complete.
EXAMPLES
1.) 1-[1-(But-2-ynyloxy)ethyl]-3-hydroxy-4-methoxybenzene
A.)
1.7 g (10.7 mmol) of 1-(3-hydroxy-4-methoxyphenyl)ethanol is dissolved in 1.4 g of 2-butynol, and to that solution 1.5 ml of 1% HCl-50% CaCl 2 solution was added under stirring at room temperature. The mixture was stirred at that temperature overnight. The reaction was followed by TLC. (eluent: n-hexane-ethyl acetate 7:3; R f =0.19). to the reaction mixture diethyl ether was added, until the oily organic phase dissolved. The mixture was then neutralized with 1M NaOH solution, the two phases were separated, the aqueous layer as twice extracted with ether, the combined or layers were washed subsequently with water and saturated sodium chloride solution, dried over MgSO 4 , filtered and evaporated.
Yield: 2.08 g (94%) colourless, thick oil. GC (CP 9000, CP-SIL-5CB 60 m×0.53 mm, 5 ml/min N 2 FID, 250° C.): t R =4.44 min, >93%. IR (CHCl 3 , cm −1 ) υ: 3601, 3541, 2972, 2924, 2857, 1728, 1615, 1596, 1507, 1457, 1443, 1372, 1308, 1288, 1271, 1235, 1164, 1132, 1110, 1084, 1043, 1030, 1004, 934, 877, 841, 808, 644, 611. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.44 (3H, d, J=6.4 Hz, CH—CH 3 ), 1.84 (3H, t, J=2.2 Hz≡C—CH 3 ), 3.81 and 4.01 (2H, ABX 3 , J AB =15.0 Hz, J AX =J BX =2.34 Hz, ≡C—CH 2 O), 3.87 (3H, s, OCH 3 ), 4.52 (2H, q, J=6.4 Hz, Ar—CHO), 5.80 (1H, OH), 6.82 (2H, d, J=1.12 Hz aromatic 5,6-CH) 6.91 (1H, t, aromatic-CH). 13 C-NMR (50 MHz, CDCl 3 ) δ: 3.56 (≡C—CH 3 ), 23.65 (CH—CH 3 ), 55.84 (OCH 3 ), 55.89 (≡C—CH 2 O), 75.35 (≡C—CH 2 ), 76.06 (Ar—CH—CH 3 ), 81.89 (≡C—CH 3 ), 110.47 (C-2), 112.66 (C-5), 118.08 (C-6), 135.93 (C-1), 145.65 (C-4), 146.08 (C-3).
B.)
The procedure is described in the previous example is followed, with the difference that instead of calcium chloride solution zinc(II) chloride solution is applied. The resulting product is identical with the product obtained in the previous process.
2.) 1-[1-(But-2-ynyloxy)ethel]-3,4-dimethoxybenzene/1-(3′,4′-dimethoxypheneyl)ethylbut-2-ynyl ether/
A.)
Preparations to the Process:
In 250 ml of water 125 g of calcium chloride dihydrate is dissolved under stirring. On the basis of its density (d=1.33 g/ml) this solution equals with an approx. 35 w/w % calcium chloride solution. If necessary, the solution is filtered. In a volumetric flask 7.6 ml (9.0 g) of conc. hydrochloric acid is diluted with the previous solution to 250 ml.
Procedure:
To the vigorously stirred mixture of 500.0 g α-methylveratryl alcohol and 192.3 g 2-butyn-1-ol are added a mixture consisting of 250 ml of the calcium chloride-hydrochloric acid solution and 192.3 g of 2-butyn-1-ol is added in a fast rate. The reaction is followed by GC and TLC analysis. After 6 hours the relative amount of the of the product is 92-93%, as shown by GC analysis whereas the amount of the starting material decreases to less than 2%. Following this the reaction mixture is diluted understirring with 500 ml of ether and it is neutralized under stirring with 1M sodium hydroxide solution. After separation the aqueous layer is extracted with 2×100 ml of ether. The combined organic phase is washed with saturated sodium chloride solution (the pH of the aqueous layer is checked for neutrality), and it is dried. The solution is evaporated under atmospheric pressure. The excess of the butynol is distilled off in water jet vacuo. The recovered 182 g of butynol may be used again following investigation of purity (GC, refractive index). Product: 650 g of colourless oil.
Purity: by direct integration 93%, with octacosane internal standard 95%, yield: 94%, n D 20 1720 1.5280. IR (CHCl 3 cm −1 ) ν: 2976, 2855, 2837, 1605, 1595, 1514, 1465, 1419, 1371, 1353, 1311, 1260, 1164, 1141, 1086, 1027, 864. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.46 (3H, d, J=6.5 Hz, CH—CH 3 ), 1.85 (3 h, t, J=2.3 Hz, ≡C—CH 3 ), 3.83 and 4.01 (2H, ABX 3 , J AB =15.0 Hz, J AX =J BX =2.3 Hz, ≡C—CH 2 —O), 3.87 and 3.89 (altogether 6H, each s , O—CH 3 ), 4.55 (2H, q, J=6.5 Hz, Ar—CH—O), 6.80-6.89 (3H, m, aromatics). 13 C-NMR (50 MHz, CDCl 3 ) δ: 3.61, (≡C—CH 3 ), 23.76 (CH—CH 3 ), 55.87 (O—CH 3 ), 55.96 (≡C—CH 2 —O), 75.36 (≡C—CH 2 ), 76.40 (Ar—CH—O), 81.91 (≡C—CH 3 ), 109.06 (C-2), 110.86 (C-5), 118.94 (C-6), 135.30 (C-1), 148.52 (C-3), 149.19 (C-4).
B.)
To a flask equipped with magnetic stirrer, condenser, and drying tube filled with calcium chloride, α-methylveratryl alcohol (8.72 g, 0.0478 mol) and 2-butyn-1-ol (4.36 g, 0.0623 mol) are added, and then dissolved in 100 ml of dichloroethane. Under stirring at room temperature zinc(II) chloride (1.97 g, 0.0145 mol) is added to the mixture. The reaction is accompanied by a characteristic change of colour. After 2 hours of reaction the aqueous part formed in the reaction is separated, the organic phase is washed with 3×30 ml of saturated sodium chloride solution, dried and evaporated. The raw product (12.1 g) is distilled in vacuo with the help of a vacuum pump. Yield: 9.2 g (0.0393 mol, 82.2%). GC (with internal standard) 98.2%. The material is identical with the compound obtained by the previous method.
3.) 1-[1-(But-3-ynyloxy)ethyl]-3,4-dimethoxybenzene
Into a flask equipped with stirrer 3.0 g of (0.0164 mol) α-methylveratryl alcohol and 2.3 g (0.0329 mol) of 3-butyn-1-ol are added, and to the mixture 1.5 ml of the solution consisting of 50 w/v % of calcium chloride-1 w/w % hydrochloric acid is added at a fast rate. The mixture is stirred overnight at room temperature. It is then diluted with ether, and the mixture is neutralized with a few drops of 1 M sodium hydroxide solution. The two phases are separated, the aqueous phase is thoroughly extracted with ether. The combined organic layers are washed with saturated sodium chloride, dried and evaporated.
Yield: 3.5 ((93%) Purity 92%. IR (CHCl 3 , cm −1 ) υ: 3307, 3027, 2958, 2933, 2869, 2838, 2120, 1607, 1595, 1509, 1465, 1443, 1259, 1163, 1142, 1098, 1027, 861. 1 H-NMR (200 MHz. CDCl 3 ) δ: 1.45 (3H, d, J=6.5 Hz, CH—CH 3 ), 1.96 (1H, t, J=2.7 Hz, ≡CH), 2.44 (2H, td, J=7, 2.7 Hz, CH 2 —C≡), 3.43 (2H, t, J=7 Hz), 3.87 and 3.89 (altogether 6H, each s, OCH 3 ), 4.38 (2H, q, J=6.5 Hz, Ar—CHO), 6.83 (2H, d, aromatic), 6.90 (1H, s, aromatic). 13 C-NMR (50 MHz, CDCl 3 ) δ: 19.95 (OCH 2 —CH 2 ), 24.0 (CH—CH 3 ), 55.77 and 55.82 (OCH 3 ), 66.33 (OCH 2 —CH 2 ), 69.09 (≡CH), 77.87 (Ar—CH—CH 3 ), 81.43 (≡C—CH 2 ), 108.87 (C-2), 110.81 (C-5), 118.49 (C-6), 136.12 (C-1), 148.34 (C-3), 149.12 (C-4).
4.) 1-{1-[(Z)-3-chloro-but-2-envyloxy]ethyl}-3,4-dimethoxybenzene
Into a flask equipped with stirrer 4.27 g (0.02345 mol) α-methylveratryl alcohol and 5.0 g (0.0469 mol) 2-chlorobut-2-en-1-ol (consisting mainly of the Z geometric isomer) are placed, and to the mixture 5.0 ml of the 50 w/v % calcium chloride-1 w/w % hydrochloric acid solution is added, at a fast rate. The mixture is stirred overnight at room temperature. Then it is diluted with ether, and the mixture is neutralized with a few drops of 1 M sodium hydroxide solution. The two phases are separated, the aqueous phase is thoroughly extracted with ether. The combined organic layers are washed with saturated sodium chloride, dried and evaporated. 5.7 g colourless oil is obtained. Yield:90%. Purity (GC) approx. 88.5%. GC (CP 9000, CP-SIL-5CB, 60 m×0.53 mm, 5 ml/min N 2 , FID, 250° C.): IR (CHCl 3 , cm −1 ) υ: 2973, 2931, 2862, 2839, 1659, 1606, 1595, 1511, 1465, 1443, 1261, 1164, 1141, 1093, 1028. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.43 (3H, d, J=6.5 Hz, CH—CH 3 ), 1.97 (3H, J=0.5 Hz, ═CCl—CH 3 ), 3.80 (2H, m, OCH 2 ), 3.87 and 3.89 (altogether 6H , each s, OCH 3 ), 4.38 (2H, q, J=6.5 Hz, Ar—CHO), 5.78 (1 H, m, CH═CCl), 6.83 (2H, d, Ar), 6.87 (1H, d, Ar). 13 C-NMR (50 MHz, CDCl 3 ) δ: 21.23 (═CCl—CH 3 ), 24.08 (CH—CH 3 ), 55.84 (OCH 3 ), 64.10 (OCH 2 ), 77.05 (Ar—CHO), 108.92 (C-2), 110.91 (C-5), 118.74 (C-6), 124.43 (CH═CCl), 134.0 (CH═CCl), 135.89 (C-1), 148.49 and 149.23 (C-3 and C-4).
5.) 1-[1-(But-2-ynyloxyethyl]3-methoxy-4-hydroxybenzene
4.0 g (23.6 mmol) of 1-(3-methoxy-4-hydroxyphenyl)ethyl alcohol is dissolved in 4.0 g of 2-butynol and to the solution 8.0 ml of the 50 w/v % of calcium chloride-1 w/w % hydrochloric acid solution is added under stirring at room temperature. The mixture is stirred overnight at that temperature. The reaction is followed by TLC method (eluent: n-hexane—ethyl acetate 7:3, R f =0.55). To the mixture ether is added, until the oily organic phase dissolves and the reaction mixture is neutralized with 1 M sodium hydroxide solution. The two phases are separated, the aqueous phase is twice extracted with ether, the united organic phase is washed subsequently with water and saturated sodium chloride solution, dried over MgSO 4 , filtered and evaporated.
Yield 4.8 g (92.0%) thick oil. GC (CP 9000, CP-SIL-5CB 60 m×0.53 mm, 5ml/min N 2 FID, 250° C.): t R =4.3 min, >93%. IR (CDCl 3 , cm −1 ) υ: 3668, 3540, 2973, 2923, 2858, 2424, 2376, 2233, 1729, 1610, 1512, 1465, 1453, 1433, 1372, 1344, 1320, 1268, 1235, 1186, 1162, 1128, 1111, 1082, 1036, 1005, 970, 913, 886, 859, 822, 698, 645, 598. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.45 (3H, d, J=6.5 Hz, CH—CH 3 ), 1.84 (3H, t, J=2.2 Hz ≡C—CH 3 ), 3.82 and 4.01 (2H, ABX 3 , J AB =15.0 Hz, J AX =J BX =2.3 Hz, ≡C—CH 2 O), 3.88 (3H, s, OCH 3 ), 4.53 (2H, q, J=6.5 Hz, Ar—CHO), 6.76-6.89 (3H, m, aromatic). 13 C-NMR (50 MHz, CDCl 3 ) δ: 3.57 (≡C—CH 3 ), 23.76 (CH—CH 3 ), 55.83 (OCH 3 ), 55.89 (≡C—CH 2 O), 75.35 (≡C—CH 2 ), 76.40 (Ar—CH—CH 3 ) 81.91 (≡C—CH 3 ), 108.39 (C-2), 114.03 (C-5), 119.73 (C-6). 134.60 (C-1), 145.15 (C-4), 146.75 (C-3).
6.) 3,4-Dimethoxy-1-[1-(pent-3-ynyloxyl)ethyl]benzene
Into a flask, equipped with stirrer, 1.5 g (8.23 mmol) of α-methylveratryl alcohol and 1.4 g (16.46 mmol) of 3-pentyn-1-ol are placed and to the mixture 3.0 ml of the 50 w/v % calcium chloride-1 w/w % hydrochloric acid solution is added, at a fast rate. The mixture is stirred overnight at room temperature, then it is diluted with ether, and the mixture is neutralized with a few drops of 1 M sodium hydroxide solution. The two phases are separated, the aqueous phase is thoroughly extracted with ether. The united organic phase is washed with saturated sodium chloride solution, dried and evaporated.
Yield: 1.9 g (93%). GC (CP 9000, CP-SIL-5CB, 60 m×0.53 mm, 5 ml/min N 2 , FID, 250° C.) t R =5.0 min, approx. 93.2%. IR (CDCl 3 , cm −1 ) υ: 2995, 2974, 2957, 2864, 2838, 1607, 1595, 1510, 1465, 1260, 1163, 1142, 1098, 1027. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.44 (3H, d, J=6.4 Hz, CH—CH 3 ), 1.75 (3H, t, J=2.5 Hz, CH 3 —C≡), 2.37 (2H, m, CH 2 —C≡), 3.38 (2H, t, J=7.2 Hz), 3.87 and 3.89 (altogether 6H , each s, OCH 3 ), 4.38 (2H, q, J=6.4 Hz, Ar—CHO), 6.83 (2H, d, aromatic), 6.90 (1H, s, aromatic). 13 C-NMR(50 MHz, CDCl 3 ) δ: 3.42 (CH 3 —C≡), 20.27 (OCH 2 —CH 2 ), 24.07 (CH—CH 3 ), 55.78 és 55.85 (OCH 3 ), 67.04 (OCH 2 —CH 2 ), 75.93 and 77.78 (Ar—CH—CH 3 , C≡C two signals overlapping), 108.92 (C-2), 110.83 (C-5), 118.52 (C-6), 136.34 (C-1), 148.33 (C-3), 149.13 (C-4).
7.) 1-[1-(3-Butyn-2-yloxy)ethyl]-3,4-dimethoxybenze
Into a flask, equipped with stirrer, 3.0 g (0.0164 mol) of α-methylveratryl alcohol and 3.46 g (0.0493 mol) of 3-butyn-2-ol are placed and to the mixture 1.5 ml of the 50 w/v % of calcium chloride-1 w/w % hydrochloric acid solution is added, at a fast rate. The mixture is stirred overnight at room temperature, then it is diluted with 10 ml of ether, and neutralized with a few drops of 1 M sodium hydroxide solution. The two phases are separated, the aqueous phase is thoroughly extracted with ether. The united organic phase is washed with saturated sodium chloride solution, dried and evaporated. The residue is purified by coloumn chromatography (eluent:hexane-ethyl acetate 4:1, R f =0.41 and 0.36).
The two diastereomers (threo-erythro) were partly separated:
More apolar (major) α-isomer 1.9 g,
60-40 mixture 0.76 g,
More polar, β-isomer 0.32 g.
Ratio of the two isomers, calculated on the basis of the isolated amounts: approx. 3.7:1
Yield: 2.98 g (0.0127 mol, 77.6%). GC (CP 9000, CP-SIL-5CB, 60 m×0.53 mm, 5 ml/min N 2 , FID, 250° C.): α-isomer: t R =3.4 min, approx. 97.27%, β-isomer: t R =3.58 min, approx. 94.26%.
α-isomer:
IR (CHCl 3 , cm −1 ) υ: 3306, 2981, 2934, 2838, 1608, 1595, 1509, 1465, 1464, 1260, 1168, 1141, 1098, 1048, 963, 910, 860, 635. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.39 (3H, d, J=6.6 Hz, ≡CCH—CH 3 ), 1.46 (3H, d, J=6.5 Hz, Ar—CH—CH 3 ), 2.41 (1H, d, J=2 Hz, ≡CH), 3.87 and 3.89 (altogether 6H , each s , OCH 3 ), 3.89 (1H, qd, J=2, 6.6 Hz, ≡CCH), 4.75 (2H, q, J=6.5 Hz, Ar—CH—CH 3 ), 6.80-6.89 (3H, m, aromatic). 13 C-NMR (50 MHz. CDCl 3 ) δ: 22.19 (≡CCH—CH 3 ), 24.15 (Ar—CH—CH 3 ), 55.82 (OCH 3 ), 61.78 (≡C—CHO), 72.44 and 75.17 (≡CH and Ar—CHO), 84.11 (≡C—CH), 109.06 (C-2), 110.89 (C-5), 118.94 (C-6), 135.50 (C-1), 148.49 (C-3), 149.14 (C-4).
β-isomer:
IR(CHCl 3 , cm −1 ) υ: 3307, 2975, 2935, 2838, 1607, 1595, 1511, 1466, 1454, 1261, 1165, 1142, 1094, 1041, 961, 910, 862, 638. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.44 (6H, d, J=6.5 Hz, ≡CCH—CH 3 and Ar—CH—CH 3 ), 2.355 (1H, d, J=2 Hz, ≡CH), 3.87 and 3.89 (altogether 6H, each s, OCH 3 ), 4.23 (1H, qd, J=2, 6.5 Hz, ≡CCH), 4.66 (2H, q, J=6.5 Hz, Ar—CH—CH 3 ), 6.79-6.96 (3H, m, aromatic). 13 C-NMR (50 MHz, CDCl 3 ) δ: 21.83 (≡CCH—CH 3 ), 22.64 (Ar—CH—CH 3 ), 55.79 and 55.86 (OCH 3 ), 62.53 (≡C—CHO), 72.26 and 75.10 (≡CH and Ar—CHO), 84.40 (≡C—CH), 109.43 (C-2), 110.79 (C-5), 118.51 (C-6), 136.19 (C-1), 148.33 (C-3), 148.96 (C-4).
8.) 1-[1-(Prop-2-enyloxy)ethyl]-3,4-dimethoxybenzene, (1-(3′,4′-dimethoxyphenyl)ethyl allyl ether)
Into a flask equipped with stirrer 3.0 3 (0.0164 mol) of α-methylveratryl alcohol and 1.9 g allyl alcohol are placed and to the mixture 1.5 ml of the 50 w/v % calcium chloride-1 w/v % hydrochloric acid solution is added, at a fast rate. The mixture is stirred overnight at room temperature, diluted with ether and neutralized with a few drops of 1 M sodium hydroxide solution. The two phases are separated, the aqueous phase is thoroughly extracted with ether. The united organic phase is washed with saturated sodium chloride solution, dried and evaporated.
Yield: 3.0 g (82.4%). GC (CP 9000, CP-SIL-5CB, 60 m×0.53 mnm, 5 ml/min N 2 , FID, 250° C.) t R =3.4 min approx. 90.3%. IR (CHCl 3 , cm −1 ) υ: 3079, 2996, 2973, 2933, 2860, 2838, 1607, 1595, 1510, 1465, 1443, 1419, 1311, 1260, 1164, 1141, 1089, 1027, 996, 928, 860. 1 H-NMR (200 MNHz, CDCl 3 ) δ: 1.45 (3H, d, J=6.4 Hz, CH 3 ), 3.83 AB mid. (2H, ABdt, J AB =12.7 Hz, J=1.3, 6.0 Hz, OCH 2 CH═), 3.89 and 3.87 (altogether 6H, each s, CH 3 O), 4.41 (2H, q, J=6.4 Hz, CH—O), 5.11-5.29 (2H, m), 5.81-6.0 (1H, m), 6.83 (2H, s), 6.89 (1H, s). 13 C-NMR (50MHz, CDCl 3 ) δ: 24.0 (CH—CH 3 ), 55.77 (OCH 3 ), 69.17 (OCH 2 ═), 108.94 (C-2), 110.82 (C-5), 116.58 (CH═CH 2 ), 118.58 (C-6), 135.0 (C-1), 136.26 (CH═CH 2 ), 148.29 and 149.11 (C-3 and C-4).
9.) 1-[1-(But-2-ynyloxy)ethyl]naphthalene/1-(1-naphthyl)ethyl but-2-ynyl ether/
To a flask equipped with magnetic stirrer, condenser and drying tube filled with calcium chloride, α-methyl-1-naphthyl-methanol (0.86 g, 5 mmol) and 2-butyn-1-ol (0.7 g, 10 mmol are placed and dissolved in 15 ml of dichloroethane. Under stirring at room temperature zinc(II) chloride (0.68 g, 5 mmol) is added to the mixture. The reaction is accompanied by a characteristic change of colour. After 24 hours of reaction the organic phase is washed with 3×5 ml of saturated sodium chloride solution, dried and evaporated. The raw product (1.2 g) is purifed by coloumn chromatography.
Yield: 0.8 (3.57 mmol, 71%). GC 95%. IR (CHCl 3 , cm −1 ) υ: 3052, 2977, 2921, 2856, 1596, 1509, 1444, 1371, 1095, 1078. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.67 (3H, d, J=6.5 Hz, CH 3 —CH), 1.37 (31H, t, J=2.3 Hz, ≡C—CH 3 ), 2.96 and 4.15 (altogether 2H, ABX, J AB =15.0 Hz, J AX =J BX 32 2.3 Hz, OCH 2 —C≡C), 5.40 (1H. q, J=6.5 Hz, C 10 H 7 —CH—O), 7.51 (3H, m), 7.61 (1H, d, J=6.8 Hz), 7.79 (1H, d, J=8.1 Hz), 7.89 (1H, dd, J=7.9, 1.8 Hz), 8.22 (1H, d, J=8.1 Hz) 13 C-NMR (50 MHz, CDCl 3 ) δ: 3.64 (C≡C—CH 3 ), 22.96 (CH 3 —CH), 56.37 (O—CH 2 —C≡C), 74.29 (CH 3 —CH), 75.36 and 82.14 (C≡C), 123.26 (C-8), 123.52, 125.50, 125.85, 127.92, 128.83, 130.78 (C-8a), 133.88 (C-4a), 138.42 (C-1).
10.) General procedure for the preparation of But-2-ynyl benzyl ethers
Into a flask equipped with stirrer 10 mmol of the benzyl alcohol given below and 1.2 g (20 mmol) of 2-butyn-1-ol are placed and to the mixture 1.5 ml of the 50 w/v % calcium chloride-1 w/w % hydrochloric acid solution is added, at a fast rate. The mixture is stirred overnight at room temperature. The reaction is followed by TLC method. The mixture is then diluted with ether and neutralized with a few drops of 1 M sodium hydroxide solution. The two phases are separated, the aqueous phase is thoroughly extracted with ether. The united organic phase is washed with saturated sodium chloride solution, dried and evaporated. The product obtained is purifed by coloumn chromatography.
a.)
Starting benzyl alcohol: 3,4-dimethoxybenzyl alcohol; Product: 3,4-dimethoxybenzyl but-2-ynyl ether; Yield: 85%; Purity (GC): 94%; IR (CDCl 3 , cm −1 ) υ: 3025, 3000, 2956, 2937, 2921, 2855, 2839, 1607, 1595, 1512, 1466, 1443, 1420, 1158, 1140, 1070, 1028. 1 H-NMR (200 MHz, CDCl 3 ) δ: 1.84 (3H, t, J=2.3 Hz, C≡C—CH 3 ), 3.83 and 3.85 (altogether 6H, CH 3 O), 4.08 (2H, q, J=2.3 Hz, OCH 2 C≡C—), 4.48 (2H, s, aryl-CH 2 ), 6.77-6.88 (3H, m, aryl). 13 C-NMR (50 MHz, CDCl 3 ) δ: 3.45 (C≡C—CH 3 ), 55.67 and 55.71 (CH 3 O), 57.31 (OCH 2 C≡C—), 71.22 (aryl-CH 2 ), 75.0 (C≡C—CH 3 ), 82.42 (C≡C—CH 3 ), 110.76 (C-2), 111.23 (C-5), 120.54 (C-6), 130.05 (C-1), 148.58 (C-4), 148.88 (C-3).
b.)
Starting benzyl alcohol: (3,4-dimethoxyphenyl)dimethylcarbinol; Product: 1-(3,4-dimethoxyphenyl)-1-methylethyl 2-(but-2-ynyl) ether; Yield: 85%; Purity (GC): 94%.
c.)
Starting benzyl alcohol: 1-[1-hydroxypropyl]-3,4-dimethoxybenzene; Product: 1-[1-(2-butynyloxy)-propyl]-3,4-dimthoxybenzene; Yield: 87%; Purity (GC): CP 9000, CP-SIL-5CB, 60 m×0.53 μm, 5 ml/min N 2 , FID, 220° C. t R =13.0 min, >95%. IR (CHCl 3 , cm −1 ) υ: 2999, 2959, 2935, 2875, 2856, 2839, 2240, 1608, 1595, 1513. 1465, 1261, 1234, 1162, 1142, 1061, 1028. 1 H-NMR (200 MHz, CDCl 3 ) δ: 0.84 (3H, t, J=7.4 Hz, CH 2 CH 3 ), 1.65 and 1.83 (altogether 2H, each m, CH 2 C 3 ), 1.82 (3H, t, J=2.3 Hz, C≡C—CH 3 ), 3.84 and 3.86 (altogether 6H, s, CH 3 O), 3.78 and 3.99 (altogether 2H, ABX 3 , J AB =15.0 Hz, J AX =J BX =2.3 Hz, OCH 2 ), 4.22 (1H, t, J=6.8 Hz, CH—O), 6.80-6.83 (3H, m, aromatic) (signals of ethyl acetate can be seen at 1.22 (t), 2.01 (s) and 4.08 (q) ppm). 13 C-NMR (50 MHz, CDCl 3 ) δ: 3.55 (C≡C—CH 3 ), 10.23 (CH 2 CH 3 ), 30.58 (CH 2 CH 3 ), 55.77 (OCH 3 ), 56.03 (OCH 2 ), 75.41 (C≡C—CH 3 ), 81.71 (C≡C—CH 3 ), 82.24 (CH—O), 109.34, 110.64 (C-2, C-5), 119.63 (C-6), 133.95 (C-1), 148.44 and 149.09 (C-3, C-4).
d.)
Starting benzyl alcohol: 1-[1-hydroxy-2-methylpropyl]-3,4-dimethoxybenzene Product: 1-[1-(2-butynyloxy)-2-methylpropyl]-3,4-dimethoxybenzene; Yield: 85%; Purity (GC): CP 9000, CP-SIL-5CB, 60 m×0.53 μm, 5 ml/min N 2 , FID, 220° C., t R =14.0.0 min, >91%. IR (CDCl 3 , cm −1 ) υ: 3029, 2995, 2958, 2937, 2871, 2857, 2839, 2238, 1606, 1595, 1510, 1466, 1443, 1420, 1263, 1238, 1157,1142, 1062, 1028. 1 H-NMR (400 MHz, CDCl 3 ) δ: 0.65 and 0.97 (altogether 6H, each d, J=6.8 Hz, CH(CH 3 ) 2 ), 1.77 (3H, t, J=2.3 Hz, C≡C—CH 3 ), 1.87 (1H, m, CH(CH 3 ) 2 ), 3.80 and 3.81 (altogether 6H, each s, OCH 3 ), 3.71 and 3.95 (altogether 2H, ABX 3 , J AB =15.0 Hz, J AX =J BX =2.3 Hz, OCH 2 ), 3.90 (1H, d, J=8.1 Hz, CH—O), 6.68-6.78 (3H, m, aromatic). 13 C-NMR (100 MHz, CDCl 3 ) δ: 3.39 (C≡C—CH 3 ), 18.87 and 19.16 ((CH(CH 3 ) 2 ), 34.32 (CH(CH 3 ) 2 ), 55.61 (OCH 3 ), 56.11 (OCH 2 ), 75.44 (C≡C—CH 3 ), 81.37 (C≡C—CH 3 ), 86.25 (CH—O), 109.76 (C-5), 110.32 (C-2), 120.19 (C-6), 132.91 (C-1), 148.24 (C-4) és 148.80 (C-3).
e.)
Starting benzyl alcohol: 5-[1-hydroxyethyl]-1,3-benzodioxol; Product: 5-[1-(2-butynyloxy)ethyl]-1,3-benzodioxol; Yield: 84%; Purity (GC): 94%; IR (CHCl 3 , cm −1 ) υ: 2979, 2921, 2882, 1609, 1502, 1486, 1441, 1079, 1041, 941. 1 H-NMR (400 MHz, CDCl 3 ) δ: 1.41 (3H, d, J=6.5 Hz, CHCH 3 ), 1.83 (3H, t, J=2.3 Hz, C≡C—CH 3 ), 3.80 and 3.99 (altogether 2H, ABX 3 , J AB =15 Hz, J AX =J BX =2.3 Hz, OCH 2 ), 4.51 (1H, q, J=6.5 Hz, CHCH 3 ), 5.92 (2H, AB, OCH 2 O), 6.74 (2H, AB, H-6, H-7), 6.83 (1H, s, H-4). 13 C-NMR (100 MHz, CDCl 3 ) δ: 3.50 (C≡C—CH 3 ), 23.67 (CHCH 3 ), 55.80 (OCH 2 ), 75.18 (C≡C—CH 3 ), 76.16 (CH—O), 81.93 (C≡C—CH 3 ), 100.84 (OCH 2 O), 106.47, 107.88 (C-4, 7), 119.90 (C-6), 136.63 (C-5), 146.94 and 147.77 (C-3a, 7a).
f.)
Starting benzyl alcohol: 1-[1-hydroxyethyl]-3,4-diethoxybenzene; Yield: 1-[1-(2-butynyloxy)ethyl]-3,4-diethoxybenzene; Yield: 86%; Purity (GC): 93%;
g.)
Starting benzyl alcohol: 1-[1-hydroxyethyl]-3,4-dimethoxy-6-propylbenzene; Product: 1-[1-(2-Butynyloxy)ethyl]-3,4-dimethoxy-6-propyl-benzene; Yield: 73%; Purit (GC): CP 9000, CP-SIL-5CB, 60 m×0.53 mm, 5 ml/min N 2 , FID, 250° C., t R =6.7 min, kb 95.4%. IR(CDCl 3 , cm −1 ) υ: 2961, 2933, 2873, 2331, 1610, 1511, 1466, 1261, 1132, 1098, 1047. 1 H-NMR (400 MHz, CDCl 3 ) δ: 0.96 (3H, t, J=7.3 Hz, CH 3 ), 1.41 (3H, d, J=6.4 Hz, CH 3 CHO), 1.58 (2H, sextet, J=7.4 Hz, CH 2 —CH 3 ), 1.81 (3H, t, J=2.5 Hz, CH 3 —C≡), 2.54 (2H, m, CH 2 —Ar), 3.78 and 3.98 (2H, ABX 3 , J AB =15.0 Hz, J AX =J BX =2.3 Hz, ≡C—CH 2 O), 3.83 (6H, s, OCH 3 ), 4.86 (H, q, J=6.5 Hz, Ar—CHO), 6.60 and 6.91 (2H, s, aryl). 13 C-NMR (100 MHz, CDCl 3 ) δ: 3.46 (≡C—CH 3 ), 14.05 (CH 3 ), 23.70 and 24.97 (CH 2 —CH 3 and CH 3 CHOH), 34.03 (aryl-CH 2 ), 55.62, 55.69 and 55.80 (OCH 3 and ≡C—CH 2 O) 71.60 (Ar—CH—CH 3 ), 75.46 (≡C—CH 2 ), 81.84 (≡C—CH 3 ), 108.45, 112.32 (C-2, C-5), 132.29, 132.33 (C-6, C-1), 147.60, 147.79 (C-4, C-3).
11.) 5-[(2-butynyloxy)methyl]-1,3-benzodioxol
To a flask equipped with magnetic stirred condenser and drying tube filled with calcium chloride, 3.0 g, (13.95 mmol) of piperonyl bromide, 2.0 g (27.9 mmol) of 2-butyn-1-ol and 50 ml of dichloroethane are placed. After the addition of zinc(II) oxide (1.1 g, 13.5 mmol) the suspension is stirred at room temperature for 1 hour. The reaction is accompanied by a characteristic chance of colour. The mixture is then filtered, the filtrate is evaporated. The residual oil is dissolved in 50 ml of ether, washed within 2×10 ml of water, dried and evaporated. Yield 2.3 g (11.2 mmol, 80.7%), GC 82%. IR(CHCl 3 , cm −1 ) υ: 2997, 2946, 2921, 2888, 2376, 1609, 1503, 1491, 1445, 1251, 1099, 1070, 1042, 937, 865, 810; 1 H-NMR (400 MHz, CDCl 3 ) δ: 1.87 (3H, t, J=2.3 Hz, Me), 4.10 (2H, q, J=2.3 Hz, O—CH 2 —C≡), 4.47, (2H, s, O—CH 2 —Ar), 5.94 (2H, s, O—CH 2 —O), 6.76 (1H, d, J=8 Hz, H-7), 6.81 (1H, dd, J=8.15 Hz, H-6), 6.86 (1H, J=1.5 Hz, H-4); 13 C-NMR (100 MHz, CDCl 3 ) δ: 3.52 (Me), 57.29 (O—CH 2 —C≡), 71.15 (O—CH 2 —Ar), 82.54 (CH 3 —C≡), 100.9 C-2, 107.95, 108.71 (C-4, 7), 121.66 (C-6), 131.39, (C-5), 147.15, 147.66 (C3a, C-7a);
12.) 1-[(2-butynyloxy)methyl]naphthalene
To a flask equipped with magnetic stirrer, condenser and drying tube filled with calcium chloride, bromomethylnaphthalene (1.0 g, 4.52 mmol), 2-butyn-1-ol (0.63 g, 9 mmol) and 10 ml of dichloroethane are placed. After the addition of zinc(II) oxide (4.0 g, 4.52 mmol) the suspension is stirred for 1 hour at room temperature, then it is refluxed for 1 hour. The reaction is accompanied by a characteristic change of colour. The mixture is then filtered, the filtrate is evaporated. The residual oil is dissolved in 15 ml of ether, washed with 2×50 ml of water, dried and evaporated. The product is purified by coloumn chromatography. Purity (GC) 95%. IR (CHCl 3 , cm −1 ) υ: 3044, 3001, 2945, 2920, 2854, 1598, 1509, 1356, 1166, 1086, 1067; 1 H-NMR (400 MHz, CDCl 3 ) δ: 1.93 (3H, t, J=2.3 Hz, C≡C—CH 3 ), 4.22 (2H, q, J=2.1 Hz, O—CH 2 —C≡C), 5.06 (2H, s, C 10 H 7 —CH 2 —O), 7.45 (1H, t, J=8 Hz), 7.53 (3H, m), 7.84 (1H, d, J=8.1 Hz), 7.88 (3H, m), 7.88 (1H, d, J=7.7 Hz), 8.19 (1H, d, J=8.2 Hz); 13 C-NMR (100 MHz, CDCl 3 ) δ: 3.6 (C≡C—CH 3 ), 57.71 (O—CH 2 —C≡C), 69.72 C 10 H 7 —CH 2 —O), 75.10 (O—CH 2 —C≡C), 82.76 (O—CH 2 —C≡C), 124.03, 125.10, 125.72, 126.19, 126.85, 128.43, 128.72, 131.79 (C-8a), 133.06, 133.70.
13.) 5-[2-(2-butoxyethoxy)ethoxymethyl]-6-propyl-1,3-benzodioxol, PBO
a.)
To a flask equipped with magnetic stirrer, condenser and drying tube filled with calcium chloride, 2.98 g (14,02 mmol) of 5-chloromethyldihydrosafrol, 2,72 g (16,82 mmol) diethylene glycol monobutyl ether and 20 ml of dichloroethane are placed. After the addition of zinc(II) oxide (1.22 g, 15.0 mmol) the suspension is stirred for 24 hours at room temperature. The reaction is followed by TLC method and after the disappearance of the starting benzyl chloride the mixture is filtered, the filtrate is evaporated. The residual oil is dissolved in 25 ml of ether, washed with 2×50 ml of water, dried and evaporated. The product is distilled in vacuo. Bp: 180° C./1 Hgmm. The material is identical with the marketed PBO. Yield 4,0 g (90%). Purity (GC) 98%.
b.)
To a flask equipped with magnetic stirrer, condenser and drying tube filled with calcium chloride, 2,12 g (10,0 mmol) of 5-chloromethyldihydrosafrol, 2,42 g (15,0 mmol) diethylene glycol monobutyl ether are placed. After the addition of 0.97 g (15.0 mmol) of zinc(II) oxide the suspension is stirred for 12 hours at room temperature. The reaction is followed by TLC method and after the disappearance of the starting benzyl chloride the mixture is diluted with diethyl ether, filtered, the filtrate is washed with 2×50 ml of water, dried and evaporated. The product is distilled in vacuo. Bp: 180° C./1 Hgmm. The material is identical with the marketed PBO. Yield 2,8 g (91%). Purity (GC) 98%.
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The subject matter of the invention is the process for the preparation of mixed ethers of formula I, wherein Ar represents an aromatic or one or more heteroatom-containing moiety, optionally substituted by one or more C 1-4 alkoxy, methylenedioxy, C 1-4 alkyl, halogen, C 1-4 haloalkyl or nitro-group, and/or condensed with a benzene ring; R 1 and R 2 independently mean hydrogen, C 1-4 alkyl, C 1-4 haloalkyl, C 2-4 alkenyl, phenyl, substituted phenyl, C 3-6 cycloalkyl group, R 3 means C 3-6 alkynyl, optionally substituted by one or more C 1-6 alkyl, C 3-6 alkenyl, C 3-6 alkynyl, C 1-6 haloalkyl group, or halogen atom, R 3 also means a C 1-4 alkyloxy-C 1-4 alkyloxy-C 1-4 alkyl group. The process comprises the step of reacting the compounds of general formula II with 1 to 3 molar equivalent of the alcohol of general formula IlI in the presence of acid, a Lewis acid, a metal oxide or a metal carbonate, X means hydroxy, halogen or sulphonester leaving group, the resulting ether of general formula I is isolated, if desired, stabilized by the addition of a base and/or an antioxidant; and if desired the excess of the alcohol is recovered.
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BACKGROUND OF THE INVENTION
The principal aspect, the present invention comprises a medical instrument or speculum and, more particularly, a speculum of the type which may be used for vaginal examination; however, the principal of the invention may be utilized in instruments designed for other examination purposes such as oral examination, aural cavity examination and the like.
The utilization of medical instruments which facilitate the physical examination of a patient and generally described as a speculum or endoscopic instrument comprise a well known technique in medical examination procedures. An endoscope instrument used for such purposes is disclosed in U.S. Pat. No. 605,652 in the name of Pitt. There disclosed instrument is comprised of scissors-type handles which are manually operated to open and close speculum or endoscopic jaws having a semi-conical configuration. A light source is mounted within the jaws to facilitate the examination process when the jaws are inserted into a cavity and caused to spread by operation of the manual handles.
Various other instruments of this nature have been the subject of patent protection. Strauss, in U.S. Pat. No. 1,094,575, discloses a speculum of similar construction utilized for dental and oral examination purposes. Deutsch, in U.S. Pat. No. 3,664,330, discloses a speculum instrument which includes fiber optic elements carried in speculum jaw members which are designed to extend into a body orifice to provide illumination. McDonald, in U.S. Pat. No. 3,762,400, discloses a medical instrument of a similar configuration wherein the speculum members or jaws include removable legs adapted to receive fiber optic elements or bundles. The device disclosed in the McDonald patent is useful for vaginal inspection.
Over the years, there have been numerous additional patents granted for other instruments of this general nature, including the following:
__________________________________________________________________________Pat. No. Title Inventor Issue Date__________________________________________________________________________ 471,990 Endoscopic Instrument John W. Daily March 29, 1892 559,122 Endoscopic Instrument John W. Daily April 28, 1896 872,343 Speculum Frank E. Griswold December 3, 1907 872,344 Speculum Frank E. Griswold December 3, 19071,222,478 Speculum P. A. Sheaff April 10, 19171,706,500 Surgical Retractor H. J. Smith March 26, 19292,247,258 Surgical Instrument B. J. Shepard June 24, 19412,482,971 Self-Illuminated Trans- K. K. Golson September 27, 1949 parent Proctoscope2,690,745 Tongue Blade C. D. Govan October 5, 19543,131,690 Fiber Optics Devices R. E. Innis et al. May 5, 19643,324,850 Illuminated Vaginal J. E. Gunning et al. June 13, 1967 Speculum with Rotatable Cam Pivoting and Locking Means3,532,088 Speculum Instrument John M. Fiore October 6, 19703,592,199 Autoclavable Surgical Ralph G. Ostensen July 13, 1971 Instrument Illumination3,716,047 Disposable Light- W. C. Moore et al. February 13, 1973 Conductive Speculum3,744,481 Medical Examining Bernard McDonald July 10, 1973 Method and Means3,789,835 Illuminating Attachments Robert S. Whitman February 5, 1974 For Vaginal Speculum3,796,214 Perineal Retractor Rachel D. Davis March 12, 19743,851,642 Medical Examining Bernard McDonald December 3, 1974 Instrument4,086,919 Laryngoscope James R. Bullard May 2, 1978DE 2,302,614 Metall et al. January 19, 1973Swiss 273809 Medical Instrument For Emile Vaurillon June 19, 1951 Examining Human Body CavitiesUK 25,040 Light Speculum For R. Hammerschlag November 3, 1913 Gynecological Purposes__________________________________________________________________________
While many instruments have been developed in this particular field, there has remained the need for a speculum instrument which is highly adjustable, capable of utilizing fiber optic lighting elements, and which includes disposable blades or speculum members that are inexpensive yet highly utilitarian.
SUMMARY OF THE INVENTION
Briefly, the present invention comprises a speculum which includes a first scissors arm pivotally connected to a second scissors arm. Each arm is substantially the mirror image of the other and includes a handle or manual gripping end, a support shaft end and a pivot intermediate the ends. Preferably a support shaft extends substantially transversely from the support shaft end of each scissors member and has a keyed cross sectional shape; for example, the support shaft is a splined shaft. Speculum jaw members or blades include throughbores at one end compatible with the posts or shafts extending from the scissors arms. Thus the bore of each of the speculum jaw members or blades is likewise configured or keyed so as to be adjustably positioned or orientable on the shaft. In this manner, the angular relationship of the jaw members or blades may be adjusted slightly depending upon medical needs or physician preference. A fiber optic package or bundle is included within each of the blades or jaw members. The jaw members are fabricated from sterile sanitary materials such as molded plastic materials and are disposable. As an additional feature of the invention, the speculum blades or jaw members may include a shape memory cylinder or element which fits over the blades, whereby upon insertion of the blades and cylinder into a body cavity, an adjustment of the cylinder may be made so as to cause the forward end of the cylinder to expand in a controlled fashion, thereby expanding the body cavity under examination in a desired manner to facilitate the examination procedure.
Thus it is the object of the invention to provide an approved medical instrument or speculum.
Yet a further object of the invention is to provide an improved speculum apparatus which permits manual operation of scissors members to spread speculum jaws that are replaceable and adjustable.
Yet a further object of the invention is to provide a speculum member having speculum blades which are removable and replaceable and which when removed or replaced are adjustable so as to adjust the angle or orientation of the blades relative to one another.
Yet a further object of the invention is to provide speculum instrument wherein the speculum blades include a self-contained energy source and fiber optic light elements to facilitate the use of the instrument when inspecting a cavity.
Another object of the invention is to provide an improved speculum instrument which includes speculum blades or speculum jaw members useful with a shape memory element which enhances the opportunity to utilize the speculum for diagnostic purposes.
These and other objects, advantages and features of the invention will be set forth in a detailed description as follows.
BRIEF DESCRIPTION OF THE DRAWING
In the detailed description that follows, reference will be made to the drawing comprised of the following figures:
FIG. 1 is an exploded isometric view of an embodiment of the speculum instrument of the invention;
FIG. 2 is an isometric view of the instrument of FIG. 1 assembled for utilization;
FIG. 3 is a front end view of the speculum blades or speculum jaw members utilized in the instrument of the invention;
FIG. 4 is a cross sectional view of the splined shaft utilized for mounting speculum blade members taken along the line 4--4 in FIG. 2,
FIG. 5 is an isometric view of a sleeve which may be used co-jointly with the speculum instrument of the invention, said sleeve including a shape memory feature; and
FIG. 6 is an isometric view of the sleeve of FIG. 5 wherein the speculum blade members are partially withdrawn from the sleeve so as to permit the shape memory feature to be activated, thereby enhancing cavity size by means of the instrument and sleeve.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The medical instrument or speculum of the present invention includes a first scissors arm 10 and a second compatible scissors arm 12 which is substantially a mirror image of arm 10. The scissors arm 10 includes a manually operable end or handle 14 which is shaped as to receive the fingers of a medical practitioner. Similarly, scissors arm 12 includes a manually operable handle or end 16. Scissors arm 10 further includes a pivot connection 18 as does arm 12 include a pivot connection 20. The pivot connections 18, 20 overlap and join together so that actuation of the handles 14, 16 will effect an appropriate scissors or spreading action. In the preferred embodiment, the arm 10 includes a projecting locking member 22 which cooperates with locking member 24 projecting from the scissors arm 12. The members 22 and 24 overlap one another and include serrated or locking ribs such that when the handles 14 and 16 are manually moved one toward the other, handles 14, 16 remain in a fixed or locked position so that the speculum jaw members will remain fixed in an open or locked position. A manually operated locking release tab 23 is provided to release one of the locking members 22 from the other locking member 24 when desired. Each scissors arm 10 and 12 further includes a projecting forward shaft or bracket support section or arm such as arm 26 of scissors arm 10 and arm 28 of scissors arm 12. The elements so far described are generally coplanar.
The support ends 26 and 28 of the respective scissors arms 10 and 12 include an upwardly projecting splined shaft 30 and 32 respectively. Each splined shaft 30 and 32 typically has a uniform cross section shape depicted in FIG. 4 by way of example. The particular configuration of the splined shaft 30, 32 depicted in FIG. 4 is not a limiting feature of the invention. Each shaft 30, 32 is shaped or keyed so as to maintain speculum members 34, 36 (described below) locked onto or attached to or supported by each shaft or post 30 and 32 respectively so as to be removable and replaceable and fixed or oriented in a fixed position when mounted on post 30, 32. The shafts 30, 32 may extend transversely from the ends 26, 28. Thus, the shafts 30, 32 extend at an angle from the plane of the arms 10, 12.
Thus mounted upon each post or shaft 30 and 32 is a separate speculum jaw member 34 and 36. In the practice of the invention, the speculum members 34 and 36 are substantially identical or mirror images of one another. In fact, in one embodiment, the members 34 and 36 are identical and may be reversed in orientation so as to be mounted on either post 30 or post 32. However, it is not necessary that the speculum members be identical. Thus a right-handed and a left-handed speculum member may be manufactured so as to provide for specialized operation of the instrument. The right-handed speculum member, for example, may be foreshortened relative to the one on the left side. Thus the shapes and size of the separate speculum members may be varied depending upon medical needs. The number and intensity of the fiber optic packages described below in each of the speculum members may be varied or adjusted. The speculum members may include auxiliary passageways for insertion of medicaments, for example. Nonetheless, a description of speculum member, such as the left side speculum member 34, is generally applicable to the right side member 36.
Referring to the left side speculum member 34, the member 34 is generally comprised of a semi-cylindrical pre-molded or preformed material. Typically a plastic material may be used although it is possible to use other materials. The speculum member 34 includes a semi-cylindrical body 38 and a forward frusto-conical end 40 which terminates in a semi-elliptical or semi-cylindrical forward end 42. Fiber optic bundles or fibers 44 and 46 extend as light elements either on an internal surface 48 of the speculum member 34 or are retained within passages within the member 34. The material used to manufacture the speculum member 34 may be transparent or translucent so as to enhance the utility of the fiber optic light elements 44, 46.
A bracket member or bracket housing 50 is provided at the mounting end of the speculum blade or jaw member 34. The bracket 50 is connected to and supports the body 38. The bracket 50 also preferably includes a power source, such as a battery 52, which is connected to and provides power to the fiber optic light elements 44 and 46. Importantly, the bracket 50 includes a bore 54. The bore 54 has a cross-sectional shape, substantially identical to the cross-sectional shape of the post or shaft 32 such as depicted in FIG. 4 so that the speculum member 34 may be mounted on shaft 30 by sliding the opening or bore 54 over the post or shaft 30 and extend in a perpendicular direction from the shaft 30. Note that because of the configuration of the cross section of the post 30 and bore 54, it is possible to adjust the angle of attachment of the speculum member 34 relative to the angle of the attachment of the speculum member 36. Thus the members 34 and 36 may be aligned so as to be angled toward one another at their forward ends. Alternatively, they may be aligned in a parallel fashion or they may be splayed or extended outwardly relative to one another. Additionally, since the bore 54 may be a throughbore, the speculum member 34 may be inserted on either post 30 or 32. That is, the members 34 and 36 are reversible when a throughbore 54 of uniform cross section shape and size is provided and posts 30, 32 are identical.
However, it is possible to design the posts or shafts 30 and 32 so as to be distinct or different thereby keying left side and right side speculum members independently to posts 30 and 32. Further, it is possible to construct bore 54 so as to have a distinct configuration at each end and thus be compatible with distinct posts 30 and 32 should that be a desired feature.
In other words, by way of example, but not limitation, if the bore 54 includes a section or length at one end which has a cross section identical to the cross section of the shaft 30 and the shaft 30 is foreshortened or only one-half the length of the bore 54, then the member 34 can be fitted appropriately on the shaft 30 in a left side configuration as shown in FIG. 1. Then if the upper half of the bore 54 is configured so as to be compatible only with the configuration of a post 32 extending halfway therethrough and associated with the right hand side, the positioning of the speculum member 34 or the right hand side can be assured. Various other combinations and permutations of bore 54 configuration and shaft 30, 32 configuration may be utilized to accommodate desired orientations and assembly of speculum members 34, 36 to the respective shafts 30 and 32.
FIGS. 5 and 6 illustrate a further feature of the invention. There a cylindrical or elliptical or other closed sleeve member 60 is fitted over the speculum members 34 and 36 for insertion into the appropriate body cavity. The speculum members 34 and 36 may then be partially, longitudinally withdrawn from the sleeve 60. The sleeve 60 includes parallel segments 62 which are arranged circumferentially about the forward end 64 of the sleeve 60. The segments 62 have a shape memory characteristic and will, upon removal of blades 34, 36, balloon outwardly thereby smoothing out the contours of the cavity to provide for enhanced inspection and access. Again, the material utilized for the sleeve 60 may be transparent or translucent to enhance inspection.
While there has been set forth a preferred embodiment of the invention, it is understood that various changes may be made to the component or structural parts and their relationship including changes of the type described herein. Thus the invention is to be limited only by the following claims and their equivalents.
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A speculum includes manually operated scissor arms with keyed shafts at the ends of each arm adapted to receive speculum jaw or blade members supported on the shaft in a desired, adjustable orientation. The speculum blades include a self-contained fiber optic light source. An optional sleeve with shape memory characteristics may be used in combination with the speculum jaw members.
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[0001] This invention relates to peptide sequence tags used to elicit antibodies, which can be used to detect defined families of proteins.
[0002] Natural populations of phytoplankton include representatives of numerous species of cyanobacteria, diatoms, green algae and other groups. Nevertheless many of these species share core biochemical pathways supporting primary productivity and elemental cycling (Bryant, 1994; Falkowski & Raven, 1997). To assess the gross capacity for key metabolic transformations in aquatic habitats, and to track acclimatory changes in these capacities, researchers require reagents to quantitatively detect all members of a functional class of enzymes (Bouchard et al., 2002; Schofield et al., 2002), for example the RbcL (RUBISCO) enzyme responsible for carbon fixation in all photosynthetic organisms. Different members of the organism population will contain somewhat different versions of the RbcL enzyme, which nevertheless share similar core properties and shared conserved regions (ncbi.nlm.nih.gov). Conventional immunological detection uses an antibody raised against one particular protein from one species, which will then bind with variable affinity to other related proteins depending on their antigenic similarity to the initial target molecule (Orellana & Perry, 1992). This is problematic because change in immunological signals could result from: a) changes in the level of the targets b) changes in the population composition resulting in shifts in the specific mix of target molecules present or c) a combination of (a) and (b).
[0003] Conventional antibodies are raised against two classes of protein targets; namely (a) purified or over-expressed protein from a particular species, and (b) a peptide selected to match the sequence of a region of a particular protein. Such antibodies are generally raised against proteins from a model species, and show variable cross-reactivity to related proteins from other species. It is not practical to develop individual antibodies to detect each protein of interest from each strain in a population, many of which are poorly characterized or unknown, and even unculturable (Staley & Reysenbach 2002). Most of the protein families of interest in cyanobacteria and phytoplankton are also highly conserved in plants so that the same detection system can meet needs for standard antibodies in plant sciences.
[0004] Thus, a need exists for a set of peptide targets to elicit production of a set of antibodies to detect key proteins involved, inter alia, in photosynthetic activity. A system should be able to evenly and universally recognize all members of a defined enzyme family or subfamily based on shared characteristics.
[0005] The above defined need is met by the present invention which provides a method for detecting the presence of members of the target protein family in a sample comprising the steps of:
[0006] (a) identifying and obtaining a peptide sequence tag conserved for all sequences of members of the target protein family, and exclusive to the target protein family;
[0007] (b) assessing the tag for immunogenicity potential
[0008] (c) utilizing the tag to elicit the production of antibodies; and
[0009] (d) using the antibodies to measure the concentration of members of the target protein family in a sample.
[0010] The invention also provides a peptide sequence tag selected from the group consisting of
SEQ ID NO: 1 SEQ ID NO: 9 SEQ ID NO: 2 SEQ ID NO: 10 SEQ ID NO: 3 SEQ ID NO: 11 SEQ ID NO: 4 SEQ ID NO: 12 SEQ ID NO: 5 SEQ ID NO: 13 SEQ ID NO: 6 SEQ ID NO: 14 SEQ ID NO: 7 SEQ ID NO: 15 SEQ ID NO: 8 SEQ ID NO: 16
[0011] In accordance with another aspect of the invention, the invention provides a method for detecting the presence of a target protein in a sample comprising the steps of:
[0012] (a) identifying and obtaining a peptide sequence tag conserved for all members of and exclusive to a protein family;
[0013] (b) assessing the tag for immunogenicity; and
[0014] (c) synthesizing the tag provided it possesses a predetermined level of immunogenicity.
[0015] (d) utilizing the tag to elicit the production antibodies; and
[0016] (e) using the antibodies to provide an indication of protein concentration in a sample.
[0017] According to yet another aspect, the invention provides a method of using a peptide sequence tag for coupling to column matrice materials for affinity purification of the global antibodies produced according to the invention.
[0018] According to yet another aspect, there is provided a method of developing characterized concentration standards for quantitation of the concentration of target proteins in samples by comparison to the concentration standards comprising the steps of;
[0019] (a) coupling a defined molar quantity of protein carrier molecule to a defined molar quantity of peptide sequence tag selected from the group consisting of
SEQ ID NO: 1 SEQ ID NO: 9 SEQ ID NO: 2 SEQ ID NO: 10 SEQ ID NO: 3 SEQ ID NO: 11 SEQ ID NO: 4 SEQ ID NO: 12 SEQ ID NO: 5 SEQ ID NO: 13 SEQ ID NO: 6 SEQ ID NO: 14 SEQ ID NO: 7 SEQ ID NO: 15 SEQ ID NO: 8 SEQ ID NO: 16
[0020] (b) subjecting a known molar quantity of the coupled complex from (a) to electrophoretic separation in parallel SDS-PAGE gel lanes with protein extracts containing members of the target protein family, followed by electrophoretic transfer to a membrane
[0021] (c) immunodetection using a global antibody produced according to the above-defined method of the coupled standard and any members of the target protein family identified by the peptide sequence tag and
[0022] (d) using an immunological signal from the known molar quantity of coupled complex as a standard for measuring the molar quantity of members of the target protein family present in the protein extracts.
[0023] In a still further aspect, there is provided a method for quantitation of members of the target protein families in multiple samples using Enzyme-Linked ImmunoSorbent Assay kits using on characterized global antibodies produced according to the above-defined method and quantitation standards produced according to the method defined in the preceding paragraph.
[0024] In another aspect, there is provided a method for eliciting production of monoclonal, transgenic or synthetic antibodies using peptide sequence tags produced according to the above defined method and standard immunological protocols.
[0025] In a further aspect, there is provided a method for affinity screening of libraries of reagents to detect specific reagent binding to a peptide sequence tag produced according to the above defined method and immobilized on a support matrice; and
[0026] testing reagents binding to the immobilized peptide sequence tag for affinity binding to members of the target protein families.
[0027] In a still further embodiment, there is provided a method to use affinity binding using global antibodies produced according to the above-defined method to capture target proteins from complex mixtures for subsequent analyses of the specific sequences of target proteins present in the mixture using mass spectroscopy.
[0028] In yet another embodiment, there is provided a method to use affinity binding using global antibodies produced according to the above defined method to capture and remove target proteins from complex mixtures to lower interference with detection and analyses of other less abundant protein classes in proteomics applications such as two dimensional isoelectric focusing/SDS-PAGE and subsequent mass spectroscopic analyses of protein sequences.
[0029] In general terms, the inventors have designed a set of peptide targets or peptide sequence tags which elicit production of a set of antibodies for detecting key proteins involved in photosynthetic productivity. The inventors chose target protein families based on scientific interest and wide applicability. They have found and aligned sequences from public databases to detect peptide sequence tags of 6-25 amino acids which are conserved in all known members of the target protein family, and use bioinformatic analyses to determine if the conserved peptides are unique to the target protein family. The peptide sequence tags are assessed for potential immunogenicity, feasibility of synthesis, solubility and stability; avoiding sequences that are targets for known or putative post-translational modification in proteins. Selected peptide sequence tags are synthesized, coupled to a carrier and used to elicit antibody production. The specificity and titre of the antibodies were then listed. A set of antibodies increases the utility of the system by allowing comprehensive detection of key molecules in a sample, population or community. The target protein families were selected based on their core roles in the biosphere and their interest and importance for environmental research, modelling, and monitoring.
[0030] Public sequence databases were scanned for all published sequences of proteins in a given family (http://www.expasy.ch; http://www.ncbi.nlm.nih.gov). The sequences of all published members of each target protein family were aligned (Corpet, 1988). Peptide sequence tags of 6-25 amino acids were selected whose sequences are conserved in all known members of the target protein or sub-family. The peptide sequence tags were tested to determine exclusivity to the target protein family using short-peptide BLAST searches of sequence databases (Altschul et al., 2001). The position of each potential peptide sequence tag in a given protein family was analyzed to ensure it is maintained in the mature proteins, and to avoid regions of the proteins known or suspected to undergo post-translational modifications such as glycosylation that could interfere with later antibody recognition of the mature proteins. The peptide sequence tags are screened for antigenic potential using peptide property prediction algorithms, and to assess their feasibility for syntheses, solubility and stability based on amino acid composition. In summary the chosen peptide sequence tags are conserved in all published members of the defined target protein family or subfamily, do not align significantly with members of other known protein families, and have acceptable predicted antigenic and synthesis properties
[0031] The selected peptide sequence tags are synthesized. The peptide sequence tags are then coupled to appropriate immunogenic carrier molecules, typically Keyhole Limpet Hemocyanin, and the complexes are used to elicit production of IgY antibodies in hens. The IgY fraction is separated from the eggs of the immunized hens and the fraction is screened using Enzyme-Linked ImmunoSorbent Assays (ELISA) for binding to the original peptide target. Each IgY production run generates sufficient antibody for hundreds of thousands of immunodetections. Additional hens can be immunized to generate further comparable antibody preparations and for pooling of antibody preparations from multiple hens.
[0032] Members of the target protein family are extracted from a range of species, separated by SDS-polyacrylamide gel electrophoresis, electrophoretically transferred to membranes and immnunoblotting is used to characterize the binding of the antibodies to a range of members of the target protein family. Antibody preparations with good target affinity but which show non-specific binding to other proteins are subjected to affinity purification followed by re-characterization to attempt to improve specificity.
[0033] The novel antibodies can be applied to detect major proteins in a range of species, including uncharacterized species, with confidence that the detection affinity of the antibody is standard for all denatured members of the target protein family. Therefore a quantity standard protein from one species or a synthetic quantity standard can be used for comparative quantitation of members of the protein family from other species.
DETAILED DESCRIPTION OF INVENTION
[0034] Peptide sequence tags designed for eliciting production of global antibodies binding all members of defined protein families or subfamilies.
[0035] In the following, all peptides are written according to convention from amino terminus to carboxy terminus using the standard single letter amino acid code. All peptides are based on alignments of protein sequences accessed through the NCBI (ncbi.nlm.nih.gov) and SwissProt (expasy.ch) public databases. Where present a lower-case “c” indicates a terminal cysteine not present in the original protein family but added for chemical coupling to the immunogenic carrier molecule, usually Keyhole Limpet Hemocyanin. An upper case terminal “C” represents a cysteine present in the original protein, but also used for chemical coupling to the immunogenic carrier molecule.
[0036] 1. PsbA: EVMHERNAHN FPLDc (SEQ ID NO:1) Photosystem II is the ultimate source of almost all biosynthetic reductant in the biosphere. The PsbA (D1) protein of Photosystem II is rapidly cycled under illumination in all oxygenic photobionts (Aro et al., 1993). Disruptions of PsbA cycling or losses of PsbA pools are central to loss of Photosystem II function and consequent photoinhibition of photosynthesis in cyanobacteria, algae and plants under a wide range of conditions including excess light, low temperature and UV exposure (e.g. Bouchard et al., 2002; Campbell et al., 1998). Tracking PsbA pools using the global PsbA antibody elicited by the PsbA peptide sequence tag can show the functional content of Photosystem II in a wide range of samples.
[0037] This PsbA peptide sequence tag is absolutely conserved in the PsbA proteins from almost all known oxygenic photoautotrophs, with only minor variants found in some liverworts. The global antibody raised against this PsbA peptide sequence tag has to date been demonstrated to specifically recognize the PsbA protein from a wide range of species including plants, red algae, cyanobacteria, green algal lichens and a mixed natural phytoplankton community. For example the antibody is being applied to a biological oceanography project to study UV acclimation in natural phytoplankton at sites from the Arctic to the Antarctic (Bouchard et al., 2002), and also to a study of seasonal acclimation in lichens (Schofield et al., 2002).
[0038] 2. RbcL: CLRGGLDFTK DDENINS (SEQ ID NO:2) RbcL (RUBISCO) is the catalytic subunit of the primary carbon dioxide fixation enzyme in the biosphere and is present in all photobionts, along with many other prokaryotic organisms that fix carbon through chemoautotropic mechanisms. The kinetic properties of RbcL are well characterized and the activity of RbcL limits total carbon dioxide uptake by many communities (e.g. Badger & Andrews, 1987; von Cammerer & Quick, 2001). The enzyme has a low turnover rate (low kcat) but because the total flux of carbon fixation through the enzyme is large in photosynthetic organisms, the enzyme accumulates to high concentrations (e.g. 5-10% of extractable protein in cyanobacteria). It is thus a major sink for nitrogen and protein resources in photosynthetic organisms, and is indeed the most abundant protein on earth and a major protein source in the human diet, either directly through consumption of green plants or through contributions to forage feed for animals. Quantitating RbcL thus shows the total capacity for carbon uptake in a sample or community. This RbcL peptide sequence tag is diagnostic of tie Type I sub-class of RUBISCO found in almost all oxygenic photoautotrophic organisms with the exception of dinoflagellates and the marine prochlorophyte Prochlorococcus. This RbcL peptide sequence tag is absolutely conserved in all known sequences from cyanobacteria, green algae, liverworts, mosses, conifers, eudicots, and monocots. The RbcL peptide sequence tag is conserved perfectly in some species, but shows minor variants in some species of ferns, euglenoids, gamma-proteobacteria, beta-proteobacteria, alpha-proteobacteria. It is present but imperfectly conserved in red algae, diatoms, cryptomonads, haptophytes and brown algae. The global antibody raised against this RbcL peptide sequence tag has to date been demonstrated to specifically recognize the RbcL protein from a wide range of species including cyanobacteria, green algal lichens, various plants and a mixed phytoplankton community dominated by diatoms.
IN THE DRAWING
[0039] The accompanying drawing shows the results of an immunoblot chemiluminescent detection of RbcL protein in total protein extracts from (a) an elm tree, (b) cyanobacterium (Synechococcus sp. PCC 7942), (c) marsh grass (Spartina) and (d) mixed population of marine phytoplankton from the Gulf of St. Lawrence, dominated by diatoms.
[0040] Total denatured protein extracts from the four samples were separated by SDS-PAGE and electrophoretically transferred to hydrophobic membrane, The membrane was washed with a 1:4000 dilution of the global RbcL IgY antibody fraction (non-affinity purified) using standard immunoblotting procedures and solutions (Ausubel et al., 1997). The Global RbcL antibody was then detected using a commercial secondary goat anti-chicken IgY antibody conjugated to a horse radish peroxidase enzyme label. Finally, the areas with bound horse radish peroxidase were detected using ECL+(Amersham Pharmacia) chemiluminescent.
[0041] The drawing illustrates the broad detection range and examples of the three main utilities of the new global antibodies raised against peptide sequence tags; namely (a) detection of a major protein from organisms (elm and Spartina) which are relatively uncharacterized at the molecular level but which are of ecological interest, (b) detection of the same protein from a widely studied model species, the cyanobacterium Synechococcus, and (c) detection of the same protein family from a mixed phytoplankton community.
[0042] Application (c) is part of a study of natural phytoplankton responses to changing UVB (Bouchard et al., 2002), where both the absolute level of the target protein and the community structure change under UVB exposure, necessitating an antibody with even detection efficiencies for all members of the target protein family.
[0043] 3. GlnA: cTNSYKLVP G (SEQ ID NO:3) GlnA or glutamine synthetase is the primary point for assimilation of inorganic ammonia nitrogen into the biosphere. During nitrogen assimilation all nitrogen sources are converted to ammonia, no matter what the original source, and then assimilated predominately via the activity of glutamine synthetase. Thus tracking levels of glutamine synthetase shows the metabolic capacity of a sample or community for total nitrogen assimilation.
[0044] This GlnA peptide sequence tag shows perfect to high conservation in alpha, beta and gamma proteobacteria, enterobacteria, most cyanobacteria, thermotogales, low GC gram+, euryarchaeotes and crenarchaeotes. It shows moderate conservation with aquificales, high GC gram+ (Streptomyces) and Trichodesmium thiebautii (a marine cyanobacteria).
[0045] The GlnA peptide sequence tag shows weak and sporadic conservation with glutamine synthetase Type III (GlnN) and with some glutaminyl-tRNA synthetases (glutamine-tRNA ligase) (GLNRS), but antibodies raised against this peptide sequence tag are not expected to detect these enzymes. This peptide sequence tag shows no conservation with any eukaryotic GlnA, and therefore does not react with glutamine synthetases from eukaryotic sources. The global antibody raised against this GlnA peptide sequence tag has to date been demonstrated to specifically recognize the GlnA protein from several species of cyanobacteria.
[0046] 4. NifH: VESGGPEPGV GC (SEQ ID NO: 4) The NifH subunit is a component of the unstable nitrogenase enzyme system responsible for biological fixation of N 2 to assimilable ammonia. Levels of the NifH protein can be used to track the total potential metabolic capacity for nitrogen fixation in any sample or community. This NifH peptide sequence tag is perfectly or near-perfectly conserved in NifH proteins from all known organisms including: alpha, gamma, beta proteobacteria, enterobacteria, cyanobacteria, low GC gram+ bacteria, high GC grant+ bacteria, euryarchaeotes.
[0047] 5. PsaA: cHFSWKMQSD VW (SEQ ID NO 5) PsaA is a core subunit of Photosystem I, a key complex involved in transduction of light to chemical energy in all oxygenic photobionts. Photosystem I participates in both linear and cyclic electron transport in photoautotrophic organisms. The molar ratio between Photosystem II and Photosystem I varies widely between taxa and under different environmental conditions (Falkawski & Raven, 1997), and is an important factor for inferring the acclimation state and photosynthetic performance of an organism or a community. This PsaA peptide sequence tag is specific to the sequence of the PsaA core protein of Photosystem I from all known photoautotrophic organisms, with the exception of a single amino acid mismatch at the third position in the dinoflagellate Heterocapsa triquetra.
[0048] 6. NirB: HWTGCPNSC (SEQ ID NO: 6) NirB or nitrite reductase catalyzes the reduction of nitrite to ammonia, which is an obligatory intermediary step in assimilation of inorganic nitrate into the biosphere. Nitrate is the dominant source of inorganic nitrogen supporting primary productivity in most ecosystems and hence tracking NirB levels show the metabolic capacity for assimilation of this key nitrogen source involved in eutrophication, agricultural run-off and stimulation of algal blooms including harmful (toxic) algal blooms.
[0049] 7. RbcL185: KPKLGLSc (SEQ ID NO: 7) This peptide sequence tag is conserved in both Type I and Type II RbcL and hence can be applied to raise antibodies that will recognize both classes of RUBISCO enzyme, including the RUBISCO found in dinoflagellates and the zooxanthellae symbionts of coral.
[0050] 8. RbcL185 a. KPKLGLSGKN YGRc (SEQ ID NO: 8) This peptide sequence tag is conserved in Type I RUBISCO and could be applied to generate a second anti-RUBISCO antibody for use in ELISA sandwich assays.
[0051] 9. RbcL115: DLFEEGSc (SEQ ID NO: 9) This peptide sequence tag is conserved in Type I RUBISCO and could be applied to generate a second anti-RUBISCO antibody for use in ELISA sandwich assays.
[0052] 10. NarB: IFAEVGRRLG F (SEQ ID NO: 10) This peptide sequence tag is specific to the nitrate reductase (NarB) enzyme from cyanobacteria, a key enzyme in nitrate assimilation.
[0053] 11. NifDMo: VSQSLGHHIA ND (SEQ ID NO: 11) This peptide sequence tag is specific to the NifD subunit of the sub-set of nitrogenases with an iron/molybdenum-based co-factor (as opposed to iron/vanadium or pure iron cofactors).
[0054] 12. NifKMo: CTTCMAEVIG DDL (SEQ ID NO: 12) This peptide sequence tag is specific to the NifK subunit of the sub-set of nitrogenases with an iron/molybdenum-based co-factor (as opposed to iron/vanadium or pure iron cofactors).
[0055] 13. NifKMo: CMAEVIGDDL (SEQ ID NO: 13) This peptide sequence tag is an alternate target specific to the NifK subunit of the sub-set of nitrogenases with an iron/molybdenum-based co-factor (as opposed to iron/vanadium or pure iron cofactors).
[0056] 14. PsbA1: GRQWELc (SEQ ID NO: 14) This peptide sequence tag is specific to cyanobacterial PsbA1, a form of PsbA expressed in acclimated cyanobacteria, but not in eukaryotic photobionts (plants and algae). Monitoring this protein can thus track the contribution of acclimated cyanobacteria to Photosystem II light energy conversion in a mixed community.
[0057] 15. PsbA2 GREWELc (SEQ ID NO: 15) This peptide sequence tag is specific to cyanobacterial PsbA2, a form of PsbA expressed only in cyanobacteria experiencing excitation stress or UVB stress (e.g. Campbell et al., 1998). Monitoring this protein can thus tack when a cyanobacterial population is under excitation or UVB stress. It is also specific to the sole constitutive form of PsbA in eukaryotic photobionts (plants and algae).
[0058] 16. PsaB: FPCDGPGRGG TC (SEQ ID NO: 16) This peptide sequence tag is specific to the PsaB core protein of Photosystem I, a key complex involved in transduction of light to chemical energy in all oxygenic photobionts.
References
[0059] Altschul S et al. (2001) http://www.ncbi.nlm.nih.gov/BLAST
[0060] Aro E M et al. (1993) Biochim Biophys. Acta 1143:113-134
[0061] Ausubel F et al. (1997) Short Protocols in Molecular Biology, Wiley, New York.
[0062] Badger M R, Andrews T J (1987) Progress in Photosynthesis Research Vol. III. Martinus Nijhoff Publishers, pp 601-609.
[0063] Bouchard J N et al. (2002) American Society of Photobiology, Quebec, Canada
[0064] Bryant D (ed,) (1994) The Molecular Biology of Cyanobacteria, Kluwer Academic.
[0065] Campbell D et al. (1998) Proceedings of the National Academy of Sciences of the USA 95:364-369.
[0066] Corpet F (1988) Nucleic Acids Research 16 (22): 10881-10890. http/www.expasy.ch SwissProt public database of annotated protein sequences and accompanying proteomic analysis tools.
[0067] Falkowski P G & Raven J A (1997) Aquatic Photosynthesis. Blackwell Science. http://www.ncbi.nlm.nih.gov Searches for the target protein families show a range of representatives from different taxonomic groups, nonetheless sharing key conserved regions and core biochemical functions.
[0068] Orellana M V & Perry M J (1992) Limnology & Oceanography 478-490
[0069] Schofield S C et al. (2002) in revision.
[0070] Staley J T & Reysenbach A-L (eds.) (2002) Biodiversity of Microbial Life. Wiley-Liss.
[0071] von Caemmerer, S. & Quick, W. P. (2000) In Photosynthesis: Physiology and Metabolism, (ed. R. C. Leegood, T. D. Sharkey, and S. von Caemmerer), Kluwer.
Sequence Listing
[0072] (1) GENERAL INFORMATION
[0073] (i) APPLICANT: Campbell, Douglas A
[0074] (ii) TITLE OF INVENTION: PEPTIDE SEQUENCE TAGS
[0075] (iii) NUMBER OF SEQUENCES: 16
[0076] (iv) CORRESPONDENCE ADDRESS:
[0077] (A) ADDRESSEE: Stikeman, Elliott
[0078] (B) STREET: 1600-50 O'Connor Street
[0079] (C) CITY: Ottawa
[0080] (D) PROVINCE: Ontario
[0081] (E) COUNTRY: Canada
[0082] (F) POSTAL CODE: K1P 6L2
[0083] (v) COMPUTER READABLE FORM:
[0084] (A) MEDIUM TYPE: Floppy disk
[0085] (B) COMPUTER: IBM PC compatible
[0086] (C) OPERATION SYSTEM: PC-DOS/MS-DOS
[0087] (D) SOFTWARE: ASCII
[0088] (vi) CURRENT APPLICATION DATA:
[0089] (A) APPLICATION NUMBER:
[0090] (B) FILING DATE:
[0091] (C) CLASSIFICATION:
[0092] (vii) ATTORNEY/AGENT INFORMATION
[0093] (A) NAME: Derenyi, Eugene
[0094] (B) REGISTRATION NO.:P-52,409
[0095] (C) REFERENCE/DOCKET NUMBER: 105297-1014
1
16
1
15
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
1
Glu Val Met His Glu Arg Asn Ala His Asn Phe Pro Leu Asp Cys
1 5 10 15
2
17
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
2
Cys Leu Arg Gly Gly Leu Asp Phe Thr Lys Asp Asp Glu Asn Ile Asn
1 5 10 15
Ser
3
11
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
3
Cys Thr Asn Ser Tyr Lys Arg Leu Val Pro Gly
1 5 10
4
12
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
4
Val Glu Ser Gly Gly Pro Glu Pro Gly Val Gly Cys
1 5 10
5
12
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
5
Cys His Phe Ser Trp Lys Met Gln Ser Asp Val Trp
1 5 10
6
9
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
6
His Trp Thr Gly Cys Pro Asn Ser Cys
1 5
7
8
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
7
Lys Pro Lys Leu Gly Leu Ser Cys
1 5
8
14
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
8
Lys Pro Lys Leu Gly Leu Ser Gly Lys Asn Tyr Gly Arg Cys
1 5 10
9
8
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
9
Asp Leu Phe Glu Glu Gly Ser Cys
1 5
10
11
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
10
Ile Phe Ala Glu Val Gly Arg Arg Leu Gly Phe
1 5 10
11
12
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
11
Val Ser Gln Ser Leu Gly His His Ile Ala Asn Asp
1 5 10
12
13
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
12
Cys Thr Thr Cys Met Ala Glu Val Ile Gly Asp Asp Leu
1 5 10
13
10
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
13
Cys Met Ala Glu Val Ile Gly Asp Asp Leu
1 5 10
14
7
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
14
Gly Arg Gln Trp Glu Leu Cys
1 5
15
7
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
15
Gly Arg Glu Trp Glu Leu Cys
1 5
16
12
PRT
Artificial Sequence
Description of Artificial Sequence Synthetic
peptide
16
Phe Pro Cys Asp Gly Pro Gly Arg Gly Gly Thr Cys
1 5 10
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Peptide sequence tags are identified and used to produce a class of global antibodies, which recognize all members of a particular protein family with uniform specificity, regardless of the species of origin. The tags are used to create antibodies to the major proteins of photosynthesis, and carbon and nitrogen metabolism. The antibodies have a range of applications as diagnostic detection reagents for major environmental processes.
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This application is a continuation-in-part of application Ser. No. 07/526,662, filed on May 22, 1990, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cryogenic refrigerator and, more particularly, a refrigerator of the refrigerant-accumulating type.
2. Description of the Related Art
Various kinds of cryogenic refrigerators are now on the market. One of them is of the Gifford-McMahon type. This refrigerator is usually arranged as shown in FIG. 1.
The refrigerator comprises generally a cold head 1 and a coolant gas introducing and discharging system 2. The cold head 1 includes a closed cylinder 11, a displacer 12 freely reciprocating in the cylinder 11, and a motor 13 for driving the displacer 11.
The cylinder 11 includes a first large-diameter cylinder 14 and a second small-diameter cylinder 15 coaxially connected to the first cylinder 14. The border wall between the first 14 and the second cylinder 15 forms a first stage 16 as a cooling face and the front wall of the cylinder 15 forms a second stage 17 which is lower in temperature than the first stage 16. The displacer 12 includes a first displacer 18 reciprocating in the first cylinder 14 and a second displacer 19 reciprocating in the second cylinder 15. The first and second displacers 18 and 19 are connected to each other in the axial direction of the cylinder 11 by a connector 20. A fluid passage 21 is formed in the first displacer 18, extending in the axial direction of the displacer 18, and a cooling member 22 formed of copper meshes or the like is housed in the fluid passage 21. Similarly, a fluid passage 23 is formed in the second displacer 19, extending in the axial direction of the displacer 19, and a cooling member 24 formed of lead balls or the like is formed in the fluid passage 23. Seal systems 25 and 26 are located between the outer circumference of the first displacer 18 and the inner circumference of the first cylinder 14 and between the outer circumference of the second displacer 19 and the inner circumference of the second cylinder 15, respectively.
The top of the first displacer 18 is connected to the rotating shaft of the motor 13 through a connector rod 31 and a Scotch yoke or crankshaft 32. When the shaft of the motor 13 is rotated, therefore, the displacer 12 reciprocates, as shown by an arrow 33 in FIG. 1, synchronized with the rotating shaft of the motor 13.
An inlet 34 and an outlet 35 for introducing and discharging coolant gas extend from the upper portion of one side of the first cylinder 14 and are connected to the coolant gas introducing and discharging system 2. The coolant gas introducing and discharging system 2 serves as a helium gas circulating system, comprising connecting the outlet 35 to the inlet 34 through a low-pressure valve 36, a compressor 37 and a high-pressure valve 38. Namely, this system 2 is intended to compress low-pressure (about 5 atm) helium to high-pressure (about 18 atm) helium by the compressor 37 and send it into the cylinder 11. The low- and high-pressure valves 36 and 38 are opened and closed, as will be described later, in a relation to the reciprocation of the displacer 12.
The portions in the refrigerator where cooling is effected or which act as cooling faces are the first and second stages 16 and 17, which are cooled or refrigerated to about 30 K. and 10 K., respectively, when no thermal load is present. Therefore, a temperature gradient ranging from a normal temperature (300 K.) to 30 K. exists between the top and bottom of the first displacer 18 and a temperature gradient ranging from 30 K. to 10 K. exists between the top and bottom of the second displacer 19. These temperature gradients, however, are changed by thermal loads at the step stages and it usually ranges from 30 K. to 80 K. at the first stage 16 while it ranges from 10 K. to 20 K. at the second stage 17.
When the motor 13 starts its rotation, the displacer 12 reciprocates between top and bottom dead centers. When the displacer 12 is at the bottom dead center, the high-pressure valve 38 is opened, allowing high-pressure helium gas to flow into the cold head 1. The displacer 12 then moves to the top dead center. As described above, the seal systems 25 and 26 are arranged between the outer circumference of the first displacer 18 and the inner circumference of the first cylinder 14 and between the outer circumference of the second displacer 19 and the inner circumference of the second cylinder 15, respectively. When the displacer 12 moves to the top dead center, therefore, high-pressure helium gas flows into a first stage expansion chamber 39 formed between the first 18 and the second displacer 19 and then into a second stage expansion chamber 40 formed between the second displacer 19 and the front wall of the second cylinder, passing through the fluid passage 21 in the first displacer 18 and the fluid passage 23 in the second displacer 19. While flowing in this manner, high-pressure helium gas is cooled or refrigerated by the cooling members 22 and 24, so that high-pressure helium gas flowing into the first stage expansion chamber 39 can be cooled to about 30 K. and high-pressure helium gas flowing into the second stage expansion chamber 40 can be cooled to about 8 K. Here, the high-pressure valve 38 is closed and the low-pressure valve 36 is opened. When the low-pressure valve 36 is opened, high-pressure helium gas in the first stage expansion chamber 39 and the second stage expansion chamber 40 is expanded and cooling is effected. The first stage 16 and the second stage 17 are cooled by this cooling phenomenon. Then, the displacer 12 moves to the bottom dead center again and helium gas in the first stage expansion chamber 39 and the second stage expansion chamber 40 is removed as the movement of the displacer 12. The expanded helium gas is warmed by the cooling members 22 and 24 while passing through the fluid passages 21 and 23, and is at an ordinary temperature and discharged. Thereafter, the above-mentioned cycle is repeated and the refrigerating operation is performed. This type of the refrigerator is used for cooling a superconducting magnet or an infrared sensor, or as a cooling source of a cryopump.
However, the above-structured conventional cryogenic refrigerators have the following problems. Specifically, the cylindrical fluid passage 23 is formed in the second displacer 19 and the inside of the passage is filled with the ball or grain-like cooling member 24. Speed distribution in helium gas flowing through the passages which were filled with balls or grains was measured and it was found that velocity of flow was the lowest in the center of the flow of helium gas and that it became higher and higher moving away from the center of the flow of helium gas outward in the radial direction thereof. This means that a larger amount of helium gas flows only into some area of the cooling member 24 and that the cooling member 24 must exchange heat with excessive helium gas at this area thereof when heat exchange is to be done between helium gas and the cooling member 24. This teaches us that the cooling member 24 is not efficiently used. Therefore, cooling efficiency (or heat exchanging efficiency achieved by a cooling means) is reduced at the area of the cooling member, thereby resulting in reducing refrigerating capacity at a certain temperature.
The conventional refrigerators arranged as shown in FIG. 1 have a problem as described below. The seal system 25 prevents helium gas from flowing from the normal temperature section to the first expansion chamber 39 and vice versa, passing through a clearance between the first cylinder 14 and the first displacer 18, while the seal system 26 prevents helium gas from flowing from the first stage expansion chamber 39 to the second stage expansion chamber 40 and vice versa, passing through a clearance between the second cylinder 15 and the second displacer 19. These seal systems 25 and 26 are used in helium gas of high purity (99.99%) and a lubricating material such as grease cannot be used in them because it contaminates helium gas. Particularly the seal system 26 is located at the low temperature section (30 to 80 K.) and has a shape like the piston seal. Providing that the first stage expansion chamber 39 has a temperature of 30 K. while the second stage expansion chamber 40 has a temperature of 10 K. and that helium gas leaks at some portion of the seal system 26, helium gas of 30 K. will enter into the second stage expansion chamber 40 without contacting the cooling member 24 in the second displacer 19 and helium gas of 10 K. will enter into the first stage expansion chamber 39. As the result, the temperature of the first stage 16 falls and that of the second stage 17 rises. FIG. 3 shows, as results calculated, the relation between the ratio of the amount of helium gas leaked through the seal system 26 (or ratio of the amount of helium gas flowing into the second stage expansion chamber 40 through the seal system 26 relative to the total amount of helium gas flowing into the chamber 40 through the passage) and the temperature of each of the first and second stages 16, 17. As apparent from FIG. 3, helium gas leaked at some portion of the seal system 26 adds large influence to the temperature of each of the stages 16 and 17. Same thing can also be said about the seal system 25.
In the conventional refrigerators, the seal system 26 used comprises fitting a turn of sealing 28 provided with overlapped ends 30 as shown in FIG. 6 into a ring-shaped groove 27 on the outer circumference of the second displacer 19 and arranging a spring ring 29 on the backside of the sealing 28 to urge the sealing 28 against the second cylinder 15, as shown in FIGS. 4 through 6. In the case of the seal system 26 having the above-described arrangement, a considerable amount of helium gas is allowed to leak through the overlapped ends 30 of the sealing 28, thereby causing the temperature of the second stage 17 to rise. This results in reducing refrigerating capacity at a certain temperature.
Providing that the temperature of the first stage expansion chamber 39 is 30 K. while that of the second stage expansion chamber 40 is 10 K. and that helium gas leaks through the sealing portion, helium gas of 30 K. will enter into the second stage expansion chamber 40 while helium gas of 10 K. into the first stage expansion chamber 39, without fully contacting the cooling member 24 in the second displacer 19. As a result, the temperature of the first stage 16 lowers while that of the second stage 17 rises. FIG. 7 shows, as results calculated, what relation exists between the ratio of the amount of helium gas leaking through the clearances (or ratio of the amount of helium gas flowing into the second stage expansion chamber 40 through the sealing portion relative to the total amount of helium gas flowing into the chamber 40 through the cooling member) and the temperature of each of the first and second stages 16 and 17. As apparent from FIG. 7, helium gas leaking through the sealing portion between the displacer and the cooling member adds large influence to the temperature of each of the stages.
The conventional refrigerators arranged as shown in FIG. 1 have another problem as described below. When magnetic material is used as a part or whole of the cooling member 24 in the second displacer 19, it is quite difficult to process the magnetic material into balls or meshes such as the cooling member 22 in the first displacer 18. The magnetic material is therefore melted to a bulky mass, which is ground and screened to grains each having a size of about 100 to 500 μm. These grains substantially same in size are used as the cooling member. However, each of these grains has sharp edges and tips which are several μm in size, and these sharp edges and tips are broken off the grains while the refrigerator is under operation. The cooling member 24 is covered by sheets of net at the top and bottom thereof not to drop from the second displacer 19, but these sheets of net have meshes each having a size of several tens μm and fine edges and tips broken off the grains of magnetic material pass through these meshes of the nets together with helium gas. When the meshes of the nets which cover the top and bottom of the cooling member 24 are made smaller in size, however, the pressure loss of helium gas is increased. This is not a merit. The fine edges and tips of magnetic material dropped from the second displacer 19 adhere to the seal 25 to thereby increase the amount of helium gas which leaks through the seal 25. This lowers the refrigerating capacity of the refrigerator to a great extent. In addition, the fine edges and tips of magnetic material dropped come to the compressor 37, passing through the first displacer 18 and the valve 36. As the result, the valve 36 can be blocked and the compressor 37 can be damaged by them. When ground grains of magnetic material are used as the cooling member as described above, the capacity of the refrigerator is lowered and the refrigerator itself is damaged.
The conventional refrigerators arranged as shown in FIG. 1 have a further problem as described below. When the first and second displacers 18 and 19 are filled with the cooling members 22 and 24, clearances are caused between the cooling members and the displacers. When gas flows passing through these clearances, effective heat exchange cannot be carried out between the gas and the cooling member.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a cryogenic refrigerator capable of causing coolant gas to uniformly flow through a cooling member to increase the refrigerating capacity of the refrigerator.
Another object of the present invention is to provide a cryogenic refrigerator capable of enhancing sealing performance between a cylinder and a displacer to increase the refrigerating capacity of the refrigerator.
A further object of the present invention is to provide a cryogenic refrigerator capable of preventing the cooling member from creating fine powder to increase the refrigerating capacity of the refrigerator.
According to the present invention, there is provided a cryogenic refrigerator comprising a closed cylinder provided with an inlet and an outlet for introducing and discharging a coolant gas into and out of the cylinder; a displacer slidably housed in the closed cylinder and housing a cooling member therein and having a passage through which the coolant gas flows; a means coaxially arranged in and along the passage of the displacer in which the cooling member is housed to divide the passage into outer and inner ones; a means for reciprocating the displacer in the cylinder; and a means for repeating the process of introducing the high pressure coolant gas into the cylinder through the inlet and discharging it out of the cylinder, synchronized with the reciprocating displacer.
According to the present invention, there is provided a cryogenic refrigerator comprising a closed cylinder provided with an inlet and an outlet for introducing and discharging a coolant ga into and out of the cylinder; a displacer slidable arranged in the closed cylinder and housing a cooling member therein and having a passage through which the coolant gas flows; plural gas penetrating diaphragms arranged in the passage in which the cooling member is housed and separated from one another by a certain interval in a direction perpendicular to the direction in which the passage is directed; a means for reciprocating the displacer in the cylinder; a means for repeating the process of introducing the coolant ga into the cylinder through the inlet and discharging it out of the cylinder through the outlet in a relation to the reciprocating displacer.
According to the present invention, a cryogenic refrigerator can be provided comprising a closed cylinder provided with an inlet and an outlet for introducing and discharging a coolant gas into and out of the cylinder; a displacer slidably arranged in the closed cylinder and housing a cooling member therein and having a passage through which the coolant gas flows; plural gas penetrating diaphragms arranged in the passage in which the cooling member is housed and separated from one another by a certain interval in a direction perpendicular to the direction in which the passage is directed; a means for reciprocating the displacer in the cylinder; a means for repeating the process of introducing the high pressure coolant gas into the cylinder through the inlet and discharging it out of the cylinder through the outlet in a relation to the reciprocating displacer and first and second sealing members arranged along the axis of the displacer to seal the clearance between the closed cylinder and the displacer; wherein said displacer has two ring-shaped grooves on the outer circumference thereof and each of the sealing members includes two sealing rings each having both ends and piled one upon the other in the ring-shaped groove in the axial direction of the displacer and a spring ring having both ends and located on the back side of these sealing rings.
According to the present invention, a cryogenic refrigerator can be provided comprising a closed cylinder provided with an inlet and an outlet for introducing and discharging a coolant gas into and out of the cylinder; a displacer slidably arranged in the closed cylinder and housing a cooling member therein and having a passage through which the coolant gas flows; a means for reciprocating the displacer; and a means for repeating the process of introducing the coolant gas into the cylinder through the inlet and discharging it out of the cylinder through the outlet in a relation to the reciprocating displacer; wherein said cooling member is those grains of a magnetic matter which are coated by a metal film.
According to the present invention, a cryogenic refrigerator can be provided comprising a closed cylinder provided with an inlet and an outlet for introducing and discharging a coolant gas into and out of the cylinder; a displacer slidably arranged in the closed cylinder and housing a cooling member therein and having a passage through which the coolant gas flows: a fibrous member arranged between the displacer and the cooling member; a means for reciprocating the displacer; and a means for repeating the process of introducing the high pressure coolant gas into the cylinder through the inlet and discharging it out of the cylinder through the outlet in a relation to the reciprocating displacer.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a cross sectional view showing a conventional Gifford-McMahon type cryogenic refrigerator;
FIG. 2 is a cross sectional view showing a second displacer of the refrigerator of FIG. 1;
FIG. 3 is a graph showing the relationship between a rate of leakage and temperature of stages in a sealing mechanism of the refrigerator of FIG. 1;
FIGS. 4 to 6 are cross sectional views showing the sealing mechanism of the refrigerator of FIG. 1;
FIG. 7 is a graph showing the relationship of a rate of leakage and temperature of stages between a second displacer and a cooling member of the refrigerator of FIG. 1;
FIG. 8 is a cross sectional view showing a Gifford-McMahon type cryogenic refrigerator relating to one embodiment of the present invention;
FIG. 9 is a cross sectional view showing a second displacer of the refrigerator of FIG. 8;
FIG. 10 is a graph showing the comparison between the speed distribution in helium gas in the cooling member of the second displacer of the refrigerator of FIG. 1 and that of the second displacer of the refrigerator of FIG. 8;
FIG. 11 is a graph showing the comparison between the cooling curve of the refrigerator of FIG. 1 and that of the refrigerator of FIG. 8;
FIG. 12 is a cross sectional view showing a Gifford-McMahon type cryogenic refrigerator relating to a second embodiment of the present invention;
FIG. 13 is a sectional view showing a second displacer of the refrigerator of FIG. 12;
FIG. 14 is a graph showing the comparison between the speed distribution in helium gas in the cooling member of the second displacer of the refrigerator of FIG. 1 and that of the second displacer of the refrigerator of FIG. 12;
FIG. 15 is a cross sectional view showing a Gifford-McMahon type cryogenic refrigerator relating to a third embodiment of the present invention;
FIG. 16 is a cross sectional view showing a second displacer of the refrigerator of FIG. 15;
FIG. 17 is a graph showing the comparison between the speed distribution in helium gas in the cooling member of the second displacer of the refrigerator of FIG. 1 and that of the second displacer of the refrigerator of FIG. 15;
FIG. 18 is a cross sectional view showing a Gifford-McMahon type cryogenic refrigerator relating to a fourth embodiment of the present invention;
FIGS. 19 to 21 are cross sectional views showing a sealing mechanism of the refrigerator of FIG. 18;
FIG. 22 is a graph showing the relationship between leakage of helium and difference in pressure in the refrigerator, in which the sealing mechanism of FIG. 5 is incorporated, and the refrigerator, in which the sealing mechanism of FIG. 21 is incorporated;
FIG. 23 is a graph showing the cooling curves of the refrigerator, in which the sealing mechanism of FIG. 5 is incorporated, and the refrigerator, in which the sealing mechanism of FIG. 20 is incorporated;
FIG. 24 is a cross sectional view showing a Gifford-McMahon type cryogenic refrigerator relating to a fifth embodiment of the present invention;
FIG. 25 is a view showing a magnetic member using as a cooling member of the cryogenic refrigerator;
FIGS. 26A and 26B are views showing the state that the magnetic member of FIG. 25 is plated with metal;
FIG. 27 is a graph showing the cooling curves of the refrigerator in which the magnetic member of FIG. 25 is incorporated, and the refrigerator in which the magnetic member of FIGS. 26A and 26B is incorporated; and
FIG. 28 is a view showing the magnetic member after mixing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Some preferred embodiments of the present invention will be described in detail.
FIG. 8 is a sectional view showing an example of the Gifford-McMahon type refrigerator, which is same in arrangement as the one shown in FIG. 1 except a fluid path or passage 123.
The refrigerator includes generally a cold head 101 and a coolant gas introducing and discharging system 102. The cold head 101 comprises a closed cylinder 111, a displacer 112 housed in the cylinder 111 and freely reciprocating therein, and a motor 113 for driving the displacer 112 to reciprocate in the cylinder 111.
The cylinder 111 includes a first large-diameter cylinder 114 and a second small-diameter cylinder 115 coaxially connected to the cylinder 114. The border wall between the first cylinder 114 and the second cylinder 115 forms a first stage 116 which serves as a cooling face, and the front wall of the cylinder 115 forms a second stage 117 which is lower in temperature than the first stage 116. The displacer 112 includes a first displacer 118 reciprocating in the first cylinder 114 and a second displacer 119 reciprocating in the second cylinder 115. The first and second displacers 118 and 119 are connected to each other by a connector member 120 in the axial direction of the cylinder 112. A fluid passage 121 is formed in the first displacer 118, extending in the axial direction of the displacer 118, and a cooling member 122 made by copper meshes or the like is contained in the fluid passage 121. Similarly, a fluid passage 123 is also formed in the second displacer 119, extending in the axial direction of the displacer 119, and a cooling member 124 made by copper balls or the like is contained in the fluid passage 123. Seal systems 125 and 126 are located between the outer circumference of the first displacer 118 and the inner circumference of the first cylinder 114 and between the outer circumference of the second displacer 119 and the inner circumference of the second cylinder 115, respectively.
The top of the first displacer 118 is connected to the rotating shaft of the motor 113 through a connector rod 131 and a Scotch yoke or crankshaft 132. When the shaft of the motor 113 is rotated, therefore, the displacer 112 is reciprocated as shown by an arrow 133 in FIG. 8, synchronized with the rotating shaft of the motor 113.
An inlet 134 and an outlet 135 for coolant gas extend outwards from the upper portion of one side of the first cylinder 114 and are connected to the coolant gas introducing and discharging system 102. This system 102 serves to circulate helium gas flowing through the cylinder 111 and includes a compressor 137 connected to the outlet 135 to the inlet 134 through a low-pressure valve 136 and a high-pressure valve 138. The system 102 also serves to compress low pressure helium gas (about 5 atm) to high pressure one (about 18 atm) through the compressor 137, sending the compressed helium into the cylinder 111. The low- and high-pressure valves 136 and 138 are opened and closed in a relation to the reciprocating displacer 112.
As shown in FIG. 9, a pipe 142 is coaxially housed in the fluid passage 123 and allows helium ga to flow inside and outside the pipe 142. A fluid passage 143 inside the pipe 142 is filled with a cooling member 145 shaped like balls each having a diameter of 0.4 mm and another fluid passage 144 outside the pipe 142 is filled with a cooling member 146 shaped like balls each having a diameter of 0.2 mm.
The passage of helium gas is divided into two in the same direction as helium gas flows, and the large-diameter cooling balls 145 are housed in the inner fluid passage 143. This reduces the pressure loss of helium gas flowing through the inner fluid passage 143 and the amount of helium gas flowing through the passage 143 is increased accordingly. The partial flow of helium gas can be thus reduced to a greater extent. This enables the cooling efficiencies of the cooling balls 145 and 146 to be increased so as to enhance the refrigerating capacity of the refrigerator.
FIG. 10 shows results obtained by measuring the flow speed distributions of helium gas flowing through the cooling members in the fluid passages shown in FIGS. 2 and 9. These results were obtained under normal temperature and with the refrigerators kept static, providing that the outer diameters of the fluid passages, the amounts of the cooling members contained in the fluid passages and the materials by which the cooling members are made are same. These conditions are different from those (cryogenic temperature and reciprocating motion) under which the refrigerators are practically operated, but it is understood that the flow speed distribution of helium gas flowing through the cooling member in the fluid passage shown in FIG. 9 is more uniform. It is supposed that this trend can be kept under the practical conditions. FIG. 11 shows refrigerating curves achieved by the conventional cryogenic refrigerator in which the fluid passage 23 shown in FIG. 2 is incorporated and by the cryogenic refrigerator of the present invention in which the fluid passage 123 shown in FIG. 9 is incorporated. The horizontal axis of the coordinate shown in FIG. 11 represents temperatures (K.) of the second stage 117 and the vertical axis thereof heat loads (W) added to the second stage 117. As apparent from FIG. 11, refrigerating capacity under same temperature is higher in the case of the cryogenic refrigerator according to the present invention. It is therefore understood that refrigerating capacity can be increased when the fluid passage 123 which has the above-described arrangement is employed. Although the fluid passage in this example is divided into two concentric ones, it may be divided into three or more ones. The diameter of the ball is not limited to 0.4 mm or 0.2 mm.
FIGS. 12 and 13 show a second example of the cryogenic refrigerator according to the present invention, in which the pipe 142 is coaxially housed in the fluid passage 141, the passage of helium gas is divided to flow inside and outside the pipe 142, and a cooling member 124 contained in the inner and outer passages 143 and 144 is shaped like balls each having same size. The passage of helium gas is divided into two in same direction as helium gas flows, so that the partial flow of helium gas can be reduced to a greater extent, as compared with that in the conventional case. Therefore, cooling efficiency achieved by the cooling member 124 can be increased to thereby enhance the refrigerating capacity of the refrigerator.
FIG. 14 shows results obtained by measuring the flow speed distributions of helium gas flowing through the cooling members contained in the fluid passages shown in FIGS. 2 and 13. These results were obtained under normal temperature and with the refrigerators kept static, providing that the outer diameters of the fluid passages, the amounts, shapes and sizes of the cooling members contained in the fluid passages, and the materials by which the cooling members are made are the same. These conditions are different from those (cryogenic temperature and reciprocating motion) under which the refrigerators are practically operated but it is understood that the flow speed distribution of helium gas flowing through the cooling member in the fluid passage shown in FIG. 13 is more uniform. It is supposed that this trend can be kept under the practical conditions. Although the fluid passage in this example is divided into two concentric ones, it may be divided into three or more ones. They may be neither concentric nor cylindrical.
FIG. 15 shows a third example of the cryogenic refrigerator according to the present invention.
This third example is different from the first example in the arrangement of a fluid passage 141 which is formed in the second displacer 119 and in which the cooling member 124 is contained.
As shown in FIG. 16, the cooling member 124 shaped like balls, and sheets of meshes 147 are contained in the fluid passage 141 in such a way that they are alternately piled in the fluid passage 141 in direction perpendicular to the flow of helium gas.
When the fluid passage 141 is arranged in this manner, helium gas flowing through the passage 141 can be made uniform by the sheets of meshes. The partial flow of helium gas can be thus reduced to a greater extent, as compared with that in the conventional case. Therefore, cooling efficiency achieved by the cooling member 124 can be increased so as to enhance the refrigerating capacity of the refrigerator.
FIG. 17 shows results obtained by measuring the flow speed distributions of helium gas flowing through the cooling members in the fluid passages shown in FIGS. 2 and 16. These results were measured under normal temperature and with the refrigerators kept static, providing that the outer diameters of the fluid passages, the amounts, shapes and sizes of the cooling members and the materials by which the cooling members are made are same. These conditions are different from those (cryogenic temperature and reciprocating motion) under which the refrigerators are practically operated, but it is understood that the flow speed distribution of helium gas flowing through the fluid passage shown in FIG. 16 is more uniform. It is supposed that this trend can be kept under the practical conditions. Glass wool or the like may be used as spacers instead of the sheets of meshes.
Although the fluid passage in the second displacer has been arranged as shown in FIGS. 9, 13 and 16 in the case of the above-described three examples, the fluid passage in the first displacer may be arranged as shown in FIGS. 9, 13 and 16. These arrangements of the fluid passage can be applied to the cryogenic refrigerator which includes third and fourth displacers. The fluid passage in which the cooling member is housed may be arranged as shown in FIGS. 9, 13 and 16 even in the case of those cryogenic refrigerators in which the displacers and the cooling accumulator are not combined as a unit.
FIG. 18 shows a fourth example of the cryogenic refrigerator according to the present invention. Same components as those in the first example shown in FIG. 8 will be represented by same reference numerals and description on these components will be omitted.
This example is different from the conventional cryogenic refrigerators by seal systems 151 and 155 which are fitted into ring-shaped grooves 127 and 128 on the outer circumference of the second displacer 119 to seal the clearance between the second displacer 119 and the second cylinder 115.
As shown in FIGS. 19 and 20, the seal system 151 includes an outer ring 152 having both ends, an inner ring 153 located on the backside of the outer ring 152, and a spring ring 154 coaxially located on the backside of the inner ring 153 to urge the ring 153 against the inner circumference of the second cylinder 115, these rings being fitted in the ring-shaped groove 127. The outer and inner rings 152 and 153 are made of resin. As shown in FIG. 20, the section of the inner ring 153 is shaped like a fallen L and the section of the outer ring 152 is a rectangle seated on the L-shaped section of the inner ring 153. The clearance between both ends of the outer ring 152 is shifted from that between both ends of the inner ring 153 by 180°. When both of the outer and inner rings 152 and 153 are combined with each other in this manner, the outer circumferences of the outer and inner rings 152 and 153 are contacted with the inner circumference of the second cylinder 115 while keeping two inner sides of the inner ring 153 contacted with two outer sides of the outer ring 152. As shown in FIG. 21, the sections of the outer and inner rings 152 and 153 in the seal system 151 are symmetrical with respect to the axis of the second cylinder 115 relative to those of the outer and inner rings 156 and 157 in the seal system 155. When the clearances in the seal system 151 are shifted from those in the seal system 155 in the circumferential direction of the second cylinder 115, therefore, helium gas can be prevented from leaking through these clearances. The leakage of helium gas can be thus reduced to a greater extent by these seal systems 151 and 155. The temperature of the second expansion chamber or second stage 117 can be prevented from rising to thereby enhance the refrigerating capacity of the refrigerator.
FIG. 22 shows results obtained by measuring the amounts of helium gas leaking through the conventional cryogenic refrigerator into which the seal system shown in FIG. 5 is incorporated and through the cryogenic GM refrigerator into which the seal systems 151 and 155 are incorporated. These results were measured under normal temperature and with the refrigerators kept static, providing that the widths of the ring-shaped grooves are made equal, that the shapes of the seal rings are same and that the materials by which the seal rings are made are same. These conditions are different from those (cryogenic temperature and reciprocating motion) under which the refrigerators are practically operated, but it is understood that the amount of helium gas leaked can be reduced to a considerable extent. It is supposed that this trend will be kept under practical conditions. FIG. 23 shows refrigerating curves achieved by the conventional cryogenic refrigerator into which the seal system shown in FIG. 5 is incorporated and by the cryogenic refrigerator of the present invention into which the seal systems 151 and 155 shown in FIG. 21 are incorporated. The horizontal axis of the coordinate shown in FIG. 23 represents temperatures (K.) of the second stage 117 and the vertical axis thereof denotes heat loads (W) added to the second stage 117. As apparent from FIG. 23, refrigerating capacity under same temperature is higher in the case of the cryogenic refrigerator according to the present invention. This teaches us that the refrigerating capacity can be increased when the seal systems 151 and 155 are employed.
Although the seal systems 151 and 155 have been arranged only between the second displacer and the second cylinder in the case of the above-described example, they may be arranged between the first displacer and the first cylinder.
FIG. 24 shows a fifth example of the cryogenic refrigerator according to the present invention. Same components as those in the example shown in FIG. 8 will be represented by same reference numerals and description on these components will be omitted.
When the first and second displacers 118 and 119 are to be filled with the cooling members 122 and 124 shaped like copper sheets of meshes and lead balls, a filler 167 is previously arranged along the inner walls of the first and second displacers 118 and 119 and the cooling members 122 and 124 are then housed inside the fillers 167 in the displacers 118 and 119. The filler 167 is cotton wool made of glass, metal, ceramic and other artificial inorganic fibers.
When clearances 148 between the inner wall of the first displacer 118 and the cooling member 122 and between the inner wall of the second displacer 119 and the cooling member 124 are filled with the fillers 167, the leakage of gas can be prevented to effectively carry out heat exchange between the cooling members 122 and 124 and the gas.
Sixth and seventh examples of the invention will be explained.
The refrigerators according to these embodiments are distinguished from the conventional one by a magnetic material used as the cooling member 124 contained in the displacer 119. The magnetic material contains a rare earth metal, such as La, Ce, Pr, Nd, Eu, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Y, and is generally friable. The magnetic material may include Er 3 Ni, GdRh, RNi 2 (R: Dy, Ho, Er), A 1-x B x Rh i-y x y (A: Sm, Tb, Dy; B: Ho, Er, Tm, Yb; X: Cu, Zn, Ru, Pd, Ag, Re, Os, Ir, Pt, Au; 0≦×≦1, 0≦y<0.2), or the like.
The magnetic material is obtained by melting a row material, then breaking a resultant lump, and selecting particles of e.g. 100-500 μm by use of a screen. FIG. 25 shows the magnetic material thus obtained. As is shown in FIG. 25, the magnetic material M has a number of small edges 171 each having a height of several μm--several tens of μm and an angle of 30° or less. If the magnetic material is used as the cooling member, edges thereof may be broken into fine particles during a long time period of operation, thereby causing the fine particles to leak from the cooling accumulator into the refrigerator. The amount of the magnetic material lost will reach 2-3 weight %.
Two method can solve the problem, ,one being plating the magnetic particles, thereby coating their edges with metal films, and the other being removing the edges by mixing.
First, the sixth example directed to the method for coating the edges of each magnetic particle with a metal film will be explained.
It is preferable that this metal is more excellent in toughness than the magnetic material M, that its thermal conductivity is substantially same as that of the magnetic material M and that it can be more easily processed to coat the grain of the magnetic material M. Gold, silver, copper, nickel, chrome, aluminum, lead and molybdenum, for example, can be used as the metal film S. An alloy of these metals may be used, too. The metal film S is formed according to the plating or depositing manner. It is preferable that the metal film S has a thickness of several μm to several tens of μm.
FIG. 26A shows a grain of the magnetic material M which is obtained after the plating process. As seen in FIG. 26B, the sharp edge or tip 171 of the grain is coated by the plating metal S and when these grains of the magnetic material M are used as the cooling member, fine powder of the magnetic material M can be prevented from dropping from the second displacer 119 and adhering to the seal systems and the like to lower the refrigerating capacity of the refrigerator. This is because the sharp edges or tips 171 of the grain are fixed and rounded by the metal film S and because the metal film S serves as a lubricating layer or cushion to prevent stress from being added to the edges or tips 171 of the grain. The sharp edges or tips 171 can be thus prevented from breaking off from the grain of the magnetic material M.
FIG. 27 shows refrigerating curves achieved by the cryogenic refrigerator in which grains obtained by grinding the magnetic material M were used as the cooling member, and by the one in which grains obtained by grinding the magnetic material M were plated and then used as the cooling member. These refrigerating curves were obtained after the lapse of 100 hours since the refrigerators were under operation. The horizontal axis of a graph shown in FIG. 27 denotes temperatures (K.) of the second stage 117 and the vertical axis thereof represents heat loads (W) added to the second stage 117. The refrigerating curves were overlapped with each other just after the refrigerators were started, but they showed a difference in the refrigerating capacities of the two refrigerators after the lapse of 100 hours. The refrigerator in which plated grains of the magnetic material M were used as the cooling member showed same refrigerating capacity as that just after the start of its operation. After the refrigerating curves were obtained, both of the refrigerators were dismantled and examined. Fine powder of the magnetic material M adhered to the seal 126 in the case of the refrigerator in which grains of the magnetic material M obtained by grinding the material M were used as the cooling member, but no fine powder could be found in the case of the refrigerator in which grains of the magnetic material M were plated and then used as the cooling member. It is therefore supposed that fine powder of the magnetic material M which adhered to the seal causes the amount of gas leaked through the seal 126 to be increased to thereby lower the refrigerating capacity of the refrigerator, as seen in FIG. 27. This makes it apparent that the use of plated grains of the magnetic material M as the cooling member is more effective.
Next, the seventh example directed to the method for mixing magnetic particles will be explained.
As is mentioned above, the magnetic material M has a plurality of edges 171 each having a height of several μm to several tens of μm and an angle of 30° or less. If the magnetic material is used as the cooling member, edges thereof may be broken into fine particles during a long time period of operation, thereby causing the fine particles to leak from the cooling accumulator to the refrigerator. To avoid this, a magnetic material having no edges 171 of an angle 30° or less is used as the cooling member.
Such appropriate magnetic material can be obtained by melting a row material, breaking a resultant lump, selecting bodies of an appropriate size, and mixing them in an organic solvent containing no water or in an atmosphere containing no oxygen, nitrogen, or hydrogen. The reason why an organic solvent without water is used is that it is necessary to remove heat caused during mixing.
Further, the reason why the mixing is performed in an organic solvent containing no water or in an atmosphere containing no oxygen, nitrogen, or hydrogen is that the magnetic material containing a rare earth metal may deteriorate in a solvent containing water or in the atmosphere of oxygen, nitrogen, or hydrogen, thereby not only losing a function as the cooling member, but also causing fine particles which may choke a pipe or the like. Preferably, acetone or alcohol is used as the organic solvent. The alcohol is selected from the group consisting of methyl alcohol, ethyl alcohol, propyl alcohol, and buchyl alcohol.
In the case of using an organic solvent, the magnetic material and solvent are preferably in the ratio from 1:1 to 10:1. In the case of using a gas as a mixing atmosphere, the gas is preferably an inactive gas such as argon. In both cases, mixing can be performed at a room temperature. It is desirable to perform mixing by use of a ball mill without balls or a vibrating mill without balls. It is most desirable to use a planetary ball mill.
24-hour mixing was conducted using a planetary ball mill (Pulverisette III), 200 g of Er 0 .5 Dy 0 .5 Ni 2 as the magnetic material, and 100 g of acetone as the organic solvent.
FIG. 28 shows a grain of the magnetic material M obtained after the mixing process. As seen in FIG. 28, sharp edges or tips are removed from the grain by the mixing process. When these grains of the magnetic material M are used as the cooling member, it can be prevented that the sharp edges or tips are broken off from the grains of the magnetic material M and dropped, as fine powder, from the second displacer 119 into the refrigerator, while the refrigerator is being operated, to adhere to the seal and the like and lower the refrigerating capacity of the refrigerator.
Same refrigerating capacity test as that in the sixth example was conducted using the grains of the magnetic material M as the cooling member. Same results as those shown in FIG. 27 were obtained. Further, the refrigerators were dismantled and examined after the test and similar results as found in the sixth example were discovered.
Although description has been made about those refrigerators in which the displacer and the cooling accumulator are combined with each other as a unit, the present invention can be applied to the other refrigerators in which the displacer and the cooling accumulator are not combined as a unit.
Further, description has been made about the refrigerator of the Gifford-McMahon type which is typical of the cryogenic refrigerators, but the present invention can be applied to the other cryogenic refrigerators of the improved Solvay, Stirling and cycle types.
Still further, the magnetic material may be shaped like grains, powder and fabrics (such as the sheet of meshes). It may also be made porous.
The magnetic material may include Er 3 Ni, ErNi 2 , GdRh or the like.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices, and illustrated examples shown and described. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
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A cryogenic refrigerator comprising a closed cylinder provided with an inlet and an outlet for introducing and discharging a coolant gas into and out of the cylinder, a displacer slidably housed in the closed cylinder and housing a cooling member therein and having a passage through which the coolant gas flows, a device coaxially arranged in and along the passage of the displacer in which the cooling member is housed to divide the passage into outer and inner ones, a device for reciprocating the displacer in the cylinder, and a device for repeating the process of introducing the high pressure coolant gas into the cylinder through the inlet and discharging it out of the cylinder, synchronizing with the reciprocating displacer.
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FIELD OF THE INVENTION
The present invention relates to an automobile antitheft device, and more particularly to a device for attachment to an automobile steering wheel to prevent complete rotation of the wheel and securing the automobile against unauthorized driving.
BACKGROUND OF THE INVENTION
Antitheft devices which attach to an automobile steering wheel have been known heretofore, as shown by U.S. Pat. No. 4,738,127 to Johnson. Such antitheft device for attachment to a steering wheel of an automobile includes an elongated body member having a passage way extending along an axis therethrough, an elongated rod member adapted to move in telescopic fashion in the passage way of the body member along the axis, opposed hooks for engaging inside portions of the steering wheel and lock means associated with the body member engaging the rod within the passage way for locking the rod within the passage and stationary with respect to the body member at any of selectable a plurality of positions. While the antitheft device described above is functional, it includes several disadvantages. For example, such device presents pry points wherein a rigid pin or arcuate ruler-like thin objects can be inserted through a gap between the passage and periphery of the rod member to reach a spherical bearing of the lock means and further press it down by overcoming the bias force of a spring member thereon to release it from engaging the rod member in a groove thereof and thereby unlock the device.
SUMMARY OF THE INVENTION
It is accordingly a primary object of this invention to provide an automobile steering lock that overcomes the foregoing disadvantages associated with prior art devices.
Another object of this invention is to provide a locking device wherein the locking mechanism is totally enclosed therein and includes no area susceptible to prying by a crowbar, rigid pin or the like.
A yet further object of this invention is to provide an automobile steering lock having a mechanism for preventing a rod member thereof from being released therefrom.
A further object of this invention is to provide an automobile steering lock which is simple in construction, economical in manufacture and easy in assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective and exploded view of a preferred embodiment of the present invention;
FIG. 2 is a partially broken perspective view of the preferred embodiment in an assembled condition;
FIG. 3 is an enlarged cross-sectional view taken at an end portion of a body member of the preferred embodiment;
FIG. 4 is an enlarged transverse-sectional view taken at an end portion of the body member;
FIG. 5 is a perspective view of the preferred embodiment in an assembled condition;
FIG. 6 is a cross-sectional view of a housing means of the preferred embodiment, shown in a locking condition, and illustrating tenon ends of a pair of rod-like bearings protruding into annular grooves respectively formed in rod members;
FIG. 7 is a cross-sectional view of the housing means of the preferred embodiment, shown in an unlocking condition, and illustrating the tenon ends of the rod-like bearings withdrawn from the annular grooves of the rod members; and
FIG. 8 is a diagramatic perspective view showing the steering lock of the present invention locking the steering wheel of a car.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, an automobile steering lock according to the present invention comprises an elongated body member 2, which is constituted by two identical elongated tubes 20, 21 of square cross section disposed parallel to end adjacent each other, a first elongated rod member 3 and a second elongated rod member 4 which are dimensioned to move in telescopic fashion within body member 2, first and second hooks 201, 30 for engaging opposed portions of a steering wheel from the inside thereof, being respectively provided on the body member 2 and first rod member 3, a housing 22, and a locking means including a conventional key lock 71, a locking member 70 and a pair of locating means 80, 81 being provided within housing 22 to position and lock rod members 3, 4 stationary with respect to the body member 2 at any one of selectable a plurality of positions.
As described above, the body member 2 includes two identical elongated steel tubes 20, 21 of square cross-section having open ends and closed ends and defining respective central passages running from the open ends to the closed ends. The two tubes 20, 21 are firmly joined together by means of end retainers 23, 24 and welding. Each of the end retainers 23, 24 is formed with a square opening for firmly receiving a tube and a circular opening 210 or 200 communicating the central passage of another tube of which the open end is attached with the end retainer. Openings 200, 210 of the tubes 20, 21 of the body member 2 face opposite in direction so that the first and second rod members 3, 4 telescope in opposite directions with respect to each other from the body member 2.
The first hook 201 is generally an L-shaped member fixedly secured to the tube 20 by means of welding and opens rearwardly along the body member 2 for engagement with a first inside portion of a steering wheel. Said first rod member 3 includes an elongated rod 3 of circular cross-section of which the outer diameter is dimensioned less than the diameter of the first passage in the first tube 20 of the body member 2 and slightly less than the diameter of the circular opening 200 of the end retainer 24 to enable first rod member 3 to telescope freely within the first tube 20. The second hook so is generally an L-shaped member fixedly secured to the front end portion of the first rod member 3 and opens opposite to the hook 201 for engagement with a diametrically opposed second inside portion of a steering wheel, as best shown in FIG. 8. A plurality of annular grooves 31 are longitudinally spaced along a major portion of the first rod member 3. Each of the grooves 31 consists of a vertical side wall 311 substantially perpendicular to the longitudinal axis of first rod 3 and disposed closer to the second hook 30, and a conical or sloping side wall 310 disposed farther from the second hook 30. A cylindrical projection 32 is attached to the end opposite to the hooked end 30 of the first rod 3 and is formed with a radial key hole 320. A guide body 5 of oval shape having a central hole 50 is provided for sleeving around the cylindrical projection 32 and being secured in position by means of a key N1 press-fitted into aligned key holes 51, 320 in the guide body 5 and the projection 32.
Said second rod member 4 is an elongated rod of circular cross-section of which the diameter is dimensioned less than the diameter of the second passage in the second tube 21 of the body member 2 and slightly less than the diameter of the circular opening 210 of the end retainer 23 to enable second rod member 4 to telescope freely within the second tube 21. A handle 43 is secured to the free end of the second rod 4. A plurality of annular grooves 40 are identical to yet reversely arranged with respect to the grooves 31 of the first rod 3, and are longitudinally spaced along a major portion of the second rod member 4. Each of the grooves 40 consists of a vertical side wall 401 substantially perpendicular to the longitudinal axis of the second rod 4 and disposed closer to the handle end 43 and a conical or sloping side wall 400 disposed farther from the handle end 43. A cylindrical projection 42 extending axially is attached to the end opposed to the handle end 43 of the second rod 4 and is formed with a radial key hole 420. A guide body 6 of oval shape having a central hole 60 is provided for sleeving around the cylindrical projection 42 and being secured in position by means of a key N2 press-fitted into aligned key holes 61, 420 in the guide body 6 and projection 42.
The housing 22 includes a boss 222 integrally offset with respect to parallel axes of the central passages in the elongated tubes 20, 21 of the body member 2 and having a bore 221 therethrough into the housing 22 for firmly receiving the locking means which has the conventional key lock 71, projection 710 integrally attached to the inner end of the cylindrical key lock 71, locking member 70 and locating means 80, 81.
As shown in FIGS. 6 and 7, in order to accommodate the locating means 80, 81 a second pair of passages 805, 815 are vertically bored in the lower portion of the housing 22. Said vertical passages 805, 815 interconnect the bore 221 and the respective passages in the elongated tubes 20, 21. A rectangular opening 220, in vertical alignment with the vertical passages 805, 815, is formed in an upper wall of the housing 22 to facilitate inserting the locating means 80, 81. A metal plate 9 is provided to close off opening 220 by means of a press fit after assembly.
As shown in FIGS. 3 and 4, due to confinement of circular opening 200 or 210 on the open end of the tube 20 or 21, the guide body 5 or 6 secured to inner end of the rod member 3 or 4 by means of the key N1 or N2 press-fitted into aligned key holes in the guide body 5 or 6 and cylindrical rear projection 32 or 42 of the rod member 3 or 4 allows the rod member 3 or 4 to telescope in the central passage in the tube 20 or 21 and prevents the rod member 3 or 4 from being released from the tube 20 or 21.
The locking member 70 is a substantially semicircular segment in cross-section and includes an arcuate outer surface, which conforms to the bone 221 in circular inner surface of the housing 22, and a flat top. A recess 701 is formed in a side wall adjacent the key lock 71 and a post 700 serving as an axle of the locking member is formed in an opposite side wall of the locking member 70 to pivotally mounting the locking member 70 in the bore 221 of the housing 22, and two axially spaced-apart notches 702, 703 formed in one side of the locking member 70.
The locating means include two rod-like bearings 80, 81 having projections 800, 810 on the top ends thereof for receiving the lower ends of biasing springs 82, 83, tenon ends defined with vertical side walls 803, 813 and slanting bottoms 804, 814, which are reversely arranged with respect to each other, and extending downwardly towards the passages in the tubes 20, 21, and laterally opposed pivots 801, 802, 811, 812. The upper ends of the biasing springs 82, 83 abut against the inner side wall of the metal plate 9 when the device is in assembled condition.
In assembly, as shown in FIGS. 2 to 7, the rod-like bearings 80, 81 are inserted into the vertical passages 805, 815 through the opening 220 and the cylindrical key lock 71 is firmly received in the bore 221 with the projection 710 thereof fitted in the recess 701 of the locking member 70 such that the locking member 70 is disposed within the bore 221 with the notches 702, 703 thereof vertically in alignment with the vertical passages 805, 815 and opening 220 to support pivots 801,802, 811, 812 of the rod-like bearings which extend downwardly through the notches 702, 703 and is operable to slide or swing along the circumferential inner surface of the bore 221 by means of the projection 710. The springs 82, 83 are mounted on the tops of the rod-like bearings 80, 81 and disposed in compressed state when the metal plate 9 closes off the opening 220.
In operation, as shown in FIG. 6, the rod-like bearings 80, 81 are biased downwardly by the compressed springs 82, 83 towards respective rods 3, 4 whereas the tenon ends of the rod-like bearings 80, 81 locate in a first position where the flat top of the locking member 70 slants downwardly towards the notched side thereof and protrude into grooves 31, 40 to lock the device. Although in locking condition, the convex or slope side walls 310, 400 of the grooves 31, 40 of the first and second rods 3, 4 allow the rod members 3, 4 of this antitheft device to extend in telescopic fashion with respect to the body member 2 in opposite directions with respect to each other by overcoming biasing forces of the spring members 82, 83. However, the vertical side wall 311 of the first rod member 3 and the vertical side wall 401 of the second rod member 4 abutting the vertical surfaces 803, 813 of the tenon ends of the rod-like bearings 80, 81, prohibit the rod members 3, 4 from retracting back into the body member 2. By so doing, as in locking condition of the antitheft device of the present invention, the first rod member 3 can be extended for engaging opposed portions of a steering wheel with hooks 201, 30, as best shown in FIG. 8, without a key to lock the device. Furthermore, the second rod member 4 can also be extended into a dead corner between the front wind shield and a side window of the car for restricting the steering wheel from complete rotation.
When the locking member 70 of the locking means is oriented about 45 degrees to a bottom segment position where the flat top of the locking member 70 is located in a substantially horizontal position, the notched side of the locking member 70 is raised to lift the rod-like bearings 80, 81 by overcoming the biasing force of the springs 82, 83, as shown in FIG. 7, so as to withdraw the tenon members of the rod-like bearings 80, 81 from annular grooves into vertical passages 805, 815, thus permitting the rod members 3 and 4 to telescope in and out of the body member 2.
In order to prevent the rod members 3, 4 from being accidentally released from the tubes 20, 21 of the body member 2 during pulling of the rod members 3, 4 to extend same into a locking condition, the oval-shaped guide bodies 5, 6 secured to the inner ends of the rod members 3, 4 serve to prevent release of rod members 3, 4 from body member 2 thus avoiding the breaking of the front wind shield of the car and hitting of a passanger sitting nearby. As the diameters of the openings 200, 210 are smaller than the long diameters of the oval-shaped guide bodies 5, 6, the inner ends of the rod members 3, 4 carrying the guide bodies 5, 6 are always confined within their respective central passages in the tubes 20, 21 while permitting either of the rod members 3, 4 to be fully extended from body member 2.
Accordingly, the present invention provides an anti-theft device which is quick and simple to use. It will also be appreciated that the present invention, because of its configuration, presents a formidable obstacle to a potential thief. In this respect, a device according to the present invention provides no external pry points wherein a crow bar or screw driver can be inserted.
While the invention has been described with respect to the preferred embodiment thereof, it is obvious that various modifications can be made therein without departing from the spirit of the present invention which should be limited only by the scope of the claim.
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An antitheft device for attachment to a steering wheel of an automobile comprising an elongated body member having two parallel passageways extending along the longitudinal direction, a first hook secured to the body member for engagement with a portion of the steering wheel wherein the first hook engages the wheel from the inside thereof with the body member extending outward beyond the periphery of the steering wheel, a first elongated rod member adapted to move in telescopic fashion in one of the passageways of the body member, a second hook secured to the first hook for engaging the inside portion of the steering wheel diametrically opposed to the first hook, a second elongated rod member adapted to move in telescopic fashion in the other passageway and in a direction reverse to the first rod member, and the rod members may fully extend with respect to the body member to be locked at any of a plurality of selectable positions and prevented from being released from the body member.
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This application is a divisional of Ser. No. 08/051,736 filed Apr. 23, 1993
BACKGROUND OF THE INVENTION
The invention concerns a method for preheating melt-goods, i.e., materials to be molten, consisting of glass fragments and glass batching or such bulk goods, using a heating gas, wherein the melt-goods are vertically descending by gravity in a plurality of small columns and are preheated by heating-gas flowing in the opposite direction in the process of indirect heat-exchange, the temperature of the melt-goods columns increasing from the top toward the bottom whereas the temperature of the heating-gas flow gradually decreases from the bottom toward the top. The invention concerns also a plate heat-exchanger to carry out the method.
The German patent documents Nos. 32 17 414 C1 and 37 16 687 C1 disclose equipment, i.e., plate heat-exchangers, for carrying out the above stated method. Such known equipment operates in a problem-free manner as long as the bulk-goods to be preheated are dry, as in that case they will easily descend by gravity through the ducts of the equipment or plate heat-exchanger, without adhesion, caking or lastly clogging bridge-formation coming into being. This is also the case to some extent for broken glass when moist because enough hollows will form between the glass fragments to allow the steam generated during preheating to escape through the top of the equipment or plate heat-exchanger. If however the bulk or melt-goods to be preheated are moist glass fragments and moist or dry glass batching, and this shall be the rule, the above methods do fail. In such instances the dreaded adhesions and bridge-formations arise in the plate heat-exchanger and the downward flow of the goods to be preheated is interrupted, i.e., blocked. One of the reasons for such phenomena is steam produced from the basic moisture of the glass batching generated when heating this glass batching to above 100° C., i.e., when it is being preheated. Lastly the water of crystallization in the soda portion of the glass batching contributes to the generation of steam in the course of this preheating. Because evaporation only starts at a depth between about 1 and 2 m when preheating such bulk goods, then when charging broken glass and glass batching the steam no longer can escape upwardly from the charged material because latter acts like a stopper. As already mentioned, because of the steam condensing in the ducts of the plate heat-exchanger, bridges may be formed and hence blocking may arise. Known solutions to this problem are mechanically complex and expensive.
The German patent document No. 40 00 358 A1 discloses a method and a heat-exchanger for drying and pre-heating a melt-good consisting of glass fragments and glass batching, where one or only a few columns of the melt-good descending by gravity are transversely crossed by the heating gas: contrary to the initially cited method, this signifies direct contact with the heating gas. The steam so generated is evacuated laterally together with the flow of heating gas used for drying and preheating, without the steam condensing. However this method is not immediately applicable when a larger number of melt-good columns are involved which are hermetically sealed laterally and, because of gravity, migrate from top to the bottom and in the process are preheated by heating gas flowing in the opposite direction and (indirectly) by means of heat-exchange surfaces. An upper introduction means for the melt-good to be preheated is not heated and therefore is unutilized for drying, only enlarging the equipment height. However when the input material is moist, steam already may form in the transition zone between this introduction means and the preheating segment of this known equipment: it may condense and cause clogging.
SUMMARY OF THE INVENTION
The object of the invention is to ensure for a method of the initially cited kind that in the event of moist input, melt-goods, these can descend unhampered in small columns and shall not be blocked during such descent by bridges being formed, by agglomerations or the like.
The invention solves the above problem by a drying stage for moist melt-goods preceding the preheating operation, the moisture being evaporated in the drying stage within an intake zone of the melt-goods by means of a separate feed of hot heating gas to the already cooled flow of hot gas, and in that the melt-goods columns pass through cavities through which the steam escapes to the outside, as a result of which condensation is prevented and only dry melt-goods enter the preheating stage. By introducing a hot heating gas, preferably the exhaust gas from the glass-melting furnace, at about 600° C., into the melt-goods intake zone, the evaporation of the moisture entrained by such melt-goods, in particular of the glass batching, is already initiated at that stage and simultaneously the steam is exhausted from this region to the outside, whereby condensation is precluded. After the melt- or charge-goods have been dried in their intake zone they arrive in the dry, fluid or friable state at the preheating zone proper where they may descend by gravity in an unhampered manner and can be preheated in the process. The pre-drying stage offers the decisive significance of allowing the steam to flow outwardly through cavities located laterally off the melt-goods columns, but these cavities also may be formed within the melt-goods columns.
A plate heat-exchanger with a plurality of small vertical ducts open at the top and bottom and laterally spaced is used to carry out the above method, the ducts serving to transmit the melt-good by gravity, the cavities between the melt-goods receiving ducts serving to guide the hot gas, the exchanger further including a lower feed conduit and an upper exhaust conduit for the heating gas and evincing furthermore, when viewed from top toward the bottom, first a drying zone followed by the melt-goods preheating zone, the drying zone comprising means for introducing a hot heating gas into the heating-gas guide-cavities and also means with cavities to evacuate steam escaping from the melt-goods and mounted in the plate heat-exchanger transversely to the direction of displacement of the melt-goods and issuing at least by one end from the plate heat-exchanger.
Whereas the charged material forms so-to-speak stoppers in the narrow ducts for melt-goods transmission in the state of the art initially mentioned, whereby steam cannot escape through the top and hence its condensation is enhanced. In the invention, on the other hand, the steam is evacuated to the outside through cavities arranged transversely to the direction of motion of the melt-good. The hot heating gases fed to the drying zone are advantageously tapped from the main hot-gas feed line at the lower end of the plate heat-exchanger. The already cooled hot gases flowing through the plate heat-exchanger are mixed in the drying zone with the hot heating gas and thereby are raised to a temperature assuring evaporation of the moisture of the melt-goods in the drying zone.
In a further embodiment of the invention, the drying zone starts near the melt-goods receiving-end of the heat exchanger at a goods-depth of about 1-2 m. This depth is selected because the heating gases already have been cooled in this range and appropriately therefore water evaporation is initiated at this level by introducing suitably hot exhaust gases.
In yet a further embodiment of the invention, the means supplying hot heating gases and the means evacuating steam from the drying zone are mounted each directly next to the other in the vertical direction. The vertical size of the drying zone can be matched then to the particular requirements.
In still a further embodiment of the invention, the means evacuating steam from the drying zone appropriately comprise channel-shaped bodies open at their underside or perforated or slotted at the underside which issue at least by one end from the plate heat-exchanger.
The channel-shaped bodies for evacuating the steam from the drying zone can be arrayed in one or more vertical and mutually spaced planes.
Where the plate heat-exchanger consists of heat-exchanging units designed to be crossed horizontally by the heating gas and wherein the heating-gas guide-cavities of vertically adjacent heat-exchanger units are connected by externally mounted heating-gas bypass ducts, another embodiment of the invention provides that each hot heating-gas feed conduit issues into the upper part of the uppermost bypass duct or into the upper part of a few of the upper bypass ducts, and the channel-shaped bodies shall be advantageously integrated into their own intermediate units mounted between every two heat-exchanger units. The invention then is also advantageously applicable to a plate heat-exchanger consisting of superposed heat-exchanger units, the steam evacuation being carried out through channel-shaped bodies in the intermediate units. The lengths and widths of these intermediate units correspond to those of the heat-exchanger units but preferably shall be less. The hot heating gases mix with the already cooled heating gases in the bypass ducts and the mixture then is raised to a temperature assuring moisture evaporation in the drying zone.
Appropriately the steam-evacuating channel-shaped bodies are so integrated into their unit as to be always mounted between two evacuation cavities for the heating gas of vertically adjacent heat-exchanger units. Because of this design, the steam evacuation from the drying zone is carried out without thereby hampering the downward flow of the melt or bulk goods in the vertical ducts.
In still another embodiment mode of the invention, the steam-evacuating channel-shaped bodies consist of reversely mounted U-channels, V-bars, H-bars or shapes with similar cross-sections.
Appropriately the cross-sectional width of the H-bars essentially corresponds to that of the heating-gas evacuation-cavities which are vertically flush with the upper edges of the H-bars.
The descent of the melt or bulk goods in the plate heat-exchanger is further facilitated by integrating in a prone manner angle irons or shapes with a cross-section similar to the H-bars at vertical spacings from the H-bars and parallel to them, being flush with the H-bars, the legs or feet of such shapes forming guides for the melt-good flowing through the intermediate unit.
The invention is elucidated below in relation to the drawings of an illustrative embodiment.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sideview of a plate heat-exchanger with a drying zone and a subsequent preheating zone for the melt-goods, the flow of the heating gas through the heat exchanger being denoted by the solid arrows and dot-dashed arrows indicating the steam exhaust from the heat exchanger;
FIG. 2 is a sideview of the upper part of the heat exchanger of FIG. 1, showing of its drying zone and an upper segment of the adjoining preheating zone; and
FIG. 3 is a front view of the part shown in FIG. 2 in the direction of the arrow A without the bypass ducts, in partly cutaway form, to elucidate the steam evacuation by means of the H-bars.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The plate heat-exchanger 10 preheats a melt-good consisting of broken glass and glass batching before being introduced into a melting tub. The melt-good is preheated in the plate heat-exchanger 10 to several hundred °C. (depending on dwell time and quantity and temperature of the available heating gas); the heating gas preferably shall be the flue gas from the glass melting equipment.
The plate heat-exchanger 10 is modularly composed of heat-exchanger units 11. Illustratively in FIG. 1, nine vertically superposed heat-exchanger units 11 constitute the plate heat-exchanger 10. In this embodiment, intermediate units 12 are mounted between the three upper last heat-exchanger units 11: their function is discussed further below. The heat-exchanger units 11 are substantially identical, however the upper three illustratively are less in height. Again they are mutually connected in a substantially identical manner. An input or receiving shaft 13 for the melt-good to be preheated is affixed to the uppermost heat-exchanger unit 11. The preheated melt-good that has passed through the plate heat-exchanger 10 leaves the lowermost heat-exchanger unit 11 at its open underside through several funnel-shaped shafts 14 and drops onto chute-shaped vibration-conveyors 15 (FIGS. 2 and 3) which directly move the preheated melt-good to a melting tub (not shown) of the glass melting equipment.
Presently one of the heat-exchanger units 11--which are all alike--shall be discussed more comprehensively. The unit comprises an upper and lower frame-like affixing flange 16 which is affixed in vertically flush manner to a support frame 19 consisting of vertical and horizontal shapes 17 and 18. The support frame 19 bears many equidistant hollow heating plates 20 of which the mutual spacing is determined by spacers 21. The hollow heating plates 20 stand on edge and are open on both sides (left and right in FIG. 2), whereas they are sealed by strips 22 at the top and bottom. The spaces or ducts 23 between the heating plates 20 are open at the top and bottom whereas they are sealed laterally. The spaces or ducts 23 of all heat-exchanger units 11 of the plate heat-exchanger 10 are mutually flush vertically and their function is to pass the melt-goods to be preheated, which consist of glass fragments and glass batching. The melt-good to be preheated therefore descends in the form of a plurality of comparatively narrow columns through the plate heat-exchanger 10, the columns also passing through the intermediate units 12.
The melt-good to be preheated is uniformly introduced by an omitted conveyor means into the ducts 23 between the heating plates 20, as a result of which it may slide down within these ducts on account of gravity. When the plate heat-exchanger 10 is started, the vibration conveyors 15 are at rest, and therefore the melt-good can build up gradually in the ducts 23 as filling proceeds. As soon as the ducts 23 are entirely filled with the melt-good, the plate heat-exchanger 10 is started to preheat the melt-good, the operation being carried out "in-line".
The nine heat-exchanger units 11 of the plate heat-exchanger 10 of FIG. 1 are held vertically flush at their flanges 16 and connected by means of omitted screws. The hollow heating plates 20, as already mentioned, are sealed at the top and bottom and open only on the side. As shown by FIG. 1, a feed conduit 24 for the heating gas is flanged onto the lowermost heat-exchange unit 11. The left sides of the outwardly open hollow heating plates 20 of the two lowermost heat-exchanger units 11 shown in FIG. 1 are connected to each other by a flange-affixed bypass duct 25 for the heating gas. In similar manner a further bypass duct 25 for the heating gas connects the open right sides of the hollow heating plates 20 of the second and third heat-exchanger units 11 as seen from below in FIG. 1. The left open sides of the heating plates 20 of the third and fourth heat-exchanger units 11 seen from below are similarly connected by a further heating-gas bypass-duct 25. In this manner the left and right sides of the hollow heating plates 20 of vertically adjoining heat-exchanger units 11 are alternatingly connected to one another by bypass ducts 25, an exhaust conduit 26 for the heating gas being flange-affixed to the left open side of the hollow heating plates 20 of the uppermost heat-exchanger unit 11. In this manner the heating gas flows horizontally through the heat-exchanger units 11 in alternating directions, as a result of which a meandering heating-gas flow through the plate heat-exchanger 10 is obtained as indicated by the arrows of FIG. 1.
When the plate heat-exchanger 10 is run to preheat the melt-good, heating or flue gas at a temperature between 400° and 700° C. is fed through the feed conduit 24 into the cavities 20a of the heating plates 20 into the heat-exchanger units 11. The heating gas flows upward in meandering manner through the individual heat-exchanger units 11 and leaves the plate heat-exchanger 10 through the exhaust conduit 26, the heating gas gradually cooling on its way from the bottom to the top. As a rule the input material is a moist melt-good, which would tend to form bridges in the ducts 23 during preheating and hence would block the vertical flow of the good: the invention therefore proposes to place a drying zone for the moist melt-good ahead of the preheating zone (FIG. 1). The humidity in the melt-good is evaporated in this drying zone by means of a separate feed of hot heating gas to the already cooled flows of heating gas. At the same time the melt-good passes through cavities in this drying zone, the steam thereby being allowed to escape to the outside to prevent its condensation. Accordingly only dry melt-good which is fluid or friable in problem-free manner arrives at the preheating zone and it easily passes through the relatively narrow ducts 23. A so-called bypass duct 27 leads upward from the heating-gas feed conduit 24 to form the drying zone in the upper, i.e., input region of the plate heat-exchanger 10 and branches into two feed conduits 28 of relatively lesser inside diameters. One of the feed conduits 28 issues into the upper part of the right, uppermost bypass duct 25 of FIG. 1 and the other feed conduit 28 issues into the upper part of the left uppermost bypass duct 25 of FIG. 1. The hot heating-gas partial flows entering the cited bypass ducts 25 mix therein with the already comparatively much cooled main flow of heating gas which they heat to so high a temperature that when this mixture of heating gases passes through the cavities 20a in the heating plates 20 of illustratively the three upper heat-exchanger units 11 (of comparatively low heights) the moisture entrained by the melt-good shall evaporate. To the extent the steam is present in the ducts 23 of the uppermost heat-exchanger unit 11, it can escape upward and to the outside. The steam generated in the ducts 23 of the adjoining lower heat-exchanger units 11 can enter the cavities of the intermediate units 12. The steam is evacuated from these intermediate units 12 and accordingly it cannot condense and the melt-good, as already mentioned above, arrives at the preheating zone in a problem-free, fluid state.
Channel-shaped bodies, for instance in the form of H-bars 29, are integrated into each intermediate unit 12 to evacuate the steam. In the illustrative embodiment mode, the H-bars 29 are supported by square pipes 30 and 31 affixed to the end walls 32 of the intermediate units 12. The pipes 31 are open to the outside, but the pipes 30 are closed.
FIG. 3 shows that the H-bars 29 each are mounted in a plane between two hollow heating plates 20 of vertically adjacent heat-exchanger units 11. The cross-sectional width of the H-bars 29 corresponds to that of the heating plates 20 and thereby substantially to the width of the hot heating-gas guidance-cavities 20a in the heating plates 20. The arrangement furthermore is such that the H-bars 29 adjoin by the upper edges of their legs 33 the closed underside of the heating plates 20. Furthermore, in this embodiment, for instance angle irons 34 are mounted prone in the intermediate units 12 while being vertically spaced from but parallel to the H-bars 29. These angle irons 34 are affixed by their ends to the end walls 32 of the intermediate units 12. The angle irons 34 are vertically flush on the heating plates 20 of the particular next lower heat-exchanger unit 11. The two legs of each angle iron 34 form guides for the melt-good passing through the intermediate units 12 which they guide into the ducts 23 of the next lower heat-exchanger unit 11.
In the illustrative embodiment mode, the drying zone begins at a depth of approximately 1-2 m. Depending on circumstance, and in deviation from the embodiment mode, more than three intermediate units 12 may be provided to evacuate the steam. Again, a single intermediate unit 12 also may suffice. In lieu of the H-bars 29, other channel-shaped bodies of which the underside is open, perforated or slotted, may be used for steam evacuation. When the ducts 23 for melt-good transmission in the heat-exchanger units 11 are sufficiently wide, the steam-evacuating channel-shaped bodies also may be integrated in such manner in these ducts that they will be bypassed by the descending melt-good.
When being evacuated to the outside, the steam may be fed through pipe segments 31 into collecting conduits 35 which may issue into the exhaust conduit 26 for the cooled heating or flue gas. This feature offers the advantage that only one conduit is needed to evacuate the cooled heating or flue gas and the steam.
As an illustrative embodiment, a plate heat-exchanger 10 was selected that is constituted of individual heat-exchanger units 11 in the so-called modular way. However the invention also applies to a plate heat-exchanger which is a single unit onto which are mounted the means supplying the hot heating gas and evacuating steam. In that case the latter two means will then form the drying zone which is followed in the downward direction by the preheating zone consisting of a single unit.
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As a rule a melt-good consisting of glass fragments and glass batching will be moist and tend to agglomerate and bridge-form when being preheated in a plate heat-exchanger 10 whereby the travel of the melt-good through the plate heat-exchanger 10 may be blocked. To remedy these drawbacks, the preheating stage is preceded by a drying stage of the moist melt-good. For that purpose, in the intake zone of the melt-good, the moisture of the melt-good is evaporated by means of a separate feed of hot heating gas into the already cooled flows of heating gas. At the same time the heated melt-good is made to pass through cavities 12 through which the steam may escape to the outside. Thereby condensation shall be precluded and only fluid or friable melt-good arrives at the preheating stage.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of, and incorporates herein by reference in its entirety, the following U.S. Provisional Application: U.S. Provisional Application No. 60/969,267, filed Aug. 31, 2007.
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates to stabilized lithium metal powder (“SLMP”) having improved air and solvent stability and having a longer storage life. Such improved SLMP can be used in a wide variety of applications including organo-metal and polymer synthesis, primary lithium batteries, rechargeable lithium batteries, and rechargeable lithium ion batteries.
[0003] Lithium and lithium-ion secondary or rechargeable batteries have recently found use in certain applications such as in cellular phones, cameorders, and laptop computers, and even more recently, in larger power applications such as in electric vehicles and hybrid electric vehicles. It is preferred in these applications that the secondary batteries have the highest specific capacity possible but still provide safe operating conditions and good cycleability so that the high specific capacity is maintained in subsequent recharging and discharging cycles.
[0004] Although there are various constructions for secondary batteries, each construction includes a positive electrode (or cathode), a negative electrode (or anode), a separator that separates the cathode and anode, and an electrolyte in electrochemical communication with the cathode and anode. For secondary lithium batteries, lithium ions are transferred from the anode to the cathode through the electrolyte when the secondary battery is being discharged, i.e., used for its specific application. During this process, electrons are collected from the anode and pass to the cathode through an external circuit. When the secondary battery is being charged or recharged, the lithium ions are transferred from the cathode to the anode through the electrolyte.
[0005] Historically, secondary lithium batteries were produced using non-lithiated compounds having high specific capacities such as TiS 2 , MoS 2 , MnO 2 and V 2 O 5 , as the cathode active materials. These cathode active materials were often coupled with a lithium metal anode. When the secondary battery was discharged, lithium ions were transferred from the lithium metal anode to the cathode through the electrolyte. Unfortunately, upon cycling, the lithium metal developed dendrites that ultimately caused unsafe conditions in the battery. As a result, the production of these types of secondary batteries was stopped in the early 1990's in favor of lithium-ion batteries.
[0006] Lithium-ion batteries typically use lithium metal oxides such as LiCoO 2 and LiNiO 2 as cathode active materials coupled with a carbon-based anode. In these batteries, the lithium dendrite formation on the anode is avoided thereby making the battery safer. However, the lithium, the amount of which determines the battery capacity, is totally supplied from the cathode. This limits the choice of cathode active materials because the active materials must contain removable lithium. Furthermore, the delithiated products corresponding to LiCoO 2 and LiNiO 2 that are formed during charging (e.g. Li x CoO 2 and Li x NiO 2 where 0.4<x<1.0) and overcharging (i.e. Li x CoO 2 and Li x NiO 2 where x<0.4) are not stable. In particular, these delithiated products tend to react with the electrolyte and generate heat, which raises safety concerns.
[0007] Another option is lithium metal. Lithium metal, particularly lithium metal powder; however, because of its high surface area, can be a deterrent for its use in a variety of applications because of its pyrophoric nature. It is known to stabilize lithium metal powder by passivating the metal powder surface with CO 2 such as described in U.S. Pat. Nos. 5,567,474, 5,776,369, and 5,976,403, the disclosures of which are incorporated herein in their entireties by reference. The CO 2 -passivated lithium metal powder, however, can be used only in air with low moisture levels for a limited period of time before the lithium metal content decays because of the reaction of the lithium metal and air.
[0008] Thus there remains a need for stabilized lithium metal powder that has improved stability and storage life.
SUMMARY OF THE INVENTION
[0009] The present invention provides a lithium metal powder protected by a substantially continuous layer of a polymer. Such a substantially continuous polymer layer provides improved protection such as compared to typical CO 2 -passivation. The resulting lithium metal powder has improved air and solvent stability and improved storage life. Furthermore, the polymer-protected lithium metal powder exhibits significantly better stability in N-methyl-2-pyrrolidone (NMP), which is commonly used as a slurry solvent in the electrode fabrication process, and reacts with unprotected lithium.
[0010] Objects and advantages of the present invention will become more apparent by describing various embodiments of the present invention with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an ARSST stability test of CO 2 -coated SLMP (comparative example 2) with NMP as received (<100 ppm moisture) and 0.6% water doped NMP.
[0012] FIG. 2 is an ARSST stability test of PEO-coated SLMP (example 2) with 0.6% water doped NMP.
[0013] FIG. 3 is an ARSST stability test of EVA-coated SLMP with 0.6% water doped NMP, example 10.
[0014] FIG. 4 is an ARSST stability test of SBR-coated SLMP with 0.6% water doped NMP, example 7.
[0015] FIG. 5 is an ARSST stability test of BYK P 104-coated (low molecular weight polycarboxylic acid polymer) SLMP with 0.6% water doped NMP, example 3.
[0016] FIG. 6 demonstrates the effect of a polymer-coated lithium on the electrochemical performance
[0017] FIG. 7 is an ARSST stability test of CO 2 -coated SLMP and Example 11.
[0018] FIGS. 8A , 8 B, and 8 C are SEM images for samples prepared using different process parameters.
[0019] FIG. 9A is a comparison of metallic lithium concentration in anhydrous NMP as a function of time.
[0020] FIG. 9B is a comparison of metallic lithium concentration in 0.6% water doped NMP as a function of time.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In the drawings and the following detailed description, various embodiments are described in detail to enable practice of the invention. Although the invention is described with reference to these specific embodiments, it will be understood that the invention is not limited to these embodiments. But to the contrary, the invention includes numerous alternatives, modifications and equivalents as will become apparent from consideration of the following detailed description and accompanying drawing.
[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms “a”, “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Furthermore, the term “about,” as used herein when referring to a measurable value such as an amount of a compound or agent of this invention, dose, time, temperature, and the like, is meant to encompass variations of 20%, 10%, 5%, 1%, 0.5%, or even 0.1% of the specified amount.
[0023] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinarv skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0024] All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. However, the citation of a reference herein should not be construed as an acknowledgement that such reference is prior art to the present invention described herein.
[0025] In accordance with the present invention, lithium dispersions are prepared by heating the lithium metal powder in a hydrocarbon oil to a temperature above its melting point, subjecting to conditions sufficient to disperse the molten lithium, agitating or stirring vigorously, and contacting the lithium metal powder with a polymer at a temperature that is between this temperature and at or above the melting point of the lithium to provide a substantially continuous layer of the polymer. The substantially continuous layer of polymer has a thickness of 25 to 200 nm, and often has a thickness of 80 to 120 nm. Other alkali metals such as sodium and potassium can be coated according to the present invention.
[0026] Suitable polymers can be polymers that are water resistant and that are lithium-ion conducting or non-lithium ion conducting, for example if they are soluble in the common electrolyte solvents. The polymers may be reactive with lithium or non-reactive with lithium. The following are merely examples of the polymer compounds and include: polyurethanes, polytetrafluoroethylene, polyvinyl fluoride, polyvinyl chloride, polystyrenes, polyethylenes, polypropylene, polyformaldehyde (Delrin), styrene-butadiene-styrene block polymers, ethylene vinyl acetate, ethylene acrylic acid copolymers, polyethylene oxide, polyimides, polythiophenes, poly(para-phenylene), polyanilines, poly(p-phenylenevinylene), silica titania copolymers, unsaturated polycarboxylic acid polymer and polysiloxane copolymers, etc.
[0027] The polymer can be introduced to contact the lithium droplets during the dispersion, or at a lower temperature after the lithium dispersion has cooled. It is understood that combinations of different types of polymers with different chemical compositions, molecular weights, melting points and hardness could be used to achieve specific coating characteristics for particular applications. For example, degree of stickiness could be controlled to allow introduction of the SLMP using “transfer release paper” concept, where certain degree of stickiness is required. It is also understood that the monomers could be used to create an in-situ polymer coating on the surface of the lithium particles.
[0028] Furthermore, it is beneficial to combine polymer or polymer mixtures with some inorganic coating, for example, Li 2 CO 3 , LiF, Li 3 PO 4 , SiO 2 , Li 4 SiO 4 , LiAlO 2 , Li 2 TiO 3 , LiNbO 3 , Al 2 O 3 , SiO 2 , SnO 2 , ZrO 2 , and the like, to improve both air stability and polar solvent stability that would allow both safer handling and possibility of using commonly used polar solvents that dissolve commonly used polymer binders. It is recognized that most polymers are soluble in non-polar solvents at elevated temperatures and solubility at room temperature could be significant (see, Table 2) and washing solvents used to remove oil from the particles should be selected appropriately. Sometimes, dry non-stabilized or stabilized powders could be transferred into non-polar solvents that are compatible with lithium and polymer coatings could be deposited using for example, rotovap techniques, thus avoiding solubility issue.
[0029] Suitable polymers described above, could produce two types of coatings on lithium particles: first type representing physical or adhesive type and second, representing chemically bonded coatings where polymers with functional groups, are used. For example, polyethylene (PE), polypropylene (PP), and polystyrene (PS) contain carbon-hydrogen groups that do not react with Li. This type of polymer is valuable as a coating reagent for lithium particles in that the physical Van der Waals interaction allows carbon-hydrogen molecules to adhere onto the surface of lithium particles. On the other hand, polymers such as, for example, poly(acrylic acid) and ethylene vinyl acetate do react with lithium since they contain the acid functional groups, thus forming a chemically bonded coating.
[0030] By altering the processes and process parameters and the order of the reagents addition in polymer-coated lithium particles can result with distinct surface properties. Different process parameters can result in samples with different surface properties (see, FIG. 7 ). Polymers or polymer mixtures could be introduced above the melting point of lithium before or after other dispersants (e.g., wax) and coating reagents additions to enhance the chemical bonding and uniformity of protecting layer by changing the reaction interfaces. The cooling profile, the temperature at which the polymer is introduced during the dispersion process could be used to control degree of crystallinity and obtain samples with pre-determined degree of stickiness.
[0031] The following examples are merely illustrative of the invention, and are not limiting thereon.
EXAMPLES
Comparative Example 1
[0032] Battery grade lithium metal (405 g) was cut into 2×2 inch pieces and charged under constant flow of dry argon at room temperature to a 3 liter stainless steel flask reactor with a 4″ top fitted with a stirring shaft connected to a fixed high speed stirrer motor. The reactor was equipped with top and bottom heating mantles. The reactor was then assembled and 1041.4 g of Penetek oil (Penreco, Division of the Penzoil Products Company) was added. The reactor was then heated to about 200° C. and gentle stirring was maintained in the range of 250 rpm to 800 rpm to ensure all metal was molten, argon flow was maintained throughout the heating step. Then the mixture was stirred at high speed (up to 10,000 rpm) for 2 minutes. Oleic acid, 8.1 g was charged into the reactor and high speed stirring continued for another 3 minutes followed by the 5.1 g CO 2 addition. Then the high speed stirring was stopped, heating mantles removed and dispersion was allowed to cool to about 50° C. and transferred to the storage bottles. Further, lithium dispersion was filtered and washed three times with hexane and once with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium while under argon flow. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to a tightly capped storage bottles.
Comparative Example 2
[0033] Penetel™ mineral oil (4449 g) and 1724 g of battery grade lithium metal were added to a 15 liter jacketed dispersion reactor under an argon atmosphere at room temperature. The reactor was then heated from room temperature to 200° C. by pumping hot heat transfer fluid through the jacket. During heating the dispersion agitator was kept at low speed to facilitate heat transfer. Once the temperature inside the reactor reached 200° C., the dispersion agitator speed was increased to 5000 rpm. After 3.5 minutes of high speed stirring, 36 g of oleic acid was charged into the reactor and high speed stirring continued for another 4.5 minutes followed by addition of 22 g of CO2 gas. After an additional 4 minutes of high speed stirring, the high speed agitator was turned off and the reactor contents were brought down to room temperature. During the cooling process, the dispersion was kept in suspension using low speed agitation. Lithium dispersion was transferred under argon pressure to a batch filter and the mineral oil was allowed to drain out. The dispersion in the filter was washed four times with hexane; then dry argon was blown through the filter to remove any remaining volatile organics. The dry stabilized polymer coated lithium dispersion was removed from the filter as a final product.
Example 1
[0034] A lithium dispersion (47.30 g) passivated with CO 2 gas in oil (27.5%) containing 13.01 g of lithium with a medium particle size of 45 micron was charged into 120 ml hastelloy can equipped with a 1″ Teflon coated stir bar. 1.3 g of PEO (Polyox WSRN80) dry powder was also added to the can. The solution was heated from ambient to 75° C. at a rate of 5° C./min and held for 10 minutes. The sample was further heated from 75° C. to 175° C. at 5° C./min and held for one hour. This mixture was continuously stirred at 200 rpm during the heating phase. Sample was allowed to cool to room temperature and transferred to the storage bottle. Further, lithium dispersion was filtered and washed three times with hexane in an enclosed, sintered glass filter funnel and twice with n-pentane to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 2
[0035] A lithium dispersion (45.00 g) passivated with CO 2 gas in oil (27.5.%) containing 12.37 g of lithium with a medium particle size of 45 micron was charged into 120 ml hastelloy can equipped with a 1″ Teflon coated stir bar. 1.2 g of PEO (Polyox WSRN80) dry powder was also added to the can. The solution was heated from ambient to 75° C. at a rate of 5° C./min and held for 10 minutes. The sample was further heated from 75° C. to 175° C. at 5° C./min and held for one hour. Finally the sample was heated from 175° C. to 200° C. at 20° C./min. This mixture was continuously stirred at 200 rpm during the heating phase. Sample was allowed to cool to room temperature and transferred to a storage bottle. Further, lithium dispersion was filtered and washed three times with hexane and twice with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 3
[0036] A lithium dispersion (44.00 g) passivated with CO 2 gas in oil (27.5%) containing 12.10 g of lithium with a medium particle size of 45 micron was charged into 120 ml hastelloy can equipped with a 1″ Teflon coated stir bar. The solution was heated to 75° C. and 1.2 ml of BYK-P 104 S (BYK Chemie) was added to the lithium dispersion. This mixture was continuously stirred at 200 rpm for one hour. Sample was allowed to cool to room temperature and transferred to a storage bottle. Further, lithium dispersion was filtered and washed three times with hexane and twice with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 4
[0037] A stabilized lithium dispersion (54.99 g) in oil (11.275%) containing 6.20 g of lithium with a medium particle size of 58 micron was charged into 120 ml hastelloy can equipped with a 1″ Teflon coated stir bar. At ambient temperature 0.62 g of SBR in a form of 10% solution in p-xylene (Aldrich) was added to the lithium dispersion. This mixture was continuously stirred at 200 rpm for 19 hours. Sample was transferred to a storage bottle. Further, lithium dispersion was filtered and washed three times with hexane and twice with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 5
[0038] A stabilized lithium dispersion (54.68 g) in oil (11.275%) containing 6.17 g of lithium with a medium particle size of 58 micron was charged into 120 ml hastelloy can equipped with a 1″ Teflon coated stir bar. At ambient temperature 0.62 g of EVA (Aldrich) in a form of 5% solution in p-xylene (Aldrich) pre-dissolved was added to the lithium dispersion. This mixture was continuously stirred at 200 rpm for 2.5 hours. Sample was transferred to a storage bottle. Further, lithium dispersion was filtered and washed three times with hexane and twice with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 6
[0039] A stabilized lithium dispersion (54.00 g) in oil (11.275%) containing 6.09 g of lithium with a medium particle size of 58 micron was charged into 120 ml hastelloy can equipped with a 1″ Teflon coated stir bar. At ambient temperature 0.5 ml of butadiene (Aldrich) and 0.5 ml of styrene (Aldrich) were added to the lithium dispersion. This mixture was continuously stirred at 200 rpm for 1 hour. Sample was transferred to a storage bottle. Further, lithium dispersion was filtered and washed three times with hexane and twice with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 7
[0040] 10.0 g of SLMP (stabilized lithium metal powder) was weighed into a 1 liter round bottom flask. 32.1 g of p-xylene (Aldrich) and 0.28 g SBR in a form of 10% solution in p-xylene (Aldrich) pre-dissolved were added to the flask. The flask containing the mixture was attached to a rotavap vacuum extractor and heated with rotation to 70° C.. After holding the temperature at 70° C. for 15 minutes vacuum was applied to strip the solvent. The sample was then transferred to a storage bottle.
Example 8
[0041] 4.0 g of non-stabilized lithium powder with a medium particle size of 58 micron and 36 g p-xylene (Aldrich) were charged into 120 ml hastelloy can equipped with a 1″ Teflon coated stir bar. This mixture was heated to 40° C. while mixing at 200 rpm. At 40° C., 0.40 g of EVA in a form of 10% solution in p-xylene (Aldrich) pre-dissolved was added to the lithium, p-xylene mixture. This mixture was continuously stirred at 200 rpm for 20 hours. Sample was transferred to a 200 ml round bottom flask. Further, the p-xylene was evaporated away by passing dry argon over the sample. The resulting free-flowing powder was transferred to a tightly capped storage bottle.
Example 9
[0042] A stabilized lithium dispersion (2149.8 g) in oil (11.0%) containing 236.5 g of lithium with a medium particle size of 58 micron was charged into 3 liter round bottom flask equipped with a propeller type variable speed mixer. At ambient temperature 23.8 g EVA (Aldrich) in a form of 10% solution in p-xylene (Aldrich) was added to the lithium dispersion. This mixture was continuously stirred at 500 rpm for 4 hours. Sample was transferred to a storage bottle. Further, lithium dispersion was filtered and washed three times with hexane and twice with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 10
[0043] A stabilized lithium dispersion (1127.0 g) in oil (11.2%) containing 126.6 g of lithium with a medium particle size of 63 micron was charged into 5 liter round bottom flask equipped with a propeller type variable speed mixer. The temperature was raised to 41.3° C. and 12.5 g EVA (Aldrich) in a form of 5% solution in p-xylene (Aldrich) was added to the lithium dispersion. This mixture was continuously stirred at 500 rpm for about 6 hours at 40° C. and then for another ˜18 hours at the ambient temperature. Sample was transferred to a storage bottle. Further, lithium dispersion was filtered and washed three times with hexane and twice with n-pentane in an enclosed, sintered glass filter funnel to remove the hydrocarbon oil medium. The funnel was heated with a heat gun to remove traces of the solvents and the resulting free-flowing powder was transferred to tightly capped storage bottles.
Example 11
[0044] Penetek™ mineral oil 15390 g of and 4415 g of battery grade lithium metal were added to a 57 liter jacketed dispersion reactor under an argon atmosphere at room temperature. The reactor was then heated from room temperature to 190° C. by pumping hot heat transfer fluid through the jacket. During heating the dispersion agitator was kept at low speed to facilitate heat transfer to the reactor contents. Once the temperature inside the reactor reached 190° C., the dispersion agitator speed was increased to 4800 rpm. After three minutes of high speed stirring, 90 g of oleic acid was charged into the reactor and high speed stirring continued for another four minutes followed by addition of 56 grams of CO 2 gas. After an additional six minutes of high speed stirring, 154 g of polyethylene oxide (PEO) granules were added to the reactor and high speed stirring continued for three more minutes. Then the high speed agitator was turned off and the reactor contents were brought down to room temperature. During the cooling process, the dispersion was kept in suspension using low speed agitation. The lithium dispersion was transferred under argon pressure to a batch filter and the mineral oil was allowed to drain out under argon pressure. The dispersion was washed four times with hexane; then dry argon was blown through the filter to remove any remaining volatile organics. The dry stabilized polymer coated lithium dispersion was removed from the filter as a final product.
[0045] FIGS. 1-5 and 7 below demonstrate stability of the polymer-coated samples in NMP, which is widely used as a solvent in the electrode fabrication process in the rechargeable lithium-ion battery industry. The following procedure is used to conduct this test: SLMP and solvent are loaded into the test cell under Argon, then the test cell is brought up to 25° C. and isothermal hold continues for 72 hours, then the temperature is ramped up to 55° C. and isothermal hold continues for 48 hours; the mixture is continuously stirred. The metallic lithium content of samples is measured upon completion of the test: the higher the content the better protecting properties of the coating are. As could be seen in Table 1 below, the lithium concentration is 17.3% and higher for the samples in the presented examples. No adverse effects on electrochemical properties of polymer additive to graphite electrode were observed. (See FIG. 6 .) FIGS. 8A , 8 B, and 8 C show the different surface properties of Examples 5, 8, and 9 due to process parameter changes. A separate test was conducted to determine lithium content as a function of time with water doped NMP and significant improvement was observed. (See, FIGS. 9A and 9B .)
[0000]
TABLE 1
Examples of the residual metallic lithium concentration measured
using standard ARSST test with the 0.6% water doped NMP
Coating
Residual metallic
agent
Example
Lithium concentration
EVA
Example 10 (785-106)
24.3%
SBR
Example 7 (767-200)
17.3%
PEO
Example 1
38.2%
(PEOR043007)
PEO
Example 2
30.9%
(PEOR050807)
[0000]
TABLE 2
Examples of polymer's solubility in selected solvents
LuWax A
SBR
EVA
PEO
Hexane
0.46%
3.92%
1.21%
0.03%
Pentane
0.48%
4.1%
0.46%
0.03%
Xylene
0.81%
>10%
>10%
>10%
[0046] Having thus described certain embodiments of the present invention, it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope thereof as hereinafter claimed. The following claims are provided to ensure that the present application meets all statutory requirements as a priority application in all jurisdictions and shall not be construed as setting forth the full scope of the present invention.
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The present invention provides a lithium metal powder protected by a substantially continuous layer of a polymer. Such a substantially continuous polymer layer provides improved protection such as compared to typical CO 2 -passivation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention deals with the field of parachutes and other aerial descent control mechanisms and, in particular, in regard to designs for the purpose of more rapidly and in a more controlled manner achieving inflation of the canopy of such parachutes. The use of pocket bands positioned attached adjacent at least some of the radial lines between adjacent gores of the canopy have been utilized heretofore. The present invention provides a unique configuration for such pocket bands which orients them angularly with respect to the radial lines and with respect to the movement of air which causes inflation of the canopy in order to enhance lateral movement of the lowermost edge of the canopy to a more rapidly and in a more controlled manner inflate the parachute. This improved configuration for the pocket bands allows more efficient and reliable canopy inflation than with pocket bands utilized heretofore.
2. Description of the Prior Art
Various devices have been designed for the purposes of enhancing initial inflation of a parachute including pocket bands and other devices such as shown in U.S. Pat. No. 1,509,410 patented Sep. 23, 1924 to J. W. Ruff on a “Self-Opening Parachute”; and U.S. Pat. No. 1,877,227 patented Sep. 13, 1932 to W. L. Cunningham on an “Air-Vent Parachute”; and U.S. Pat. No. 1,951,864 patented Mar. 20, 1934 to L. L. Driggs, Jr. and assigned to International Flare-Signal Company on a “Parachute”; and U.S. Pat. No. 2,404,672 patented Jul. 23, 1946 to C. A. Volf on a “Vented Parachute”; and U.S. Pat. No. 2,505,954 patented May 2, 1950 to L. P. Frieder et al and assigned to Reconstruction Finance Corporation on a “Pilot Parachute”; and U.S. Pat. No. 2,511,263 patented Jun. 13, 1950 to E. F. Hiscock on a “Parachute Construction”; and U.S. Pat. No. 2,525,798 patented Oct. 17, 1950 to M. Hattan on a “Shockless Parachute”; and U.S. Pat. No. 2,974,913 patented Mar. 14, 1961 to A. J. Steinthal and assigned to M. Steinthal & Co., Inc. on a “Pilot Chute With Auxiliary Deployment Canopy”; and U.S. Pat. No. 3,013,753 patented Dec. 19, 1961 to C. W. Hughes et al and assigned to Capital Parachuting Enterprises on a “Steerable Parachute”; and U.S. Pat. No. 3,055,621 patented Sep. 25, 1962 to J. Martin on a “Parachute Apparatus”; and U.S. Pat. No. 3,099,426 patented Jul. 30, 1963 to P. M. Lemoigne on a “Parachute”; and U.S. Pat. No. 3,195,842 patented Jul. 20, 1965 to K. R. A. Wilson and assigned to Irving Air Chute Company, Inc. on a “Parachute”; and U.S. Pat. No. 3,393,885 patented Jul. 23, 1968 to O. W. Neumark on “Parachutes”; and U.S. Pat. No. 3,434,681 patented Mar. 25, 1969 to V. G. Bockelmann and assigned to the United States of America as represented by the Secretary of the Navy on a “Parachute Canopy Deflation Apparatus”; and U.S. Pat. No. 3,452,951 patented Jul. 1, 1969 to K. R. A. Wilson and assigned to Irvin Industries, Inc. on a “High Drag Efficiency Parachute Canopy”; and U.S. Pat. No. 3,525,491 patented Aug. 25, 1970 to D. T. Barish and assigned to Barish Associates, Inc. on a “Parachute”; and U.S. Pat. No. 3,703,268 patented Nov. 21, 1972 to M. Pravaz and assigned to Etudes et Fabrications Aeronautiques on a “Parachute Container And The Application Of The Container To A Parachute”; and U.S. Pat. No. 4,487,384 patented Dec. 11, 1984 to H. V. G. Astrand and assigned to Irvin Fallskarms AB on a “Parachute Canopy”; and U.S. Pat. No. 4,607,813 patented Aug. 26, 1986 to W. W. Jeswine and assigned to William W. Jeswine on a “Parachute Assembly”; and U.S. Pat. No. 4,813,636 patented Mar. 21, 1989 to M. J. Lindgren and assigned to Lockheed Missiles & Space Company, Inc. on an “Anti-Fouling Tube For An Inflation-Control Line On A Parachute”; and U.S. Pat. No. 4,927,099 patented May 22, 1990 to R. C. Emerson et al and assigned to DeCel Incorporated on an “Aerodynamic Controllably Vented Pressure Modulating Drogue”; and U.S. Pat. No. 5,174,527 patented Dec. 29, 1992 to A. D. Kasher and assigned to Alliant Techsystems Inc. on an “Annular Spinning Parachute”; and U.S. Pat. No. 5,360,187 patented Nov. 1, 1994 to J. E. Hengel and assigned to The United States of America as represented by the Administrator of the National Aeronautics and Space Administration on a “Parachute Having Improved Vent Line Stacking”.
SUMMARY OF THE INVENTION
The present invention provides an enhanced pocket band configuration for use with a parachute in order to control and speed initial inflation thereof. This improved parachute design includes a canopy adapted to be inflated to provide controlled descent for a load attached thereto. The canopy preferably includes an inner surface defining an inflation chamber therein and an outer surface about the exterior area thereof oppositely located from the inner surface.
The canopy further includes a lower edge being generally circular in shape and extending peripherally around the parachute. Preferably, a apex opening or canopy vent is defined by the canopy at the uppermost point or apex thereof.
A plurality of suspension lines are attached to the lower edge of the canopy and extend downwardly therefrom for attachment selectively to a load therebelow. A load attachment device such as risers or the like can be attached to the suspension lines in order for detachably securing a load thereto for providing controlled aerial descent thereof.
A plurality of radial lines extend along the canopy from the apex opening or canopy vent to the lower edge thereof. Usually these radial lines are attached to the lower canopy edge at locations where suspension lines also extend downwardly therefrom. The radial lines are attached along the length thereof to the adjacent surface of the canopy. A plurality of gores are defined in the canopy adjacent the lower edge thereof between each pair of the radial lines.
The upper ends of the radial lines terminate at the lowermost edge of the apex opening. Vent lines extend across the apex opening from the lowermost edge thereof. To facilitate distribution of forces, it is preferred than these vent lines be freely movable relative to one another, thus normally they are not secured to one another as they cross over one another in the apex opening area.
A pocket band is attached preferably to the outer surface of the canopy at every gore, or, in some configurations, at every other gore. The means of securement can be by any conventional manner such as adhesives or by being sewn in place to the adjacent members or surfaces. Each of these pocket bands preferably includes a first end fixedly secured to the outer surface of the canopy adjacent one of the gores at an acute angle relative to the radial line secured thereto. The pocket band further also preferably includes a second end fixedly secured by adhesive or being sewn to the outer surface of the canopy adjacent the gore and spatially disposed from the first end and the second end and secured to the canopy preferably at an acute angle relative to the radial line secured at that point.
A central band section of the pocket band is included which can be formed with a width of any reasonable dimension which should be proportional to the parachute diameter. A width of approximately two inches has been found to be preferred for most moderate sized parachutes. This central band section is secured at one end to the first end means and at the other end to the second end means and is not attached in any manner with respect to the canopy such that it is freely movable away from the canopy to enhance forming of an inflation pocket therebetween. The first end and the central band section and the second end of each of the pocket bands can preferably comprise a single integral member of any flexible material, however usually they will be formed of a woven fabric. The central band section is defined to extend between the first end and the second end across an adjacent radial line therebetween and be oriented angularly with respect thereto.
The central band section is preferably movable away from the gore of the canopy to be oriented at an angle extending downwardly and outwardly relative to the radial line thereadjacent in order to facilitate defining of an inflation pocket therebetween. This inflation pocket is designed to receive air moving thereinto during initial inflation of the canopy to facilitate initial deployment thereof. The inflation pocket is adapted to be inflated during the initial inflation of the canopy in such a manner as to urge outward movement of the lower edge of the canopy in order to aid initial inflation thereof. The central band is positioned angularly with respect to the radial line thereadjacent in order to increase the surface area of the central band section oriented perpendicularly to the direction of flow of inflating air during initial inflation of the canopy in order to facilitate defining of the inflation pocket adjacent the gores for more rapidly expanding of the canopy to achieve controlled initial deployment thereof.
The central band section of the pocket band may preferably also include an upper band segment extending between the first end means and the second end means as well as a lower band section also extending between the first and second end means. The lower band segment is preferably of a greater length than the upper band segment in order to allow the central band section to be oriented angularly with respect to the relative direction of movement of air during initial inflation of the canopy. The upper band segment and the lower band segment are preferably formed as a single integral member of woven fabric or other flexible material.
With this construction the central band will preferably be generally of a trapezoidal shape and define a first parallel side and a second parallel side each being parallel with respect to one another with the second parallel side being longer than the first parallel side to facilitate defining of the trapezoidal shape. The first parallel side is preferably positioned on the upper band segment and the second parallel side is positioned on the lower band segment to allow outward flaring of the lower band segment relative to the upper band segment to facilitate defining of an inflation pocket adjacent the lower edge of the canopy for the purposes defined above.
First angular stitching is preferably included for attaching of the first end to the canopy at an acute angle relative to the radial line thereadjacent to facilitate orienting of the central band section angularly relative to the movement of the inflating air. This configuration is for the purpose of urging inflation of the inflation pocket thereadjacent during initial inflation of the canopy. The first angular stitching will preferably include a first inner stitching seam immediately adjacent the central band section and basically forming the interface between the central band section and the first end. In this manner the first inner stitching member will facilitate orientation of the central band section relative to the radial lines at an angle in order to increase the lifting force vector thereon resulting from air movement relatively parallel to the radial lines during initial inflation of the canopy and prior to full inflation thereof.
In a similar manner, a second angular stitching will preferably be included for attaching the second end to the canopy at an acute angle relative to the radial lines to facilitate orienting of the central band section angularly relative to the movement of inflating air in order to urge inflation of the pocket thereadjacent. The second angular stitching preferably includes a second inner stitching seam immediately adjacent the central band section to facilitate orientation thereof angularly relative to the radial lines to increase the lifting force vector thereon resulting from air movement relatively parallel to the suspension lines during initial inflation of the canopy and prior to full inflation thereof. For stability, it is preferable that the pocket band and the angular attachment, which may comprise stitching, forming the pocket band be oriented symmetrically about the adjacent radial line, when viewing radially inwardly thereon.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein inflation pockets are more easily formed at each parachute gore to facilitate canopy inflation.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein conventional parachute materials can be utilized.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein the bands themselves can be secured to the canopy of the parachute by conventional attachment methods such as using adhesives or utilizing stitching to achieve an enhanced unique configuration.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein the reliability of operation of the pocket bands is significantly improved.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein the skirt diameter of the canopy is restricted as with conventional pocket bands to increase effectiveness of the extended skirt.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein initial inflation of the canopy of the parachute is more consistent and uniform.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein use with any number of gores or suspension lines is made possible.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein use with different configurations of canopies is possible.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein the amount of air intersecting the pocket band during initial inflation is significantly increased.
It is an object of the present invention to provide a parachute with enhanced pocket bands to facilitate controlled initial inflation thereof wherein the cross sectional area of the pocket band perpendicular to the relative direction of movement during inflation of the canopy is significantly increased.
BRIEF DESCRIPTION OF THE DRAWINGS
While the invention is particularly pointed out and distinctly claimed in the concluding portions herein, a preferred embodiment is set forth in the following detailed description which may be best understood when read in connection with the accompanying drawings, in which:
FIG. 1 is a side view of an embodiment of the parachute of the present invention shown with the canopy thereof fully inflated;
FIG. 2 is a perspective illustration of an embodiment of the pocket band of the inflated parachute of the present invention showing an enhanced pocket band configuration taken along lines 2 — 2 of FIG. 1;
FIG. 3 is a perspective illustration of the embodiment shown in FIG. 2 with the central band section of the pocket band moved away from the lower outer surface of the partially inflated canopy in order to define an inflation pocket therebetween;
FIG. 4 is a side plan view of an embodiment of the present invention with a partially inflated canopy showing the pocket band spaced from the lower edge of the canopy;
FIG. 5 is a side view of an embodiment of the present invention with a partially inflated canopy showing an inflated pocket band adjacent a gore;
FIG. 6 is an exploded front plan view of an embodiment of a pocket band of the present invention showing attachment to a canopy;
FIG. 7 is a schematic illustration showing the operation of the pocket band of the present invention shown in relation to the canopy skirt and in relation to the relative air flow thereagainst during initial inflation;
FIG. 8 is an illustration of the embodiment shown in FIG. 2 with the pocket band moved to the non-operating position in abutment with the outer surface of the canopy;
FIG. 9 is a cross-sectional view of FIG. 10 taken along line 9 — 9 ;
FIG. 10 is a cross-sectional view of FIG. 1 taken along lines 10 — 10 ;
FIG. 11 is a cross-sectional view of FIG. 1 taken along lines 11 — 11 ;
FIG. 12 is a illustration of an embodiment of the present invention taken from above the canopy with the pocket bands removed to show the vent means for purposes of illustration only; and
FIG. 13 is an illustration of a prior art pocket band shown with the pocket bands attached to the outer surface of the canopy at a gore thereon with the attachment means oriented parallel to the incoming air and the suspension lines thereadjacent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides a parachute 10 with a canopy 12 which is generally circular. Canopy 12 defines an inner surface 14 which defines an inflation chamber 18 therein and an outer surface 16 oppositely positioned from the inner surface 14 .
A lower edge 20 is defined along the bottommost area of canopy 12 and a plurality of radial lines 23 are secured to the canopy 12 . Radial lines 23 extend from apex opening or canopy vent 13 to the lower edge 20 and define gores 24 therebetween. Suspension lines 22 are attached to radial lines 23 and extend past the lower edge 20 of the canopy. A load attachment means 26 which can comprise risers can preferably be located therebelow and be attached to the lower portion of suspension lines 22 . Load attachment means or risers 26 can be detachably securable to a load 27 for providing controlled aerial descent thereof. Use of the load attachment means 26 is optional since the suspension lines 22 can be secured directly to a load 27 under in certain applications of the parachute system of the present invention.
The canopy 12 includes the plurality of radial lines 23 extending from the canopy vent or apex opening 13 to the lower edge 20 thereof. A vent 13 can be located in canopy 12 in the areas of the apex 19 or uppermost location thereon. A plurality of gores 24 are included each located between adjacently positioned radial lines 23 and extending therebetween. Suspension lines 22 are attached to each radial line 23 at the canopy lower edge 20 and extend downwardly therefrom. The individual radial lines 23 and the specifically associated suspension line 22 can each be constructed as a single integral line in some parachute designs without affecting the function of the present invention.
In the preferred configuration of the present invention a pocket band 28 is secured by adhesive or stitching to the outer surface 16 of the canopy 12 of the present invention in such a manner as to extend over the radial line 23 secured thereadjacent. This pocket band 28 preferably includes a first end 30 secured to the outer surface 16 of the canopy 12 and a second end 32 secured to the outer surface 16 of the canopy 12 on the opposite side of the radial line 23 from the first end 30 . Thus, with first end 30 secured to the canopy 12 on one side of the radial line 23 and the second end 32 secured on the opposite side thereof, the pocket band 28 will extend across radial line 23 secured to the lower edge 20 of canopy 12 .
The first end 30 and the second end 32 of the pocket band 28 of the present invention are connected with respect to one another by a central band section 34 . It is this central band section 34 which extends from the gore 24 on one side of the radial line 23 to the adjacent gore 24 on the other side thereof. In this invention the central band section 34 will be oriented vertically at an angle relative to the radial lines 23 and with respect to the canopy 12 . This angular orientation is for the purpose of having the central band section 34 provide a greater cross section of wind resistance which is impinged upon by the relative upward movement of air with respect thereto during inflation.
As best shown in FIGS. 6 and 7, air will force the pocket band 28 away from the lower edge 20 of canopy 12 when the pocket band 28 is in close proximity to the lower edge 20 during the initial stages of inflation. At this point, the aerodynamic forces are helping to move the pocket band 28 away from close contact with the lower edge 20 of canopy 12 so that the pocket band 28 will assume the orientation shown in FIGS. 3 , 4 , and 5 , and still later, will assume the orientation shown in FIG. 2 after the canopy becomes fully inflated. The angle of the adhesive attachment or stitching 38 and 42 will help to orient the pocket band 28 as shown in FIG. 3, thus avoiding the undesirable orientation shown in FIG. 8 . For the purpose of this preferred embodiment only, stitching 38 and 42 will be described as the means of attachment of the pocket bands 28 to the adjacent surface but attachment utilizing standard adhesives used in this field of art is also within contemplation of the present invention. As a result of this geometry when the pocket band 28 is in close proximity to the lower edge 20 as shown in FIG. 8, the aerodynamic forces are not effective in moving the canopy 12 radially outwardly for encouraging full inflation thereof. As the pocket bands 28 move as shown in FIGS. 4 , 5 and 6 , they will be stretching outwardly due to the aerodynamic forces. Tension will then be applied to canopy 12 by pocket bands 28 thereby urging the lower edge 20 of canopy 12 to move radially outwardly. The angled stitching 38 and 42 serves to promote this specific function of each pocket band 28 .
In order to angularly orient the pocket band 28 and, in particular, the central band section 34 thereof relative to the canopy 12 and the radial lines 23 and the relative air direction movement 48 , a first angular stitching 38 is utilized. The configuration of this stitching is shown best in FIG. 6 and makes use of a first inner stitching seam 40 at the intersection between the central band section 34 and the first end 30 . In a similar manner a second angular stitching 42 is utilized at the second end 32 for securement thereof with respect to the canopy 12 and utilizes a second inner stitching seam 44 angularly oriented relative to the lower edge 20 of the canopy 12 in order to encourage movement of the central band section 34 away from abutment with the lower edge 20 of the canopy 12 to facilitate defining of the inflation pocket 29 relative to the outer surface 16 of canopy 12 .
With this stitching configuration of the first inner stitching seam 40 and second inner stitching seam 44 , the central band section 34 will be formed in the general shape of a trapezoid 46 . This trapezoidal shape 46 will include a first parallel side 58 along the upper band segment 54 of the central band section 34 . In a similar manner the trapezoidal shape 46 will dictate the lower band segment 56 of the central band section 34 to define a second parallel side 60 . First parallel side 58 will be smaller than second parallel side 60 thereby causing an angle 36 to be created between the adjacent radial line 23 and the inner stitching seams 40 and 44 . This configuration for the pocket band 28 will encourage the lower band segment 56 of the trapezoidal shaped central band section 34 to flare outwardly and assume an acute angle 52 in relation to the relative direction of movement of air shown by arrows 48 to enhance the possibility of immediate full inflation of an inflation pocket 29 adjacent each of the gores 24 .
The vertical or lateral dimension of the pocket band is critical because it is this dimension which determines the cross sectional area against which the relative air flow 48 will contact. The width or vertical height 50 of the pocket band 28 is preferably approximately two inches. The width of the band 28 can be much wider than two inches for larger canopy diameters and can be much narrower for smaller ones. However, the relationship between canopy size and the width of band 28 is an important aspect of the present invention.
A prior art configuration is shown in FIG. 13 wherein the prior art pocket band 62 is shown along a prior art lower canopy edge 64 adjacent a prior art suspension line 66 . With this configuration it can be seen that the inner seam of the stitching on each end of the pocket band is parallel with respect to one another and parallel to the radial lines and the direction of movement of air during initial inflation thereof. Also, this stitching, which is perpendicular to the lower edge of the canopy, defines a central band section of the pocket band which is rectangular in shape rather than trapezoidal and thereby is not oriented angularly with respect to the radial lines as in the present invention. For this reason the present invention is a distinct improvement thereover for the reasons described above regarding the advantages of the angular relationship of the central band section 34 relative to the direction 48 of relative inflating air movement.
In summary, the angled stitch pattern of the present invention orients the pocket band in such a manner as to be angularly oriented relative to the radial lines defining the canopy profile. The pattern also provides this angular relationship relative to the canopy skirt and, most importantly, relative to the air flow during initial stages of inflation. This angular orientation generates a lift component that will force the canopy skirt outwardly in order to more rapidly and reliably inflating the canopy skirt. This is achieved by the force exerted on each pocket band outwardly and away from the canopy which allows the pocket band to have a propensity to assume the configuration shown in FIG. 3 much more often than assuming the collapsed configuration shown in FIG. 8 .
As shown in the figures, the detailed structure of the apparatus of the present invention includes radial lines 23 which are the structural members that transfer loads from suspension lines 22 into the canopy 12 . Radial lines 23 are secured to the fabric portion of canopy 12 , and generally extend from the lower edge 20 thereof to vent 13 . The band extending about the edge of the vent is the member in combination with the overall canopy configuration and the radial lines together distribute the load along the desired paths. It should be appreciated that in accordance with the present invention, it is contemplated that the radial lines 23 the suspension lines may be separate elements or may each comprise a single integral member or continuous line. Each gore 24 is separated from an adjacent gore 24 by a radial line 23 . The lowermost section of a gore 24 is defined by canopy lower edge 20 .
While particular embodiments of this invention have been shown in the drawings and described above, it will be apparent, that many changes may be made in the form, arrangement and positioning of the various elements of the combination. In consideration thereof it should be understood that preferred embodiments of this invention disclosed herein are intended to be illustrative only and not intended to limit the scope of the invention.
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A parachute with enhanced pocket bands positioned adjacent the points of securement of suspension lines and radial lines with respect to the lower edge of the canopy of the parachute wherein the pocket bands are oriented angularly with respect to the radial lines and with respect to the direction of flow during initial inflation of the parachute in order to enhance inflation of air pockets between the pocket bands and the external surface of the canopy adjacent the radial lines in order to more rapidly inflate the canopy of the parachute to facilitate use thereof at lower altitudes and to provide a more controlled canopy inflation. Pocket bands are attached to the lower canopy edge at an angular relation thereto such that the bands catch significantly more air than in the prior art design in order to facilitate inflation of the pocket bands and achieve rapid controlled inflation.
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OVERVIEW OF INVENTION
[0001] 1. Technical Field
[0002] The present disclosure relates generally to apparatus, systems and methods for attachment of an object to a hard point on an vehicle. In particular, the present disclosure relates to apparatus, systems and methods for attachment of an external payload or store to a hard point on an air vehicle, such as an Unmanned Aerial Vehicle (UAV).
[0003] 2. Background
[0004] The current art exists for attachment of an external payload to a hard point of a vehicle, specifically, a UAV, that consists of a multi-screw pattern on the payload which matches up with the same screw pattern on the hard point of the UAV. The screw pattern of the external payload, with the aid of alignment pins, is brought into alignment with the screw pattern on the UAV hard point, and the screws are tightened to a predetermined torque in order to mount the payload to an external surface of a UAV. This method requires aligning and holding the payload in a fixed location while the screws are tightened. Additionally, typically, the attachment screws are threaded into locking helicoils which are designed to prevent the hardware from loosening and backing out during flight. These helicoils may only be used for a limited number of cycles and must be regularly replaced.
[0005] Therefore, an improved method of attaching an external payload to a surface of an aerial vehicle is needed that can easily be incorporated into the structure of the aerial vehicle, that allows for quick and easy upload and download of a payload.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is an iso-metric view showing an embodiment of the attachment apparatus, and
[0007] FIG. 2 is a side plan view showing an embodiment of the attachment apparatus, and
[0008] FIG. 3 is an exploded view showing an embodiment of the attachment apparatus.
DETAILED DESCRIPTION OF INVENTION
[0009] Embodiments in accordance with the present disclosure are set forth in the following text to provide a thorough understanding and enabling description of a number of particular embodiments. Numerous specific details of various embodiments are described below with reference to attachment of payloads to an aerial vehicle, but embodiments can be used with other features. In some instances, well-known structures or operations are not shown, or are not described in detail to avoid obscuring aspects of the inventive subject matter associated with the accompanying disclosure. A person skilled in the art will understand, however, that the invention may have additional embodiments, or that the invention may be practiced without one or more of the specific details of the embodiments as shown and described.
[0010] Referring to FIGS. 1 , 2 , and 3 which depicts a store/payload attachment device 10 . Typically, the attachment device 10 would be mounted by a plurality of threaded retainers 42 or the like to the inside structure or skin of the vehicle (not shown). For clarity, the vehicle skin and structure has been removed, but such mounting is well known in the art. The attachment device 10 is comprised of a housing 12 which includes an elongated base 15 and located at a first distal end of the base 15 is a retention receptacle 14 and disposed at the other distal end of the base 15 is a release receptacle 18 . The retention receptacle 14 is a tubular like structure that is sized to receive a payload pin 16 a which is protruding upwardly from the surface of a payload 16 . A slot 24 is disposed on the payload pin 16 a which is configured to align with an opening 46 disposed on the receptacle 14 when the pin 16 a is fully inserted up into the receptacle 14 .
[0011] The release receptacle 18 is a tubular like structure that is configured to slidably receive and retain a release mechanism assembly 20 . An elongated slot 19 disposed in the receptacle 18 is configured to engage pins 20 a and 20 b protruding from the release mechanism assembly 20 to guide the motion of the release mechanism 20 when it is moved in an up and down like motion. A d-ring 22 is disposed at a lower distal end of the release mechanism 20 which allows a person to grab onto and pull down on the release mechanism 20 .
[0012] Release mechanism 20 consists of shaft 60 possessing a hole to receive D-ring 22 at the lower distal end and hole 68 to receive pin 62 at the upper distal end. Pin 61 slidably engages shaft 60 through hole 65 and fixedly engages pin 62 through hole 64 . Bushings 63 and collar 67 are rotably engaged by pin 62 and slidably constrained by the collar of shaft 68 and the head of pin 62 . The diameters of pin 62 , collar 67 and collar of shaft 60 are of such size that they slidably and rotably engage the inner surface of receptacle 18 .
[0013] An elongated slot 66 disposed in the receptacle 18 is configured to engage pin 61 protruding from the release mechanism assembly 20 . Slot 66 possesses a “J” configuration such that shaft 60 with pin 61 slidably engaged in slot 66 may be rotated and pin 61 received into the short leg slot 66 's “J” so as to hold release mechanism assembly in an “open” position. Twisting and releasing shaft 60 will cause the release mechanism assembly 20 to retract through the force provided by the spring 34 .
[0014] A spring loaded locking pin assembly 21 is disposed between the retention receptacle 14 and the release receptacle 18 and is comprised of a lock pin 26 having a tapered end 44 and a collar 28 disposed on one distal end. A spring 34 is disposed around the lock pin 26 and abuts the collar 28 to provide a locking biasing force. A bushing 48 is disposed at the other distal end of the lock pin 26 and is configured to slidably engage the lock pin as it is moved between a locked and unlocked position. The bushing 48 engages clevis 50 on the release receptacle 18 . Bushing 48 is captured by cap 51 , which is attached to clevis 50 by screws 51 .
[0015] An L-shaped bellcrank link 32 is pivotably attached to the base 15 at first pivot 36 . Disposed at one distal end of the link 32 is an elongated slot 17 which is configured to interface with a pin 20 b which protrudes from release mechanism 20 such that when the release mechanism 20 is pulled in a downward direction, the link 32 rotates about the first pivot 36 . A first link 30 is pivotably disposed between link 32 and extends to the collar 28 at a second pivot 38 such that when the link 32 rotates in a clockwise direction, the lock pin 26 slidably retracts from the retention receptacle 14 . With this arrangement, pulling down on the d-ring 22 will rotate the link 32 which will pull the lock pin 26 tapered end 44 out of the retention receptacle 14 and either allows the payload pin 16 a to be removed from or inserted into the retention receptacle 14 .
[0016] The spring 34 is configured to force the tapered end 44 through the an opening in the retention receptacle 14 and through the slot 24 in the pin 16 a and into the opening 44 such that the wedge like action of the tapered surfaces positively retains the payload 16 with no clearance or slop.
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A method and apparatus for attachment of a payload/store to the external surface of an aerial vehicle is disclosed. The method and apparatus comprises a single point release feature that simplifies the installation and removal of the payload.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a solid fuel stove, especially for indoor use. More particularly, the stove is especially adapted for loading of either coal or wood sections, or both, through openings at the front and side or end of the stove, respectively, each of which is provided with an appropriate hinged door.
2. Description of the Prior Art
Metal stoves for burning of coal or wood have long been known in the art. For instance, the following patents illustrate stoves embodying various features of construction, including a hinged stove door with mica windows, fireboxes with cast iron liners, rotatable grates, sectional structures, draft controls and baffles and are illustrative of the state of the prior art:
______________________________________ 30,074 - Sept. 18, 1860 400,481 - April 2, 1889116,768 - July 4, 1871 501,885 - July 18, 1993129,020 - July 16, 1872 629,544 - July 25, 1899129,711 - July 23, 1872 1,645,244 - Oct. 11, 1927201,255 - March 12, 1878 1,827,046 - Oct. 13, 1931216,708 - June 17, 1879 4,027,649 - June 7, 1977283,790 - Aug. 28, 1883 D-237,798 - Nov. 25, 1975______________________________________
However, these prior art patents reveal certain shortcomings, inasmuch as as none of these patents discloses the combination of a front door and associated draft control which is used primarily when burning coal and an end door for facilitating insertion of relatively long sections of wood, combined with an ash pit door, draft control and grate rotating components. Moreover, a disadvantage commonly found in existing stoves is collection of ashes on the grate, a circumstance which necessitates frequent cleaning during operation and causing considerable inconvenience to the users of the stove. Furthermore, build up of ash residue beneath the grate can lead to reduced air circulation, require frequent emptying of ashes and create further inconvenience to the stove operators. Conventional solid fuel stove doors are made from solid sheet cast metal, precluding visual observation of the progress of combustion within the stove. Alternatively, the stoves have portholes or vents, which leads to undesirable heat loss through drawings of air into the combustion chamber, or expulsion of combustion products into the ambient surroundings.
SUMMARY OF THE INVENTION
The disadvantages of the prior art constructions of wood or coal burning stoves have been overcome with the present invention through the combination of a substantially rectangular metal stove of somewhat greater width than depth, the stove front having a hinged door with an opening covered by mica sheets for visual observation of the combustion zone, with the front door permitting introduction of lumps or chunks of aggregate solid fuel, such as coal, and with a side door allowing introduction of sections of elongated solid fuel, such as logs of wood.
A shaker grate, preferably made of cast iron and rotatable so as to give the user a choice of grate position adapted for either burning wood, or, by rotating the grates from the outside, for burning of coal. With use of the shaker grate, it is furthermore possible to reduce ash build up by imparting reciprocating to it from the outside, thereby causing ashes generated during use of the stove to be deposited downwardly from the combustion zone into an ash drawer for accumulation and subsequent removal. The ash drawer is accessible for ash removal through a hinged ash door located beneath the side door. The ash door has mounted in its face an adjustable type cover or bell draft for control of incoming combustion air, and also allows access beneath the grates to facilitate ash removal.
Inside the stove a scoop-shaped baffle is mounted immediately below the flue passage opening to restrict the flow of flue gases and to indirectly divert unburned gases back toward the direction of burning fuel. Cast iron replaceable liners are provided around the combustion zone to confine the combustion zone over the grates and protect the side and end walls of the stove.
Accordingly, an important object of the invention is to provide a solid fuel stove adapted for burning either aggregate solid fuel, such as coal and the like, or elongated solid fuel sections, such as wood logs.
Another object is to incorporate into the stove a grate rotatable externally, thereby to give the stove user the capability of adapting the grate configuration to the type of solid fuel chosen.
Still another object is to permit direct visual observation of burning contents of the stove through a transparent refractory window, such as a sheet of transparent mineral, for example, mica.
Yet another object is to provide for convenient ash removal from the stove, and to maximize the period of stove use between ash cleaning operations.
A further object is to improve fuel efficiency by providing internal baffling to direct gaseous combustion products back toward and into the combustion zone.
These, together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the present invention, showing the initial section of exhaust gas flue in phantom.
FIG. 2 is a fragmentary perspective view of the stove, showing all hinged doors in the opened position, thereby permitting a partial view of inside components.
FIG. 3 is a transverse sectional view of the stove of the present invention, taken substantially upon a plane passing along section line 3--3 on FIG. 1, and showing patterns of internal gas circulation of gaseous products of combustion inside the stove by means of arrows, and further showing details of the internal components of the stove, including the rotating grates, grate ridge, ash drawer, firebox liner, flue baffle, and other components.
FIG. 4 is a longitudinal sectional view of the stove, taken substantially upon a plane passing along section line 4--4 on FIG. 3, and showing further details of the internal components thereof.
FIG. 5 is a top sectional view of the stove of FIG. 1, taken substantially upon a plane passing along section line 5--5 on FIG. 1, giving a top plan view of internal components.
FIG. 6 is a group perspective view of the transparent window and screen arrangement for the front door of the stove shown in FIG. 1.
FIG. 7 is a fragmentary enlarged sectional view of a joint between panel sections of the stove of FIG. 1, showing the insulating means therebetween.
FIG. 8 is an exploded perspective view of certain internal components of the stove of FIG. 1, showing the relationship and association of the base, ash drawer, rotating grates, grate ridge, firebox liners, front opening, front door, side and rear wall panels, flue baffle, firebox roof, and other associated components.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The stove of the present invention, designated in the drawings generally by the numeral 10 is made of individual sections having overlapping ridges and grooves which are filled with an insulating material, preferably of a refractory material, such as asbestos cement. The individual sections are preferably made from a heat-resistant metal, such as cast iron, although sections of other materials, such as sheet steel, refractory blocks, coated or galvanized iron, or other well known materials, either cast or fashioned by other means, such as by stamping, molding, casting, bolting, clamping, or the like, can also be used for some or all components of the invention. These sections making up stove 10 include front section 12, side section 14, back section 16, base section 18, firebox roof 20, and crown 22, which is provided with a decorative ornament 24 including ring 26, which can be used for lifting if desired. Hinged front door 28 is attached to front section 12 by hinges 30, front door 28 turning about rivets 31 placed in hinges 30, cast into or welded to front door 28, and in receptacles 32, cast into or welded to front section 12. Front door 28 is provided with front door opening 34, which comprises a pair of cast iron frames 36, into the inner one of which are placed mica sheets 38, held in place by screen 40 and outer cast iron frame 36, as best seen in FIG. 6. Front door 28 is provided with front door handle 40 for opening front door 34 when kindling a fire in stove 10 or introducing fuel, such as coal, through front opening 42. Below front door 28 is front convex panel 44, on which is centrally placed bell draft 46 for adjustably admitting air into the stove. Panel 44 is provided with an air inlet opening 48, as best seen in the illustration of a similar bell draft 46 located on ash door 47, FIG. 8. The threaded wing nut 50 fits into a threaded hole in panel 44 drawing bell 52 in closer proximity to opening 48 and thereby restricting the flow of air.
Side door 54, also provided with a bell draft 46, is particularly useful for introducing sections of wood, such as logs of appropriate size and length, into the combustion zone of stove 10. Opening of hinged side door 54, mounted on side panel 56 by hinges 58, is facilitated by handle 60, which is similar in construction and purpose to handle 40 on front door 28. Front panel 12, rear panel 16, and side panels 14 and 56 are mounted upon base 18 which also supports the grate structure and firebox liner. The grate structure and firebox liner are mounted upon ash drawer 62, which rests upon base frame 64 and mounts rotating grates 66 in recesses 67' of panel 68' placed at the end opposite side door 54, and below support bracket 70, at the end nearest to side door 54. Panel 68' is secured to ash drawer 62 by bolts 69', recesses 67' fitting into recesses 67 of ash drawer 62. Grates 66 extend from side to side in substantially parallel configuraion and in the longest dimension of stove 10, thereby facilitating burning of segments of wood, such as logs of appropriate diameter and thickness. Grate ridge 68 is placed between grates 66, secured to bracket 70 by bolt 71 and secured to panel 68' by means of bolt 73' placed through flange 73. When grates 66 are to be used for burning of wood, they will preferably be used in the configuration of FIG. 3, with support of generally parallel burning logs being afforded by the upper ridge of grates 66, as well as by the upper edges and surfaces of grate ridge 68. In such a configuration, the gap between lateral edge 69 of grate ridge 68 and scalloped surfaces 72 of grates 66 is maximum for permitting maximum upward draft air and facilitating downward ejection of ash particles into ash drawer 62. Rotation in reciprocating motion of grates 66 can be used for dislodging and dropping of ash particles from the combustion zone, such rotation being conveniently effected with use of detachable crank 74, having socket end 76 with a recess (not shown) compatible with projecting square end 78 of rod 80 centrally and longitudinally disposed along grate 66. Scalloped surfaces 72 of grate 66 can be oriented with respect to fixed grate ridge 68 by either clockwise or counterclockwise rotation through 45 degrees from the position shown in FIG. 3. In such a configuration, edge 82 of grate 66 will be placed in close proximity to grate ridge 68, thereby leavinga minimum gap therebetween for retention of relatively small particles of combustible material, such as lumps of coal. Such rotation is also facilitated by use of crank 74. The entire combustion area is surrounded by firebox liner 84, which comprises preferably cast iron replaceable liners which serve to confine the burning area over grates 66, and further serve to protect side, front and end panels 14, 56, 12 and 16 from the deleterious effects of direct exposure to the fire in the combustion zone. Firebox liner 84, best seen in FIG. 8, is composed of horizontal reinforcement ribbing on side firebos liner sections 86, horizontal reinforcement ribbing on back firebox liner 88, and vertical ribbing for front firebox liner 90. A smoke curtain 57 can also be welded or otherwise attached to side panel 56 to prohibit excessive smoke from leaving stove 10.
The gaseous combustion products follow a circulation pattern inside stove 10 best seen in FIG. 3 from the directions of arrows representing general flow lines for hot combustion products. Scoop-shaped baffle 94 deflects gases rising upwardly from the region inside firebox liner 84 to divert any unburned gases forwardly and assist in drawing such gases back towards the burning fuel. This promoted more thorough and complete combustion, and leads to greater fuel efficiency. Moreover, baffle 94, mounted immediately below flue passage opening 96, restricts the flow of flue gases and further promotes full combustion thereof. Cast into the upper back section, and into the rear of roof 20 are matching one-half sections 98 of oval collar, which when both parts are matched and bolted form a connecting collar on which smoke pipe connection 100 is mounted. A standard smoke pipe is used to exhaust the products of combustion.
Individual sections of stove 10, such as side section 56 and side door 54 are fitted together with overlapping ridges and grooves which are cast into the individual parts. The interlocking sections are sealed with asbestos type or other high temperature cement, such as strip 102, as best seen in FIG. 7.
Ash door 47 is conveniently opened with the use of conventional handle 106 for removal of accumulated ashes 107 in ash drawer 62. Ash door 47 is mounted by hinges on hinge collars 108 on ash frame 110. Frame 110 is provided with bearing holes 112, through which rods 80 of grates 66 pass and are supported. A suitable indentation 114 in base frame 64 allows for fitting of ash drawer 62 as well as frame 110. Base frame 64 is also provided with appropriate legs 116 for support thereof.
Preferably, sections of stove 10 are made from cast metal, such as cast iron. Overlapping ridges and grooves cast into the individual parts provide for interlocking cast iron sections fitted together and sealed with asbestos type or other high temperature cement.
Although the present invention can be constructed in a wide variety of shaped and sized without departing from the essential nature of the invention, such varying constructions being contemplated within the scope of the invention, in a typical preferred embodiment, the stove has approximate dimensions of 30 1/2 inches in height, 22 inches in depth, and 26 inches in width, giving a shipping weight of approximately 319 pounds and permitting logs having a length up to 21 inches to be burned. This stove is also adapted for use with coal, such as grades of coal particularly suitable for combustion and indoor stove, such as cannel coal, a bituminous coal containing considerable volatile matter which burns brightly.
It is of particular importance that in one embodiment of the invention the combination of rotating grate for adapting the combustion zone for supporting either coal or wood by adjustment of the grate, front door for loading and distributing coal along the longitudinal extent of grates, and side door for loading of long wood, be all present together in a single stove, as taught by the present invention. With this combination, the best conditions of combustion of either selected solid fuel is obtained without the necessity for internal adjustments or even the necessity for cooling of the stove for conversion from coal to wood or wood to coal. This flexibility renders apparent the advantage in a typical situation of use where the supply of either coal or wood might be limited, such as by storage capacity, and where conversion from one to the other is expectable during use. Accordingly, with the present invention, it is possible to reduce the storage supply of fuel, such as coal, inasmuch as a more readily available source of wood fuel can be easily substituted without requiring the stove and ambient indoor surroundings to cool prior to conversion.
Moreover, the combination of the particular rotating grate, ash drawer and mica window of the present invention are distinguishing features from prior art stove combinations, offering advantages of convenience in use, improved performance and greater fuel efficiency, and improved observation and control of the operation of the stove.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A solid fuel stove is disclosed having a hinged door adapted for loading of aggregate solid fuel in the form of lumps or chunks, such as coal, and a second hinged door located at the side or end of the stove, adapted for loading of elongated sections of long solid fuel, such as sections of wood. The stove further includes a third hinged door for cleaning out ashes, and a scoop-shaped baffle for restricting the flow of flue gases and diversion of unburned gases back into the combustion zone. Cast iron liners confine the burning area and protect the stove walls, and oval collar sections connect the upper back section of the stove with a conventional smoke pipe for exhausting the products of combustion.
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CROSS-REFERENCE TO RELATED U.S. APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
Not applicable.
REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic cabinet lock which has been developed to be used in drawers and cabinet doors (covers) made of metal, wood or plastic materials.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
In the electronic lock systems used in the prior art, a microprocessor checks the validity of the commands entered by means of a keypad and performs the required functions. For instance, it allows checking the authenticity of the entered password and performing the opening process provided that the password is correct or changing the program parameters of the lock etc.
A password is required to be entered to be able to realize all the processes. It is necessary to enter a user or master password for the processes such as opening/closing, password-change, and parameter-change.
In order to change the program parameters, it is required to enter the master password first and then the parameter intended to be changed and the option thereof. This process needs to be repeated for each parameter. Therefore, the operational parameter adjustment of the locks is time-consuming and brings along excessive burden in the places where the number of locks is significantly high. Additionally, since each password-entering action causes battery consumption, it reduces the battery life and thus increases the waste batteries.
As a result of the patent search, the American patent application numbered U.S. Pat. No. 9,495,898B2 has been encountered. The disadvantages of the lock disposed in this application and of the other existing locks are specified below:
The handle used in the existing electronic cabinet locks performs only the opening and closing functions. It has no other function. It mostly has a round/circular shape. The existing electronic cabinet locks have a 6×2 matrix key layout (6 rows and 2 columns). Therefore, other people looking from a certain distance can easily detect the entered password. This in turn causes a security gap. In general, the keypads are universal 4×3 matrix (4 rows and 3 columns). The phone keypads which have been widely used for many years and become standardized are 4×3 matrix. As 6×2 matrix configuration is non-standard, the use thereof is not ergonomic and it has inconveniences such as memorizing and entering the password. The lock body of the existing electronic cabinet locks is cone-shaped. That is to say, the width of the surface contacting with the door is more than the width of the surface confronting the front side and there are not any lateral protrusions due to the difficulties in molding method. This makes it difficult to use the lock body with the purpose of pulling the cabinet door. The battery cover of the existing electronic cabinet locks is disposed on the unsafe side of the lock body. The battery cover can be easily opened manually which should not be the case for a security product. This in turn causes safety gaps such as stealing the batteries and feeding high voltage from the battery contacts. The electronic circuit (PCB/Printed Circuit Board) containing the electronic circuits of the existing electronic cabinet locks does not comprise a Radio Frequency (RF) antenna configuration. The locking action is realized by rotating the handle toward the body in a standard way. The number of notches on the rotary shaft (allowing locking or unlocking) bearing the rotational motion is maximum two. For this reason, the lock is always rotated only in one direction. Hence, the locking action in the left doors is not toward the body but in the reverse direction and this, therefore, leads to confusion during the opening or closing processes.
In conclusion, due to the abovementioned drawbacks and inadequacy of the existing solutions with respect to the subject matter, it is deemed necessary to make a development in the relevant technical field.
BRIEF SUMMARY OF THE INVENTION
The present invention has been developed being inspired by the existing conditions and aims to solve the drawbacks discussed above.
The objects of the invention are disclosed below.
An NFC (Near Field Communication) antenna is provided on the electronic circuit inside the body. The fact that a contactless information exchange can be carried out in this manner allows the electronic lock to be easily managed. Thanks to the energy harvesting outlet property of the dynamic NFC tag chip provided on the electronic circuit, the electronic lock can be programmed even when a battery is not inserted into the electronic lock. Thanks to the fact that the electronic lock is NFC-compatible, it can communicate with the devices such as NFC-enabled PDA (Personal Digital Assistant), mobile phone, tablet computer, smart clock or the like and thus it can be managed by means of these devices. NFC communication is completed in a very short time when compared to the time consumed for password-entering. Hence, a significant amount of saving on battery consumption within the lock is achieved. This renders the product environmentally-friendly. The handle comprises a socket so as to house a coil antenna therein. Thus, the lock can be used and managed together with RF tags in a contactless manner. The handle comprises a socket so as to house an antenna (strip type) therein. Thus, the lock can be used and managed together with RF tags in a contactless manner. The handle has a structure to be able to move up/down in a way to push a hidden button thereunder. Said button is activated by pushing down the handle and various functions can be performed in this manner. The primary ones of these functions are as follows: waking up the electronic circuit, preparing for card-reading, confirming the functions etc. Hence, the functions increasing the battery consumption are only activated when needed and this contributes to the long battery life.
In order to fulfill the preceding objects, an electronic lock has been developed which is used in the doors, covers or drawers and comprises:
in order to allow closing the door, cover or drawer, a latch which connects the electronic lock with the door frame or the cabinet, a rotary shaft which drives said latch and comprises rotary shaft notches located thereon and having recesses therebetween, a roller in which said rotary shaft is located and which enables the electronic lock to be mounted to the door/cover/drawer, a micro-motor latch which avoids the motion of the rotary shaft by entering into the recesses between said rotary shaft notches or enables the motion of the rotary shaft by coming out of the recesses, a motion transfer member which moves said micro-motor latch upward or downward, a spring gear which is connected to said motion transfer member, a linear motion transfer member which is connected to said spring gear, a worm screw gear on which said linear motion transfer member moves during rotating, a micro-motor which rotates said worm screw gear, a handle which is rotated by the user and connected to the rotary shaft in order to enable said rotary shaft to rotate, an NFC antenna which is provided on an electronic circuit and allows the signals, which contain therein the functions intended to be realized in the electronic lock and administrator password information and sent by means of the software within the NFC-enabled mobile device, to be detected, a dynamic NFC tag chip which is provided on said electronic circuit and connected to said NFC antenna and in which the information, contained by the signals sent by said mobile device and received through the RF wave by means of said NFC antenna, is saved on the memory therein, and which activates the processor by transferring the energy, which it produces from said RF wave by means of the energy harvesting outlet, into the feed inlet of the processor by means of a rectifier, said processor which is connected to the dynamic NFC tag chip; reads the information inside the memory of said dynamic NFC tag chip by means of the software therein and in response to this information, records data again into the memory of dynamic NFC tag chip or activates said micro-motor; and obtains the information suggesting that the handle is in open position or closed position as a result of the contact between the contact points in different positions on the rotary contact and the electronic circuit.
All structural and characteristic features and all the advantages of the invention will be more clearly understood thanks to the following figures and detailed description composed with reference to these figures and for this reason, it is necessary that the evaluation be done by taking into consideration these figures and detailed description.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is the demounted perspective view of the electronic lock according to the invention.
FIG. 2 a is the front two-dimensional view of the electronic lock according to the invention.
FIG. 2 b is the rear two-dimensional view of the electronic lock according to the invention.
FIG. 3 a is the front perspective view of the electronic lock according to the invention.
FIG. 3 b is the rear perspective view of the electronic lock according to the invention.
FIG. 4 a is the front perspective view of the electronic lock according to the invention when mounted to the cover/door.
FIG. 4 b is the rear perspective view of the electronic lock according to the invention when mounted to the cover/door.
FIG. 5 is the drawing where the electronic lock is held by a user when mounted to the cover/door in order to enable the size of the electronic lock according to the invention to be comprehended.
FIG. 6 a is the drawing which illustrates the position of the components, i.e. micro-motor latch, rotary shaft, micro-motor and spring gear, when the electronic lock according to the invention is in open position.
FIG. 6 b is the drawing which illustrates the position of the components, i.e. micro-motor latch, rotary shaft, micro-motor and spring gear, when the electronic lock according to the invention is in closed position.
FIG. 7 is a drawing which illustrates the communication between the mobile device, dynamic NFC tag chip and the microprocessor. In FIG. 7 , the arrow illustrated between the dynamic NFC tag chip and the microprocessor refers to the serial communication between the dynamic NFC tag chip and the microprocessor.
DESCRIPTION OF PART REFERENCES
10 . Handle
11 . Antenna
12 . Antenna socket
13 . Status indicator housing
13 a . Status indicators
14 . Frame
15 . Locked-unlocked indicator
16 . Coil antenna
17 . Rotary Contact
17 a . Contact points
18 . Keypad
19 . NFC antenna
19 a . Dynamic NFC tag chip
19 a 1 . energy harvesting outlet
19 a 2 . busy status indicator outlet
20 . Electronic circuit
21 . Handle button
22 . Handle spring
23 . Micro-motor latch
24 . Rotary shaft
24 a . Rotary shaft notches
24 b . Positioning ball
24 c . Ball compression spring
25 . Micro-motor
25 a . Worm screw gear
25 b . Linear motion transfer member
26 . Spring gear
26 a . Motion transfer member
27 . Battery contacts
28 . Roller
29 . Lock body
30 . Battery
31 . Battery cover
32 . Left/Right Selector Cam
33 . Latch
34 . Processor
35 . Rectifier
36 . Mobile device
37 . Cabinet
37 a . Door
The drawings do not need to be scaled necessarily and the details that are not necessary for the understanding of the present invention may have been ignored. Apart from this, the elements that are at least substantially identical or that have at least substantially identical functions are shown with same numbers.
DETAILED DESCRIPTION OF THE INVENTION
Within this detailed description, the preferred embodiments of the lock according to the invention are disclosed only for the better understanding of the subject.
The features of the components comprised by the electronic lock according to the invention are stated below:
The handle ( 10 ) is the component which allows the lock to be used. The antenna socket ( 12 ) is located inside the handle ( 10 ). The handle ( 10 ) further functions as a hidden button since it prevents the handle button ( 21 ) located therebehind from being seen. As the handle ( 10 ) has an elliptical form, the power transfer can be realized ergonomically without any finger slip in order to rotate the handle ( 10 ). Owing to this form thereof, the handle ( 10 ) helps the locked/unlocked position thereof to be realized from a certain distance. The antenna ( 11 ) which is provided on the electronic circuit and is preferably a PCB antenna (antenna type placed on the electronic circuit) or a strip antenna (antenna type connected to the electronic circuit) allows a contactless (RF: radio frequency) information exchange and lock operation. The antenna ( 11 ) is located inside the handle ( 10 ). The status indicators ( 13 a ) are preferably LED and located inside the status indicator housings ( 13 ). The status indicators ( 13 a ) and the components providing energy supply in the event that a battery dies or malfunctions are integrated with the electronic circuit ( 20 ) and provided on the electronic circuit ( 20 ). In this manner, the functionality is provided without any need for additional component. The frame ( 14 ) enables the lock body ( 29 ) to function as a handle. The frame ( 14 ) is semi-inbuilt type. Thanks to the frame ( 14 ), the lock body ( 29 ) is mounted to the cover/door ( 37 a )—where it is applied—in a semi-inbuilt manner. It reduces the protrusion height from the mounting surface thanks to the semi-inbuilt mounting thereof. Moreover, it provides an aesthetic look as it makes the visible volume smaller. Hence, an alternative mounting option is provided for those who mount the lock. The locked/unlocked indicator ( 15 ) shows that the electronic lock is locked or unlocked (position thereof). The locked/unlocked indicator ( 15 ) can change in a synchronized manner with the handle ( 10 ). In this manner, the status information (position) can be provided to the user without consuming energy. The locked/unlocked indicators ( 15 ) can give information to the user when needed by being lightened up with a light from below for a limited time period during position changes or with the purpose of warning. The elliptical form of the handle ( 10 ) facilitates to understand easily whether the lock is open or closed when looked from a certain distance. In safe position, the lock handle ( 10 ) has a visual quality in harmony with the lock body ( 29 ). In unsafe position, however, this harmony is disturbed and warns the user by drawing attention. The coil antenna ( 16 ) is located inside the antenna socket ( 12 ) provided inside the handle ( 10 ) and allows RF communication and RFID card-reading. The rotary contact ( 17 ) enables the processor ( 34 ) to identify the position of the handle ( 10 ). When the handle ( 10 ) is rotated, the rotary contact ( 17 ) also rotates. The processor ( 34 ) obtains the information suggesting that the handle ( 10 ) is in open position or closed position as a result of the contact between the contact points ( 17 a ) in different positions on the rotary contact ( 17 ) and the electronic circuit ( 20 ). A highly cost-efficient position identification can be done owing to the rotary contact ( 17 ). Furthermore, thanks to the rotary contact ( 17 ), the processor ( 34 ) detects a situation where the handle ( 10 ) is exposed to a tricky manipulation and the rotary contact ( 17 ) allows taking precaution for the lock to maintain the safe position thereof. The rotary contact ( 17 ) and the contact points ( 17 a ) eliminate the use of a plurality of switches as in the prior art. Therefore, a serious amount of saving on material cost is achieved. As a result, the world resources are used in lesser amounts and an electronic lock is developed which is not breaks down easily. The keypad ( 18 ) allows entering the password. The keypad layout ( 18 ) is universal. Using 4×3 matrix (4 rows and 3 columns), which is a common and conventional configuration, increases the ergonomics for the user. Besides, it provides an easy usage for the users with big fingers thanks to the arc-like (the axis of the middle column being a little bit above) layout of the rows. In addition, the arc-like layout of the keys makes it difficult to identify the entered password by an outside person. NFC antenna ( 19 ) is connected to the dynamic NFC tag chip ( 19 a ) and enables NFC (Near Field Communication) communication with the mobile devices ( 36 ). The electronic circuit ( 20 ) contains thereon the electronic equipment of the electronic lock. The handle button ( 21 ) allows the handle ( 10 ) to function as a button. The handle spring ( 22 ) allows the handle ( 10 ) to assume the former position thereof when pushed and released. The micro-motor latch ( 23 ) avoids or allows the rotary shaft ( 24 ) to rotate. The rotary shaft ( 24 ) transfers the motion of the handle ( 10 ) to the micro-motor latch ( 23 ). The rotary shaft notches ( 24 a ) allows the positioning of the electronic lock to the left/right doors ( 37 a ). The locking action is realized by rotating the handle ( 10 ) toward the cabinet body in a standard way. The number of rotary shaft notches ( 24 a ) on the rotary shaft ( 24 ) bearing the rotational motion (allowing locking or unlocking) is three. Hence, locking both in left and right doors ( 37 a ) is achieved by rotating the handle ( 10 ) toward the cabinet body. This is determined based on the positions of the left/right selector cam ( 32 ) and rotary contact ( 17 ). The positioning ball ( 24 b ) allows the rotary shaft ( 24 ) to be easily positioned. The ball compression spring ( 24 c ) allows the rotary shaft ( 24 ) to be positioned by means of the positioning ball ( 24 b ). The micro-motor ( 25 ) controls the motion of the rotary shaft ( 24 ) by means of the micro-motor latch ( 23 ). The spring gear ( 26 ) transfers the motion of the micro-motor ( 25 ) to the micro-motor latch ( 23 ). The battery contacts ( 27 ) allow the battery ( 30 ) to contact the electronic circuit ( 20 ). The roller ( 28 ) houses the rotary shaft ( 24 ) therein and allows the electronic lock to be mounted to the door. The lock body ( 29 ) comprises therein most of the components of the electronic lock including the electronic circuit ( 20 ). The frame ( 14 ) placed around the lock body ( 29 ) forms a protrusion outward from the lock body ( 29 ). A comfortable handling is provided by filling the space between the frame ( 14 ) and the door ( 37 a ) with the fingers. This in turn facilitates the cabinet ( 37 ) door ( 37 a ) or the drawer to be opened by being pulled. The battery ( 30 ) enables the electronic circuit ( 20 ) to operate. The battery cover ( 31 ) is the section where the battery ( 30 ) is placed. As the battery cover ( 31 ) is located behind the lock body ( 29 ), it is in the safe section. In this manner, the battery ( 30 ) is prevented from being stolen, changed and manipulated. The left/right selector cam ( 32 ) has a function of adjusting the electronic lock with respect to the left or right cover/door ( 37 a ). The electronic lock can be mounted to the doors ( 37 a ) depending on the way of placing the left/right selector cam ( 32 ) and the position of the rotary shaft notches ( 24 a ) provided on the rotary shaft ( 24 ). The latch ( 33 ) allows locking or unlocking the cover/door ( 37 a ). The energy harvesting outlet ( 19 a 1 ) of the dynamic NFC tag chip ( 19 a ) is connected to the feed inlet of the processor ( 34 ) by means of a rectifier (diode) ( 35 ) and the energy produced by means of the energy harvesting outlet ( 19 a 1 ) is transferred to the feed inlet of the processor ( 34 ) by means of said rectifier ( 35 ). The battery ( 30 ) is also connected to the feed inlet of the processor ( 34 ) by means of a rectifier ( 35 ). Thus, not only the feeds are prevented from overlapping when the output voltages of the battery ( 30 ) and the dynamic NFC tag chip ( 19 a ) are at different levels but also any quiescent current flow from the battery ( 30 ) is avoided when the dynamic NFC tag chip ( 19 a ) is not active. Additionally, the processor ( 34 ) is activated by providing feed inlet to the processor ( 34 ) by means of the energy harvesting outlet ( 19 a 1 ) if any feeding energy cannot be supplied to the electronic circuit ( 20 ) or the battery ( 30 ) dies. The mobile device ( 36 ) is an NFC-enabled device, i.e. mobile phone, smart clock, PDA (Personal Digital Assistant), tablet computer or the like.
The electronic lock according to the invention comprises a processor ( 34 ) which is provided on the electronic circuit ( 20 ) and connected to the dynamic NFC tag chip ( 19 a ). Furthermore, an NFC antenna ( 19 ) integrated with the electronic circuit ( 20 ) is provided on the electronic circuit ( 20 ). In addition, a dynamic NFC tag chip ( 19 a ) is disposed on the electronic circuit ( 20 ). The word “dynamic” means that there is an NFC antenna ( 19 ) connected to the dynamic NFC tag chip ( 19 a ) located on the electronic circuit ( 20 ). The feature of the dynamic NFC tag chip ( 19 a ) is that the dynamic NFC tag chip ( 19 a ) runs thanks to the creation of a voltage on the NFC antenna ( 19 ) by the RF wave created by the phone when said dynamic NFC tag chip runs into an NFC-enabled mobile phone. Also, the sign in said RF wave is taken and transferred to the dynamic NFC tag chip ( 19 a ) by means of the NFC antenna ( 19 ) and written to the memory of the dynamic NFC tag chip ( 19 a ). By processing according to the information on the received sign, a response is sent to the reader device, namely the mobile phone again by means of the NFC antenna ( 19 ).
In the existing NFC-enabled devices, 2 devices are drawn closer to each other and the devices communicate with each other in 13.56 MHz frequency. This communication is realized as follows: a special integration which is called “transceiver” (receiver-transmitter communication device) and has a feature of being both a receiver and a transmitter is provided in both devices. The dynamic NFC tag chip used in the electronic lock according to the invention does not have any feature of being both a receiver and a transmitter. Only when it communicates with an NFC-enabled mobile device ( 36 ) or an NFC reader device comprising a receiver-transmitter communication device therein, it can respond to this device. The dynamic NFC tag chip ( 19 a ) alone cannot send out a sign or signal without a device with said features. The disadvantage for this is that the electronic lock cannot be used with an NFC-compatible card. In order to use the electronic lock, it is necessary to use a receiver-transmitter communication device thereon instead of a dynamic NFC tag chip ( 19 a ) or to wire a circuit with the features of the receiver-transmitter communication device.
The features of the dynamic NFC tag chip ( 19 a ):
Having a memory varying between 512 bytes and 800 kb, Comprising thereon a voltage-producing port, namely energy harvesting outlet ( 19 a 1 ) provided that an RF/NFC-compatible device gets closer, Comprising a port, namely busy status indicator outlet ( 19 a 2 ) informing about the RF communication while performing thereof, Comprising I 2 C (Inter-Integrated Circuit) port, Comprising ports where the antenna connection is realized.
The electronic lock according to the invention uses the memory section and the data written to the memory of the dynamic NFC tag chip ( 19 a ) as a communication means. There is no direct RF communication between the dynamic NFC tag chip ( 19 a ) and the mobile device ( 36 ) (mobile phone). The mobile device ( 36 ) writes data to the memory of the dynamic NFC tag chip ( 19 a ) by means of the software contained therein. And, the processor ( 34 ) writes data to the memory or processes in response to the data registered by the mobile device ( 36 ) by means of the software installed therein and then reads what is written to the memory of the dynamic NFC tag chip ( 19 a ) again by means of the mobile device ( 36 ).
I 2 C communication protocol is used in the dynamic NFC tag chips ( 19 a ). The dynamic NFC tag chip ( 19 a ) can also be connected to the processor ( 34 ) with 2 ports. The advantages of the dynamic NFC tag chips ( 19 a ) when compared to the passive NFC chips are that after entering an NFC area, the dynamic NFC tag chip ( 19 a ) harvests the energy in the Radio Frequency wave and produces voltage at the outlet thereof by means of a pin. The object of the invention is also to use the voltage value at the outlet of the dynamic NFC tag chip ( 19 a ) for the operation of the processor ( 34 ). Furthermore, the dynamic NFC tag chips have outlets with “busy or not” feature, namely busy status indicator outlet ( 19 a 2 ). This outlet is also connected to the processor ( 34 ). If the mobile device ( 36 ) writes data to the memory of the dynamic NFC tag chip ( 19 a ) by means of the software contained therein, the processor ( 34 ) receives this information by means of this port (outlet). When the mobile device ( 36 ) completes the writing process, the processor ( 34 ) reads the data on the memory of the dynamic NFC tag chip ( 19 a ) with the I 2 C port and by reading the data written by the mobile device ( 36 ), performs the functions related to this data. These functions may be changing the operation parameters, changing the opening-closing mode, changing the warning mode etc. Or, for example, the processor ( 34 ) writes certain number of instances happened in the past to the memory of the dynamic NFC tag chip ( 19 a ) and mobile device ( 36 ) reads that data from the memory by means of the software contained therein and obtains information such as the password with which the lock is unlocked 1 hour ago, password change performed 2 hours ago, and wrong password entrance 5 hours ago. That is to say, the retroactive information can be interrogated.
When the mobile device ( 36 ) is drawn closer to the electronic lock, the dynamic NFC tag chip ( 19 a ) transmits the energy (having a value of 3V) which it harvested through the RF wave by means of the NFC antenna ( 19 ) into the processor ( 34 ) through the energy harvesting outlet ( 19 a 1 ). The processor ( 34 ) operates and understands that the energy is coming from the dynamic NFC tag chip ( 19 a ). The processor ( 34 ) then interrogates the “busy or not” port, namely the busy status indicator outlet ( 19 a 2 ) of the dynamic NFC tag chip ( 19 a ). When the busy status of the dynamic NFC tag chip ( 19 a ) ends, the busy status indicator outlet ( 19 a 2 ) changes position thereof and the processor ( 34 ) reads the memory of the dynamic NFC tag chip ( 19 a ) and fulfills the commands (Is it going to operate in the individual use, is it going to operate in the multiple use, is the voice going to be active or passive etc.?) related thereto.
In the preferred embodiment where the dynamic NFC tag chip ( 19 a ) and NFC antenna ( 19 ) are used, if the password entered by the user is correct, the following processes are realized during the opening process of the lock:
The processor ( 34 ) engages—that is to say, activates—the micro-motor ( 25 ), Micro-motor rotates the worm screw gear ( 25 a ), The linear motion transfer member ( 25 a ) on the spring gear ( 26 ) moves on the worm screw gear ( 25 a ) in the opposite of the direction where the micro-motor ( 25 ) is disposed, During said motion of the linear motion transfer member ( 25 b ), the motion transfer member ( 26 a ) connected to the spring gear ( 26 ) moves the micro-motor latch ( 23 ) upward, Upon the downward motion of the micro-motor latch ( 23 ), the micro-motor latch ( 23 ) comes out of the rotary shaft notches ( 24 a ), The user rotates the rotary shaft ( 24 ) toward the opening direction and the cover/door ( 37 a ) or the drawer is opened.
The following processes are realized during the closing process of the electronic lock:
The user rotates the rotary shaft ( 24 ) toward the closing direction, The processor ( 34 ) engages—that is to say, activates—the micro-motor ( 25 ), Micro-motor ( 25 ) rotates the worm screw gear ( 25 a ), The linear motion transfer member ( 25 b ) on the spring gear ( 26 ) moves on the worm screw gear ( 25 a ) in the direction where the micro-motor ( 25 ) is disposed, During said motion of the linear motion transfer member ( 25 b ), the motion transfer member ( 26 a ) connected to the spring gear ( 26 ) moves the micro-motor latch ( 23 ) downward, Upon the downward motion of the micro-motor latch ( 23 ), the micro-motor latch ( 23 ) enters into the recess between the rotary shaft notches ( 24 a ), and the cover/door ( 37 a ) or the drawer is closed thereby.
The processes during opening and closing mentioned above are not new features and have been described in the US patent application numbered U.S. Pat. No. 8,671,723 B2 and filed by the same applicant VEMUS ENDUSTRIYEL ELEKTRONIK SANAYI VE TICARET LIMTED SIRKETI.
The mobile device ( 36 ) performs the following functions on the dynamic NFC tag chip ( 19 a ) by means of the software installed therein:
Changing or reading the program parameters of the electronic lock, Changing the passwords defined in the electronic lock, Reading the incidents happened in the electronic lock, Naming, defining, addressing the electronic lock, Opening, closing the electronic lock.
In the electronic lock according to the invention, provided that the entered password is correct in the electronic lock, the handle ( 10 ) connected to the rotary shaft ( 24 ) released is rotated by the user. The rotary contact ( 17 ) connected to the handle ( 10 ) changes position and contacts the contact points ( 17 a ) on the electronic circuit depending on the new position thereof. The processor ( 34 ) engages or disengages the micro-motor ( 25 ) according to the signs coming from the contact points ( 17 a ).
In the other preferred embodiments of the electronic lock according to the invention, an antenna ( 11 ) or coil antenna ( 16 ) can be provided in addition to the dynamic NFC tag chip ( 19 a ) and NFC antenna ( 19 ) in a manner connected to the electronic circuit ( 20 ). For, NFC antenna ( 19 ) is away from the coil antenna ( 16 ) and they do not affect each other. However, the antenna ( 11 ) and the coil antenna ( 16 ) cannot be located on the electronic circuit ( 20 ) at the same time. It is because the operating frequencies thereof affect the operating thereof.
The embodiment of the electronic lock which comprises a coil antenna ( 16 ) thereon is used with a proximity card containing an RF tag operating in 125 kHz frequency. Said proximity card containing RF tag can also be located inside a key chain, watch, bracelet etc. Since the frequency is 125 kHz, extra wound wire is required. For this reason, the coil antenna ( 16 ) is used. Closing process of the electronic lock which is open in this embodiment is realized as follows. First of all, the handle ( 10 ) is pushed with the proximity card and thus the handle ( 10 ) also pushes backward the handle button ( 21 ) provided therebehind. Upon this pushing action, the processor ( 34 ) detects that there is a contact to the handle button ( 21 ) and the coil antenna ( 16 ) is activated. The processor ( 34 ) reads the information on the RF tag inside the card/key chain by means of the coil antenna ( 16 ). The user enters the password and rotates the handle ( 10 ) preferably within 5 seconds and switches the same to closed position. Provided that the entered password and the password previously-defined on the RF tag are correct, the micro-motor latch ( 23 ) enters between the rotary shaft notches ( 24 a ) with the motion of the micro-motor ( 25 ) and the electronic lock is locked (provided that the password is wrong, it gives an error alert). In order to re-unlock the electronic lock, first of all, the handle ( 10 ) is again pushed by means of the proximity card used during closing of the electronic lock and thus the handle ( 10 ) also pushes backward the handle button ( 21 ) provided therebehind. Upon this pushing action, the processor ( 34 ) detects that there is a contact to the handle button ( 21 ) and the coil antenna ( 16 ) is activated. The processor ( 34 ) reads the information on the RF tag inside the card/key chain by means of the coil antenna ( 16 ). The user enters the password. Provided that the entered password and the password previously-defined on the RF tag are correct, the micro-motor latch ( 23 ) comes out of the rotary shaft notches ( 24 a ) with the motion of the micro-motor ( 25 ) and the electronic lock is unlocked. The user rotates the handle ( 10 ) in the reverse of the closing direction preferably within 5 seconds and switches the same to open position.
The embodiment of the electronic lock which comprises an antenna ( 11 ) thereon that is preferably flexible is operated with an NFC-compatible card containing an RF chip therein and operating with 13.56 MHz. The NFC-compatible card can preferably be a Mifare or DESFire card. Closing process of the electronic lock which is also open in this embodiment is realized in a way similar to the embodiment comprising a coil antenna ( 16 ). First of all, the handle ( 10 ) is pushed with the NFC-compatible card and thus the handle ( 10 ) also pushes backward the handle button ( 21 ) provided therebehind. Upon this pushing action, the processor ( 34 ) detects that there is a contact to the handle button ( 21 ) and the antenna ( 11 ) is activated. The processor ( 34 ) reads the information on the RF tag inside the card by means of the antenna ( 11 ). The user enters the password and rotates the handle ( 10 ) preferably within 5 seconds and switches the same to closed position. Provided that the entered password and the password previously-defined on the RF tag are correct, the micro-motor latch ( 23 ) enters between the rotary shaft notches ( 24 a ) with the motion of the micro-motor ( 25 ) and the electronic lock is locked (provided that the password is wrong, it gives an error alert). In order to re-unlock the electronic lock, first of all, the handle ( 10 ) is again pushed by means of the same NFC-compatible card used during closing of the electronic lock and thus the handle ( 10 ) also pushes backward the handle button ( 21 ) provided therebehind. Upon this pushing action, the processor ( 34 ) detects that there is a contact to the handle button ( 21 ) and the antenna ( 11 ) is activated. The processor ( 34 ) reads the information on the RF tag inside the card by means of the antenna ( 11 ). The user enters the password. Provided that the entered password and the password previously-defined on the RF tag are correct, the micro-motor latch ( 23 ) comes out of the rotary shaft notches ( 24 a ) with the motion of the micro-motor ( 25 ) and the electronic lock is unlocked. The user rotates the handle ( 10 ) in the reverse of the closing direction preferably within 5 seconds and switches the same to open position.
The cabinets ( 37 ) in the areas such as public sports facilities and swimming pools are among the usage areas of the electronic lock. In such places, the same cabinet ( 37 ) is used by many people in different times. In addition to said multiple use, the cabinets ( 37 ) may be in individual use. Only one person knows the lock password in the individual use. If s/he forgets the password, s/he cannot change it and cannot create a new password. It is required to know the last password to be able to change the password.
In the multiple use, on the other hand, “1234” is entered as the password for the electronic lock which is provided on the cabinet ( 37 ) and appears to be open and the electronic lock is switched to closed position by turning the handle ( 10 ). Then, when it is intended to unlock the electronic lock, again “1234” is entered as the password and the electronic lock is switched to open position by turning the handle ( 10 ) in the reverse of the closing direction.
The battery ( 30 ) inside the electronic lock is not active during the sale. Therefore, the processor does not operate, either. As already mentioned, a port (energy harvesting outlet ( 19 a 1 )) which outputs the energy it harvests is provided inside the dynamic NFC tag chip ( 19 a ) and this port is used for feeding the processor ( 34 ). The advantage of the dynamic NFC tag chip ( 19 a ) is to transfer energy to the processor ( 34 ) thanks to the “energy harvesting” outlet thereof. The processor ( 34 ) can process the commands—coming from the mobile device ( 36 ) thanks to the software contained by the mobile device ( 36 )—again by means of the software contained therein even without the battery ( 30 ).
The customers buying the electronic lock may purchase, for example, 500 electronic locks and request 150 of them to have different administrator passwords and 300 to have different administrator passwords. In such case, different passwords can be designated to the electronic locks by means of the mobile device ( 36 ). The electronic lock may not have energy during password designation. The changes are recorded in the processor ( 34 ) by allowing the processor ( 34 ) to operate with the energy supplied through the energy harvesting outlet ( 19 a 1 ) of the dynamic NFC tag chip ( 19 a ).
In an alternative embodiment of the invention, there may not be a keypad ( 18 ) on the electronic lock and the mobile device ( 36 ) can be used instead of the keypad ( 18 ). The password can be entered via the mobile device ( 36 ). When the NFC-compatible mobile device ( 36 ) is drawn closer to the electronic lock, thus to the dynamic NFC tag chip ( 19 a ), the password will be written to the memory of the dynamic NFC tag chip ( 19 a ) and the processor ( 34 ) will read the written password. Provided that the password is correct, the processor ( 34 ) will perform the relevant process; provided it is not, the processor will write to the memory the information suggesting that the password is wrong. And, the mobile device ( 36 ) will read the data in the memory by means of the software contained therein.
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An electronic lock is provided to be used in drawers and cabinet doors made of metal, wood or plastic materials.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our copending U.S. application Ser. No. 709,648, filed July 29, 1976, abandoned.
BACKGROUND OF THE INVENTION
This invention relates generally to liquid dispensing means, and more particularly to such means for dispensing water from five-gallon water bottles.
The practice of selling drinking water in five-gallon bottles is not new, but in more recent years the volume of water thus sold, and the number of companies engaging in the sale of the water, have increased manyfold. From the beginning, the means for dispensing water from such five-gallon bottles has consisted essentially of a stand with a seat to support the shoulder of the bottle in upside-down position, and a gravity-flow faucet arrangement through which the water trickles at a relatively slow rate when the faucet is opened. This rather primitive dispensing apparatus has certain disadvantages, perhaps the chief of which is the necessity of lifting the heavy water bottle to the proper height for use and inverting it into the seat on the stand. A full five-gallon bottle of water weighs about 52 lbs., and this is a heavy weight for anyone to lift. Lifting and maneuvering the heavy bottle of water into its position could cause hernia, or other injury, in even a strong healthy man. For many people, such as most women, disabled persons, older individuals, children, and the like, the task is impossible. Also, there is an inherent risk that a bottle being lifted into position on a conventional dispensing stand will be dropped and break. The breakage of such a bottle causes a minor flood, and creates a mess of rather major proportions that must be cleaned up, as well as setting the stage for personal injury from broken glass and, in some cases, damaging property. Finally, as indicated above, the drawing of water from a water bottle on a conventional dispenser of the above-described type is a fairly slow procedure, and therefore one which is somewhat annoying to many individuals.
U.S. Pat. No. 3,179,292 to Terry discloses a water cooler having a platform adapted to support a pair of five-gallon water bottles and a three-sided cabinet into which the loaded platform can be rolled for use. The water cooler includes a refrigeration unit and an air pump driven by an electric motor to pressurize one of the bottles and thereby force water into the refrigeration unit for cooling. The air pump is of the piston type, and it is common knowledge among those familiar therewith that oil invariably gets past the piston of such a pump to contaminate the air being compressed. The disadvantages of this in a system in which the compressed air contacts drinking water are obvious. Furthermore, the air delivery system in the Terry water cooler has no built-in filtering means to strain particulate matter out of the air passing therethrough. It is well known that indoor air is laden with all types of particulate matter, including dust, soot and the like, and this "dirty" air is pumped directly into a water bottle by the Terry apparatus. Such particulate matter therefore contaminates Terry's drinking water, and, besides being obnoxious by its presence, it carries airborne bacteria into the water to deleteriously affect its potability.
From the foregoing, it will be evident that utilization of the Terry air pressurizing means on bottled water would result in contamination of the water by oil, particulate matter and bacteria and would thus be an unsatisfactory expedient to those bottled water subscribers (no doubt the majority) who use bottled water for its sparkling purity and freedom from unpleasant tasting components of the type found in tap water from the average municipal, or other, source.
SUMMARY OF THE INVENTION
We have now, by this invention, provided a relatively inexpensive liquid dispenser particularly suitable for use in dispensing drinking water from an upright five-gallon water bottle on the floor. When the dispenser is so employed, water is forced out of the bottle by pressurized air, but the air, unlike that of the Terry water cooler discussed above, is free from particulate and bacterial contamination, and free of oil or other foreign matter to pollute the water or give it an unpleasant taste. This air purity is achieved through the use of a field coil actuated pneumatic diaphragm pump with built-in filter means for removing particulate matter from the air being pumped. The pump is in circuit with a microswitch and a control button for turning the pump off and on as necessary to maintain a proper pressure level in the bottle. This pressure level is relatively low, normally within the range from 3 to 5 psig, to avoid any risk of bottle breakage where the bottle is made of glass (the dispenser being equally suitable for use on glass or plastic bottles).
Our novel water dispenser includes, as a critical part, a highly sensitive pressure chamber having a top formed as a distensible diaphragm. The pressure chamber has air line communication with the pump, and is pressurized by the latter simultaneously with pressurization of the water bottle thereby. Water passage means from the bottle to a faucet situated at a convenient height above the floor is provided so that water can be drawn from the bottle through the faucet. The microswitch-pump circuit is normally closed to permit energization (and operation) of the pump. When pressure builds up to the critical level in the water bottle, it also builds up in the pressure chamber and causes the diaphragm to bulge outwardly into contact with the control button of the microswitch, its position relative to the control button being such as to make this possible. The microswitch is highly sensitive, and the slightest movement of the diaphragm against its control button causes the switch to open the circuit and shut off power to the pump. When this occurs, the pressure in the water bottle remains substantially constant because the system is sealed against air leakage. When water is drawn from the bottle through the faucet at the top of the water line, the air pressure within the bottle drops causing the pressure chamber diaphragm to shrink away from the control button of the microswitch. This results in rapid closure of the pump circuit and causes the pump to build up the pressure within the bottle to the critical level again, at which point the diaphragm of the pressure chamber once more opens the microswitch to shut down the pump.
The diaphragm of our novel pressure chamber responds to a very slight pressure drop in the water bottle, for example, such as occasioned by the removal of a glass of water from the bottle (causing a pressure drop of perhaps 1/2 psi or less), and this, coupled with the high sensitivity of the microswitch, results in close control of the pressure level within the water bottle, which, in turn, makes for a fairly constant flow of water from the dispenser, when it is turned on, regardless of the water level in the bottle. The field coil actuated pump is of the type employed for aquarium aerating purposes, and has no moving parts (such as belts, pistons, etc.) or points to wear out. It is therefore capable of long and trouble-free operation with little or no maintenance. Furthermore, its energy requirements are minimal (something like 4 watts, as will be seen), which means that the cost of opertion of the dispenser is extremely low and such operation involves very little drain on the available supply of electrical energy in these days of dwindling energy sources.
The dispenser of this invention has a three-sided, lightweight cabinet mounted on rollers and designed to fit around an upright water bottle on the floor. The design and arrangement of parts of the dispenser are such that it can be easily connected to a standing water bottle on the floor, after which the cabinet can be rolled over the bottle to substantially conceal it from view. No lifting of the heavy bottle of water is thus required so long as the bottle is in the proper place to start with, something that can be easily arranged by proper instructions to a water delivery man.
As will be clear, at least in part, from the foregoing, our novel water dispenser is of relatively simple and inexpensive construction, dependable in operation, long-lasting and relatively maintenance free and of attractive appearance.
It is thus a principal object of this invention to provide relatively inexpensive, dependable, long-lasting, substantially maintenance free and attractive means for use in the dispensing of high purity drinking water from an upright five-gallon water bottle on the floor.
It is another object of the invention to provide such means capable of dispensing the water on demand under optimum flow conditions and at a substantially constant flow rate.
It is still another object of the invention to provide such means which can be used without the necessity of lifting, or otherwise moving, heavy water bottles from upright floor positions.
Other objects, features and advantages of the invention will become apparent in the light of subsequent disclosures herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a water dispensing unit of preferred form in accordance with this invention.
FIG. 2 is an enlarged side view of the unit connected to a five-gallon water bottle for use, the unit being shown partly in section and the near side of a cabinet forming part of the unit being shown partially broken away.
FIG. 3 is a fragmentary view of the water dispensing unit connected to the water bottle, but rolled away from the latter to illustrate the manner in which it can be maneuvered to permit its easy coupling with the water bottle for use.
FIG. 4 is a slightly enlarged cross-sectional view of the unit, taken along line 4--4 of FIG. 2.
FIG. 5 is an enlarged sectional view of a housing supported by a shelf within the aforesaid cabinet, and showing important parts of the unit in top plan view, taken along line 5--5 of FIG. 2.
FIG. 6 is a circuit diagram illustrating the manner in which a microswitch forming part of the unit controls the operation of an air pump forming another part of said unit.
FIG. 7 is an enlarged top plan view of said microswitch and a cooperating pressure chamber forming another part of the unit.
FIG. 8 is a side view of the microswitch and pressure chamber.
FIG. 9 is another view of the microswitch and pressure chamber, this view being similar to FIG. 8, but of partially fragmentary form and showing the pressure chamber in cross-section.
FIG. 10 is a further enlarged side view of the FIG. 8 pressure chamber along with a fragmentary portion of the microswitch to illustrate first contact between a control button on the microswitch and a diaphragm forming the top of the pressure chamber as a result of the outward bulging of the diaphragm under the influence of air pressure in the chamber.
FIG. 11 is a view similar to FIG. 10, but showing the control button pushed slightly inwardly from its normal position by the further distended diaphragm to open the microswitch.
FIG. 12 is a back view of the dispensing unit and water bottle in their FIG. 2 positions, parts of the upper portion of its cabinet being shown partially broken away for better illustrative effect.
FIG. 13 is an enlarged fragmentary sectional view of a rubber closure cap positioned on said bottle and means permitting the passage of air into, and water out of, the bottle, taken along line13--13 of FIG. 12.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Considering now the drawings in greater detail, with emphasis first on FIGS. 1 through 5 and 12, there is shown generally at 10 a water dispensing unit of preferred form in accordance with this invention. Unit 10 includes a backless metal cabinet 16 adapted to fit fairly closely around a five-gallon water bottle 12 in the manner best illustrated in FIG. 4. The cabinet has a pair of vertical side walls 18 and 20, a vertical front wall 22, and a friction fitting top closure 28. Inside cabinet 16 is a wooden shelf 30 stretching horizontally, from side to side, thereacross and supported on a pair of angle iron brackets 11 and 13 spot welded to the side walls of the cabinet, which shelf is secured in position by machine screws 17 (see FIGS. 2 and 12). Preferably, but not necessarily, cabinet 16 is formed from 20 gauge sheet steel.
The shelf 30 supports an air pump and other functioning parts of dispensing unit 10, to be described below, which parts are enclosed by a three-sided wooden housing 14 that rests on the shelf 30, and is prevented from lateral movement by a pair of angled restraints 24 anchored to the shelf by means of threaded fasteners 26 (see FIGS. 5 and 12). Housing 14 abuts against the inner surface of front wall 22 of cabinet 16 so that its three side walls form, with the front wall 22, a surrounding enclosure for the air pump and other functioning parts, referred to above, of the water dispensing unit. The housing 14 has no bottom, because it rests on shelf 30 which forms a floor therefor, but it does have a top closure 15 internally lined with a layer of foam rubber 19. The air pump within the housing 14, shown at 32 in the drawings (FIGS. 2 and 5), is by far the largest of the parts within housing 14 and the top closure of the housing is high enough to clear the top of this pump with sufficient room to admit foam rubber layer 19 as a shock absorbing cushion between the pump and top closure. The pump operates from any 110-volt AC current source, and is provided with a conductor cord 36 fitted with a plug 38 that can be connected to any suitable electrical outlet. The conductor cord 36 passes outwardly through an appropriate opening in the rear wall of housing 14, shown at 84, in the manner indicated in FIGS. 2 and 12. While the conductor cord 36 is shown as an ordinary 2-wire cord, it will be appreciated that a 3-wire cord (with a 3-prong plug) can be substituted therefor if desired, or in jurisdictions where electrical codes require such wiring.
Along their back edges, the side walls 18 and 20 of cabinet 16 are bent to form confronting flanges 40 and 42. The flange 42 has a grommeted opening 44 in an enlarged portion through which the conductor cord 36 passes (see FIG. 12). Near the top of cabinet 16, at the back, is a flat stiffener member 46, preferably, but not necessarily, formed from 16-gauge steel, spot-welded to the inturned flanges 40 and 42, as shown at 48 in FIG. 12. Along the bottom edges of the cabinet side walls 18 and 20, two angle iron stiffeners 50 are spot-welded to those walls in confronting relationship, and at the bottom of front wall 22, a third angle iron stiffener 52 is spot-welded in position (see FIGS. 2, 4 and 12). These three angle iron stiffeners and the cross-piece stiffener 46 near the top of the cabinet serve to prevent twist distortion of the cabinet and give it the strength and durability to withstand accidental kicking of its walls and the various other abuses to which it might be subjected in use. Fastened underneath the inturned flanges of the side walls stiffeners 50 are four rollers 54. These rollers are preferably nylon ball bearing rollers of the type used on patio screen and glass doors, and they permit easy rolling of the cabinet 16 into and out of position around a water bottle for use and bottle changing purposes. Removably supported on a bracket, not shown, on the front wall of cabinet 16, beneath a faucet 56, soon to be described, is a drip basin 58 for said faucet.
The components of water dispensing unit 10 disposed within housing 14 include the aforesaid air pump 32 and a pressure switch assembly 34. Additionally, the unit includes a flexible water line 59, preferably formed of Tygon plastic tubing (which material has been approved bythe Food and Drug Administration as safe for use with drinking water), extending upwardly from a cap 57, to be described in greater detail below, on the bottle 12 to a point near the top of the inner side of front wall 22, where it is connected, through a fitting 55, to the faucet 56 (see FIG. 2). The faucet 56 is a standard-off-the-shelf item of the type having a valve with a push control knob 45 that opens when thumb pressure is applied to the knob. The water line 59 has no sharp turns so that there is minimal resistance to the flow of water therethrough. At its lower end, the water line is clamped onto the upper end of a metal tube 43, preferably of chrome-plated copper with a half-inch bore, that passes through an opening in the cap 57 in the manner illustrated in FIG. 13. Clamped to the lower end of the metal tube 43, beneath cap 57, by means of a clamp 41, is a section of flexible Tygon tubing 39 similar to that from which water line 59 is formed and of suitable length to reach to the bottom of bottle 12 (see FIGS. 2 and 3). Wall 22 of cabinet 16 has a slot 86 in its upper center portion (see FIG. 12) sized to receive the faucet 56 in the illustrated manner. This slot is not a critically necessary feature of the cabinet, however, and its primary purpose is to permit easy removal of the faucet from the unit for unit packaging purposes.
A short air line 37 connects the air pump 32 with a tee 35, a second air line 33 leads from the tee to a metal tube 29 (preferably, but not necessarily, a brass tube of 3/16th-inch bore)penetrating the bottle cap 57, and a third air line 31 extends from the tee to a pressure chamber 62 forming part of the pressure switch assembly 34. The metal tube 29 extends above cap 57 and the lower end of air line 33 is a friction-fitted thereon in the manner illustrated in FIG. 13. The air pump 32 is a low pressure diaphragm pump of the type commonly used in home aquariums for aerating purposes in which the diaphragm movement is actuated by an AC field coil. As previously indicated, such a pump requires very little power for operation, and, we have found, is capable of maintaining a pressure of 3-3.5 psig in the water bottle without any risk of creating dangerous pressure conditions in the bottle, even if let to run continuously. The pump does not run continuously in use, however, but only intermittently, as necessary to maintain a fairly constant pressure in the water bottle.
It is critically necessary, for proper functioning of our water dispensing unit, that the compressed air delivered to a water bottle by pump 32 be substantially free of particulate matter (dust, etc.) and other contaminating material (such as oil and the like).As those skilled in the art will appreciate, our air pump has no parts that function in frictional contact (such as pistons and cylinders), hence is not inherently contaminating by virtue of its manner of operation. Virtually all indoor air, except that in sterile environments, contains quite a bit of particulate matter such as dust and the like, which serves as an excellent carrier for bacteria. To keep such particulate matter and bacteria out of the water dispensed by our unit, we employ suitable filtering means in cooperation with out air pump. Air filtering means are well known, and we do not wish to be limited to any particular type of filter, or filtering system, since any filter, or system, capable of keeping the compressed air from our air pump substantially free of particulate matter will suffice for our purpose. Likewise, we do not wish to be limited to any particular air pump, so long as it is of a type capable of supplying low pressure air to a water bottle for purposes of this invention without contaminating the air with oil or other foreign matter. A pump which we have found to particularly suitable for use in our dispensing unit, however, is an aquarium aerator pump manufactured by Aquarium Air Pump Supply of Prescott, Arizona, sold under the name "Silent Giant, Model 120". This pump has built-in filters of four types (plastic foam, felt, gravel and cotton) that insure the removal of substantially all particulate matter in the incoming air before it reaches the drinking water in a bottle serviced by the unit. We have verified the effectiveness of the filters of the Silent Giant, Model 120 aerator pump in keeping particulate matter, and hence bacteria, out of bottled water pressurized by the pump by having a laboratory test conducted on a sample of water from a bottle that had been nearly exhausted by a water dispenser in accordance with this invention, which dispenser had, as of then, been in continuous use for six months. The test was a standard water potability test conducted by Clinical Laboratory of San Bernardino, Inc., a State-approved water testing facility. The water sample was placed in a sterile bottle in the laboratory, and tested for forty-eight hours for the presence of harmful bacteria. The results showed less than 2.2 coli mpn/100 ml, meaning that the water was potable (free of harmful bacterial contamination). The air pump employed in the dispensing unit used to dispense water from the test bottle was a Silent Giant, Model 120, and the test results showed that, even after six months of service, this pump, with its built-in filters, delivered air substantially free of particulate matter and the bacteria accompanying same to that (test) bottle.
Preferably, the height of faucet 56 above the floor is about three feet (in a prototype, for example, we made the height 37 inches), this being a convenient faucet position for easy use of the dispensing unit by most persons, including children. It is, of course, necessary to maintain enough air pressure in bottle 12 to raise the water to this three-foot height, but excess pressure must be avoided because it would create a danger of bottle breakage in the case of glass bottles (for many years drinking water has been sold in glass bottles, although plastic bottles are now also employed for the purpose). We have discovered that about 3, to 31/2 psig of air pressure provides an excellent flow rate from our unit, and is low enough to pose no threat of bottle breakage. Our discovery of the fact that a pressure this low is suitable for our purpose, and location of an inexpensive, trouble free, long lasting pump to maintain that pressure, were important factors that helped lead us to our unique water dispenser design.
Since it is necessary to operate our water dispensing system under low bottle pressures, a pressure control system of high sensitivity is required. To satisfy this requirement, we have designed a highly sensitive pressure switch assembly (34) capable of controlling operation of the pump so that it ceases to operate when the bottle pressure reaches a desired level (normally 3 to 3.5 psig), and starts up again when the pressure drops below that level. This sensitive pump control assembly is one of the critically important features of our water dispensing unit.
The details of the aforesaid assembly are shown in FIGS. 7-11. Basically, the assembly comprises the abovementioned pressure chamber 62 mounted beneath a microswitch 70 having a control button 72. The pressure chamber is a metallic cup-shaped member 63 having a cylindrical wall, preferably of one-inch diameter, enclosed at the top by a rubber diaphragm 66, preferably of 1/16-inch thickness. The diaphragm is sized to fit congruently on the rim of the cup-shaped member, and is held tightly thereagainst to seal the pressure chamber against leakage by means of a ring retainer 61 press-fitted onto said member. Affixed concentrically to the upper side of the diaphragm 66 is a metallic pressure plate 68. The under side of this plate is partially cemented to the diaphragm with a contact cement of the type used for cementing rubber to metal, but an annular area around the outer portion of the plate is left free of cement to facilitate bulging of the diaphragm under internal pressure in pressure chamber 62 in the manner illustrated in FIGS. 10 and 11. The cylindrical wall of the pressure chamber has a round opening 64 through which it is in communication with the air line 31 from tee 35.
Pressure chamber 62 is positioned under the control button 72 of microswitch 70 so that the button is situated directly over the center of diaphragm 66. The microswitch is of a type that is normally on, and its button is extremely sensitive, being capable of opening the switch when depressed only a slight amount (perhaps no more than 0.002 to 0.005 inch). It is wired in circuit with the AC field coil powering the pump 32, as illustrated in FIGS. 5 and 6, the field coil being schematically shown at 74 on the latter figure.
It is a simple matter to connect water dispensing unit 10 to a bottle of water for use. This can be accomplished by rolling the unit close enough to the bottle to permit cap 57 to easily reach it, then inserting the lower end of the flexible water tube 39 into the open neck of the bottle and threading the tube through the neck until the cap reaches the bottle, then forcing the cap into sealing position thereon. See FIG. 3, which shows typical positions of the bottle and dispensing unit after this has been done. It is now only necessary to roll the dispensing unit cabinet over the bottle to the position illustrated in FIG. 2, and the unit is ready for operation when conductor cord 36 is plugged into a suitable AC outlet.
FIG. 13 illustrates the manner in which cap 57 fits onto the neck of water bottle 12. As there shown, the cap has a cup-shaped hollow with a tapering wall 75 causing the hollow to converge inwardly so that the further the cap is pushed onto a bottle neck, the tighter will be the seal between the cap and neck. This permits use of the cap on the neck of any five-gallon water bottle, glass or plastic, presently employed for the sale of drinking water, at least insofar as we are aware. These bottles vary in neck design, and internal diameters of their neck openings, but all have the same maximum outside diameter so that one cap size will fit any of them. This is true even though the necks of the bottles differ externally in shape, in which connection, some are known to be threaded around counter-recessed portions, some to have the shape illustrated in FIG. 13, etc.
When the flexible water tube 39 is lowered into bottle 12 as far as it ca go, it reaches to a point near the deepest part of the bottle, this being a point near the outer periphery of its bottom, since the bottom has the convex shape (not shown in the drawings) common to five-gallon water bottles. This convex shape works to our advantage, because it permits the flexible tube 39 to reach low enough to remove almost all of the water from the bottle. When the bottle is substantially exhausted of water, dispensing unit 10 can be rolled away from the bottle again to about the distance illustrated in FIG. 3 and disconnected therefrom, then connected to a full bottle in the above-described manner. As will be apparent, once the full water bottle is positioned in a proper place for use by a delivery man, there is no necessity for the consumer to lift or move it in order to dispense its contents with dispensing unit 10.
To insure against the possibility of air pressure within bottle 12 forcing cap 57 off of the bottle, water dispensing unit 10 is provided with flexible retaining means 76 comprising a length of relatively thick spring steel wire, such as piano wire, mounted to swivel at one end in a U-shaped bracket 80 secured to the inner surface of side wall 18 of cabinet 16 by suitable fastening means, all as illustrated in FIGS. 4 and 12. Retaining means 76 is long enough to extend through a locking slot 82 in the side wall 20 of cabinet 16 (see FIG. 1) so that it can be shifted back and forth between a locked position on cap 57, in which its outer end is in a lower arm of the slot 82, as illustrated in FIG. 1, and an unlocked position, in which its outer end is in an upper arm 82a of the slot. At its midportion, wire retaining means 76 is curved to form a loop 78 that fits around the water and air lines passing through the cap into the bottle and rests on the cap when the retaining means is moved to its locked position in slot 82 (see FIG. 4).
When water dispensing unit 10 is connected to a water bottle for use, wire retaining means 76 is adjusted to its locked position, and conductor cord 36 is plugged into a suitable AC outlet, electric current energizes air pump 32 and the pump delivers compressed air to the bottle through air line 37, tee 35, air line 33, and the metal tube 29 through cap 57. At the same time, the compressed air is delivered to pressure chamber 62, from tee 35, through the air line 31. As the air pressure builds up in the system, it causes diaphragm 66 on the pressure chamber to bulge outwardly, in the manner indicated in FIG. 10. The pressure chamber is so designed that as the air pressure in the bottle approaches a desired maximum (for example, about 3.5 psig), the pressure plate 68 on diaphragm 66 touches the control button 72 of microswitch 70. See FIG. 10, which shows the pressure plate as it first touches this control button. Continuing operation of the air pump raises the air pressure enough to cause further upward movement of the pressure plate, which then depresses the control button of microswitch 70 and opens that switch to shut off the power to the pump. Microswitch 70 is, as previously indicated, extremely sensitive, so that the slightest movement of the control button is sufficient to open the switch. FIGS. 10 and 11 graphically illustrated the high sensitivity of the microswitch by showing at 84 the degree of extension of control button 72 at first contact of the pressure plate 68 therewith, and at 86 the extension of the control button after it has been pushed by said pressure plate far enough to open the switch. The difference between extensions 84 and 86, of course, equals the travel distance of the switch button, although the magnitude of this difference is greatly exaggerated in the drawing for better illustrative effect.
When air pump 32 is turned off by the action of diaphragm 66 on microswitch 70, the air pressure in bottle 12 remains substantially constant until someone draws water from the bottle through faucet 56. This air pressure is sufficient to provide a gushing flow of water through the faucet when it is opened by pressure on its push control knob 45, in which connection we have determined that a quart bottle can be filled in about five seconds with our dispensing unit. By way of comparison, we have found that the prior art gravity flow system for obtaining water from a five-gallon bottle typically requires about seventeen seconds to fill a quart-sized container.
If water is drawn from bottle 12, the air pressure inside the bottle drops, and diaphragm 66 flattens to pull the pressure plate 68 down and away from the microswitch button 72. When this occurs, the microswitch closes, to energize the air pump, which resumes operation and again builds up pressure in the bottle to a point at which the diaphragm on pressure chamber 62 bulges to a sufficient extent to open the switch and once more shut down the pump. In this manner a fairly constant air pressure is maintained within bottle 12 as the water is dispensed therefrom, with the air pump coming on, as necessary, to build up the pressure when the withdrawal of water causes it to drop. Virtually all of the water in the bottle can, as previously indicated, be withdrawn by means of our water dispensing unit. To illustrate, we have discovered that all but about three teaspoonsful of the water in the bottle can be recovered by the use of our unit.
Any microswitch capable of performing as taught herein can, of course, be utilized in our water dispensing unit. Such microswitches are available from various sources, but one which we have found particularly suitable is manufactured by MICRO of Freeport, Illinois and commerically available as microswitch Type Z, No. BZ-2RO5.
As will now be apparent to those skilled in the art, the assembly of our water dispensing unit can be accomplished at relatively low cost from simple and inexpensive parts. Furthermove, the resulting unit is a dependable, relatively trouble free system that can be easily repaired when necessary at minimal expense. The unit is capable of dispensing water fast and efficiently with a minimum of waste, and is safe to use because of the low pressure under which it operates. Also, it comes equipped with an attractive cabinet, that can be finished in various ways to suit it for use in any home or office environment. Most importantly, our novel water dispensing unit can function for long periods without contaminating drinking water through the addition of foreign substances from the air or elsewhere, and it can be easily rolled into position over an upright water bottle on the floor for use. There is no necessity of even lifting the bottle a few inches to load the dispenser, as is required in the case of the patented (Terry) water cooler mentioned above. Finally, the air at floor level in a room is substantially cooler (perhaps as much as 5° F. cooler) than the air at the height of bottles in gravity flow dispensers, which means that water dispensed from our unit is cooler, and more refreshing, than that dispensed from a conventional gravity flow unit under most room temperature conditions.
While our novel water dispensing unit has been herein described and illustrated in what we consider to be its preferred embodiment, it will be appreciated by those skilled in the art that our invention in not limited to that particular embodiment,but is broad enough in scope to encompass all modifications thereof incorporative of the structural and functional essence of the invention as taught herein. Certain of these modifications have already been mentioned, and others will occur to those skilled in the art in the light of present teachings. For example, a dispensing unit cabinet of other than metal construction could be substituted for the metal cabinet 16 if desired. Where such a cabinet is employed, it should preferably be made from a material that is substantially noncorrosive in the presence of moisture and otherwise suitable for the purpose, examples of such materials being wood, fiberglass, various plastics other than fiberglass, etc.
Although we have herein stressed the applicability of the novel water dispensing means of this invention for use in drawing water from five-gallon water bottles, it should of course be understood that the unit might well have broader use potential than this, and can be employed in any capacity for which its unique character and capability suit it. For example, it might be employed for the dispensing of liquids other than water and the dispensing of any suitable liquid from other than five-gallon water bottles. Finally, it is emphasized that the scope of the present invention includes all variant forms thereof encompassed by the language of the following claims.
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A unit for dispensing water from a bottle. The parts of the unit include an air pump for pressurizing the bottle, a microswitch having a control button connected in circuit with the pump, a small pressure chamber with a distensible diaphragm for a top, a branched air line connecting the pump with the bottle and the pressure chamber, and a cabinet with rollers that can be rolled to a position of use around the upright bottle. Additionally, the unit includes a water line positioned to extend upwardly away from the bottle. A rubber cap encloses the bottle opening and the water line and a branch of the air line are in communication with the interior of the bottle by means of metal tubes passing through the cap. Fastened to the lower end of the metal tube for the water line is a section of flexible tubing long enough to reach to the bottom of the bottle. The microswitch is normally closed and the pressure chamber is positioned with its diaphragm close to the control button of the switch. When the air pressure in the bottle exceeds a certain limit, the diaphragm bulges outwardly into contact with the button and opens the microswitch. When water is drawn from the bottle through the water line, the air pessure drops, and the diaphragm shrinks away from the control button. This causes the microswitch to close and start the air pump operating to again build up air pressure in the bottle.
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This application claims priority to U.S. Provisional Patent Application 60/713,568 filed Sep. 1, 2005 which is incorporated herein by reference.
FIELD
The present teachings relate to automated methods for calibrating and verifying proper operation of laboratory equipment.
BACKGROUND
Installation and calibration of laboratory instrumentation can be a time consuming and expensive process. In many cases, engineers from the instrument supplier must be on site to perform these processes. This cost is generally passed on to the user. In some cases, experienced users can successfully calibrate properly manufactured instruments using multi-step procedures. During such calibration, physical standards and well plates may be used in combination with manual procedures. Manual calibration processing and data inspection is error prone and may rely on ad hoc or subjective measures. While a final system verification step may provide resilience against accepting suboptimal calibrations, automation offers improved objectivity and uniformity during such activities. The present teachings can incorporate expert knowledge into an automated calibration and verification system providing pass/fail status and troubleshooting feedback when a failure is identified. If an instrument should fail the calibration process, then a service engineer can be called. The present teachings can minimize the cost of, and time required for, the installation and calibration procedures.
BRIEF DESCRIPTION OF FIGURES
FIG. 1 illustrates a computer system on which embodiments of the present teachings can be implemented.
FIG. 2 illustrates a laboratory instrument upon which embodiments of the present teachings can be implemented.
FIG. 3 illustrates a sequence of steps used in the calibration and verification of RT-PCR instruments.
FIG. 4 illustrates a software architecture that can be used in implementing embodiments of the present teachings.
FIG. 5 illustrates the workflows available to a user at the initial outset of the wizard-type application used to implement various embodiments of the present teachings.
FIG. 6 illustrates one possible workflow for setting up a new instrument.
FIG. 7 illustrates one possible workflow providing for instrument calibration.
FIG. 8 shows a screen shot of the main screen of an embodiment of the present teachings. The screen provides several instrument setup and calibration options to the user.
FIG. 9 shows a screen shot of the installation planning screen of an embodiment of the present teachings. Clock icons are used to indicate the amount of time required for each step.
FIG. 10 shows a screen shot of the safety information screen of an embodiment of the present teachings. In addition to providing safety information, this screen can also require that the user has read and understands the information.
FIG. 11 shows a screen shot that informs a user of the steps required to install instrument software.
FIG. 12 shows a screen shot of the calibration screen of an embodiment of the present teachings. The screen provides several calibration options to the user. Depending on the state of previous calibrations or software installations, the wizard can be smart enough to turn certain calibration steps off if they might lead to suboptimal calibration without performing certain other steps first.
FIG. 13 shows a screen shot of a calibration summary screen. In this instance, the instrument failed calibration. The main pane gives the details of failed tests.
FIG. 14 shows a screen shot of a calibration summary screen. In this instance, the instrument passed calibration. The main pane indicates which tests were passed and that the calibration parameters have been saved.
DESCRIPTION
The skilled artisan will understand that the drawings herein are for illustration purposes only. The drawings are not intended to limit the scope of the present teachings in any way. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter herein in any way.
Computer Implementation
FIG. 1 is a block diagram that illustrates a computer system 100 upon which embodiments of the present teachings may be implemented. Computer system 100 includes a bus 102 or other communication mechanism for communicating information, and a processor 104 coupled with bus 102 for processing information. Computer system 100 also includes a memory 106 , which can be a random access memory (RAM) or other dynamic storage device, coupled to bus 102 , and instructions to be executed by processor 104 . Memory 106 also may be used for storing temporary variables or other intermediate information during execution of instructions, corresponding to the methods and present teachings, to be executed by processor 104 . Computer system 100 further includes a read only memory (ROM) 108 or other static storage device coupled to bus 102 for storing static information and instructions for processor 104 . A storage device 110 , such as a magnetic disk or optical disk, is provided and coupled to bus 102 for storing information and instructions.
Computer system 100 may be coupled via bus 102 to a display 112 , such as a cathode ray tube (CRT) or liquid crystal display (LCD), for displaying information to a computer user. An input device 114 , including alphanumeric and other keys, is coupled to bus 102 for communicating information and command selections to processor 104 . Another type of user input device is cursor control 116 , such as a mouse, a trackball or cursor direction keys for communicating direction information and command selections to processor 104 and for controlling cursor movement on display 112 . This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allows the device to specify positions in a plane.
Consistent with certain embodiments of the present teachings, setup and calibration of laboratory instruments can be performed by computer system 100 in response to processor 104 executing one or more sequences of one or more instructions contained in memory 106 . Such instructions may be read into memory 106 from another computer-readable medium, such as storage device 110 . Execution of the sequences of instructions contained in memory 106 causes processor 104 to perform the process states described herein. Alternatively hard-wired circuitry may be used in place of, or in combination with, software instructions to implement the present teachings. Thus implementations of the present teachings are not limited to any specific combination of hardware circuitry and software.
The term “computer-readable medium” as used herein refers to any media that participates in providing instructions to processor 104 for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical or magnetic disks, such as storage device 110 . Volatile media includes dynamic memory, such as memory 106 . Transmission media includes coaxial cables, copper wire, and fiber optics, including the wires that comprise bus 102 . Transmission media can also take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications.
Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, any other optical medium, punch cards, papertape, any other physical medium with patterns of holes, a RAM, PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave, or any other medium from which a computer can read.
Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to processor 104 for execution. For example, the instructions may initially be carried on magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to computer system 100 can receive the data on the telephone line and use an infra-red transmitter to convert the data to an infra-red signal. An infra-red detector coupled to bus 102 can receive the data carried in the infra-red signal and place the data on bus 102 . Bus 102 carries the data to memory 106 , from which processor 104 retrieves and executes the instructions. The instructions received by memory 106 may optionally be stored on storage device 110 either before or after execution by processor 104 .
Implementation of the Present teachings on Real-Time Polymerase Chain Reaction (RT-PCR) Instruments
The present teachings are described with reference to Real-Time Polymerase Chain Reaction (RT-PCR) instruments. In particular, an embodiment of the present teachings is implemented for RT-PCR instruments employing optical imaging of well plates. Such instruments can be capable of simultaneously measuring signals from a plurality of samples or spots for analytical purposes and often require calibration, including but not limited to processes involving: identifying ROI (Regions of Interest), determining background signal, uniformity and pure dye spectral calibration for multicomponent analysis. Calibration may also involve a RT-PCR verification reaction using a known sample plate with an expected outcome. One skilled in the art will appreciate that while the present teachings have been described with examples pertaining to RT-PCR instruments, their principles are widely applicable to other forms of laboratory instrumentation that may require calibration and verification in order to ensure accuracy and/or optimality of results.
The present teachings can be applied to RT-PCT instrument systems. Such RT-PCR instruments are well known to one skilled in the art. For example the present teachings can be applied to instruments such as the Applied Biosystems Sequence Detection Systems 7000/7100/7300/7900, the Roche Applied Science LightCycler® 2.0 PCR amplification system and detection system, the Bio-Rad MyiQ Single-Color Real-Time PCR Detection System, or the Stratagene Mx3000P™ Real-Time PCR System. Such instruments generally use some form of imaging system. While the present teachings are discussed relative to a CCD (charge-coupled detector) imaging system, the present teachings can be easily adapted to any form of imaging system.
In a system with a CCD imaging system, a CCD camera images a sample plate (typically a 96-well plate, although plates with other numbers of wells can be used or sample blocks containing individual tubes can also be used) at various selected dye fluorescent emission wavelengths during a PCR run. In such instruments, the wells are generally illuminated by fluorescence excitation light at wavelengths appropriate to each dye. In order to use the RT-PCR system to accurately monitor PCR amplification using the well emission intensities, the system must be calibrated properly.
FIG. 2 is a schematic illustration of a system used for fluorescent signal detection in accordance with implementations of the present invention. Detection system 200 is an example of a spectral detection system which can be used for RT-PCR data collection and processing in conjunction with aspects of the present invention. As illustrated, detection system 200 includes a light source 202 , a filter turret 204 with multiple filter cubes 206 , a detector 208 , a microwell tray 210 and well optics 212 . A first filter cube 206 A can include an excitation filter 214 A, a beam splitter 216 A and an emission filter 218 A corresponding to one spectral species selected from a set of spectrally distinguishable species to be detected. A second filter cube 206 B can include an excitation filter 214 B, a beam splitter 216 B and an emission filter 218 B corresponding to another spectral species selected from the set of spectrally distinguishable species to be detected.
Light source 202 can be a laser, LED or other type of excitation source capable of emitting a spectrum that interacts with spectral species to be detected by system 200 . In this illustrated example, light source 202 emits a broad spectrum of light filtered by either excitation filter 214 A or excitation filter 214 B that passes through beam splitter 216 A or beam splitter 216 B and onto microwell tray 210 containing one or more spectral species.
Light emitted from light source 202 can be filtered through either excitation filter 214 A, excitation filter 214 B or other filters that correspond closely to the one or more spectral species. The present teachings can be used with a plurality of spectrally distinguishable dyes such as one or more of FAM, SYBR Green, VIC, JOE, TAMRA, NED CY-3, Texas Red, CY-5, ROX (passive reference) or any other fluorochromes that emit a signal capable of being detected. The target spectral species for the selected excitation filter provides the largest signal response while other spectral species with less signal in the band-pass region of the filter contribute less signal response. Because the multiple fluorochromes may have this overlapping excitation and emission spectra, it is useful to apply a pure-dye matrix to correct for the small amount of “cross-talk” (signal from one dye detected with more than one filter set). This process is often referred to as multicomponenting.
Calibration
FIG. 3 shows a sequence of steps that can be used in the calibration and verification of RT-PCR systems and that can be automated by the present teachings.
At 302 , Region of Interest (ROI) Calibration can be performed. Generally ROI calibration can be performed using a plate with strong emissions in each well corresponding to all filters. This can be useful since the ROIs may not be identical for each filter. Differences in the ROIs between filters can be caused by slight angular differences in the filters and other filter spectral characteristics. Thus, various embodiments perform per filter/per well (PFPR)-ROI calibration. These PFPR-ROI calibrations are useful to determine locations of the wells in the 96 well-plate for each filter. ROI calibration can be performed using a method such as the Adaptive Mask Making teachings as described in U.S. Pat. No. 6,518,068 B1. The present teachings can automate the ROI calibration through minimization or elimination of user interaction. Various embodiments can automate the process by providing for software that determine the optimal exposure time per filter using histogram analysis and a binary search pattern. The exposure time is the amount of time required to capture an image of the plate. Again, this value can vary according to a filter's spectral characteristics. Generally ROI calibration will produce information defining the positions of wells in the detector's field of view. This information can be stored as mask files at 304 with either a global mask or multiple masks corresponding to different filters.
An additional calibration step that can be provided for is background calibration ( 306 ). Often, a detector will read some amount of signal even in the absence of a sample emitting detectable signal. Accounting for this background signal can be important as the background signal can be subtracted from a sample signal reading in order to get a more accurate measurement of sample signal. Background calibration can be performed using a water plate to determine the instrument background signal for every filter/well combination. The present teachings can automate this step and minimize or eliminate user interaction. Automation can be provided that will test if the correct plate has been used for background calibration. For example, this stage can look at the signal level and eliminate the possibility of using an incorrect test plate such as the strong signal emitting test plate used in the ROI calibration. If the signal level far exceeds the expected level of the background, the user can be alerted to insert the proper test plate. Also this stage can test for contamination of one or more wells in the test plate by checking for wide divergence of signal levels and if so found, trigger a warning indicating the possible existence of dirty or contaminated wells. Contaminated wells can lead to an improper background signal level being subtracted from the sample signal level. All derived calibration data can be stored in computer files ( 308 ) for later use during sample runs. The present teachings can also guide the user through troubleshooting steps.
Calibration based on uniformity can be performed at 310 . In some cases, variations in plate geometry (warping, thickness) can cause intensity readings to vary across a plate despite the presence of equal amounts of fluorescent dye in each well. Here the present teachings can provide for an automated way that the user can calibrate the instrument using a multi-dye plate so that intensity variations due to plate variations can be corrected for. This calibration can follow the method described in U.S. patent application Ser. No. 10/757903 or U.S. Pat. No. 6,518,068. The present teachings can automate this step and reduce or eliminate user interaction. Parts of this automation can include detection of the use of the wrong calibration plate and detection and adjustments for empty or contaminated wells in the calibration plate.
Calibration to ensure correct multi-componenting can be performed via a Pure Dye calibration step ( 312 ). Here a series of single dye plates can be used to calibrate the system for multi-component decomposition of composite spectra during Real-Time runs. The present teachings can automate this step and minimize or eliminate user interaction. Steps in this calibration can include detection of and adjustment for empty or contaminated wells. Also, a wrong plate test can be run that examines the signal for characteristics of the expected dye spectrum and alerts the user if such characteristics are not found. Also a wrong dye test can be run where, based on known filter assignments to the filter wheel positions, and known spectral characteristics for a filter, it is possible to verify if the dye signal for a named dye is near peak intensity in the assigned filter. Resultant calibration data can be stored in computer files ( 308 ) for later use during sample runs.
Verification of an accurate calibration can be performed by running a known reaction with an expected result ( 314 ). An example of such a test is the Applied Biosystems RNase P Install Plate verification test. The RNase P plate is a sealed plate preloaded with the necessary reagents for the detection and quantification of genomic copies of the human RNase P gene. The RNase P gene is a single-copy gene encoding the RNA moiety of the RNase P enzyme. Each well contains preloaded reaction mix (1× TaqMan® Universal PCR Master Mix, RNase P primers, and FAM™ dye-labeled probe) and template. To verify calibration, this test must demonstrate the ability to distinguish between 5,000 and 10,000 genomic equivalents with a 99.7% confidence level for a subsequent sample run in a single well. Detailed instruction for how such a test can be run can be found in Applied Biosystems Document P/N 4314333. For an instrument such as the ABI PRISM® 7700 SDS, installation specifications are verified if the following equation is satisfied:
[(Copy. Unk. 1)−3( STDev.Unk. 1)]>[(Copy. Unk. 2)+3( STDev.Unk. 2)]
where
Copy.Unk.1=The average copy number of unknown #1 STDev.Unk.1=The standard deviation of unknown #1 Copy.Unk.2=The average copy number of unknown #2 STDev.Unk.2=The standard deviation of unknown #2
The present teachings can be adapted to run a verification test such as the RNase P test and reduce or eliminate user interaction. For example this automation can include steps for automatic detection and removal of standard curve outliers, and automatic detection and removal of unknown replicate outliers with the end result being a pass/fail indication. The present teachings can also automatically compute statistics such as a two-fold discrimination test.
The present teachings can be used to perform “on-the-fly” diagnostics and instrument control combining all manual methods deployed in the existing RT-PCR systems and incorporate expert knowledge to automate and standardize the pass/fail testing at each step. The present teachings can provide certain advantages such as, reducing or eliminating the need for experts during routine calibrations, reducing installation and startup time, reducing or eliminating calibration errors, improving reproducibility of calibration results and decreasing the overall cost of instrumentation by requiring less interaction and servicing by the supplier's engineers.
Many imagers utilizing different technologies can benefit from the present teachings. For example, any other fluorescent or luminescent array imaging systems employing simultaneous detection of arrays that require calibration can benefit from this methodology. Diagnostic devices that require an automated approach to critical steps, such as FDA approved devices, may find advantages in this automation with risk reduction and increased reproducibility. The foregoing list is non-limiting and one skilled in the art will appreciate that the present teachings can be applied in a variety of instruments.
Expert System Algorithms
The present teachings can incorporate expert system capability to automate processes. For the example of applying the present teachings to RT-PCR instruments, the processes of ROI calibration, Background, Optical Uniformity Calibration, Pure Dye Calibration and RNase P install plate verification can all be automated.
ROI Calibration:
The present teachings can optimize the exposure time for each filter using histogram analysis. In this analysis, intensity value histogram results can be used to determine optimal exposure time. Often better results can be attained if the expected range of intensity readings falls within the range of intensities that the detector is capable of reading. If the exposure time is too long, even readings of the background may saturate the detector, if the exposure time is too low, the data may not provided the system with the ability to differentiate between the background and sample signals. Histogram analysis may be used to ensure background readings and strong dye concentration readings are placed near the low end and high end of detector output values respectively. The value chosen between the background and dye peaks that is used to differentiate between them can be referred to as the ROI calibration threshold. Once the exposure times (per filter if required) and threshold(s) are determined, a check on the final image can be performed; the following non-exhaustive list illustrates possible tests to be performed. The instrument passes calibration/verification when no warnings or errors are found and the proper number of wells are located.
Possible warnings include:
Low Exposure: ROI calibration threshold is between (500/4095) and (300/4095) or between 7-12% of full image intensity. This and the following examples assume that the detector passes data to a 12-bit Analog-to-D Converter (ADC) that converts the signal to a value between 0 and 4095. Use of ADCs with other ranges of output values will require appropriate adjustments to the test. The percentages given above and below are suggested values and depending on the specific application, may require adjustment. Poor Focus: The global histogram does not have 30% separation between the ROI calibration threshold and the histogram peak corresponding to the object pixels (peak to the right of the threshold). Light Leak: The peak histogram frequency corresponding to the background pixels (peak to the left of the threshold) is greater than (500/4095) 12% of full image intensity. Over Exposed: The peak histogram frequency corresponding to the object pixels is greater than (3750/4095) or 92% of full scale. Errors (FAILED): The image is too dark as determined by a histogram with a ROI calibration threshold less than (300/4095) or less than 7% of full image intensity. Incorrect Wells: If for any reason the expected number of wells are not found, the calibration fails and the user is notified.
ROI calibration threshold can be based on many standard image processing techniques. One such technique is described in U.S. Pat. No. 6,518,068.
BKGD (Background) Calibration
The previously mentioned background calibration procedure can be automated to include the following tests.
Wrong Plate Test: To test for a wrong plate, readings can be taken for each filter in each well. If there are four filters, then each well will have an associated Four Point Spectrum (FPS.) Using the FPS case as an example, an average of the FPSes can be calculated and the maximum peak of this averaged spectrum can be examined to see if its intensity level exceeds a value that would indicate whether or not a water plate was used as opposed to an incorrect dye plate. For example if the maximum peak in the averaged spectrum is above 100, the user can be informed that the plate likely contains dye or other fluorescent material and that it should be checked, otherwise improper calibration may occur. Contamination Test: A full cross-validation leave-one-out analysis for every well can be used to test for contaminated wells. In this technique an average spectrum of the type discussed above can be calculated with contributions from all wells except the well undergoing examination. From this average value can be subtracted the spectrum from the well under investigation. The elements of this residual can then be tested to ascertain if they are within prescribed limits. Some embodiments require that each element in the residual is within six standard deviations of the corresponding element in the average spectrum. If this is not the case, then the user can be alerted to the possibility of plate contamination. One skilled in the art will appreciate that other threshold values or limits can be set in accordance with typical intra-plate well variations.
UNIF (Uniformity) Calibration
The previously mentioned uniformity calibration can be automated to perform the following tests.
Detection of, and adjustments due to, empty wells: The present teachings can compare the spectrum read when the uniformity plate is in place with the results of the background read. If the signal isn't at least twice the background signal; the well can be designated as empty. Such a test can be used to verify that the plate does contain dyes and is not empty. Wells that are flagged as empty can have their values replaced with the average value of their adjacent neighbors. If the number of wells requiring such treatment exceeds some either user- or supplier-defined threshold, then the user can be alerted to the situation and informed of troubleshooting steps. Detection of, and adjustments due to, contaminated or corrupt wells: Various embodiments may determine wells are contaminated or corrupt by applying a full cross-validation, leave-one-out test analysis similar to the one described in the section on background calibration. Again, testing each element of the residual against acceptable limits can be used. Suitable limits of variation may be set as the mean value for the corresponding element in the across the plate average plus or minus six standard deviations. Well repair: Wells that are flagged as either empty or contaminated can have their values replaced with the average value of their adjacent neighbors. If the number of wells requiring such treatment exceeds some either user- or supplier-defined threshold, then the user can be alerted and told the necessary troubleshooting steps. Wrong Plate Test: A wrong plate can be tested for by examining the plate's average well spectrum. If this average spectrum is not flat, then the user can be alerted to the possibility of having used an incorrect plate. A non flat spectrum may be indicative of the plate not containing the dyes required for calibration. One method of determining whether or not the spectrum is flat is to compute a ratio between the maximum value in the average and the minimum value in the average. If the ratio is greater than some specified value (such as 10), the spectrum is likely not flat and calibration can be stopped and the user notified. The following values (taken on an Applied Biosystems SDS 7500 system) indicate ratios for wells containing pure dyes calculated in the above manner. TEXAS RED peak ratio=2519.5 JOE peak ratio=68618.7 FAM peak ratio=53053.0 VIC peak ratio 24105.8 TAMRA peak ratio=9555.1 SYBR peak ratio=76058.8 NED peak ratio=48610.4 CY3 peak ratio=51392.1 CY5 peak ratio=21426.6 ROX peak ratio=1586.7 UNIFORMITY plate #1 peak ratio=2.89033 UNIFORMITY plate #2 peak ratio=2.08429
Here it can be seen that using the proper uniformity plate, which contains the requisite balance of dyes, results in peak ratios much lower than if pure dyes alone were in the plate.
PDYE (Pure Dye) Calibration:
When performing the pure dye calibration the same detection and repair of empty wells and detection and repair of contaminated or corrupt wells steps as used in the uniformity calibration can be implemented. The following tests can also be implemented.
Wrong Plate Test: In a similar manner as presented previously, a plate average spectrum (PAS) can be calculated. The PAS can be tested for flatness and if the PAS is essentially flat, it is unlikely that the correct plate was used. One method that can be used to determine if the spectrum is flat is to use a ratio between the maximum value of the PAS and the PAS's minimum value. If the ratio is less than some pre-defined value (for example 10), the spectrum likely does not have a characteristic dye shape and the user should be alerted of an error condition and the dye can be prevented from being calibrated. Wrong Dye Test: If a value in the PAS corresponding to the expected peak for a given dye has a low value, then it is possible that, the wrong dye plate is being used. One test to determine if the spectrum has sufficient signal can be based on normalizing the PAS so that the maximum peak has a value of one and then testing to ensure that the peak in the PAS corresponding to a particular value has a normalized intensity of at least 0.75. If not, then it is likely that the wrong dye plate is present and the user can be informed of a possible error condition and calibration halted until the problem is rectified.
RNaseP Install Plate Verification:
The aforementioned RNase P plate verification procedure can be automated and various tests implemented. The results of the tests can be used to trigger warnings to the user and provide them with troubleshooting information. For example, the following steps can be implemented.
If the standard curve correlation coefficient<0.990, then standards in each replicate set can be removed using a Grubbs outlier test (also known as the Extreme Studentized Deviant test) to detect outliers. If the standard curve correlation coefficient is less that 0.990 after outlier removal, the instrument can fail verification. If the two-fold test fails, then unknowns can be removed in each replicate set using a Grubbs test to detect outliers. If the two-fold test fails after removing unknown outliers, then the install plate verification can be flagged as failed. Maximum of 1 outlier removed per standard group Maximum of 6 outliers allowed per unknown group Apply the two-fold test which requires that two populations have distinguished means at the 95% confidence level. For example assuming populations at 5,000 and 10,000 copies a formula such at the following may be used:
PASS=(10K mean−3*10K sigma)>(5K mean+3*5K sigma) 5K=mean of quantity of 5K unknown population (with possible outliers removed) 10K=mean of quantity of 10K unknown population (with possible outliers removed) Sigma=standard deviation of population
If both the standard curve correlation coefficient greater than or equal to 0.990 and the two-fold test is passed.
Software Architecture
An embodiment of the present teachings can be constructed so that it consists of two major applications. The main application—“System Diagnostic Software Application” (SDSA) ( 450 ) controls the instrument ( 470 ) and performs the actual calibration and analysis. The other application “Real-Time System Setup Wizard” ( 410 ) uses SDSA to automate the installation and calibration of RT—PCR systems. The overall system is represented in FIG. 4 .
In order to communicate with other applications SDSA can be developed as a DCOM ActiveX Automation Server. DCOM is the Distributed Component Object Model standard defined by Microsoft. COM allows for a set of interface functions to be defined through the IDispatch interface calling mechanism as defined by Microsoft for Automation servers. The SDSA Server is dedicated to the control of an instrument, and as such will allow only one client connection at a time.
In addition to the main SDSA application installed on the PC, a Client-Side ActiveX Control (.OCX) ( 420 ) can be made available in order to ease third party development of client applications. The SDSA server ActiveX control can manage the aspects of the Server Connection and Callback mechanism without additional development Client-side knowledge.
Workflow Overview
The present teachings provide for a “wizard” type application which can help the user to accomplish tasks by providing step by step instructions taking the user through a series of screens. Screens can be configured so that they will let the user proceed to the next screen when appropriate, return to the previous screen or cancel out of the current task completely and return to the main screen. Steps can contain instructions and information taken directly from the instrument installation and operation manuals as well as identifying troubleshooting steps should any of the tests fail. In general, the wizard lays out a workflow for the user to follow in order to calibrate an instrument and/or verify that it is working correctly. The wizard can also contain expert knowledge that can internally verify that the user is following the procedure correctly and is inserting the proper test plates into the instrument, that the test plates themselves are without problems and that the instrument is processing data correctly. The following describes an embodiment of the present teachings but one skilled in the art will appreciate that steps can be added or removed in order to adapt to different instruments.
The main application screen provides three options that the user can choose from. The option availability can reflect the current state of the system. Not all options may be available for all systems at all times. The wizard can be “smart” enough to not provide the calibration option if the software required to run the instrument is not installed. The workflow for the main screen is illustrated in FIG. 5 . The screen itself is illustrated in FIG. 8 . If the user decides at 508 to unpack, install and configure a new instrument, execution follows branch 510 . In this branch a more detailed workflow occurs that is laid out in a separate figure. This additional workflow takes the user through the entire process of setting up a brand new system from unpacking to calibration. This option can automatically perform all necessary calibrations. At the end of this process the system can be completely ready to perform analysis. This process assumes that the operating system is already installed. If the user decides only to install or upgrade the instrument software (herein referred to as “SDS” software) program, execution will continue along branch 520 . This additional workflow can limit user interaction to installing the instrument software only and may be configured as so to not take the user through the calibration process. If the user chooses to calibrate the instrument, program execution will continue along the branch at 530 . This workflow assists the user in calibrating the system. It may assume or check that the instrument system has the SDS software installed. The user can have some choice in what calibrations and in what order to perform them ( 540 ) but the wizard can insure that the order is correct. The user can select from the calibrations previously mentioned or, depending on the needs of the instrument, other calibration steps may be required. This wizard can guide the user through the calibration process by providing step by step instructions and clearly indicating calibration results.
Unpacking and Setting Up a New Instrument
if the user chooses the execution branch 510 in FIG. 5 , the “Unpack and Set Up a New Instrument” option, a workflow comprising steps required to set up the instrument will be started in order to take the user through the process of setting up a new instrument. The following steps illustrate an embodiment of the present teachings that facilitates instrument setup. At 605 the user can be provided with an overview of the entire setup process which can include the time required and workflow aspects. An embodiment of such a screen is illustrated in FIG. 9 which shoes the individual steps and represents the approximate time required for each step with a clock icon. This information can prompt the user to set aside adequate time to ensure that the installation is performed correctly. Next at 610 , the user can be provided with safety information. An embodiment of such a screen is represented in FIG. 10 which shows the window itself ( 1000 ) and other visual information such as the present location in the installation process ( 1020 ) and the safety information ( 1030 ). This screen can be configured such that the user will not be allowed to proceed until they confirm that the information was reviewed. Confirmation can be acknowledged at 612 by checking a checkbox (see FIG. 10 's 1010 ) to indicate that the user has read and understood the safety information. Further information regarding installation may be passed to the user at 615 . At 620 , the user can be provided with information about additional hardware and software the user may need, or has an option of getting for the system being installed. A confirmation that the user has all the required materials may be required at 617 prior to allowing the user to continue. The user can be instructed on how to unpack the instrument without damaging it at 625 and when completed, can be asked to verify that all materials were received at 630 and 632 . Information contained at workflow step 635 can provide instructions on how to get the instrument to the power up state. This can include can include checking the instrument for damage, securing access panels/doors and other parts, connecting the power cord and any other required steps. The workflow can then prompt for the media containing the SDS software Documentation at 640 and 642 . At 645 , the user can be prompted to install the SDS software. This step can install the main SDS software application. The screen can detail the installation process (see FIG. 11 a ) but the process itself can be guided by a separate installer as is indicated in the information in the main panel of the screen shot in FIG. 11 a . The user may need to follow on-screen instructions of that installer to complete the installation process. The user can be allowed to proceed only when the software installation is complete by acknowledgment (see checkbox on FIG. 11 b .)
With the instrument fully unpacked and the SDS software installed on the instrument computer, the workflow can next prompt the user to power the instrument up at 650 . This step can instruct the user to connect the instrument to the computer and to power on the instrument. The user can be required to confirm the power on state at 652 . Function testing can occur at step 660 in the workflow. This step can test all major instrument hardware components and verify the firmware version. If the instrument doesn't have the latest firmware, the user may be given an option to download it. The progress of the function test can be viewed in the status window and by tracking the progress bar. Upon completion of the test, the status window can contain detailed information on the test results and the progress bar can read “Passed” or “Failed”. If the test fails, the user can rerun the test or return to the main screen. If the test succeeds, the user may be allowed to proceed to the system calibration step.
If the user selects the “Install/Upgrade SDS Software” option ( 520 ) on the main screen ( 505 ), the workflow can take the user through the process of installing or upgrading the main SDS application much as it did in steps 640 through 660 .
Calibrating the Instrument
Selecting the “Calibrate the Instrument” option on the main screen can take the user to a screen containing various calibration options where appropriate options for the installed system can be enabled. This is illustrated in FIG. 12 which shows choices for complete calibration ( 1205 ), ROI calibration ( 1210 ), background calibration ( 1220 ), Optical calibration ( 1230 ), pure dye calibration ( 1240 ) and instrument verification ( 1250 ). The user may choose to perform any number of calibrations at a time, but the software can validate the selection based on the state of the system. If a successful ROI calibration was never performed, the user may not be allowed to perform the background calibration or any other calibration listed after the ROI calibration on the option screen. The following series of steps, with reference to FIG. 7 , is employed in various embodiments of the present teachings.
At 705 the user can be given a calibration overview which may include information such as the time required, the purpose and importance of calibration, when and if the instrument has been previously calibrated, and calibration guidelines. Step 710 can present the user with a list of materials and consumables required for the calibration. The workflow may require confirmation at 712 that all necessary materials have been procured by the user. Step 715 can require that user prepares any required calibration plate. Typically this involves removing the calibration plate from the freezer, allowing it to warm to room temperature and centrifuging it. The user may not be allowed to proceed until they confirm that the plate is ready by checking a plate ready checkbox at step 718 . Once a calibration plate is ready, the workflow can instruct the user to place the plate in the instrument at 720 . Again confirmation may be required at step 722 . Actual calibration of the type selected can be performed at 730 . The calibration progress can be displayed in a status window and can be tracked visually by a moving progress bar. After the calibration is complete the progress bar can display Passed or Failed. If the calibration passes the user may be able to proceed to the next calibration if any. If the calibration fails, the status window can contain the detailed explanation of the failure. Various embodiments will report to the using a summary of the calibration and verification test. Such a report illustrating calibration failure is illustrated in FIG. 13 . Similarly, a calibration summary showing passing results and that the parameters required for subsequent sample runs have been saved is illustrated in FIG. 14 . When calibration is complete, the user may have an option of switching to the main SDS application to examine the failed run and/or perform the calibration again using the same plate. Plate unloading instructions and confirmation can then occur at 750 and 755 . All calibration information can be saved to calibration files either inside the instrument itself, on a computer attached to the instrument, or via some other storage media.
In various embodiments, the workflow can recognize that an instrument may need to be calibrated for several dyes and the dye calibration work flow steps contained in FIG. 7 can be iterated through all system specific dye calibrations one by one. This can dramatically simplify the process of dye calibration for the user. The above workflow can also be used for different calibration phases such as the ROI calibration. However each type of calibration may have specific requirements that need to be taken into account. For example, in the ROI calibration case where an instrument has multiple filters, the following ROI calibration specific details may have to be taken into consideration. When the user gets to the calibration screen, the application can determine the number of available filters and can calibrate all of them one by one. The calibrations can be saved only if all filters calibrate successfully. If at least one of the filters fails, none of the filters can be considered calibrated (or subsequently saved) during that round of calibration. The information can be shown on a per filter basis in the status window.
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities of ingredients, percentages or proportions of materials, reaction conditions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a range of “1 to 10” includes any and all subranges between (and including) the minimum value of 1 and the maximum value of 10, that is, any and all subranges having a minimum value of equal to or greater than 1 and a maximum value of equal to or less than 10, e.g., 5.5 to 10.
It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural referents unless expressly and unequivocally limited to one referent. Thus, for example, reference to “a monomer” includes two or more monomers,
It will be apparent to those skilled in the art that various modifications and variations can be made to various embodiments described herein without departing from the spirit or scope of the present teachings. Thus, it is intended that the various embodiments described herein cover other modifications and variations within the scope of the appended claims and their equivalents.
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Method and system providing an automated workflow for installing and/or calibrating laboratory equipment. The workflow empowers an end user to perform installation and calibration thereby reducing the costs associated with such activities. The automated workflow taught herein, can greatly reduce the incidence of calibration error by providing for verification of certain events during the calibration process.
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a Continuation In Part of U.S. patent application Ser. No. 10/251,249, filed on Sep. 20, 2002. U.S. patent application Ser. No. 10/251,249 is hereby incorporated by reference.
TECHNICAL FIELD
This invention relates to telecommunication switching systems, and in particular, to the provision of status information.
BACKGROUND OF THE INVENTION
Within the prior art, it is well known to convert visual terminal status information to audio information so that visually impaired people can receive the status information. Terminal status information includes, but is not limited to, caller identification (name and number), call operations, telephony terminal states, and notification that a new voicemail message has arrived. The prior art has provided the audio information for terminal status information by utilizing special hardware to perform voice synthesis. This hardware was designed specifically for visually impaired users, and consequently, was expensive. In addition, the special hardware was connected between the telephone set of the user and the telecommunication system.
SUMMARY OF THE INVENTION
A method and apparatus provide terminal status information by a telecommunication terminal as audio information by generating terminal status information by a telecommunication terminal; establishing a direct connection by a monitor computer to the telecommunication terminal via a direct link to the telecommunication terminal; transmitting the generated terminal status information to the monitor computer by the telecommunication terminal via the direct link; converting the generated terminal status information to audio terminal status information by the monitor computer; and presenting the audio terminal status information to a user of the telecommunication terminal. In addition, the method and apparatus establish a firewall by the telecommunication terminal to prevent the monitor computer from communicating on a network to which the telecommunication terminal is connected whereby the monitor computer is also denied access to other devices connected to the network.
Further, the method and apparatus provide terminal status information intended for visual presentation as audio information by establishing a direct connection by a monitor computer to a telecommunication terminal via a direct link to the telecommunication terminal; receiving terminal status information intended for visual presentation by the telecommunication terminal via a network from an endpoint; transmitting terminal status information intended for visual presentation to the monitor computer by the telecommunication terminal via the direct link; converting the terminal status information intended for visual presentation to audio terminal status information by the monitor computer; and presenting the audio terminal status information to a user of the telecommunication terminal.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates, in block diagram form, an embodiment;
FIG. 2 illustrates, in block diagram form, an embodiment;
FIG. 3 illustrates, in pictorial form, an embodiment of an IP telephone set;
FIG. 4 illustrates, in block diagram form, an embodiment of an IP telephone set;
FIG. 5 illustrates, in flow chart form, operations performed by an embodiment of a status control routine;
FIG. 6 illustrates, in flow chart form, operations performed by an embodiment of an audio control routine;
FIGS. 7-9 illustrate, in flow chart form, operations performed by an embodiment of a monitor computer;
FIG. 10 illustrates, in block diagram form, an embodiment of a monitor computer;
FIG. 11 illustrates, in block diagram form, an embodiment; and
FIG. 12 illustrates, in block diagram form, an embodiment of an IP communication terminal.
DETAILED DESCRIPTION
FIGS. 1 , 2 , and 11 illustrate embodiments for implementing the invention. In FIG. 1 , control computer 101 performs the overall control functions for conventional telephones 107 - 108 and IP telephone sets 112 - 113 . IP telephone sets 112 - 113 may be IP telephone set 4624 manufactured by Avaya Inc. or a similar telephone set. Switching network 105 performs the switching of not only audio information but also control information to and from computer 101 to the telephone sets. Computer 101 is interconnected to wide area network (WAN) 111 via network trunk 106 . Control computer 101 controls the activity of IP telephone sets 112 - 113 by the transmission of terminal status information and the receipt of terminal status information from the IP telephone sets via WAN 111 . Control computer 101 controls telephones 107 - 108 by the transmission of status and reception of control information via switching network 105 . Telephone sets 107 - 108 can be analog telephone sets, ISDN telephone sets, or proprietary digital protocol telephones sets. Monitor computer 118 is utilized to provide the audio information representing the visual status signals of one of the IP telephone sets. Monitor computer 118 can be a desktop PC, laptop, a pocket PC, or a hand held unit. Telecommunication switching system 100 is connected to public switching network 116 via CO trunks 109 and trunks 114 .
FIG. 2 illustrates another embodiment for implementing the invention. Control computer 202 is controlling the operations of IP telephone sets 207 - 208 with respect to telecommunication operations by the transmission and reception of control information via WAN 204 . Service circuits 206 under the control of control computer 202 provide tone generation, conferencing, etc. via WAN 204 to IP telephone sets 207 - 208 . For a telecommunication call which is only between two IP telephone sets, the IP telephone sets communicate via WAN 204 for the transmission of audio information. Public switching network 201 is interconnected to WAN 204 via IP trunk 203 . Monitor computer 209 and server 219 perform similar functions to those performed by monitor computer 118 and server 119 of FIG. 1 .
Consider now an example of how monitor computer 118 would provide audio terminal status information for IP telephone set 112 in one embodiment of the invention. To perform its operations, monitor computer 118 establishes communication with IP telephone set 112 via link 121 . Link 121 can be a USB link, infrared link, wireless link, Bluetooth link, wired link, or any other type of link well known to those skilled in the art.
Control terminal status information transmitted from computer 101 to IP telephone set 112 is relayed to monitor computer 118 by IP telephone set 112 . In one embodiment of the invention, monitor computer 118 is responsive to the terminal status information being received from IP telephone set 112 which will cause different indicators to be lit on IP telephone set 112 to convert this terminal status information into audio information that monitor computer 118 presents to the user via a speaker, headphones, or other types of audio transducers attached to monitor computer 118 . As will be discussed later, the user of monitor computer 118 has the capability for determining what type of terminal status information will be presented in audio information and also how often.
In the previous example, the embodiment utilized the audio reproduction capability of monitor computer 118 to present the audio terminal status information to the user. In another embodiment, monitor computer 118 transmits the audio terminal status information to IP telephone set 112 via link 121 for presentation to the user. Monitor computer 118 is responsive to the terminal status information being transmitted to IP telephone set 112 , to convert the terminal status information to audio terminal status information, and to transmit this audio terminal status information via link 121 to IP telephone set 112 . In response to the audio terminal status information from monitor computer 118 , IP telephone set 112 presents this information to the user via the internal CODEC of IP telephone set 112 . The output of the CODEC of IP telephone set 112 presents the audio terminal status information to the user in the same audio stream as is being utilized for the actual telecommunication call. Alternatively, IP telephone set 112 could utilize a built-in speaker such as one used as a speaker phone to present this information. Alternately, as is well known to those skilled in the art, IP telephone set 112 could also convert the received audio terminal status information to information to be presented to the user using another conversion technique rather than that used by its CODEC.
The previous embodiments described for FIG. 1 can be implemented on the system illustrated in FIG. 2 .
In an embodiment of an IP telephone set in order to protect the systems of FIGS. 1 and 2 from a security breach via the IP telephone set by a monitor computer, the IP telephone set has a firewall not to prevent access to the IP telephone set from the systems of FIGS. 1 and 2 ; but rather, to protect the systems from access by the monitor computer. The access to the monitor computer is restricted only to the IP telephone set, and the monitor computer can not access the systems via the IP telephone set when the firewall is used. Note, an IP telecommunication terminal of FIG. 11 could also employ a firewall.
FIG. 3 illustrates an embodiment of IP telephone set 112 . The user of IP telephone set 112 speaks and listens through handset 302 . Although not illustrated in FIG. 3 , IP telephone set 112 also has a speaker and microphone for conference calls. Display 301 is utilized to display the telephone number being dialed by keypad 309 during the placement of an outgoing call and displays the name and telephone number of the calling party for an incoming call. IP telephone set 112 has a number of telephone lines that could be selected with each line being denoted by a pair of indicators and a button. For example, indicators 303 and 304 and button 307 indicate line 1 . Indicators 305 and 306 and button 308 indicate line 2 . If the user is active on line 1 , indicator 304 will be on as well as indicator 303 . If the user has a caller on hold on line 2 , indicator 305 will flash. The user of IP telephone set 112 selects line 1 by activating button 307 . Similarly, the user activates line 2 by activating button 308 .
Pairs of indicators and buttons, such as indicator 309 and button 311 , may be used for activating a variety of operations. One is to automatically dial a party that had been preprogrammed by the user or to activate a feature such as using the conference facilities of IP telephone set 112 . If button 311 is activated, indicator 309 will turn on. Indicator 312 and button 314 have similar functions. In general, there would be a number of such combinations of indicators and buttons as illustrated by 309 , 311 , 312 , and 314 . All button activation information is transmitted to control computer 101 , and control computer 101 controls the state of the indicators. Conductor 316 provides the communication for link 121 or 221 . This conductor 316 may be a mechanical connector if link 121 or 221 is a USB link or a infrared or wireless port for a infrared or wireless link. One skilled in the art could readily envision conductor 316 being located on a different surface of IP telephone set 112 .
FIG. 4 illustrates, in block diagram form, one embodiment of IP telephone set 112 . Processor 402 provides the overall control for the functions of IP telephone set 112 by executing programs and storing and retrieving data from memory 401 . A processor such as processor 402 may also be referred to as a central processing unit or a computer. Processor 402 connects to WAN 111 or 204 via interface 403 . Processor 402 interfaces to handset 423 via interface 407 , to speaker phone 406 via interface 404 and connects to visual display and buttons 419 via interface 409 . Visual display and buttons 419 is all of the indicators, buttons keypad, and display of IP telephone set 112 . Interface 421 provides an interface to monitor computer 118 . Processor 402 performs the operations of IP telephone set 112 by executing the routines illustrated in memory 401 .
Operating system 412 provides the overall control and the necessary protocol operations. Operating system routine 412 provides all control functions required to implement the TCP/IP protocol as is well known to those skilled in the art. CODEC 414 encodes and decodes the audio information for communication with handset 423 or conference speaker and microphone 406 for communication with WAN 111 or 204 . Overall control of the call processing is performed by the IP telephone set 112 under the control of call processing routine 416 . The communication and control of the various interfaces illustrated in FIG. 4 is provided by interfaces routine 417 . Audio generator routine 414 implements other software methods for reproducing sounds for utilization with the invention.
Terminal status control routine 408 terminates the communication that is established by monitor computer 118 via interface 421 to receive the terminal status information from IP telephone set 112 as described in the previous examples. Terminal status control routine 408 is responsive to messages from monitor computer 118 to establish the communication that allows monitor computer 118 to communicate with terminal status control routine 408 . When monitor computer 118 initiates communication with IP telephone set 112 , it establishes communication with interface 421 and terminal status control routine 408 of IP telephone set 112 . Terminal status control routine 408 receives information from call processing routine 416 concerning control information received via WAN 111 to update indicators or display 301 of visual display and buttons 419 . Similarly, terminal status control 408 receives actuation information for buttons or the keypad of block 419 from call processing routine 416 . Terminal status control 408 transmits this terminal status information to monitor computer 118 .
Audio control routine 411 also establishes communication with monitor computer 118 in a manner similar to terminal status control routine 408 , as described in the previous examples, to have IP telephone set 112 reproduce the audio terminal status information. In this manner, monitor computer 118 and audio control routine 411 are interconnected. The operating system of the IP telephone set 112 then directs future audio messages from monitor computer 118 to audio control routine 411 . Similarly, messages from audio control routine 411 to link 121 are transmitted to monitor computer 118 . The speaker of unit 406 or the receiver of handset 302 can be utilized for this reproduction of the audio terminal status information. Audio control 411 can utilize CODEC routine 414 to reproduce this audio terminal status information or audio generator routine 418 . The audio information is transferred via the appropriate handset to either the speaker or receiver.
Firewall routine 422 controls all access to the WAN via interface 403 . Firewall routine 422 will allow software elements such as operating system 412 or call processing routine 416 access to the WAN but will not allow status control routine 408 to communicate via the WAN. Firewall routine 422 prevents status control routine 408 or audio control routine 411 from communicating via the WAN so as to prevent the monitor computer from getting unauthorized access to the WAN. This is done to protect the data security of the systems illustrated in FIGS. 1 , 2 , and 11 . Note, firewall routine 422 will prevent any routine having direct communication with the monitor computer from communicating with the WAN. Firewall routine 422 operates in a manner well known to those skilled in the art.
FIG. 5 illustrates, in flowchart form, operations performed by an embodiment of a status control routine such as status control routine 408 of FIG. 4 . After being started in block 500 , decision block 501 determines if the routine is active with respect to receiving terminal status information from an IP telephone set. Active in this case means that there is communication set up between the monitor computer and an IP telephone set by the operating system. If the answer is no, decision block 502 determines a device has been connected to has been connected to connector 316 . This may indicate that a monitor computer is attempting to establish communication with a status control routine. If the answer is yes, decision block 503 determines if the correct device has been connected. If the answer is no, control is transferred back to decision block 501 . If the answer is yes, block 504 makes the state active and sends a message to the operating system to establish the communication with the monitor computer. Note, that one skilled in the art could readily envision that blocks 501 - 504 could be performed within the operating system or some other routine.
If the answer is yes in decision block 501 or no in decision block 502 , control is transferred to decision block 506 . Decision block 506 determines if there is new terminal status information from the call processing routine. For certain types of links, the monitor computer may have to periodically poll the IP telephone set. If the answer is no, control is transferred to decision block 507 which determines if communication has been lost with the monitor computer. The operating system would normally detect this loss of communication and inform the status control routine in a manner well known to those skilled in the art. If the answer is no in decision block 507 , control is transferred to block 509 which performs normal processing before returning control back to decision block 501 . If the answer in decision block 507 is yes, control is transferred to block 508 which sets the state to non-active before returning control back to decision block 501 .
Returning to decision block 506 , if a terminal status message has been received from the call processing routine, block 511 transmits this message to the monitor computer before transferring control back to decision block 501 .
FIG. 6 illustrates, in flowchart form, operations performed by one embodiment of an audio control routine such as audio control routine 411 of FIG. 4 . After being started in block 600 , decision block 601 determines if the routine is active with respect to receiving terminal status information from an IP telephone set. Active in this case means that there is communication set up to a monitor computer by the operating system. If the answer is no, decision block 602 determines if a connection has been made to connector 316 . This may indicate that a monitor computer is attempting to establish communication with a status control routine. If the answer is yes, decision block 603 determines if the correct device has made the connection. If the answer is no, control is transferred back to decision block 601 . If the answer is yes, block 604 makes the state active and sends a message to the operating system to establish communication between the monitor computer and the IP telephone set. Note, that one skilled in the art could readily envision that blocks 601 - 604 could be performed within the operating system or some other routine.
If the answer is yes in decision block 601 or no in decision block 602 , control is transferred to decision block 606 . The latter decision block determines if a voice message has been received from the monitor computer. If the answer is no, control is transferred to block 614 whose operations are described below. If the answer in decision block 606 is yes, decision block 608 determines if the voice message designates that the CODEC routine of the IP telephone should be utilized to present the message to the user. If the answer is yes in decision block 608 , the message is sent to the CODEC routine by block 609 . Note, if the message is sent to the CODEC then the message will be played in the receiver of the IP telephone set that is currently being utilized by the user.
Returning to decision block 608 . If the answer is no, decision block 612 determines if the message designates that the audio generator routine is to be used to present the message to the user. If the answer is yes, block 613 transmits the voice message to the audio generator routine before transferring control back to decision block 601 .
Returning to decision block 612 , if the answer is no, control is transferred to decision block 614 which determines if communication has been lost with the monitor computer. The operating system would normally detect this loss of communication and inform the status control routine in a manner well known to those skilled in the art. If the answer is no in decision block 614 , control is transferred to block 617 which performs normal processing before returning control back to decision block 601 . If the answer in decision block 614 is yes, control is transferred to block 616 which sets the state to non-active before returning control back to decision block 601 .
FIGS. 7-9 illustrate, in flowchart form, operations performed by one embodiment of a monitor computer such as monitor computer 118 of FIG. 1 where the monitor computer is receiving the terminal status information from an IP telephone set. After being started, in block 700 , block 701 obtains the control routine whose operations are illustrated in FIGS. 7-9 . The control routine will be obtained from internal memory. After the control routine is obtained and executed, decision block 702 determines if it is necessary to tailor the user interface or the user. This decision is based on whether the system allows such tailoring and whether it is necessary. It may be that the interface has already been tailored for the user, and this information is stored in an interface database. If the answer in decision block 702 is yes, control is transferred to block 902 of FIG. 9 . If the answer in decision block 702 is no, block 703 waits for a connection to be made to an IP telephone set.
After execution of block 703 , control is transferred to decision block 706 which determines if an IP telephone set is connected. If the answer in decision block 706 is no, control is transferred to block 707 which performs error recovery before transferring control back to block 703 . If the answer is decision block 706 is yes, block 708 establishes communication with the operating system of the IP telephone set that is connected. Block 708 establishes communication to the status control routine of that IP telephone set before transferring control to decision block 801 of FIG. 8 .
Decision block 801 determines if terminal status information has been received as a message from the IP telephone set. For certain types of links, decision block 801 may have to periodically poll the IP telephone set. If the answer is no, decision block 802 determines if communication has been lost between the monitor computer and the IP telephone set. If the answer is yes, operations are terminated in block 809 . In addition to transferring control to block 809 upon communication being terminated between the monitored computer and the IP telephone set, decision block 802 also is responsive to user input to terminate operations. If the answer is no in decision block 802 , control is transferred back to decision block 801 .
Returning to decision block 801 , if the answer is yes, control is transferred to block 803 which accesses the interface database to determine if the particular terminal status information should be presented to the user. As is discussed with respect to FIG. 9 , the user or system administrator has the capability of determining which terminal status information will be presented to the user as well as how often a particular type of terminal status information must occur before an instance of the terminal status information is presented to the user. If the answer is no in decision block 803 , control is transferred back to decision block 801 . If the answer is yes in decision block 803 , control is transferred to decision block 804 which determines from the interface database if the terminal status information is to be presented by the monitor computer or transmitted to the IP telephone set for presentation to the user. If the answer in decision block 804 is that the monitor computer should present the information, block 805 accesses the encoded audio message from the interface database along with the audio driver type that is to be utilized, and block 806 transmits the terminal status information to the audio driver of the monitor computer for playout. If the decision in decision block 804 is that the terminal status information is to be presented in audio form to the user on the IP telephone set, block 807 accesses the encoded audio message from the interface database along with the audio driver type that is to be utilized on the IP telephone set. Block 808 then sends a message that contains the encoded audio message and the audio driver type to the audio control routine of the IP telephone set before transferring control back to decision block 801 .
Returning to FIG. 7 , if the answer in decision block 702 is yes that the user interface must be tailored, control is transferred to block 902 of FIG. 9 . FIG. 9 illustrates the operations performed by an embodiment in gathering the options of a user wants visual information communicated to them with audio messages. The audio messages can be voice messages or other audio sounds. For example, if the user is talking on one call but has a second call on hold, the user may choose to have the fact that the second call is on hold presented to them as an audio tone or as a voice message. In addition, the user can specify their preference for how often they should receive an audio message with respect to the call on hold. The preference data comprises the various visual messages that can be transmitted to the users IP telephone set and the options that the user has to tailor the resulting audio messages. The interface may be tailored to each individual user or a system administrator may establish one standard interface. In one embodiment, if the system administrator is determining the interface, then, the preference information and accompanying options would be presented in a visual table or other means well known to those skilled in the art. If the information is presented to each user, then in one embodiment the preference information with options is presented as a voice message and the user would select options by responding with voice responses. The voice responses would be interpreted using well known voice-to-text software routines. After receiving control from decision block 702 , block 902 access the preference data for a particular IP telephone set, and block 903 selects the first preference as the selected preference to be presented to the user by block 904 . Block 906 receives the user's response and converts this response to text and verifies that it is a correct response. Block 907 then stores the received response in the interface database. Decision block 908 determines if there are any preferences that remain to have options selected. If the answer is yes, control is transferred to block 909 . Block 909 selects the next preference from the preference data and transfers control back to block 904 . If the answer in decision block 908 is no, control is transferred back to block 703 of FIG. 7 .
FIG. 10 illustrates, in block diagram form, one embodiment of a monitor computer. Processor 1002 provides the overall control for the functions of a monitor computer by executing programs and storing and retrieving data from memory 1001 . A processor such as processor 1002 may also be referred to as a central processing unit or a computer. Processor 1002 connects to WAN 111 or 204 via interface 1003 . Processor 1002 interfaces to user input device 1011 via interface 1007 and connects to display 1019 via interface 1009 . Processor 1002 interfaces to an IP telephone via interface 1021 . Processor 1002 performs the operations of a monitor computer by executing the routines illustrated in memory 1001 .
Operating system 1012 provides the overall control and the necessary protocol operations. Operating system routine 1012 provides all control functions required to implement the TCP/IP protocol as is well known to those skilled in the art. Data is stored in data block 1013 . Interface database 1016 stores preferences and options that define the user interface. Overall control is performed by control routine 1016 . The communication and control of the various interfaces illustrated in FIG. 10 is provided by interfaces routine 1017 . Audio driver 1018 controls the reproduction of sounds.
The monitor computer illustrated in FIG. 10 may be a personal computer, personal digital assistant (PDA), cell phone, music player, or a specially designed device. In addition, the monitor computer may not have all of the elements illustrated in FIG. 10 . For example, elements 1004 , 1006 , 1009 , and 1019 or some combination of these elements may not be present.
In another embodiment, FIG. 11 illustrates IP network 1101 interconnected to a circuit switched telephone network (CSTN) 1121 via gateways 1116 - 1118 . Circuit switched telephone network 1121 is providing service for devices 1127 or 1129 . IP network 1101 is providing service for terminals 1131 - 1132 . One skilled in the art could readily see that there could be a multitude of devices being interconnected by IP network 1101 . Such devices may be, but are not limited to, computers, voice messaging systems, and instant messaging systems. Similarly, circuit switched telephone network 1121 could also be interconnecting a variety of telephone types and terminal types and systems and switch nodes 1122 - 1126 may be PBX's or central office switches.
IP network 1101 utilizes the session initiation protocol (SIP). SIP is defined in the Internet Engineering Task Force (IETF) Request for Comments (RFC) 3261 “SIP: Session Initiation Protocol”, June, 2002. SIP solves the general problem of finding “dialed” endpoints and exchanging critical parameters which endpoints must agree on in order to establish media sessions (calls) across IP network 1101 . The SIP protocol supports the establishment of voice-only sessions or multimedia sessions. SIP endpoints (such as IP communication terminals 1131 and 1132 ) control the supported media types by accepting or rejecting offered media streams. Once the session parameters are exchanged, the endpoint devices send session data directly to each other without using SIP utilizing the RTP protocol to route directly through routers such as routers 1112 - 1114 .
SIP has a generalized address structure that supports “dialing” by URL (like an email address) or “dialing” by a number (like a PBX or Public Switched Telephone Network number). This generalized SIP addressing structure is a powerful aspect of SIP service as it effectively bridges circuit-switched and IP domains into a converged addressing domain.
SIP proxies (such as proxies 1102 - 1109 ) operating in autonomous network domains interpret the “dialed” addresses and route session requests to other proxies or endpoints registered within the domain. Greater detail on the operations of the system illustrated in FIG. 11 operating using the SIP protocol can be found in U.S. patent application Ser. No. 11/217,531 filed Sep. 1, 2005, which is assigned to the same assignee as the present patent application and is hereby incorporated by reference.
FIG. 12 illustrates, in block diagram form, greater details of IP communication terminal 1131 . The other communication terminals of FIG. 11 are similar in design. Block 1134 provides the functions of handset 423 , visual display and buttons 412 , and speaker phone 406 of FIG. 4 . Direct link interface 1151 provides the interface to the monitor computer. IP network interface 1149 provides the interface to the IP network.
Within memory 1136 , the functions of block 1137 - 1139 have already been described in the incorporated patent application. Blocks 1141 - 1147 perform functions as described for blocks 414 and 408 - 422 of FIG. 4 . As is well known by those skilled in the art, for peer-peer communication between telecommunication terminals, call processing routine 1148 in addition to performing all of the call processing functions also generates the terminal status information that is used to indicate the terminal status to the user and is communicated to terminal status control 1142 which performs the operations illustrated in FIG. 5 . Call processing routine 1148 may generate more terminal status information than can be displayed by the visual portion of user interface 1134 . However, call processing routine 1148 will transmit all of the terminal status information to terminal status control routine 1142 so that it can be presented as audio information to the user of IP communication terminal 1131 .
With respect to monitor computer 1128 providing audio terminal status information for IP communication terminal 1131 , IP communication terminal 1131 and monitor computer 1128 operate in a manner similar to that described for monitor computer 118 providing audio terminal status information for IP telephone set 112 of FIG. 1 .
When the operations of an IP telephone set or monitor computer are implemented in software, it should be noted that the software can be stored on any computer-readable medium for use by or in connection with any computer related system or method. In the context of this document, a computer-readable medium is an electronic, magnetic, optical, or other physical device or means that can contain or store a computer program for use by or in connection with a computer related system or method. The IP telephone set or monitor computer can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “computer-readable medium” can be any means that can store the program for use by or in connection with the instruction execution system, apparatus, or device. For example, the computer-readable medium can be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: a portable computer diskette (magnetic), a random access memory (RAM) (electronic), a read-only memory (ROM) (electronic), an erasable programmable read-only memory (EPROM, EEPROM, or Flash memory) (electronic), an optical fiber (optical), and a portable compact disc read-only memory (CDROM) (optical).
In an alternative embodiment, where IP telephone set or monitor computer is implemented in hardware, IP telephone set or monitor computer can be implemented with any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.
Of course, various changes and modifications to the illustrated embodiments described above will be apparent to those skilled in the art. These changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intending advantages. It is therefore intended that such changes and modifications be covered by the following claims except insofar as limited by the prior art.
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A method and apparatus provide terminal status information by a telecommunication terminal as audio information by generating terminal status information by a telecommunication terminal; establishing a direct connection by a monitor computer to the telecommunication terminal via a direct link to the telecommunication terminal; transmitting the generated terminal status information to the monitor computer by the telecommunication terminal via the direct link; converting the generated terminal status information to audio terminal status information by the monitor computer; and presenting the audio terminal status information to a user of the telecommunication terminal. In addition, the method and apparatus establish a firewall by the telecommunication terminal to prevent the monitor computer from communicating on a network to which the telecommunication terminal is connected whereby the monitor computer is also denied access to other devices connected to the network.
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BACKGROUND
[0001] The present exemplary embodiment relates to an automotive vehicle airbag. It finds particular application in conjunction with a curtain airbag and more specifically with a mounting structure for a curtain airbag, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other similar applications.
[0002] Modern vehicles are designed to provide a substantial degree of safety to passengers. One way in which this is accomplished is by including air bags to cushion the passengers during collisions. Air bags were first employed in front of either the driver, front seat passenger or both. Side curtain air bags have also been introduced and protect the vehicle occupants from injury during a side impact collision, rollover collision, or other accident where the passengers are more likely to move laterally.
[0003] Because a side curtain airbag must cover more area that a typical dashboard air bag, the side curtain air bag is larger in size. However, such an air bag must be inflated at a speed that is comparable to a dashboard-configured air bag. As a result, the inflator size and gas output velocity used for the side curtain air bag is typically much larger than that of a dashboard-configured inflator and must be strategically placed. Also, because the side curtain air bag is larger than dashboard-configured airbags, the direction of the deployment must be controlled to optimize its effectiveness during a collision. Controlling placement and deployment direction is rendered more difficult due to limited space along a vehicle's roofline, where the air bag is stored.
[0004] Unlike dashboard mounted air bags that deploy directly toward a vehicle occupant, it is desirable for a side curtain air bag to deploy downward, and as close to the side of the vehicle interior wall as possible. This path avoids an inadvertent collision with the vehicle occupant while the airbag is in the process of deploying and also ensures the most significant coverage.
[0005] One exemplary side curtain airbag assembly is shown in FIG. 1 . Particularly, the airbag system includes an airbag module 10 that principally consists of an airbag 11 (illustrated in a deployed condition), a tension cloth 12 attached to a front end portion of the airbag 11 , a diffuser pipe 13 and an inflator 14 . The airbag 11 is adapted to inflate and deploy into a curtain-like shape along a side wall of the passenger compartment when it is supplied with gas.
[0006] A curtain airbag is typically attached to a vehicle roof rail along a vehicle interior side portion above a door opening of the vehicle body. In a normal state (when the curtain airbag is not deployed), the lower side of the curtain airbag is covered with a terminal portion of roof lining on a vehicle interior side. When an impact caused by collision or the like is experienced, the curtain airbag is unfolded downward from the roof side portion by the high-pressure gas (inflating gas), to form a passenger protective wall between the passenger and the vehicle body side portion. However, during a side impact, it is feasible for the vehicle side pillar (e.g. the vehicle b-pillar) or the pillar garnish to deform, wherein the side curtain airbag deployment could be effected by the displaced pillar or pillar garnish.
[0007] It would be desirable to provide a curtain air bag mounting arrangement wherein the air bag can be deployed within the passenger compartment with minimal likelihood of the airbag being undesirably impacted by a vehicle pillar or pillar garnish in the event the vehicle frame is distorted by the impact.
BRIEF DESCRIPTION
[0008] Various details of the present disclosure are hereinafter summarized to provide a basic understanding. This summary is not an extensive overview of the disclosure and is neither intended to identify certain elements of the disclosure, nor to delineate scope thereof. Rather, the primary purpose of this summary is to present some concepts of the disclosure in a simplified form prior to the more detailed description that is presented hereinafter.
[0009] According to a first embodiment, an arrangement structure for a curtain airbag, which includes an airbag cushion disposed along a roof side rail of a vehicle having a side pillar, and adapted to be inflated in a curtain-like manner during a side-impact vehicle collision is provided. The arrangement structure includes an airbag bracket for attaching the airbag to the vehicle body, and a support member having a first end secured to the vehicle side pillar and a second end receiving the airbag bracket.
[0010] According to a second embodiment, an automotive vehicle including a passenger restraint assembly having a side pillar, a roof rail, and a side curtain airbag assembly adapted to be inflated in a curtain-like manner during a side-impact vehicle collision is provided. A bracket secures the side curtain airbag assembly directly to the side pillar of the vehicle. The side curtain airbag assembly includes a mounting frame having a region joined to the bracket and a chamber configured to receive the folded side curtain.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side view showing a passenger car equipped with a prior art side cushion airbag;
[0012] FIG. 2 is a perspective view of an automotive vehicle side pillar and inner roof rail in the area in which a side curtain airbag is positioned;
[0013] FIG. 3 is a side cross-section view taken along line 3 - 3 of FIG. 2 ;
[0014] FIG. 4 is a perspective view of the vehicle side pillar and inner roof rail of FIG. 2 wherein the side pillar garnish and the roof lining have been removed;
[0015] FIG. 5 is a schematic illustration of how the side curtain airbag mounting assembly of the present disclosure helps to maintain proper alignment of the side curtain airbag for unimpeded deployment; and
[0016] FIG. 6 is a schematic illustration of a seat belt attachment plate modified to include a side curtain airbag support bracket.
DETAILED DESCRIPTION
[0017] Current technology may not maintain a desirable relationship between a side curtain airbag, the vehicle side pillar, and the side pillar garnish during a crash. The result is that current side curtain airbags are being designed to deploy more inboard to clear the garnish during a crash. A more inboard trajectory can deploy in the direction of an occupants head and/or become hung up on a vehicle head rest. The present disclosure sets forth a mechanism of attaching a side curtain airbag to a vehicle which maintains its preferred placement adjacent the roof rail and minimizes the likelihood that a displace side pillar garnish will influence proper deployment.
[0018] A first exemplary embodiment will be described with reference to FIGS. 2-4 . Turning first to FIG. 2 , a vehicle interior side wall 2 is depicted. The vehicle side wall 2 is adjacent to a passenger seat 4 . Vehicle side wall 2 includes a garnish 6 overlying a vehicle side pillar (not visible), and a roof lining 8 overlying an inner roof rail (not visible). Also visible is a seat belt slider garnish 9 , behind which can be disposed a D-ring attachment assembly (not visible) that is secured to the vehicle side pillar.
[0019] Referring now to FIGS. 3 and 4 , an airbag module 10 containing a curtain style airbag is secured to a vehicle by a support member 12 and an airbag bracket 14 . The support member 12 in combination with the airbag bracket 14 position the airbag module 10 between the roof lining 8 , a roof arch stiffener 16 and a roof rail 18 .
[0020] Since the airbag module 10 is similar to what is conventional art, a detailed description thereof will be omitted. Similarly, although a particular airbag bracket configuration is depicted herein, the intent of the disclosure is not believed to be limited to that specific design. Rather, it is anticipated that a variety of airbag bracket shapes can benefit from the present disclosure.
[0021] The support member 12 includes a first end 20 fixed to a side pillar 22 of the vehicle and a second end 24 disposed between the roof arch stiffener 16 , roof rail 18 , and roof lining 8 . The side pillar can be, for example, either or both of what are typically referred to as the vehicle B and/or C pillar.
[0022] Support member 12 can be formed of any suitable material, of which steel, aluminum or fiber reinforced plastic are examples. In addition, although one specific airbag bracket and one specific airbag module is depicted, it is envisioned that the support member 12 of the present disclosure is functional with most if not all traditional airbag modules and their associated airbag bracket(s).
[0023] The first end 20 of support member 12 can be attached to the side pillar 22 by any means known in the art, including for example spot welding or bolting. In the event bolting is utilized, it may be desirable to perform the attachment using existing through holes, such as those used for attachment of a seat belt assembly. In fact, it is envisioned that the present support bracket can form a further element of a seat belt D-ring adjustment bracket (see FIG. 6 ; described herein below).
[0024] The support member 12 can have a first generally vertical and substantially planar region 30 that is mated to the side pillar 22 . In this regard, the side pillar 22 can have a generally vertical orientation and a generally elongated shape with a generally planar inner surface 32 receiving planar region 30 of the support member 12 . At least a portion of planar region 30 of support member 12 and at least a portion of the planar inner surface 32 of side pillar 22 can reside in at least substantially parallel planes. As used herein, the term planar is intended to encompass a planar region 30 having edges 31 which are at least substantially coplanar. Moreover, it is envisioned that the support member 12 could include a protrusion 33 that is received within a channel 35 formed in side pillar 22 . This configuration can provide increased torsional strength in each of the side pillar 22 and the support member 12 .
[0025] Alternatively, the surfaces of the side pillar and support member which are in contact in the region of the bolted or welded connection may not be generally planar but can include complimentary surfaces which facilitate the formation of a desirable interface. For example, it is envisioned that the support member can be in the form of a tube received within a correspondingly shaped channel in the side pillar.
[0026] Support member 12 also includes an angled intermediate wall 34 which joins planar region 30 to a head region 36 . Head region 36 can be shaped to cooperatively mate with a portion of airbag bracket 14 . Angled intermediate wall 34 can be tangential to region 30 of the support member or may have an angle departing from 90 degrees. Head region 36 which receives airbag bracket 14 can similarly be angled relative to intermediate wall 34 . According to an exemplary embodiment, the included angle “A” between region 30 and wall 34 can be at least substantially the same as the included angle “A” between head region 36 and wall 34 . In this manner, region 30 and head region 36 can lie in at least substantially parallel planes.
[0027] The airbag bracket 14 can include a generally vertical area 40 contacting the first planar region 30 of the support member 12 . The airbag bracket 14 can be bolted 42 (or otherwise secured via welding for example) at this point of contact. The airbag bracket 14 can further include generally horizontally extending shelves 44 and 45 defining a receptacle 46 that receives and retains airbag module 10 . Head region 36 of the support member 12 can include at least several points of contact (see 50 and 52 ) with a rear side 54 airbag bracket 14 adjacent to the area in which the receptacle 46 is formed to provide mechanical support thereto. In this manner airbag module 10 can best retain its alignment with the longitudinal axis of the side pillar during displacement thereof.
[0028] With particular reference to FIG. 5 , the benefit of maintaining alignment between the side pillar of the vehicle and the airbag module is visually depicted. Particularly, an original position of side pillar 122 , roof rail 118 , roof arch stiffener 116 , side pillar garnish 106 , and a side curtain airbag containing bracket 114 are depicted in dashed lines. What is shown in dashed lines is a traditional approach to attachment of a side curtain airbag device where the airbag bracket 114 is bolted (see bolt 125 ) to the roof rail 118 .
[0029] As demonstrated by arrow A, in an original position, release of the airbag from module 110 travels to the vehicle inboard side of side pillar garnish 106 to provide effective lateral passenger protection. However, if the vehicle were to experience a side impact force in a direction depicted by arrow I, the side pillar 122 ′ and the side pillar garnish 106 ′ can be forced inwardly (shifted components are depicted in solid line). Since the airbag bracket 114 is affixed to the roof rail 118 , and the roof rail 118 can be prevented from significant inward deformation by roof arch stiffener 116 , the airbag bracket 114 does not shift inward to the same extent as the side pillar 122 and side pillar garnish 106 . As demonstrated by arrow A, the shifted side pillar garnish 106 ′ can prove to be an impediment to proper airbag deployment. More particularly, the roof arch stiffener can prevent the inner roof rail from deforming to the same extent as the side pillar and side pillar garnish, causing miss-alignment of the side curtain airbag bracket and the pillar garnish.
[0030] However, by utilizing support bracket 112 to join side curtain airbag bracket 114 ′ directly to the side pillar 122 ′, the airbag bracket 114 ′ travels inboard in conjunction with the force I. Accordingly, the proper deployment relationship between the airbag and the side pillar garnish 106 ′ can be maintained and the side curtain airbag will still properly deploy within the passenger compartment. This relationship between airbag deployment and the inwardly shifted position of the side pillar garnish 106 ′ can be discerned from the direction of arrow “A′”. As a result, the airbag can be rapidly and stably deployed into the automobile to cover the entire inner side part of the automobile, thereby protecting a driver/passenger from injury.
[0031] Referring now to FIG. 6 , an alternative embodiment of the present disclosure is provided. Particularly, a common seat belt assembly includes a seat belt anchor affixed to a side pillar of a vehicle. A typical arrangement may provide for an adjustable D-ring and may include a button assembly, a rail, a base, a slider and a plate. According to the present disclosure, it is contemplated that a seat belt assembly may include an elongated rail 200 that is affixed to the vehicle side pillar by a pair of bolts 201 . The rail 200 can include a series of openings 202 that are adapted to selectively receive the components of the seat belt assembly such as the pin of the button assembly. In accord with the present disclosure, the elongated rail 200 of the seat belt assembly can be manufactured to include a support bracket 212 constructed in a similar manner as the earlier describe support bracket(s). Particularly, support bracket 212 can include a projection 214 configured to be received within a recess in the side pillar and through holes and/or integral nuts 216 situated to receive bolts from an associated airbag bracket. A first bend 218 and a second bed 220 can lead to a first planar segment 222 suitable for receiving a rear surface of an airbag bracket. A rounded terminal portion 224 can similarly provide points of contact in support of the horizontal wall of the airbag bracket (see 44 of FIG. 3 ).
[0032] Advantageously, the present disclosure provides a side curtain airbag attachment that helps to maintain the relative relationship of the airbag, side pillar, and the pillar garnish during a vehicle side impact. The present support bracket helps to maintain a desired spacial relationship between the side pillar, side pillar garnish, and airbag allowing the side curtain airbag to deploy correctly.
[0033] The exemplary embodiment has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
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A structure for securing a curtain airbag to a vehicle including an airbag cushion disposed along a roof side rail of a vehicle having a side pillar, and adapted to be inflated in a curtain-like manner during a side-impact vehicle collision. The structure includes an airbag bracket for attaching the airbag to the vehicle body, and a support member having a first end secured to the vehicle side pillar and a second end receiving the airbag bracket.
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CLAIM OF PRIORITY AND CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application entitled “APPARATUS AND METHOD FOR REDUCING POWER AND NOISE THROUGH REDUCED SWITCHING RECODING IN LOGIC DEVICES,” Ser. No. 09/501,044, filed Feb. 9, 2000, which is now pending and is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention generally relates to data transmission, and more particularly, to reducing noise production and power consumption using reduced switching recoding in monotonic logic device.
2. Description of Related Art
Currently, many arithmetic operations in present processor implementations are accelerated by utilizing a floating-point processor. These floating-point processors can include multipliers using radix multiplication and carry save adders to increase the performance of multiplication operations.
Generally, there are two popular stages of radix multiplication for carry save adders. High radix multiplication (radix 8 or greater) and low radix multiplication (radix 4 or lesser). High radix multiplication has the advantage of requiring fewer partial products to be generated and summed, however, high radix multiplication also requires that complex multiples of the X operand to be generated. Low radix multiplication (radix 4) is therefor a preferable implementation for executing multiplication due to the simple multiples of the X operand to be generated.
Illustrated in to FIG. 1A, is the radix 4 booth recoding multiplication table 2, the 3 multiplier bits and X operand multiples. As can be seen for radix 4 booth recoding multiplication, only the simple multiples of zero, 1X and 2X are required for the operand. As it is known in the art, a multiple of a number can be easily generated for the zero, one and two multiples. A zero multiple requires only that the value be reset, zeroed out or cleared out. A negative one multiple requires that the complement of the operand be obtained. A multiple of two for a number is easily generated for the number by performing a left shift by one position on the number. A negative multiple of two times a number is obtained by acquiring the complement of the multiple of two number.
Illustrated in FIG. 1B is a table 3 illustrating the traditional domino encoding method for operand multiples, that is normally implemented in radix 4 circuitry. As can be seen, traditional domino encoding requires that 2 of 5 wires be enabled to indicate the proper operand multiples: 0, ±1X or ±2X radix 4 output, as shown in the radix 4 multiplication table 2 (FIG. 1 A). For power and noise reasons, it is desirable to reduce the number of wires routed over the carry save adder array and the switching activity of these wires.
Illustrated in FIG. 1C is a block diagram of a possible example of a multiplexer circuit 14 that utilizes a traditional domino encoding technique illustrated in FIG. 1B to output a final product. The circuit 11 is comprised of 0 times the multiplier 12 , 1 times the multiplier 13 , and 2 times the multiplier 14 signals. All these signals ( 12 - 14 ) are utilized as input into the 3:1 MUX 15 . The 3:1 MUX 15 accepts the three multipliers 12 , 13 and 14 signals as input and has signal lines 16 (A-C) to select the appropriate output.
Upon using the proper selection lines 6 (A-C), the proper input signal 12 , 13 , or 14 is output of the 3:1 MUX 15 and input into the exclusive or “XOR” 18 . The “XOR” 18 accepts the correct multiplier signal from the 3:1 MUX 15 , and a sign signal 17 to output the appropriate output on line 19 . A schematic of the radix 4 booth encoded multiplexer 15 is herein defined in further detail with regard to FIG. 1 D.
Illustrated in FIG. 1D is a schematic of the radix 4 booth encoded multiplexer 15 with 2 of 5 encoding, as shown in FIG. 1 C. As shown in FIG. 1D, the radix 4 booth multiplexer with 2 of 5 encoding of the prior art, requires 22 transistors for the circuit in 4 series of N-fets to generate the output. This 4 high N-fet stack can be slow and does require significant loading on the lines to preserve the correct values.
Illustrated in FIG. 1E is a table 21 illustrating a carry save adder array multiplier operation. Emphasized are the partial products generated during the multiplication operation. Portions of the partial products generated are considered non-critical drop-off bits 26 . A non-critical partial product drop-off bit 26 , is best described as a bit that is determined (i.e. fixed) very early in the cycle time of the overall logic device operation. Since this non-critical partial product drop-off bit 26 is determined very early in the cycle time of the overall device operation, it quite often must be carried a great distance and for a long period of time to be utilized in the final product.
For example, in a carry save adder array multiplier for large multiplicands and multipliers (i.e. 64 bit and larger), a great number of non-critical partial product bits can be produced. These large number of non-critical of partial product bits can cause wire routing problems during designed. Also, a large number of non-critical of partial product bits 26 can cause data errors due to the switching activity of the large number of wires. As discussed above, the non-critical partial product bits 26 can cause problems for circuit designers. Therefore, it is desirable to reduce the number of wires routed and the switching activity of these non-critical partial product drop off bits wires over the carry save adder array multiplier and other monotonic logic devices.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.
SUMMARY OF THE INVENTION
The present invention provides an apparatus and method for reducing noise production and power consumption through reduced switching recoding of signals in monotonic logic devices.
Briefly described, in architecture, the apparatus can be implemented as follows. The apparatus includes a recode circuitry that receives and recodes a monotonic logic device signal received from a first logic circuit in a logic device, into a reduced switching activity signal. The recode circuitry sends the reduced switching activity signal to a second logic circuit. A decode circuitry receives and decodes the reduced switching activity signal back into a monotonic logic device signal. The decode circuitry then sends the monotonic logic device signal to a second logic circuit in the logic device.
The present invention can also be viewed as providing method for reducing noise production and power consumption through reduced switching recoding of signals in monotonic logic devices.
In this regard, the method can be broadly summarized by the following steps: (1) receiving a monotonic logic device signal from a first logic circuit; (2) converting the monotonic logic device signal into a reduced switching activity signal; (3) transmitting the reduced switching activity signal; (4) receiving said reduced switching activity signal; and (5) converting the reduced switching activity signal back into a monotonic logic device signal.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1A is a multiplication table for radix 4 booth encoding including three multiplier bits and the operand multiplier.
FIG. 1B is a table illustrating the traditional domino encoding for radix 4 partial products multiplexer.
FIG. 1C is a block diagram illustrating a radix 4 booth multiplexer with 2 of 5 encoding with the traditional domino encoding method as shown in FIG. 1 B.
FIG. 1D is a schematic of an example of a radix 4 booth multiplexer, as shown in FIG. 1C, using the 2 of 5 encoding as shown in FIG. 1 B.
FIG. 1E is a table illustrating an example of a prior art carry save adder array multiplier operation generating non-critical drop-off bits.
FIG. 2 is a table illustrating a new encoding method for a booth encoder multiplexer of the present invention that reduces switching activity of lines by 50% over traditional domino encoding.
FIG. 3A is a block diagram illustrating a multiplexer that processes the signals generated by utilizing the new encoding method of the present invention.
FIG. 3B is a schematic of a possible example of the radix 4 booth encoded multiplexer of the present invention, as shown in FIG. 3 A.
FIG. 4 is a block diagram illustrating the operation of a carry save adder array multiplier utilizing the new encoding method of the present invention.
FIG. 5A is a table illustrating the encoding of the present invention with regard to PKG recoding.
FIG. 5B is a block diagram illustrating a mousetrap logic encoding circuit for P-propagate code in a PKG recoding.
FIG. 5C is a block diagram illustrating a mousetrap logic encoding circuit for K-kill code in a PKG recoding.
FIG. 5D is a block diagram illustrating a mousetrap logic encoding circuit for the G-generate code in a PKG recoding.
FIG. 6A is a schematic of a possible example of a PKG recoder circuit for generating the P-propagate term of the present invention.
FIG. 6B is a schematic of a possible example of the PKG recoder circuit for generating the G-generate and K-kill terms of the present invention.
FIG. 7A is a block diagram illustrating the mousetrap logic decoded equivalent of a P-propagate code, which is equivalent to the sum high signal.
FIG. 7B is a block diagram illustrating a decoder circuit for decoding a sum low signal in mousetrap logic from a PKG encoded signals.
FIG. 7C is a block diagram illustrating the mousetrap logic decoded equivalent of a G-generate code, which is equivalent to the carry high signal.
FIG. 7D is a block diagram illustrating a decoder circuit for decoding a carry low signal in mousetrap logic from a PKG encoded signals.
FIG. 8A is a schematic of a possible example of a decoder circuit of the present invention, for generating a sum low signal from PKG encoded signals.
FIG. 8B is a schematic of a possible example of a decoder circuit of the present invention, for generating a carry high signal from PKG encoded signals.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the description of the invention as illustrated in the drawings. While the invention will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed therein. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the invention as defined by the appended claims.
Illustrated in FIG. 2 is a table 30 illustrating the reduced switching recoding method of the present invention. The reduced switching recoding method of the present invention reduces switching activity of signal lines, by 50% over the traditional domino encoding method of the prior art. In comparing the reduced switching recoding method table 30 with the traditional domino encoding table 3 (FIG. 1 B), it is evident that each of the five operand multiples for radix 4 output, can be represented by a single wire utilizing the reduced switching recoding method of the present invention. While the description of the present invention is illustrated with regard to traditional domino logic, it should be understood that the reduced switching recoding apparatus and method of the present invention can be utilized with any type of monotonic logic device or signal. Monotonic logic type modules, devices or signals include but are not limited to, dynamic logic (including Domino, NORA, Zipper CMOS logic and the like).
While the traditional domino encoding method of the prior art requires a signal line to indicate a positive or negative sign and one signal to indicate the operand multiple. In utilizing the reduced switching recoding method of the present invention, switching activity is reduced by half, along with providing a significant power savings. Also, by reducing the switching activity of heavily loaded selection lines by 50%, the reduced switching recoding method of the present invention also reduces noise.
Illustrated in FIG. 3A is a block diagram of a possible example of a multiplexer 40 that processes the signals generated by utilizing the reduced switching recoding method of the present invention. As seen in FIG. 3A, the resulting multiplexer 40 A is greatly simplified from the prior art multiplexer 15 (FIG. 1C) using traditional domino encoding representation. One example of a schematic circuit for the simplified multiplexer 40 A is herein defined in further detail with regard to FIG. 3 B.
Illustrated in FIG. 3B is a schematic of a possible example of the radix 4 booth encoded multiplexer 40 B of the present invention. The radix 4 booth multiplexer 40 B of the present invention has a comparable number of transistors as the radix 4 booth multiplexer 15 (FIG. 1D) with 2 of 5 encoding. However, the significant enhancement to the radix 4 booth multiplexer 40 B of the present invention, is that there are at a maximum only 3 transistors in series. The reduction of the number of transistors in series by 25%, lowers the capacitance for the circuit by the same 25%. This incurs less load per input and output wire.
Illustrated in FIG. 4 is an example of a carry save adder multiplier 50 , including the reduced switching recoding method of the present invention. The example shown in this block diagram uses a PKG recoding circuit 60 to recode non-critical drop off bits, to illustrate another application of the reduced switching recoding method of the present invention. The carry save adder multiplier 50 operates in much the same manner as the carry save adder multiplier operation described above with regard to FIG. 1 E.
Input into the carry save adder multiplier 50 , is the traditional domino encoding multiplicand operand 51 . Also input into the carry save adder array multiplier 50 is a multiplier operand 53 that is booth encoded prior to input. In these operands 51 and 53 , are utilized by the carry save adder array logic 52 to generate the final product 54 . Also shown, are the non-critical partial product bits 56 (A-C) described above with regard to FIG. 1 E. As discussed above, the non-critical partial product bits 56 (A-C) can cause problems for circuit designers. However, the PKG recoding of the non-critical partial product bits 56 (A-C) can solve many problems confronting circuit designers.
The PKG recoding circuit 60 of the present invention, operates by having the non-critical partial product drop off bits 56 (A-C), input into a PKG recoder 65 . The PKG recoder 65 recodes the traditional domino encoded numbers into PKG recoded values as discussed herein with regard to FIGS. 5 (A-D).
These PKG recoded values are sent over link 67 to a possible PKG decoder 68 . The PKG decoder 68 decodes the PKG recoded values into traditional domino encoded numbers as discussed herein with regard to FIGS. 7 (A-D). The PKG decoder 68 decodes the PKG recoded values back into traditional domino encoded numbers for further operation in the carry save adder array multiplier 50 .
Using the reduced switching activity encoded apparatus and method of the present invention (i.e. PKG recoding), on the non-critical partial product bits 56 (A-C), can reduce the number of wires must be routed across the carry save adder array multiplier 50 and reduce switching activities of these reduced number of wires.
Illustrated in FIG. 5A is a recoding table 70 illustrating the reduced switching activity encoding of the present invention, with regard to PKG recoding. The example PKG recoding table 70, illustrates the reducing of wiring output of a logic device by recoding the traditional domino encoded sum and carry output signals, from the logic device, as PKG recoded signals P 76 , K 77 and G 78 . As one can see from PKG recoding table 70, the PKG recoding can represent any combination of the sum and carry signal bits with one active signal.
Illustrated in FIG. 5B is a block diagram of a possible example of a mousetrap logic encoding circuit 80 , for propagate code P 76 in a PKG recoding. As shown in FIG. 4B, the propagate code is generated from the mousetrap encoding by taking the logical “AND” operation of sum high 71 and carry low 74 encoded signals in the “AND” logic 81 and the output is then entered into a first input of the OR logic 83. The logical “AND” of the sum low 72 and the carry high 73 is performed in the “AND” gate 82, and the output is then entered into a second input of the “OR” logic 83. The final logical operation utilizing the “OR” logic 83 produces the propagate code P 76 that is equal to the logical “AND” of the sum high 71 & carry low 74 , or the logical “AND” of the sum low 72 & carry high 73 signals.
Illustrated in FIG. 5C is a block diagram of a possible example of a mousetrap logic encoding circuit 90 , for kill code K 77 in PKG recoding. The kill or clear all bits code in the PKG recoding is represented by a logical “AND” of the sum low and carry low mousetrap encoding bits. If both the sum low and carry low bits are enabled, the PKG recoding generates the kill code K 77 , which clears all logic.
Illustrated in FIG. 5D is a block diagram of a possible example of a mousetrap logic encoding circuit 100 , for the generate code G 78 in PKG recoding. The generate code in PKG recoding is constructed utilizing a logical “AND” of the sum high and carry high bits in mousetrap encoding. If the sum high and carry high bits are enabled, the PKG recoding will generate the generate code G 78 that indicates the setting of both bits.
Illustrated in FIG. 6A is a possible schematic 80 B of the example of a P recoder circuit 80 A, as shown in FIG. 5 B. The schematic of the example of a P recoder circuit 80 B, of the present invention, is for generating the P-propagate term 76 .
Illustrated in FIG. 6B is a possible schematic of the example of the K & G recoder circuits 90 A and 100 A respectively, as shown in FIGS. 5C and 5D. The schematics of the example of a K & G recoder circuits 90 B and 100 B respectively, are for generating the G-generate 78 and K-kill 77 terms of the present invention.
Illustrated in FIG. 7A is a block diagram illustrating the mousetrap logic decoded equivalent of a P-propagate code 76 . The sum high signal 71 is depicted as the decoded mousetrap logic equivalent of the P-propagate code 76
Illustrated in FIG. 7B is a block diagram illustrating a possible example of a decoder circuit 130 A for a sum low signal 72 in mousetrap logic encoding. The sum low signal 72 is derived from PKG recoding kill code K 77 and G-generate code 78 signals. The sum low signal 72 is generated by a logical “OR” of the kill code K 77 and G-generate code 78 PKG recoding signals. If either the kill code K 77 or the G-generate code 78 are enabled, the decoder circuit 130 A enables the sum low signal 72 .
Illustrated in FIG. 7C is a block diagram illustrating the mousetrap logic decoded equivalent of a G-generate code 78 . The carry high signal 73 is depicted as the decoded mousetrap logic equivalent of the G-generate code 78 .
Illustrated in FIG. 7D is a block diagram illustrating a possible example of a decoder circuit 150 A for a for a carry low signal 74 in mousetrap logic encoding. The carry low signal 74 is derived from PKG recoding propagate code 76 and kill code K 77 signals. The carry low signal 74 is generated by a logical “OR” of the propagate code 76 and kill code K 77 PKG recoding signals. If either the propagate code 76 or the kill code K 77 are enabled, the decoder circuit 150 A enables the carry low signal 74 .
Illustrated in FIG. 8A is a schematic of a possible example of a decoder circuit 130 B, as shown in FIG. 7B, for generating a sum low signal 72 from PKG encoded signals.
Illustrated in FIG. 8B is a schematic of a possible example of a decoder circuit 150 B, as shown in FIG. 7D, for generating a carry high signal 74 from PKG encoded signals.
While the decoded equivalents of the reduced switching activity signals (i.e. PKG recoding) are shown in FIGS. 7 (A-D) and 8 (A & B), it is contemplated by the inventors that logical operations may be performed on the reduced switching activity signals directly. Since decoding of the reduced switching activity signals is accomplished through such simple logic circuits, a designer may wish to perform logical operations directly with the reduced switching activity signals (i.e. PKG recoding).
Certainly a designer of ordinary skill in the art could produce a gating cell similar to the one shown in FIGS. 5 (B-D)- 8 (A & B) to implement the PKG recoder and decoder of the present invention. The block diagrams of FIGS. 5 (B-D)- 8 (A & B) show the architecture, functionality, and operation of a possible implementation of the system architecture to increase the performance of carry save adder multiplication operations. In this regard, each block represents a module, device, or logic. It should also be noted that in some alternative implementations, the functions noted in the blocks might occur out of the order. For example, two blocks may in fact be executed substantially concurrently, depending upon the functionality involved. It should also be noted that while the description of the present invention is illustrated with regard to traditional domino logic, it is understood that the reduced switching recoding apparatus and method of the present invention can be utilized with any type of monotonic logic type module, device or signal. Monotonic logic type modules, devices or signals include but are not limited to, dynamic logic (including Domino, NORA, Zipper CMOS logic and the like).
It should be emphasized that the above-described embodiments of the present invention, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention and protected by the following claims.
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An apparatus and method provide an apparatus and method for reducing noise production and power consumption in a logic device that uses monotonic logic encoded signals. In particular, the apparatus is accomplished by a recode circuitry that receives and recodes a monotonic logic encoded signal received from a first logic circuit in the logic device, into a reduced switching signal. The recode circuitry sends the reduced switching signal to a second logic circuit. A decode circuitry receives and decodes the reduced switching signal back into a monotonic logic encoded signal. The decode circuitry then sends the monotonic logic encoded signal to a second logic circuit in the logic device. The method is accomplished by receiving a monotonic logic encoded signal from a first logic circuit. The monotonic logic encoded signal is converted into a reduced switching signal and transmitted. The reduced switching signal is received and converted back into the monotonic logic encoded signal.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for forming highly integrated semiconductor devices and, more particularly, a method for forming damascene gate electrodes for highly integrated MOS transistors that includes effectively removing a dummy polysilicon layer.
[0003] 2. Description of the Related Art
[0004] In general, a polysilicon gate electrode and a polycide gate electrode have been used as a gate electrode in sub-0.10 micron devices. However, polysilicon gate are associated with problems such as increases in the effective thickness of the gate insulating layer caused by gate depletion and threshold voltage variations resulting from dopant penetration from p + or n + polysilicon gate to a substrate and/or variations in dopant distribution. Further, it has proven difficult to produce consistent low-resistance conductors having extremely narrow line widths.
[0005] Therefore, metal gate electrodes are being developed as a substitute for the conventional polysilicon gate electrodes. Metal gate electrodes can solve the above-mentioned problems by eliminating the need for dopant in the manufacturing process. Metal gate electrodes, therefore, are able to provide threshold voltages that are symmetric between the NMOS and PMOS regions of a CMOS device by using metals that exhibit a work function located in a mid-band gap of silicon. Such metals include tungsten (W), tungsten nitride (WN), titanium (Ti), titanium nitride (TiN), molybdenum (Mo) and tantalum (Ta).
[0006] However, it has proven difficult to pattern metal gate electrodes. Also, during the subsequent ion implantation process necessary to form the source and drain regions, the surface of the metal film may be damaged. And similarly, the metal film may be subjected to thermal damage during the thermal process after ion implantation necessary to activate the dopants and/or anneal the crystal damage.
[0007] In order to solve these problems, a method has been proposed for forming a metal gate electrode using a damascene metal gate process. In the damascene metal gate process, a polysilicon gate is formed as a dummy gate and then source/drain regions are formed, thereby completing a transistor. The polysilicon gate is then removed and a metal gate is formed using a damascene process.
[0008] [0008]FIGS. 1A to 1 F show a conventional method of forming a damascene metal gate.
[0009] Referring to FIG. 1A, a silicon oxide layer and a polysilicon layer are formed on a wafer ( 10 ), that is, a silicon substrate in a conventional method of forming polysilicon gate electrode and then, the layers are subjected to a patterning process, thereby forming a dummy gate insulating layer ( 11 ) and a dummy gate electrode ( 12 ).
[0010] Subsequently, source/drain regions ( 13 ) are formed by implanting ion impurities and spacers ( 14 ) are formed on the sidewalls of the dummy gate insulating layer ( 11 ) and the dummy gate electrode ( 12 ). Here, the source/drain regions may be formed using a LDD (Lightly Doped Drain) structure by the following steps. Firstly, a dummy gate electrode ( 12 ) is formed and then, source/drain regions are implanted with a low dopant concentration. Sidewall spacers ( 14 ) are then formed and the source/drain regions are implanted a high dopant concentration.
[0011] Referring to FIG. 1B, an interlayer insulating layer ( 15 ) is then formed over the resulting structure. The interlayer insulating layer ( 15 ) is then subjected to a chemical mechanical polishing (CMP) process as shown in FIG. 1C to remove a top portion of the interlayer insulating layer and expose the surfaces of dummy gate electrodes ( 12 ).
[0012] Referring to FIG. 1D, exposed dummy gate electrode ( 12 ) and dummy gate insulating layer ( 11 ) are selectively etched to expose the substrate ( 10 ). The removal of the dummy gate electrode ( 12 ) and the dummy gate insulating layer ( 11 ) produces a trench ( 16 ).
[0013] Referring to FIG. 1E, a thin insulating layer ( 17 ) and a metal layer ( 18 ), such as a tungsten layer, are formed on the interlayer insulating layer ( 15 ) trench ( 16 ). The interlayer insulating layer ( 15 ) is then exposed by CMP process, thereby forming a damascene gate insulating layer ( 19 ) and a damascene metal gate electrode ( 20 ).
[0014] The above-mentioned method of forming a damascene metal gate electrode provides certain advantages by deferring the gate electrode formation until after the transistor source/drain regions have been formed. For example, it is possible to avoid both plasma damage from the ion implantation processes and thermal damage that can occur during the follow-up thermal processes.
[0015] [0015]FIGS. 1A to 1 D show process steps for selectively removing the polysilicon layer forming dummy gate ( 12 ). It is important to prevent damage of sidewall spacers ( 14 ) and the interlayer insulating layer ( 15 ) during the process of removing the polysilicon layer and it is particularly important to prevent damage to the exposed portion of the silicon substrate ( 10 ). Further, all residue from the polysilicon layer must be completely eliminated from the trench ( 16 ).
[0016] [0016]FIGS. 2A and 2B show a conventional method of removing a dummy polysilicon layer for a dummy gate electrode. FIG. 2A shows a conventional method of removing a dummy polysilicon layer using a dry etch process and FIG. 2B shows a method using a wet etch process. In FIG. 2A, the dummy polysilicon layer is etched back and then removed using a plasma etch. FIG. 2B illustrates a method in which the dummy polysilicon layer is removed by a static etch process, that is, by dipping wafers ( 22 ) into a wet chemical etch bath ( 21 ) for a predetermined time.
[0017] However, these conventional methods of removing dummy polysilicon layers have certain problems.
[0018] First, plasma damage is caused on a wafer ( 10 ) when the trench ( 16 of FIG. 1D) is formed by etching a dummy polysilicon layer. Further, a post-process treatment is required to remove polymers generated during the dry etch back process.
[0019] The wet etch process using the wet chemical is preferred to a dry etch process since it prevents plasma damage of substrate and it is an isotropic etch process. However, the wet etch process is advantageous only when the etch chemistry is such that the polysilicon layer is etched much more rapidly than the other layers that are exposed to the etch.
SUMMARY OF THE INVENTION
[0020] Therefore, the present invention has been made in order to solve the above-mentioned problems in the prior art. An object of the present invention is to provide a method for forming a damascene metal gate in which a dummy polysilicon layer is etched rapidly using a spin etch process.
[0021] In order to achieve the above object, the method for forming a damascene metal gate according to the present invention is characterized by the steps of: forming a dummy gate insulating layer and a polysilicon layer for a dummy gate on a wafer; forming an interlayer insulating layer on the wafer having the dummy polysilicon layer; polishing the interlayer insulating layer to expose a top of surface of the dummy polysilicon layer; and wet etching the exposed dummy polysilicon layer using a spin etch process.
[0022] According to the present invention, the dummy polysilicon layer is spin etched by providing wet chemicals to the surface of the dummy polysilicon layer while rotating the wafer.
[0023] Here, the speed of rotation of the wafer is 500 to 2000 rpm and a mixture of HF and HNO 3 is used as the wet chemical at a rate of 1:10 to 1:50 with the temperature of the wet etch chemical solution being between 20 and 100° C.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIGS. 1A to 1 F illustrate conventional manufacturing processes of forming a damascene metal gate.
[0025] [0025]FIGS. 2A and 2B are drawings illustrating alternative etch methods removing the dummy polysilicon layer in a conventional method of forming a damascene metal gate.
[0026] [0026]FIG. 3 illustrates the method of forming a damascene metal gate according to the present invention.
[0027] [0027]FIGS. 4A to 4 C illustrate the manufacturing processes for forming a damascene metal gate according to a preferred embodiment of the present invention.
[0028] [0028]FIG. 5 illustrates a method of removing a dummy polysilicon layer according to the present invention.
[0029] [0029]FIGS. 6A and 6B are electron micrographs of gate regions after removing a dummy polysilicon layer according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The above objects, and other features and advantages of the present invention will become more apparent after reading the following detailed description when taken in conjunction with the drawings.
[0031] Referring to FIG. 3, a dummy polysilicon layer is removed using a spin etch process. The spin etch is a dynamic wet etch process to remove a dummy polysilicon layer by rotating a wafer ( 30 ) and providing wet chemicals to the surface of the wafer ( 30 ) through a chemical provider ( 40 ).
[0032] [0032]FIGS. 4A to 4 C show a method of forming a damascene metal gate according to a preferred embodiment of the present invention.
[0033] First, a dummy gate oxide layer ( 32 ) and a dummy polysilicon layer ( 33 ) are formed on a wafer, i.e., silicon substrate ( 31 ) and etched to form a dummy gate. Sidewall spacers ( 34 ) and source/drain regions are then formed. Subsequently, an interlayer insulation layer ( 36 ) is formed on the surface of the resulting structure. The source/drain regions may be formed in a LDD structure by implanting dopant both before and after the sidewall spacers ( 34 ) are formed.
[0034] Referring to FIG. 4B, a top portion of the interlayer insulating layer ( 36 ) is removed using a CMP process to expose a surface of the dummy polysilicon layer ( 33 ).
[0035] Referring to FIG. 4C, the dummy polysilicon layer ( 33 ) is rapidly removed by rotating a semiconductor substrate ( 31 ) having a dummy polysilicon in accord with FIG. 3 while providing wet chemicals to the surface of the wafer.
[0036] Thereafter, although it is not shown in drawings, the remainder of the dummy gate oxide layer is removed and a damascene gate insulating layer and damascene metal gate are then formed.
[0037] [0037]FIG. 5 is a drawing illustrating a method of removing a dummy polysilicon layer using a spin etch process according to the present invention.
[0038] The drawing shows a flow of wet chemicals on a rotating semiconductor substrate ( 31 ). The direction and length of arrow correspond generally to the direction and velocity of the flow of the wet chemicals. Unlike the conventional method illustrated in FIG. 2B, wet chemicals are coated onto and moved across the surface of the wafer, thereby etching the dummy polysilicon layer ( 33 ). Here, the etch rate depends on the flow speed of etching chemicals and it depends on the rpm (rotation per min) of the semiconductor substrate ( 31 ).
[0039] When a wafer rotates more than 2000 rpm, wet chemicals also move rapidly across the wafer as a result both of the rotation angular velocity and the centripetal angular velocity. In the trench ( 37 ), which is being formed by removing a dummy polysilicon layer, wet chemicals move rapidly to the edges of wafer. When the wafer rotates too rapidly, most of chemicals pass over the damascene trench ( 37 ) and only a part of chemicals flow into the trench.
[0040] The etching chemicals in the trench cause eddy flow due to its rapid flow rate and tend to stagnate in the trench. Therefore, it is impossible to introduce fresh chemical etch solution into the trench and the polysilicon layer in the trench is not removed efficiently.
[0041] When a wafer rotates at the rate of 500-2000 rpm, the dummy polysilicon layer is removed more effectively than provided by rapid rotation or static dip etching. That is, when a wafer rotates at a sufficiently slow rate (500-2000 rpm), the wet etch solution is allowed to flow into the trench ( 37 ) and accordingly, the eddy flow in the trench is reduced. Therefore, it is possible to introduce fresh wet chemical etch solution into the trenches being etched into the wafer surface. Moreover, the chemicals flowing into the trench increase the etch rate of polysilicon layer as a result of the mechanical agitation forces induced by the rotation.
[0042] Table 1 provides a comparison of the conditions for removing a dummy polysilicon layer using a spin etch process of the present invention and conventional wet etch process.
Conventional Spin etching wet etching of the present invention Experimental condition NH 4 OH:H 2 O = 1:2-1:20 HF:HNO 3 = 1:20 Temperature: 86° C. Temperature: 23° C. Dipping into a wet bath Rotation speed of wafer: 500- 2000 rpm (desirably 1400 rpm) Flow rate of chemicals: 0.3-1.3 lpm Etching speed of layers Polysilicon: 90 Polysilicon: 12,000 (Å/min) Thermal oxide layer (SiO 2 ): 0.2 Thermal oxide layer (SiO 2 ): 540 CVD oxide layer (HDP SiO 2 ): 0.3-1 CVD oxide layer (HDP SiO 2 ): 700 Nitride layer (Si 3 N 4 ): 0.3-1 Nitride layer (Si 3 N 4 ): 60 Etching selection ratio Thermal oxide layer (SiO 2 ) is 450:1 Thermal oxide layer (SiO 2 ) is 22:1 to polysilicon layer CVD oxide layer (HDP SiO 2 ) is 90-300:1 CVD oxide layer (HDP SiO 2 ) is 17:1 Nitride layer (Si 3 N 4 ) is 90-300:1 Nitride layer (Si 3 N 4 ) is 200:1
[0043] As shown in Table 1, according to a conventional method, the etching rate for the polysilicon layer is about 90 Å/min at a temperature of 86° C. in a wet etch bath comprising a NH 4 OH+H 2 O solution. However, according to a spin etching of the present invention, the etching speed of polysilicon layer is 12,000 Å/min at a temperature of 23° C. when solution of HF:HNO 3 with a mixture ratio of 1 to 20 is provided at a flow rate of 0.8 lpm (liter per min) and a wafer rotates at a speed of 1400 rpm.
[0044] [0044]FIGS. 6A and 6B are electron micrographs for showing the result when the polysilicon layers of a trench is spin etched for 10 seconds under the experimental conditions of table 1. The FIGS. 6A and 6B are obtained by removing a dummy polysilicon layer of FIG. 4C. Here, FIG. 6A shows a narrow trench of memory cell area and FIG. 6B shows a wide trench of peripheral circuit area. As shown in FIGS. 6A and 6B, polysilicon layers were effectively removed in both the wide trench and the narrow trench at the same time by the present method.
[0045] Referring to Table 1, according to a spin etching of the present invention, the etching selection ratios of polysilicon to oxide and nitride are lowered than that of conventional method. However, it is advantageous in that it has not caused any damage on a substrate.
[0046] And, referring to FIG. 6A and 6B, when the dummy polysilicon layer is removed by spin etching according to the present invention, the wafer does not exhibit any pattern collapse caused by the forces exerted on the rotating wafer.
[0047] In a spin etching process according to the present invention, it is preferred that the rotation speed of wafer is 500 to 2000 rpm, the mixture ratio of HF to HNO 3 in the wet etch solution is 1:10 to 1:50, the flow rate of chemicals is 0.3 to 2.0 liters per minute and a temperature of the chemical etch solution is 20 to 100° C.
[0048] As described above, according to the present invention, a dummy polysilicon layer is removed much more rapidly than is possible with a conventional wet etching process, by using a spin etch process, in which the wafer is rotated as the wet etch chemicals are applied to the wafer surface.
[0049] Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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The present invention relates to a method of forming a damascene gate electrode of highly integrated MOS transistor capable of easily removing a dummy polysilicon layer. The disclosed comprises the steps of forming a dummy gate insulating layer and a polysilicon layer for a dummy gate on a wafer; forming an interlayer insulating layer on the wafer; polishing the interlayer insulating layer to expose a top surface of the dummy polysilicon layer; and wet etching the exposed dummy polysilicon layer using a spin etching process.
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BACKGROUND OF THE INVENTION
This invention relates to protective body armor and more particularly to such body armor which protects the wearer from both sharp objects and bullets.
The use of protective body armor comprising cloth woven from aramid fibers to protect wearers from bullets is known in the art. Commercial cloth is available that is made from an aramid fiber sold by Dupont under the trademark Kevlar. The cloth, depending upon its thickness, provides varying degrees of protection.
In various circumstances the danger of bodily harm is not from bullets, but rather sharp objects such as knives, ice picks and pointed weapons. In particular, in corrective facilities, most attacks against correction officers are made with various types of blades.
Although it has been found that the woven aramid fabric protects from bullets, it does not afford protection from blades which cut the fabric to allow the blade to enter the body or from ice picks which part fibers to permit penetration.
Protective armor must be comfortable to wear. If not, there is a likelihood that it will not be used. Thus, in addition to providing a garment which prevents injury, manufacturers must provide garments which are relatively lightweight and flexible.
Accordingly, it is a purpose of this invention to provide protective body armor which can protect the wearer from thrusts of sharpened objects.
Additionally, it is another purpose of this invention to provide such armor which also protects the wearer from injury caused by bullets.
A further purpose of this invention is to provide protective armor which is worn under an outer jacket or in specially developed pockets of a covering jacket so that it will not be evident on visual inspection that it is being worn.
The requirements of comfort and concealability place great constraints on the design of body armor and thus it is an object of this invention to provide the protective features in a design that is concealable and reasonably comfortable to wear for an extended period.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical panel of this invention showing the two ply arrangement of titanium metal and woven ballistic cloth.
FIG. 2 is a perspective assemblage of a number of panels having the composition of the FIG. 1 panel arranged in overlapping and in butt relationship as they are in a portion of the item of body armor made from the FIG. 1 panels.
FIG. 3 is a cross-sectional view along plane 3--3 of FIG. 2 to show the multi-layer relationship of panels, felted layers and bonding material. FIG. 2 shows only the panels while FIG. 3 shows other layers of the body armor insert.
FIG. 4 is an elevation view, partially broken away, of a front body armor insert to be worn over the front torso of the individual wearing the entire body armor garment.
FIG. 5 is a view similar to that of FIG. 4 except it is of the back insert. Like FIG. 4, FIG. 5 is broken away to show various layers and plies.
FIGS. 6 and 7 are perspective views, partially broken away, of the two body armor inserts in relationship to one another.
FIG. 8 is a cross sectional view along the plane 8--8 of FIG. 4 illustrating a cross section of a "seagull" shaped back-up strip of body armor plate. To clarify the illustration, FIG. 8 shows only the back-up strip plate and does not illustrate the various felted layers and main plates that are behind or in front of the FIG. 8 strip plate.
FIG. 9 is an elevation view similar to that FIG. 4, though somewhat simplified, to show the position of a spacing pad which can be worn under the breasts of a woman guard to partially transfer the weight of the armor from the breasts of the wearer to the rib cage and upper abdomen of the wearer.
FIG. 10 is a cross sectional view along plane 10--10 of FIG. 9 illustrating the structure of the spacer element.
BRIEF DESCRIPTION
In brief, one embodiment of this invention involves the provision of a body armor insert which includes a plurality of armor panels. Each panel is formed of a ply of titanium metal bonded to a ply of cloth woven from aramid fibers. The cloth ply is positioned on the strike side of the panel. These panels are arranged to form an insert. In the insert some of the panel edges overlap and some panel edges are in a butt relationship. A first layer of felted material is bonded across the arrangement of panels on the cloth ply side. A second layer of felted material is bonded across the arrangement of panels on the metal ply side. The felted layers hold the components in position so that each component is free to move relative to the other components to the extent permitted by the felted layers and the overlapping and butt joints. Backup strips of such panels are positioned inward from the butt joints to assure the integrity of the armor. The assemblage is encased in a nylon fabric shell to form the insert.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, each body armor panel 10 of the embodiment shown includes a first ply 12 formed of titanium metal bonded to a second ply 14 formed of woven aramid fibers. The panels 10 are arranged in the body armor insert 16 such that the cloth ply 14 is worn to be on the strike side (that is, outer side) of the insert 16.
A plurality of panels 10 are arranged to form a protective insert. A portion of such an insert is shown in FIG. 2. To form an insert, the panels are placed in various relationships relative to one another. Certain panels, such as panels 10a, 10b and 10c, are positioned with overlapping edges. Certain panels, such as the two panels 10c are positioned such that their edges are in a butt or approximate butt relationship. All of the panels 10 of the insert are oriented such that the cloth ply 14 is on the strike side. Certain of the panels 10 may be bent or curved to better conform to body curvatures.
As shown in FIG. 3, each insert includes a first felted ply 22, composed of aramid fibers in felted form which is bonded to the cloth plies 14 of the panels 10. A second felted ply 24 composed of aramid fibers in felted form is bonded to the titanium plies 12 of the panels 10. Panels 10 in strip form cover the seams formed by abutting edges. These strip panels 10 like the rest of the panels 10 are formed of a titanium ply 12 bonded to a cloth ply 14 made of woven aramid fibers.
A third felted ply 26 composed of aramid fibers in felted form is bonded to the strips 10 and to the second felted ply 24 to hold strips 10 in place and to provide cushioning. The external or strike side of the insert is further from the wearer's body. The third felted ply 26 is closer to the wearer's body. From the orientation of the wearer's body, the strips 10 are outboard of third felted ply 26. The second felted ply 24 is outboard of the strips 10.
The three plies 22, 24 and 26 of felted material extend a minimum of one-quarter inch beyond the edges of the assembly of panels 10 in order to provide an additional degree of comfort and to assure that the edges of the panels 10 do not dig into the torso of the wearer.
The panel edges which overlap do so by close to one inch. This amount has been found necessary to assure that a knife which hits an overlap joint will be travelling parallel to the body surface if it gets through the joint and thus will inflict no wound or only a surface flesh wound. Accordingly, the strip panels 10 have a width of about two inches so as to provide substantially a one inch overlap on either side of the butt joint for the same reasons.
The body armor assemblages are enclosed in a woven nylon shell 27 in order to keep the panels and plies clean. The resulting assemblage with nylon shell is referred to as an insert because it is normally inserted into a rather large pocket arrangement in a shirt or other garment made for the purpose. However, the insert can be worn free of any such outer shell or carrier. It is to be understood in the specification and claims that the reference to the insert is without prejudice to it being used with or without a carrier.
The felted plies 22, 24, 26 are the only components of the insert 16 that hold the panels 10 in their predetermined relationship to one another. Adhesive plies 28 are shown in exaggerated thickness to indicate how the various layers 10, 22, 24, 26 are held together.
Because the various panels 10 are not bonded to one another but rather are held in position solely by the felted plies 22, 24 and 26, the panels 10 are free to move relative to one another to the extent permitted by the felted plies and by the overlapping and butt edges. Thus, the insert is reasonably flexible, capable of conforming to body contours and avoid inhibiting body movement.
The main panels 10 are curved about a vertical, most of them with a radius of curvature of about ten inches. This curvature approximates torso contours so as to provide comfort and also to conceal the fact that the wearer has body armor on. Comfort and concealability are two major objects for body armor. The combination of the curved form of the panels and the flexibility provided by the joints result in enhanced comfort and concealability.
As shown in the FIGs. certain panels such as the panels 10c and 10c' have a butt relationship. It should be understood that this butt relationship does not necessarily mean that the panel edges contact. They are closely spaced to one another usually with a tolerance of about one-eighth of an inch. The strip panels 10 are to assure protection over this butt zone. The reason for the butt relationship is to provide sufficient adjustability for the armor inserts so that they will fit on the body of the wearer in a fashion that makes the armor substantially concealed. Without the butt relationships, the armour would tend to stick out too noticeably along the lines of the butt relationships shown in FIGS. 4 and 5. In order to make the armor concealable under the shirt of the wearer, these butt relationships are necessary. As shown in FIG. 4, the front armor insert 16f has one vertical butt relationship zone 30 that involves six panels and one horizontal butt relationship zone 31 which involves four panels. As shown in FIG. 5 the back armor insert 16b has one vertical butt relationship zone 32 involving eight panels, a first horizontal butt relationship zone 33 involving four panels and a second horitzontal butt relationship zone 34 involving four panels.
The overlapping edge relationships are shown in FIGS. 4 and 5 by dotted lines. For example, the dotted line 36 indicates an edge of the panel 10b which extends under an edge of the panel 10c to create an overlap joint.
In FIGS. 4 and 5 the nylon shell 27 and the felted ply 22 have been broken away over most of the figures so that the main panels 10 are shown. In both cases, the strike side of the panels 10 is shown so that it is the woven aramid cloth 14 surface which is being shown. However, at one small location in FIG. 5, the cloth 14 is broken away to show the underlying titanium ply 12. Both FIGS. 4 and 5 show that each of the inserts 16f and 16b have twelve panels 10 not including the strip panels 10.
To form a protective vest 38 a front insert 16f and a back insert 16b are inserted into large pockets of a cloth garment (not shown) to provide protection to the entire torso including the rib cage and kidney areas.
In a preferred embodiment, the vest 38 has twelve main panels 10 and three strip panels 10 for its front insert 16f. It also has twelve main and eight strip panels 10 for its back insert 16b. It can be provided with a foam pad 40 to prevent pressure being exerted on the breasts of female users (see FIG. 9). Although optimum protection is afforded by a vest with components protecting the entire torso, a lighter weight vest having fewer components, strategically positioned, is usable.
More specifically, in that embodiment, the panels 10a and 10b are approximately 2.5 inches wide by 5.5 inches tall. They overlap one another by one inch. The panel 10c is 6.25 inches wide and 5.5 inches tall. It overlaps panel 10b by one inch. Thus, taking into account their overlap, the three panels 10a, 10b and 10c cover an area nine inches across one-half of the chest. As shown in FIG. 4, the outer corner of the panel 10a is chamfered. These three panels 10a, 10b and 10c are curved about a vertical axis and have a radius of curvature between about eight and ten inches.
Panel 10d is 2.5 inches wide and has a short vertical edge with a height of 1.5 inches and a long vertical edge with a height of 4.75 inches. The connecting sloping edge is thus approximately 4.85 inches. Panel 10e is 6.5 inches wide and 5.5 inches tall with an upper left corner chamfered to continue the sloping line of the panel 10d. Panel 10e overlies panel 10d with a one inch overlap. Both panels 10d and 10e overlie the panels below them with a one inch overlap. The remaining panel 10f is 4.75 inches wide and has a maximum height of 4.5 inches. Its vertical height at the center line 30 is one inch. Panels 10d 10c and 10f are curved about a vertical axis and have a radius of curvature between eight and ten inches. The upper edge of panel 10f may be bent back slightly to avoid a visible edge. Along the line 31, the panels 10e and 10f have an abutting relationship; they do not overlap. A mirror image set of panels is provided to constitute the other half of the front insert 16f. As shown in FIG. 4, the two sets of panels that provide the two halves of the front insert 16f are arranged in an abutting relationship along the vertical line 30.
There are a total of three strip panels used in connection with the front insert 16f to provide additional protection along the abutting zones 30 and 31. These strip panels are a first strip panel 10g which is two inches wide and 5.5 inches tall along the lower portion of the zone 30. A second strip panel 10h is two inches wide and 4.5 inches tall along the upper portion of the zone 30. The lower end of 10h overlaps the upper end of 10g by one inch. Thereby providing a nine inch length of strip panels. A somewhat more complex bowed strip panel 10j is two inches wide and approximately 9.5 inches long. It is arranged behind the zone 31 and extends across the entire front insert 16f. As shown, this strip panel 10j has a somewhat complex "seagull" profile shape so as to conform to a line across the torso of the wearer and to avoid a chicken breast effect. Each half of the panel 10j has a radius of curvature of between eight and ten inches to match the curvature of the panels 10f. The upper portion of panel 10h is creased along a vertical line so as to approximately match the profile of the strip panel 10j at the horizontal zone 31. The strip panels 10h and 10j have an abutting relationship and do not overlap.
The back insert 16b has overlapping end panels 10k and 10m which are each 3.0 inches wide and 6.5 inches tall. A center bottom panel 10n is 6.5 inches by 6.5 inches and overlaps panel 10m by one inch thereby providing approximately a ten inch horizontal distance over the bottom portion of one half of the back insert 16b. The panel 10p is 5 inches tall and overlaps by one inch the panel 10n. The panel 10p is 6.5 inches at its base line and tapers to approximately 5.8 inches along its top at the zone 34. The panel 10q is 3.25 inches high and tapers from 5.8 inches to 5.25 inches. The panel 10r has a 3 inch vertical dimension and continues the edge taper to a small chamfer at the upper corner which results in a 4 inch horizontal dimension at the top of the panel 10r. As shown in FIG. 5, the panels 10p, 10q and 10r have an abutting relationship to one another at zones 33 and 34. The set of panels 10k through 10r are matched by a mirror image set of panels to form the other half of the back insert 16b. The two halves of the insert 16b have an abutting relationship along the vertical zone 32. However, panels 10n, 10p, 10q and 10r are curved about a vertical axis and have a radius of curvature between ten and twelve inches. Panels 10k and 10m are curved about a vertical axis and have a curvature comparable to that of the front panels 10a through 10f. Because of the abutting zones, the amount of curvature of the panels is minimized and, in particular, the upper panels 10f, 10q and 10p need not be curved about a horizontal axis and thus complex curvatures are avoided.
A number of strip panels are employed to provide protection along the abutting zones 32, 33 and 34. All of these strip panels are two inches wide and thus only their lengths are indicated here. The vertically aligned strip panels 10t, 10u, 10w and 10x are respectively 6.5, 5.0, 3.25 and 3.0 inches long. The panels 10t and 10u have a one inch overlap whereas the rest of the relationships among these four strip panels are abutting relationships. The horizontal strip panel 10y has a center length of approximately 5.85 inches and the horizontal strip panel 10z has a center length of approximately 5.35 inches. These two panels 10y and 10z provide protective back-up along the zones 33 and 34 and are matched by mirror image panels on the other side of the insert 16b. The outer end of the panels 10y and 10z are tapered to conform to the taper defined by the panels 10p, 10q and 10r.
In a preferred embodiment, each titanium ply 12 is about 0.04 inches (0.10 cm) thick. This is effective to prevent a sharp instrument from penetrating. Each cloth ply 14 has a woven texture which provides a non-skid surface that serves to mechanically catch a blade tip or ice-pick tip. This prevents the tip from moving along the surface to a joint in the insert or to another area through which it could penetrate.
In a preferred embodiment, each felted ply is made of high density, high tensile, felt fabric having a thickness of about 0.090 inches (0.22 cm), a weight of about 10 ounces/sq. yard. The total thickness of a vest 38 formed from the inserts 16f and 16b is approximately three-eighth of an inch (0.95 cm) and has a weight, in a medium size, of about 6.1 pounds (2.76 kg) making the vest comfortably wearable for about eight hours.
In tests, it has been found that a vest employing these inserts 38 will resist eighty ft. lbs. of energy applied to ice picks and bowie knives. The vest also stopped the following threats at 0° obliquity.
______________________________________ BARREL LENGTH VELOC-BULLET TYPE (inches) ITY______________________________________.38 CAL. - 158 GR. 4" 775 F.P.S. S.W.C. LEAD.32 CAL. - AUTO 88 GR. 3" 680 F.P.S.12 Gauge - NO. 4 LEAD 18" -- SHOT______________________________________
Bullet resistance may be increased by the addition of aramid fabric layers on the body side.
In California, as much as one third of the correction officers are female. Accordingly, it is important that the body armor be designed to minimize the weight or pressure on a woman's breasts. The spacer element 40 serves to prevent undue pressure being exerted on the breasts of female users. The spacer 40 rests on the lower part of the wearer's rib cage. The armor, in turn, rests on the spacer 40 and thus the weight of the armor and the pressure that results is partially transferred to the lower part of the rib cage. Thus, the spacer 40 holds the front armor insert 16f outward and takes the pressure from that insert 16f.
The embodiment of this spacer 40 shown has a number of stepped plies 42. It could be a molded insert. In addition, the number of steps is a function of the breast size of the individual for whom it will be used. It has been found when the foam is stepped as shown, that the manner in which it responds to the weight of the body armor provides a fairly even distribution of weight over the rib cage and body of the wearer. The spacer 40 is enclosed within a woven nylon shell 44. Vertically running separable fasteners 46 such as Velcro strips are attached near the outward ends of the nylon cover and mate with corresponding fastener strips that are attached to the nylon shell 27 within which the body armor insert 16f is contained. The vertical fastener strips on the nylon cover of the body armor insert 16f are longer than the corresponding strips on the spacer 40 so that the spacer 40 can be positioned at a level desired by the individual wearing the item. The smallest ply 42a is positioned closest to the body and thus the fastener element is along the nylon cover which adjacent to the largest ply 42c.
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Multiple panels are assembled to provide front and back body armor inserts to be worn under regular clothing. Each panel consists of a ply of titanium metal bonded to a ply of aramid fiber woven cloth. The panels are arranged in overlapping and in abutting relationship but are not joined to one another except by way of overlying and underlying felted material plies. This provides an insert that is capable of some degree of flexing and adjustment on the body of the wearer. Back up strip panels protect the wearer along the abutting zones of the main panels.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Provisional Application Serial No. 60/328,619, filed Oct. 11, 2001 and entitled “A System for Detecting and Processing Signal Data Representing Repetitive Anatomical Functions.”
TECHNICAL FIELD
[0002] The present invention relates to medical systems and in particular to systems for monitoring physiological parameters.
BACKGROUND
[0003] Patient treatment often includes monitoring of various physiological parameters. Conventionally, such monitoring begins by attaching sensors to several locations on a patient's body. The sensors transmit signals to one or more devices, which in turn determine the values of subject parameters based on the signals. In this regard, a particular parameter value may be determined based on a signal received from one or more of the attached sensors.
[0004] Many methods have been employed to determine parameter values based on sensed physiological signals. According to some of these methods, a beat detector detects a beat that is present in a signal associated with a particular parameter. The detected beat is then used to determine a value of the particular parameter. For example, conventional algorithms may be used to compute a maximum pressure or peak of an electrocardiogram (EKG) from a detected beat. Values of other physiological parameters may be determined based on beats that are present in signals associated with the other parameters. These parameters include noninvasive blood pressure (NIBP), invasive blood pressure (IBP), and blood oxygen saturation level (SPO2).
[0005] Conventional beat detectors operate best when signals corresponding to associated physiological parameters are free of noise. These beat detectors therefore have difficulty in properly identifying beats in the presence of environmental noise and/or patient movement. As a result, any parameter values determined based on the identified beats suffer from inaccuracies.
[0006] Some systems attempt to address the foregoing by gating a beat associated with one parameter using a beat associated with another parameter, or by using a beat detected for one parameter to filter a beat associated with another parameter. The unidirectional processing of these systems does not lend itself to accuracy or flexibility. Moreover, the algorithms used for gating and filtering reflect a wide margin of error due to variations in physiology among patients. Consequently, these systems do not provide satisfactory accuracy and reliability.
[0007] A system is therefore desired to improve the determination of pulsation-based parameter values that satisfactorily addresses signal noise induced by motion or other environmental sources.
SUMMARY
[0008] To address at least the foregoing, some aspects of the present invention provide a system, method, apparatus, and means to determine a value of a physiological parameter. A system detects a pulsation associated with a physiological parameter. The system includes an input device for receiving a plurality of different signals, each of the plurality of different signals indicating a pulsation in respective different physiological parameters. A signal processor detects and accumulates information from the plurality of different signals. The accumulated information including values of relative delay between the pulsation in the respective different parameters. A timing processor determines a timing of the pulsation in at least one of the different parameters based at least on the accumulated information. The physiological parameters include parameters associated with at least two of, non-invasive blood pressure, invasive blood pressure, heart beat, blood oxygen saturation level, respiration rate, an ECG and temperature.
[0009] The present invention is not limited to the disclosed embodiments, however, as those of ordinary skill in the art can readily adapt the teachings of the present invention to create other embodiments and applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The exact nature of this invention, as well as its advantages, will become readily apparent from consideration of the following specification as illustrated in the accompanying drawings, wherein:
[0011] [0011]FIG. 1 is diagram illustrating patient monitoring according to some embodiments of the present invention;
[0012] [0012]FIG. 2 is a flow diagram illustrating process steps according to some embodiments of the present invention;
[0013] [0013]FIGS. 3 a through 3 f comprise diagrams illustrating map domains used in conjunction with some embodiments of the present invention; and
[0014] [0014]FIG. 4 is a block diagram of a single parameter beat detector according to some embodiments of the present invention.
DETAILED DESCRIPTION
[0015] The following description is provided to enable any person of ordinary skill in the art to make and use the invention and sets forth the best modes contemplated by the inventor for carrying out the invention. Various modifications, however, will remain readily apparent to those in the art.
[0016] [0016]FIG. 1 illustrates a patient monitoring system according to some embodiments of the present invention. The system illustrated in FIG. 1 may be located in any number of locations and may be used in any number of situations. Possible locations include a hospital, an office, and an ambulance, and possible situations include during an operation, during a checkup, and during a recovery period.
[0017] Attached to patient 1 are monitoring devices such as sensors for producing signals associated with physiological parameters. A physiological parameter according to some embodiments of the invention includes any identifiable characteristic of a patient's physiology. These parameters may include SPO2, NIBP, IBP, a heart beat associated parameter (e.g., HR—heart rate), respiration rate, and temperature.
[0018] According to some embodiments, the SPO2 parameter specifies a percentage of hemoglobin that is carrying oxygen. SPO2 values may be determined using pulse oximetry, in which blood (often located in the earlobe) is illuminated with two wavelengths of light and the SPO2 value is calculated based on the relative absorption of the two wavelengths. The NIBP and IBP parameters may specify blood pressures during heart contraction and during heart relaxation measured using a traditional blood pressure cuff (NIBP) or a cannula placed in an artery (IBP). Also in some embodiments, the HR parameter is a measure of heart beats over a time period, the respiration rate parameter is a measure of oxygen consumption over a period of time, and the temperature parameter reflects a core body temperature.
[0019] The signals produced by the sensors are received by monitoring devices such as monitors for determining a value of a physiological parameter therefrom. More specifically, SPO2 monitor 10 receives a signal associated with an SPO2 parameter from sensor 11 , EKG monitor 20 receives a signal associated with an EKG parameter from sensor 21 , NIBP monitor 30 receives a signal associated with an NIBP parameter from sensor 31 , and IBP monitor 40 receives a signal associated with an IBP parameter from sensor 41 . Each of sensors 11 , 21 , 31 and 41 is a sensor suitable to produce a signal representing an associated parameter. Accordingly, each monitor is used to determine a value of an associated parameter.
[0020] Monitors 10 , 20 , 30 and 40 may determine a value of a parameter based at least on a pulsation that is present in a signal associated with the parameter. In this regard, the pulsation is also considered to be associated with the signal. In some instances, the pulsation corresponds to the heart beat of patient 1 , but it may also correspond to the pulse rate of patient 1 . It should be noted that a pulsation according to the present invention may comprise any pulse represented in any signal. In some embodiments, a pulsation is associated with signals representing two or more physiological parameters and is used to determine the parameters.
[0021] It should be noted that, according to some embodiments, each monitor may receive signals from more than one sensor. Conversely, two or more monitors may receive signals from the same sensor. Each sensor may transmit a signal using any currently or hereafter-known system for transmitting data, including a RF, an infrared, and a fiber-optic system. Moreover, the signals may be transmitted over one or more of an IP network, an Ethernet network, a Bluetooth network, a cellular network, and any other suitable network.
[0022] Monitors 10 , 20 , 30 and 40 are in communication with communication bus 50 . Again, communication bus 50 may comprise any type of network, and communication therewith may proceed in accordance with any hardware and/or software protocol such as TCP/IP protocol. Also in communication with communication bus 50 is mapping server 60 . According to some embodiments, mapping server 60 receives signals from monitors 10 , 20 , 30 and 40 . As described above, each of the signals is associated with a respective parameter. Mapping server 60 determines values for two or more parameters based at least on a pulsation associated with each of the two or more parameters. Mapping server 60 also determines a temporal relationship between the two or more pulsations. The relationship describes a relative time delay between the two or more pulsations and is stored in association with the determined values. In one example, sensor 11 and sensor 41 produce signals including a pulsation corresponding to a heart beat of patient 1 . However, since sensor 41 is located farther from the heart than sensor 11 , the pulsation in the signal produced by sensor 41 is delayed with respect to the pulsation in the signal produced by sensor 11 . This and other processes will be described in more detail with respect to FIG. 2.
[0023] In this regard, FIG. 2 is a flow diagram of process steps 200 according to some embodiments of the present invention. Hardware and/or software for executing process steps 200 may be located in and/or executed by one or more of sensors 11 , 21 , 31 , and 41 , monitors 10 , 20 , 30 , and 40 , and mapping server 60 of FIG. 1.
[0024] Turning to the specific steps, signals representing a plurality of physiological parameters are received in step S 205 . In the presently-described embodiment, the signals are received by mapping server 60 from monitors 10 , 20 , 30 , and 40 . More than one received signal may represent a single parameter, and a received signal may represent more than one parameter. Accordingly, a signal that represents a parameter is a signal that encodes at least some information that is useful for determining a value of the parameter.
[0025] Next, in step S 210 , it is determined whether all the received signals are of good quality. This determination may be based on a threshold noise tolerance, which may be equal or different for each received signal. In some embodiments of step S 210 , it is determined whether enough of the received signals are of good quality to accurately determine values for each represented parameter. If the received signals are of good quality, values of associated parameters are determined in step S 215 .
[0026] As described above, the value of a parameter is determined based on at least a pulsation associated with the parameter. Accordingly, in step S 215 , pulsations respectively associated with two or more parameters are determined based on the received signals and a value of each of the two or more parameters is determined based on an associated pulsation. The determined parameter values may be presented to an operator by appropriate ones of monitors 10 , 20 , 30 and 40 or by mapping server 60 .
[0027] In one example of step S 215 , pulsations associated with the NIBP parameter, the IBP parameter, and the SPO2 parameter are determined based on signals received from sensor 30 , sensor 40 and sensor 10 , respectively. This determination may proceed using any currently or hereafter-known pulse detector, and results in, among other information, a time of occurrence corresponding to each pulsation. In this example, the pulsation associated with the HR parameter is determined to have occurred 2 milliseconds after the pulsation associated with the IBP parameter and 4 milliseconds after the pulsation associated with the NIBP parameter. Based on the respective pulsations, also determined in step S 215 are an NIBP value of 110/80, an IBP value of 120/90, and an SPO2 value of 97%.
[0028] Data points corresponding to the determined pulsations and values are added to a map or other data structure in step S 220 . The map specifies temporal relationships between pulsations associated with two or more physiological parameters for several combinations of parameter values. According to the above example, a combination of the three determined parameter values (i.e. 110/80, 120/90 and 77) is stored in a map along with an indication of a temporal relationship, or time delay, between the pulsations associated with two of the parameters (i.e. 2 ms, 4 ms or 6 ms).
[0029] [0029]FIGS. 3 a through 3 f illustrate map domains to which data points are added in step S 220 of FIG. 2 according to some embodiments of the present invention. As shown, each domain allows a temporal relationship between two pulsations associated with two physiological parameters to be expressed as a function of two or more physiological parameters. More specifically, FIG. 3 a illustrates a domain used to map a temporal relationship between an EKG pulsation and an SPO2 pulsation as a function of a combination of IBP and HR values. In another example, the FIG. 3 d domain allows mapping of a temporal relationship between an EKG pulsation and an NIBP pulsation as a function of IBP, HR and NIBP values. It should therefore be noted that a data point added to a map in step S 220 may associate values of any number of parameters with a temporal relationship between pulsations, and that the values may represent neither, one, or all of the parameters associated with the pulsations.
[0030] A map used in conjunction with some embodiments of the invention comprises a data structure that associates a plurality of sets of pulsation-based physiological parameter values with data representing a temporal relationship between a plurality of pulsations associated with respective ones of a plurality of parameters. In some embodiments, conventional curve-fitting algorithms are used to determine a map comprising one or more equations that approximate the data points determined in step S 215 . Such equations may present a temporal relationship in terms of a combination of parameter values. For example, an equation approximating a map according to FIG. 3 d may be in the form (T ekg −T nibp )=Fxn(HR, IBP, NIBP) These equations may be periodically revised based on the addition of data points in step S 220 .
[0031] After addition of a data point to an appropriate map in step S 220 , flow returns to step S 205 and continues as described above. Accordingly, data points continue to be added to maps in step S 220 as long as suitable good-quality signals are received in step S 205 .
[0032] Flow continues to step S 225 from step S 210 in a case that it is determined that one or more required signals are not of sufficient quality. In step S 225 , it is determined whether the received signals provide enough good-quality data to determine a pulsation associated with each parameter of interest. If so, flow proceeds to step S 230 , wherein pulsations respectively associated with each parameter of interest are determined.
[0033] In some embodiments, the pulsations are determined by first determining pulsations associated with one or more parameters based on good-quality signal data and using any currently or hereafter-known pulse detector. Each of these one or more parameters is then determined using the associated pulsation, data from the received signals, and currently or hereafter-known algorithms for determining the parameter. Since good-quality signal data is not available to determine pulsations of each parameter of interest, pulsations associated with one or more parameters of interest will not be determined. In order to determine one of these pulsations, a temporal relationship between the one pulsation and one or more of the determined pulsations is initially determined.
[0034] The temporal relationship may be determined based on the map created in step S 220 . In this regard, the map (function, data structure) is usable to determine a temporal relationship between a determined pulsation and an undetermined pulsation based on a combination of two or more determined parameter values. For example, pulsations and values associated with HR, NIBP and IBP were determined in step S 230 based on good-quality signals, but no pulsation was determined for SPO2. Accordingly, data points populating the map of FIG. 3 e are used in step S 230 to determine a temporal relationship between the SPO2 pulsation and the pulsation associated with NIBP based on the HR, NIBP and IBP parameter values. Particularly, a point on the map is identified for which the values of HR, NIBP and IBP are identical to the values determined in step S 230 . The temporal relationship (T spo2 −T nibp ) corresponding to the identified point is then determined. Since T nibp is known, T spo2 can be determined from the temporal relationship. T spo2 is then used as described above to determine a value of the SPO2 parameter.
[0035] It should be noted that the data points populating the map used in step S 230 may include those identified in step S 220 as well as those derived from different sources. In one example, pre-existing data records associated with patient 1 may include data points that can be used to populate maps such as those shown in FIGS. 3 a through 3 f . More specifically, data points may be appended to a patient record each time patient 1 is monitored, and the data points may be used to determine temporal relationships as described above. In some embodiments, the appended data points are those determined based on signals that exceed a predetermined quality threshold.
[0036] Of course, many other methods for determining a pulsation in step S 230 may be used in conjunction with the present invention. In some embodiments, several temporal relationships between known pulsations and an undetermined pulsation are determined based on different mappings as described above. The several temporal relationships may be averaged or otherwise weighted (perhaps based on relative signal qualities) to determine a single temporal relationship that is thereafter used to determine the pulsation.
[0037] After determination of the pulsations, any parameter values that have not yet been determined are determined based on the pulsations in step S 235 . This determination may proceed using algorithms as described above. All the parameters determined in steps S 230 and S 235 may then be presented to an operator, stored and/or used to trigger other processes. Flow returns to step S 205 from step S 235 .
[0038] If the determination of step S 225 is negative, multi-parameter sets are built in step S 240 using candidate pulsations. According to some embodiments of step S 225 , multi-parameter sets are built as follows. First, for each parameter to be determined, an associated pulsation is determined based on an associated received signal as described above. A value is determined for each parameter based on an associated pulsation, also as described above. The determined values comprise a multi-parameter set. It should be noted that since each received signal is of poor quality, the pulsations and parameters determined therefrom are unreliable.
[0039] Next, a second set of associated pulsations, one for each parameter, is determined based on the received signals. A second set of parameter values is then determined based on the second set of associated pulsations. Additional sets of parameter values may be similarly generated. Therefore, these embodiments result in multiple sets of parameter values, with each set corresponding to a set of pulsations determined based on noisy signals.
[0040] Next, in step S 245 , a rating is determined for each set of parameter values based on the mapping, which comprises temporal relationships determined for each of two or more combinations of parameter values. The rating for a set of parameter values may be determined by using currently or hereafter-known systems for determining how closely a data point matches a set of data points. In these embodiments, the rating reflects how closely a set of parameter values and associated pulsations conforms to the mapping (or mappings) created in step S 220 . A set of parameter values is then selected in step S 250 based at least on the determined ratings. For example, the set selected in step S 250 may be the set of values that is associated with a rating indicating that the set approximates the mapping more closely than any other set determined in step S 240 . Flow thereafter returns to step S 205 .
[0041] [0041]FIG. 4 is a block diagram of single parameter beat detector 400 that is used in some implementations of process steps 200 . In some embodiments, one detector such as beat detector 400 is associated with each parameter of interest. In this regard, each of monitors 10 , 20 , 30 and 40 may comprise one such detector. Therefore, in a case that beat detector 400 is associated with the SPO2 parameter, the parameter signal received by simple beat detector 410 and signal quality detector 420 is received from sensor 11 .
[0042] Simple beat detector 410 detects a pulsation in the received signal. Features are then extracted from the detected pulsation by feature extractor 430 to better determine the timing and shape of the pulsation. These features may include an amplitude in a rectified and filtered domain, timing information, and pulse shape data. It should be noted that the above functions of elements 410 and 430 may be performed using currently or hereafter-known beat detection techniques.
[0043] If the received signal is of good quality, the output of signal quality detector 420 is' low, thereby causing AND gate 450 to output a low signal. Pulse qualifier 440 is designed so that, upon receiving a low output from gate 450 , a qualified pulsation is determined and output in step S 215 based on the features extracted by feature extractor 430 . In this regard, the determination of a pulsation based on extracted features is known to those skilled in the art.
[0044] If a poor-quality signal is received, the output of signal quality detector is high and a Time Marker signal is input to pulse qualifier 440 . The Time Marker signal indicates an expected timing of the pulsation associated with the parameter of beat detector 400 . The expected timing is determined as described above with respect to step S 230 based on a map and on the determined pulsations and values associated with other parameters. Accordingly, the Time Marker signal may be received from any system having access to the map and capable of determining the pulsations and associated parameter values. In this regard, such a system may receive the features extracted by each instantiation of feature extractor 430 in order to calculate the parameter values.
[0045] Therefore, in the case of a poor-quality signal, pulse qualifier 440 also uses the Time Marker signal in addition to the extracted features in order to determine a qualified pulsation. In some embodiments, the qualified pulsation is biased toward an expected timing represented by the Time Marker signal. Next, in step S 235 , a parameter value is determined based on the qualified pulsation.
[0046] In a case that sufficient good-quality signals are not available to determine an expected timing of an associated pulsation from the map, a special Time Marker signal is transmitted to gate 450 . Upon detecting the special Time Marker signal, pulse qualifier 440 determines pulsations based on the extracted features and transmits the pulsations as candidate pulsations rather than as qualified pulsations. The candidate pulsations are used as described with respect to step S 240 to build multi-parameter sets of values.
[0047] Those in the art will appreciate that various adaptations and modifications of the above-described embodiments can be configured without departing from the scope and spirit of the invention. In some embodiments, functions attributed above to monitors 10 , 20 , 30 and 40 are performed by a single monitoring unit, such as the Siemens Infinity Patient Monitoring System. Some embodiments also include the functions of mapping server 60 into the single monitoring unit. Moreover, embodiments of the present invention may differ from the description of process steps 200 . Particularly, the particular arrangement of process steps 200 is not meant to imply a fixed order to the steps; embodiments of the present invention can be practiced in any order that is practicable.
[0048] Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
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Determination of a physiological parameter value includes reception of several signals, each representing a respective one of several physiological parameters and including a pulsation associated with the parameter. A system detects a pulsation associated with a physiological parameter. The system includes an input device for receiving a plurality of different signals, each of the plurality of different signals indicating a pulsation in respective different physiological parameters. A signal processor detects and accumulates information from the plurality of different signals. The accumulated information including values of relative delay between the pulsation in the respective different parameters. A timing processor determines a timing of the pulsation in at least one of the different parameters based at least on the accumulated information. The physiological parameters include parameters associated with at least two of, non-invasive blood pressure, invasive blood pressure, heart beat, blood oxygen saturation level, respiration rate, an ECG and temperature.
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RELATED UNITED STATES PATENT APPLICATIONS
Related United States Patent Applications
This application is related to co-pending U.S. patent application Ser. No. 13/291,582, entitled “Process For Preparing Fluorinated Block Copolyesters;” co-pending U.S. patent application Ser. No. 13/291,656, entitled “Polymer Blend Comprising Fluorinated Block Copolyester;” co-pending U.S. patent application Ser. No. 13/291,673, entitled “Shaped Articles Comprising a Fluorinated Block Copolyester;” co-pending U.S. patent application Ser. No. 12/873,423 entitled “Fluorovinylether Functionalized Aromatic Diesters And Derivatives Thereof, and Process for the Preparation Thereof,” filed on Sep. 1, 2010; and, co-pending U.S. patent application Ser. No. 12/873,428 entitled “Polyesters Comprising Fluorovinylether Functionalized Aromatic Moieties,” filed on Sep. 1, 2010.
FIELD OF THE INVENTION
The invention is directed to fluorinated block copolyesters comprising blocks of fluoroether functionalized aromatic polyester and blocks of unmodified polyester. The block copolymers incorporated into blends with unmodified aromatic polyester impart oil and soil resistance with high fluorine efficiency to shaped articles prepared from the blends.
BACKGROUND
Many polymers used in textile fiber applications, including apparel, bedding, and carpets and rugs, are known to exhibit susceptibility to staining. Polyesters and polyamides are known to exhibit staining from oily spills. The art discloses a number of surface treatment procedures and chemicals that have been employed over past decades to impart oil and soil repellency to polyester and polyamide fibers. Some of these treatments have been quite successful. However, all such treatments are subject to degradation from repeated wear—they tend to be gradually wiped off the surface in ordinary use. As a result, the well-known surface treatments used in the art tend to lose effectiveness over time, and require restoration. Restoration is a responsibility that devolves upon the consumer. Failure to regularly restore the surface treatment leads to premature deterioration of the appearance of the textile article to which it had been applied.
It is clear in the art that there is a need to provide oil and soil repellency of greater durability to polyester and polyamide textile goods.
Generally, oily substances cause staining in polyesters and polyamides because the oily substance wets the surface, and then diffuses into the interstices of the fibrous material. Soil repellency technologies have typically been directed to reducing the surface energy of the fibers to reduce the tendency of oils to wet the surface. It is well-known in the art that fluorinated chemicals are highly effective at reducing the surface energy of polyester and polyamide textile goods.
Fluorinated chemicals are also expensive, so it is highly desirable that as high a percentage as possible of the available fluorine atoms be caused to reside on the fiber surface, rather than within the body of the fiber where it does no good for soil repellency. In addition, the lower the concentration of additives in a polymer, the higher the property retention of the polymer itself. The higher the percentage of the fluorine atoms that reside on the surface of the fiber, the higher the so-called fluorine efficiency. A high fluorine efficiency is highly desirable.
Yokozawa et al. (Prog. Polym. Sci. 2007, 32, 147) disclose a so-called chain growth polycondensation process for the manufacturing of condensation polymers with defined molecular weights, molecular weight distributions and selective compositions.
WO2011/028778 discloses poly(alkylene arylate) copolymers comprising fluoroether functionalized alkylene arylate repeat units. Soil and water resistant fibers and fabrics prepared therefrom are disclosed.
Several block copolyesters or copolyether esters are in commercial use. Devaux et al., J. Poly Sci, Pol. Phys., 20, 1875pp (1982); and, Devaux, Chapt. 3, Transreactions in Condensation Polymers , Fakirov, ed., John Wiley & Sons, DOI: 10.1002/9783527613847, Chapter 3.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a block copolymer having a blockiness index, B, in the range of 0.25 to 1.0, comprising a first block comprising a plurality of non-fluorinated alkylene arylate repeat units adjacent to one another; and a second block comprising a plurality of fluoroether functionalized alkylene arylate repeat units adjacent to one another; said non-fluorinated alkylene arylate repeat unit represented by Structure I
wherein each R is independently H or C 1 -C 10 alkyl, and R 3 is C 2 -C 4 alkylene which can be branched or unbranched;
and, said fluoroether functionalized repeat units are represented by Structure II,
wherein Ar represents a benzene or naphthalene radical; each R is independently H, C 1 -C 10 alkyl, C 5 -C 15 aryl, C 6 -C 20 arylalkyl; OH, or a radical represented by the Structure (III)
with the proviso that only one R can be OH or the radical represented by the Structure (III);
R 1 is a C 2 -C 4 alkylene radical which can be branched or unbranched, X is O or CF 2 ; Z is H, Cl, or Br; a=0 or 1; and, Q represents the Structure (IIa)
wherein q=0-10;
Y is O or CF 2 ;
Rf 1 is (CF 2 ) n , wherein n is 0-10;
and,
Rf 2 is (CF 2 ) p , wherein p is 0-10, with the proviso that when p is 0, Y is CF 2 .
In another aspect, the invention provides a process comprising combining in the presence of a catalyst a non-fluorinated poly(alkylene arylate) first homopolymer and a fluoroether functionalized poly(alkylene arylate) second homopolymer to form a reaction mixture; heating said reaction mixture under vacuum to a temperature above the melting temperatures of each said homopolymer to prepare a liquified reaction mixture; and, agitating the liquified reaction mixture until the desired molecular weight is achieved.
In another aspect, the invention provides a polymer blend comprising a poly(alkylene arylate) and 0.1 to 10 weight percent based upon the total weight of the blend of a block copolymer having a blockiness index, B, in the range of 0.25 to 1.0, comprising a first block comprising a plurality of non-fluorinated alkylene arylate repeat units adjacent to one another; and a second block comprising a plurality of fluoroether functionalized alkylene arylate repeat units adjacent to one another; said non-fluorinated alkylene arylate repeat unit represented by Structure I
wherein each R is independently H or C 1 -C 10 alkyl, and R 3 is C 2 -C 4 alkylene which can be branched or unbranched;
and, said fluoroether functionalized repeat units are represented by Structure II,
wherein, Ar represents a benzene or naphthalene radical; each R is independently H, C 1 -C 10 alkyl, C 5 -C 15 aryl, C 6 -C 20 arylalkyl; OH, or a radical represented by the Structure (III)
with the proviso that only one R can be OH or the radical represented by the Structure (III);
R 1 is a C 2 -C 4 alkylene radical which can be branched or unbranched, X is O or CF 2 ; Z is H, Cl, or Br; a=0 or 1; and,
Q represents the Structure (IIa)
wherein q=0-10;
Y is O or CF 2 ;
Rf 1 is (CF 2 ) n , wherein n is 0-10;
and,
Rf 2 is (CF 2 ) p , wherein p is 0-10, with the proviso that when p is 0, Y is CF 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B depict the NMR peaks from the ratios of which the blockiness index, B, of a copolymer is determined.
FIG. 2 depicts the molecular weight distributions of the two low molecular weight homopolymers from which a block copolymer according to the invention is prepared. The molecular weight distribution of the block copolymer is also shown.
FIG. 3 is a schematic depiction of the fiber spinning apparatus employed in Example 8.
DETAILED DESCRIPTION
When a range of values is provided herein, it is intended to encompass the end-points of the range unless specifically stated otherwise. Numerical values used herein have the precision of the number of significant figures provided, following the standard protocol in chemistry for significant figures as outlined in ASTM E29-08 Section 6. For example, the number 40 encompasses a range from 35.0 to 44.9, whereas the number 40.0 encompasses a range from 39.50 to 40.49.
Molecular weight of the polyester polymers disclosed herein can be determined by any of a variety of methods. One such method commonly employed in the art of polyester polymers is the measurement of so-called intrinsic viscosity. The intrinsic viscosity of a polymer is determined by extrapolation of the measured solution viscosity of the polymer to zero concentration of polymer. The intrinsic viscosity so determined can then be related to the weight-average molecular weight (M w ) of the polymer by the Mark-Houwink equation, as described in Polymer Chemistry , Charles L. Carraher Jr., 5th edition, Marcel-Dekker (2000)
Another method for determining molecular weight is by so-called size-exclusion chromatography (SEC). A suitable method for performing SEC on the polymers is provided infra. SEC has the advantage of defining the entire molecular weight distribution, whereas intrinsic viscosity defines a single point on that distribution.
The parameters n, p, and q as employed herein are each independently integers in the range of 1-10.
As used herein, the term “copolymer” refers to a polymer comprising two or more chemically distinct repeat units in the polymer chain, including dipolymers, terpolymers, tetrapolymers and the like. The term “homopolymer” refers to a polymer wherein the repeat units in the polymer chain are chemically indistinguishable from one another (with the possible exception of the end groups). For the sake of brevity and clarity, the present disclosure is directed to copolymers comprising two chemically distinct repeat units. However, the same description can be readily extended to polymers having more than two chemically distinct repeat units. The copolymers disclosed herein preferably consist essentially of two chemically distinct repeat units.
In a copolymer comprising a first repeat unit and a second repeat unit, the term “block” in the phrase “block copolymer” refers to a sub-section of the copolymer chain in which a plurality of first repeat units are adjacent to one another rather than adjacent to second repeat units. In a copolymer formed by completely random combination of the two repeat units, there will result a certain number of blocks, of certain lengths of each repeat unit. The specific number of blocks and their length will depend upon the molar ratios of the repeat units, the relative reactivity of the repeat units, and other factors. A block copolymer is one in which the number and size of the blocks exceeds by a statistically significant amount that determined for a random copolymer of similar overall composition.
The blockiness index, B, is defined by Devaux, op. cit., as
B = F 12 2 ∑ i = 1 2 F i
wherein F 12 represents the total mole fraction of diads of first and second repeat units, in either sequence, and F i represents the mole fraction of repeat units of type “i” and the sum is taken over the two types of repeat units. For a 50/50 mol % composition of two polymer components B takes a value of 0 for a perfect block copolymer since F 12 =F 21 ≈0, and a value of 1 for a random copolymer since F 12 =F 21 ≈0.25, in both these cases F 1 =F 2 ≈0.5.
F 12 , F 21 , F 11 , and F 22 are the molar fractions of dyad repeat units in the polymer structure. The different dyads present in the copolymers:
The designation “G” represents the NMR peak of the two OCH 2 carbons when two trimethylene terephthalate moieties are adjacent to one another; this dyad is designated TT; its mole fraction is F 11 . The designation “D” represents the NMR peak of the two OCH 2 carbons when two 3-GF 16 -iso (or two 3-GF 10 -iso) moieties are adjacent to one another; this dyad is denoted FF; its mole fraction F 22 . The designations “E” and “F” represent the two NMR peaks of the two different OCH 2 groups in the dyad which contains both a 3-GF 16 -iso (or 3-GF 10 -iso) moiety and a trimethylene terephthalate moiety. There are two statistically possible arrangements of this dyad, which are equivalent by NMR, designated FT and TF, with mole fractions F 12 and F 21 . The relative amount of the TT dyad is determined by the area of peak G/2, of the FF dyad by the area of D/2, and of the sum FT and TF dyads by the area of (E+F)/2. These dyad amounts can be normalized to 100% to give the mole fraction of each type of dyad. Each of the dyad mole fractions is thus determined as follows:
F i = ∫ X i ∑ j = 1 - 4 ∫ X j
In a random copolymer the statistical ratio of the dyad is 1:2:1 for TT:TF+FT:FF. In this case the areas of peaks D, E, F, G will be 1:1:1:1.
A representative NMR is shown in FIG. 1 . A random copolymer and a blocky copolymer were prepared to have identical composition. A specimen of each was dissolved in deuterated trichloroethylene (TCE-d2), and the 13 C NMR spectrum determined on a 700 MHz NMR. In the range of 63-62 ppm, four peaks were observed, designated respectively, E, D, G, F. The top set of peaks corresponded to the random copolymer. The bottom set of peaks corresponded to the blocky copolymer.
Referring again to FIG. 1 , it is clear that in a random copolymer, the relative mole fraction of any one dyad is as probable as that of another. However, in the block copolymer, the mole fractions corresponding to the E and F dyads (F 12 and F 21 ) were reduced in favor of higher mole fractions corresponding to the D and G dyads (F 11 and F 22 ).
Another way to characterize block copolymers is to compare the molecular weight distributions of the starting oligomeric or low molecular weight homopolymers with that of the final copolymer. FIG. 2 depicts results obtained from size exclusion chromatography employing the method described infra. In FIG. 2 , curves 1 and 2 depict molecular weight distribution of fluorinated and non-fluorinated homopolymers having a M n of ca. 9,000 D. Curve 3 depicts the molecular weight distribution of the copolymer formed therefrom according to the process. The M n of the copolymer was ca. 60,000 D. All three distributions have a polydispersity (M w /M n ) of ca. 2.0—the typical characteristic of a single condensation polymer population. Thus, the copolymer indicates that the two low molecular weight homopolymers fully reacted to form a single higher molecular weight polymer population, and that the copolymer is a multi-block copolymer.
A block copolymer also presents characteristic thermodynamic properties. Because of the blocky structure along the polymer chain, the block copolymer retains some of the features of the separate homopolymers that constitute the blocks. The block copolymer has two glass transition temperatures that are close to those of the separate homopolymeric components, and a melting point that corresponds to that of the non-fluorinated poly(alkylene arylate) homopolymer component. In contrast, a random copolymer of the same overall composition exhibits only one glass transition temperature that corresponds to neither of those of the separate components, and no melting point because the randomized presence of the fluorinated moiety along the polymer chain acts to disrupt the crystallization of the non-fluorinated component. The fluorinated homopolymer is fully amorphous, and doesn't exhibit a melting point.
In one aspect, the present invention provides a copolymer having a blockiness index, B, in the range of 0.25 to 1.0, comprising a first block comprising a plurality of non-fluorinated alkylene arylate repeat units adjacent to one another; and a second block comprising a plurality of fluoroether functionalized alkylene arylate repeat units adjacent to one another; said non-fluorinated alkylene arylate repeat unit represented by Structure I
wherein each R is independently H or C 1 -C 10 alkyl, and R 3 is C 2 -C 4 alkylene which can be branched or unbranched;
and, said fluoroether functionalized repeat units are represented by Structure II,
wherein, Ar represents a benzene or naphthalene radical; each R is independently H, C 1 -C 10 alkyl, C 5 -C 15 aryl, C 6 -C 20 arylalkyl; OH, or a radical represented by the Structure (III)
with the proviso that only one R can be OH or the radical represented by the Structure (III);
R 1 is a C 2 -C 4 alkylene radical which can be branched or unbranched, X is P or CF 2 ; Z is H, Cl, or Br; a=0 or 1; and, Q represents the Structure (IIa)
wherein q=0-10; Y is O or CF 2 ; Rf 1 is (CF 2 ) n , wherein n is 0-10; and, Rf 2 is (CF 2 ) p , wherein p is 0-10, with the proviso that when p is 0, Y is CF 2 .
As can be noted in the formulas above that show substituents attached to aromatic rings “Ar”, the substituents can be attached to the aromatic rings at any point, thus making it possible to have ortho-, meta- and para-substituents as defined above.
There is no particular limitation on the relative amount of the fluoroether functionalized repeat units and non-fluorinated repeat units. The desired amounts will be determined by considerations peculiar to the intended use. In one embodiment of the copolymer, the mole ratio of non-fluorinated repeat units to fluoroether functionalized repeat units is in the range of 9 to 0.25. In a further embodiment, the mole ratio is in the range of 1.5 to 0.67.
In one embodiment of the polymer, each R is H.
In one embodiment of the fluoroether functionalized alkylene arylate repeat unit, one R is represented by the Structure (II) and the remaining two Rs are each H.
In one embodiment, R 1 is an ethylene radical.
In one embodiment, R 1 is a trimethylene radical, which can be branched.
In one embodiment, R 1 is a tetramethylene radical, which can be branched.
In one embodiment, X is O. In an alternative embodiment, X is CF 2 .
In one embodiment, Y is O. In an alternative embodiment, Y is CF 2 .
In one embodiment, Rf 1 is CF 2 .
In one embodiment, Rf 2 is CF 2 .
In one embodiment, Rf 2 is a bond (that is, p=0), and Y is CF 2 .
In one embodiment, a=0.
In one embodiment, a=1, q=0, and n=0.
In one embodiment of the fluoroether functionalized alkylene arylate repeat unit, Ar is a benzene radical, a=1, each R is H, Z is H, R 1 is trimethylene, X is O, Y is O, Rf 1 is CF 2 , and Rf 2 is perfluoropropenyl, and q=1.
In one embodiment the specific repeat unit represented by Structure (I) is represented by the Structure (IVa)
wherein R 1 , Z,X,Q, and a are as stated supra.
In an alternative embodiment the specific repeat unit represented by Structure (I) is represented by the Structure (IVb)
wherein R 1 , Z,X,Q, and a are as stated supra.
In one embodiment the non-fluorinated alkylene arylate repeat unit comprising arylate repeat unit is represented by the Structure (V),
wherein R 3 is C 2 -C 4 alkylene which can be branched or unbranched. In one embodiment, R 3 is trimethylene. In one embodiment, the repeat unit represented by Structure (V) is a C 2 -C 4 alkylene terephthalate radical, especially a trimethylene terephthalate radical. In an alternative embodiment, the repeat unit represented by Structure (V) is a C 2 -C 4 alkylene isophthalate radical, especially a trimethylene terephthalate radical.
The molecular weight of the final copolymer varies depending on the overall condensation time. Typically a longer overall reaction time leads to higher overall molecular weight assuming adequate vacuum and stirring conditions can be maintained. In general, molecular weight number averages (M n ) between 20,000 Da (Intrinsic viscosity I.V.<0.4 dL/g) to 100,000 Da (I.V.=0.73 dL/g) was reached.
In one embodiment of the copolymer, the mole ratio of non-fluorinated repeat units to fluoroether functionalized repeat units is in the range of 9 to 0.25. In a further embodiment, the mole ratio is in the range of 1.5 to 0.67.
In another aspect, the invention provides a process comprising combining in the presence of a catalyst a non-fluorinated poly(alkylene arylate) first homopolymer and a fluoroether functionalized poly(alkylene arylate) second homopolymer to form a reaction mixture; heating said reaction mixture under vacuum to a temperature above the melting temperatures of each said homopolymer to prepare a molten reaction mixture; and, agitating the molten reaction mixture until the desired molecular weight is achieved.
In one embodiment, the fluoroether-functionalized poly(alkylene arylate) is an oligomer having a number average molecular weight in the range of 5,000 to 15,000 Da.
In one embodiment, both the non-fluorinated poly(alkylene arylate)homopolymer and the fluoroether-functionalized poly(alkylene arylate)homopolymer are oligomers having a number average molecular weight in the range of 5,000 to 15,000 D.
It has now been found that little transesterification occurs in the melt between the fluoroether functionalized homopolymer and the non-fluorinated homopolymer. Condensation reactions occur at end groups of the melt-mixed polymers in the presence of a suitable catalyst. The internal structure of the homopolymer chains remains substantially intact. The product of the reaction is the block copolymer.
The number and size of the blocks in the polymer chain will depend upon the molecular weight of each of the starting homopolymers. High molecular weight homopolymer starting materials will lead to copolymers having a relatively small number of relatively large blocks, and reaction rate is relatively slow. The molecular weight of the resulting polymer could be undesirably high for many applications. Low molecular weight homopolymer starting materials result in copolymers with more but relatively shorter blocks. The resulting copolymers may exhibit undesirably low molecular weight. The molecular weight of the copolymer can be increased by increasing the reaction time, but longer reaction time also results in more transesterification and greater randomization.
Any non-fluorinated poly(alkylene arylate)homopolymer such as is known in the art is suitable for use as the non-fluorinated poly(alkylene arylate)homopolymer in the processes disclosed herein. Suitable non-fluorinated poy(alkylene arylate)homopolymers include, but are not limited to, poly(ethylene terephthalate)homopolymer, poly(trimethylene terephthalate)homopolymer, and poly(tetramethylene terephthalate)homopolymer. Suitable non-fluorinated poly(alkylene arylate)homopolymers have a molecular weight, as measured by intrinsic viscosity (I.V.) in the range of 0.1-1.1 dL/g. with 0.3-0.4 dL/g preferred. Suitable non-fluorinated poly(alkylene arylates) can be purchased from commercial sources, or produced in a laboratory setup to reach molecular weights outside the commercial range. An aromatic polyester homopolymer is prepared by mixing dimethylterepthalate or terephthalic acid with an excess of C 2 -C 4 alkylene glycol or a mixture thereof, branched or unbranched, and a catalyst to form a reaction mixture. The reaction can be conducted in the melt, preferably within the temperature range of 180 to 240° C., to initially condense either methanol or water, after which the mixture can be further heated, preferably to a temperature within the range of 230 to 300° C., and evacuated, to remove the excess C 2 -C 4 glycol and thereby form a homopolymer
Suitable catalysts include but are not limited to titanium (IV) butoxide, titanium (IV) isopropoxide, antimony trioxide, antimony triglycolate, sodium acetate, manganese acetate, and dibutyl tin oxide. The selection of catalysts is based on the degree of reactivity associated with the selected glycol. For example, it is known that 1,3-propanediol is considerably less reactive than is 1,2-ethanediol. Titanium butoxide and dibutyl tin oxide—both considered “hot” catalysts—have been found to be suitable for process when 1,3-propanediol is employed, but are considered over-active for the process when 1,2-ethanediol.
The reaction can be carried out in the melt. The resulting polymer can be separated by vacuum distillation to remove the excess of C 2 -C 4 glycol.
Preparation of a suitable fluoroether functionalized poly(alkylene arylate) homopolymer is described in WO2011/028778. A fluoroether functionalized aromatic diester or diacid is combined with an excess of C 2 -C 4 alkylene glycol or a mixture thereof, branched or unbranched, and a catalyst to form a reaction mixture. The reaction can be conducted in the melt, preferably within the temperature range of 180 to 240° C., to initially condense either methanol or water, after which the mixture can be further heated, preferably to a temperature within the range of 210 to 300° C., and evacuated, to remove the excess C 2 -C 4 glycol and thereby form a homopolymer comprising repeat units having the Structure (II), wherein the fluoroether functionalized aromatic diester or diacid is represented by the Structure (V),
wherein, Ar represents a benzene or naphthalene radical; each R is independently H, C 1 -C 10 alkyl, C 5 -C 15 aryl, C 6 -C 20 arylalkyl; OH, or a radical represented by the Structure (III)
with the proviso that only one R can be OH or the radical represented by the Structure (III); R 2 is H or C 1 -C 10 alkyl; X is O or CF 2 ; Z is H, Cl, or Br; a=0 or 1;
and, Q represents the Structure (IIa)
wherein q=0-10; Y is O or CF 2 ; Rf 1 is (CF 2 ) n , wherein n is 0-10; and, Rf 2 is (CF 2 ) p , wherein p is 0-10, with the proviso that when p is 0, Y is CF 2 .
In some embodiments, the reaction is carried out at about the reflux temperature of the reaction mixture.
In one embodiment of the process, one R is OH.
In one embodiment of the process, each R is H.
In one embodiment of the process, one R is OH and the remaining two Rs are each H.
In one embodiment of the process, one R is represented by the Structure (II) and the remaining two Rs are each H.
In one embodiment of the process, R 2 is H.
In one embodiment of the process, R 2 is methyl.
In one embodiment of the process, X is O. In an alternative embodiment, X is CF 2 .
In one embodiment of the process, Y is O. In an alternative embodiment, Y is CF 2 .
In one embodiment of the process, Rf 1 is CF 2 .
In one embodiment of the process, Rf 2 is CF 2 .
In one embodiment of the process, Rf 2 is a bond (that is, p=0), and Y is CF 2 .
In one embodiment, a=0.
In one embodiment, a=1, q=0, and n=0.
In one embodiment of the process, each R is H, Z is Cl, R2 is methyl, X is O, Y is O, Rf1 is CF2, and Rf2 is perfluoropropenyl, and q=1.
Suitable alkylene glycols include but are not limited to 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, and mixtures thereof. In one embodiment, the alkylene glycol is 1,3-propanediol.
Suitable catalysts include but are not limited to titanium (IV) butoxide, titanium (IV) isopropoxide, antimony trioxide, antimony triglycolate, sodium acetate, manganese acetate, and dibutyl tin oxide. The selection of catalysts is based on the degree of reactivity associated with the selected glycol. For example, it is known that 1,3-propanediol is considerably less reactive than is 1,2-ethanediol. Titanium butoxide and dibutyl tin oxide—both considered “hot” catalysts—have been found to be suitable for process when 1,3-propanediol is employed, but are considered over-active for the process when 1,2-ethanediol.
The reaction can be carried out in the melt. The thus resulting polymer can be separated by vacuum distillation to remove the excess of C 2 -C 4 glycol.
Suitable fluoroether functionalized aromatic diesters can be prepared by forming a reaction mixture comprising a hydroxy aromatic diester in the presence of a solvent and a catalyst with a perfluoro vinyl compound represented by the Structure (VI)
wherein X is O or CF 2 , a=0 or 1; and, Q represents the Structure (IIa)
wherein q=0-10; Y is O or CF 2 ; Rf1 is (CF 2 ) n , wherein n is 0-10; Rf 2 is (CF 2 ) p , wherein p is 0-10, with the proviso that when p is 0, Y is CF 2 ;
under agitation at a temperature between about −70° C. and the reflux temperature of the reaction mixture. The reaction mixture is cooled following reaction.
When a halogenated solvent is employed, the group indicated as “Z” in the resulting fluoroether aromatic diester represented by Structure (V) is the corresponding halogen. Suitable halogenated solvents include but are not limited to tetrachloromethane, tetrabromomethane, hexachloroethane and hexabromoethane. If the solvent is non-halogenated Z is H. Suitable non-halogenated solvents include but are not limited to tetrahydrofuran (THF), dioxane, and dimethylformamide (DMF).
The reaction is catalyzed by a base. A variety of basic catalysts can be used, i.e., any catalyst that is capable of deprotonating phenol. That is, a suitable catalyst is any catalyst having a pKa greater than that of phenol (9.95, using water at 25° C. as reference). Suitable catalysts include, but are not limited to, sodium methoxide, calcium hydride, sodium metal, potassium methoxide, potassium t-butoxide, potassium carbonate or sodium carbonate. Preferred are potassium t-butoxide, potassium carbonate, or sodium carbonate.
Reaction can be terminated at any desirable point by the addition of acid (such as, but not limited to, 10% HCl). Alternatively, when using solid catalysts, such as the carbonate catalysts, the reaction mixture can be filtered to remove the catalyst, thereby terminating the reaction.
Suitable hydroxy aromatic diesters include, but are not limited to, 1,4-dimethyl-2-hydroxy terephthalate, 1,4-diethyl-2-5-dihydroxy terephthalate, 1,3-dimethyl 4-hydroxyisophthalate, 1,3-dimethyl-5-hydroxy isophthalate, 1,3-dimethyl 2-hydroxyisophthalate, 1,3-dimethyl 2,5-dihydroxyisophthalate, 1,3-dimethyl 2,4-dihydroxyisophthalate, dimethyl 3-hydroxyphthalate, dimethyl 4-hydroxyphthalate, dimethyl 3,4-dihydroxyphthalate, dimethyl 4,5-dihydroxyphthalate, dimethyl 3,6-dihydroxyphthalate, dimethyl 4,8-dihydroxynaphthalene-1,5-dicarboxylate, dimethyl 3,7-dihydroxynaphthalene-1,5-dicarboxylate, dimethyl 2,6-dihydroxynaphthalene-1,5-dicarboxylate, or mixtures thereof.
Suitable perfluorovinyl compounds include, but are not limited to, 1,1,1,2,2,3,3-heptafluoro-3-(1,1,1,2,3,3-hexafluoro-3-(1,2,2-trifluorovinyloxy)propan-2-yloxy)propane, heptafluoropropyltrifluorovinylether, perfluoropent-1-ene, perfluorohex-1-ene, perfluorohept-1-ene, perfluorooct-1-ene, perfluoronon-1-ene, perfluorodec-1-ene, and mixtures thereof.
To prepare a suitable fluoroether functionalized aromatic diester a suitable hydroxy aromatic diester and a suitable perfluovinyl compound are combined in the presence of a suitable solvent and a suitable catalyst until the reaction has achieved the desired degree of conversion. The reaction can be continued until no further product is produced over some preselected time scale. The required reaction time to achieve the desired degree of conversion depends upon the reaction temperature, the chemical reactivity of the specific reaction mixture components, and the degree of mixing applied to the reaction mixture. Progress of the reaction can be monitored using any one of a variety of established analytical methods, including, but not limited to, nuclear magnetic resonance spectroscopy, thin layer chromatography, and gas chromatography.
When the desired level of conversion has been achieved, the reaction mixture is quenched, as described supra. The thus quenched reaction mixture can be concentrated under vacuum, and rinsed with a solvent. Under some circumstances, a plurality of compounds encompassed by the Structure (V) can be made in a single reaction mixture. In such cases, separation of the products thus produced can be effected by any method known to the skilled artisan such as, but not limited to, distillation or column chromatography.
If it is desired to employ the corresponding diacid instead of the diester, the thus produced fluoroether functionalized aromatic diester can be contacted with an aqueous base, preferably a strong base such as KOH or NaOH, at a gentle reflux, followed by cooling to room temperature, followed by acidifying the mixture, preferably with a strong acid, such as HCl or H 2 SO 4 , until the pH is between 0 and 2. Preferably pH is 1. The acidification thus performed causes the precipitation of the fluoroether functionalized aromatic diacid. The thus precipitated diacid can then be isolated via filtration and recrystallization from suitable solvents (e.g., redissolved in a solvent such as ethyl acetate, and then recrystallized). The progress of the reaction can be followed by any convenient method, including but not limited to thin layer chromatography, gas chromatography and NMR.
Once the fluoroether functionalized aromatic compound has been thus prepared, it is suitable for use in preparation of the fluoroether functionalized homopolymer for use in the processes disclosed herein, among other potential uses.
In another aspect, the invention provides a polymer blend comprising a poly(alkylene arylate) and 0.1 to 10 weight percent, preferably 0.5-5%, based upon the total weight of the blend of a block copolymer having a blockiness index, B, in the range of 0.25 to 1.0, comprising a first block comprising a plurality of non-fluorinated alkylene arylate repeat units adjacent to one another; and a second block comprising a plurality of fluoroether functionalized alkylene arylate repeat units adjacent to one another; said non-fluorinated alkylene arylate repeat unit represented by Structure I
wherein each R is independently H or C 1 -C 10 alkyl, and R 3 is C 2 -C 4 alkylene which can be branched or unbranched;
and, said fluoroether functionalized repeat units are represented by Structure II,
wherein, Ar represents a benzene or naphthalene radical; each R is independently H, C 1 -C 10 alkyl, C 5 -C 15 aryl, C 6 -C 20 arylalkyl; OH, or a radical represented by the Structure (III)
with the proviso that only one R can be OH or the radical represented by the Structure (III); R 1 is a C 2 -C 4 alkylene radical which can be branched or unbranched, X is O or CF 2 ; Z is H, Cl, or Br; a=0 or 1;
and,
Q represents the Structure (IIa)
wherein q=0-10; Y is O or CF 2 ; Rf 1 is (CF 2 ) n , wherein n is 0-10; and,
Rf 2 is (CF 2 ) p , wherein p is 0-10, with the proviso that when p is 0, Y is CF 2 .
At concentrations of the block copolymer in the blend less than 0.1 weight-% (wt-%) no significant beneficial effect is achieved. At concentrations of the block copolymer in the blend greater than 10 wt-%, the desirable properties of the poly(alkylene arylate) are suppressed, and poor fluorine efficiency results.
In one embodiment, the poly(alkylene arylate) is a poly(alkylene terephthalate). Suitable poly(alkylene terephthalates) include, but are not limited to, poly(ethylene terephthalate), poly(trimethylene terephthalate), poly(tetramethylene terephthalate), or poly(ethylene napthalate). In one embodiment, the poly(alkylene terephthalate) is poly(trimethylene terephthalate)
In one embodiment, poly(trimethylene terephthalate) has an IV of 0.85 to 1.1 dL/g. The poly(trimethylene terephthalate) (PTT) having an IV of 0.85 to 1.1 dL/g encompasses homopolymers and copolymers containing at least 70 mole trimethylene terephthalate repeat units. The preferred PTT contains at least 85 mole %, more preferably at least 90 mole %, even more preferably at least 95 or at least 98 mole %, and most preferably about 100 mole %, trimethylene terephthalate repeat units.
The poly(trimethylene terephthalate) can contain minor amounts of other comonomers, and such comonomers are usually selected so that they do not have a significant adverse effect on properties. Such other comonomers include 5-sodium-sulfoisophthalate, for example, at a level in the range of about 0.2 to 5 mole %. Very small amounts of trifunctional comonomers, for example trimellitic acid, can be incorporated for viscosity control.
In one embodiment of the copolymer, the mole ratio of non-fluorinated repeat units to fluoroether functionalized repeat units is in the range of 9 to 0.25. In a further embodiment, the mole ratio is in the range of 1.5 to 0.67.
The blend hereof is prepared in a high shear melt mixing process. Any high shear melt mixing process normally employed in the art to prepare polymer blends is suitable This includes use of twin-screw extruders, Farrel continuous mixers, Brabender and Banbury batch mixers, and the like. In a suitable process, the components are weight loss fed to the feed zone of a twin-screw extruder in which they are melted and aggressively mixed, followed by extrusion into strands that, after quenching, are cut into blend pellets suitable for use in a wide variety of polymer processes.
Alternatively, the melt blend can be fed directly to a metering pump and thence to a spin head for direct melt spinning into melt blend fibers.
The blend is suitable also for the production of extruded films and sheets; and of molded parts such as by compression or injection molding.
The invention is further described and enabled in the following specific embodiments, but is not limited in scope thereto.
EXAMPLES
Materials
Purchased From Aldrich Chemical Company, and Used as Received, Were
dimethyl terephthalate (DMT)
dimethyl isophthalate (DMI)
titanium(IV) isopropoxide
ethylene glycol
1,4-butanediol
tetrahydrofuran (THF)
dimethyl 5-hydroxyisophthalate
potassium carbonate
Obtained From the DuPont Company and Used as Received, Unless Otherwise Noted.
Bio-based 1,3-propanediol (Bio-PDO™)
1,1,1,2,2,3,3-heptafluoro-3-(1,2,2-trifluorovinyloxy)propane (PPVE) Sorona® Poly(trimethylene terephthalate) (PTT), bright 1.02 IV
Purchased From SynQuest Labs, and Used as Received
1,1,1,2,2,3,3-heptafluoro-3-(1,1,1,2,3,3-hexafluoro-3-(1,2,2-trifluorovinyloxy)propan-2-yloxy)propane (PPPVE)
Testing Methods
Surface Analysis
Surface contact angles of hexadecane on polymer film were recorded on a. Ramé-Hart Model 100-25-A goniometer (Ramé-Hart Instrument Co) with an integrated DROPimage Advanced v2.3 software system. 4 μL of hexadecane was dispensed using a micro syringe dispensing system.
Molecular Weight by Size Exclusion Chromatography
A size exclusion chromatography system Alliance 2695™ from Waters Corporation (Milford, Mass.), was provided with a Waters 414™ differential refractive index detector, a multiangle light scattering photometer DAWN Heleos II (Wyatt Technologies, Santa Barbara, Calif.), and a ViscoStar™ differential capillary viscometer detector (Wyatt). The software for data acquisition and reduction was Astra® version 5.4 by Wyatt. The columns used were two Shodex GPC HFIP-806M™ styrene-divinyl benzene columns with an exclusion limit of 2×10 7 and 8,000/30 cm theoretical plates; and one Shodex GPC HFIP-804M™ styrene-divinyl benzene column with an exclusion limit 2×10 5 and 10,000/30 cm theoretical plates.
The specimen was dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) containing 0.01 M sodium trifluoroacetate by mixing at 50° C. with moderate agitation for four hours followed by filtration through a 0.45 μm PTFE filter. Concentration of the solution was circa 2 mg/mL.
Data was taken with the chromatograph set at 35° C., with a flow rate of 0.5 ml/min. The injection volume was 100 μl. The run time was 80 min. Data reduction was performed incorporating data from all three detectors described above. 8 scattering angles were employed with the light scattering detector. No standard for column calibration was involved in the data processing
Thermal Analysis
Glass transition temperature (T g ) and melting point (T m ) were determined by differential scanning calorimetry (DSC) performed according to ASTM D3418-08.
NMR Analysis
13 C NMR data was acquired on a 700 MHz NMR, using a 10 mm probe:
In a first determination, a 310 mg polymer specimen and 30 mg of chromium acetyl acetonate (CrAcAc) were dissolved in deuterated 1,1,2,2tetrachloroethylene (TCE-d2) to 3.1 ml total volume with minimal heating. NMR spectra were acquired using an acquisition time of 1 sec, 90 degree pulse of about 11 μsec, spectral width of 44.6 kHz, recycle delay of 5 sec, temperature of 120° C., 2500-4500 transients averaged. Data processed typically with exponential line broadening of 0.5-2 hz and zero fill of 512 k. Spectra were referenced to TCE-d2 carbon at 74.2 ppm.
In a second determination, a 310 mg polymer specimen and 30 mg of CrAcAc were dissolved in deuterated 1,1,1,3,3,3-hexafluoro-2-propanol-d2 (TCE-d2) to about 2.4 ml total volume with a dmso-d6 capillary insert for lock. NMR spectra were acquired using acquisition time of 0.64 or 1 sec, 90 degree pulse of =11 μsec, spectral width of 44.6 kHz, recycle delay of 5 sec, temperature at 25° C. and 2500-4500 transients averaged. Data processed with lb of typically 0.5-2 Hz and zero fill of 512 k. Spectra were referenced to DMSO-d6 carbon at 39.5 ppm.
Note Regarding Reactions
In the following examples, when it is stated that the temperature was raised to some temperature, and the reaction vessel held for some period of time, it shall be understood that in all cases, unless specifically noted to have otherwise been the case, the procedure followed was to increase the set point of the heat bath to the stated temperature, allow the heat bath to achieve the set-point temperature, and then to hold the reaction vessel for the indicated period of time after the heat bath had come to the set point temperature.
It shall further be understood that stirring at the last stated speed was maintained throughout all steps in the reactions described, unless expressly stated otherwise.
Example 1 and Comparative Example A (CE A)
Copolymer from Oligomers of 3-GT and 3-GF 16 -iso, Long Polycondensation Time
A. Synthesis of (dimethyl 5-(1,1,2-trifluoro-2-(1,1,2,3,3,3-hexafluoro-2-(perfluoropropoxy)propoxy)ethoxy)isophthalate (F 16 -iso)
Anhydrous THF (12 liters) and dimethyl 5-hydroxy-isophthalate (2100 g) were combined under nitrogen in an oil jacketed 22 liter RB flask equipped with a condenser, mechanical stirrer, pressure equalizing addition funnel. To this stirred solution was added anhydrous potassium carbonate (345 g), followed by 1,1,1,2,2,3,3-heptafluoro-3-(1,1,1,2,3,3-hexafluoro-3-(1,2,2-trifluorovinyloxy)propan-2-yloxy)propane (4750 g). Ca. 2 liters of additional THF was used to wash all the reagents into the reaction vessel. The resulting mixture was refluxed for 12.0 hours.
Next day, the cool reaction mixture was filtered, to remove the potassium carbonate and the resulting solution concentrated via rot-evaporation. The resulting material was fractional vacuum distilled to give three fractions:
Fraction Wt. (g) NMR Analysis 1 130 THF and Product 2 2714 Product 3. 2503 Product
Recovered heel: 897 g.
Proton NMR of the reaction at this stage showed almost complete conversion to the desired material. 1H NMR (CDCl3, ppm))=8.56 (s, 1H, Ar—H), 7.95 (s, 2H, Ar—H), 6.05 (d, 1H, CF2-CFH—O), 3.89 (s, 6H, COO—CH3)
B. Preparation of 3-GF 16 -iso Homopolymer from F 16 -iso and 1,3-propanediol
150 g of the F 16 -iso prepared in Example 1 Section A and 32 g of 1,3-propanediol were charged to an oven-dried 500 mL three necked round bottom flask equipped with an overhead stirrer and a distillation condenser. The reactants were stirred under a nitrogen purge at a speed of 50 rpm while the condenser was kept at 23° C. The contents were degassed three times by evacuating down to a pressure of 100 Torr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst (45 mg) was added after the first evacuation. The flask was immersed into a preheated metal bath after the three degassing/repressurization cycles set at 210° C. and held for 90 minutes while stirring speed was increased from 50 to 180 rpm. Following the 90 minute hold, the nitrogen purge was discontinued and a vacuum ramp was started such that after about 60 minutes the vacuum reached a value of 50-60 mTorr. The reaction was held under vacuum at 50-60 mTorr for an additional 60 minutes with stirring at 180 rpm. The reaction vessel was then removed from the heat source. The over-head stirrer was stopped and elevated from the floor of the reaction vessel. The vacuum was then turned off and the system was purged with N 2 gas at atmospheric pressure. The thus formed product mixture was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer. Yield=88%.
1 H-NMR (CDCl 3 ) δ:8.60 (ArH, s, 1H), 8.00 (ArH—, s, 2H), 7.70 (ArH, s, 4H), 6.15 (—CF 2 —CFH—O—, d, 1H), 4.70-4.50 (COO—CH 2 —, m, 4H), 3.95 (—CH 2 —OH, t, 2H), 3.85 (—CH 2 —O—CH 2 —, t, 4H), 2.45-2.30 (—CH 2 —, m, 2H), 2.10 (—CH 2 —CH 2 —O—CH 2 —CH 2 —, m, 4H).
Thermal data: T g =5° C. No melting point was observed. M n =9.1×10 3 Da M w =16.6×10 3 Da
C. Preparation of 3-GT Homopolymer of dimethylterephthalate and 1,3-propanediol
Dimethylterephthalate (150 g), and 1,3-propanediol (105.9 g) were charged to an oven-dried 500 mL three necked round bottom flask equipped with an overhead stirrer and a distillation condenser. The reactants were stirred under a nitrogen purge at a speed of 10 rpm while the condenser was kept at 23° C. The contents of the flask were degassed three times by evacuating down to 500 mTorr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst (94 mg) was added after the first evacuation. Following the three degassing cycles, the flask was immersed into a preheated metal bath set at 160° C. The solids were allowed to completely melt at 160° C. for 20 minutes while the stirring speed was slowly increased to 180 rpm. The temperature was increased to 210° C. and was held at 210° C. for 90 minutes. After 90 minutes at 210° C., the temperature was increased to 250° C. after which the nitrogen purge was discontinued, and a vacuum ramp was started such that after about 60 minutes the vacuum reached a value of about 60 mTorr. After an additional 30 minutes at 250° C. and 60 mTorr, the heat source was removed. The over-head stirrer was stopped and elevated from the floor of the reaction vessel. The vacuum was then turned off and the system purged with N 2 gas at atmospheric pressure. The thus formed product was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer. Yield=85% of 3GT polymer.
1 H-NMR (CDCl 3 /TFA-d): δ8.25-7.90 (ArH—, m, backbone), 7.65 (ArH, s, cyclic dimer), 4.75-4.45 (COO—CH 2 —, m, backbone), 3.97 (HO—CH 2 —R, t-broad, end group), 3.82 (—CH 2 —O—CH 2 —, t, backbone DPG), 2.45-2.05 (—CH 2 —, m, backbone).
Thermal data: T g =55° C., T m =230° C. M n =8.5×10 3 Da M w =16.1×10 3 Da.
D. Preparation of 3-GF 16 -iso-co-3-GT Copolymer
15.3 g of the 3-GT prepared in Example 1 Section C and 46 g of the 3-GF 16 -iso prepared in Example 1 Section B were charged to an oven-dried 250 mL three necked round bottom flask equipped with an overhead stirrer and a distillation condenser kept at 23° C. The contents of the flask were degassed once by evacuating down to 150 mTorr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst (18 mg) was added after the evacuation and repressurization. The nitrogen purge was then discontinued, and a vacuum ramp was started such that after about 30 minutes the vacuum reached a value of about 60 mTorr. The flask was then immersed into a preheated metal bath set at 250° C., and the contents of the flask were allowed to melt and equilibrate for 10 minutes. Stirring was initiated and slowly increased to 180 rpm, and the molten contents of the flask were held under stirring for 3 hours in the 250° C. bath. After 3 hours at 250° C., 60 mTorr, and stirring at 180 rpm, the heat source was removed. The over-head stirrer was stopped and elevated from the floor of the reaction vessel. The vacuum was then turned off, and the system was purged with N 2 gas at atmospheric pressure. The thus formed product was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer.
Yield was approximately 90% of an opaque product designated 3-GF 16 -iso-co-3-GT.
13 C-NMR (TCE-d2): δ62.9 (E) 62.7 (D) 62.4 (G) 62.2 (F); B=0.8.
Thermal data: T g1 =18° C., T g2 =54° C., T m =219° C. M n =59.0×10 3 Da M w =118.5×10 3 Da.
CE-A. Copolymerization of dimethylterephthalate F 16 -iso and 1,3-propanediol
Dimethylterephthalate (30.1 g), F 16 -iso (100 g), and 1,3-propanediol (42.6 g) were charged to an oven-dried 500 mL three necked round bottom flask equipped with an overhead stirrer and a distillation condenser kept at 23° C. The reactants were stirred under a nitrogen purge at a speed of 50 rpm. The contents were degassed three times by evacuating down to 100 Torr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst [40 mg] was added after the first evacuation. The flask was immersed into a preheated metal bath set at 160° C. The solids were allowed to completely melt at 160° C. for 20 minutes after which the stirring speed was slowly increased to 180 rpm. The temperature was increased to 210° C. and maintained for 90 minutes. After 90 minutes at 210° C., the nitrogen purge was discontinued, and a vacuum ramp was started such that after an additional 60 minutes the vacuum reached 50-60 mTorr. The reaction was held under stirring 180 rpm for 3 hours still at 210° C. after which the reaction vessel was removed from the heat source. The over-head stirrer was stopped and elevated from the floor of the reaction vessel. The vacuum was then turned off and the system purged with N 2 gas at atmospheric pressure. The thus formed product was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer. Yield=90% of a clear product.
1 H−NMR (CDCl 3 ) δ:8.60 (ArH, s, 1H), 8.15-8.00 (ArH—, m, 2+4H), 7.65 (ArH, s, 4H), 6.15 (—CF 2 —CFH—O—, d, 1H), 4.70-4.50 (COO—CH 2 —, m, 4H), 3.95 (—CH 2 —OH, t, 2H), 3.85 (—CH 2 —O—CH 2 —, t, 4H), 2.45-2.30 (—CH 2 —, m, 2H), 2.10 (—CH 2 —CH 2 —O—CH 2 —CH 2 —, m, 4H).
13 C-NMR (CDCl 3 ) δ:62.6 62.4 62.1 62.0; B=1.
Thermal data: T g =23° C. Only one T g was observed. No melting point was observed. M n =12.6×10 3 Da M w =24×10 3 Da.
Example 2
Copolymer from Oligomers of 3-GT and 3-GF 16 -iso Short Polycondensation Time
The materials produced in Example 1 Sections A, B, and C were employed as described in Example 2 Section D, infra.
D. Preparation of 3-GF 16 -iso-co-3-GT Copolymer of 3-GF 16 -iso and 3-GT
15.3 g of the 3-GT prepared in Example 1 Section C, supra, and 46 g of the 3-GF 16 -iso prepared in Example 1 Section B, supra, were charged to an oven-dried 250 mL three necked round bottom flask equipped with an over-head stirrer and a distillation condenser kept at 23° C. The reaction mass was kept under nitrogen purge. The contents were degassed once by evacuating down to 150 mTorr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst (18 mg) was added after the evacuation and repressurization. The nitrogen purge was then discontinued, and a vacuum ramp was started such that after about 30 minutes the vacuum reached a value of about 60 mTorr. The flask was then immersed into a preheated metal bath set at 250° C., and the contents of the flask were allowed to melt and equilibrate for 10 minutes. Stirring was initiated and the speed was slowly increased to 180 rpm, and the molten contents of the flask was left under stirring for 60 minutes in the 250° C. bath. The heat source was then removed. The over-head stirrer was stopped and elevated from the floor of the reaction vessel. The vacuum was then turned off, and the system purged with N 2 gas. The thus formed product was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer. Yield=95.7% of an opaque product.
13 C-NMR (TCE-d2) δ62.9 (E) 62.7 (D) 62.4 (G) 62.2 (F); B=0.63.
Thermal data: T g1 =16.8° C., T g2 =51° C., T m =222.5° C. M n= 31.7×10 3 Da M w =65×10 3 Da.
Example 3
Copolymer from 3-GT and 3-GF 16 -iso oligomer
The oligomeric 3-GF 16 -iso prepared in Example 1 Section B was employed in Example 3 Section C, infra.
C. Preparation of 3-GF 16 -iso-co-3-GT Copolymer of 3-GF 16 -iso and 3-GT
The procedures of Example 1 Section D were replicated except that 15.3 g of Sorona® Bright poly(trimethylene terephthalate) resin (1.02 I.V. available from The Dupont Company, Wilmington, Del.) were substituted for the 3-GT oligomer prepared in Example 1 Section C, and the reaction vessel was held at 250° C. for 90 minutes rather than 3 hours. Yield=82.6% of an opaque product.
13 C-NMR (TCE-d2) δ62.9 (E) 62.7 (D) 62.4 (G) 62.2 (F); B=0.56.
Thermal data: T g1 =17° C., T g2 =56.1° C., T m =220.1° C. M n =100.6×10 3 Da M w =199.6×10 3 Da.
Example 4 and Comparative Example B (CE B)
A. Synthesis of Dimethyl 5-(1,1,2-trifluoro-2-(perfluoropropoxy)ethoxy)isophthalate (F 10 -iso):I
Anhydrous THF (12 liters) and dimethyl 5-hydroxy-isophthalate (2100 g) were combined under nitrogen in an oil jacketed 22 liter RB flask equipped with a condenser, mechanical stirrer, pressure equalizing addition funnel. To this stirred solution was added anhydrous potassium carbonate (1035 g), followed by 1,1,1,2,2,3,3-heptafluoro-3-(1,2,2-trifluorovinyloxy)propane (3192 g). Ca. 2 liters of additional THF was used to wash all the reagents into the reaction vessel. The resulting mixture was refluxed for 10.5 hours.
Next day, the cool reaction mixture was filtered, to remove the potassium carbonate and the resulting solution concentrated via rot-evaporation. The resulting material was fractional vacuum distilled to give three fractions:
Fraction Wt. (g) NMR Analysis 1 102 Mixture of Product and THF 2 2526 Product. 3 1167 Product
Recovered Heel: 676 g
Proton NMR of the reaction at this stage showed complete conversion to the desired material. 1H NMR (CDCl3, ppm))=8.54 (s, 1H, Ar—H), 7.97 (s, 2H, Ar—H), 6.07 (d, 1H, CF2—CFH—O), 3.89 (s, 6H, COO—CH3)
B. Preparation of Homopolymer 3-GF 10 -iso
150 g of the F 10 -iso prepared in Example 4 Section A, supra, and 43.1 g of 1,3-propanediol were charged to an oven-dried 500 mL three necked round bottom flask equipped with an overhead stirrer and a distillation condenser kept at 23° C. The reactants were stirred under a nitrogen purge at a speed of 50 rpm. The contents were degassed three times by evacuating down to 100 Torr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst (45 mg) was added after the first evacuation. The flask was then immersed into a preheated metal bath set at 160° C. and held for 20 minutes while slowly increasing the stirring speed to 180 rpm after which the temperature was increased to 210° C. and the reaction flask was held for an additional 90 minutes still at 180 rpm. Following the 90 minute hold, the nitrogen purge was discontinued and a vacuum ramp was started such that after about 60 minutes the vacuum reached a value of 50-60 mTorr. The reaction was held for an additional 90 minutes with stirring at 180 rpm. The heat source was then removed. The over-head stirrer was then stopped and elevated from the floor of the reaction vessel. The vacuum was then turned off, and the system was purged with N 2 gas. The thus formed product was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer. Yield=82.6%.
1 H-NMR (CDCl 3 ) δ:8.60 (ArH, s, 1H), 8.00 (ArH—, s, 2H), 7.70 (ArH, s, 4H), 6.15 (—CF 2 —CFH—O—, d, 1H), 4.70-4.50 (COO—CH 2 —, m, 4H), 3.95 (—CH 2 —OH, t, 2H), 3.85 (—CH 2 —O—CH 2 —, t, 4H), 2.45-2.30 (—CH 2 —, m, 2H), 2.10 (—CH 2 —CH 2 —O—CH 2 —CH 2 —, m, 4H).
Thermal data: T g =22.6° C. No melting point was observed. M n =17.1×10 3 Da M w =21.2×10 3 Da.
C. Preparation of 3-GF 10 -iso-co-3-GT Copolymer of 3-GF 10 -iso and 3-GT
20 g of the 3-GT polymer prepared in Example 1 Section C and 46 g of the 3-GF 10 -iso prepared in Example 4 Section B were charged to an oven-dried 250 mL three necked round bottom flask equipped with an overhead stirrer and a distillation condenser kept at 23° C. The reaction mass was kept under N 2 purge atmosphere. The contents were degassed once by evacuating the reaction flask down to 150 mTorr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst (20 mg) was added after the evacuation and repressurization. The nitrogen purge was then discontinued, and a vacuum ramp was started such that after about 30 minutes the vacuum reached a value of about 60 mTorr. The reaction flask was then immersed into a preheated metal bath set at 250° C. and the contents of the reaction flask were allowed to melt and equilibrate for 10 minutes. Stirring was initiated and speed was slowly increased to 180 rpm. The thus formed melt was left under vacuum with stirring for 15 minutes. The heat source was then removed. The over-head stirrer was then stopped and elevated from the floor of the reaction vessel. The vacuum was turned off, and the system was purged with N 2 gas. The thus formed product was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer. Yield 91.2% of turbid product.
13 C-NMR (TCE-d2) δ62.9 (E) 62.7 (D) 62.4 (G) 62.2 (F); B=0.56.
Thermal data: T g1 =28.1° C., T g2 =51.8° C., T m =216° C. M n =40.6×10 3 Da M w =64.3×10 3 Da.
CE-B. Copolymer of dimethylterephthalate F 10 -iso and 1,3-propanediol
12.2 g of dimethylterephtalate, 30 g of the F 10 -iso prepared in Example 4 Section A, supra, and 17.25 g of 1,3-propanediol were charged to an oven-dried 500 mL three necked round bottom flask equipped with an overhead stirrer and a distillation condenser kept at 23° C. The reactants were stirred under a nitrogen purge at a speed of 50 rpm. The contents were degassed three times by evacuating down to 100 Torr and refilling back to atmospheric pressure with N 2 gas. Tyzor®TPT catalyst (13 mg) was added after the first evacuation. The reaction flask was immersed into a preheated metal bath set at 160° C. The solids were allowed to completely melt at 160° C. for 20 minutes, after which the stirring speed was slowly increased to 180 rpm. The temperature was increased to 210° C. and maintained for 60 minutes. After 60 minutes, the nitrogen purge was discontinued, and a vacuum ramp was started such that after an additional 60 minutes the vacuum reached 50-60 mTorr. As the vacuum stabilized, the stirring speed was increased to 225 rpm and the reaction held for 3 hours. The heat source was then removed. The over-head stirrer was stopped and elevated from the floor of the reaction vessel. The vacuum was then turned off and the system was purged with N 2 gas at atmospheric pressure. The thus formed product was allowed to cool to ambient temperature. The product was recovered after carefully breaking the glass with a hammer. Yield=90% of clear product.
1 H-NMR (CDCl 3 ) δ:8.60 (ArH, s, 1H), 8.15-8.00 (ArH—, m, 2+4H), 7.65 (ArH, s, 4H), 6.15 (—CF 2 —CFH—O—, d, 1H), 4.70-4.50 (COO—CH 2 —, m, 4H), 3.95 (—CH 2 —OH, t, 2H), 3.85 (—CH 2 —O—CH 2 —, t, 4H), 2.45-2.30 (—CH 2 —, m, 2H), 2.10 (—CH 2 —CH 2 —O—CH 2 —CH 2 —, m, 4H).
13 C-NMR (CDCl 3 ) δ:62.6 62.4 62.1 62.0; B=1.
Thermal data: T g =34° C. Only one T g was observed. No melting point was observed. M n= 129.7×10 3 Da M w =2212×10 3 Da.
Example 5
Copolymer from Oligomers of 4-GT and 3-GF 16 -iso
The 3-GF 16 -iso prepared in Example 1 Section B was employed herein.
C. Preparation of Homopolymer of dimethylterephthalate and 1,4-butanediol (4-GT)
Example 1 Section C was repeated except that 129.4 g of dimethylterephthalate instead of 150 g thereof, 118.9 g of 1,4-butanediol were used in place of the 105.9 g of 1,3-propanediol, and 165 mg of Tyzor® TPT were used instead of the 94 mg thereof employed in Example 1.
Yield=79%. 1 H-NMR (CDCl 3 /TFA-d): δ8.25-7.95 (Ar H —, m, backbone), 4.70-4.30 (COO—C H 2 —, m, backbone), 2.20-1.80 (—CH 2 —, m, backbone). Thermal data: T g =42.4° C., T m =223° C. M n =10.9×10 3 Da M w =19.2×10 3 Da.
D. Preparation of Copolymer 3-GF 16 -iso-co-4-GT
Example 1 Section D was repeated except that 20 g of the 4-GT homopolymer prepared in Example 5 Section C were substituted for the 15.3 g of 3-GT in Example 1, 59.4 g of the 3-GF 16 -iso prepared in Example 1 Section B were used instead of the 46 g used in Example 1 Section D, 23 mg of Tyzor® TPT was used instead of the 18 mg used in Example 1 Section D, and the reaction vessel was held for 2 hours at 250° C. instead of 3 hours as in Example 1 Section D.
Yield=91.9% of an opaque product.
13 C-NMR (TCE-d2): δ62.8 (E) 62.6 (D) 62.6 (G) 62.4 (F); B=0.65.
Thermal data: T g1 =11.1° C., T g2 =47.2° C., T m =206.8° C. M n =86.6×10 3 Da M w =208.6×10 3 Da.
Example 6
Copolymer from Oligomers of 2-GT and 3-GF 16 -iso
The 3-GF 16 -iso prepared in Example 1 Section B was employed herein.
C. Preparation of Copolymer of Dimethylterephthalate, Dimethylisophthalate and Ethyleneglycol (2-GT)
Example 1 Section C was repeated except that: a combination of 145.5 g of dimethylterephthalate and 3.9 g of dimethylisophthalate were used in place of the 150 g of dimethylterephthalate; 95.6 g of 1,2-ethanediol were used in place of the 105.9 g of 1,3-propanediol; and, the metal bath was set to 260° C. instead of 250° C. Yield=55%.
1 H-NMR (CDCl 3 /TFA-d): δ8.60 (ArH, s, 1H), 8.25-7.95 (Ar H —, m, backbone), 4.80-4.45 (COO—C H 2 —, m, backbone).
Thermal data: T g =81.5° C., T m =248.9° C. M n =14.1×10 3 Da M w =27.1×10 3 Da.
D. Preparation of Copolymer 3-GF 16 -iso-co-2-GT
Example 1 Section D was repeated except that 20 g of the 2-GT polymer prepared in Example 6 Section C was substituted for the 15.3 g of the 3-GT in Example 1 Section D, 68 g of the 3-GF 16 -iso was used in place of the 46 g thereof in Example 1 Section D, 26 mg of Tyzor®TPT was added instead of 18 mg thereof, the bath temperature was 270° C. instead of 250° C. as in Example 1 Section D, and the reaction time was 2 hours at 270° C., 60 mTorr, with stirring at 180 rpm instead of 3 hours at 250° C. with stirring at 180 rpm as in Example 1 Section D. Yield=93% of an opaque product.
13 C-NMR (TCE-d2): δ63.4 (E) 63.2 (D) 62.6 (G) 62.4 (F); B=0.61.
Thermal data: T g1 =15.5° C., T g2 =77.3° C., T m =217.9° C. M n =76.6×10 3 Da M w =215.4×10 3 Da.
Examples 7-9 and Comparative Examples C-E
The 3-GF 16 -iso-co-3-GT copolymer of Example 1 and the copolymer of CE-A were separately chopped into one inch sized pieces that were placed in liquid nitrogen for 5-10 minutes, followed by charging to a Wiley mill fitted with a 6 mm screen. Each sample was milled at ca. 1000 rpm to produce coarse particles having a maximum dimension of about ⅛″. The particles were dried under vacuum and allowed to warm to ambient temperature.
The two batches of particles were dried overnight in a vacuum oven at ambient temperature under a slight nitrogen purge. Sorona® Bright (1.02 dl/g IV) poly(trimethylene terephthalate) (PTT) pellets available from the DuPont Company were dried overnight in a vacuum oven at 120° C. under a slight nitrogen purge. Blends of each of the copolymers with the Sorona® were prepared in a DSM microcompounder at 1, 2.5, and 5% by weight of the particles with respect to the total weight of the blends. The DSM system is a PC controlled 15 cubic centimeter (cc), co-rotating, intermeshing (self wiping), 2-tipped, conical twin-screw machine with a recirculation loop, discharge valve, nitrogen purge system, and with three different heating zones. 250° C. was used for all three heat zones. Polymer melt temperature was in the range of 230-235° C. Under nitrogen Sorona® and the respective copolymer were charged and stirred at a speed of 150 rpm for a total mixing time of 5 minutes. Following the mixing time, the discharge valve was opened and an extruded one inch wide, 0.015 inch thick, 10 foot long sheet collected. Advancing and receding surface contact angles of hexadecane were determined as described supra. Results are shown in Table 1 below. Also shown in Table 1 is the contact angle for an unblended film of Sorona® Bright PTT.
TABLE 1
Copolymer
Hexadecane
Concentration
Contact Angle (deg.)
Example
(Wt-%)
Advancing
Receding
7
1
46.3
37.0
8
2.5
61.6
40.9
9
5
68.5
42.2
CE-C
1
39.0
23.0
CE-D
2.5
54.7
33.6
CE-E
5
66.0
43.4
Sorona ®
0
<10 (fully
Bright
wetted)
Examples 8 and 9; Comparative Examples C and D
A. Milling
Additional ⅛″ particles were prepared of the 3-GF 16 -iso-co-3-GT copolymer prepared in Example 1 Section D by following the procedures described in Example 7 Section A.
B. Preparation of a Polymer Blend
Sorona® Bright (1.02 dl/g IV) poly(trimethylene terephthalate) (PTT) pellets available from the DuPont Company were dried overnight in a vacuum oven at 120° C. under a slight nitrogen purge. The 3-GF 16 -iso-co-3-GT copolymer particles prepared in Example 1 Section D above were dried overnight in a vacuum oven at ambient temperature under a slight nitrogen purge. Prior to melt compounding the thus dried particles of 3-GF 16 -iso-co-3-GT and pellets of Sorona® Bright were combined together to form a batch with a concentration of 2 wt-% of the 3-GF 16 -iso-co-3-GT copolymer based upon the total weight of the blend. The thus combined particles and pellets were mixed in a plastic bag by shaking and tumbling by hand.
The thus mixed batch was placed into a K-Tron T-20 (K-Tron Process Group, Pittman, N.J.) weight loss feeder feeding a PRISM laboratory co-rotating twin screw extruder (available from Thermo Fisher Scientific, Inc.) equipped with a barrel having four heating zones and a diameter of 16 millimeter fitted with a twin spiral P1 screw. The extruder was fitted with a ⅛″ diameter circular cross-Section single aperture strand die. The nominal polymer feed rate was 3-5 lbs/hr. The first barrel Section was set at 230° C. and the subsequent three barrel Sections and the die were set at 240° C. The screw speed was set at 200 rpm. The melt temperature of the extrudate was determined to be 260° C. by inserting a thermocouple probe into the melt as it exited the die. The thus extruded monofilament strand was quenched in a water bath. Air knives dewatered the strand before it was fed to a cutter that sliced the strand into about 2 mm length blend pellets.
C. Melt Spinning
Referring to FIG. 3 , the blended pellets of polymer thus made, 301 , were charged to a steel cylinder, 302 , and topped of with a Teflon® PTFE plug, 303 . A hydraulically driven piston, 304 , compressed the particles, 301 , into a melting zone provided with a heater and heated to 260° C., 305 , where a melt, 306 , was formed, and the melt then forced into a separately heated, 307 , round cross-Section single-hole spinneret (0.012 inches in diameter, 0.036 inches in length), 308 , heated to 265° C. Prior to entering the spinneret, the polymer passed through a filter pack, not shown. The melt was extruded into a single strand of fiber, 309 , at a rate of 0.8 g/min. The extruded fiber was passed through a transverse air quench zone, 310 , and thence to a wind-up, 311 . Two fiber samples were prepared, one at a wind-up speed of 700 m/min (Example 8) and one at a wind-up speed of 1430 m/min. Control fibers of Sorona® Bright were also spun under conditions identical to those of Examples 8 and 9 respectively (Comparative Examples C and D). In each case, the single filament strands were spun for 30 minutes, and in each case the filament spun smoothly without breaks. The resulting fiber in each case was flexible and strong as determined by pulling and twisting by hand.
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Disclosed are block copolyesters comprising blocks of fluoroether functionalized aromatic polyester and blocks of unmodified aromatic polyester, the block copolyesters having a blockiness index, B, in the range of 0.25 to 1.0. The block copolymers incorporated into blends with unmodified aromatic polyester impart oil and soil resistance to shaped articles prepared from the blends.
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FIELD OF THE INVENTION
[0001] The present invention relates to the formation of doors. In particular, the present invention relates to the formation of a door from a composite of a thermoplastic material and an organic fibrous material.
BACKGROUND OF THE INVENTION
[0002] Various materials are used to construct architectural doors. Architectural wood doors are well known. Wood doors, however, when exposed to rain, snow, sun and other elements require frequent maintenance including the application of various stains and clear coats. Wood doors can also warp and are subject to rot. There is a need for a door having low maintenance that is not susceptible to the elements. Various alternatives to wood are available.
[0003] Doors having steel facing panels are common. These steel panel doors are fairly inexpensive to construct and are somewhat dimensionally stable under temperature fluctuations. The initial start up costs associated with producing a steel door is high. High pressure tools are required to form the panels. However, unless the steel panels used have a high thickness, doors constructed with steel panels are subject to denting. In addition, imparting a crisp multi-directional wood grain appearance to a steel panel door is typically not done.
[0004] Doors constructed with fiberglass facing panels are also common. Fiberglass facing panels have significant benefits over steel. Fiberglass facing panels can be constructed to resemble a panelized wooden door. However, fiberglass doors are very expensive to construct. Like steel doors, the start-up costs associated with production are high and production rates are very slow. Expensive molds must be used to produce the panels having a panelized wooden door appearance. The raw materials for fiberglass doors are also relatively expensive. Fiberglass doors also have problems with dimensional stability resulting from temperature fluctuations. Such dimensional stability can eventually damage a door.
[0005] Doors constructed with PVC facing panels are also well known. PVC facing panels are less expensive to produce than the fiberglass panels as manufacturing costs and raw material costs are both less than that of fiberglass panels. However, PVC, like fiberglass, is dimensionally unstable in response to temperature fluctuations. PVC softens considerably at 180° F. As a result, PVC is inappropriate for use in storm doors and doors that are used in combination with storm doors where it is possible to obtain temperatures in excess of 180° F. in the space between the storm door and the door in response to exposure to direct sunlight. For example, the space between a dark painted door and a full view storm door (i.e., large window) can reach up to 230° F. and 240° F. Consequently many materials undergo considerable deterioration when used on an exterior door used in association with a storm door or used as a storm door.
[0006] For the foregoing reasons there is a need for a door constructed with opposing door panels that are manufactured using inexpensive manufacturing techniques and inexpensive raw materials. There is a further need for doors constructed with door panels that are resistant to denting and are dimensionally stable under temperature fluctuations.
[0007] Others have tried to use produce composite materials. These materials, however, are not suitable for use in the formation of composite door skins from both manufacturing and product lifetime perspectives.
[0008] U.S. Pat. Nos. 5,486,553 and 5,539,027, both entitled “Advanced Polymer/Wood Composite Structural Member” to Deaner et al. disclose the formation of structural members from a polymer and wood composite. The structural members are formed from a composite containing 30 to 50 wt-% of sawdust along with 50 to 70 wt-% of a polyvinyl chloride polymer. The composite is first blended and then extruded into pellets. The pellets are then extruded into the desired structural member. The disclosed composite, however, is not suitable for use in the formation of doors because the material may degrade when exposed to high temperatures. Furthermore, the use of the disclosed composite requires additional manufacturing steps. Furthermore, the composite must first be pelletized before formation into the final shape as a structural member. Finally, the final product does not have the appearance of wood.
[0009] U.S. Pat. No. 5,700,555, entitled “Sandable and Stainable Plastic/Wood Composite” to Grill discloses a composite article that may be used to form components of steel, fiberglass or wood door. The article includes a first zone made entirely of plastic and a second zone made of plastic and natural fiber. The first and second zones are integral and are continuously coextruded. The ratio of natural fiber in the second zone is between 10% and 55%. The outer surface of the second zone includes embossing to resemble wood grain. The outer surface has sufficient porosity so as to hold and retain wood stain and paint so that the composite article is stainable to resemble genuine wood. The composition of the second zone may include between 45% and 90% polyvinylchloride, between 10% and 55% natural fiber, and external lubricate and a fusion enhancer.
[0010] U.S. Pat. Nos. 5,827,607, 5,932,334, and 6,015,611, each entitled “Advanced Polymer Wood Composite” to Deaner et al. and U.S. Pat. No. 6,015,612, entitled “Polymer Wood Composite” to Deaner et al. disclose the formation of structural members from a polymer and wood composite. The structural members are formed from a composite containing 30 to 50 wt-% of sawdust along with 40 to 70 wt-% of a polymer containing vinyl chloride and less than 8 wt-% of water. Like the other Deaner et al. references discussed above, the composite is first blended and then extruded into pellets. The pellets are then extruded into the desired structural member, which requires additional manufacturing steps.
[0011] U.S. Pat. No. 5,866,264, entitled “Renewable Surface For Extruded Synthetic Wood Material” to Zehner et al discloses a cellulosic fibrous polymer composite material having a renewable surface that is coextruded therewith.
[0012] U.S. Pat. No. 5,869,138, entitled “Method For Forming Pattern On A Synthetic Wood Board” to Nishibori discloses a method of forming a wood grain pattern on a synthetic wood board. Nishibori discloses a multi-step process for forming a wood grain. The synthetic wood board is first subject to a first grinding process along its entire surface of at least one side. A colorant is then coated on the ground surface. The colorant impregnates in wood meal on the surface. The surface is then subject to a second grinding process and abraded to form woody like appearance. The board is then subject to a grain printing process.
OBJECTS OF THE INVENTION
[0013] It is an object of the present invention to provide a composite door structure using an organic fibrous material.
[0014] It is another object of the present invention to provide a composite door structure formed from a mixture of a thermoplastic polymer and an organic fibrous material.
[0015] It is another object of the present invention to provide a composite door structure having the appearance of wood
[0016] It is another object of the present invention to provide a composite door structure formed from a mixture of a thermoplastic polymer, an organic fibrous material and a coupling agent.
[0017] It is another object of the present invention to provide a composite door structure having a smooth appearance similar to steel.
[0018] It is another object of the present invention to provide a composite door structure having improved thermal properties to withstand exposure to increased temperatures.
[0019] It is another object of the present invention to provide a composite door structure having improved dent impact resistance over steel.
[0020] It is another object of the present invention to provide a composite door structure that is easy to stain or paint.
[0021] It is another object of the present invention to provide a composite door structure having improved maintenance qualities and is not susceptible to rot.
[0022] It is another object of the present invention to provide a method of forming a composite door structure.
SUMMARY OF THE INVENTION
[0023] The present invention provides a method of forming a door. The present invention is also directed to a door constructed in accordance with the method of forming a door. The method includes mixing together a thermoplastic polymer with an organic fibrous material in a ratio such that the organic fibrous material constitutes 40 to 60 percent by weight of the mixture. The mixture may also include a coupling agent, such as for example, a maleated polypropylene. It is contemplated that the coupling agent may constitute 0.5 to 5 percent by weight off the mixture. It is further contemplated that the mixture may include one or more impact modifiers. The impact modifiers improve resistance to dents. The mixture is then extruded under heat and pressure to create a thin sheet form. The sheet is then cut to a predetermined size. Material from at least one surface of the sheet may be partially removed to create a homogeneous appearance devoid of obvious fibrous particles. The surface may be sanded, abraded or treaded. The sheet is then thermoformed to impart on at least one surface an exterior three dimensional door surface to create a thin door facing. The thermoformed sheets may have the appearance of a door facing having raised panels or other suitable textured surface. It is also contemplated that the thermoformed sheets may have a smooth flat surface. It is also contemplated that the surface of the sheet not be treated prior to the thermoforming operation. The surface of the facings has a suitable finish such that painting or staining is unnecessary. The two thermoformed thin door facings, a peripheral frame and a core material are assembled into a door in which the two thin door facings are fixedly held in parallel relation by the peripheral frame and core material with the first surfaces of each thin door facing thereof facing outwardly in opposite directions.
[0024] The method of forming a door of the present invention provides significant benefits over the prior art. The method of forming a door of the present invention is inexpensive because the materials used to manufacture the door facings are inexpensive and the manufacturing techniques used to manufacture the door facings are inexpensive to perform. Specifically, the materials used to manufacture the sheets from which the door facings are manufactured comprise a mixture of thermoplastic polymer and organic fibrous material. The organic fibrous material preferably constitutes 40-60% by weight of the mixture. The mixture may also include a coupling agent. It is contemplated that the coupling agent may constitute 0.5 to 5 percent by weight off the mixture. The organic fibrous material preferably comprises relatively small particles of pine, other suitable inexpensive woods or other fibrous organic materials including but not limited to straw, rice husks and knaff. The organic fibrous material may often be a by-product of other wood manufacturing processes Accordingly, the organic fibrous material may be considered to be part of the waste stream of a manufacturing facility. Using this raw material provides significant benefits to the raw material costs of sheets manufactured from the raw materials. As such, the manufacture of the doors in accordance is more environmentally friendly because it does not require cutting down additional trees for the formation of the panels. Additionally, the sheets from which the door facings are manufactured are also constructed using relatively low cost and high heat resistant thermoplastic polymers such as polypropylene. Finally, door facings are constructed using relatively low cost thermoforming manufacturing techniques such as vacuum forming and compression molding.
[0025] In accordance with the present invention, the exterior surface of the facings may not be stained or painted. Instead, it is contemplated that a thin layer of plastic material may be applied to the thin sheet of the composite material to form the exterior surface of the same. The thin layer of plastic material may be applied one or more ways. It is contemplated that the thin layer of plastic material may be coextruded with the composite mixture. After the coextrusion operation, the thin sheet and the thin layer are thermoformed to form an exterior three dimensional door surface. It is also contemplated that the thin layer of plastic material may be applied by laminating a thin layer of plastic material on to the exterior surface of the thin sheet. Prior to lamination, the exterior surface of the thin sheet may be treated to promote adhesion with the thin layer of plastic material. For example, it is contemplated that the exterior surface may be flame treated, exposed to heat or corona treated.
[0026] Door facings and door slabs constructed in accordance with the present invention are dimensionally stable in response to temperature variations. As the door facings will undergo a minimum of expansion or contraction, the facings will be less likely to delaminate from a frame. It is also likely that cracking and other forms of deterioration will be minimized for doors constructed in accordance with the present invention. This dimensional stability results in doors that are suitable for use in association with storm doors or as storm doors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts and wherein.
[0028] FIG. 1 shows the method of forming a door in accordance with the teachings of the present invention;
[0029] FIG. 2 is an exploded view showing a door constructed in accordance with the teachings of the present invention;
[0030] FIG. 3 is a method of forming a composite door in accordance with another embodiment of the present invention;
[0031] FIG. 4 is a partial schematic diagram illustrating a thin layer of a plastic material formed on the surface of the door facings in accordance with the present invention; and
[0032] FIG. 5 is a method of forming a composite door in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] FIG. 1 shows the method of forming a door in accordance with the present invention. The method involves mixing together a thermoplastic polymer with an organic fibrous material in a ratio such that the organic fibrous material constitutes 40-60% by weight of the mixture. The organic fibrous material is preferably relatively small particles of pine that have passed through a sieve. For example, an 80 mesh sieve may be used. The present invention is not limited to the use of an 80 mesh sieve; rather, other sizes both larger and smaller are considered to be well within the scope of the present invention. The present invention, however, is not limited to the use of pine; rather, it is contemplated that various types of wood dust including but not limited to oak, cherry, maple and combinations of the same or other woods may be used. It is further contemplated that the use organic fibrous material may contain a blend of wood particles, provided that all of the particles have been passed through the sieve. It is further contemplated that other fibrous organic materials may be used including but not limited to straw, rice husks and knaff. The organic material may contain a mixture of wood and other fibrous organic materials.
[0034] The thermoplastic polymer is preferably polypropylene. The polymer is melted and blended with the organic fibrous material either by batch mixing or twin-screw extension to form a homogenous material. The fiber mesh size (preferably 80 mesh) is such that the material has a uniform appearance without obvious particles. It is contemplated that the mixture may include filler materials. For example, ethylene propylene diere monomer (EPDM) may be added to improve impart resistance. Talc powder may be added to increase thermal stability. The presence of talc powder also lightens the color of the extruded mixture.
[0035] In accordance with the present invention, it is preferable that the mixture includes a coupling agent. The presence of the coupling agent increases the adhesion between the components of the mixture. The coupling agent is a maleated polypropylene. The present invention, however, is not limited to the use of a maleated polypropylene; rather, other materials that can improve the adhesion of the components of the mixture are considered to be well within the scope of the present invention. The coupling agent constitutes between 0.5 to 5 percent by weight off the mixture.
[0036] The mixture is then extruded into sheets of thickness preferably between 2 to 4 mm. The sheets are extruded at appropriate widths and cut to appropriate lengths for various door sizes.
[0037] The sheets undergo a material removal process which is preferably sanding, so as to expose the fibrous material within the extended sheets. Preferably the sanding removes material from at least one surface of the sheet. The removal of material through sanding imparts a homogenous appearance to that surface that is devoid of obvious fibrous particles. The sheets are sanded so that the sanded surface may readily accept paint, stain or ink.
[0038] The sheets are then thermoformed preferably through vacuum forming. The sheets may also be thermoformed through compression molding with matched tooling. The thermoforming imparts a three-dimensional door surface on the sheet, thus creating a thin door facing from the sheet. A grain pattern may be imparted on the sanded surface if desired preferably through imprinting the wood grain pattern on the sanded surface.
[0039] As is shown in FIG. 2 , a door assembly 10 is then created through the use of two door facings 111 and 112 . The door assembly shown in FIG. 2 includes a first door facing 111 and a second door facing 112 . The first door facing 111 includes a front surface 12 which is a sanded surface, and a back surface 13 opposite the front surface. The first door facing 111 further includes a first side edge 14 , a second side edge 16 , a top edge 18 , and a bottom edge 20 . The first and second side edges 14 and 16 are preferably parallel to each other. The distance between the first and second side edges 14 and 16 defines the width of the facing 111 . The top edge 18 and the bottom edge 20 are also preferably parallel to each other. The distance between the top edge 18 and the bottom edge 20 defines the length of the facing 111 . A plurality of simulated wood panels 22 have been formed into the facing 111 . The second facing 112 is preferably similarly constructed to the first facing 111 . The second facing 112 preferably includes a sanded surface facing in the opposite direction from the sanded surface 12 of the first facing 111 . The first and second door facings 111 and 112 are attached to a peripheral frame 30 in a substantially parallel relationship to each other. The peripheral frame 30 includes a first vertical frame element 31 , a second vertical frame element 32 , a top frame element 34 , and a bottom frame element 36 . The frame elements 31 , 32 , 34 , and 36 could be manufactured from a variety of materials such as wood, or could be manufactured from a composite material similar to the material used in the door facings 111 and 112 . The frame 30 is shown in a preferred configuration or a rectangle. The door 10 is filled with a core material 50 , only a portion of which is shown in FIG. 2 . The preferred core material is a good insulating material. The use of a polyurethane foam provided better energy efficiency. The core material would preferably fill the entire cavity between the facings 111 and 112 cavity within the frame 30 . It is contemplated that the core material may be provided as a preformed insert. It is also contemplated that the core material may be formed in place between the facings 111 and 112 .
[0040] The facings 111 and 112 simulate the appearance of a multiple paralleled wood door having eight simulated wood panels 22 . However, it is understood that the preferred configuration shown in FIG. 2 is one of many configurations possible. It is also understood that a simulated wood grain could also have been imparted into the sheet prior to or after thermoforming such a wood grain would preferably be imprinted into the sheet. It is further understood that the sanded or abraded surface of the door facing will readily accept paint, stain, ink and other coatings or finishes, which might enhance the appearance of the door. It is further understood that the inner surfaces of the facings 111 and 112 may be abraded to enhance the adhesion with the core material, described above, and/or the adhesive used to secure the door components together. Although the abraded surface is devoid of obvious particles of organic fibrous materials, the organic fibrous particles exposed by the abrading process are able to readily accept paint, stain, ink and other coatings or finishes. It is understood that a material removal process other than sanding could have been used to expose the organic fibrous particles. Other forms of abrading are within the scope of the present invention. It is also contemplated that a corona treatment may be applied to the surfaces of the facings 111 and 112 . The treatment may be applied to the outer surface of the facings 111 and 112 to improve paint adhesion. The tread may be applied to the inner surface of the facings 111 and 112 to improve the adhesion with glue and/or foam located within the interior of the door. It is understood that both facings may include a sanded surface that will readily accept paint, stain, ink and other coatings or finishes. However, it is possible that only the first facing would include a sanded surface. It is also understood that both surfaces of each facing could undergo a material removal process. It is also understood the material removal process could be a process other than abrasive sanding. It is further understood that many frame configurations are possible within the scope of the invention. It is still further understood that the use of many different core materials are possible within the scope of the invention.
[0041] While an advantageous embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention. For example, the exterior surface of the facings may not be stained or painted. It is contemplated that during the process of forming the sheets, the mixture may be coextruded with a plastic layer 60 that forms a top surface, as set forth in FIG. 3 . After the coextrusion operation, the thin sheet 111 or 112 and the thin layer 60 are thermoformed to form an exterior three dimensional door surface. The plastic layer may be formed using ASA plastic 15/1000 or other plastic materials having similar properties. The plastic layer may have a thickness of 0.015″ or thinner. It is also contemplated that the plastic layer may have a greater thickness. This coextrusion provides a pre-finished colored surface (e.g. white or tan) that does not require painting and has good UV resistance. No further finishing is required, it is not necessary to perform the above described abrading operation because there is no need to expose wood fibers for purposes of staining. It is also contemplated that the thin layer of plastic material may be applied by laminating a thin layer of plastic material on to the exterior surface of the thin sheet, as illustrated in FIG. 5 . Prior to lamination, the exterior surface of the thin sheet may be treated to promote adhesion with the thin layer of plastic material. For example, it is contemplated that the exterior surface may be flame treated or corona treated. It is also contemplated that a sanding or grinding operation may be performed on the facings 111 and 112 to enhance the adhesion of the plastic layer to the top surface. It is also contemplated that the plastic layer may be textural during the thermal forming operation if such a textured finish is desired. It is further contemplated that the facings 111 and 112 may be cut to length before or after the application of the plastic layer 60 . It is intended that the present invention covers the modifications and variations of the invention contemplated herein, provided they come within the scope of the appended claims and their equivalents. It is understood that the invention is not to be limited to the disclosed embodiments and elements, but, to the contrary, it is intended to cover various modifications, combinations of features, equivalent arrangements, and equivalent elements.
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A method of forming a composite door is disclosed. The method comprises: mixing together a thermoplastic polymer with an organic fibrous material in a ratio such that the organic fibrous material constitutes 40 to 60 percent by weight of the mixture; extruding the mixture under heat and pressure to create a thin sheet form; cutting the sheet to a predetermined size; removing material from at least one surface of the sheet to create a homogeneous appearance devoid of obvious fibrous particles; thermoforming the sheet to impart to the at least one surface an exterior three dimensional door surface to create a thin door facing; and assembling two of the thermoformed thin door facings, a peripheral frame and a core material into a door.
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This is a continuation of application Ser. No. 06/918,465, filed Oct. 14, 1986 now abandoned.
FIELD OF THE INVENTION
The present invention relates to wall structures and methods, and particularly to a load bearing masonry block residential wall system and method using steel post-tensioning rods.
DESCRIPTION OF THE PRIOR ART
The advantages of masonary construction for residential structural walls are many and include virtual freedom from maintenance as well as structural strength and freedom from insect damage or deliterious effects of aging. However, a desirable characteristic of a residential wall system is a low heat conductivity. The insulation value of a wall has become more important in recent times and the need for the wall to act as a heat barrier has become extremely important. Unfortunately, conventional masonry walls exhibit rather poor insulation characteristics such that other types of structural systems have become more widespread. These other systems, usually wood frame construction or variations thereof, exhibit all of the undesirable characteristics inherent in wood construction including termite susceptibility, fire hazard, possibility of dry rot, dimensional instability, as well as great variation in quality of wood.
Thermal conductivity is a measure of a material's ability to transmit heat therethrough. Wall structures are always composite structures such that the thermal conductivity of an entire wall system is a sum of the conductivities of the individual parts. For example, insulation material within a wall may have a very low heat conductivity whereas the denser materials such as grouting or mortar will have a higher thermal conductivity. In the air conditioning and insulation industries, it has been found more convenient not to rate the individual wall systems in terms of their thermal conductivity, but rather with regard to their thermal resistance. Thermal resistance, or "R" value, is simply a reciprocal of conductivity and is a measure of the wall's ability to insulate, rather than transmit, heat on one side of the wall from the other side of the wall. Therefore, in the comparison of different wall systems, the "R" value is frequently used as a measure of that wall systems ability to insulate the interior of a dwelling from the temperature fluctuations on the exterior of the dwelling.
When comparing the thermal characteristics of the masonry wall versus the wood frame wall, the frame structure usually is far superior, particularly in view of the fact that it is easily insulated. For example, a typical frame construction will consist of spaced studs having four or six inch thickness perpendicular to the wall structure, the outside of which will be covered by plywood or a composition board of some type which in turn will be covered by a siding material or perhaps a composition such as stucco. Typical fiberglass batting is then placed between the studs and the interior wall finished with plaster board or similar interior wall finish. The resulting composite wall structure will normally exhibit an "R" value of from 12 to 20. A typical masonry block construction will include successive courses of masonry block with the inside surface of the wall being furred with wall board placed on the surface of the furring. The wall may or may not include a thin sheet of insulation material and is usually finished on the outside either by applying stucco or simply painting. In some instances, the masonry structure will include insulating material placed in the voids of the respective blocks. Such block structures typically have "R" values ranging from 6 to 10.
Thus, it may be seen that although the masonry construction incorporates substantial advantages over a corresponding frame system, the wood frame wall nevertheless presents substantial advantages in the area of heat insulation.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a wall system incorporating masonry structural techniques while nevertheless providing a high thermal resistance value.
It is also an object of the present invention to provide a novel method for constructing a masonry type wall structure to provide an economical means for erecting a masonry wall having a substantially higher thermal resistance than heretofor achievable in conventional masonry wall structures.
It is another object of the present invention to provide a masonry wall structure that eliminates the use of grout or any other similar substance that would increase the conductivity of the wall structure.
It is still another object of the present invention to provide a masonry wall structure incorporating post-tensioning rods as a means for assuring structural integrity and withstanding wind loads.
These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.
SUMMARY OF THE INVENTION
Briefly, the wall structure and method of the present invention utilizes vertically extending post-tensioning rods that are anchored in the footing of the wall; further, these post-tensioning rods are sectioned to provide convenient erection during the construction of the wall. No conventional reinforcing bar or grouting is used in the wall structure; rather, polyurethane foam is injected into the voids in the masonry blocks while the vertically extending rods extend through a plate positioned on top of the wall. The rods are post-tensioned to a predetermined value; special steel lintels over doorways and window openings provide continuity to the post-tensioning technique while still blocks having openings therein permit access to the interior of the wall for the injection of polyurethane in those places normally considered inaccessible.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may more readily be described by reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a masonry block wall system incorporating the teachings of the present invention.
FIG. 2 is a perspective view of a vertically extending rod attached to a reinforcing bar in the form provided for the footer of the wall of FIG. 1.
FIGS. 3 and 4 are illustrations of partially completed walls constructed in accordance with the method of the present invention.
FIG. 5 is an isometric view of a steel lintel incorporated in the wall system of the present invention.
FIG. 6 is a view of a portion of the wall of FIG. 1 showing a post-tensioned rod extending through the top plate thereof.
FIG. 7 is a perspective view of masonry sill blocks having openings therein and showing a typical polyurethane injection gun used for injecting foam in the wall system of the present invention.
FIG. 8 is a perspective view of a typical masonry block used in the wall system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a masonry block wall 10 is shown comprising a plurality of courses of masonry blocks 11 constructed on a stem wall 12 extending from a footer 14. The wall includes a plurality of vertically extending post-tensioning rods such as that shown at 16, each of which extends through the voids in the respective masonry blocks through a top plate 18. The post-tensioning rods 16 terminate above the plate 18 and are tensioned through the use of nuts 19 bearing upon steel washers 20. The wall also includes a steel lintel 22 which has welded thereto post-tensioning rods such as that shown at 24. Further, the sill incorporates a plurality of sill blocks 26, each of which is provided with an opening such as that shown at 27 for the admission of polyurethane foam. The wall is filled with urethane foam such as that shown at 28.
The wall is constructed by first providing a footer form such as the trench shown at 30 in FIG. 2; the footer includes an anchoring means that may take various forms such as the reinforcing bar 31 positioned horizontally therein and to which is attached a plurality of vertically extending post-tensioning rods such as that shown at 32 in FIG. 2. It may be noted that the bottom portion of the rods 32 are upset and wired to the reinforcing bar 31 by any convenient means such as clips or wire 33. The vertically extending post-tensioning rods 32 through 34 are spaced along the wall at predetermined intervals depending on the specific design of the individual wall, the load the wall is to carry, and other miscellaneous design considerations. Normally, the spacing between adjacent vertically extending post-tensioning rods will be from two feet to six feet. The number of rods indicated in FIG. 1 are for purposes of illustration and are not necessarily correctly spaced.
After the rods are attached to the horizontal reinforcing bar as shown in FIG. 2, the concrete footer is poured and, in most instances, a stem wall such as that shown at 12 will be poured on top of the footer. For simplicity, the term "footer" as used herein includes a stem wall if and when the latter is used. As shown in FIG. 3, the vertically extending rods 32, 33 and 34 are spaced along the wall and extend for a vertical distance substantially less than the height of the wall. In practice, it has been found that the wall system of the present invention may be constructed most expeditously if the vertical length of the rods 32-34 as shown in FIG. 3 is kept to approximately four feet. It will also be noted that each of the vertically extending rods 32-34 are threaded at the respective ends thereof.
Masonry block is then laid on the footer or stem wall as shown in FIG. 4 using conventional masonry techniques with mortar joints. Because of the method and structure of the present invention however, the masonry block may be chosen to be particularly light with a minimum of webbing. For example, the configuration shown in FIG. 8 is illustrative of the type of light weight block that may be used in the wall structure of the present invention. It may be seen that the faces 40 and 41 are interconnected by only a single web member 42 which may be relatively thin in cross-section; in fact, it may be possible for the webbing 42 to be significantly shortened such as shown in FIG. 8 by the broken line 43.
When several courses of masonry block have been laid, such as shown in FIG. 4, a second section such as that shown at 35 is connected to each of the corresponding vertical rods. These second sections extend vertically a distance sufficient to extend through the remaining wall height and through the top plate 18 shown in FIG. 1. It is important to note that the vertically extending post-tensioning rods do not contact the masonry block, nor are they held in position with grouting or other typical masonry products.
When all of the courses of the wall have been completed, polyurethane foam, or similar injectable foaming insulation material, is injected into the voids provided in all of the masonry blocks. Thus the entire interior of the wall is filled with urethane foam. The specific composition of the insulation, and manner in which the block voids are filled may be chosen from numerous prior art available techniques. It may also be possible to inject the urethane foam at various stages of completion of the wall; that is, it may be possible to inject foam after only several courses have been completed although it is more desirable to postpone the foam injection until the last course has been completed.
When the injected foam has set, a wood plate such as that shown at 18 in FIG. 1, having predrilled holes therein to admit the respective post-tensioning rods, is placed on top of the wall; plate washers such as those shown at 20 in FIG. 1 are then placed over the ends of the rods and a nut is threaded on each rod and tightened to a predetermined value. While the specifics of any particular wall will vary from other walls, it has been found that a typical residential load bearing masonry block construction will use 7/16" smooth post-tensioning rods that are post-tensioned to approximately 2200 pounds each.
When openings are provided in the wall, such as the window opening shown in FIG. 1, a steel lintel is provided to provide continuity to the post-tensioning. Referring to FIG. 5, a typical steel lintel 60 is shown having a reinforcing ridge 61 formed integral therewith or welded thereto; further, post-tensioning rods 62, 63 and 64 are welded to the lintel in accordance with the predetermined spacing. The post-tensioning rods extend vertically a sufficient distance to protrude through the top plate of the wall; each of the rods 62-64 is threaded to accept a nut for tensioning. It may be noted that post-tensioning the rods 62-64 will not result in the anchoring of the wall to the footer; rather, the vertically extending post-tensioning rods extending from the steel lintel will insure structural integrity and unity to that portion of the wall over the opening or window and will lock that portion of the wall to the adjacent portions of the wall having vertically extending post-tensioning rods extending from the top plate into the footer.
The sills of such opening as the window opening shown in FIG. 1 are provided with sill blocks 26 as most clearly shown in FIG. 7. Each of the sill blocks includes an opening 27 to permit the injection of polyurethane foam into that portion of the wall beneath the window. The apparatus 70 shown in FIG. 7 is a typical urethane injecting gun shown positioned to inject urethane foam into one of the openings 27 in the sill block 26.
Those skilled in the art will recognize that many modifications may be made in the present invention without departing from the spirit thereof. For example, it may be desirable to use horizontal joint reinforcing in the form of a spaced wire mesh in some particular applications. This latter technique is well known and need not be discussed here. Similarly, the specific spacing of the post-tensioning rods, as well as the rod diameter and the particular tension placed on the rod may vary from that described. In some instances, it may be possible for the anchoring means to be imbedded in the stem wall, and a tying arrangement provided to transmit force of the post-tensioning rods to the footer. In such circumstances, for purposes of the present invention, the stem will be considered as part of the footer.
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A masonry block system is disclosed incorporating a plurality of courses of masonry block, each block of which is formed with minimum webbing to minimize heat flow therethrough. The wall system is formed into a unitary structure through the utilization of post-tensioning rods tied to reinforcing rods in the wall footer and extending through the voids in the respective blocks to a top plate positioned on top of the wall. The rods are threaded and are post-tensioned; the voids contain a polyurethane foam.
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RELATED APPLICATIONS
[0001] There are no related patent applications.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
[0003] None.
BACKGROUND OF THE INVENTION
[0004] 1. Field of Invention
[0005] The present invention is directed to an intracoronally supported dental prosthesis that can be formed in place during one sitting or visit to the dentist.
[0006] 2. Description of the Prior Art
[0007] Dental prosthesis of the general type considered here are conventionally planned, constructed and installed over a period of time and requires two or more visits to the dentist's office. Initially the dentist will make measurements, and the pontic is then prepared by a dental lab pursuant to the dentist's specifications. When the dentist is satisfied with the configuration and color of the pontic, he or she will then install it by support means attached to the adjacent teeth. This is a satisfactory process and results in an excellent dental prosthesis, when time and circumstances are favorable. However, such a procedure takes considerable time and is costly. Sometimes, the circumstances for such a procedure are not favorable and time is limited. For instance, in remote areas or third world countries, the visiting dentist is going to see the patient only once or over an extended period of time if multiple visits are required. Circumstances do not permit multiple visits to the dentist and there are no dental labs conveniently nearby.
[0008] So far as applicant is aware, the most relevant prior art are applicant's own patents, U.S. Pat. No. 5,888,068 to Lans et al. issued Mar. 30, 1999 and U.S. Pat. No. 6,050,820 to Lans et al. issued Apr. 18, 2000. The '068 patent discloses an intracoronally supported dental pontic including opposing wings for anchoring the device into adjacent teeth. In use, parallel slots are drilled into the interior sides of the teeth adjacent a missing tooth. The slots are formed to correspond with the wings of the inventive device such that the prosthetic device is then inserted from behind and into the prepared space. The '820 patent discloses the improvement whereby the pontic further comprises a matrix folded to form a horizontal top portion and a vertical bottom portion, thereby increasing the structural rigidity of the device. As compared to the device of the '068 patent, the device of the '820 patent is able to withstand greater forces during, for example, mastication, and exhibits greater durability.
[0009] These teachings do not aid in the resolution of a number of practical difficulties that are resolved by the present invention.
SUMMARY OF THE INVENTION
[0010] The present invention is directed towards a dental prosthesis' body formed of two halves separated by a seam. Three rigid wire members extend through bores formed through the body matrix, and have opposite ends which extend beyond the matrix. The two halves of the body can be moved away from one another so as to extend the width of the prosthesis to adjust to the width of the gap it is intended to fill. When the body of the prosthesis has been appropriately adjusted, the face of the prosthesis is applied to the matrix. When it is colored and continued to the dentist's satisfaction, it is then permanently installed, by the means of slots drilled in adjacent teeth, into which the protruding wire ends are fitted and secured by cured resin.
[0011] It is an object of the present invention to provide a dental prosthesis that can be formed and permanently installed by a dentist in the course of a single visit
[0012] These and other objects, advantages, and novel features of the present invention will become apparent when considered with the teachings contained in the detailed disclosure along with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will be described with reference to the appended Figures, in which:
[0014] FIG. 1 is front elevational view of the dental prosthesis;
[0015] FIG. 2 is the same view as FIG. 1 , but with the two halves of the prosthesis in an expanded position;
[0016] FIG. 3 is a cross sectional view of the prosthesis matrix taken along dotted line 4 of FIG. 1 ;
[0017] FIG. 4 is the same view as FIG. 3 , but with the pontic face applied; and
[0018] FIG. 5 is a rear elevational view of the prosthesis, mounted between adjacent teeth of a patient.
DESCRIPTION OF THE INVENTION
[0019] The best mode and preferred embodiment of the present invention is shown in FIGS. 1-5 .
[0020] Directing attention to FIG. 1 of the drawings, a dental prosthesis body 1 , is fabricated from micro-hybrid glass filled composite resin. The body can also be made of nano-filled composite resin, methacrylate based resin or other similar material by means of a stamping, cutting or injection molding process. The body 1 comprises a left half section 2 and a right half section 3 . When the two sections 2 and 3 are placed adjacent each other, a seam 4 separates the left half section 2 from the right half section 3 . Throughgoing apertures 5 are formed through the front face and rear face of the body horizontally through matrix 1 . Wires 6 extend through the middle of body matrix 1 and opposite ends of wires 6 , protrude beyond the opposite sides of the body matrix 1 . The wires 6 extend through bores or channels 7 formed or cut in body 1 , but are not adhered, so that the body 1 is moveable relative to wires 6 .
[0021] As shown in FIG. 5 , the prosthesis is used to fill the gap created by a missing tooth. It is attached to and supported by the two adjacent teeth 10 and 12 . Slots 11 are cut in the inward or lingual side of the adjacent teeth 10 and 12 , by the dentist using a drill or other appropriate tool. The protruding ends 9 of wires 6 extend into the slots 11 . After the prosthesis is completed and the dentist is completely satisfied with its shape and appearance, the slots 11 , containing the ends 9 , are filled with a resin 20 , fixing the ends 9 of wires 6 , securing the prosthesis in place.
[0022] As illustrated in FIG. 2 , the two body sections 2 and 3 which are preferably identical, can be moved apart from seam 4 along the wires 6 passing through the bores or channels 7 to accommodate such movement. This allows the dentist to adjust the width of the prosthesis body 1 to the exact width of the gap into which the prosthesis is to be installed.
[0023] FIGS. 3 is a side cross sectional view of the matrix 1 , showing the position of wire bores or channels 7 and pontic face apertures 5 .
[0024] As shown in FIG. 4 , after the body 1 has been adjusted to a proper fit, and the slots 11 formed and resin 20 has been applied, the pontic face 8 is applied to body 1 as shown in FIG. 4 . Pontic face 8 is uncured resin which is packed, extending into the apertures 5 and onto body 1 . The pontic face 8 extends over the top of body 1 and under the bottom of body 1 . The pontic face 8 is contoured and tinted by the dentist to match the adjacent teeth. After the resin of pontic face 8 is hardened, the prosthesis is removed and polished on all sides. This is particularly important as to that surface of the prosthesis which extends into the gum socket, so it does not irritate the gum.
[0025] In the preferred embodiment illustrated, the wires are hardened stainless steel of 28 gauge thickness. However, any suitably narrow and rigid wire or strip could be used.
[0026] It will be further apparent to those skilled in the art that various modifications and variations can be made in the device and method of the present invention without departing from the spirit or scope of the invention.
[0027] The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention should not be construed as limited to the particular embodiments which have been described above. Instead, the embodiments described here should be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the present invention as defined by the following claims:
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A dental prosthesis is described which includes two separable halves with three rigid wires extending through the halves and protruding beyond them and providing a resin to anchor the prosthesis to adjacent teeth.
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This invention was made with Government support under a contract awarded by the Department of the Air Force. The Government has certain rights in this invention.
FIELD OF THE INVENTION
The present invention relates to a joint for supporting a flap in an exhaust nozzle of a gas turbine engine.
BACKGROUND
Flow directing flaps in a gas turbine engine exhaust nozzle are subject to extremely harsh environmental conditions which have a significant impact on the design criteria of the overall flap arrangement and individual components. Exhaust gas temperatures may reach 4,000 F. or higher in the engine afterburning mode, requiring the use of temperature resistant materials and internal cooling to enable the gas contacting flap surfaces to withstand such temperatures for extended periods. The static gas pressure forces exerted on such flaps may range up to 50 psi (345 kPa) or greater depending upon the operational configuration of the nozzle and the current engine power output.
It is further desirable that such flaps be light in weight and easily disassembled for service or replacement. Disassembly is further complicated by the cramped clearances typically available within the nozzle for admitting workers, tools, etc.
In one design of a transversely extending flap in a thrust vectoring exhaust nozzle the flap is linked at the span ends to a pair of opposed sidewall disks which, under the influence of a positive internal static gas pressure, impart a resultant moment to the flap span ends for reducing the magnitude of the mid span flap deflection as fully explained in copending U.S. application Ser. No. 019,996 filed Feb. 27, 1987 by C. R. Stogner and W. M. Madden, titled "Exhaust Nozzle Flap Assembly". The combination of moment and shear forces at the span ends of such transversely oriented flaps results in a complicated pattern of stress at any joint located in such region, increasing the amount of reinforcing material, and hence weight, required to accommodate such forces as well as complicating the ducting of sufficient cooling gas into the flap interior.
What is needed is a simple, lightweight joint for securing an internally cooled flap in an exhaust nozzle of a gas turbine engine or the like.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a means for supporting a flow diverting flap in an exhaust nozzle of a gas turbine engine.
It is further an object of the present invention to provide a supporting means which includes a rigid flap joint disposed between a removable central portion of the flow diverting flap and a pair of spaced apart, supporting sidewall members.
It is further an object of the present invention to provide a flap joint having a relatively large internal flow area for conducting a flow of cooling gas from the interior of the sidewall member into the interior of the removable flap central portion.
It is still further an object of the present invention to locate the flap joint or joints at a point along the flap span coincident with the absence of any transverse bending moment therein.
According to the present invention, a strong, simple joint is provided between two spaced apart, supporting sidewall members and a removable, central flap portion of a transversely extending flow diverting flap. The flap is cantilevered between the sidewall members and is positioned thereby for diverting at least a portion of the flowing exhaust gas stream for nozzle thrust vectoring, reversing, area control, etc.
The joint between the flap portion and the corresponding sidewall member further includes two spaced apart, parallel sets of hinge-like lugs, alternating between the sidewall member and the removable central flap portion. Each set of alternating lugs is linked by an elongated pin passing through the aligned lugs similar to the hinge pin in an ordinary hinge. The spaced apart hinge-like connections provide a simple, inflexible link between the supporting sidewall members and the cantilevered central flap portion.
The flap joint according to the present invention further provides ample flow area in the spanwise direction for conducting a cooling gas, such as air, from the interior of the sidewall member into the interior of the removable central flap portion without compromising the structural integrity of the intermediate joint. The flap portion is easily released from the sidewall support by withdrawing the elongated pins from the lug sets and removing the now released flap portion from the nozzle. Reversing this procedure easily and quickly resecures the flap portion without the use of complicated fastening means, etc.
Another feature of the joint arrangement according to the present invention is the spanwise location of the individual joints at points of zero absolute bending moment in the assembled flap. For those flaps subject to positive static gas pressure at the surface thereof, it has been found advantageous to impart a counteracting moment at the span ends of the cantilevered flap to offset the moment resulting from the gas static pressure loading over the flap span. By locating the flap joints between the central portion and the sidewall members at span locations having zero resultant moment, the present invention reduces the magnitude and complexity of the forces on the individual joint components. By eliminating the bending forces in the joints, the present invention reduces the weight and size of the flap structure adjacent the joints, thereby permitting an even greater interior flow area for admitting cooling air into the flap interior. The spaced apart hinge-like connections of the present invention are well suited to withstand the remaining simple shear forces present at the zero moment span locations, achieving the reliable, simple, lightweight arrangement desired.
Both these and other objects and advantages of the joint arrangement according to the present invention will be apparent to those skilled in the art upon review of the following description and the appended claims and drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an isometric view of one of the sidewall members of the flap arrangement according to the present invention.
FIG. 2 shows a spanwise section of the assembled central flap portion and sidewall member according to the present invention.
FIG. 3 shows a graph of the magnitude of the transverse bending moment over the span of a flap having offsetting transverse moments imposed at the span ends thereof.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an isometric view of a sidewall member 10 which forms a portion of the lateral boundaries of a thrust vectoring 2-D exhaust nozzle for a gas turbine engine (not shown) or the like. The sidewall member 10 or disk, is rotatable about a pivot axis 12 for positioning a flow diverting flap, a stub portion of which 14 is shown in FIG. 1. The flap extends transversely across the flowing exhaust gas stream (not shown in FIG. 1) and may be selectably positioned to control the nozzle outlet area, exhaust gas flow direction, or both.
The flap contacts hot exhaust gases having temperatures in the range of 4,000 F., or higher. To protect the flap surface and internal structures from the high temperature environment, a cooling gas 16 such as air is admitted into the sidewall member 10 and conducted internally into the stub portion of the flap 14. It should be understood that the sidewall member 10 as shown in FIG. 1 is merely one-half of the supporting arrangement for the transversely extending flap which engages a similar but oppositely oriented sidewall member (not shown) in the opposite lateral nozzle flow boundary. The stub flaps 14 which extend from the sidewall members 10 engage a central, removable flap portion 18 as shown in FIG. 2. FIG. 2 gives further details as to the sidewall member 10 and the bearings 20 for permitting rotation about the pivot axis 12. The bearings 20 are disposed intermediate the sidewall member 10 and the nozzle static structure 22 for permitting rotation of the assembled flap while receiving a flow of cooling air 16 through a cooling air supply duct 24.
FIG. 2 shows a detailed cross sectional view of the flap joint 26 according to the present invention. Referring also to FIG. 1, the joint 26 is seen as a first plurality of lugs 28 alternatingly integral with the central flap portion 18 and the sidewall stub 14. A second plurality 30 of like alternating lugs is spaced apart from the first plurality 28. The two sets 28, 30 of lugs are secured by respective hinge pins 32, 34 which pass sequentially through each lug of the set.
The joint 26 according to the present invention is thus seen as two spaced apart hinge-like connections which form a strong, non-rotatable joint 26 between the sidewall member and stub 14, 10 and the central flap portion 18 of the flap assembly. FIG. 1 shows particularly those lugs 36, 38 of the respective sets 28, 30 which are part of the first sidewall member 10 and corresponding flap stub 14. It will be appreciated that the hinge-like connections 28, 32 and 30, 34, although parallel, are not aligned in the plane of the inward facing surface of the sidewall member 10. This facilitates removal of the central portion 18 of the flap following withdrawal of the elongated pins 32, 34 from the lug sets 28, 30. After such release, the central portion 18 may be lifted into the interior 42 of the nozzle and withdrawn without completely disassembling the sidewall support members and static structure.
As stated above, it is necessary to provide a flow of cooling gas such as relatively cool compressed air furnished from the compressor section of the gas turbine engine (not shown) via the cooling air duct 24. Such flow passes internally through the sidewall member 10 and the integral stub flap 14, entering the central portion 18 of the flap through the flap joint 26. The use of the spaced apart hinge-like connections 28, 32 and 30, 34 of the joint 26 according to the present invention provides a significant free flow area 40 for passing such cooling air between the stub flap 14 and the central portion 18. The cooling air 16 entering the central portion 18 is directed therewithin to internally cool the central portion surface and may be exhausted into the exhaust gas stream or conducted into adjacent structures by any of a plurality of means and methods well known in the art, such as flexible joints, transpiration cooling openings, etc.
An additional feature of the flap joint according to the present invention involves the spanwise location of the joint 26. For exhaust nozzles having a positive internal gas static pressure, it will be apparent to those skilled in the art that those surfaces of the sidewall members 10 and central flap portion 18 facing the nozzle interior 42 will be subject to significant outward forces resulting from the distributed gas static pressure loading. As discussed in copending application Ser. No. 019,996, referenced hereinabove, an integral sidewall member and cantilevered flap arrangement as shown in FIG. 2 will experience reduced mid span flap deflection by causing the sidewall members 10 to impart a resultant negative moment at the span ends of the flap 14, 18 to counteract the positive moment induced by the gas static pressure loading. FIG. 3 shows the variation of transverse moment over the length L of the flap span. The zero span displacement point is adjacent one of the opposing sidewall members 10 while the L span displacement represents the other span end of the flap adjacent the other sidewall member.
As will be appreciated by those skilled in the art, the negative moments 44, 45 imposed by the sidewall members at each span end of the cantilevered flap reduce the overall magnitude of the mid span, L/2, moment 46 and hence the corresponding mid span elastic displacement. This distribution also results in two loci of null moment 48, 50 located intermediate the flap mid span L/2 and the span ends zero, L.
It is a feature of the joint arrangement according to the present invention that the joints 26 between the central flap portion 18 and the stub flaps 14 are located coincident with the null moment loci 48, 50. As a result of such placement, the joints 26 are subject to only shear force loading and are thus not required nor reinforced to withstand transverse bending moments or like forces. The resulting simplicity of the forces supported at the joints 26 reduces the structural reinforcement required to support the central flap portion 18 thus increasing the flow area 40 available to admit cooling air into the central flap portion as well as decreasing the overall and local weight of the joint 26 and assembled flap 14, 18.
The flap arrangement according to the present invention is thus seen as a lightweight, simple structure for securing and supporting the transverse, flow directing flap in a thrust vectoring nozzle for a gas turbine engine. The joint arrangement further provides for the easy removal and replacement of the central flap portion 18 without disassembly and consequent disruption of the sidewall members 10 and the associated bearing and static structure 20, 22. By locating the joints 26 at a locus of null moment along the flap span, the present invention minimizes the magnitude and complexity of the forces exerted on the individual joint components further reducing the weight and maximizing the flow area 40 available for admitting cooling air from the sidewall member interior into the interior of the central flap portion 18.
It will further be appreciated that the foregoing description and illustrated embodiment is intended to illustrate only one flap support arrangement according to the present invention and should thus not be interpreted as implying any limitations thereto except as specifically recited in the following claims.
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A transverse pivotable flap is cantilevered between movable sidewall members (10) which include a stub flap (14). A removable central flap portion (18) is secured between the stub flats (10) by a pair of joints (26) having alternating lug sets 28, 30, secured by respective elongated pins (32, 34). Flow area (40) is provided to conduct internal cooling air (16) into the central flap portion (18).
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BACKGROUND OF THE INVENTION
Calcium carbonate is used extensively in the paper industry as a filler component in paper. It is a low cost, high brightness filler used to increase sheet brightness and opacity, Its use has increased dramatically in recent years due to the conversion from acid to alkaline papermaking at many paper mills. Both natural and synthetic calcium carbonates are used in the paper industry. Natural calcium carbonate, or limestone, is ground to a small particle size prior to its use in paper, while synthetic calcium carbonate is manufactured by a precipitation reaction and is called precipitated calcium carbonate (PCC). PCC is typically superior in opacifying and brightening the sheet, as compared to ground calcium carbonate.
The primary method for manufacturing PCC for the paper industry is the carbonation process. In this process, carbon dioxide is bubbled through a slurry of calcium hydroxide to produce PCC. Numerous plants using this process have been installed at paper mill sites, using boiler or kiln flue gas as a source of carbon dioxide. This process has demonstrated the capability to produce PCC with superior opacifying characteristics. Scalenohedral-shaped precipitated calcium carbonate with a rosette-like aggregate structure has been found to impart high sheet opacity and is the predominant product manufactured at these on-site PCC plants. This aggregate rosette structure reduces particle-particle packing and maximizes the PCC-air interfacial area in the sheet, thereby achieving higher opacity. The aggregate rosette structure is also known to increase the bulk of paper in which it is used. The carbonation process has also shown flexibility in producing various particle shapes and sizes for various applications as both a paper filler and in paper coatings.
The soda lime process is another method for manufacturing PCC. Sodium carbonate solution is added to calcium hydroxide slurry to react and produce PCC and sodium hydroxide. This process has the advantage of producing sodium hydroxide as a co-product, which is used in many paper mills. The Kraft pulping cycle uses this reaction in converting green liquor to white liquor. However, the PCC produced in this way is usually not suited as a paper filler due to its larger particle size. Reaction conditions for this application are chosen to maximize sodium hydroxide production, and these conditions typically produce a coarser PCC. Although the soda lime process has been considered for commercial production of PCC for use as a paper filler, no such plants are currently known to exist. Consistent production of a small particle size PCC with good opacifying ability has not been demonstrated yet in the soda lime process. The scalenohedral-shaped PCC with a rosette-like aggregate structure that is produced by the carbonation process and known to impart high opacity has not heretofore been achieved with the soda lime process.
SUMMARY OF THE INVENTION
An object of the present invention is to produce PCC with the soda lime process that has an opacifying ability similar to the high opacity PCC fillers currently produced using the carbonation process.
Another object of the invention is to produce scalenohedral shaped PCC particles that are aggregated together into rosette-like aggregates.
Another objective of the invention is to demonstrate that the size of the PCC particles produced can be controlled.
Another object is to provide by the soda lime process PCC that increases the bulk of paper.
Generally speaking, in practicing this invention sodium carbonate solution is added to calcium hydroxide slurry in a stirred constant-temperature reactor over a specified duration of time as a batch operation. The calcium hydroxide slurry is prepared by adding high-calcium quicklime to water, which is known as slaking. The slurry produced from the reaction of sodium carbonate and calcium hydroxide is filtered to separate the PCC wetcake from the filtrate, which contains sodium hydroxide and residual sodium carbonate. The PCC wetcake is washed to remove residual sodium hydroxide and sodium carbonate and is then reslurried in water. Carbon dioxide gas is then bubbled through the PCC slurry to convert any residual calcium hydroxide into PCC.
It has been found that the soda lime process according to this invention can produce a scalenohedral-shaped PCC with a rosette-like aggregate structure similar to that produced with the carbonation process. The PCC produced from the soda lime process of this invention has the same high opacifying ability as PCC produced from the carbonation process. The critical parameters for achieving the proper PCC structure (i.e. scalenohedral-shaped with rosette-like aggregate structure) and high opacity with the soda lime process have been found to be: (1) reaction temperature, (2) sodium carbonate addition time, (3) sodium carbonate addition method, and (4) type of agitation. Variation of the size of the PCC particles pursuant to this invention has been demonstrated through proper manipulation of the above four parameters. Precipitated calcium carbonate having scalenohedral particle shape, a rosette aggregate structure produced by this invention have scattering coefficients at least as great as 2700 cm 2 /g and preferably as great as 2900 cm 2 /g.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing:
FIG. 1 is a photomicrograph at a magnification of 10,000 showing surface views of scalenohedral-shaped PCC having a rosette aggregate structure made according to this invention by the process described in Example 3; and
FIG. 2 is a photomicrograph at a magnification of 10,000 showing surface views of the scalenohedral PCC particles having no rosette structure made by the process of Example A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The proper PCC structure, i.e., scalenohedral shaped particles having a rosette aggregate structure, and particle size pursuant to this invention are obtained at a reaction temperature ranging from 80° to 140° F., preferably 90° to 110° F. This temperature range contrasts dramatically from that used to convert green liquor to white liquor in the Kraft pulping cycle, where reaction temperatures are normally kept above 180° F. Higher temperatures are used to increase production since the reaction rate and conversion also increases with temperature for the soda lime reaction.
The proper PCC structure and particle size are obtained by this invention when the batch addition time for the sodium carbonate solution ranges from 1 to 8 hours. These sodium carbonate addition times are unique since the soda lime reaction can achieve near complete conversion in less than 30 minutes. Although the increased sodium carbonate addition times reduce the production capability, this unique approach enables the proper PCC structure to be achieved.
The proper PCC structure and particle size are obtained pursuant to this invention when the sodium carbonate solution is simultaneously added to the calcium hydroxide slurry in more than one stream, preferably many separate small streams, instead of one large single stream. Preferably at least nine streams are used. The stream size and flow rate in each stream may need to be reduced and the number of streams increased in order to achieve the proper PCC structure and particle size. For larger reaction vessels, i.e., as the quantity of calcium hydroxide reactant is increased, a greater number of sodium carbonate streams can be used to produce the proper PCC structure and particle size. Although distributed addition of a reactant solution is not unusual in general practice, it is believed that this approach is unique for the soda lime reaction in conjunction with the above-mentioned temperature and addition time constraints.
An axial-flow type impeller is preferred to provide uniform mixing by causing the reaction mass to flow down the impeller shaft and up the sides of the reaction vessel.
Stoichiometric ratios can be used for the soda lime reaction. A slight excess of sodium carbonate (up to 10%, molar basis) is desirable to maximize the conversion of the reaction and thereby minimize the amount of residual calcium hydroxide in the products.
Maximizing the concentrations of sodium carbonate and calcium hydroxide is desirable since this results in an increase in the strength of the caustic filtrate co-product making it more readily usable in subsequent processing in the paper mill. In general, sodium carbonate concentrations used are slightly less than the solubility limit at the reaction temperatures. Calcium hydroxide concentrations below 15 weight % are desirable to prevent the slurry mixture from gelling during the reaction. Gelling of the reaction slurry is not desirable since it impedes the mixing of the slurry during the reaction.
Calcium hydroxide slurry reactant is prepared by slaking lime in water. The lime must have a high calcium oxide content (>90 weight %) and preferably has a high reactivity in water. Reactivity is determined in the laboratory by measuring the temperature rise that occurs in 30 seconds after a lime sample is added to water at a lime to water ratio of 4 to 1. A temperature rise of at least 30° C. is preferred.
The following examples are presented. In each example an axial-flow type impeller was used.
EXAMPLE 1
This Example shows that the soda lime reaction can produce a scalenohedral-shaped PCC with a rosette-like aggregate structure and a high opacifying ability similar to that produced using the carbonation process. In this example, aqueous sodium carbonate solution (1400 cc, 316 g/l) was gradually added at a constant rate in 9 streams to an agitated 6 liter reactor containing aqueous calcium hydroxide slurry (2100 cc, 134 g/l). The total addition time for the sodium carbonate solution was 2.2 hours. The sodium carbonate solution and the contents of the reactor were maintained at a constant temperature of 100° F. throughout the reaction. The reaction mixture was agitated at this temperature for 20 minutes after completion of sodium carbonate addition and the resulting slurry was filtered to form a PCC wet cake which was then washed with water to remove residual NaOH. The washed wet cake was then reslurried in water to form a slurry through which CO 2 was bubbled to convert any residual calcium hydroxide into PCC. The resulting PCC slurry was ready for use in making or coating paper.
The resulting PCC was then tested to determine its opacifying ability, particle size, and particle structure. The scattering coefficient of the PCC is a measure of its opacifying ability and was determined from handsheets prepared with PCC. The average particle size was determined using a Model 5100 Micromeritics Sedigraph particle size analyzer, which estimates the particle size based on the settling rate of the particles. The particle structure was determined from photographs taken with a scanning electron microscope at a magnification of 10,000 times the actual size. For comparison. PCC that had been prepared by the carbonation process using the same batch of calcium hydroxide slurry was tested. The properties of the soda lime PCC, made pursuant to this invention, and the carbonation PCC are shown in Table 1 below.
TABLE 1______________________________________Property Soda Lime PPC Carbonation PCC______________________________________Scattering Coefficient, cm.sup.2 /g 2800 2900Average Particle Size, 1.2 1.3micronsParticle Shape scalenohedral scalenohedralAggregate Structure rosette rosette______________________________________
These results show that the properties of the soda lime PCC made pursuant to Example 1 and the carbonation PCC are very similar.
EXAMPLE 2
This Example refers to work on a pilot scale and shows that the soda lime reaction carried out pursuant to this invention can produce a scalenohedral-shaped PCC with a rosette-like aggregate structure and a high opacifying ability similar to that produced using the carbonation process. In this example, sodium carbonate solution (132 liters, 316 g/l) was gradually added in 33 streams at a constant rate to an agitated 100 gallon reactor containing calcium hydroxide slurry (196 liters, 135 g/l). The total addition time for the sodium carbonate solution was 3.2 hours. The sodium carbonate solution and the contents of the reactor were maintained at a constant temperature of 100° F. throughout the reaction. The reaction mixture was agitated at this temperature for 15 minutes after completion of sodium carbonate addition and the resulting slurry was filtered to form a PCC wet cake which was then washed with water to remove residual NaOH. The washed wet cake was then reslurried in water to form a slurry through which CO 2 was bubbled to convert any residual calcium hydroxide into PCC. The resulting PCC slurry was ready for use in making or coating paper. The resulting PCC produced was tested in the same manner as described in Example 1. As was done in Example 1, a corresponding PCC produced by the carbonation process was also tested. The test results are shown in Table 2 below.
TABLE 2______________________________________Property Soda Lime PPC Carbonation PCC______________________________________Scattering Coefficient, cm.sup.2 /g 2900 2900Average Particle Size, 1.5 1.4micronsParticle Shape scalenohedral scalenohedralAggregate Structure rosette rosette______________________________________
These results show that the properties of the soda lime PCC made pursuant to this Example were substantially the same as PCC made by the carbonation process.
EXAMPLE 3
This Example illustrates work on a commercial scale and shows that the soda lime reaction can produce a scalenohedral-shaped PCC with a rosette-like aggregate structure and a high opacifying ability similar to that produced using the carbonation process. In this Example, aqueous sodium carbonate solution (3700 gals, 2.61 #/gal.) was gradually added in 160 streams at a constant rate to an agitated 10,000 gallon reactor containing calcium hydroxide slurry (5500 gals., 1.11 #/gal). The total addition time for the sodium carbonate solution was 4.4 hours. The sodium carbonate solution and the contents of the reactor were maintained at a constant temperature of 95° F. throughout the reaction. The reaction mixture was agitated at this temperature for 40 minutes after completion of sodium carbonate addition and samples of the resulting slurry were filtered to form a PCC wet cake which was then washed with water to remove residual NaOH. The washed wet cake was then reslurried in water to form a slurry through which CO 2 was bubbled to convert any residual calcium hydroxide into PCC. The resulting PCC slurry was ready for use in making or coating paper. The resulting PCC produced was tested in the same manner as described in Example 1. As was done in Example 1, the corresponding PCC produced by the carbonation process was also tested. The test results are shown in Table 3.
TABLE 3______________________________________Property Soda Lime PPC Carbonation PCC______________________________________Scattering Coefficient, cm.sup.2 /g 2700 3000Average Particle Size, 1.8 1.3micronsParticle Shape scalenohedral scalenohedralAggregate Structure rosette rosette______________________________________
These results show that these properties of the soda lime PCC made pursuant to Example 3 were substantially equivalent to PCC made by the carbonation process.
EXAMPLE A, B and C
For comparison, Examples A, B and C are given in which the critical process parameters of reaction temperature and sodium carbonate addition time were not within the optimum ranges. Examples A, B and C do not illustrate the invention. In Examples A and C, aqueous sodium carbonate solution (1410 cc, 312 g/l) was added in 9 streams at a constant rate to an agitated 6 liter reactor containing calcium hydroxide slurry (2110 cc, 133 g/l). In Example B, aqueous sodium carbonate solution (1400 cc, 317 g/l) was added in 9 streams at a constant rate to an agitated 6 liter reactor containing calcium hydroxide slurry (2100 cc, 135 g/l). The total addition time for the sodium carbonate solution for each Example is given in Table 4 below. The sodium carbonate solution and the contents of the reactor were maintained at the constant temperature given in Table 4 for each Example throughout the reaction. The resulting PCC produced was tested in the same manner as described in Example 1. As was done in Example 1, the corresponding PCC produced by the carbonation process was also tested and showed a scattering coefficient cm 2 /g of 2900, an average particle size of 1.3 microns, a scalenohedral particle shape and a rosette aggregate structure.
The process conditions for each Example and the properties of the PCC produced by each Example are summarized in Table 4.
TABLE 4__________________________________________________________________________SUMMARY OF EXAMPLESEXAMPLE NUMBER: 1 2 3 A B C__________________________________________________________________________REACTION CONDITIONSReaction Temperature, F. 100 100 95 150 90 150Sodium Carbonate Addition Time, hours 2.2 3.2 4.4 0.25 0.25 1.25Reactor Size, gallons 1.6 100 10000 1.6 1.6 1.6Agitation Speed, rpm 2250 420 125 2250 2250 2250Impeller Diameter, inches 2.5 11.8 58 2.5 2.5 2.5PCC PROPERTIESScattering Coefficient, square cm/g 2800 2900 2700 2200 1900 1800Average Particle Size, microns (1) 1.2 1.5 1.8 1.7 1.7 2.2Average Individual Particle Length, 1.2 1.1 1.7 2.6 0.3 3.8microns (2)Particle Shape scalenohedral scalenohedral scalenohedral scalenohedral small scalenohedral scalenohedralAggregate Structure rosette rosette rosette individual random individual particles (3) clusters particles__________________________________________________________________________ (3) NOTES: (1) Measured by Micromeritics model 5100 SediGraph. (2) Estimated from scanning electron microscope photographs. (3) No rosettelike aggregate structure.
The opacifying abilities of the soda lime PCC produced in Examples A, B and C were significantly lower than the PCC produced in Examples 1-3, as indicated by a 25% or more reduction in the scattering coefficient. In addition, the resulting PCC's of Examples A, B and C were predominantly individual scalenohedral particles with only a few aggregates or were random clusters.
It is evident from Examples 1-3 that the soda lime reaction as practiced pursuant to this invention can produce a scalenohedral-shaped PCC with a rosette-like aggregate structure and a high opacifying ability similar to that produced using the carbonation process.
It will be understood that while the invention has been described in terms of and with the aid of many illustrative examples, numerous changes in details, proportions, ingredients, and the like may be made within the broad scope of the invention, as defined by the claims which follow.
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In the process for making calcium carbonate by the double decomposition reaction of sodium carbonate and calcium hydroxide in aqueous reaction medium the improvement of producing calcium carbonate having a scalenohedral particle shape and a rosette aggregate structure comprising adding said sodium carbonate in more than one stream to said calcium hydroxide over a period of 1 to 8 hours and maintaining said reaction medium in the range of 80° to 140° F.
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This is a division of application Ser. No. 746,723, filed Dec. 2, 1976, U.S. Pat. No. 4,229,554.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to antistatic additives for textile fibers, particularly for polyamide fibers, which have reduced flammability as compared to prior art antistatic additives.
2. Description of the Prior Art
It is known to obtain decreased buildup of static electricity charge induced by friction on the surface of synthetic textile materials by the incorporation of antistatic additives at the melt-spinning stage of synthetic fiber production. Water-soluble antistatic additives are disclosed in U.S. Pat. No. 3,475,898 which are the poly(alkylene ether) type polymer. Nylon fibers are improved by the incorporation of said water-soluble polymers which, upon the scouring of textile fabrics made using the modified polyamide fibers so treated, are at least partially removed so as to leave voids in the polyamide polymer which remain where the polyether has been removed.
Antistatic polyamide fibers have also been disclosed in U.S. Pat. No. 3,657,386 and U.S. Pat. No. 3,794,631 in which the antistatic additive is based upon a high molecular weight propylene oxide ethylene oxide copolymer based upon ethylenediamine, either alone or containing as an additional component a fatty acid salt.
Both of the above types of antistatic additives have the disadvantage of being more highly flammable than the polyamide fiber itself and, therefore, the incorporation of such antistatic additives increases the flammability of a nylon fiber. Such undesirable increases in flammability of such antistatic polyamide fibers have been a disadvantage which threatens the continued use of such antistatic additives. It is therefore an object of this invention to provide an antistatic additive which does not contribute to the flammability of a polyamide fiber and, therefore, can be used in a sufficient amount to provide maximum antistatic properties without, at the same time, conferring upon the polyamide fiber increased flammability.
The invention has particular application in the manufacture of a carpet, the face of which is made from fibrous textile material which in use normally tends to accumulate a charge of static electricity.
It is known to impart flame retardancy to a synthetic material by incorporating a flame-retarding agent whereby the flame-retarding agent is made an integral part of the chemical structure of the synthetic material. In U.S. Pat. No. 3,883,611 there is disclosed the use of dibromopentaerythritol incorporated into the chemical structure of a polyester to impart flame retardancy. A block copolyester of poly(ethylene terephthalate/tetramethylene dibromoterephthalate) is disclosed as a means of providing flame retardancy to poly(ethylene terephthalate) which overcomes the undesirable thermally unstable characteristics of such compounds as dibromopentaerythritol.
Recently, a polyester prepolymer of a brominated diol has been disclosed which is prepared by the ethoxylation of 4,4'-isopropylidine(2,6-dibromophenol), commonly referred to as tetrabromobisphenol A. Such prepolymers are disclosed in U.S. Pat. No. 3,794,617 and are said to be particularly useful reactive intermediates for the preparation of fiber-forming copolyesters since the prepolymers of the brominated diol have excellent heat stability and thus show little or no discoloration upon exposure to the high temperatures utilized in the preparation and melt-spinning of polyester fibers. In U.S. Pat. No. 3,909,482 there is also disclosed a process for the production of flame-retardant polyester filaments based upon similar halogenated compounds.
The simplest means of incorporating a flame-retardant chemical to provide resistance to burning has been by a surface treatment of the dyed fabric with one or more flame-retardant additives. Surface treatment of the fabric usually has only a temporary effect and the flame-retardant additive is rapidly lost when the fabric is laundered or drycleaned. As discussed above, relatively permanent flame-retardant effects have been obtained by copolymerizing the halogenated flame-retardant monomers of U.S. Pat. No. 3,883,611 into the polymer structure to obtain reduced burning characteristics or physically mixing such halogenated additives into the polymer. The physical mixtures often detract from the physical properties of the base polymer so that while the flame-retardant effect may be relatively permanent, the fibers may be more brittle or have lower tensile strength or less resistance to oxidative degradation or show reduced color stability.
Halogenated additives which have been incorporated into polymeric materials to render them flame-retardant can include either chlorinated or brominated compounds. It is recognized that brominated compounds are often more effective flame retardants than the corresponding chlorinated materials and that synergistic improvements can be obtained by admixture therewith of certain compounds such as antimony oxide. However, brominated materials have often been limited to applications not involving the use of high temperatures since brominated materials tend to decompose and impart undesirable discoloration to the compositions to which they have been incorporated. With many known brominated compounds having hydroxyl or carboxyl groups the objectionable discoloration is so pronounced at polymerization temperatures that the physical properties of the polymer are adversely affected. Such considerations are important in a flame-retardant antistatic additive which is to be incorporated, for instance, into the polyamide fiber by admixture into the polyamide melt prior to the spinning operation.
SUMMARY OF THE INVENTION
The applicants have discovered a new flame-retardant polymeric antistatic additive for synthetic polymeric fibers which is useful both (1) as a polymer composition which can be incorporated in the amount of about 1 percent to about 12 percent by weight of the fibers into the polymer melt prior to spinning of the fiber, or (2) as a surface coating for application to a polyamide, polyester, polyolefin, polyurea, polyurethane, polysulfonamide or polyacrylic fiber subsequent to the weaving and dyeing operation. When the flame-retardant antistatic additive is used as a coating on the surface of the fiber subsequent to the weaving and dyeing operation, it has been found to provide a lubricating or softening effect which promotes a more desirable "hand" to the woven material without contributing to the flammability of the fiber.
The compositions of the invention which provide antistatic properties without the additional tendency toward flammability in the polyamide fiber (which is characteristic of the antistatic additives of the prior art) comprise the reaction product of:
(a) a polyoxyalkylene compound or polyester thereof and
(b) at least one reactant selected from the group consisting of (1) a diol, (2) a polyester and (3) an aliphatic or aromatic diacid or derivative of (3), wherein at least one reactant is halogenated.
The polyoxyalkylene compound can consist of monomeric units, which are the same or different, and where different units can be obtained by block polymerization or from heteric or random polymerization.
The flame-retardant antistatic polymer of the invention can be used either alone or in combination with an effective flame-retardant proportion of a metallic oxide of a metal from group Vb of the periodic table, i.e., phosphorus, arsenic, antimony, or bismuth. The preferred embodiment is antimony trioxide.
Where the flame-retardant antistatic additive of the invention is applied as a coating to the polyamide fibers of a dyed and woven textile fabric, any inert solvent having the capacity to dissolve or disperse an effective amount of the polymer compound of the invention can be used as a means of providing an even distribution of the polymeric compound on the surface of the fiber. A mixture of water and isopropanol containing a small amount of surfactant is preferred for this use. A solvent such as an aliphatic or aromatic hydrocarbon or the chlorinated derivatives thereof can also be used.
DETAILED DESCRIPTION OF THE INVENTION
Suitable antistatic properties can be imparted to a shaped article such as a synthetic polymer filament, yarn or the like, i.e., a synthetic linear fiber-forming polyamide, by incorporation of about 1 percent to about 12 percent of the flame-retardant polymer additive of the invention into the melt prior to melt-spinning fibers from synthetic polymer. Permanent antistatic effects are thus obtained without the concomitant increase in susceptibility to flammability that is characteristic of the antistatic additives of the prior art. Where about 0.1 percent to about 12 percent additive of the invention is coated onto the fibers of a synthetic polymer, preferably about 2 percent to about 6 percent a softening as well as an antistatic effect is obtained. The polyamides are well known in the art and are in general formed by heating an aqueous solution of the salt of a diamine and a dicarboxylic acid or by polymerization of a lactam. Representative polyamides include polyhexamethylene adipamide, polyhexamethylene sebacamide, polyhexamethylene terephthalamide and polycaprolactam.
THE CONJUGATED POLYOXYALKYLENE COMPOUND
As a component of the polymeric flame-retardant antistatic additive of the invention, there is used a conjugated polyoxyalkylene compound, or polyester thereof, said compound consisting of oxypropylene and oxyethylene groups and having as a nucleus, a nitrogen containing reactive hydrogen-containing compound having up to 6 carbon atoms per molecule and selected from the group consisting of ammonia, primary alkyl amines, alkylene polyamines, alkanolamines and heterocyclic nitrogen compounds. Useful primary alkyl amines having not over 6 carbon atoms are methylamine, ethylamine, propylamine, butylamine, amylamine, aniline and hexylamine. Useful alkylene polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, phenylenediamine and the like. Alkanolamines having not over 6 carbon atoms can be used such as monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, tri(2-propanol)amine, 2-amino-1-butanol, N-butyl-di(2-propanol)amine and the like. Furthermore, heterocyclic nitrogen compounds containing a hetero N atom can be employed, such as piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, imidazimidazole, pyrazolidine, pyrazolidone, hydantoin, dimethylhydantoin and the like. Hydroxylamine and the hydroxylamine derivatives and aminophenol and aminophenol derivatives can also be used.
The conjugated polyoxyalkylene compounds can be block polymers, i.e., either all of the oxypropylene groups or all of the oxyethylene groups present are attached to the reactive hydrogen-containing nucleus compound at the sites of the reactive hydrogen atoms, with the alternate groups (either oxyethylene or oxypropylene), being present on the chain attached to the ends of the oxyethylene or oxypropylene chains previously described as attached to the nucleus compound at the sites of the reactive hydrogen. Heteric polymers containing random groupings of oxyethylene and oxypropylene can also comprise the conjugated polyoxyalkylene compound. The average molecular weight of the oxypropylene chains can be at least about 900 to about 25,000 and the oxyethylene groups can be in an amount so as to constitute from 20 to 90 weight percent of the mixture in the compound.
The preferred conjugated polyoxyalkylene compound is based upon ethylenediamine as the nucleus nitrogen containing reactive hydrogen compound. Where a polyester of said polyoxyalkylene compound is used, this is the reaction product of said compound with an aromatic, aliphatic dicarboxylic acid or corresponding acid anhydride, ester or acid halide. The conjugated polyoxyalkylene compounds are known as antistatic additives for polyamine compositions, particularly for filaments or yarns prepared by melt-spinning a combination of the antistatic additive and the linear film-forming polyamide. Such conjugated polyoxyalkylene compounds, known as tetrol compounds, are commercially available.
Useful polyester reactants of said tetrol compounds can be prepared by reacting with said tetrol a substantially equivalent amount of an aliphatic or aromatic diacid, acid anhydride or other derivative thereof in a conventional esterification reaction. The diacid, anhydride or other derivative thereof can be halogenated or non-halogenated.
REACTANTS FOR PRODUCING THE ANTISTATIC POLYMER ADDITIVE
The flame-retardant antistatic polymer additives of the invention are derived from the reaction of a conjugated polyoxyalkylene compound, i.e., a tetrol, or polyester thereof with at least one reactant as previously defined above. Said reactant can be a halogenated diol.
1. Diols
Examples of useful halogenated diols are as follows: alkoxylated tetrabromobisphenol A, alkoxylated tetrabromohydroquinone, alkoxylated tetrabromoresorcinol, 3-pentachlorophenoxy-1,2-propanediol, alkoxylated tetrachlorobisphenol A, alkoxylated tetrachlorohydroquinone, alkoxylated tetrachlororesorcinol, 2,2-bis(bromomethyl)-1,3-propanediol, alkoxylated octachloro-4,4'-bis-hydroxybiphenyl, alkoxylated octachloro-4,4'-bis-aminobisphenyl, and 2,2-bis(chloromethyl)-1,3-propanediol.
Preferred brominated diols are those obtained by alkoxylation of a diol, such as brominated bisphenol A, with an alkylene oxide. Especially useful brominated diols are obtained by reaction of a brominated diol with ethylene oxide, propylene oxide and mixtures thereof. Preferably, the bromine is substituted in the positions ortho to the site of alkoxylation, i.e., in the 2- and 6-ring positions of a compound such as tetrabromobisphenol A.
The brominated diols are prepared using known reaction techniques. For example, 2,2-bis[3,5-dibromo-4-(2-hydroxyethoxy)phenyl] propane is obtained by the ethoxylation of 4,4'-isopropylidene-(2,6-dibromophenol), commonly referred to as tetrabromobisphenol A. The tetrabromobisphenol A (melting point 181°-182° C.) can be prepared by the direct bromination of bisphenol A or obtained commercially. The alkoxylation procedure generally consists of reacting the phenolic compound with the appropriate amount of alkylene oxide in the presence of a basic catalyst. The reaction can be conducted with or without a solvent, however, for the ethoxylation of tetrabromobisphenol A, a solvent is usually preferred. Known basic catalysts such as amines and alkali metal hydroxides can be employed. Triethylenediamine is useful and gives rapid reaction rates. Sodium hydroxide is also used where longer reaction times are not objectionable.
Typically, the tetrabromobisphenol A is dissolved in a hydrocarbon solvent, such as xylene, and charged to the reactor with the catalyst. Catalyst amounts can be varied widely but generally will be present in amounts between about 0.05 percent and 0.2 percent by weight based on the tetrabromobisphenol A. The reaction mixture can be distilled to azeotropically remove any water from the system or water which may have been introduced with the catalyst or is present in the solvent. Suitable proportions are at least 2 moles of ethylene oxide to 1 mole of tetrabromobisphenol A. The mixture is heated to 150° C., vented to 10 psig. and the ethylene oxide carefully fed into the reactor. Higher proportions of ethylene oxide or alternatively propylene oxide may be charged, however, if different alkoxylates are desired. Reaction temperature and pressure are maintained until the reaction is completed. Reaction conditions can be varied depending on the catalyst used and the rate of reaction desired. For example, reaction temperatures can be from about 110° C. to about 170° C. or higher while pressures can be from about 25 psig. up to about 75 psig. or higher. The reaction can be monitored by determining the amount of unreacted phenol in the reaction mixture. This is conveniently accomplished by titrating samples of the reaction mixture with a standardized base solution using phenolphthalein as an indicator. If desired, the reaction mixture can be treated with activated charcoal or the product may be directly recrystallized from solution by cooling to about 20° C. with rapid agitation. The brominated diol crystals are recovered by filtration and after washing with xylene may be used, as such, after air-drying in an oven. Alternatively, the solvent may be removed under vacuum at a temperature above the melting point of the product. Chips or flakes may be obtained by such treatment. The product obtained has a phenolic hydroxyl number of 26. Typical products are in the range of about 2 to about 30 phenolic hydroxyl.
2. Polyesters and Aliphatic and Aromatic Diacids and Derivatives
The flame-retardant polymers of the invention can also be prepared by the reaction of said conjugated polyoxyalkylene compound, i.e., tetrol or polyester thereof with a halogenated aliphatic or aromatic dicarboxylic acid or corresponding acid anhydride, ester or acid halide derivative thereof or a halogenated polyester reactant derived from the reaction of an aliphatic or aromatic diacid, anhydride or other derivative thereof and a diol, wherein either or both (1) the diacid or anhydride or (2) the diol is halogenated. As will be apparent to one skilled in the art, should said polyester of a tetrol be hydroxyl-terminated, said halogenated polyester must be carboxyl-terminated for reaction to occur, or vice versa. Should both polyesters be hydroxyl-terminated, reaction is obtained through a cross-linking agent. For substantially complete cross-linking of polyesters having both carboxylic acid and hydroxyl termination, a diacid is desirable as a cross-linking agent. Such cross-linking agents are selected from the group consisting of halogenated or non-halogenated aliphatic or aromatic diacids, anhydrides, esters or acid halides and mixtures thereof. Examples of useful halogenated diacids or anhydride derivatives thereof are as follows: tetrabromophthalic acid or anhydride, tetrachlorophthalic acid or anhydride, chlorendic anhydride (1,4,5,6,7,7-hexachlorobicyclo-(2.2.1.)- 5-heptene-2,3-dicarboxylic anhydride), brominated terephthalic acids such as 2,5-dibromoterephthalic acid, hexachlorooctahydro-5,8-methanonaphthalene-2,3-dicarboxylic acid or anhydride. Examples of useful non-halogenated, aromatic and aliphatic diacids and anhydrides are as follows: phthalic acid and phthalic anhydride, isophthalic acid, terephthalic acid and anhydride, azelaic acid, sebacic acid, adipic acid, maleic acid and anhydride.
Known reaction techniques are employed in preparing these halogenated polyester reactants. As described above, the halogenated diols can be used to prepare the halogenated polyester reactant. Useful non-halogenated diols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, glycerol, and pentaerythritol can also be used where at least one halogenated diacid, anhydride or derivative thereof is used. The polyesterification generally consists of reacting the aliphatic or aromatic diacid or anhydride with a substantially equivalent amount of a diol. The reaction can be conducted with or without a solvent, however, for the esterification of tetrabromophthalic anhydride with ethylene glycol, a solvent is usually not required. Known catalysts such as calcium acetate dihydrate and antimony trioxide can be employed.
The brominated or chlorinated polyester reactants of the invention generally contain about 30 to about 70 weight percent bromine or chlorine, have a hydroxyl value of about 5 to 40 and an acid value of less than 40, preferably less than 20 and generally contain approximately 10 percent of the diol residue.
As will be understood by persons skilled in the art, mixtures of non-halogenated diacids such as azelaic acid can be used to produce the polyester of the invention by combination with halogenated diacids or anhydrides in the esterification reaction with a diol to produce the halogenated polyester reactant of the invention. In addition, diacids or their anhydride derivatives can be reacted with halogenated diols to produce the halogenated polyester reactant of the invention.
The halogenated polyester described above is attached to the chain extended tetrol so as to provide about 5 to about 25 repeating polyester units on the tetrol. A total weight percent of halogen of about 5 percent to about 30 percent of the total weight of the flame-retardant polymeric additive is thus obtained. The polyester groups are present in an amount so as to constitute about 10 to about 60 weight percent of the flame-retardant antistatic polymer additive of the invention.
Examples of useful halogenated diacids, anhydrides, and derivatives thereof are those provided hereinabove. Both halogenated and non-halogenated diacids and anhydrides can be utilized as a means of cross-linking the reaction product of the polyoxyalkylene compound or polyester thereof and the halogenated reactant. As will be apparent to one skilled in the art, the corresponding lower alkyl (C 2 to C 8 ) esters and corresponding acid halides of said diacids and anhydrides can also be used.
Examples of useful dicarboxylic acids include the following: oxalic, malonic, dimethylmalonic, succinic, glutaric, adipic, trimethyladipic, pimelic, 2,2-dimethylglutaric, azelaic, sebacic, fumaric, maleic, itaconic, 1,3-cyclopentane dicarboxylic, 1,4-cyclohexane dicarboxylic, phthalic, terephthalic, isophthalic, 2,5-norbornane dicarboxylic, 1,4-naphthalic, diphenic, 4,4-oxydibenzoic, diglycolic, thiodipropionic, 4,4-sulfonyldibenzoic, and 2,5-naphthalene dicarboxylic acids.
In the examples which follow all temperatures are in degrees centigrade and all proportions are by weight unless otherwise stated. It is to be understood that these examples are intended to be illustrative and are not intended to indicate any restriction in the scope of the invention.
The flammability of the flame-retardant antistatic polymer additives of the invention was evaluated by the following method. A nylon 6 jersey No. 322 (Testfabrics, Incorporated) was treated with an isopropanol solution containing the flame-retardant antistatic polymer of the invention. After treatment, the fabric was conditioned overnight at ambient temperature and humidity conditions to insure that the major amount of solvent had evaporated prior to evaluation. In evaluating the treated fabric for fire retardancy, a sample strip measuring 4 inches wide by slightly longer than 16 inches was attached to a frame held at an angle of 45 degrees and the fabric was ignited using a Bunsen burner. The number of ignitions necessary to insure the total consumption of 16 inches of fabric was recorded.
The surface resistivity of the flame-retardant antistatic polymers of the invention was evaluated using a Keithly apparatus. Surface resistivity measurements generally correlate with the ability of the polymer to retain a static electricity charge. This apparatus was a Model 610C multi-range electrometer, Model 240A regulated power supply with a Model 6105 resistivity adaptor. For the purposes of the test, the humidity was regulated with an automatic relative humidity control system consisting of a Kewannee Dry-Box modified so that the relative humidity within the cabinet could be reproducibly controlled. An indicating hygrometer controller Model 15-3252 was employed in conjunction with a pre-calibrated narrow range, Hygrosensors Model H-103 to activate or deactivate an air pump connected in series with a column containing a desiccant such as calcium sulfate. This equipment was found to reliably control relative humidity between the 10 and 30 percent range which was of interest.
Samples were prepared for evaluation of surface resistivity by pouring a uniform film of molten sample on three small glass plates. These films were then conditioned for a period of between 48 and 72 hours at a relative humidity of 10 percent. The samples were evaluated in triplicate, reconditioned for another 24 hours at 20 percent relative humidity level and again measured and, subsequently, conditioned at 30 percent relative humidity for 24 hours prior to obtaining the last measurements.
The thermal stability of the flame-retardant antistatic polymers of the invention was evaluated using a Du Pont Model 990 thermal analyzer in both air and nitrogen. The gas flow was regulated so as to provide a flow of 50 milliliters per minute and the heating rate was 10° C. per minute.
EXAMPLE 1
A flame-retardant antistatic polymer of the invention was prepared by obtaining a halogen containing substantially hydroxyl-terminated polyester of tetrabromophthalic anhydride and ethylene glycol. This was then chemically reacted with a polyester of a chain extended tetrol based on a diamine by combining said tetrol based polyester with said halogen containing polyester and cross-linking the mixture using dimethyl terephthalate.
Specifically, the flame-retardant antistatic polymer of the invention was prepared by utilizing a four-neck, four-liter, round bottom reaction flask equipped with a stirrer, temperature control well, condenser and nitrogen inlet. Into this flask there was charged 79.5 grams (1.28 moles) of ethylene glycol, 0.9 gram (0.009 mole) of potassium acetate, and 500 grams (1.05 moles) of tetrabromophthalic anhydride. The mixture was refluxed at 180° C. for 15 minutes. More potassium acetate was added (0.9 gram) and reflux continued for 1 hour and 15 minutes. The condenser was then replaced by a distillation head and the mixture heated to 180° C. to 190° C. at atmospheric pressure. After 2 hours, 5 grams (0.08 mole) of ethylene glycol was added and heating continued at atmospheric pressure for 3 hours. The bromine-containing polyester obtained had an acid number of 35.2 and an OH number of 38.8.
Into a one-liter, four-neck, round bottom flask eqipped with a mechanical stirrer, temperature control well, nitrogen inlet and a vacuum distillation head and a condenser there was charged 640 grams of a chain extended tetrol based on a diamine sold under the trademark "TETRONIC® 1504" having a molecular weight of 12,500 together with 0.53 gram of 85 percent phosphoric acid. The reaction mixture was evacuated to 0.4 millimeter of mercury and stripped for 40 minutes at 160° C. After vacuum was relieved with nitrogen, 8.4 grams of dimethyl terephthalate was added to the reaction mixture which was then evacuated to 0.4 millimeter and stripped at 160° C. for 25 minutes. After this time the sample had a viscosity of 10,300 centipoises (Brookfield at 100° C.). After stripping an additional hour, there was added to the reaction mixture 1.5 grams of dimethyl terephthalate, 1.0 gram of sodium methoxide and 80.0 grams of the halogen-containing polyester prepared above. The mixture was stirred for 10 minutes and vacuum stripping was then carried out at 160° C. at a vacuum of about 1 millimeter of mercury over a period of 90 minutes. There was then added 0.5 gram of an 85 percent phosphoric acid solution. After another 35 minutes of vacuum stripping the resultant flame-retardant antistatic polymer had a viscosity of 24,000 centipoises (Brookfield at 100° C.), an OH number of 9.2, an acid number of 0.54 and a bromine content of 6.9 percent.
EXAMPLES 2-4
The procedure of Example 1 was repeated using a sufficient amount of bromine-containing polyester to produce antistatic polymers of the invention having respectively 4.5, 10 and 14.9 percent bromine.
EXAMPLE 5
In this example there is prepared a flame-retardant antistatic polymer of the invention based upon an alkoxylated tetrabromobisphenol A. By the process of the invention the tetrabromobisphenol A is converted to a chain extended diol. A mixture of this chain extended diol is then chemically combined with a chain extended tetrol based on a diamine by a cross-linking reaction with dimethyl terephthalate to obtain the completed flame-retardant antistatic additive of the invention. The specific steps in the process are as follows:
Into a four-neck, three-liter, round bottom flask equipped with mechanical stirrer, temperature control well, nitrogen inlet and vacuum distillation head and condenser, there was charged 1094 grams of a chain extended tetrol made by first ethoxylating under base catalysis N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine and then propoxylating to give a product with a hydroxyl number of 24-28 containing approximately 45 percent propylene oxide. This mixture was heated to 80° C. and was utilized at this stage in the process merely to provide a reaction medium as an alternative to the use of an organic solvent in which to conduct the reaction. Next, there was added to the flask 1037 grams of an ethoxylated tetrabromobisphenol A product having 3 moles of ethylene oxide per mole of tetrabromobisphenol A. The mixture was then heated to 120° C. and stirring continued for one hour until a homogeneous solution resulted. There was then added to this solution 7.5 grams of sodium methoxide and the mixture stirred and heated for 30 minutes. After vacuum was applied, the temperature was increased to 150° C. and the mixture stripped for 3 hours until a red-brown homogeneous solution resulted.
A one-gallon, steam-heated autoclave was charged with 1600 grams of the red-brown homogeneous solution prepared above. The mixture was purged with nitrogen and pressure was then reduced to less than or equal to 10 millimeters of mercury and the mixture stripped at 115° C. for 15 minutes. The vacuum was then relieved with nitrogen and a pressure of 2 pounds per square inch applied. Propylene oxide was then added over a period of 4 hours for a total of 1000 grams. After an additional 2 hours, the mixture had attained constant pressure and was then cooled to 80° C. and the product discharged. Stripping of the products obtained indicated that 220 grams of propylene oxide had been chemically incorporated into the product.
A one-liter, four-neck, round bottom flask equipped with a mechanical stirrer, temperature control well, nitrogen inlet and a vacuum distillation head and condenser was charged with 468 grams of the above propoxylated product together with 0.90 gram of an 85 percent phosphoric acid solution. A vacuum of one millimeter mercury was applied and the mixture stripped for 45 minutes during which time the temperature was increased from 120° C. to 160° C. The vacuum was then relieved with nitrogen and 5.1 grams of sodium methoxide added. The vacuum was reapplied and stripping continued for 30 minutes. Vacuum was relieved with nitrogen and 17 grams of dimethyl terephthalate was added. The reaction mixture was stirred for 15 minutes and vacuum reapplied. Stripping at a pressure of one millimeter of mercury was continued over a period of 2 hours. Sodium methoxide was added in the amount of 5.1 grams, followed by the addition of 17 grams of dimethyl terephthalate over three subsequent additions with stripping continued between additions. The product obtained had a final viscosity of 24,000 centipoises (Brookfield at 100° C.), an OH number of 37.2 and an alkalinity number of 0.709 and 19 percent bromine.
The product was evaluated for stability at elevated temperature by thermal gravimetric analysis. It was determined using a Mettler Thermoanalyzer that a 1 percent weight total loss occurs at a temperature of 320° C. under conditions of heating at 100-gram sample at 8° C. per minute under a nitrogen atmosphere. Most commercial antistatic additives intended for use as components of an extruded polymer mixture have a degree of heat stability indicated by a 1 percent weight loss in the above test at a temperature of about 300° C. or above.
EXAMPLE 6
A flame-retardant antistatic polymer additive of the invention was prepared by following the procedure of Example 1 except that the substantially hydroxylterminated polyester of ethylene glycol was prepared using chlorendic anhydride (1,4,5,6,7,7-hexachlorobicyclo(2.2.1.)-5-heptene-2,3-dicarboxylic anhydride) in place of the tetrabromophthalic anhydride of Example 1. Said polyester had an acid number of 27 and a hydroxyl number of 84. The resulting flame-retardant antistatic additive had a final viscosity of 27,500 centipoises, an OH number of 15.8, an acid number of 23.2 and 5 percent chlorine.
EXAMPLE 7 (Comparative Example)
A comparative or control example was prepared forming no part of this invention by reacting a chain extended tetrol based on a diamine, sold under the trademark "TETRONIC® 1504" with dimethyl terephthalate in the ratio of 100 parts TETRONIC 1504 to 1.33 parts dimethyl terephthalate in accordance with the procedure of Example 1 except for final neutralization with 85 percent H 3 PO 4 . The resulting polyester had a final viscosity of 11,000 centipoises, an OH number of 11.9 and an acid number of 0.22.
The flammability of nylon fabrics coated with the flame-retardant antistatic polymer additives of the invention are shown in the tables below. The coated nylon 6 fabric appears less flammable than the coated nylon 66 fabric. The results show generally an ascending order of resistance to burning as the proportion of bromine in the polymer additive is increased where the coating weight is substantially constant.
TABLE I______________________________________NYLON 6 FABRICFLAMMABILITY UPON TREATMENT WITH FLAMERETARDANT ANTISTATIC POLYMER ADDITIVES Number of Halogen Ignitions for in Coating Combustion of Additive Weight 16" of FabricExample No. (%) (%) (Average of 6)______________________________________2 4.5 (Br) 12.7 4.21 6.9 (Br) 13.5 6.74 14.9 (Br) 13.6 8.36 5.0 (Cl) 14.5 6.77 (Control) -- 15.3 1.0______________________________________
TABLE II______________________________________NYLON 66 FABRICFLAMMABILITY UPON TREATMENT WITH FLAMERETARDANT ANTISTATIC POLYMER ADDITIVES Number of Halogen Ignitions of in Coating Combustion of Additive Weight 16" of FabricExample No. (%) (%) (Average of 6)______________________________________5 19 (Br) 19.2 4.33 10 (Br) 14.2 1.26 5 (Cl) 18.1 1.57 -- 15.3 1.0______________________________________
The surface resistivity of the flame-retardant antistatic polymers of the invention was evaluated using a Keithly apparatus according to the procedure described above. The results of the evaluation of the various antistatic polymers prepared in Examples 1-6 are shown in Table III. It will be noted that the surface resistivity is generally comparable to that shown in the control sample (Example 7), with the results averaging about 10 at 20 percent relative humidity for the majority of the samples tested.
TABLE III______________________________________KEITHLY SURFACE RESISTIVITY (Log.sub.10)OF FLAME RETARDANT ANTISTATIC POLYMERS % Halogen Relative Humidity in (%)Example No. Polymer 10% 20% 30%______________________________________1 4.5 9.9 9.7 9.35 19 11.7 10.9 10.16 5 9.9 9.7 9.37 (Control) 0 9.9 9.8 9.65 19 11.5 11.1 10.8______________________________________
While this invention has been described with reference to certain specific embodiments, it will be recognized by those skilled in the art that many variations are possible without departing from the scope and spirit of the invention.
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Flame-retardant antistatic polymer additives are provided which inhibit the buildup of electrostatic charges upon the addition of such compositions to synthetic polymeric fibers, i.e., polyamide fibers, and at the same time do not contribute to the flammability characteristics of such polymeric fibers. The flame-retardant antistatic polymer compositions are useful in combinations with fibers such as polyamide, polyester, polyurea, polyurethane, polysulfonamide, polyolefin and polyacrylic fibers. The antistatic effect is obtained by the process of coating the fibers or dispersing in or on the fibers up to about 12 percent by weight of a polymer composition which is the reaction product of:
(a) a polyoxyalkylene compound or polyester thereof and
(b) at least one reactant selected from the group consisting of (1) a diol, (2) a polyester and (3) an aliphatic or aromatic diacid or derivative of (3), wherein at least one said reactant is halogenated.
Improved flame-retardant properties can be obtained by including with the flame-retardant, antistatic polymer composition an effective flame retardant proportion of a compound from group Vb of the periodic table. Generally about 1:4 to about 4:2 parts halogen to antimony compound is used. Such compounds are oxides of metals such as phosphorus, arsenic, antimony, or bismuth with the preferred compound being antimony trioxide.
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This application is the U.S. national phase of International Application No. PCT/IB2008/054832, filed 18 Nov. 2008, which designated the U.S. and claims the benefit of FR Application No. 07/08189, filed 22 Nov. 2007, the entire contents of each of which are hereby incorporated by reference.
The invention relates to single-domain antibody (sdAb) fragments capable of inhibiting the HIV Nef protein and to the immunological applications thereof, more particularly in immunotherapy for AIDS treatment.
BACKGROUND OF THE INVENTION
The recognition specificity of antibodies for hitting a given target has been exploited for the diagnosis and therapy of various pathological conditions, and most particularly in the case of acquired immunodeficiency syndrome (AIDS), where the target can be a protein of human immunodeficiency viruses type 1 or 2 (HIV-1 and HIV-2).
In the context of the search for candidate antibodies for neutralizing an HIV protein, the inventors have oriented their studies toward particular antibodies, devoid of a light chain, identified in camelids (camel, dromedary, llama) (Hamers-Casterman et al., 1993).
Camelid single heavy-chain antibody variable domains (VHH), which specifically recognize one type of antigen, have been selected from an immunized animal and have been produced from plasmid constructs. As shown in the examples, these antibody fragments have been found to be capable of specifically targeting regions of the HIV Nef (negative regulatory factor) protein that are involved in the development of acquired immunodeficiency syndrome (AIDS).
The aim of the invention is therefore to provide single heavy-chain antibody fragments (also called sdAbs for single-domain antibodies), having the desired target and epitope recognition properties.
The aim of the invention is also to provide a method for producing these antibody fragments. According to yet another aspect, the invention is directed toward the immunotherapeutic applications thereof.
SUMMARY OF THE INVENTION
The sdAb fragments of the invention are characterized in that they are anti-HIV Nef protein fragments corresponding to all or part of the VHH domains of camelids, in particular llamas.
According to an aspect of general interest, these fragments exhibit great stability and can be obtained in large amounts in soluble forms in bacteria, yeasts or any other system of production from prokaryotic or eukaryotic cells.
Their high stability enables them to acquire and maintain correct folding and therefore to remain soluble even under conditions which do not allow the formation of disulfide bridges, such as the cytoplasm of bacteria or of eukaryotic cells.
The invention is in particular directed toward the anti-Nef antibody fragments having an amino acid sequence as encoded by a nucleotide sequence chosen from the group comprising the sequences SEQ ID Nos. 1 to 6.
The invention is thus more especially directed toward the anti-Nef antibody fragments having an amino acid sequence chosen from the group comprising the sequences SEQ ID Nos. 7 to 12.
The invention is also directed toward CDRs of these sdAb fragments.
The nucleic acids capable of encoding said fragments also come within the field of the invention. The invention is in particular directed toward, as novel products, the nucleic acids corresponding to the sequences SEQ ID Nos. 1 to 6.
The invention is also directed toward a method for producing the anti-Nef antibody fragments defined above.
This method is characterized in that it comprises:
immunization of camelids, in particular of llamas, with the Nef protein as immunogen, purification of the B lymphocytes recovered from the blood, construction of a VHH library, and isolation of the sdAb fragments from the library and purification of said fragments.
More especially, the Nef protein used for the immunization lacks its first 56 amino acids.
The construction of the library advantageously comprises:
extraction of the total RNA from the B lymphocytes, reverse transcription of the RNAs so as to obtain the corresponding cDNAs, PCR amplification of the genes encoding the variable regions of the anti-Nef single heavy-chain antibodies, ligation of VHH DNA fragments, obtained by enzyme cleavage of the amplified DNAs with a phagemid.
Preferably, the sdAbs are isolated from the libraries by means of the phage display technique and are purified.
The various sdAbs obtained have been validated in terms of specificity and affinity, as illustrated by the examples.
In accordance with the invention, the selected sdAb genes have subsequently been inserted into expression vectors, in particular plasmids, so as to produce various anti-Nef sdAbs capable of binding to Nef in HIV-infected cells.
These expression vectors also constitute novel products, and the invention is therefore also directed toward said expression vectors.
The invention is more especially directed toward expression vectors, in particular plasmids, containing between two unique restriction enzyme sites, the promoters, the signal sequences and the nucleotide sequences capable of encoding the sdAb fragments defined above, or the CDRs regions of the sdAbs.
These vectors, in particular these plasmids, are capable of expressing the fragments of the invention in large amounts, in soluble forms, for example in bacteria.
The invention is thus directed towards the plasmids pET14bNef13, pET14bNefW12, pET14bNefW10, pHen6HisGS, pHenPhoA6His, pHen-sdAb Nef1, pHen-sdAb Nef2, pHen-sdAb Nef5, pHen-sdAb Nef12, pHen-sdAb Nef19, pHen-sdAb Nef20, pET-sdAb Nef1, pET-sdAb Nef2, pET-sdAb Nef5, pET-sdAb Nef12, pET-sdAb Nef19, pET-sdAb Nef20, pcDNA-sdAb Nef19 having the sequences SEQ ID Nos. 13 to 30, respectively.
The genes encoding the sdAbs are inserted between unique restriction enzyme sites in the various plasmids.
The plasmids according to the invention are capable of expressing the sdAbs defined above in large amounts, in soluble forms, for example in bacteria. The regions encoding the sdAbs can be easily transferred into other prokaryotic or alternatively eukaryotic expression systems or else transferred into plasmids intended to be transfected in to eukaryotic cells.
The identification, in accordance with the invention, of a new target for intervention, represented by a direct inhibition of the functions of the Nef viral protein during natural infection with HIV, constitutes an original approach for developing antiviral molecules capable of disrupting HIV replication in the target cell, but also of improving the immune response of the infected patients.
The invention is therefore directed toward benefiting from the immunological properties of the antibody fragments in immunotherapy.
In a first embodiment, the invention is more especially directed toward the antibody fragments defined above, where appropriate, vectorized, for use as medicaments.
The pharmaceutical compositions of the invention are then characterized in that they contain an effective amount of at least one sdAb fragment as defined above, in combination with a pharmaceutically acceptable carrier.
According to one embodiment of the invention, these compositions can be used as antiviral medicaments. In this application, the sdAb fragments are vectorized in order to cross the cell membrane and to be released within the infected cell.
The vector, for example, a peptide sequence, may be conjugated to the sequence of the fragments.
As a variant, the vector is combined with the sdAb fragments and corresponds, for example, to lipid compounds.
According to another embodiment, the pharmaceutical compositions of the invention are used in immunotherapy in order to inhibit Nef molecules released into the plasma environment.
The pharmaceutical compositions above are advantageously in forms suitable for oral or injectable administration.
In another embodiment, the invention is directed toward a gene therapy medicament constituted of a transfection vector comprising a nucleic acid as defined above, encoding an sdAb fragment of the invention.
Vectors that can be used for gene therapy purposes comprise adenoviruses, adeno-associated viruses (AAVs) and retroviruses.
These medicaments are used for intracellular immunization by transfection of infected cells.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the invention will be given in the examples which follow, in which reference is made to FIGS. 1 to 10 , which represent, respectively,
FIG. 1 , (A) titration curves for the sdAb Nef1-phage, sdAb Nef2-phage, sdAb Nef5-phage and sdAb Nef19-phage on the Nef protein adsorbed in the wells of a microplate and (B) curves of competition for the binding of the sdAb Nef5-phage and sdAb Nef19-phage to the Nef W10 protein adsorbed in the wells of a microplate, by the soluble Nef W10 protein,
FIG. 2 , an SDS-PAGE gel showing the fractions of the sdAb Nef19 protein purified on TALON,
FIG. 3 , (A) titration curves for sdAb Nef5 and sdAb Nef19 on the Nef W10 protein adsorbed in the wells of a microplate, (B) titration curve for sdAb Nef5 after amplification of the signal, and (C) curve of competition for the binding of sdAb Nef19 to the Nef W10 protein adsorbed in the wells of a microplate, by the soluble Nef W10 protein,
FIG. 4 , table of the affinity constants of sdAb Nef19, obtained by Biacore,
FIG. 5 , co-localization, analyzed by immuno-fluorescence, of sdAb Nef19 with the Nef protein in HeLa cells,
FIG. 6 , (A) flow cytometry analysis of the inhibition, by sdAb Nef19, of the effect of Nef on the level of expression of CD4 at the surface of HPB-ALL T cells and (B) flow cytometry analysis of the inhibition, by sdAb Nef19, of the effect of Nef on the level of expression of CD4 at the surface of HeLa cells,
FIG. 7 (A) flow cytometry analysis of the inhibition, by sdAb Nef19, of the ability of Nef to interact with the cellular machinery of the endocytosis pathway when it is expressed in the form of a CD8-Nef fusion in HeLa cells and (B) immunofluorescence analysis of the inhibition, by sdAb Nef19, of the ability of Nef to interact with the cellular machinery of the endocytosis pathway when it is expressed in the form of a CD8-Nef fusion in HeLa cells,
FIG. 8 , analysis, by means of coimmuno-precipitation experiments, of the interaction of sdAb Nef19 with the Nef protein in 293T cells,
FIG. 9 , analysis of the inhibition, by sdAb Nef19, of the infection capacity of HIV-1 during a single replication cycle measured on (A) HeLa-CD4 cells and (B) HPB-ALL T cells,
FIG. 10 , analysis of the incorporation of sdAb Nef19 into viral particles.
DETAILED DESCRIPTION OF THE INVENTION
Example 1
Construction of the various expression vectors for producing recombinant truncated Nef proteins in E. coli and for selecting sdAbs from sdAb-phage libraries
a—Cloning of Various Versions of The Nef Protein in pET14b for their Production in E. coli
a1—Obtaining of the Nef 13 Clone
Oligonucleotides Used:
5′Nef-Nco1-pET SEQ ID No. 34: CTTTAAGAAGGAGATATACCATGGGCCAYCAYCAYCAYCAYCAYGGNTCN GAAGCACAAGAGGAGGAGGAG 3′Nef-Blpl-pET SEQ ID No. 35: GGGGTTATGCTAGTTATTGCTCAGCGTTCTTGAAGTACTCCGGATG
PCR Conditions:
One μl (5 ng) of plasmid pNef-GST (gene encoding amino acids 57 to 205 of the Nef protein inserted into the plasmid pGEX-2T (GE Healthcare)), 5 μl of 10× Deep-Vent buffer, 1 μl of 100 mM MgSO 4 , 4 μl of 2.5 mM dNTP mix, 10 μM of each oligonucleotide (5′ Nef-Nco-pET and 3′ Nef-Blp1-pET), 0.5 U of Deep Vent in a final volume of 50 μl (94° C., 3 min; 94° C., 1 min; 55° C., 1 min; 72° C., 1 min, 30 cycles and then 72° C. 10 min). The PCR products are purified using a 2% agarose gel (Qiagen gel extraction kit, final volume 30 μl).
Cloning of the PCR Fragment into the Plasmid pET14b:
20 μl of the PCR fragment and 5 μl (2.5 μg) of the pET14b vector (Novagen) are cleaved with 10 U of Nco I and Blp I for 16H at 37° C. The enzymes are inactivated for 10 minutes at 65° C. Each DNA is then precipitated and taken up with 20 μl of H 2 O.
The ligation is carried out with 5 μl of fragment, 0.5 μl of vector and 3 Weiss units of T4 DNA ligase (Biolabs) in a final volume of 10 μl for 2H at ambient temperature. Competent (CaCl 2 technique) BL21(DE3) bacteria are transformed with 5 μl of the ligation product. The plasmid pET14bNef13, the nucleotide sequence of which is given in the appendix (SEQ ID No. 13), is thus obtained, and makes it possible to produce the Nef13 clone, the amino acid sequence of which is given in the appendix (SEQ ID No. 31).
a2—Obtaining of the NefW12 Clone
Oligonucleotides Used:
5′Nef.Nco1.W SEQ ID No. 36: CTTTAAGAAGGAGATATACCATGGGCCACCACCATCATCATCACGGATCC GCCTGGCTAGAAGCACAAGAGGAGGAGGAG 3′Nef-Blp1-pET SEQ ID No. 37: GGGGTTATGCTAGTTATTGCTCAGCGTTCTTGAAGTACTCCGGATG
PCR Conditions on pET14bNef13:
One μl (5 ng) of plasmid pET14bNef13, 10 μM of each oligonucleotide (5′ Nef.Nco.W and 3′ Nef-Blp1-pET), 0.5 U of Dynazyme (94° C., 3 min; 94° C., 1 min; 55° C., 1 min; 72° C., 1 min, 30 cycles, then 72° C., 10 min). The PCR products are purified using a 2% agarose gel (Qiagen gel extraction kit, final volume 50 μl).
Cloning of the PCR fragment into the plasmid pET14b: 20 μl of PCR fragment and 5 μl (2.5 μg) of the pET14b vector are cleaved with 10 U of NCo I and Blp I for 16H at 37° C. The enzymes are inactivated for 10 minutes at 65° C. Each DNA is then precipitated and the pellet is taken up with 20 μl of H 2 O.
The ligation is carried out with 5 μl of fragment, 0.5 μl of vector and 3 Weiss units of T4 DNA ligase (Biolabs) in a final volume of 10 μl for 2H at ambient temperature. Competent (CaCl 2 technique) BL21(DE3) bacteria are transformed with 5 μl of the ligation product. The plasmid pET14bNefW12, the nucleotide sequence of which is given in the appendix (SEQ ID No. 14), is thus obtained and makes it possible to produce the Nef W12 clone, the amino acid sequence of which is given in SEQ ID No. 32.
a3—Obtaining of the Nef W10 Clone
Oligonucleotides Used:
5′Nef/pET SEQ ID No. 38: TTAAGAAGGAGATATACCATGGGCTGGCTNGARGCNCARGARGAGGAGGA GGTGGGT 3′Nef/pJF-pET SEQ ID No. 39: GGGGTTATGCTAGTTAGCTCAGCAAGCTTAGGATCCGTGATGATGATGGT GGTGTGCGGCCGCGTTCTTGAAGTACTCCGGATG
PCR Conditions on pET14bNef13:
One μl (5 ng) of plasmid pET14bNef13, 5 μl of 10× Dynazyme buffer, 4 μl of 2.5 mM dNTP mix, 10 μM of each oligonucleotide (5′ Nef.Nco.W and 3′ Nef-Blp1-pET), 0.5 U of Dynazyme, in a final volume of 50 μl (94° C., 3 min; 94° C., 1 min; 55° C., 1 min; 72° C., 1 min, 30 cycles then 72° C., 10 min). The PCR products are purified using a 2% agarose gel (Qiagen gel extraction kit, final volume 50 μl).
Cloning of the PCR fragment into the plasmid pET14b: 20 μl of PCR fragment and 5 μl (2.5 μg) of the pET14b vector are cleaved with 10 U of NCo I and Blp I for 16H at 37° C. The enzymes are inactivated for 10 minutes at 65° C. Each DNA is then precipitated and taken up with 20 μl of H 2 O.
The ligation is carried out with 5 μl of fragment, 0.5 μl of the vector and 3 Weiss units of T4 DNA ligase (Biolabs) in a final volume of 10 μl for 2H at ambient temperature. Competent (CaCl 2 technique) BL21(DE3) bacteria are transformed with 5 μl of the ligation product. The plasmid pET14bNefW10, the nucleotide sequence of which is given in the appendix (SEQ ID No. 15), is thus obtained and makes it possible to produce the Nef W10 clone, the amino acid sequence of which is given in the annexe (SEQ ID No. 33).
All the genes encoding the various versions of Nef inserted into the plasmids of pET14b type were verified by sequencing on an ABI 310 with oligonucleotides internal to Nef:
5′Int.Nef SEQ ID No. 40: CACACAAGGCTACTTCCC 3′ Int.Nef SEQ ID No. 41: CAACTGGTACTAGCTTGTAG
b—Construction of Phagemids pHen6HisGS and pHen6HisPhoA for Library Construction
b1—Obtaining of the pHen6HisGS Phagemid
The 6HisGlySer motif is inserted downstream of the sequence encoding the c-myc tag of the pHen1 phagemid (Hoogenboom et al., 1991) by overlapping PCR.
Oligonucleotides Used:
Sup-6HisGS/P3 SEQ ID No. 42: 5′ CATCACCACCATCACCATGGGAGCTAGACTGTTGAAAGTTGTTTAGC AAAACC Inf-6HisGS/cmyc SEQ ID No. 43: 5′ GCTCCCATGGTGATGGTGGTGATGTGCGGCCCCATTCAGATCCTC Amont[Upstream]-Hind3 SEQ ID No. 44: 5′ AACAGCTATGACCATG Aval[Downstream]-Bsm1 SEQ ID No. 45: 5′ GCAAGCCCAATAGGAACCC
PCR1 and PCR2 Conditions:
One μl pHen1 at 50 ng/μl, 10 μl 10× Dynazyme buffer (Biolabs), 2 μl dNTP mix at 100 nM, 2 μl 5′ oligonucleotide at 10 pmol/μl, 2 μl 3′ oligonucleotide at 10 pmol/μl (pairs of primers used: PCR 1: Amont[Upstream]-Hind3 and Inf-6HisGS/cmyc; PCR 2: Sup-6HisGS/P3 and Ava1[Downstream]-Bsm1), 0.7 μl of Dynazyme Taq polymerase (Biolabs), 82 μl H 2 O.
PCR program used: 95° C., 3 min; 95° C., 45 s; 50° C., 45 s; 72° C., 45 s; 72° C., 3 min; 30 cycles. The size of the PCR1 and PCR2 fragments is verified on a 1% agarose gel and then the fragments are purified using the “Qiaquick gel extraction” kit (Qiagen). These two fragments are then used for the overlapping PCR3.
PCR 3 Conditions:
0.75 μl of each product of PCR1 and PCR2, 10 μl 10× Dynazyme buffer (Biolabs), 2 μl dNTP mix at 100 nM, 2 μl oligonucleotide Amont[Upstream]-Hind3 at 10 pmol/μl, 2 μl oligonucleotide Aval[Downstream]-Bsm1 at 10 pmol/μl, 0.7 μl of Dynazyme Taq polymerase (Biolabs), 82 μl H 2 O.
PCR program used: 95° C., 3 min; 95° C., 45 s; 50° C., 45 s; 72° C., 45 s; 72° C., 3 min; 30 cycles. The size of the PCR3 fragment is verified on a 1% agarose gel and then the fragments are purified using the “Qiaquick gel extraction” kit (Qiagen). This fragment is then used for cloning.
The analysis of the PCR3 product on a 1% agarose gel is in accordance with what is expected (424 bp). This fragment was purified using the “Qiaquick gel extraction” kit (Qiagen) and was then cloned.
Cloning:
The PCR3 product is purified and cleaved, in a volume of 50 μl, with 20 units of HindIII restriction enzyme in the presence of BSA, at 37° C., for 4 h. Twenty units of the BsmI restriction enzyme are then added, and the sample is incubated at 65° C. for 4 h. The BsmI enzyme is denatured at 80° C. for 20 min.
Ten μg of pHen1 are cleaved, in a volume of 50 μl, with 20 units of HindIII restriction enzyme in the presence of BSA, at 37° C., for 4 h. Twenty units of the BsmI restriction enzyme are then added, and the sample is incubated at 65° C. for 4 h. The BsmI enzyme is denatured at 80° C. for 20 min.
The cleavage products are analyzed on a 0.7% agarose gel in order to verify the cleavage.
The PCR3 product and the pHen1 that have been cleaved with HindIII and BsmI are purified on a 0.7% gel using the “Qiaquick gel extraction” kit (Qiagen).
The PCR fragment is then cloned into the pHen1 phagemid between the HindIII and BsmI sites (insert DNA/phagemid molar ratio 1/5; 2000 units of T4 DNA ligase (Biolabs); 2 h at 20° C.). The ligase is denatured at 65° C. for 15 min.
Competent TG1 bacteria are transformed with 10 μl of ligation product. A phagemid preparation was then carried out using an isolated column and sequencing was carried out. The expression of the p3 protein of pHen6HisGS was verified by Western blotting using an antibody directed against the p3 protein. The sequence was found to be in accordance with what was expected. The nucleotide sequence of pHen6HisGS is given in the appendix (SEQ ID No. 16).
b2—Obtaining of the pHenPhoA6His Phagemid
The new pHen6HisGS vector can be directly used for constructing the naive library. It is advantageous to improve it in order to facilitate the evaluation of the cloning efficiency. This is because the isolation of VHH (or sdAb) with good specificity and in large number requires libraries of wide diversity to be obtained. Very good cloning efficiency is therefore necessary during library construction.
The phoA gene encoding alkaline phosphatase is inserted into the pHen6HisGS phagemid upstream of the gene encoding the c-myc tag.
This gene, inserted in the correct reading frame, allows the synthesis of a “PhoA-cmyc-6HisGs-p3” fusion protein which has the phosphatase activity. A colorimetric selection thus makes it possible to distinguish the vectors closed up on themselves (blue colonies) from the vectors having inserted, in place of the PhoA gene, the genes encoding VHH or sdAb (white colonies).
Firstly, the sequencing coding PhoA was amplified, from the plasmid p55PhoA6HisGS/NAB- (Baty et al., CNRS/INSERM patent WO/2006/064136) with specific primers for cloning into the pHen6HisGS phagemid.
Oligonucleotides Used:
5′ PhoA/pHen SEQ ID No. 46: 5′ GGATTGTTATTACTCGCGGCCCAGCCGGCCATGGCAGCCGATCCTCG AGAGCTCCCG 3′ PhoA/pHen SEQ ID No. 47: 5′ GAGATGAGTTTTTGTTCTGCGGCCGCTTTCAGCCCCAGAGCGGCTTT C
PCR Conditions:
One μl p55PhoA6HisGS/NAB- at 50 ng/μl, 10 μl 10× Dynazyme buffer (Biolabs), 2 μl dNTP mix at 100 nM, 2 μl 5′ PhoA/pHen oligonucleotide at 10 pmol/μl, 2 μl 3′ PhoA/pHen oligonucleotide at 10 pmol/μl, 0.7 μl of Dynazyme Taq polymerase (Biolabs), 82 μl H 2 O.
PCR program used: 95° C., 3 min; 95° C., 1 min; 60° C., 1 min; 72° C., 1 min; 72° C., 10 min; 35 cycles.
The PCR product is analyzed on a 1% agarose gel. The PCR product purified using the “Qiaquick gel extraction” kit (Qiagen) is cleaved, in a volume of 50 μl, with 20 units of SfiI restriction enzyme in the presence of BSA, at 50° C., 16 h. Twenty units of the NotI restriction enzyme are then added, and the sample is incubated at 37° C. for 4 h.
Ten μg of pHen6HisGS are cleaved, in a volume of 50 μl, with 20 units of the SfiI restriction enzyme in the presence of BSA at 50° C. for 4 h. Twenty units of the NotI restriction enzyme are then added, and the sample is incubated at 37° C. for 4 h.
The PCR product and the pHen6HisGS that have been cleaved with SfiI and NotI are purified on a 0.7% gel using the “Qiaquick gel extraction” kit (Qiagen).
Cloning:
The PCR fragment is then cloned into the pHen6HisGS phagemid between the SfiI and NotI sites (insert DNA/phagemid molar ration 1/1; 1000 units of T4 DNA ligase (Biolabs); 2 h at 20° C.). The ligase is denatured at 65° C. for 15 min.
Competent TG1 bacteria are transformed with 10 μl of ligation product, and then plated out on LB medium/100 μg/ml ampicillin/30 μg/ml BCIP.
A preparation of the phagemid was then prepared using a blue colony. The expression of the PhoA-cmyc-6HisGS-p3 fusion protein was verified, as was the efficiency of the phagemid for infection. The nucleotide sequence of pHenPhoA6His phagemid is given in the appendix (SEQ ID No. 17).
c—Immunization of Llamas and Purification of B Lymphocytes
A male llama was immunized with region 57 to 205 of the recombinant Nef protein (Nef57-205) of HIV-1.
The animal was immunized every month, for three months, with 500 μg of Nef57-205. One hundred ml of blood were taken 15 days after each immunization. For each of the samples taken, the sera and the purified antibodies (IgG1, 2 and 3) were titered in order to detect the presence of antibodies against the Nef57-205 immunogen. The B lymphocytes were then purified on a Ficoll gradient (histopaque-1077, Sigma-Aldrich), and then washed twice with PBS.
d—Construction of Phage-sdAb Libraries: Purification of Total RNA, Reverse Transcription, PCR1, PCR2 and Cloning into the pHen6HisGS and pHenPhoA6His Phagemids
d1—Purification of Total RNA
Total RNA of the B lymphocytes is extracted according to the method using guanidium isothiocyanate (Chomczynski and Sacchi, 1987). After phenol/chloroform extraction in an acidic medium, the total RNA is precipitated with ethanol. The quality of the RNA and the quantification thereof are evaluated on a 1% agarose gel. It is then converted to cDNA by reverse transcription.
d2—Reverse Transcription and PCRs
Oligonucleotides Used:
3′CH2FORTA4
SEQ ID No. 48:
CGCCATCAAGGTACCAGTTGA
3′CH2-2
SEQ ID No. 49:
GGTACGTGCTGTTGAACTGTTCC
3′RC-IgG2
SEQ ID No. 50:
GGAGCTGGGGTCTTCGCTGTGGTGCG
3′RC-IgG3
SEQ ID No. 51:
TGGTTGTGGTTTTGGTGTCTTGGGTT
5′VH1-Sfi
SEQ ID No. 52:
CATGCCATGACTCGCGGCCCAGCCGGCCATGGCCCAGGTGCAGCTGGTGC
AGTCTGG
5′VH2-Sfi
SEQ ID No. 53:
CATGCCATGACTCGCGGCCCAGCCGGCCATGGCCCAGGTCACCTTGAAGG
AGTCTGG
5′VH3-Sfi
SEQ ID No. 54:
CATGCCATGACTCGCGGCCCAGCCGGCCATGGCCGAGGTGCAGCTGGTGG
AGTCTGG
5′VH4-Sfi
SEQ ID No. 55:
CATGCCATGACTCGCGGCCCAGCCGGCCATGGCCCAGGTGCAGCTGCAGG
AGTCGGG
3′VHH-Not
SEQ ID No. 56:
CACGATTCTGCGGCCGCTGAGGAGAC(AG)GTGACCTGGGTCC
Five μg of total RNA are hybridized with 1 pmol of 3′ CH2FORTA4 (Arbabi Ghahroudi et al., 1997) or CH2-2 oligonucleotide specific for the CH2 domain of llama single heavy-chain IgGs, and reverse-transcribed with 150 U of superscript II (BRL) for 30 min at 50° C. The oligonucleotides specific for the hinge regions of IgG2 and 3, 3′ RC-IgG2 and 3′ RC-IgG3, can also be used. The single-stranded cDNAs are purified on beads (BioMagR Carboxyl Terminator, Polyscience Inc) and eluted with 17 μl of 10 mM Tris-acetate, pH 7.8.
d3—PCR1, PCR2
PCR1 Conditions:
Four μl of cDNA are amplified by PCR with 0.5 U of Dynazyme Extend DNA polymerase (Finnzymes), 10 pmol of the same 3′ CH2FORTA4 or CH2-2 primer and 10 pmol of the four 5′ VH1-4 Sfi primers specific for the VH domain of human IgGs, in a volume of 50 μl (94° C., 3 min; 94° C., 1 min; 60° C., 1 min; 72° C., 1 min; 37 cycles, then 72° C., 10 min).
Three DNA fragments are amplified: a fragment of approximately 900 bp encoding the VH-CH1-CH2 domains of IgG1; and 2 fragments of approximately 600 bp encoding the VHH-CH2 domains of IgG2 and 3.
PCR2 Conditions:
The 600 bp fragments are purified on a 1% agarose gel (“Qiaquick gel extraction” kit, Qiagen) and then amplified by PCR with 1 U of Deep Vent (Biolabs) and 10 pmol of the four 5′ VH1-4 Sfi primers specific for the VH domain of human IgG and 10 pmol of the 3′ VHH-NotI primer (94° C., 3 min; 94° C., 45 sec; 65° C., 45 sec; 72° C., 45 sec; 15 cycles, then 94° C., 45 sec; 60° C., 45 sec; 72° C., 45 sec; 15 further cycles, then 72° C., 10 min).
The fragments of approximately 400 bp encoding the VHHs are purified on a 1% agarose gel (“Qiaquick gel extraction” kit, Qiagen), combined and precipitated with ethanol. They are then cleaved with the NcoI and NotI, or BglI and NotI, restriction enzymes (Biolabs) so as to be cloned into the pHen16hisPhoA phagemid at the NcoI and NotI or SfiI and NotI sites.
d4—Cloning into the Phagemids
Preparation of the pHen6HisGS Phagemid (or pHen6HisPhoA phagemid for the “naive” library):
Twenty μg of pHen6HisGS phagemid are cleaved, in a volume of 300 μl, with 50 U of SfiI in the presence of BSA, at 50° C. for 16 h; or with 50 U of NcoI in the presence of BSA, at 37° C. for 16 h. The linearized phagemid is purified on a 0.7% agarose gel (“Qiaquick gel extraction” kit, Qiagen). The DNA eluted is then cleaved with 50 U of NotI at 37° C. in a volume of 200 μl for 16 h. The enzyme is destroyed by heat for 15 minutes at 65° C. and the DNA is extracted with phenol/chloroform and precipitated with ethanol. The cleaved pHen6HisGS is checked on a 0.7% agarose gel, quantified and adjusted to 200 ng/μl.
Preparation of the DNA Fragments Encoding the sdAbs:
Five μg of VHH fragments are cleaved, in a volume of 300 μl, with 50 U of BglI and NotI in the presence of BSA, at 37° C. for 16 h; or with 50 U of NcoI and NotI in the presence of BSA, at 37° C. for 16 h. The enzymes are denatured at 65° C. for 15 min; the DNAs are then extracted with phenol/chloroform and precipitated with ethanol in the presence of 10 μg of glycogen (Roche). The VHH fragments cleaved with NcoI and NotI are purified on a 1% agarose gel, and then checked on a 2% agarose gel, quantified and adjusted to 100 ng/μl.
Ligation:
One hundred and fifty ng of pHen6HisGS cleaved with SfiI and NotI are ligated with 60 ng of VHH fragment cleaved with BglI and NotI, in a volume of 20 μl, with 2000 U of T4 DNA ligase (Biolabs) at 16° C. for 17 h.
The ligase is inactivated at 65° C. for 15 min, and the ligation product is cleaved with 20 U of XhoI (Biolabs) so as to eliminate the unligated residual vector, at 37° C. for 4 h. Six ligations are thus performed. The ligation products are then combined in two tubes and extracted with phenol/chloroform, precipitated in the presence of 10 μg of glycogen and taken up in 2×18 μl of ultrapure H 2 O. Two μl are used by electroporation. The colonies from various electroporations are combined. The male llama sdAb-phage library represents 4.1×10 4 clones.
e—Construction of the “Naive” sdAB-Phage Library Using Nonimmunized Llamas
The library was constructed exactly as described for the immune library, with the following modifications:
the phagemid used is pHenPhoA6His, the blood (approximately 2400 ml) was taken from about sixty nonimmunized llamas originating from 4 different farms.
The “naive” sdAb-phage library represents 3 107 clones.
f—Selection of sdAbs from the Libraries Using the Phage-Display Technique
The various sdAbs were isolated using the phage-display technique (Smith, 1985; Hoogenboom et al., 1991) irrespective of the library used.
f1—Production of the Phage Library:
Ten μl of the library stock (TG1 cells transformed with the phagemids) are inoculated into 50 ml of 2TY containing 100 μg/ml of ampicillin and 2% glucose, and incubated at 37° C. until an OD600 equal to 0.5 is obtained. Five ml of the culture are then infected with 5 ml of M13KO7 at 10 13 pfu/ml and incubated for 30 min at 37° C. with no agitation. After centrifugation, the phage pellet is taken up in 25 ml of 2TY containing 100 μg/ml of ampicillin and 25 μg/ml kanamycin. The culture is incubated for 16 h at 30° C. with agitation. The phages are then precipitated with 1/5 vol of 2.5M NaCl/20% PEG 6000 and concentrated 25-fold in PBS.
f2—sdAb Selection:
Two hundred μl of streptavidin-coated beads (Dynabeads M-280, Dynal) are equilibrated with 1 ml of 2% milk/PBS for 45 min at ambient temperature with agitation on a wheel. 10 12 phages from the production previously described are also equilibrated with 2% milk/PBS in a final volume of 500 μl for 60 min at ambient temperature with agitation on a wheel.
The beads are compacted with a magnet, suspended in 250 μl of 2% milk/PBS and incubated with 200 μl of biotinylated antigen for 30 min at ambient temperature on a wheel. 150, 75 and 25 nM, final concentration, of biotinylated antigen are used in the 1st, 2nd and 3rd round, respectively.
500 μl of phages are added to the 450 μl of beads/antigen-biotin for 3 h at ambient temperature with agitation on a wheel. The beads/antigen-biotin/phage mixture is washed 5 times with 800 μl of 4% milk/PBS, and then transferred into a new Eppendorf tube. Five other washes are carried out with 800 μl of PBS/0.1% Tween, and the mixture is then transferred into a new Eppendorf tube. Finally, 5 washes are carried out with 800 μl of PBS.
The antibody phages bound to the beads/antigen-biotin are suspended in 200 μl of PBS and incubated for 30 min at 37° C., with no agitation, with 1 ml of TG1 made competent for binding of the phages to the pili (competent cells: starting from an overnight culture of TG1 in 2YT, a 1/100 dilution is made and 50 ml of 2YT are inoculated at 37° C. with agitation until an OD600 close to 0.5 is obtained). At each selection, the phages are counted and amplified for a further round of selection.
f3—Counting the Selections:
Dilutions of the TG1 cells transfected with the phages (see above) of 10 −2 to 10 −5 are made with 2YT. One, 10 and 100 μl of each dilution are plated out onto Petri dishes (2YT/100 μg/ml ampicillin/2% glucose). The dishes are incubated for 16 h at 30° C.
f4—Plating Out the Selection for Isolation of Colonies:
The 5 ml of transfected TG1 are centrifuged for 10 min at 3000 g in order to concentrate the cells, and the pellet is taken up with 1 ml of 2YT. Two hundred and fifty μl are plated out per Petri dish (12 cm×12 cm)(2TY/100 μg/ml ampicillin/2% glucose) and incubated for 16 h at 30° C.
f5—Selection Results Assessment
f6—“Immune” Library
Two sdAbs specific for the Nef protein were isolated by this method: sdAb Nef19 (SEQ ID Nos. 1 and 7) and sdAb Nef20 (SEQ ID Nos. 2 and 8).
f7—“Naive” Library
Four sdAbs specific for the Nef protein were isolated by this method: sdAb Nef1 (SEQ ID Nos. 3 and 9), sdAb Nef2 (SEQ ID Nos. 4 and 10), sdAb Nef5 (SEQ ID Nos. 5 and 11) and sdAb Nef12 (SEQ ID Nos. 6 and 12).
The sequences were aligned according to the IMGT international nomenclature (The international ImmunoGeneTics information system)(Lefranc, 2003).
g—Production of sdAb-Phages and Counting
g1—Unitary sdAb-Phage Production:
Twenty ml of 2TY (100 μg/ml ampicillin; 2% glucose) are inoculated with one isolated colony of TG1 containing the phagemid corresponding to the sdAb-phage selected. The culture is incubated at 37° C. with agitation until an OD600 nm close to 0.5 is obtained. Five ml of this culture are infected with 5 to 10 μl of M13KO7 helper phage (10 13 pfu/ml) and incubated for 30 min at 37° C. in a water bath (with no agitation). The culture is centrifuged for 10 min at 3000 g and the supernatant is removed. The pellet is taken up with 25 ml of 2TY (100 μg/ml ampicillin; 25 μg/ml kanamycin). The culture is incubated at 30° C. for 16 h with agitation, and then the vessel is placed in ice for 10 min. The culture is then centrifuged for 20 min at 3000 g, 4° C. The supernatant is removed and precipitated by adding 1/5 volume of 2.5M NaCl/20% PEG 6000 for 1 h in ice. The solution is centrifuged for 20 min at 3000 g, 4° C. The pellet is taken up with 1 ml of PBS and transferred into a siliconized Eppendorf tube. A rapid precipitation is carried out by adding 200 μl of NaCl/PEG, followed by centrifuging at 13 000 rpm. The pellet is taken up with 1 ml of PBS and centrifuged for 1 min at 13 000 rpm. The supernatant is filtered through 0.45 μm and transferred into a siliconized Eppendorf tube and then stored at 4° C.
g2—Counting of the sdAb-Page Solution:
TG1 cells are cultured in 2YT at 37° C. Successive dilutions (10-fold) of sdAb-phage are made in siliconized Eppendorf tubes containing 500 μl of 2YT. When the TG1 cells are at an OD600 nm of 0.5, 500 μl of TG1 are added, and then the cells are left for 30 min at 37° C. without agitation. One hundred μl of each tube are plated out on 2YT (100 μg/ml ampicillin; 2% glucose) Petri dishes. The dishes are incubated for 16 h at 30° C. or 37° C. The colonies are counted in order to determine the number of sdAb-phages in the starting solution. This solution will be used to characterize the sdAb-phages by ELISA.
h—Characterization of Anti-Nef sdAb-Phages by ELISA
h1—sdAb-Phage ELISA:
Five μg/ml of biotinylated antigen (Nef W10) are bound to a streptavidin plate (BioBind Assembly Streptavidin Coated, ThermoLabsystems) presaturated with 2% milk/PBS. Various sdAb-phage dilutions are brought into contact with the antigen. The antigen/antibody binding is detected by means of an ELISA composed of a monoclonal antibody directed against the P8 protein of the phage (HRP/anti-M13 monoclonal conjugate, Pharmacia). Addition of the substrate, 10 mg ABTS (diammonium salt of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), to 20 ml of revealing buffer (18 ml PBS, 1 ml of 1M citric acid, 1 ml of 1M sodium citrate, 10 ml of 30% H 2 O 2 ) makes it possible to read the reaction at 405 nm (Tecan).
FIG. 1A shows the results obtained with the sdAb Nef1-phage, sdAb Nef2-phage and sdAb Nef5-phage obtained with the “naive” library and the sdAb Nef19-phage obtained from the “immune” library. In all the titration curves, a decrease in the measurement of the interaction between the sdAb-phages and the biotinylated Nef W10 protein, bound in streptavidin-coated wells of a microplate, is observed when the amount of sdAb-phage decreases. In order to demonstrate that this interaction is specific, competition ELISAs were carried out. For this, a constant amount of sdAb-phage (approximately 10 10 phage particles) was preincubated with various amounts of nonbiotinylated Nef W10 protein for 16 h at 4° C. The ELISAs are then carried out as described previously. FIG. 1B shows that the binding of the sdAb Nef5-phage and the sdAb Nef19-phage to the biotinylated Nef W10 decreases when the nonbiotinylated Nef W10 protein is increased in the assay. This decrease proves the specificity of the interaction between the sdAb-phages and the Nef W10 protein. Equivalent results are obtained with the other sdAb-phages selected.
i—Production and Purification of sdAbs from the pHen6HisGS or pHen6HisPhoA Phagemids
i1—sdAb Production:
An isolated colony is inoculated into 3 ml of 2YT/100 μg/ml ampicillin/2% glucose and incubated at 37° C. with agitation. Fifty ml of 2YT/100 μg/ml ampicillin/2% glucose are then inoculated with a dilution of the previous culture and incubated for 16 h at 30° C. with agitation. Four hundred ml of 2YT/100 μg/ml ampicillin are inoculated with the equivalent of 0.1 OD600 nm units, and incubated at 30° C. with agitation, until an OD600 nm of 0.5 to 0.7 is obtained. The culture is then induced with IPTG (isopropyl-β-D-thiogalactopyranoside; 0.1 mM of final concentration) and cultured at 30° C. for 16 h.
i2—Extraction of the Soluble Fraction of the Periplasm:
The cultures from which the sdAbs are produced are centrifuged at 4200 g, 4° C., for 40 min. The pellet is taken up in 4 ml of ice-cold TES (0.2M Tris-HCl, ph 8.0; 0.5 mM EDTA; 0.5M sucrose). 160 μl of lysozyme (10 mg/ml in TES, freshly prepared) are then added, followed by 24 ml of cold TES diluted to 1/2 in H 2 O. The mixture is incubated for 30 min in ice. 150 μl of DNAse (10 mg/ml) and a final concentration of 5 mM of MgCl 2 are then added for 30 min at ambient temperature. After centrifugation at 4200 g, 4° C., for 40 min, the supernatant (corresponding to the periplasmic fraction) is recovered. The solution is dialyzed for 16 h against the equilibrating buffer (50 mM sodium acetate, 0.1M NaCl, pH 7.0).
i3—sdAb Purification:
The column (BD TALON™ Metal affinity, BD Biosciences Clontech) is equilibrated with the equilibrating buffer (50 mM sodium acetate, 0.1M NaCl, pH 7.0). The periplasmic fraction is loaded onto the column. After the column has been washed with 5 volumes of equilibrating buffer, the sdAb is eluted by means of a pH or imidazole gradient (gradient between the equilibrating buffer, pH 7.0, and the 50 mM sodium acetate solution, pH 5.0, or the imidazole solution from 0 to 200 mM). Each fraction is checked on an SDS/PAGE gel (15% acrylamide) after staining with coomassie blue. The fractions of interest are combined and dialyzed against PBS. The sdAb is concentrated on a membrane (Amicon Ultra 5000MWCO, Millipore) and assayed by the Lowry colorimetric method using the Biorad Protein Assay kit.
FIG. 2 shows a purification profile (C: load; NR: fraction not retained on the column; L: loading buffer wash). sdAb Nef19 is eluted (fractions 9 to 56) with a pH gradient of 7 to 5.
i4—Characterization of the Anti-Nef sdAbs by ELISA
Five μg/ml of biotinylated antigen (Nef W10) are bound to a streptavidin plate (BioBind Assembly Streptavidin Coated, ThermoLabsystems) presaturated with 2% milk/PBS. Each sdAb (range of 0.001 μg/ml to 1 μg/ml) is bound to the antigen adsorbed in the microwells. The binding is revealed with a monoclonal antibody, 9E10, directed against the c-myc tag (Santa Cruz Biotechnology, Inc), diluted to 1/1000, and a peroxidase-coupled goat polyclonal antibody directed against mouse IgG, diluted to 1/5000 (ref 55556, ICN), in the presence of ABTS (diammonium salt of 2,2′-azinobis(3-ethylbenzthiazoline sulfonate)(Roche).
FIG. 3A gives the results obtained with sdAb Nef5 and sdAb Nef19. In all the titration curves, a decrease in the measurement of the interaction between the sdAbs and the biotinylated Nef W10 protein; bound in streptavidin-coated wells of a microplate, is observed when the amount of sdAb decreases. Since sdAb Nef5 has a lower affinity than sdAb Nef19, an amplification of the signal ( FIG. 3B ) was obtained by preincubating sdAb Nef5 with the mAb 9E10 for 1 h at 25° C. before depositing in the wells of the microplate. As a control, the mAb 9E10 was used in the absence of sdAb.
As for the sdAb-phages, competition ELISAs were carried out. For this, a constant amount of sdAb (5 μg/ml) was preincubated with various amounts of nonbiotinylated Nef W10 protein for 16 h at 4° C. The ELISAs are then carried out as described previously. FIG. 3C shows that the binding of sdAb Nef19 to the biotinylated Nef W10 decreases when the amount of nonbiotinylated Nef W10 protein in the assay is increased. This decrease proves the specificity of the interaction of sdAb Nef19 for the Nef W10 protein. Equivalent results are obtained with the other sdAbs.
j—Cloning of sdAb Nef19 into the Plasmid pET14bNefW10
10 μl of the pET14bNefW10 vector and 5 μl of the pHen-sdAb Nef19 vector are cleaved with 10 U of NcoI and NotI for 16 h at 37° C. The fragments are purified on 1% agarose (Qiagen gel extraction kit, final volume 50 μl for the pET14bNefW10 vector and 20 μl for the fragment corresponding to the sequence of sdAb Nef19).
The ligation is carried out with 10 μl of fragment and 1 μl of vector in a final volume of 15 μl in the presence of 3 Weiss units of T4 DNA ligase (Biolabs) for 2 h at ambient temperature.
Competent (CaCl 2 technique) BL21(DE3) bacteria are transformed with 7.5 μl of the ligation product. The plasmid pET-sdAb Nef19 (SEQ ID No. 28), the sequence of which is indicated in the appendix, is obtained.
h—Affinity Constants of The Anti-Nef Antibody Using Biacore
BIACORE uses the principle of surface plasmon resonance (SPR) to follow, in real time, the interactions between molecules without labeling said molecules. One of the interaction partners is covalently immobilized on a biosensor, while the other is injected in a continuous stream. The principle of detection by SPR makes it possible to follow the changes in mass at the surface of the biosensor, due to the formation and then the dissociation of molecular complexes. The response, quantified in resonance units (RU), is a direct indication of the degree of binding of the analyte by the measurement of the variation in refractive index. The recording of the signal (a sensorgram) is processed mathematically so as to obtain the association rate constant ka and the dissociation rate constant kd and the equilibrium association constant KA (KA=ka/kd) and the equilibrium dissociation constant KD (KD=kd/ka).
The interactions between Nef W10 and sdAb Nef19 produced either from the periplasm (sdAb Nef19P) or from the cytoplasm (sdAb Nef19C) of bacteria were studied on a BIACORE 3000 equipped with a CM5 biosensor on which 1089 RU of Nef W10 were covalently immobilized according to the standard amine-coupling procedure proposed by BIACORE (activation with NHS/EDC). sdAb Nef19P or sdAb Nef19C (in buffer: 10 mM HEPES; 150 mM NaCl; 3 mM EDTA; 0.005% surfactant P20) is then injected. In parallel, the injections are carried out on a control channel which has undergone the same chemical coupling, but without injection of protein. The affinity constants for sdAb Nef19P and sdAb Nef19C, of SEQ ID Nos. 1 and 7, are indicated in FIG. 4 (it should be noted that sdAb Nef19P and sdAb Nef19C have the same amino acid sequences).
k—Construction of The Plasmid Allowing Intracellular Expression of the sdAB Nef19 in Eukaryotic Cells and Study of the Cellular Distribution of sdAb Nef19
k1—Obtaining of the Plasmid pcDNA-sdAb Nef19
Oligonucleotides Used:
SEQ ID No. 57:
ANefEcoK5p
5′GAATTCCACCATGGCCGAGGTGCAGCTGGTG3′
SEQ ID No. 58:
ANefXho3p
5′CTCGAGCTAGCTCCCATGGTGATGGTG
The sequence encoding sdAb Nef19, truncated by removal of its signal peptide but tagged at its C-terminal end with the c-myc and 6His epitopes, was amplified by PCR from the pHEN-sdAb Nef19 vector using the 2 nucleotide primers ANefEcoK5p and ANefXho3p.
PCR Conditions:
One μl of pHen-sdAb Nef19 at 50 ng/μl, 10 μl of 10× Dynazyme buffer (Biolabs), 2 μl of dNTP mix at 100 nM, 2 μl of 5′ oligonucleotide at 10 pmol/μl, 2 μl of 3′ oligonucleotide at 10 pmol/μl (pairs of primers used: ANefEcoK5p and ANefXho3p), 0.7 μl of Dynazyme Taq polymerase (Biolabs), 82 μl of H 2 O.
PCR program used: 95° C., 3 min; 95° C., 45 s; 50° C., 45 s; 72° C., 45 s; 72° C., 3 min; 30 cycles. The size of the PCR fragment is verified on a 1% agarose gel, and the fragments are then purified using the “Qiaquick gel extraction” kit (Qiagen).
Cloning:
Twenty μl of the purified PCR product are cleaved, in a volume of 100 μl, with 10 U of EcRI restriction enzyme and 10 U of XhoI restriction enzyme in the presence of BSA, at 37° C., for 12 h. The enzymes are then denatured at 65° C. for 20 min.
The pcDNA3.1+ vector (Invitrogen) was used for the expression of sdAb Nef19 in mammalian cells. 2.5 μg of pcDNA3.1+ are cleaved, in a volume of 100 μl, with 10 units of EcoRI restriction enzyme and 10 units of XhoI restriction enzyme in the presence of BSA, at 37° C., for 12 h. The enzymes are then denatured at 65° C. for 20 min.
The digestion products are analyzed on a 0.7% agarose gel in order to verify the digestion.
The PCR product and the pHen-sdAb Nef19 that have been cleaved with EcoRI and HindIII are purified on a 0.7% gel using the “Qiaquick gel extraction” kit (Qiagen).
The ligation is carried out with 5 μl of PCR fragment, 0.5 μl of the vector and 3 Weiss units of T4 DNA ligase (Biolabs) in a final volume of 10 μl, for 2 h at ambient temperature.
Competent TG1 bacteria are transformed with 10 μl of ligation product. A preparation of the plasmid was then carried out using an isolated colony and sequencing was carried out. The resulting plasmid, called pcDNA-sdAb Nef19, allows the production of sdAb Nef19 in eukaryotic cells transfected with this plasmid. The sequence of pcDNA-sdAb Nef19 is given in the appendix (SEQ ID No. 30).
k2—Colocalization of sdAb Nef19 with the Nef Protein at the Level of Cytoplasmic Membrane Structures
The intracellular distribution of sdAb Nef19 was analyzed by indirect immunofluorescence on HeLa cells transiently expressing the Nef-GFP fusion protein or the GFP control protein, the expression vectors of which have been previously described (Burtey et al., 2007). The cells (4×10 5 ) were transfected by the lipofection technique with Lipofectamine 2000 (Invitrogen) according to the procedure recommended by the manufacturer.
24 h after transfection, the cells were fixed for 20 min at 4° C. with a solution of PBS/4% paraformaldehyde (PFA), and then permeabilized with a solution of PBS/0.1% Triton X100 for 10 min. The sdAb was then detected using an antibody (Ab) directed against the c-myc epitope (9E10, Roche) in PBS/0.1% BSA, and then an anti-mouse IgG second Ab coupled to Alexa594 (Jackson Laboratories). The localization of the sdAb was compared with that of Nef-GFP by fluorescence microscopy using a Leica DMB microscope, and the images were edited using the Adobe Photoshop software.
The results are illustrated in FIG. 5 . While the sdAb is distributed diffusely between the cytoplasm and the nucleus (part A, central panel) in the cells expressing the GFP control protein (left panel), it becomes redistributed towards cytoplasmic membrane structures located in the perinuclear region where it colocalizes perfectly with the Nef-GFP protein (part B).
l—Study of the Effect of sdAb Nef19 on the Functional Properties of Nef
l1—Inhibition of the Effect of Nef on the Level of CD4 Expression at the Cell Surface
In order to explore the potential effects of sdAb Nef19 on the functional properties of Nef, its ability to modulate the expression of the CD4 receptor at the surface of CD4+ T lymphocytes was firstly analyzed in cells expressing the sdAb. Human T lymphoid cells of the HPB-ALL line (10 7 ), constitutively expressing the CD4 receptor, were cotransfected by electroporation (Burtey et al., 2007) with 10, 20 or 30 μg of the vector for expression of sdAb Nef19 (pcDNA-sdAb Nef19) and 5 μg of the vector for expression of the Nef-GFP fusion or of the GFP control protein. 24 h after transfection, the level of CD4 expression at the cell surface was analyzed on the cells expressing Nef-GFP or GFP by flow cytometry using a Cytomics FC500 instrument after labeling for 1 h at 4° C. with an anti-CD4 Ab directly coupled to phycoerythrin-CY5 (RPA-4, Beckton-Dickinson), and then fixing of the cells with a 3.7% formaldehyde solution.
The results are illustrated in FIG. 6A . While a representative experiment is shown on the top panel, the bottom panel corresponds to the average of the results obtained from 3 independent experiments. In the absence of sdAb Nef19, Nef leads to a decrease of approximately 70% in the level of CD4 expression at the cell surface. The expression of increasing amounts of sdAb results in a dose-dependent reversion of this effect (black bars), since the level of CD4 present at the surface of the cells expressing Nef and transfected with 30 μg of the vector for expression of sdAb Nef19 is virtually comparable to that measured in the absence of Nef. The expression of the sdAb does not induce a nonspecific effect, since said expression, even at the highest dose, does not modify the level of CD4 present at the surface of the cells expressing the GFP control protein (white bars).
This inhibitory effect of sdAb Nef19 is also observed on nonlymphoid cells stably expressing the CD4 receptor. HeLa cells stably expressing CD4 (HeLa-CD4) were cotransfected as previously using the lipofection technique, with 1, 2 or 3 μg of the vector for expression of sdAb Nef19 and 1 μg of the vector expression of Nef-GFP or of the GFP control (Coleman et al., 2006). The level of CD4 surface expression was analyzed as previously by flow cytometry on the cells expressing Nef-GFP or GFP.
The results corresponding to the averages of 3 independent experiments are reported on FIG. 6B . They show that sdAb Nef19 is capable of inhibiting to a large extent the effect of the Nef-GFP fusion on the level of CD4 surface expression (black bars).
l2—Study of the Inhibition by sdAb Nef19 of the Ability of Nef to Interact Directly with the Cellular Machinery of the Endocytosis Pathway
The use, by several teams, of a CD8-Nef fusion protein in which the extracellular and membrane regions of CD8 are fused to the N-terminal end of Nef (CD8-Nef) has made it possible to show that the sequence of Nef contains determinants which allow it to interact directly with the machinery for vesicular transport of proteins in the endocytosis pathway. The CD8-Nef membrane chimera has, like the myristoylated native Nef protein, the property of modulating in trans the surface expression of the CD4 receptor, but also of modulating in cis its own level of expression at the cell surface, thus reflecting its ability to connect directly to the cellular machinery of the endocytosis pathway.
The inhibitory effect of sdAb Nef19 on the level of surface expression of the CD8-Nef chimera was therefore explored, by flow cytometry and by immunofluorescence, on HeLa cells.
For the cytometry analysis, the cells are cotransfected by lipofection with 1, 2 or 3 μg of the vector for expression of sdAb Nef19, 0.7 μg of the vector for expression of CD8-Nef or of the CD8-Stop control corresponding to the CD8 receptor devoid of cytoplasmic domain, and 0.3 μg of the vector for expression of GFP.
24 h after transfection, the cells are fixed for 20 min with a solution of PBS-4% PFA, and the level of expression of the CD8-Nef chimera at the surface of the cells expressing GFP was evaluated using an anti-CD8 Ab (SK1, Becton-Dickinson) coupled to phycoerythrin-Cy5.
For the immunofluorescence analysis, the cells were transfected with 1 μg of the vector for expression of CD8-Nef or CD8-Stop and 1 μg of the vector for expression of the sdAb. 24 h after transfection, the cells are fixed for 20 min with a solution of PBS-4% PFA and permeabilized with a solution of PBS-0.1% Triton X100. The sdAb was detected as previously (see FIG. 5 ), whereas the CD8-Nef fusion is detected with an anti-CD8 Ab coupled to FITC (SFCI, Coulter).
The results of these experiments are illustrated in FIG. 7 . Part A corresponds to the results of the analysis by cytometry; the top panel represents a representative experiment while the bottom panel corresponds to the averages of 3 independent experiments. In the absence of sdAb Nef19, the level of expression of the CD8-Nef chimera is approximately five times lower than that of the control CD8-Stop protein (white bars). The expression of increasing amounts of the sdAb results in a gradual accumulation of the CD8-Nef protein at the cell surface (black bars). The expression of the sdAb has no effect on the level of expression of the CD8-Stop control (white bars).
The data from the immunofluorescence experiments reported on the top panels of FIG. 7B confirm these results, since a clear increase in labeling of the CD8-Nef protein at the plasma membrane is observed in the cells coexpressing sdAb Nef19 (indicated by arrows), whereas this labeling is almost exclusively concentrated in a perinuclear membrane compartment in the absence of the sdAb (cell indicated by an arrow head). As in FIG. 5 , sdAb Nef19 is distributed diffusely between the cytoplasm and the nucleus in the control cells expressing the CD8-Stop protein (bottom panels), whereas it relocalizes to the intracellular membrane structures and at the plasma membrane that are also labeled with the anti-CD8 Ab in the cells expressing the CD8-Nef fusion (top panels).
The results of FIG. 7 confirm the recognition of Nef by sdAb Nef19 in the cell context; they also confirm the inhibitory effects of the sdAb on the interactions of Nef with the cellular machinery of the endocytosis pathway.
l3—Interaction of sdAb Nef19 with the Nef Protein in the Cell Context
The direct recognition of Nef by sdAb Nef19 was explored at the cell level by means of coimmuno-precipitation experiments. 293T cells (3×10 6 ) were cotransfected, by means of the calcium phosphate precipitation technique, with 5 μg of the vector for expression of the sdAb in combination with 5 μg of a vector for expression of the CD8-wild-type Nef fusion (CD8-Nef WT), or point mutants (CD8-NefLL164-165AA and CD8-NefE62-65A) or deletion mutants of Nef (CD8-Nef 1-61 and CD8-Nef 58-189). These constructs have been previously described (Janvier et al., 2003a,b; Madrid et al., 2005). The same type of experiment was also carried out on cells coexpressing the sdAb and the CD8 protein devoid of cytoplasmic domain (CD8-Stop) used as a control. 24 h after transfection, the cells were lyzed in a buffer containing 100 mM of (NH 4 ) 2 SO 4 , 20 mM of Tris (pH 7.5), 10% of glycerol, 1% of IGEPAL and a cocktail of protease inhibitors (Roche). The cell lyzate (600 μg of total proteins) was incubated for 1 h at 4° C. with 3 μg of the anti-CD8 Ab (32M4, Santa Cruz) and 30 μl of beads coated with protein A-sepharose. The immunoprecipitates were then analyzed by immunoblotting using an anti-CD8 Ab (H160, Santa Cruz) and an anti-c-myc Ab (9E10).
The results are illustrated in FIG. 8 . As expected (left-hand panels), the band corresponding to sdAb Nef19 is specifically detected in the material immunoprecipitated from the cells expressing the CD8-Nef fusion protein, whereas it is not detected in the material immunoprecipitated from the cells expressing the control CD8-Stop protein. The analysis of the material immunoprecipitated from the cells expressing the mutated fusion proteins indicates that the sdAb is still capable of associating with the point mutants CD8-NefLL164-165AA and CD8-NefE62-65A, whereas the deletion mutants, CD8-Nef 1-61 and CD8-Nef 58-189, are not recognized by the sdAb. Since the immunogen used to generate sdAb Nef19 corresponded to a recombinant protein lacking the first 57 amino acids, the results of FIG. 8 suggest that the zone recognized by the sdAb is located at the C-terminal end of Nef, on a region between residues 190 and 206 of the protein.
l4—Inhibition, by sdAb Nef19, of the Positive Effects of Nef on the Infectious Capacity of HIV
The inhibitory activity of sdAb Nef19 on the contribution of Nef to the infectious properties of the viral particles was analyzed in an experimental system for evaluating the infectious capacity of HIV-1 during a single replication cycle (Madrid et al., 2005). Recombinant viral particles carrying the GFP reporter gene were produced by cotransfection of 293T cells as previously described (Basmaciogullari et al., 2006) with 8 μg of the vector for expression of the proteins derived from the gag and pol genes of HIV-1 (NL43 isolate) (Owens et al., 2003), 8 μg of the vector for expression of the GFP transgene, 2 μg of the vector for expression of the envelope of HIV-1 (89.6 isolate) or of VSV (VSV-G), 1 μg of the vector for expression of the Nef protein tagged at its C-terminal end with the HA epitope (Dorfman et al., 2002), and 8 μg of the vector for expression of the sdAb. The viral particles pseudotyped with the HIV-1 envelope or the VSV envelope were recovered in the culture supernatant 48 h after transfection and stored at −80° C. The virus stocks were titered by measuring reverse transcriptase (RT) activity, and then used to infect HeLa-CD4 cells or T cells of the HPB-ALL line. 3×10 4 HeLa-CD4 cells were infected in 24-well plates with 500 it of a dilution of 5×10 5 and 5×10 4 arbitrary units of RT/ml, of the virus stocks pseudotyped, respectively, with the HIV-1 or VSV envelope. In the case of the HPB-ALL line, 10 5 cells were infected with 1 ml of a dilution to 17×10 4 and 17×10 3 arbitrary units of RT/ml, of the virus stocks pseudotyped, respectively, with the HIV-1 or VSV envelope. 60 h after infection, the cells were recovered and fixed in a solution of PBS-3.7% formaldehyde, and then the percentage of cells infected, and therefore expressing GFP, is evaluated by flow cytometry.
The results corresponding to the averages of 3 independent experiments are reported in FIG. 9 . The top panel (A) corresponds to the infectious capacity of the viral particles, measured on HeLa-CD4 cells, and the bottom panel (B) corresponds to the infectious capacity measured on HPB-ALL T cells. The results are reported as a function of the infectious capacity of the viral particles pseudotyped with the HIV-1 envelope (blue bars) or the VSV envelope (maroon bars) and produced in the absence of Nef. As expected, Nef expression in the producer cells results in a clear increase in the infectious capacity of the viral particles expressing the HIV-1 envelope (14 times and 3 times, respectively, in the HeLa-CD4 and HPB-ALL cells), whereas the viruses expressing the VSV envelope are not influenced by the expression of Nef. The expression of sdAb Nef19 causes a significant and specific inhibition, of the order of 75%, of the effect of Nef on the infectious capacity of the viral particles, independently of the cell type used. Conversely, the expression of the sdAb does not influence the infectious capacity of the viral particles expressing the VSV G protein, whether the particles are produced in the absence or in the presence of Nef.
l5—Incorporation of sdAb Nef19 into the Viral Particles
Since several studies had shown that the Nef protein of HIV-1 was incorporated into the viral particles budding at the surface of the infected cells, the influence of the expression of sdAb Nef19 in the producer cells, on the incorporation of Nef into the viral particles, was therefore explored. The viral particles were produced as previously (see FIG. 9 ) in 293T cells cotransfected with 1 or 4 μg of the vector for expression of sdAb Nef19. The culture supernatants were subjected to ultracentrifugation at 27 000 rpm for 1 h 30 at 4° C. on a PBS/sucrose cushion. The viral particles thus purified were then taken up in Laemli buffer and analyzed by immunoblotting using anti-HA (3F10, Roche), anti-c-myc (9E10, Roche) and anti-p24 (obtained from the “NIH AIDS Research and Reference Reagent Program”) antibodies; the lysates of the producer cells were also analyzed by immunoblotting.
The results are illustrated in FIG. 10A . The left-hand panels correspond to the analysis of the cell lysates, whereas the right-hand panels correspond to the analysis of the purified viruses. In the absence of sdAb Nef19, the Nef-HA protein is correctly incorporated into the viral particles, as indicated by the detection of the 2 bands revealed with the anti-HA Ab (top panel), corresponding to the whole protein of 27 kDa and to the cleavage product of approximately 25 kDa (Chen et al., 1998; Welker et al., 1998). The incorporation of Nef does not appear to be disrupted by the expression of the sdAb, but the latter is also incorporated only when the viral particles have been produced from cells expressing Nef. These results show that the sdAb is specifically recruited into the infectious viral particles, probably by direct interaction with the Nef protein established in the producer cell. This recruitment of the sdAb could be responsible for its inhibitory effect on the infectious capacities of the viral particles produced.
In order to confirm that the incorporation of sdAb Nef19 into the viral particles is indeed the result of association with the Nef protein in the producer cells, the ability of the sdAb to interact with the Nef-HA protein was explored as previously by coimmunoprecipitation from 293T cells cotransfected with the vectors for, respectively, the expression of the sdAb and of Nef-HA. 600 μg of proteins derived from the soluble fraction of the cell lysates were incubated for 1 h at 4° C. with 3 μg of the anti-HA Ab (3F10) and 30 μl of beads coated with protein A-sepharose. The immunoprecipitated material was then analyzed by immunoblotting using an Ab specifically directed against the Nef protein (Ab a56 obtained from the “NIH AIDS Research and Reference Reagent Program”) and the anti-c-myc Ab (9E10).
As shown by the results reported in part B of FIG. 10 , the sdAb is detected only in the immunoprecipitate of the cells expressing Nef-HA, but is not detected in the material precipitated from the cells transfected with the Nef-Stop control vector (left-hand panels) enabling the expression of a polypeptide corresponding to the first 46 residues of the Nef protein, even though the sdAb is clearly expressed in these cells (right-hand panels).
LITERATURE REFERENCES
1. (Hamers-Casterman et al., 1993)
2. (Hoogenboom et al., 1991)
3. (Chomczynski and Sacchi, 1987)
4. (Arbabi Ghahroudi et al., 1997)
5. (Smith, 1985; Hoogenboom et al., 1991)
6. (Lefranc, 2003)
7. (Janvier et al., 2003a,b; Madrid et al., 2005)
8. (Chen et al., 1998; Welker et al., 1998)
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The invention relates to antibody fragments with simple heavy chain or sdAbs, characterized in that they consist of anti HIV Nef-protein fragments corresponding to all or a portion of the HHV domains of camelids, particularly llamas.
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BACKGROUND OF THE INVENTION
The present invention generally relates to an apparatus for coupling attachments to tools and the like, and more particularly to a ferrule for coupling an accessory attachment to a rotary hand tool
There has been continued innovation and improvement in the design of power tools, particularly rotary hand tool units of the type that are used in woodworking, metal working and the like. Examples of such products are those made under the Dremel brand by the S-B Power Tool Corporation of Chicago, Ill., which also produces many accessory attachments for such rotary hand tool units. The rotary hand tool units are generally cylindrical in shape and contain a motor with a rotary output shaft that is adapted to drive the various rotary tool bits, such as small saw blades, sander discs, grout removal tool bits and various other cutting tool bits. There are also may accessory attachments that can be used in association with the rotary hand tool units, with the accessory attachments being connected to the stationary nose end portion of the rotary hand tool unit. Among such accessory attachments is a flexible shaft attachment that conveniently allows the user to operate the various rotary tool bits around corners or in other remote areas of operation. Also useful are grout removing tool guides that conveniently position the grout removing bit relative to the tool guide so that a user can conveniently and effectively remove grout from between individual floor and wall ceramic tiles, for example. As a further example, a depth guide is a desirable accessory attachment that can be used with many types of cutting tools to limit the depth of penetration of the tool into a work piece or work surface.
While such accessory attachments have been available for many years, the manner in which the accessory attachments are coupled to the tool has been the subject of continuing efforts to provide a simple and effective mechanism for coupling or mounting the accessory attachments to the hand tool itself. In this regard, the necessity of tightening holding screws or utilizing multiple turns of a threaded coupling mechanism for coupling the accessory attachment to the rotary hand tool, while effective, are not considered to be particularly simple and convenient in many past designs.
SUMMARY OF THE INVENTION
The present invention is related to a particularly simple, elegant and convenient coupling apparatus for attaching an accessory attachment to a rotary hand tool unit of the type that has a housing with a nose portion through which a rotary output shaft extends. The present invention enables a coupling apparatus to be placed on the nose portion in a predetermined position and secured into locking position by a pair of hinged latch members. An accessory attachment can subsequently be attached to the other end of the coupling apparatus, which then serves to couple the accessory attachment to the rotary hand tool unit.
More particularly, the coupling apparatus includes a ferrule that is provided with inwardly protruding ribs or protrusions on opposite sides of the inside of the ferrule, where the ribs engage a pair of outwardly extended elongated arcuate teeth located on the nose portion of the rotary hand tool unit. In this type of hand tool unit, which is adapted to receive another type of attachment mechanism that can be engaged and releases with only a quarter turn of rotation on a pair of teeth, each of the teeth extends approximately 90° to 100° of the circumference of the cylindrical nose portion and is curved in the axial direction so that the center of the tooth is moved in the axial direction rearwardly or away from the end of the nose end portion. The teeth form a groove portion that extends generally circumferentially around at least a part of the nose portion so that the groove portion is located on opposite sides of the nose portion, coextensive with the elongated arcuate teeth on the nose portion. The preferred embodiment of the present invention has two latch members which are also configured and arranged on the circumference of the ferrule to oppose one another, and each latch member includes an engagement protrusion for engaging the groove portion of the nose portion, and also include a locking protrusion to engage a locking flange located on the external circumference of the ferrule.
Thus, during operation, when the coupling apparatus is slipped onto the nose portion of the hand tool unit, the inwardly protruding ribs align with and engage the elongated arcuate teeth to ensure proper alignment of the accessory attachment with the nose portion. As the latch members are locked into the closed position, the engagement protrusion engages the groove portion of the nose portion. The latch members are finally locked into place by snapping the locking protrusion into the locking flange of the ferrule. The ferrule is also configured so that the latch members, when in the locked position, can be pulled upward into the open position with force enough to overcome the frictional engagement of the locking protrusion and the locking flange, subsequently making the attachment easily releasable by simply pulling the attachment from the nose portion with relatively modest force.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of the coupling apparatus of the preferred embodiment having one of the pair of parallel vertical flanges removed, illustrated with a rotary tool unit and a flexible shaft attachment coupled thereto.
FIG. 2 is a top view of the coupling apparatus illustrated in FIG. 1 .
FIG. 3 is an exploded sectional view of the coupling apparatus illustrated in FIG. 1, taken along the 3 — 3 line of FIG. 2 .
FIG. 4 is a sectional view of the coupling apparatus illustrated in FIG. 1 taken along the 3 — 3 line of FIG. 2 .
FIG. 5 is an elevational view of the coupling apparatus illustrated in FIG. 1 .
FIG. 6 is a top perspective view of the coupling apparatus illustrated in FIG. 1 .
FIG. 7 is a side perspective view of the coupling apparatus illustrated in FIG. 1 .
FIG. 8 is a perspective view of the latch member of the coupling apparatus illustrated in FIG. 1 .
FIG. 9 is a perspective view of the stop plug apparatus used in connection with the coupling apparatus of the instant invention.
FIG. 10 is an elevational view of the stop plug apparatus of FIG. 9 .
FIG. 11 is a perspective view of the drive cap used in connection with the coupling apparatus of the instant invention.
FIG. 12 is a sectional view of the drive cap of FIG. 11 taken along the 12 — 12 line.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the coupling apparatus of the present invention is shown in the FIGS. 1 through 5, where a rotary hand tool is indicated generally at 10 and is shown in conjunction with a flexible shaft attachment indicated generally at 12 . The rotary hand tool unit 10 has a nose end portion indicated generally at 14 and a rotary output shaft 16 which is illustrated in FIG. 4 and intended to be attachable to a working tool bit such as a small circular saw blade, a cutting bit, or the like. The ferrule of the coupling apparatus is designated generally as 18 .
The hand tool unit 10 has a housing with a motor and a drive shaft, which are not shown in the drawings. As best shown in FIG. 5, the nose portion 14 is formed with the housing and includes both an enlarged diameter portion 20 and a cylindrical shaped portion 22 . The cylindrical shaped portion 22 is configured forwardly of the enlarged diameter portion 20 , and the cylindrical shaped portion contains a pair of outwardly extending elongated teeth 24 , each of which is curved in the axial direction so that the middle portion is more rearwardly positioned from the end of the nose portion 14 than either of the ends of the teeth. Each of the teeth 24 are diametrically opposite one another on the circumference of the cylindrical shaped portion 22 . Each of the teeth 20 extends around the periphery of the cylindrical shaped portion 22 approximately 90° although it may extend to 120° or more if desired.
The adjacent ends of the teeth 24 are separated by a distance sufficient to allow internally protruding ribs 26 on the coupling apparatus to pass beyond the ends of the teeth when the coupling apparatus is being coupled to the rotary hand tool unit 10 . As best illustrated in FIGS. 1 and 5, each of the elongated teeth 24 terminate at their ends in an alignment portion 28 , which is flared planar surface that slopes to a reduced height measured from the surface of the cylindrical shaped portion 22 when compared to the height of the teeth portion measured from the surface of the cylindrical shaped portion.
The interface between the enlarged diameter portion and the cylindrical portion form an annular shoulder 30 , and the distance between the shoulder and any correspondent axially oriented portion of the teeth 24 is substantially constant as best shown in FIGS. 1 and 5. The area defined by this distance forms a pair of convex groove portions 32 that are coextensive with the pair of outwardly extending elongated teeth 24 . Like the elongated teeth 24 , the groove portions 32 are diametrically opposed to one another on the cylindrical shaped portion 22 , and are curved in the axial direction so that the middle portion is more rearward positioned form the end of the nose portion 14 than either of the ends of the teeth.
Ordinarily, working tools are mounted to the rotary hand tool unit 10 by a collet and a collet nut (not shown in the drawings), which are coupled to the output shaft 16 of the rotary tool unit. The rotary tool unit 10 applies rotational torque to various working tools and the rotary output shaft 16 includes an open end portion 34 having a threaded outer circumference 36 . From its open end portion 34 toward the rotary tool unit, the rotary output shaft 16 has a predetermined interior depth and an inner circumference that gradually narrows, and is configured to matingly receive a collet, which has a circumference that is slightly larger than the narrowest portion of the inner circumference of the rotary output shaft. In this way, the collet is prevented from sliding into the predetermined interior depth of the rotary output shaft by the narrowing inner circumference of the rotary output shaft. The collet is held in place by a threaded collet nut, which threadedly engages the threaded outer circumference of the rotary output shaft.
The protruding end of the collet ordinarily includes an aperture surrounded by a plurality of spring-biased fingers, which operate to retain corresponding working tools inserted therein. Since the working tools, such as small saw blades and cutting bits, have base ends having a circumference that is much smaller than the open end of the open end portion of the output shaft, the spring-biased fingers of the collet prevent slippage or sliding of the base end the working tool into the output shaft. Thus, by using a collet and collet nut in combination with any number of rotary hand tool bits having shanks, various working tool bits may be inserted into and used with the rotary hand tool. However, when a rotary hand tool unit 10 is coupled to an accessory attachment, such as a flexible shaft attachment 12 , via the coupling device 18 of the instant invention, the collet and collet nut are removed so that the output shaft 16 can be mechanically coupled to the flexible shaft attachment, as will be described.
Turning now to FIGS. 1 through 5, which illustrate the coupling apparatus 18 coupled to a flexible shaft attachment 12 , the coupling apparatus comprises a mounting portion or ferrule having a generally hollow cylindrical body with an internal surface and an external surface. An open mounting end portion 38 is a circumferential opening in the ferrule and has a predetermined diameter configured to receive the nose portion 14 of the rotary tool unit 10 . Opposite the open mounting end portion 38 is a smaller open end portion 40 , to which the attachment 12 is mounted, where the smaller open end portion has a smaller diameter than the diameter of the open mounting end portion. Separating the two open end portions is a conical transition portion 42 , which is a sloped, funnel-shaped portion of the ferrule 18 that gradually narrows the diameter of the ferrule, and terminates in the generally cylindrical smaller open end portion 40 .
As the nose portion 14 of the rotary tool unit 10 is inserted into the open mounting end portion 38 of the ferrule 18 , at least one and preferably two sets of internally protruding ribs 26 extend in an axial direction from the open mounting end portion to the conical transition portion 42 . In the preferred embodiment of the instant invention, the internally protruding ribs 26 include two pair of elongated, parallel protruding ribs, with one pair of ribs being diametrically opposed to the other pair on the internal surface of the ferrule. However, the number and placement of the ribs may vary, depending on the configuration and placement of the corresponding flared planar surface of the teeth 24 .
The ribs 26 and the ferrule 18 are of unitary construction, with a top surface 44 of the ribs being a planar surface. This planar surface 44 corresponds to the alignment portion 28 of the teeth 24 on the nose portion 14 of the rotary tool unit 10 , and both surfaces are configured and arranged in predetermined positions so that alignment of these surfaces ensures proper alignment of the rotary tool unit within the ferrule 18 . Because the height of the teeth 24 measured from the surface of the cylindrical shaped portion 22 is lowest at the alignment portions 28 , the ribs 26 are configured to extend from the internal surface at a distance corresponding diameter of the nose portion 14 at the alignment portion so as to frictionally engage the alignment portion of the teeth when inserted. Because the protruding ribs 26 of the preferred embodiment are diametrically opposed, the rotary tool unit 10 only be inserted in one of two positions, which only differ by a 180° degree of separation and are indiscernible for purposes of attachment. The engagement of the alignment portion 28 with the ribs 26 therefore prevents improper alignment of the rotary tool unit 10 within the ferrule 18 , and restricts rotational movement of the rotary tool unit once it is inserted into the ferrule.
Turning now to FIGS. 3 through 5, the ferrule of the instant invention includes at least one and preferably two locking latch members 46 for releasably securing the ferrule 18 to the rotary tool unit 10 . In the preferred embodiment, the external surface of the ferrule includes two diametrically opposed latch mounting portions, designated generally at 48 (best shown in FIG. 6 ), separated from each other by approximately 180°, to which the latch member 46 is mounted. Each latch mounting portion 48 includes a pair of parallel vertical flanges 50 , which each flange having inside and outside walls 52 , 54 , and the inside walls of each flange face one another. Each pair of vertical flanges 50 are unitary with the external surface of the ferrule, and extend radially from the circumference of the ferrule, generally parallel to one another. There is an opening or a discontinuity in the ferrule body 18 , where the opening is defined between the inside walls 52 of the pair of flanges and extends downward for at least a portion of the open mounting end portion 38 . In the preferred embodiment of the instant invention, the opening in the ferrule 18 has a vertical length that is approximately one-half to two-thirds of the vertical length of the open mounting end portion 38 . The opening prevents the ferrule 18 from blocking interaction between the latch members 46 and the rotary tool unit 10 , once the rotary tool unit is aligned and inserted into the ferrule. It is therefore conceivable that the vertical length of the opening could be significantly shorter, or consist of an adequately sized aperture, to facilitate interaction between the latch members 46 and the rotary tool unit 10 .
An upper portion of each flange 50 contains an aperture 58 for receiving a cross bar that extends between the two flanges. It is upon this cross bar (not shown) that the latch members 46 are hingedly mounted. Therefore, when mounted, the latch members 46 may swing between an upward or open position and a closed or downward position. When the latch members 46 are in the open position, the ferrule and the tool are held in alignment by frictional engagement of the alignment portion 28 and the protruding ribs 26 . However, when the latch members 46 are in the closed position, the ferrule 18 and rotary tool unit 10 will be in locking engagement by at least one and preferably two of the following locking mechanisms.
Turning now to FIG. 8, the latch members 46 themselves contain and upper portion 60 and a lower portion 62 , where the upper portion depends vertically from the cross bar via apertures 64 in the upper portion of the latch members. The upper portion 60 is a generally flat surface that, when the latch members are in the closed position, rests flush in the plane defined by distal vertical edges of the vertical flanges. In contrast, the lower portion 62 , while unitary with the upper portion 60 , is bent slightly toward the ferrule 18 so that a distal end of the lower portion is slightly closer to the ferrule than the distal end of the upper portion. Thus, the bottom portion angles slightly inwardly toward the ferrule 18 and away from the plane defined by the distal vertical edges of the vertical flanges. The distance between the upper portion 60 of the latch member and the ferrule 18 is relatively constant, while the distance between the lower portion 62 and the ferrule will have a slight and gradual decrease at its distal end. However, the distance between the diametrically opposed latch members 46 , whether taken along the upper or lower portion, is greater than the diameter of the open mounting end portion.
The top portion of the latch members 46 include a first locking protrusion 66 , which in the preferred embodiment, is a wedge-shaped protrusion that extends generally perpendicularly from the latch member. This wedge-shaped protrusion 66 also includes a concave surface 68 at its distal end, which is configured to frictionally engages the convex groove portion 32 of the rotary tool unit 10 as the latch member 46 is brought into its closed position. The first locking protrusion 66 is also mechanically confined in frictional engagement at its underside by the elongated teeth 24 of the rotary tool unit 10 and at its upper side by the annular shoulder 30 between the enlarged diameter portion 20 and the cylindrical portion 22 of the rotary tool unit. This is the first of the two locking mechanisms.
For purposes of engaging the second locking mechanism, the latch members 48 further include a second locking protrusion 70 disposed on the lower portion of the latch member that also extends generally perpendicularly therefrom. The second locking protrusion 70 is planar on its underside, but preferably includes a raised end 72 on its top side. The latch mounting portion 48 also includes a generally horizontal shelf-like locking flange 74 having a top surface and a bottom surface, where the top surface is planar and the bottom surface includes an engagement recess 76 , which in the preferred embodiment, is an elongated longitudinal recess. Thus, as the latch member 46 is brought into its fully closed position, the second locking protrusion 70 slides underneath the locking flange 74 , frictionally engaging the bottom surface of the locking flange until the raised end 72 encounters the engagement recess 76 on the bottom surface of the locking flange and locks into place. Once the raised end 72 engages the engagement recess 76 , the raised edge is mechanically secured within the engagement recess, and both locking mechanisms of the latch member are effected, making the rotary hand tool unit 10 securely and releasably mounted to the ferrule 18 of the accessory attachment 12 .
The latch mounting portions 48 of the ferrule 18 are configured to allow the user to easily disengage the locking mechanisms using relatively modest force. Around the circumference of the transition portion 42 , two diametrically opposed vertical cut-out portions 78 (best shown in FIG. 6) are disposed below the shelf-like locking flange 74 . These vertical cut-out portions 78 are generally flat surfaces extending downward into the funnel-shaped transition portion of the ferrule, so that there is a recess in the conical shape of the transition portion 42 at each of the cut-out portions. The diameter between the recesses is less than any other given diameter of the open mounting end portion. Thus, because the distance between the diametrically opposed latch members 46 , whether taken along the upper 60 or lower portion 62 , is greater than the diameter of the open mounting end portion 38 , there is a space between the lower portion of the latch member and the generally flat surface of the cut-out portion 78 . In the preferred embodiment, the space is large enough to accommodate the user's finger, so that a user can reach into the space and pull the latch out of locking engagement. However, it is contemplated that the space could be reduced or eliminated if alternative means for opening the latch members were provided. For example, providing a grasping protrusion on an outside surface of the latch member would allow the user to pull upward on the latch member via the grasping protrusion, eliminating the need for a space.
Depending on the configuration of the specific accessory attachment 12 , the preferred embodiment of the ferrule 18 contemplates that the accessory attachment may be coupled to the ferrule 18 in a multitude of ways. By way of example only, to couple the flexible shaft attachment 12 to the ferrule 18 , a lower portion of the cylindrical smaller open end portion 40 slidably engages the generally cylindrical mounting portion, designated generally at 80 , of the flexible shaft attachment. As illustrated in FIG. 1, the mounting portion 80 of the flexible shaft attachment 12 , which includes a coiled spring 82 , couples a hollow flexible rubber sheath 84 to the ferrule 18 . The coiled spring 82 has an inner circumference that is slightly smaller than the outer circumference of the smaller open end portion 40 of the ferrule 18 . Therefore, when the coiled spring 82 is mounted around the outer circumference of the smaller open end portion 40 , the resulting force fit maintains frictional engagement of the coiled spring with the smaller open end portion of the ferrule. The flexible sheath 84 is telescopingly inserted into the coiled spring, thus aligning a top region 88 of the flexible core 86 (see FIGS. 3, 4 ) opening of the smaller open end portion 40 , which enters the ferrule 18 .
Turning now to FIGS. 3, 4 , 11 and 12 , when coupling a flexible shaft attachment 12 such as that illustrated in the drawings, a drive cap 90 having a n aperture therethrough 92 may be placed within the ferrule to receive the top region 88 of the flexible core 86 . The aperture 92 and the top region 88 of the core 86 have square cross sections and are configured to matingly engage one another so that when the drive cap is rotated, the flexible core 86 rotates as well.
However, disengagement of the flexible core 88 and the handpiece 94 frequently occurs when the handpiece is raised in a vertical direction above the horizontal plane in which the rotary tool unit 10 is operating. The rotary output shaft 16 has a predetermined depth and a circumference that is larger than the diameter of the flexible core 86 . As a consequence, the flexible core 86 that is engaged with, and protruding through the aperture 92 frequently extends into the depth of the output shaft. If not prevented from doing so, the flexible core 86 can disengage from the handpiece 94 entirely and slide further into the output shaft 16 , thereby interrupting and frustrating the work of the user.
Turning now to FIGS. 3, 9 and 10 , when the coupling attachment 18 of the instant invention is coupled to the flexible shaft attachment 12 , a stop plug apparatus 96 may optionally be used to prevent unwanted or unplanned disengagement of the flexible core 86 from the handpiece 100 . The stop plug apparatus 96 is a plastic device, preferably nylon filled glass, that has an open end portion 98 , a closed end portion 100 , and a generally cylindrical body. The open end portion 98 of the stop plug apparatus 96 nests within the drive cap 90 . Thus the open end portion 98 is aligned with the aperture 92 of the drive cap, and the open end portion accordingly receives the top region 88 of the flexible core, and the closed end portion 100 restricts axial movement in the direction of the output shaft 16 .
While a particular embodiment of the present coupling apparatus has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
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A ferrule for coupling an attachment to a rotary hand tool unit of the type that has a housing with a nose portion through which a rotary output shaft extends. The nose portion has at least one groove extending generally circumferentially around at least a part of the nose portion, so that a groove portion is located on opposite sides of the nose portion. The ferrule includes a generally hollow cylindrical body with interior and exterior surfaces with an open mounting end portion and a smaller opposite end portion to which the attachment is mounted. The open mounting end portion fits on the nose portion of the housing when the ferrule is coupled to the rotary hand tool. The ferrule further includes at least one internally protruding rib on the interior surface for aligning the ferrule in at least one predetermined angular position, and at least two latches mounted on the ferrule, with each latch having an open and a closed position wherein the ferrule is locked into the nose portion when the latch is in the closed position.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of pending application Ser. No. 498,084, filed Aug. 16, 1974, now U.S. Pat. Ser. No. 3,996,118, filed Aug. 16, 1974 which in turn is a division of application Ser. No. 252,285, filed May 11, 1972 now U.S. Pat. No. 3,849,278, filed May 11, 1972.
BACKGROUND OF THE INVENTION
This invention relates to electrolytic and electrochemical systems, apparatus and methods in which electrolytic reactions are carried out in an aqueous electrolyte and wherein there is a tendency to produce a gas, at least at the cathode. Specifically, the present invention relates to an improved electrolytic system in which gas which tends to form at one of the electrodes is reacted and removed preferably in the form of an electrolytically non-interfering oxidation-reduction reaction product. Important in the practice of this invention is a Contacogen which is the situs of the oxidation-reduction reaction between the gas tending to form at either electrode and a second gas introduced and brought into contact with the Contacogen to effect a reduction-oxidation reaction of the gas formed at the electrode, or tending to form at the electrode. The Contacogen is preferably in the form of particulate wetproofed material maintained in a static condition, as opposed to percolating or in turbulent movement, and simultaneously contacted by an aqueous media, and the reactants. In this way, the gas, if formed, is effectively eliminated.
DESCRIPTION OF THE PRIOR ART
Electrolytic processes are known in which an aqueous electrolyte is contacted by an anode and a cathode and wherein hydrogen is produced at the cathode (the electrode at which reduction takes place) while chlorine or oxygen or other gas may be formed at the anode (the electrode at which oxidation takes place). In these prior art systems, the production of one or the other of the gases at the cathode or anode presents practical problems. For example, U.S. Pat. No. 3,203,882 of Aug. 11, 1965, describes a bipolar chlorate cell used in the manufacture of alkali metal chlorate from alkali metal chloride solutions and wherein the cover of the cell acts as a collector for gases generated during electrolysis. The formation of hydrogen, oxygen and chlorine is said to present a problem of explosion. Reference is also made to U.S. Pat. No. 2,797,192 of June 25, 1957 and U.S. Pat. No. 3,463,722 of Aug. 26, 1969, in which the gases produced and the ratio thereof is described.
Another example of an electrolytic process of the type to which this invention applies is the production of chlorine and alkali in what is usually referred to as a "chlor-alkali" cell. The electrolyte is sodium chloride brine, with chlorine gas produced at the anode and hydrogen gas and sodium hydroxide produced at the cathode, the anode and cathode are usually separated by a membrane or diaphragm. Canadian Pat. No. 700,933 of Dec. 29, 1964, describes such a system wherein the cathode is in the form of a porous carbon member through which air or oxygen is introduced, the purpose, according to said patent, being to effect reaction between the cathodic gas product and oxygen and thereby to convert the usual cathode to a fuel cell type cathode. Also disclosed by this Canadian patent is the use of a slurry of particulate solids in the catholyte, the slurry being freely movable in the catholyte to contact the cathode proper. When particulate solids are used in the catholyte, they may be graphite or carbon impregnated with a metal catalyst, or metal particles, the particulate material being small enough to form an aqueous slurry which when aerated allows for free and rapid contact of such particles with the cathode. In one form, the catholyte particles may be partially coated with a hydrophobic material such as tetrafluoroethylene, silicones, etc. The conductive particles are said to act as absorbents or collectors for oxygen admitted and hydrogen evolved in the cathodic portion of the cell, and are said to accept electrons upon contact with the cathode which dissipates as they move through the electrolyte with the formation of hydroxyl ions or other hydrogen-oxygen ions and ultimately water. The data presented in this Canadian patent indicates that the presence of particulate material as a slurry in the catholyte does not significantly improve the performance of the cell as compared with operation absent the slurry. Here reference is made to a comparison of 105 Ma at 1.68 v absent the slurry vs. 110 Ma at 1.8 v with the slurry present.
It is known in the art that air or oxygen may be used to depolarize a cathode. U.S. Pat. No. 3,124,520 of Mar. 10, 1964, describes a porous graphite cathode in a caustic-chlorine diaphragm cell in which air or oxygen is introduced into the porous cathode. This method of depolarization is criticized not only because of the absence of an oxygen-to-hydroxyl ion catalyst in the electrode, but because of the nature of the catholyte which is NaOH--NaCl. Thus, it is suggested that a cation exchange membrane be used to separate anolyte and catholyte in order to form NaOH in the catholyte, and that the cathode contain a catalyst. Also disclosed is a hydrogen anode, i.e., a porous anode into which hydrogen gas is introduced in order to react with the oxygen which may be released at the anode.
U.S. Pat. No. 3,219,562 of Nov. 23, 1965, also describes the "fuel cell reaction", that is, the introduction of oxygen at the cathode which is wetproofed and which has a potential applied thereto in order to effect reduction of the oxygen by acceptance of electrons and the formation of water by reaction with hydrogen ions in the catholyte. The cathode is a porous plate impregnated with platinum and wetproofed with polytetrafluoroethylene. In one form, the cell is operated as a fuel cell with a load connected between the anode and cathode and wherein the two electrodes are separated by an ion exchange membrane, olefinic gas being introduced into the anolyte. In another form the cell is electrolytic with hydrogen released at the cathode.
U.S. Pat. No. 3,147,203 of Sept. 1, 1964, which relates to the production of carbonyl compounds from olefin feed stock, describes a fuel cell system in which oxygen is introduced into the cathode and olefin fuel gas at the anode, with power being generated.
U.S. Pat. No. 3,216,632 describes a bipolar cell for use in electrolysis in which the bipolar electrode is vertically above the anode, with the cathode portion of the bipolar electrode facing the anode and the anode portion thereof facing the cathode electrode. Hydrogen produced at the lowermost cathode diffuses through the cathode portion of the bipolar electrode and combines with oxygen at the anode portion to form water. The hydrogen released at the cathode electrode is withdrawn.
U.S. Pat. No. 2,390,591 of Dec. 11, 1945, relating to an electrolytic system for the production of oxygen gas from caustic alkali or acid solutions describes introducing air into a porous carbon cathode for the purpose of depolarizing the same. U.S. Pat. No. 3,143,698 of May 26, 1964, relates to a primary cell in which a tribromide is used to depolarize the cathode. Both oxidizing depolarizes (chlorine and oxygen introduced at the cathode) and reducing depolarizers (acetylene, etc., introduced at the anode) are disclosed.
Depolarization of an electrode by a gas is sometimes used to measure the concentration of the gas, see U.S. Pat. No. 3,247,452 of Apr. 19, 1966, wherein the change in voltage or current effected by depolarization is measured. Reference is also made to U.S. Pat. No. 3,258,415 of June 18, 1966, which uses a porous cathode and in which the depolarizing gas, and the gas being measured, is oxygen.
The use of electrolytic systems for the regeneration of ferricyanide-bromide bleach baths in photographic processing is known, see British Pat. No. 801,106, published Sept. 10, 1958.
Other patents of interest are: U.S. Pat. Nos. 524,229 of Aug. 7, 1894; 524,291 of the same date, and 530,867 of Dec. 11, 1894 all dealing with primary batteries. Also of interest is U.S. Pat. No. 2,010,608 of Aug. 6, 1935 dealing with a gas permeable carbon electrode for use in an air depolarized cell in which the electrode is impregnated with a solution of oil, paraffin, or the like.
It is known from texts (Electrochemistry, Potter, MacMillan Co., New York 1956) that cathodic hydrogen evolution involves overall
2H.sup.+ + 2e→ H.sub.2.
Several steps are said to be involved including:
(a) Migration, diffusion or travel by convection of the hydrated hydrogen ion from the bulk liquid to the cathode;
(b) A discharge, dehydration reaction in which the hydrated hydrogen ion picks up an electron from the cathode and an H atom is adsorbed on the electrode with formation of water;
(c) Combination of adsorbed H atoms with release of H 2 gas; and
(d) Reaction between the hydrated hydrogen ion, adsorbed hydrogen and an electron to form hydrogen gas.
The overpotential arising from (b), (c) and (d) is usually referred to as the activation overpotential while that from (a) is the concentration overpotential. In depolarization, adsorbed hydrogen atoms react with oxygen to form water. There is a distinction between the hydrogen evolution reaction and the hydrogen discharge reaction as follows: ##STR1## Thus, the classic depolarization reaction of the cathode involves reaction (2). Where hydrogen gas has been formed, it is usually removed as a gas. In the "fuel cell cathode", depolarization is effected by the use of air or oxygen on a porous cathode as per equation (2) supra where the hydrogen is in ionic form and adsorbed on the cathode surface.
SUMMARY OF THE INVENTION
The present invention relates to electrolytic systems and offers advantages over the systems of the prior art. Specifically the present invention utilizes a Contacogen, preferably in the form of particulate material wetproofed to prevent flooding thereof, which is maintained in a static condition and simultaneously contacted by the reactants and an aqueous media and which forms the situs of an oxidation-reduction reaction between the reactants. The Contacogen, when used in conjunction with an electrolytic system and as hereinafter defined, operates to remove gas formed at one of the electrodes, e.g., the cathode. It is not necessary for the Contacogen to be in contact with the electrode to function in the manner contemplated by the present invention, although it may be. The electrode, e.g., anode or cathode need not be porous as is required in prior art fuel cell electrodes, especially cathodes which are depolarized by the use of air or oxygen which is forced through the pores of the cathode. It is understood, however, that the Contacogen may be used in conjunction with a porous or foraminous electrode, in which event the externally supplied reactive gas need not be forced through the electrode pores as is required, for example in "fuel cell cathodes".
The type of reaction conditions with which the present invention is concerned are especially suited for Contacogen used because the reaction involves the controlled contact in a liquid phase of two gas reactants in which the contact between reactants is primarily at an interface of the Contacogen and the gases and liquid, the latter restricted contact being an essential aspect of the system of this invention. This controlled contact is in contradistinction to intermixing of the reactants as bubbles of gas in a liquid, as by a diffuser, and the reaction is carried out at that locus of contact between the liquid and gases, and the Contacogen. For the purpose of simplification, and to identify the process of this invention and the essential elements thereof, the term Contacogen is used to mean the solid material which forms the locus of the interfacial contact for the gases and liquid and which should be simultaneously contacted by each of them to produce the desired reaction.
Since the reaction zone involves two gases and a liquid, and the Contacogen, the Contacogen must be in contact with the gases and wetted by the liquid but not flooded by either. Wetted, as used here, means that the contact angle between the Contacogen and the liquid is low, e.g., less than about 90° and approaching zero. If the contact angle is high, e.g., greater than about 90° and approaching 180°, then the liquid will tend to draw away from the surface of the Contacogen, and the surface of the Contacogen is in effect in substantial contact only with the gas, that is, flooded by the gas. On the other hand, with the surface of the Contacogen readily wetted by the liquid, that is, with a contact angle approaching zero between the Contacogen surface and the liquid, the liquid will tend to cover the surface of the Contacogen, and the surface of the Contacogen is in effect in substantial contact only with the liquid, that is, "flooded" by the liquid. As a practical matter the primary source of flooding is the liquid medium present. One method of preventing flooding, usually by the liquid is by treatment of the Contacogen which is designated as "wetproofing". This adds to the Contacogen a minor proportion of an inert substance not wetted by the liquid, that is, the contact angle between this inert additive and the liquid is greater than about 90°.
The Contacogen in accordance with the invention, is a solid which is essentially inert with respect to the gases, the liquid, and the products in the sense that it is not attacked in the sense that it is physically consumed or degraded. A material having a high surface-area-to-weight ratio is preferred because it furnishes greater interfacial contact. In addition, the Contacogen is structured to promote simultaneous contact with both the gases and liquid and may be in various physical forms to accomplish this purpose. In the case of a Contacogen in particulate form, the particles are structured to provide a large surface area, for example, the particles are individually nonporous solids of large surface area, or they may be structured to form larger particles which are porous.
In the case of porous materials used as a Contacogen, it will be understood that neither the liquid nor the gaseous reactants should be forced through the pores of the Contacogen in the sense that a porous member is used as a diffuser to form small bubbles of one reactant which are in intermixing contact with the other reactant.
Various solid material may be used as a Contacogen and carbon, activated carbon, platinized materials are preferred. Of the above materials, carbon and activated carbon appear to provide optimum performance because of the relatively large surface-area-to-weight ratio obtainable, as well as the degree to which carbon may be finely divided. Moreover, this is a readily available material which may be obtained in a wide variety of particle sizes and surface areas. Carbons from different sources often result in different reaction rates. These variations are easily determined by simple procedures. Typical of the carbons usable in accordance with the present invention are carbon black, furnace black, channel black or carbons prepared by known procedures from various sources, for example, wood, corn cobs, beans, nut shells, bagasse, lignin, coals, tars, petroleum residues, bones, peat and other carbonaceous material.
The particle size may vary from 9 millimicrons to relatively large size, e.g., 1 inch or more, and usually the carbon is supplied as a mixture of various particle sizes. The surface area of the carbonaceous material may vary from 3 square meters per gram to in excess of 950 square meters per gram, as characterized by gaseous absorption using the BET method.
Carbon may be wetproofed as follows:
Polytetrafluoroethylene (PTFE) in emulsion form is intermixed with particulate carbon in an amount of between 0.1% to 100% based on carbon solids. The mixture is heated to remove the vehicle and dispersing agent for the PTFE. For further description of Contacogen and wetproofing, reference is made to Ser. No. 87,503, filed Nov. 6, 1970.
The Contacogen of the present invention does not act as an absorber of the released gas or of the externally supplied gas, nor does the effectiveness of the Contacogen depend upon transfer of electrons from the cathode to Contacogen brought into contact with the cathode or other electrode.
In the case of evolved hydrogen, it is difficult to convert the formed gas into water because of the presence of an aqueous medium which slows down the reaction of
O.sub.2 +2H.sub.2 →2H.sub.2 O
by the present invention, gaseous oxygen and hydrogen are reacted in the presence of a Contacogen and an aqueous medium to form water, the rate of reaction being significantly faster in an aqueous medium and a Contacogen than in an aqueous medium without a Contacogen. Whether classic depolarization of the cathode is accomplished in not entirely clear, especially since the depolarizing gas is not introduced into the cathode itself as is the case in the prior art. In the case of alkaline solution, the discharge step is said not to involve a hydrogen ion because the standing concentration of such ions in alkaline solutions is small. In alkaline solutions, it is believed that the discharge takes place from the water molecule, while the secondary discharge involves the water molecule in alkaline solution.
By the use of a Contacogen in accordance with this invention, wherein the Contacogen is maintained in a static condition in the bulk catholyte adjacent to the cathode, a reduction in power is sometimes observed. Whether this is attributable to offsetting of the water discharge reaction, or offsetting the primary or secondary discharge reaction in alkaline media is not really known with certainty.
Thus, the present invention is primarily useful in electrolysis systems in which an aqueous electrolyte is used, for example:
(a) Chlorate production from aqueous sodium chloride;
(b) Chlor-alkali cells for production of chlorine and sodium hydroxide;
(c) Conversion of sodium or potassium ferrocyanide in aqueous solution to the corresponding ferricyanide;
(d) Conversion of aqueous sodium sulfide to sodium polysulfide and alkali;
(e) Conversion of aqueous systems to produce high purity oxygen; and
(f) Conversion of sodium thiosulfate to sodium sulfate.
The above are merely representative to the electrolysis systems with which the present invention may be used. Each of these conversions is electrolytic in nature and characterized by formation of a gas at one electrode, usually hydrogen at the cathode, and sometimes oxygen or chlorine or both at the anode. In the usual case, however, the gases at the anode are the desired products whereas the gas at the cathode is hydrogen and presents problems due to explosion and the like.
The present invention is directed to overcoming the problem of gas production, especially at the cathode, by reacting the formed gas to eliminate its presence. This is accomplished by use of a Contacogen which is maintained in a static nonturbulent, non-percolating condition and simultaneously in contact with an aqueous medium, usually the electrolyte, and also in contact with a reducing or oxidizing gas externally applied for reaction at the Contacogen with the reactive species at or in the vicinity of the electrode. The Contacogen, in accordance with this invention is a particulate material in which each granule is wetproofed to prevent flooding by the aqueous medium so that substantially each granule is simultaneously contacted by the reactants and the aqueous medium but not flooded by any one of them.
Depending on the mode of operation, the Contacogen may be in close proximity to the electrode or removed therefrom and in communication with the gas produced at the electrode. In this mode, the Contacogen operates to accelerate the reaction between two gases in an aqueous medium conditions that normally inhibit gas-gas reactions.
Accordingly, it is a primary object of the present invention to provide a simple efficient system for reacting gases which tend to be produced at an electrode during an electrolytic process in which an aqueous electrolyte is used, and wherein the reaction by which such product is removed is an oxidation-reduction reaction involving a Contacogen to produce a reaction product which is electrolytically non-interferring with the electrolytic system.
Another object of the present invention is the provision of an improved system useable in electrolytic processes including an aqueous electrolyte by which the gas produced at the cathode is reacted with an oxidizing gas introduced into a Contacogen which is simultaneously contacted by an aqueous liquid, which may be the same or different from the electrolyte, and also contacted by the oxidizing and reducing gas for reaction therebetween in the presence of the Contacogen which is maintained in a static condition and wetproofed with respect to the aqueous medium to prevent flooding thereby.
Another object of the present invention is the provision of an improved electrolytic system wherein there is a tendency for hydrogen gas to be produced at the cathode, and wherein a Contacogen is positioned to receive the gas formed at the cathode and wherein an oxidizing gas is introduced into the Contacogen to react with the hydrogen gas, in the presence of an aqueous medium, to convert the hydrogen gas to an oxidized product as water or hydroxyl ions.
Another object of the present invention is the provision of an electrolytic system of the type described wherein a Contacogen is placed in the vicinity of a gas producing electrode and contacted but not flooded by an aqueous electrolyte and wherein a second gas is introduced into the Contacogen for the purpose of entering into an oxidation-reduction reaction with the species produced at the electrode.
Another object is the provision of an improved electrolytic system for the oxidation of an alkali metal ferrocyanide to an alkali metal ferricyanide.
Other objects and advantages of the present invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an overall electrolytic system in accordance with the present invention;
FIG. 2 is a view, partly in section and partly in elevation with portions thereof broken away, of an electrolytic cell in accordance with the present invention;
FIG. 3 is a view, partly in section and partly in elevation, of another form of electrolytic cell embodying the present invention;
FIG. 4 is a view, partly in section and partly in elevation, of an electrolytic cell of the present invention, in which the Contacogen is positioned out of contact with the electrolyte but in gas receiving relation with the gases produced at the electrodes; and
FIG. 5 is a view, partly in section and partly in elevation, of an electrolytic cell in accordance with this invention in which the Contacogen is positioned closely adjacent to the cathode but not in contact therewith.
DESCRIPTION OF THE INVENTION
The present invention will be described using the oxidation of an alkali metal ferrocyanide to an alkali metal ferricyanide. In photographic processing a ferricyanide silver bleach is used in most color reversal processing and in some color negative processing. This is a rehalogenating process in which the ferricyanide oxidizes the metallic silver image to silver ion which, in the presence of a bromide salt such as sodium bromide produces a water insoluble silver bromide salt. The basic reactions are:
K.sup.+ +Ag° + K.sub.3 Fe(CN).sub.6 ⃡Ag.sup.+ + K.sub.4 Fe(CN).sub.6
ag.sup.+ + NaBr⃡AgBr+ Na.sup.+
The bleach bath is followed by a sodium thiosulfate fixing bath which forms a water soluble silver complex. As indicated, the reactions are reversible and the buildup of ferrocyanide does not have appreciable adverse affect on bleaching time, the latter being a function of the decrease in ferricyanide concentration. Ferricyanide is one of the more expensive inorganic chemicals used in reversal color photographic processing, and its regeneration from ferrocyanide has economic value. Some of the known regenerating schemes include oxidation by bromine, oxidation by persulfate, oxidation by ozone and air oxidation. While these systems in the main are operative and have been used before there are drawbacks, e.g., bromine vapors, excessive persulfate creates acid pH with the formation of Prussian blue and free cyanide, potential health and explosion hazards of ozone, and the slowness of air oxidation.
Referring to FIG. 1, a portion of a continuous photographic processing system is shown, i.e., a bleach tank 10 through which photographic film is treated on a continuous or batch basis with a bleach solution. Typical such processes are the EA-4, ME-4, E 2, E 3, E 4 and EA-5 processes of Eastman Kodak or the AR-1 Ansco process. The bleach solution itself is a mixture of 43 to 54 g/l of sodium bromide, about 130 g/l of potassium ferricyanide, containing borax as a buffer, a nitrate for corrosion inhibition, fungicides and polyethylene glycol of molecular weight between 1540 to 4000. The bleach compositions are themselves well known. Bleach from the tank 10 is pumped via pump 12 through a filter 14 to a heat exchanger 15 and then to an electrolytic unit 20. The output of the electrolytic unit 20 is then returned to the bleach tank 10.
In the electrolytic unit 20, potassium ferrocyanide is oxidized to the ferricyanide state at the anode and there is reduction at the cathode which tends to produce hydrogen. Referring to FIG. 2, a typical electrolytic cell 20 of the present invention is shown for converting ferrocyanide to ferricyanide. The cell includes an anode compartment 21 containing the anolyte 22 in contact with an anode 23 of carbon, the anolyte being used bleach solution from the heat exchanger introduced into the anode compartment by inlet 24, oxidized anolyte leaving through outlet 26 and to flow back to the bleach tank.
Cooperating with the anode chamber is a cathode chamber 30 separated from the cathode chamber by a cation exchange membrane 34. The cathode chamber 30 includes a cathode 35 in the form of a non-porous carbon tube, in the center of which is positioned a diffuser 36 for introduction of an oxidizing gas such as air or oxygen. The cathode chamber contains a catholyte, e.g., spent bleach solution which during the course of electrolysis increases in concentration of ferrocyanide in that ferricyanide is reduced at the cathode. Also contained in the cathode chamber is a Contacogen 40 in the form of granular particulate material wetproofed, as described, and maintained in a static condition. As shown the Contacogen 40 substantially fills the cathode compartment and is supported in the electrolyte by base 41 of the cathode compartment through which the cathode extends. A power supply 42 is attached across the anode and cathode as shown.
In typical runs, the apparatus shown in FIG. 2 operated as follows: Bleach solution was pumped into the anode compartment at the rate of 25 cc/min. and the potential between the electrodes was maintained at 5 volts, the current being allowed to fluctuate.
The data based on three hours running time is as follows:
__________________________________________________________________________ Run 1 2 3 4 5__________________________________________________________________________Flow rate - air 25cc/min. 25cc/min. 25cc/min. 25cc 25ccTemperature 30° C. 30° C. 40° C. 50° C. 50° C.pH 8 6 7 8 6Rate of ferricyanide increase 4.3 × 10.sup.-.sup.5 3.3 × 10.sup.-.sup.5 6.5 × 10.sup.-.sup.5 4.2 × 10.sup.-.sup.5 8.5 × 10.sup.-.sup.5 moles/min. m/min. m/min. m/min. m/min.Concentration of ferrocyanidestart .061m .058 .060m .060m .059mFinish .052m .046m .048m .051m .043mConcentration of ferricyanidestart .340m .362m .350m .362m .372mFinish .366m .366m .372m .372m .388m__________________________________________________________________________ For the configuration shown in FIG. 2, the preferred operating conditions are 50° C. and pH 6.0.
In a typical bleach operation, bleach recirculation rate is 10 liter/min. of a tank having a 16 liter capacity. The increase in ferrocyanide due to processing of film is 1.1 grams/liter or 11 grams per 10 liters. If the nominal ferrocyanide concentration in the tank 10 is 0.45 grams/liter, conversion of ferrocyanide to ferricyanide at a rate of 2.85× 10 - 2 moles/min. or 1.2 grams/1-min. would maintain this nominal ferrocyanide concentration, i.e., the ferrocyanide concentration would not build up. In the runs described, the surface area of the anode was 0.05 ft 2 at an average current of 1.05 amps or a current density of 21 amp/ft 2 at a calculated electrical efficiency of 96%.
In order to understand better the performance of the system of the present invention, the design parameter is established such that up to 90% of the bleach solution can be recycled. For example, ferrocyanide is produced at the rate of 0.0016 moles per square foot of film processed, using the MF-4 process. Motion picture film running at 60 feet/min. involves 6.88 ft 2 of film/min. and requires the oxidation of 0.011 mole of ferrocyanide per min. To achieve this rate of oxidation, 0.0275 moles of oxygen or air at the rate of 3,060 cc/min is required. A unit in accordance with the present invention having a capacity of 15 liters and a flow rate of 500 cc/min. will be capable of oxidizing twice the required amount of ferrocyanide per minute.
It has also been observed with the apparatus of FIG. 2, that the pH at the cathode increases substantially, i.e., 14 while the pH at the anode decreases to an acidic condition, a condition which favors oxidation of ferro-to-ferricyanide. Moreover, the volume of water at the cathode does not appreciably increase. These observations tend to support the proposition that the use of an oxidizing gas results in formation of hydroxyl ions which unite with sodium and/or potassium ions coming into the catholyte through the membrane thereby forming sodium and potassium hydroxide. The source of the sodium is from the consumption of bromide by the film. In this particular case, the species formed by oxidation is believed to be hydroxyl ions, an electrolytically non-interfering material which is the oxidation-reduction reaction product. Regardless of the explanation, the fact remains that no gaseous hydrogen is evolved at the cathode, an imperforate electrode.
During operation of the unit, the ferricyanide level in the cathode was maintained above 10% and the ferrocyanide below 90% since performance of this unit seemed more efficient under these conditions. It was also observed in the absence of an oxidizing gas in the cathode and absent the Contacogen, that hydrogen was produced at the cathode.
The apparatus previously described may, in accordance with the present invention, take other forms. Referring to FIG. 3 an electrolytic photographic bleach generating unit 50 is shown including an annular electrically insulating support housing 51 receiving an annular anode 53 of 5 mil. thick tantalum. The active surface of the anode is the interior surface 54. The lower end of the housing is closed by a plug 55 while the lower end of the anode is supported on a manifold plate 56 spaced from the plug 55 by spacer 57 to provide a plenum chamber 58. Used bleach is introduced through an opening 59 in the plug 55, into the plenum 58 and through holes 61 formed in the manifold plate 56 so that bleach flows into contact with the anode surface 54.
Arranged concentrically within and spaced from the anode 54 is a cation exchange membrane 65 which is positioned between two concentrically disposed plastic sleeves 66 and 67. The sleeves are perforated as illustrated to permit contact of the electrolyte with the membrane. The ends of the sleeves 66 and 67 are sealed to their respective supports, manifold plate 56 and an upper end cap 68. Positioned within and spaced from the membrane 65 is an annular cathode 70 of tantalum, supported and centered at the lower end by a boss 71 on the manifold plate 56 and at its upper end by a boss 72 on the end cap. Both surfaces of the cathode 70 are active surfaces. Also positioned on the end cap is a siphon atomizing nozzle 75 having an air inlet 76 and a liquid intake 77 in the form of a hollow tube which extends into the chamber between the cathode and the inside surface of the membrane.
Disposed within the cathode chamber, i.e., on the inside of the tubular cathode and in the space between the cathode and the membrane is Contacogen 80. A typical Contacogen is particulate carbon wetproofed with polytetrafluoroethylene in an amount of 8% by weight and doped with 5% silver.
The volume of the membrane encircled cathode compartment is 2,550 cm 3 while the anode compartment is 850 cm 3 . The area of the electrodes in solution contact, however, is equal. The use of a 3:1 volume ratio assures full compensation for cathodic reduction of ferricyanide since efficiency of the unit may depend on ferricyanide level if the cathode compartment contains a mixture of ferri and ferrocyanide.
In operation, used bleach is introduced at inlet 59 and is distributed into the anode chamber by the ring of openings 61 in the manifold plate 56. The oxidized bleach then flows into a weir 81 for return to the bleach tank from an outlet or drain 82. The interior of the cathode contains a catholyte which may be used bleach which is drawn to the atomizer by arm 77, atomized with air and sprayed into the center of the cathode, the latter provided with holes 83 at the bottom to permit flow of catholyte into the membrane-cathode chamber. Air of reduced oxygen content exits through vent holes 84 in the end cap, which holes can also be used to introduce catholyte into the unit. A potential is applied between the electrodes by a power source 85.
The cell 50 was operated at a flow rate of 10 liter/min. with a head pressure in the cathode compartment of 20-30 psig due to the atomizing nozzle. In the course of operation, it was observed that tantalum is quite suitable as a cathode, but that an oxide formed on a tantalum anode. The use of a carbon graphite non-porous anode of 41/2 ID, 5" OD and 103/4" long was satisfactory.
In typical operations of the apparatus of FIG. 3, anolyte, i.e., used bleach was recirculated at a rate of 1 liter/min., pH 6, at 50° C. with 6 volts at 25 amps into the anode compartment. The catholyte was used bleach recirculated in the cathode chamber under 15 psig fluid pressure and atomized under 20 psig of air pressure. The rate of ferrocyanide oxidation in the anolyte was 4-6 g/l/m at an input level of 20 g/l ferrocyanide, 125 g/l ferricyanide and 20 g/l sodium bromide.
The cell of FIG. 3 was operated with bleach flowing through the cell at a prescribed rate, under 50° C. constant temperature, while the cathode was operated under conditions described above. Flow rates of 0.5, 1.0, 2.0, and 3.0 liter/minute, were evaluated over a period of time equal to the holding tank volume (16 liters, as is representative of a color Versamat) divided by the flow rate. Four sample sets were pulled at equal intervals of this recycle time period. A sample set consisted of 50 mls taken of influent to the cell and 50 mls of effluent taken X minutes later. The data collected over these four flow rates are presented below.
TABLE I*______________________________________Cell + 2 + 3 Na + TimeSolution Ferro g/l Ferri g/l Br g/l pH in Min.______________________________________Start-up 18.5 122. 21.0 6.15 0Out 10.5 5.7 9In 16.8 5.9 8Out 9.7 5.5 17In 15.2 123.5 20.8 5.7 16Out 8.4 5.25 25In 14.8 5.50 24Out 7.6 5.1 33In 12.2 125.5 20.8 5.35 32Catholyte 108.9 62.6 21.0 8.45 34______________________________________ *.45 liter/min. Bleach Recycle - 6 volts, 22 amps
TABLE II*______________________________________Cell + 2 + 3 Na + TimeSolution Ferro g/l Ferri g/l Br g/l pH in Min.______________________________________Start-up 10.9 127. 14.9 5.00 0AnolyteOut 6.8 4.1 4 1/2In 10.5 4.95 4Out 15.5 3.9 8 1/2In 9.3 128. 13.9 4.8 8Out 15.5 3.95 12 1/2In 8.4 4.7 12Out 5.0 3.7 16 1/2In 8.0 129. 14.3 4.6 16Catholyte 112.1 57.5 14.9 8.9 65Anolyte 8.0 4.8 68______________________________________ *.98 liters/min. Bleach Recycle - 6 volts, 20 amps
TABLE III*______________________________________Cell + 2 + 3 Na + TimeSolution Ferro g/l Ferri g/l Br g/l pH in Min.______________________________________Start-upAnolyte 13.3 119. 19.0 6.0 0Catholyte 109.7 53.8 20.8 8.50 0Out 12.6 5.45 2 1/4In 15.2 5.72 2Out 11.8 5.45 4 1/4In 13.5 113. 17.9 5.60 4Out 10.9 5.35 6 1/4In 12.8 5.45 6Out 10.5 5.35 8 1/4In 13.5 119. 18.7 5.45 8Catholyte 103.3 47.5 19.5 8.60 9______________________________________ *2 liters/min. Bleach Recycle - 6 volts, 20 amps?
TABLE IV*______________________________________Cell + 2 + 3 Na + TimeSolution Ferro g/l Ferri g/l Br g/l pH in Min.______________________________________Start-upAnolyte 12.2 119. 18.7 5.60 0Out 10.5 5.4 1.40In 11.8 5.5 1.50Out 10.9 121.5 18.55 5.35 3.10In 11.8 5.45 3.00Out 10.1 5.3 4.40In 10.5 5.4 4.30Out 9.3 5.3 6.10In 10.9 120. 18.55 5.35 6.0Catholyte 111.8 46.2 19.6 8.7 8.0Anolyte 10.1 123. 19.15 5.52 10.0______________________________________ *3 liters/min. Bleach Recycle - 6 volts, 20 amps
Based on data collected, the following equation was developed as applicable to electrolytic conversion of ferrocyanide to ferricyanide in accordance with this invention: ##EQU1## where J' = grams/liter/min ferrocyanide decrease;
E= % electrical efficiency ratio;
i= current in amps;
Q= flow rate (liters/min) through the cell;
Dt= Q/volume of the cell; and
-0.528 is equivalent of ferrocyanide oxidized per minute.
Electrolytic cells in accordance with the present invention for use in conversion of ferrocyanide to ferricyanide can be designed, using the above formula as a guide to size, current efficiency and rates of conversion. For example, a cell for 10 liter/min flow may be operated at 25-30 amps/ft 2 and up to 100 amps and under 10 volts D.C.
Variations in the above procedure include using potassium hydroxide as the catholyte rather than used bleach, in which event certain advantages occur. For example, it has been observed in the bleach catholyte that at high pHs there is a tendency for ferrocyanide to be converted to an amine which sometimes produces an odor. By using KOH as the catholyte, and introducing an oxidizing gas into the Contacogen, the amount of NaOH and KOH increases by diffusion of the cations through the membrane to react with the hydroxyl groups apparently formed by the reaction at the Contacogen. While this is not a proven working hypothesis, it does offer an explanation for the marked increase in pH in the catholyte, the absence of released hydrogen gas, and is not inconsistent with observed data.
The above system for oxidation of ferrocyanide to ferricyanide when used as an on-line bleach regeneration system for photographic processing may also be used jointly with a sensing system in which the pH of the regenerated bleach and the concentration of bromide ion are monitored and the bleach has added to it those materials needed to bring it to the proper concentration. While the system above has been explained on the basis of potassium or sodium ferrocyanide conversion to the ferricyanide state, it is understood that iron in an ethylene diamine tetracetic acid ligand could also be processed as described to bring the iron from a plus 2 to a plus 3 state.
With the system above described current densities of 30 amps/sq.ft. have been used without the release of hydrogen gas. Where the pH of the catholyte is above 12 and the catholyte is a mixture of ferro and ferricyanide, cyanate has been produced in the catholyte, and at high air or oxygen flows, primary amines are formed.
Another electrolysis system in which the present invention may be used is in the chlorate cell. Here there are several advantages considering the reactions said to take place at the cathode, e.g., hydrogen gas production, and the anode, e.g., primarily chlorine and oxygen. By use of a Contacogen, as described, at the cathode with the introduction of a gaseous oxidizing gas such as air or oxygen, then an oxidation-reduction reaction takes place at the situs of the Contacogen to convert the hydrogen gas into water or hydroxyl ion. The reaction of hydrogen in the presence of the Contacogen operates to remove hydrogen in gaseous form from the cell and thus greatly reduces the explosion hazard. The Contacogen may be placed in the cell, e.g., in the cathode compartment or the gas formed may be flowed to a reactor wherein the hydrogen gas is reacted with oxygen in the presence of a Contacogen and an aqueous medium.
It is also possible in accordance with the present invention to react the hydrogen of the cathode with the chlorine and oxygen of the anode to form water and hydrochloric acid which are returned to the cell for improved current efficiency as noted in U.S. Pat. No. 3,463,722, supra.
In the case of chlor-alkali cell especially the type in which the anolyte and catholyte are separated by a diaphragm, hydrogen is usually produced at the cathode, along with sodium hydroxide, and chlorine gas is produced at the anode. By using a Contacogen in the catholyte, or in gas receiving relation with the cathode generated gas, the unwanted hydrogen gas is easily eliminated by reaction with an oxidizing gas such as air or oxygen to produce water or hydroxyl ions.
A typical arrangement, in schematic form, for use in a chlorate unit in accordance with this invention is shown in FIG. 4 wherein an anode 90 is shown as spaced from a cathode 91, with a power supply 92 across the two electrodes. Supported above the electrodes and bridging them is a Contacogen support housing and gas collector 94 of polyethylene or the like receiving the hydrogen gas from the cathode and the oxygen and chlorine gas from the anode. Supported by a screen 95 within collector 94 is a Contacogen 96 which is wetted, but not flooded by the water vapor above the electrode. The screen may be of polyethylene of mesh size smaller than the Contacogen granules. As the released gases enter the collector 94 and come into contact with the Contacogen, hydrochloric acid and water are formed by the reaction between hydrogen gas, chlorine and oxygen, the reaction products being returned to the system. Depending on cell operating conditions or concentration, either oxygen, air or a reducing gas may be introduced through inlet 97, as needed, to effect reaction with the reactive species. While the electrodes are shown as anode and cathode, it is apparent that these could be bipolar electrodes with the facing portion being the cathode surface and anode surface, respectively.
In another form of the present invention suitable for use as a chlorate or chlor-alkali cell, as shown in FIG. 5, an anode 100 and cathode 102 are supported in spaced relation within a housing 105, current being supplied from a source 106. Surrounding the cathode 102 is a Contacogen support member 107 in the form of an annular polyethylene mesh basket so that the Contacogen is in close proximity to the cathode but electrically isolated therefrom. The mesh is of an open type, the openings in the mesh being smaller than the smallest particle of Contacogen 110 located in the basket 107. Air is introduced into the Contacogen bed through inlet pipes 112, although one may be used if desired, and oxygen may be employed rather than air. Depending on the nature of the catholyte, either hydroxyl ions or water may be formed by reaction between the oxidant gas and cathodically related reactive species. The oxygen produced at the anode may be collected and used as an input gas into the cathode area. As illustrated in FIG. 5, the Contacogen 110 is in contact with the electrolyte, but is not flooded thereby. Since the evolved gas is in an aqueous medium, the rate of reaction is quite low absent the Contacogen. By providing a Contacogen and an oxidant gas, troublesome hydrogen gas evolution is avoided.
The principles of the present invention may also be used in other electrochemical systems in which a gas is produced at one of the electrodes. For example in batteries of the alkaline metal type or of the rechargeable automotive type, using an aqueous electrolyte, the generation of electrical current results in the production of hydrogen gas which is usually vented. By the present invention, a small column of particulate Contacogen may be mounted to receive the hydrogen gas, reacted with oxygen in the form of air to form water which is returned to the battery system.
Various uses of the present invention in electrochemical and electrolytic systems will be apparent to those skilled in the art especially in connection with the handling of gaseous products of the electrochemical or electrolytic system.
While the methods herein described, and the forms of apparatus for carrying these methods into effect, constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise methods and forms of apparatus, and that changes may be made in either without departing from the scope of the invention which is defined in the appended claims.
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Gaseous products which tend to form at the anode or cathode of an electrolytic or electrochemical system in which the electrolyte is an aqueous medium may be converted into a reduction-oxidation reaction product through the action of a Contacogen. In such electrolytic systems, hydrogen is usually produced at the cathode and oxygen or other gas may be produced at the anode. By placing a Contacogen in gas receiving relation with the electrode at which a gas tends to be produced, and externally introducing a second gas into contact with the electrode gas and the Contacogen in the presence of an aqueous medium, the two gases enter into a reduction-oxidation reaction to produce a product which is electrolytically noninterferring. The Contacogen is particulate in nature and maintained in a static condition and forms the situs of reaction between the two gases in the presence of an aqueous medium. The Contacogen is wetproofed to prevent flooding thereof by the aqueous medium and operates to increase the rate of reaction between the gaseous reactants in the aqueous medium over the possible at room temperatures and pressures absent the Contacogen. Thus the present invention provides a novel method and apparatus for substantally eliminating one or more gaseous products formed in electrolytic systems having an aqueous medium as the electrolyte.
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BACKGROUND
[0001] 1. Field of Invention
[0002] This invention relates generally to methods of providing desalinated water.
[0003] 2. Related Art
[0004] Water, its location and abundance, is critical in determining where people will live. Water is needed for all the basic requirements of life—drinking; growing crops; commerce and industry; construction; landscaping; feeding domestic animals; and dozens of other purposes. It is so important that rivers have been dammed, aqueducts built to transport it from distant locations and wars fought to protect its continued ownership.
[0005] There are many arid and semi-arid areas in the World where there are ever increasing needs for usable water as the existing sources slowly decrease in abundance. Additionally, vast areas of usable land remain barren due to a lack of water.
[0006] The real problem is not a lack of water, since the Earth is covered by vast Oceans of water, large river systems, and polar ice caps, but a lack of water in regions where water is naturally not present in great abundance. The Earth's growing population requires more land for human occupation and more land to produce food to support that population. Water is needed to make the land useable by Man. Water is needed for drinking, crop irrigation, disposal of waste, and numerous other uses.
[0007] As the Human population in the World continues to increase, more and more radical plans are devised to obtain water. Rivers in the Northern latitudes are envisioned being re-directed by large pipes to transport the “wasted” water in wild rivers to populated areas in the South. Icebergs in the Artic and Antarctic are pictured being towed towards large cities to supply drinking water. The seawater in the Oceans is seen as an almost unlimited source of freshwater.
[0008] The most common method to solve the lack of water in places of need is to transport the water from areas of abundance to areas in need of the water. This solution is satisfactory until the demand for water eventually exceeds the ability to supply the water from these sites of abundance. As farther and farther sources of water are tapped for use by the growing populations, the cost of transporting the water and the degradation of the environment becomes so large that it ceases to be economical to supply water by this method.
[0009] At a “tipping point”, the cost of transporting fresh water becomes so expensive that it becomes economically feasible to extract usable water from the unusable saline water in the Oceans surrounding the continents.
[0010] Most current plans for obtaining abundant sources of freshwater are technologically possible but economically unfeasible. Currently, the only proposed “Big” plan that is reaching economic feasibility is Desalination of saline bodies of water. Desalination refers to any of several processes that remove excess salt and other minerals from water in order to obtain fresh water suitable for animal consumption, irrigation, industry, or human consumption. Desalination offers the ability to produce usable water at a reasonable cost, even though it is currently still too expensive in almost all situations except where the need is so great that cost is not the principal factor.
[0011] The first commonly used desalination method was distillation of seawater to produce fresh water. This method was very energy intensive so the cost of large-scale desalination production was impractical. Distillation of seawater is so cost prohibitive that it is only used in rather extreme cases; e.g., naval vessels, off-shore oil rigs, and isolated island outposts.
[0012] A more economical method of desalination is Reverse Osmosis. In simple terms, fresh water is produced by pumping a saline solution at high pressure into a pressure vessel divided by a semi permeable membrane that allows H 2 O to pass through the barrier while keeping most salutes on the other side of the barrier.
[0013] Osmosis is the natural process where water moves across a semi permeable membrane up a solution concentration gradient, from a less-concentrated solution (hypotonic) to a more-concentrated solution (hypertonic). This is accomplished without external energy sources, as the concentration of the solutions themselves drives the process. Indeed, energy is actually released during this process, and may drive other dependent processes in the natural world.
[0014] Reverse osmosis is the reverse of the natural process of osmosis, and is usually man-made. That is, a hypertonic solution is pressurized on one side of a semi-permeable membrane to between 350 and 2000 psi, forcing water through the membrane which acts as a very fine filter. A hypotonic solution is thus produced on the other side of the barrier. If pressure were removed, it is possible that osmosis would eventually return the two solutions to stasis.
[0015] Desalination with reverse osmosis requires a high pressure to be applied on the hypertonic side of the membrane, usually 2-17 bar (30-250 psi) for brackish water and 40-138 bar (600-2000 psi) for seawater. Sea water has around 24 bar (350 psi) of natural osmotic pressure which must be mechanically overcome to achieve reverse osmosis.
[0016] Currently, desalination is usually performed at or very near the source of inflow water. This includes pretreatment and initial filtration; pressurization; brine disposal; post-treatment of purified water; and re-pressurization for transport via pipeline. Reverse Osmosis facilities are often located in areas of fragile ecosystems or high population density, which causes problems due to the large volumes of brine which must be disposed of as well as the standard practice of introducing chemicals used to pre-treat inflow water, such as de-scaling additives, that are potentially harmful to the environment.
[0017] Crystallization of soluble salts may occur when either surface or ground water sources are used in membrane desalination processes such as Reverse Osmosis (RO). Concentrations of calcium, sulfate, bicarbonates and biological agents are usually present in natural sources of water. When attempting high recovery ratios (those exceeding 30%), at least some salts and organisms will be unable to transit the membrane. When salts exceed their saturation levels in the resulting brine, they begin to form crystals. The possible surface blockage of the membrane surface by this crystallization is known as ‘scaling’. In order to process water at a high recovery ratio, various chemicals (usually polymers) are added to source water. Some anti-scalants are specifically designed to be innocuous to the environment, while others may be extremely toxic. The selection of anti-scalants is application-specific based on source water composition and desired recovery ratio.
[0018] The Total Specific Water cost from a Collocated nuclear plant with Reverse Osmosis, and without transportation of fresh water or concentrate is $0.512 m 3 . However, the Specific Water cost from a Collocated nuclear plant and Reverse Osmosis, with conventional fresh water transportation via high pressure pipeline is $0.768 m 3 . This is still too high when compared with the cost of water from municipal sources which is often subsidized by government. Municipal water in Southern California is around $0.19/m 3 for home use and $0.03/m 3 for agricultural use. Reverse Osmosis shows promise as a method to obtain usable water, but the cost must be reduced to make it an economical alternative to current water supply methods.
[0019] The energy requirements of desalination reverse osmosis plants are large, but electricity can be produced relatively cheaply in areas with abundant oil reserves (e.g., Middle East). The desalination plants are often located adjacent to power plants.
[0020] There are circumstances in which it may be possible to use the same energy more than once. With cogeneration this occurs as energy drops from a high level of activity to an ambient level. Desalination processes, in particular, can be designed to take advantage of co-generation. For example, dual-purpose facilities can produce both electricity and water. The main advantage is that a combined facility can consume less net energy than would be needed by two separate facilities. This may be accomplished by two steps: using the heat energy normally carried away by cooling water in desalination, and reclaiming the power used to pump and pressurize water.
[0021] Reverse osmosis desalination is much more efficient when warmer water is used, with efficiency peaking at about 90° F., which is the regulatory limit in some areas on cooling water output temperature when exhausted into the sea by an industrial facility.
[0022] Power recovery at the output stage of desalination, the second way of saving energy, is made possible by the fact that reverse osmosis typically only consumes 2 to 3 bars of the input pressure. This means the output may remain in excess of 67 bars. Transformation of this potential energy into mechanical output can be accomplished by a Pelton wheel.
[0023] A Pelton wheel is one of the most efficient types of water turbines. It is an impulse machine that uses Newton's second law to extract energy from a jet of fluid. The pelton wheel turbine is a tangential flow impulse turbine, water flows along the tangent to the path of the runner. Nozzles direct forceful streams of water against a series of spoon-shaped buckets mounted around the edge of a wheel. Each bucket reverses the flow of water, leaving it with diminished energy. The resulting impulse spins the turbine. The buckets are mounted in pairs, to keep the forces on the wheel balanced, as well as to ensure smooth, efficient momentum transfer of the fluid jet to the wheel.
[0024] Since water is not a compressible fluid, almost all of the available energy is extracted in the first stage of the turbine. Therefore, Pelton wheels have only one wheel, unlike turbines that operate with compressible fluids. Pelton wheels are best for high head, low flow situations. It is usually better to seek a large pressure using a large head rather than to go for a fast flow rate.
[0025] The output of the Pelton wheel may be used to mechanically drive the pumping mechanism that is used to pressurize the input saline stream for desalination, or to generate electrical power.
[0026] Power recovery ratios on the order of 88% or better are possible, greatly reducing the power requirement for the desalination process, for which pumping may consume as much as 85% of the total power required (not counting the energy required to heat input water, which in cogeneration is obtained for free.)
[0027] A number of factors determine the capital and operating costs for desalination: capacity and type of facility, location, feed water, labor, energy, financing and concentrate disposal. Desalination methods control pressure, temperature and brine concentrations to optimize the water extraction efficiency. Nuclear-powered desalination might be economical on a large scale.
[0028] Critics point to the high costs of desalination technologies, especially for poor third world countries, the impracticability and cost of transporting or piping massive amounts of desalinated seawater throughout the interiors of large countries, and the byproduct of concentrated seawater, which some environmentalists have claimed is a major cause of marine pollution when dumped back into the oceans.
[0029] A study on current desalination technology noted that the costs are falling and generally usable for affluent areas that are proximate to oceans, so it may be a solution for some water-stressed regions. However, it is not appropriate for places that are poor, deep in the interior of a continent, or at high elevation; which unfortunately includes places with the biggest water problems.
[0030] Large coastal urban cities in the developed countries are increasingly looking at the feasibility of seawater desalination, due to its cost effectiveness when compared with other water supply augmentation options.
[0031] One of the main environmental considerations of ocean water desalination plants is the impact of the open ocean water intakes, especially when co-located with power plants. Many proposed ocean desalination plants initial plans relied on these intakes despite perpetuating huge ongoing impacts on marine life. In the United States, due to a recent court ruling under the Clean Water Act these intakes are no longer viable without reducing mortality by ninety percent of the plankton, fish eggs and fish larvae in the ocean water.
[0032] Regardless of the method used, there is always a highly concentrated waste product consisting of everything that was removed from the extracted fresh water. This is sometimes referred to as brine, which is also a common term for the byproduct of recycled water schemes that is often disposed of in the ocean. These concentrates are classified by the U.S. Environmental Protection Agency as industrial wastes. Reverse osmosis, for instance, may require the disposal of wastewater with salinity several times that of normal seawater. The benthic community cannot accommodate such an extreme change in salinity and many filter-feeding animals are destroyed when the water is returned to the ocean. This may present a similar problem further inland, where one needs to avoid ruining existing fresh water supplies such as ponds, rivers and aquifers. As such, proper disposal of concentrate needs to be insured during the design phases.
[0033] Concentrated seawater has the potential to harm ecosystems, especially marine environments in regions with low turbidity and high evaporation that already have elevated salinity. Examples of such locations are the Persian Gulf, the Red Sea and, in particular, coral lagoons of atolls and other tropical islands around the world. Because the brine is denser than the surrounding sea water due to the higher solute concentration, the ecosystems on the sea bed are most at risk because the brine sinks and remains there long enough to damage the ecosystems. It is capable of settling into depressions in the sea bed which function as a bowl. Dilution only occurs in the region where ordinary sea water and the concentrate are directly in contact, so that the ratio of surface area to brine mass comes into play during dilution. The larger the continual mass of submerged concentrate, the less surface area there is in ratio to that mass, and the slower acceptable dilution occurs. It is surmised in some studies that discharges of concentrate attending the normal operation of very large desalination plants may continue to extend undiluted masses of hyper salinity along the bottom of a sea almost as long as the plant remains in operation.
[0034] The discharge of the salt concentrate from a desalination plant is harmful to the environment. The influx of freshwater causes an influx in population growth near the power plant. Reverse Osmosis requires a large amount of energy to drive the operation (˜3.5 to 4.5 KWH/m 3 ) which accounts for $0.14 to $0.18 per m 3 or $170 to $225 per acre-foot. The typical desalination plant transports only the treated fresh water from the plant, which requires high pressure pumping for both the desalination process and transporting the fresh water. This requires the duplication of both the energy and equipment. The brine is not transported from the facility, and is discharged locally into the sea. Power recovery at the outflow point of freshwater pipelines is not done, which means that the power required to pressurize the freshwater pipeline is effectively lost.
[0035] Current Reverse Osmosis facilities, even with power recovery features, fail because they waste power by pressurizing the water twice, once for Reverse Osmosis, and again for freshwater pipeline transport; do not transport brine that creates environmental problems by requiring local disposal; and do not attempt power recovery following pipeline transport.
SUMMARY
[0036] The disclosed desalination method, associated arrangement of Reverse Osmosis modules, economic value of the resulting products, and energy recovery comprises an efficient process to desalinate brackish, salt, or otherwise contaminated water to produce usable water.
[0037] Disclosed is an economical and environmentally responsible method of desalination and delivery of freshwater, concentrate, and electrical power to a site removed from the saline water source. Freshwater, concentrate, and power can be delivered by pipeline to multiple locations along the route and/or at the endpoint, thus distributing the beneficial aspects while minimizing the environmental impact of desalination facilities.
[0038] The disclosed system transports both fresh water and concentrate while maintaining the thermal advantage of outflow cooling water from an industrial facility such as a power generation plant. In doing so, fresh water is delivered to regions in need of water and the concentrate arrives where it can be profitably processed or used rather than discarded, and without incurring additional power requirements for transportation because of the economic equation of a high-bulk, low-value commodity.
[0039] The disclosed method produces freshwater from a saline water source and delivers it economically a distance away from the power plant.
[0040] Another disclosed method is the economical transport of fresh water by recovering the power used to pressurize the pipe by using a Pelton wheel.
[0041] Another disclosed method is the use of excess water flow to clean the semi-permeable membrane used for reverse osmosis.
[0042] Other objects, features, embodiments and advantages of the present invention will become apparent from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] List of drawings
[0044] FIG. 1 is a schematic view of the overall scope of the disclosure.
[0045] FIG. 2 is a schematic view of a single reverse osmosis unit where a freshwater outflow is produced and the concentrate is returned to the water transportation line. This is an inline desalination unit.
[0046] FIG. 3 is a schematic view of a single reverse osmosis unit where a freshwater outflow is produced and the concentrate is passed through a pelton wheel before being used for a commercial purpose. This is a terminal desalination module.
[0047] FIG. 4 is a schematic view of multiple reverse osmosis units in series where final concentrate outflow is passed through a pelton wheel before being used for a commercial use. In this example, each R/O unit is designed to accept the flow, pressure, and salinity of the preceding unit. These are mainly inline desalination modules, but the final module could be a terminal desalination module.
[0048] FIG. 5 is a schematic view of a single reverse osmosis unit where the freshwater outflow, concentrate outflow, and electricity are delivered to same location.
DETAILED DESCRIPTION
Definitions
[0049] As used herein, agriculture water is water that meets the standards for agriculture use (either for irrigation or animals) and may not meet the standards for human consumption due to taste, composition, or both.
[0050] Anti-scalant—a chemical (usually a polymer) that is added to the source water used for reverse osmosis to either prolong the onset of crystallization by extending the solubility of salts that are most offensive in the water source, or minimize the tendency of the salt to cling to the membrane surface once crystallization occurs, thus allowing water flow to flush them out of the RO device.
[0051] Brackish water—0.05%-3% salinity.
[0052] Brine—>5% salinity
[0053] Brine disposal—long-term disposition of the high-salinity remainder following extraction of fresh water through membrane extraction, such as, reverse osmosis.
[0054] Caustics—base catalysts, such as, potassium hydroxide or sodium hydroxide, used to promote chemical reactions.
[0055] Cogeneration facility—a facility added to an existing industrial plant in order to produce a different product than the original plant produces. An example is a desalination facility that produces fresh water by accepting discharged heated cooling water from a nuclear power plant.
[0056] Collocated facility—a cogeneration facility that is physically located adjacent or immediately next to or even within another facility.
[0057] Concentrate—also called brine; >5% salinity.
[0058] Cooling towers—structures which are intended to facilitate evaporative cooling for an industrial facility.
[0059] Cooling Water (CW) system—water circulation system by which an industrial facility dissipates excess heat. There are two types: pass-through cooling, and evaporative cooling. Pass-through uses a nearby open water source as a heat sink, and passes through all of the excess heat by heating large amounts of intake water and discharging it back into the water source. Evaporative cooling utilizes cooling towers to dissipate at least some of the excess heat into the atmosphere.
[0060] Dechlorination chemicals—chemicals that counter or remove chlorine from water are called dechlorination chemicals.
[0061] Desalination—a process that converts seawater or brackish water to fresh water or an otherwise more usable condition through removal of dissolved solids; removing salts from ocean or brackish water by using various technologies; production of fresh water by removing salt from seawater or brackish water through the application of energy; or any of several processes that remove the excess salt and minerals from water in order to obtain fresh water suitable for animal consumption or for irrigation.
[0062] Desalination system—the equipment, pipes, pumps and other items combined to accomplish desalination.
[0063] Dispersant—an additive which keeps fine particles of insoluble materials in a homogeneous solution. Hence, particles are not permitted to settle out and accumulate.
[0064] Distillation—a process of heating water until it evaporates as steam leaving behind bacteria, minerals, trace amounts of metals, sodium chloride, organic chemicals and nitrate, and subsequently condensing the steam into water.
[0065] Electrical Grid—the electrical distribution network of any community.
[0066] Electrical Power Exchange—an electrical generation concern, retail electrical exchange, and/or wholesale electrical exchange who provides electrical power to itself or to one or more customers. It is not necessary for an Electrical Power Exchange to generate electricity in order to exchange it, so this term is intended to include any entity selling and/or contracting for electrical power.
[0067] Evaporation pond—a shallow pond designed to produce salt from sea water. The seawater is fed into large ponds and water is drawn out through natural evaporation which allows the salt to be subsequently harvested.
[0068] Fresh water—a general term for “sweet water”, agricultural (ag water), potable (drinking water), or to any other water that contains <0.5% salt and minerals, such as, most pond and lake water.
[0069] High Pressure Pump—a pump that has a working output pressure exceeding 1000 psi.
[0070] Hypersaline—water with a high concentration of salt, greater than the ionic content of seawater.
[0071] Hyper-saline agriculture water—ag water containing from 5% salts to saturation (˜27%).
[0072] Inline desalination module—a desalination unit that does not terminate the transportation system, but is either inserted into or fed by the water transportation pipeline.
[0073] MegaWatts electric (MWe)—one million watts of electric energy.
[0074] MegaWatts thermal (MWt)—one million watts of thermal (heat) energy.
[0075] Near saturation—a point at which liquid water will hold minerals in solution, but is within 7 percentage points of saturation.
[0076] Non-potable water—unsafe or unpalatable to drink because in contains objectionable pollution, contamination, minerals, or infective agents.
[0077] Offsite Location—a location that is not collocated [not close to or at the same place] with the Power plant.
[0078] Pelton wheel—also called a Pelton turbine, an efficient type of water turbine; an impulse machine (uses Newton's second law to extract energy from a jet of fluid).
[0079] Pipeline—a pressurized pipe through which bulk liquids are transported.
[0080] Potable water—clean and free from harmful chemicals and disease-carrying microbes.
[0081] Power recovery—process by which power that has been expended is subsequently recovered, usually to be directed elsewhere. An example is converting the energy required to pressurize water from the resulting high pressure stream to rotational energy by directing that stream to strike the blades of a Pelton wheel. The rotational energy thus obtained by power recovery may be used for another purpose, such as, turning an electrical generator or another water pump.
[0082] Pressurization—exerting force in order to create pressure in a fluid or gaseous medium. An example is creating water pressure within a piping system with a water pump.
[0083] Pre-treat inflow water—process of initial straining, coarse filtering, or the addition of chemicals to inflow water in order to facilitate it's use. An example is the inflow water in industrial cooling loops that utilize sea water may be pre-treated by sand-filtration to remove most organisms, and may additionally have chemicals added to reduce the tendency to foul pumps and fittings with mineral deposits. Another example is a Reverse Osmosis desalination facility may pre-treat inflow water with anti-scalants to delay the onset of organic and inorganic deposits blocking the membrane surfaces, which necessitates membrane maintenance and possible replacement.
[0084] Pre-treated seawater—inflow seawater that is pre-treated.
[0085] Pretreatment—process of treating water prior to introduction to a cooling or desalination facility.
[0086] Re-pressurization—increasing the water pressure, after the pressure loss during desalination, to the pressure within the pipeline so that the outflow can be returned to the pipeline transportation system.
[0087] Reverse Osmosis (RO)—a process whereby dissolved salts, such as sodium, chloride, calcium carbonate, and calcium sulfate may be separated from water by forcing the water through a semi-permeable membrane under high pressure. The water diffuses through the membrane and the dissolved salts remain in solution on the input side of the membrane.
[0088] RO desalination module—the combination of equipment, pumps, pipes, treatment processes and other items used to obtain saline water from the transportation pipe to produce freshwater and concentrate, and power recovery, if desired.
[0089] Saturation—the point at which a solution of a substance can dissolve no more of that substance. This point, the saturation point, depends on the temperature and pressure of the liquid, as well as, the chemical nature of the substances involved.
[0090] Terminal desalination module—the last desalination module on the transportation route.
[0091] Pretreatment for pipeline transportation occurs as or before inflow water is admitted to the transportation system. Pretreatment for desalination can be performed then, or within the pressurized pipeline, so any additional pretreatment can be deferred and tailored to a desalination method, in cases where more than one desalination method is located along a single pipeline. Additionally, pretreatment must be compatible with the use of the concentrate at the outflow(s). The inflow can be cooling water from an industrial facility, e.g., a power generation plant. These facilities usually require MF pre-treatment or the equivalent to protect the equipment from scaling and fouling.
Features
[0092] 1 . Water transportation line
[0093] 2 . Reverse osmosis unit
[0094] 3 . Freshwater outflow
[0095] 4 . Pelton wheel
[0096] 5 . Electricity power
[0097] 6 . Low pressure concentrate outflow
[0098] 7 . High pressure warm saline water inflow
[0099] 8 . Pressure regulator
[0100] 9 . Optimum pressure warm saline water outflow
[0101] 10 . High pressure Concentrate outflow
[0102] 11 . High pressure pump
[0103] 12 . Reverse osmosis unit
[0104] 13 . Freshwater outflow
[0105] 14 . Water transportation line
[0106] 15 . Optimum pressure warm saline water outflow
[0107] 16 . Reverse osmosis unit
[0108] 17 . Freshwater outflow
[0109] 18 . High pressure Concentrate outflow
[0110] 19 . Pelton wheel
[0111] 20 . Low pressure concentrate outflow
[0112] 21 . Mechanical power
[0113] 22 . Power recovery—electric generator
[0114] 23 . Electricity power
[0115] 24 . Optimum pressure warm saline water outflow
[0116] 25 . Reverse osmosis unit
[0117] 26 . Freshwater outflow
[0118] 29 . High pressure Concentrate outflow
[0119] 30 . Pelton wheel
[0120] 31 . Low pressure concentrate outflow
[0121] 32 . Mechanical power
[0122] 33 . Power recovery—electric generator
[0123] 34 . Electricity power
[0124] 35 . Water transportation line
[0125] 36 . High pressure warm saline water inflow
[0126] 37 . Pressure regulator
[0127] 38 . Optimum pressure warm saline water outflow
[0128] 39 . Reverse osmosis unit
[0129] 40 . Freshwater outflow
[0130] 41 . High pressure Concentrate outflow
[0131] 42 . Pelton wheel
[0132] 43 . Low pressure concentrate outflow
[0133] 44 . Mechanical power
[0134] 45 . Power recovery—electric generator
[0135] 46 . Electricity power
[0136] Referring to FIG. 1 showing a preferred embodiment, a power plant is located next to a saline body of water and uses the body of water as a source for the cooling water for the power plant. A part or all of the cooling water is diverted from it's normal disposition for use in the invention. Pretreatment for pipeline transportation occurs at this time. Pretreatment for desalination can be performed within the pressurized pipeline, so any additional pretreatment can be deferred and tailored to a desalination method, in cases where more than one desalination method is located along a single pipeline. Additionally, pretreatment must be compatible with the use of the concentrate at the outflow(s). The diverted cooling water goes through a high pressure pump 11 and is directed to a water transportation line 1 to deliver the high pressure warm saline water 7 to a distant site where the high pressure warm saline water 7 is used in a reverse osmosis 2 system to produce freshwater 3 and concentrate 10 . The freshwater 3 can be of various quality standards depending on its intended use. The freshwater 3 could be used for drinking water or municipal water in communities, agriculture and farming or industrial and commercial. At the final destination, the high pressure warm saline water 7 is used to produce freshwater 3 and the concentrate 10 , which is still at high pressure, is directed through a pelton wheel 4 to recover the energy (mechanical power 14 ) retained in the pressure. The concentrate 6 , after the pelton wheel 4 , is at a low pressure and available for the multitude of commercial uses for brine, one of which is salt production in evaporation ponds. The mechanical energy 14 extracted by the pelton wheel 4 is used to move an electric generator 15 . The recovered electricity 5 can be used at the distant site for any available need, or sold.
[0137] FIG. 2 shows a schematic of the various steps and products from an inline desalination module along the transport route according to one embodiment. A high pressure warm saline water inflow 7 comes off the water transportation line 14 and enters a pressure regulator 8 to lower the water pressure to a sufficient, preferably optimum, pressure for reverse osmosis unit 12 . Optionally, a venture pump can be used to draw additional saline or contaminated water into the transportation system while simultaneously lowering the pressure to the optimum, perhaps assisted by a regulator. The pressurized warm saline water 9 enters the reverse osmosis unit 12 and produces a freshwater outflow 13 and a concentrate (brine) outflow 10 . The concentrate outflow is still at high pressure, although it has lost some pressure during the reverse osmosis process. The concentrate outflow 10 goes to a high pressure pump 11 to return the concentrate to the same pressure as the water transportation pipe 14 and enters the water transportation pipe 14 to continue onto the final destination.
[0138] FIG. 3 shows a schematic of an embodiment of a single reverse osmosis system with power recovery which is a terminal desalination module. It produces both a freshwater outflow 17 and a low pressure concentrate outflow 20 . The optimum pressure warm saline water inflow 15 enters the reverse osmosis unit 16 . The reverse osmosis unit 16 produces a freshwater outflow 17 and high pressure concentrate outflow 18 . The high pressure concentrate outflow 18 passes through a pelton wheel 19 to recover the energy in the high pressure concentrate 18 by producing a low pressure concentrate outflow 20 . The mechanical energy 21 from the pelton wheel 19 is used to move an electric generator 22 to produce electricity 23 .
[0139] FIG. 4 shows a schematic of an embodiment of multiple reverse osmosis units in series along a transportation line. The optimum pressure warm saline water inflow 24 a enters the first reverse osmosis unit 25 a . The pressure may have been optimized by the use of a regulator and/or a venture pump, or the first reverse osmosis unit 25 a may be designed to accept full transportation flow and pressure.
[0140] The optimum pressure saline water inflow 24 a enters the first reverse osmosis unit 25 a . The reverse osmosis unit 25 a produces a freshwater outflow 26 a and the optimum pressure inflow to the next stage 24 b . The first reverse osmosis unit 25 a does not extract the full quantity of freshwater 26 . The concentrate outflow is transported to the next reverse osmosis unit 25 n in series. This reverse osmosis unit extracts another quantity of freshwater 26 n , which is still below the full amount. This process continues until the full amount of freshwater 26 has been extracted. The high pressure concentrate outflow 29 from the last reverse osmosis unit 25 n in the series passes through a pelton wheel 30 to recover the energy in the high pressure concentrate 29 by producing a low pressure concentrate outflow 31 . The mechanical energy 32 from the pelton wheel 30 is used to move an electric generator 33 to produce electricity 34 .
[0141] FIG. 5 shows a schematic of an embodiment of a reverse osmosis system where the freshwater outflow, low pressure concentrate and electricity is delivered to the same location, yet it is an inline desalination module. A high pressure warm saline water inflow 36 comes off the water transportation line 35 and enters a pressure regulator 37 to lower the water pressure to the optimum pressure for reverse osmosis unit 39 . The optimum pressure warm saline water 38 enters to the reverse osmosis unit 39 and produces a freshwater outflow 40 and a high pressure concentrate (brine) outflow 41 . The high pressure concentrate outflow 41 passes through a pelton wheel 42 to recover the energy in the high pressure concentrate 41 by producing a low pressure concentrate outflow 43 . The mechanical energy 44 from the pelton wheel is used to move an electric generator 45 to produce electricity 46 , which can be delivered for municipal, industrial, or agriculture uses.
[0142] The fact that the temperature of the cooling water has been increased above ambient (often around 90° F.) is extremely helpful, but not required for desalination. The use of the warm water effluent makes it economical, which otherwise would require enormous amounts of energy, to take advantage of the increased production obtained with large volume desalination.
[0143] Once the water has been warmed, given the pressures within the pipeline and the relatively small surface area ratio to product mass of a large diameter pipe, only moderate insulation is needed to limit thermal losses or gains during transport.
[0144] The Power used to pressurize the pipeline is ultimately recoverable. The recovery potential represents more than 100% of the total power requirement of a typical Reverse Osmosis module. Since most Reverse Osmosis units do not require more than 68 bars to operate and a pipeline is typically pressurized at 80 to 120 bars, the excess pressure (=power) is sold or scavenged. The power recovery can be done with a Pelton Wheel and a generator, or other power recovery technologies.
[0145] The pressure within the pipeline, in the range of 80 to 120 bars, exceeds the threshold needed for Reverse Osmosis/MF. The greater the pressure, the greater the potential flow rate and power content of the pipeline, the greater the potential fresh water recovery percentage, and the more flexibility in future adaptations for increasing or decreasing fresh and concentrate delivery requirements.
[0146] These factors enable the use of multiple Reverse Osmosis units powered primarily by pipeline pressure along the pipeline route, even given normal pressure losses due to hydraulic friction, possible elasticity of the pipeline, and the gains/losses attributable to changes in elevation. However, multiple desalination unit taps are not essential; it is possible to construct a single desalination unit anywhere along the pipeline route. Following any desalination unit, is possible to continue a concentrate-only pipeline retaining much of the original pressure to another destination, at which time power recovery may be applied as the concentrate is returned to near-ambient pressures. This permits delivery of fresh water and concentrate to diverse locations.
[0147] Reductions in the size of the pipeline following each desalination unit may be minimized by restricting the flow at key points along the pipeline route, such as immediately after a desalination unit. Data collection the length of the pipeline could enable automatic flow restriction mechanisms, and/or provide decision-making information for manual control. This permits near-uniform dimensions within the pipeline, retaining maximum future flexibility.
[0148] Pressure controls also allow taking Reverse Osmosis modules off-line for maintenance without shutting down upstream and downstream modules.
[0149] The cost savings of forgoing the flexibility of an over-all flow restriction mechanism and savings derived by reducing pipeline diameters must be weighed against the possibility of future demands that might outstrip the flexibility of a minimally-designed system, whose useful lifetime if typical of a high-pressure pipeline exceeds 25 years.
[0150] It may not be practical to return power generated by the energy recovery system directly to the high pressure pump at the pipeline head. Rather, the power may be phase-adjusted and fed into the local utility access point available to the final Reverse Osmosis unit, similar to a power generation windmill farm or grid-tied photovoltaic system. By selling the generated power to the local utility, the power consumed at the pipeline head is logically rather than physically offset. While it may not be the case that the same utility or generation mechanism is supplying power to both the head and tail of the pipeline, this is irrelevant if the entity managing the head of the pipeline is cooperative with or even the same entity that is managing the tail, so that the costs can be balanced.
[0151] Regarding the relative value of electricity at the head and tail, it is often the case that customer-generated power may be sold to the grid at rates that exceed the customers average use rate. Given these reasonable caveats, the net power consumption of the improved desalination process is greatly reduced by utilizing energy recovery, which is estimated to be on the order of 82 to 88% when using a Pelton wheel. Given hydraulic friction losses of 3% per Reverse Osmosis unit and estimating 12% for an arbitrary pipeline length, the over-all power consumption of the pressurization and pumping unit might be reduced by approximately 70%. It is to be expected that cost offsets will be at least commensurate.
[0152] The power consumption is reduced by pipelining saline water and generating fresh water locally as opposed to performing desalination at the head and pipelining fresh water to be delivered locally. The same pressurization that is used to charge the pipeline is used to provide most of the power to the Reverse Osmosis units on the line. The savings approaches 86% of the total power required for high-pressure pumping, since pipeline power is rarely recovered in the conventional method. Indeed, given that pipeline pressures exceed Reverse Osmosis requirements, it is possible that normal Reverse Osmosis unit power requirements will be completely absorbed by power recovery of the pipeline pressure.
[0153] Additional efficiency arises due to a side effect of introducing multiple Reverse Osmosis units in a single saline pipeline. No single unit is tapping a maximum amount of fresh water from the line, so that the flow through each Reverse Osmosis can be designed to be relatively high, on the order of ‘n’ times the extraction efficiency required at each unit. That is, assuming F is the total amount of water introduced to the new desalination process system; unit n actually requires just F/n of the total flow, if operating at maximum efficiency. Running a Reverse Osmosis module at maximum efficiency tends to increase maintenance requirements for the membranes and shorten their useful life. If, however, F is the flow through n, and the total amount of fresh water required is 1/n of max, the efficiency of unit n need only be 1/n of the theoretical maximum, and the extra flow will exert a scrubbing effect on the membranes. Conversely, we could use 1/n of the membrane surface area that might otherwise be used for a single Reverse Osmosis unit, which would also reduce the fresh water yield from the line. In the latter case, both the acquisition and maintenance costs of each Reverse Osmosis module are reduced to a factor of 1/n.
[0154] Variable flow restriction within the new desalination process system may address the issue of future expanded capacity economically. By operating with maximum flow restriction, the eventual capacity of the system can be increased within the range of a variable set of HP pumps coupled with the flow restriction mechanism, both of which are designed to operate within high and low capacity limits. Conversely, occasional replacement of the pumps need not necessitate replacement of either the pipeline or other elements of the new desalination process. It is thus possible to actually add or subtract capacity of existing individual Reverse Osmosis modules, to physically add modules to the pipeline, or even to adapt to a new desalination or pumping technology without modifying the overall desalination process.
[0155] Finally, the discharge of concentrate may be anywhere along the pipeline, assuming the final discharge follows the final (or sole) desalination unit. By waiting until a favorable location for power recovery, a geographically favorable location is insured to release the concentrate profitably. Gravity feed can be used to reduce the need for pumping the concentrate and fresh water product for industrial and farm uses by performing desalination at relatively high elevation.
[0156] In one embodiment, the temperature of the cooling water is raised about 10° C. above ambient. In another embodiment, the temperature of the cooling water is raised about 15° C. above ambient. In another embodiment, the temperature of the cooling water is raised >15° C. above ambient.
[0157] In one embodiment the temperature of the saline water in the pipe is around 40° C. In another embodiment the temperature of the saline water in the pipe is between 30° C. and 45° C.
[0158] In one embodiment the cooling water is pre-treated. In another embodiment the cooling water is treated with microfiltration. In another embodiment the cooling water is treated with an anti-scaling agent.
[0159] In one embodiment the concentrate industries are not established, and the concentrate and fresh water are sold at municipal rates with no premium.
[0160] In one embodiment the saline water is pre-treated with Acids. In one embodiment the saline water is pre-treated with hydrochloric acid. In one embodiment the saline water is pre-treated with sulfuric acid.
[0161] In one embodiment the saline water is pre-treated with Bases. In one embodiment the saline water is pre-treated with sodium hydroxide (NaOH). In one embodiment the saline water is pre-treated to ≧8 pH.
[0162] In one embodiment the saline water is pre-treated with dechlorination chemicals. In one embodiment the saline water is pre-treated with Sodium bisulfate.
[0163] In one embodiment the saline water is pre-treated with Anti-scalants. In one embodiment the saline water is pre-treated with Dispersants. In one embodiment the saline water is pre-treated with an anti-scalant or dispersant polymer.
[0164] In one embodiment the reverse osmosis module has a power recovery system using a Pelton Wheel. In one embodiment the reverse osmosis module is equipped with a high-pressure pump and a power recovery system using a Pelton Wheel.
[0165] In one embodiment the concentrate is used to produce salt. In one embodiment the concentrate reduces the area needed for salt production to approximately one sixth. In one embodiment the concentrate reduces the time needed for salt production to approximately one sixth.
[0166] In one embodiment the concentrate is sold as brine.
[0167] In one embodiment the concentrate is used to produce magnesium chloride. In one embodiment the concentrate is used to produce magnesium sulphate. In one embodiment the concentrate is used to produce potassium chloride. In one embodiment the concentrate is used to produce gypsum.
[0168] In one embodiment the Power Plant and the Reverse Osmosis unit are not located at the same facility. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧0.5 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧1 mile a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧2 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧3 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧4 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧5 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧10 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧15 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧20 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧25 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧50 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧75 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧100 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧125 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧150 miles a part. In one embodiment the Power Plant and the Reverse Osmosis unit are ≧200 miles a part.
[0169] In one embodiment there is one Reverse Osmosis unit between the Power Plant and the final production of concentrate. In one embodiment there are >1 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧2 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧3 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧4 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧5 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧10 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧15 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧25 Reverse Osmosis units between the Power Plant and the final production of concentrate. In one embodiment there are ≧50 Reverse Osmosis units between the Power Plant and the final production of concentrate.
Cost Considerations
[0170] Cost is a dynamic and rapidly changing factor; however, the trend in Reverse Osmosis is declining costs. Reverse Osmosis technology produces fresh water to about $0.5 m 3 , or $616.74 per acre foot, approximately 2.5 times the current open market cost of municipal water in California. This trend alone, particularly given the contrasting increases in water costs from other sources in Southern California, could make conventionally-derived Reverse Osmosis water competitive with other sources within the decade. However, with this new desalination process we do not have to depend on future developments in order to make desalination reasonably competitive today; we have only to ensure power is distributed economically between Reverse Osmosis and transportation; that power recovery is implemented; and that we produce a product (concentrate or brine) that can be shown to be sufficiently valuable to offset the costs of desalination.
EXAMPLE 1
[0171] A industrial plant is located on the shore of a saline or otherwise polluted body of water. The industrial plant can use type of fuel or method that produces heat for use during the power generating process. Water is pumped from the body of water and used during the cooling stage of the power generating process. During the cooling process, excess heat from the power generating process, is transferred to the body of water by conduction.
[0172] The heated water is transferred some distance from the industrial plant to a location in need of water for human consumption, agricultural or industrial use. The heated water is used in a method comprising the steps of:
1. obtaining water from a saline or otherwise polluted body of water 2. passing the water through a cooling system associate with an industrial plant to 3. raise the water temperature of the water above ambient 4. pressuring the heated water and transporting the water through a pipeline transportation system offsite from the industrial plant 5. taking a portion of the heated water, passing it through at least one offsite desalination system, generating usable water, and producing a hyper saline or otherwise contaminate-rich concentrate 6. optionally mixing the concentrate with the remaining heated water and transporting combined water to final destination 7. generating electrical power by reducing the pressure in pipe to ambient and recovering the power with a Pelton wheel or other power recovery technology 8. delivering concentrate for a commercial use to a final local.
EXAMPLE 2
Nuclear Cogeneration with an Improved Desalination
[0181] An industrial cogeneration power plant with two units is located on the shore next to a saline water source. Each unit has a 32% efficiency, which means that 68% of the generated heat is lost to the cooling water. The two units combined generate 6,600 MWt which produces 2,200 MWe. Thus, 4,400 MWth is lost to the cooling water. The amount of cooling water flowing through the Cooling Water system of each reactor unit is about 1.2 Billion gals, or a total of 2.4 Billion per day. The total Cooling Water discharge per year is about 2.7 Million acre-feet.
[0182] The water is discharged from the Cooling Water system at a temperature around 90° F. This temperature is very near the optimal pre-heating temperature for the Reverse Osmosis desalination modules.
[0183] The large flow of pre-treated, heated water from the cooling water system is pressurized and transported down the pipeline. The imparted pressure is retained, and thermal coupling adjustments are implemented to slightly reduce the flow but increase the heat of the outflow when pipeline(s) handle the entire outflow.
[0184] The Cooling Water system has a bypass mechanism, which is usually closed, to shunt the water back into the saline body of water in case the pipeline(s) are shut down and the water is re-routed back through the diffusers.
[0185] The pressure of the Cooling Water system is coupled with an additional high-pressure pump to increase the water up to at least the pressure required by a high-pressure pipeline. The heated treated water is transported by an insulated, high-pressure pipeline to an inland destination.
[0186] The pressure from the pipeline is used to power the desalination plant(s) along the route and/or at the pipeline terminus. Fresh water is extracted and allowed to flow into a water treatment plant for calcification and other post-treatment. Post-treatment varies depending on the intended use of the fresh water.
[0187] The concentrate exits the Reverse Osmosis unit, still at high pressure, and is used to power a Pelton wheel, whose rotational torque is used to power a generator. The concentrate returns to near-ambient pressure, and flows downhill or is pumped to industrial and farm consumers where it is economical to use. The output of the generator is sold to the local utility company as excess power or returned to the pumping station, offsetting the cost of the power consumed by the high-pressure pump at the pipeline head.
[0188] The locations of the Pelton wheels and concentrate outflow delivery, as well as fresh water delivery, are selected to permit gravity distribution where possible and easy access to the electrical grid. The Pelton wheel, concentrate outflow, and the desalination facility are co-located, but this is not a requirement.
[0189] The presence of power, fresh water product, and concentrate promotes the establishment of local industries which consume the concentrate. These industries will invigorate rail heads, trucking companies, supply companies and other infrastructure enhancements.
[0190] Additionally, Inland community development and expansion is enabled by the presence of additional water and power.
[0191] Another advantage is a virtually unlimited source of saline water along the pipeline route for firefighting, saline pools and saline landscaping, as well as, additional Reverse Osmosis modules. Branch outlets are present to route feeder pipe lines or open transport mechanisms for any of these purposes.
[0192] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, means, methods and/or steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the invention is intended to include within its scope such processes, machines, means, methods, or steps.
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An economical and environmentally responsible method of desalination and delivery of freshwater, concentrate, and electrical power to a site removed from the saline water source. Freshwater, concentrate, and power can be delivered by pipeline to multiple locations along the route and/or at the endpoint, thus distributing the beneficial aspects while minimizing the environmental impact of desalination facilities.
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BACKGROUND OF THE INVENTION
[0001] This invention relates in general to vehicle wheels and in particular to an improved method for producing a full face fabricated vehicle wheel.
[0002] A conventional fabricated vehicle wheel is typically of a two-piece construction and includes an inner disc and an outer “full” rim. The disc can be cast, forged, or fabricated from steel, aluminum, or other alloys, and includes an inner annular wheel mounting portion and an outer annular portion. The wheel mounting portion defines an inboard mounting surface and includes a center pilot or hub hole, and a plurality of lug receiving holes formed therethrough for mounting the wheel to an axle of the vehicle. The rim is fabricated from steel, aluminum, or other alloys, and includes an inboard tire bead seat retaining flange, an inboard tire bead seat, an axially extending well, an outboard tire bead seat, and an outboard tire bead seat retaining flange. In some instances, a three-piece wheel construction having a mounting cup secured to the disc is used. In both types of constructions, the outer annular portion of the disc is secured to the rim by welding.
[0003] A full face fabricated vehicle wheel is distinguished from other types of fabricated wheels by having a one-piece wheel disc construction. In particular, the full face wheel includes a “full face” disc and a “partial” rim. The full face-disc can be formed cast, forged, or fabricated from steel, aluminum, or other alloys. The full face disc includes an inner annular wheel mounting portion and an outer annular portion which defines at least a portion of an outboard tire bead seat retaining flange of the wheel. The wheel mounting portion defines an inboard mounting surface and includes a center pilot or hub hole, and a plurality of lug receiving holes formed therethrough for mounting the wheel to an axle of the vehicle. The partial rim is fabricated from steel, aluminum, or other alloys, and includes an inboard tire bead seat retaining flange, an inboard tire bead seat, an axially extending well, and an outboard tire bead seat. In some instances, the outboard tire bead seat of the rim and the outer annular portion of the disc cooperate to form the outboard tire bead seat retaining flange of the full face wheel. In both types of constructions, the outboard tire bead seat of the rim is positioned adjacent the outer annular portion of the disc and a weld is applied to secure the rim and the disc together.
SUMMARY OF THE INVENTION
[0004] This invention relates to an improved method for forming a full face fabricated vehicle wheel and includes the steps of: (a) providing a disc blank formed from a metal material; (b) subjecting the disc blank to a metal stamping operation to produce a partially formed non-bowl shaped full face wheel disc having at least one stamped pocket formed therein; (c) forming at least one decorative window in the partially formed full face wheel disc; (d) coining a back side of the window in the partially formed full face wheel disc; (e) trimming an outer edge of the partially formed full face wheel disc to a predetermined diameter; (f) forming a center hub hole in the partially formed full face wheel disc; (g) subjecting the partially formed full face wheel disc to one or more final metal forming operations to form at least one of an outer flange and a plurality of lug bolt mounting holes in the partially formed wheel disc so as to produce a finished full face wheel disc; and (h) securing the full face wheel disc to a preformed wheel rim to produce the finished full face fabricated vehicle wheel.
[0005] Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a block diagram illustrating a prior art sequence of steps for producing a prior art full face fabricated vehicle wheel.
[0007] [0007]FIG. 2 is a cross sectional view of a disc blank for use in producing the prior art full face fabricated vehicle wheel.
[0008] [0008]FIG. 3 is a cross sectional view showing the initial stamping of the disc blank into a generally bowl shaped wheel disc.
[0009] [0009]FIG. 4 is a cross sectional view showing the intermediate stamping of the bowl shaped disc to produce a partially formed wheel disc.
[0010] [0010]FIG. 5 is a cross sectional view showing the forming of the windows in the partially formed wheel disc.
[0011] [0011]FIG. 6 is a cross sectional view showing the trimming of the outer diameter of the partially formed wheel disc.
[0012] [0012]FIG. 7 is a cross sectional view showing the forming of the hub hole and lug bolt mounting holes in the partially formed wheel disc.
[0013] [0013]FIG. 8 is a cross sectional view showing the final stamping of the partially formed wheel disc to produce a finished prior art full face fabricated wheel disc.
[0014] [0014]FIG. 9 is a sectional view of a prior art full face fabricated vehicle wheel.
[0015] [0015]FIG. 10 is a block diagram illustrating a sequence of steps for producing a full face fabricated vehicle wheel in accordance with the present invention.
[0016] [0016]FIG. 11 is a cross sectional view of a disc blank for use in producing the full face fabricated vehicle wheel in accordance with this invention.
[0017] [0017]FIG. 12 is a cross sectional view showing the stamping of the disc blank into a partially formed wheel disc in accordance with this invention.
[0018] [0018]FIG. 13 is a cross sectional view showing the forming of the windows in the partially formed wheel disc in accordance with this invention.
[0019] [0019]FIG. 14 is a cross sectional view showing the coining of the windows in accordance with the present invention.
[0020] [0020]FIG. 15 is a cross sectional view showing the trimming of the outer diameter and the forming of the center hub hole of the partially formed wheel disc in accordance with this invention.
[0021] [0021]FIG. 16 is a cross sectional view showing the forming of the flange outer and inner diameters, the forming of the lug bolt mounting holes, and the forming of the fit up area to produce a finished full face fabricated wheel disc in accordance with this invention.
[0022] [0022]FIG. 17 is a sectional view of a full face fabricated vehicle wheel in produced in accordance with this invention.
[0023] [0023]FIG. 18 is a sectional view showing the tooling for performing the stamping of the disc blank into the partially formed wheel disc illustrated in FIG. 12 in accordance with the present invention.
[0024] [0024]FIG. 19 is a sectional view similar to FIG. 12 showing the partially formed wheel disc after the stamping operation in accordance with the present invention.
[0025] [0025]FIG. 20 is a view of the outwardly facing surface of the vehicle wheel produced in accordance with the sequence of steps of the present invention.
[0026] [0026]FIG. 21 is a sectional view taken along line 21 - 21 of FIG. 20.
[0027] [0027]FIG. 22 is a sectional view taken along line 22 - 22 of FIG. 20.
[0028] [0028]FIG. 23 is a view of the outwardly facing surface of the prior art vehicle wheel produced in accordance with the prior art sequence of steps.
[0029] [0029]FIG. 24 is a sectional view taken along line 24 - 24 of FIG. 23.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Referring now to the drawings, FIG. 1 illustrates a block diagram showing a prior art sequence of steps for producing a full face fabricated steel vehicle wheel, indicated generally at 60 in FIG. 9. Initially, in step 10 , a flat sheet of steel material (not shown) is formed into a disc blank 30 , shown in FIG. 2. The disc blank defines a generally uniform disc thickness T. Following this, the disc blank 30 is initially stamped in step 12 to produce a generally bowl shaped disc 32 , shown in FIG. 3. The bowl-shaped disc 32 includes an outer annular portion 34 , an inner annular wheel mounting portion 36 having a “flattened” bottom, and an intermediate portion 37 having a generally concave profile. In particular, during the initial stamping operation of step 12 , the disc blank 30 is stamped to define a first predetermined axial distance A 1 defined between an inner surface 34 A of the outer annular portion 34 and an inner surface 36 A of the inner mounting portion 36 . Alternatively, in step 12 , the disc blank 30 can be stamped to produce an intermediate portion 37 having a generally straight profile (not shown).
[0031] The bowl-shaped disc 32 is then stamped into a partially formed disc 38 having a predetermined profile, shown in FIG. 4, during step 14 . Next, during step 16 , a plurality of windows 40 (only one window illustrated in FIG. 5) are formed in the disc 38 to produce a partially formed disc 42 . Following this, the windows 40 are coined and an outer edge of the partially formed disc 42 is trimmed to a predetermined diameter during step 18 to produce a partially formed disc 44 shown in FIG. 6. Next, in step 20 , a center hub hole 46 and a plurality of lug bolt mounting holes 48 (only one hole 48 is illustrated) are formed in the disc 44 to produce a partially formed disc 50 shown in FIG. 7. Following this, the partially formed disc 50 is restriked and then subjected to a final stamping operation during step 22 to produce a finished full face steel wheel disc 52 shown in FIG. 8. During step 22 , a second predetermined axial distance A 2 is defined between an inner surface 54 A of an outer annular portion 54 of the disc 50 and an inner surface 56 A of an inner mounting portion 56 of the disc 52 . In the illustrated embodiment, the second predetermined axial distance A 2 is less than the first predetermined axial distance A 1 . Alternatively, the second predetermined axial distance A 2 can be equal to the first predetermined axial distance A 1 . Following this, the full face disc 52 is secured to a partial steel wheel rim 59 during step 24 to produce the finished full face fabricated steel vehicle wheel 60 shown in FIG. 9.
[0032] Thus, in a conventional prior art full face steel wheel disc application, the initial stamping operation of step 12 is operative to form a bowl-shaped disc 32 having a finished part “tread” depth (i.e., the axial distances A 1 and A 2 are the same) or to form a bowl-shaped disc 32 having a deeper tread depth (i.e., the second axial distance A 2 is greater than the first axial distance A 1 ). Also, in a conventional prior art steel full face wheel disc application the initial stamping operation of step 12 is operative to form a bowl-shaped disc 32 wherein the intermediate portion 37 has a generally concave bowl wall surface (as shown in FIG. 3), or alternatively, a generally straight bowl wall surface (not shown). A generally similar sequence of steps can be used to produce a prior art full face fabricated aluminum vehicle wheel (not shown) having a prior art full face fabricated aluminum wheel disc (not shown).
[0033] Referring now to FIG. 10, there is illustrated a block diagram showing a sequence of steps for producing a full face fabricated vehicle wheel in accordance with the present invention. The full face fabricated vehicle wheel produced according to this sequence of steps is illustrated as being a full face fabricated steel or aluminum vehicle wheel, indicated generally at 78 in FIG. 17. However, it will be appreciated that the present invention can be used in conjunction with other types of fabricated steel or aluminum vehicle wheels having a full face fabricated steel or aluminum wheel disc. For example, the vehicle wheel can be a “modular wheel” construction including a “partial” rim and a full face wheel disc (such as shown in U.S. Pat. No. 5,360,261 to Archibald et al.), the disclosure of this patent incorporated herein by reference.
[0034] Turning to FIG. 10, a preferred sequence of steps for producing the full face fabricated vehicle wheel 78 of the present invention will be discussed. Initially, in step 100 , a flat sheet of suitable metal material (not shown) is formed into a disc blank 130 , shown in FIG. 11, by a metal forming operation. Preferably, the disc blank is formed by a stamping or blanking operation during step 100 . The disc blank 130 defines a generally uniform disc thickness T 1 .
[0035] Following this, the disc blank 130 is subjected to a metal forming operation in step 102 to produce a partially formed wheel disc 132 , shown in FIGS. 12, 18 and 19 , having fully formed stamped pockets. As shown therein, the partially formed wheel disc 132 includes an outer annular portion 134 , an inner annular wheel mounting portion 136 having a generally flattened bottom, and an intermediate portion 138 having finish formed pockets which are later subjected to a metal forming operation which is effective to produce a plurality of decorative windows in the wheel disc as will be discussed below. In particular, the metal forming operation of step 102 is a stamping operation whereby the disc blank 130 is engaged by a plurality of dies (seven of such dies 180 , 182 , 184 , 186 , 188 , 190 and 192 being illustrated in FIG. 18), and a binder ring or draw pad 194 .
[0036] During step 102 , the dies 180 - 192 are preferably operative to produce a partially formed wheel disc 132 having a first predetermined axial distance B 1 defined between an inner surface 134 A of the outer annular portion 134 and an inner surface 136 A of the inner annular portion 136 . As will be discussed below, by forming the partially formed disc 132 with the fully formed stamped pockets 138 directly from the flat blank 130 during step 102 , the initial stamping operation 12 associated with the forming of the prior art bowl-shaped disc 32 is eliminated and the use of the binder ring 194 during step 102 is effective to produce a wheel disc 132 without any of the “tooling marks” on the outboard face of the disc 132 which are present on an outboard face of the associated prior art wheel disc 52 . The term tooling marks as used herein refers to the visible marks on the outwardly facing surface of the full face wheel disc. This is shown by comparing the tooling marks, schematically indicated by dashed lines 52 A on the outwardly facing surface of the prior art wheel disc 52 of the prior art vehicle wheel 60 shown in prior art FIG. 23 and produced according the sequence of steps disclosed in prior art FIG. 1, to the “clean” (i.e., no visible tooling marks or virtually non-existent tooling marks) on the outwardly facing surface of the wheel disc 160 of the vehicle wheel 78 produced in accordance with the sequence of steps disclosed in FIG. 10 of the present invention. It is noted that lines 52 B shown on prior art FIG. 23 are shading lines for illustration purposes and are not tooling marks. Similarly, the lines 160 A shown on FIG. 20 are shading lines for illustration purposes.
[0037] The binder ring 194 is needed for two purposes. First, due to the rather extreme depth of the pockets 138 (and the resulting windows 142 discussed below), the depth being illustrated in FIG. 19 by reference letter D, the binder ring 194 is effective to eliminate undulation or rippling of the material on the periphery of the disc 134 which is produced during step 102 . The depth D being greater than around one-half inch and more preferably, the depth D being around one inch. In the prior art wheel, the depth of the windows is generally less than one-half inch. Secondly, the binder ring 194 allowed the flat disc blank 130 to be directly processed by only using a single stamping operation in step 102 to produce a partially formed/fully stamped wheel disc 132 .
[0038] Next, during step 104 , a plurality of decorative windows or openings 142 (only one of such windows 142 is illustrated in FIG. 13) are formed in the wheel disc 132 to produce a wheel disc 144 . In step 106 , the back side of the windows 142 are coined to produce a wheel disc 146 . Following this, an outer edge of the wheel disc 146 is trimmed to a predetermined diameter and a center hub hole 154 is formed in the disc 146 to produce a disc 148 during step 108 .
[0039] In step 110 , the disc 148 is restriked, the disc 148 is subjected to a final stamping operation to form a flange 162 , and a plurality of lug bolt mounting holes 156 (only one hole 156 is illustrated in FIGS. 16 and 17) are formed in the disc 148 to produce a finished full face steel wheel disc 160 shown in FIGS. 16 and 17. The flange 162 of the disc 160 is operative to define an outboard tire bead seat retaining flange of the vehicle wheel 178 . During step 110 , a second predetermined axial distance B 2 defined between an inner surface 162 A of the flange 162 and the inner surface 136 A of the inner annular portion 136 . Preferably, the second axial distance B 1 and the first axial distance B 2 are approximately the same. Alternatively, the second axial distance B 2 can be different from the first axial distance B 1 if so desired.
[0040] Following this, the full face wheel disc 160 is secured to a partial wheel rim, indicated generally at 170 in FIG. 17, by suitable means, such as for example by a weld 180 , to produce the finished full face fabricated steel vehicle wheel 78 shown in FIG. 17 of the present invention. The wheel rim 170 is preferably formed from the same material as the wheel disc 160 , and includes an inboard tire bead seat retaining flange 172 , an inboard tire bead seat 174 , a well, 176 , and an outboard tire bead seat 178 . Alternatively, the wheel disc 160 and/or the wheel rim 170 can be formed from different and/or other materials if so desired.
[0041] One advantage of the present invention is that the partially formed/fully stamped wheel disc 132 is formed directly from the disc blank 130 . As discussed above, the prior art method included the initial stamping operation of step 12 of the disc blank 30 into a generally bowl-shaped disc 32 . Thus, the present invention eliminates a metal forming operation that was necessary in the prior art method. Also, the present invention produces a wheel disc 160 having none or virtually no tool marks on the outwardly facing surface thereof thereby producing a more cosmetically appealing vehicle wheel outwardly facing surface. The prior art wheel disc 52 included tool marks on the outwardly facing surface thereof of the wheel disc 52 .
[0042] In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been described and illustrated in its preferred embodiment. However, it must be understood that the invention may be practiced otherwise than as specifically explained and illustrated without departing from the scope or spirit of the attached claims.
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This invention relates to an improved method for forming a full face fabricated vehicle wheel and includes the steps of: (a) providing a disc blank formed from a metal material; (b) subjecting the disc blank to a metal stamping operation to produce a partially formed non-bowl shaped full face wheel disc having at least one stamped pocket formed therein; (c) forming at least one decorative window in the partially formed full face wheel disc; (d) coining a back side of the window in the partially formed full face wheel disc; (e) trimming an outer edge of the partially formed full face wheel disc to a predetermined diameter; (f) forming a center hub hole in the partially formed full face wheel disc; (g) subjecting the partially formed full face wheel disc to one or more final metal forming operations to form at least one of an outer flange and a plurality of lug bolt mounting holes in the partially formed wheel disc so as to produce a finished full face wheel disc; and (h) securing the full face wheel disc to a preformed wheel rim to produce the finished full face fabricated vehicle wheel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of U.S. patent application Ser. No. 13/539,197, entitled “METHOD FOR A SECURE DETACH PROCEDURE IN A RADIO TELECOMMUNICATION NETWORK,” filed Jun. 29, 2012, which is a continuation of U.S. patent application Ser. No. 12/874,870, now U.S. Pat. No. 8,238,910, entitled “METHOD FOR A SECURE DETACH PROCEDURE IN A RADIO TELECOMMUNICATION NETWORK,” filed on Sep. 2, 2010, which is a continuation of U.S. patent application Ser. No. 11/449,025, now U.S. Pat. No. 7,809,372, filed Jun. 8, 2006, which is a continuation of U.S. patent application Ser. No. 09/627,684, now U.S. Pat. No. 7,085,567 filed on Jul. 28, 2000, which is a continuation of International Application PCT/EP98/08064, filed on Dec. 10, 1998. The subject matter of all of these applications is herby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to a method for performing a secure detach procedure in a radio telecommunication network, in particular in a so-called third generation network. Moreover, the present invention relates to a corresponding registration procedure for registering a subscriber to such a telecommunication network. Also, the present invention relates to corresponding devices of subscriber terminals and network controlling devices which are adapted to carry out these methods, and to a correspondingly adapted telecommunication network.
BACKGROUND OF THE INVENTION
In hitherto known telecommunication networks, a subscriber terminal as a first type radio transceiver device (hereinafter: mobile station MS), in order to be operated within a network, needs to be registered to the network NW, i.e. to a network controlling device like for example a mobile services switching center MSC (or an SGSN), which controls so called base station controllers BSC, which in turn control base stations BS as second type radio transceiver devices.
To this end, each subscriber has a subscriber identity module SIM to be inserted into the used mobile station MS as a respective terminal equipment. The SIM contains a pre-stored international mobile subscriber identity number IMSI, by which a user can be identified. However, in order to protect the user against being identified by an intruder in the network, each user is assigned a temporary mobile subscriber identity TMSI. This identification which changes either from time to time or from area to area (when combined with a location area identifier LAI) allows an “anonymous” identification of the user when using his terminal.
For details of the roughly described registration procedure including ciphering of transmitted data for authentication at registration, which details are considered to be not necessarily to be described here, the reader is referred to the plurality of respective publicly available GSM specifications.
Likewise, an attached or registered subscriber or mobile station, respectively, will have to perform a detach from the network under specific conditions. For example, the mobile station will be detached from the network and its registration will be abandoned, in case the SIM module is detached from the terminal equipment or the like.
In such cases, the mobile station MS sends a detach message to the network NW, the so-called IMSI DETACH INDICATION message. Upon receipt of the IMSI DETACH INDICATION the network controlling device (MSC) sets an inactive indication for the mobile station MS, while no response is returned to the mobile station itself. (For details, also in this context it is referred to the respective GSM specifications). Namely, no authentication is conducted at detach, when the mobile station initiating the detach procedure leaves the network.
Thus, there exists a possibility that a malicious user may obstruct or even terminate a third party's call by sending detach messages with random identities of mobile stations (i.e. random numbers of TMSI identifiers). Stated in other words, although it is not possible to interrupt the connection to a specific mobile station MS of a certain specified user by sending such a detach message, a lot of damage and irritation can be caused to a great number of users as well as to the operator of the network NW, when arbitrary calls and/or radio connections are blocked and/or terminated by the intention of a malicious third party.
A previously proposed approach to prevent this resides in performing an authentication procedure when a mobile station MS is to be detached from the network NW, i.e. upon receipt of a detach message at the network from the mobile station.
However, such a proposed authentication at detach is rather time consuming in many situations and has therefore only a limited applicability.
Moreover, performing an authentication procedure may not be feasible if the mobile station is performing power off, i.e. is switched off, or the available battery power is too low so that normal operation of the mobile station can not be assured any longer.
SUMMARY OF THE INVENTION
Hence, it is an object of the present invention to provide a simple and useful method for performing a detach from and/or a corresponding method for registration to a network, which prevent the above described problems.
According to the present invention, this object is achieved by a method for performing a detach of a terminal registered to a telecommunication network by associating an identification for said terminal, deriving a signature for said identification, and allocating a pair consisting of said identification and said signature to said terminal, said method comprising the steps of: sending a detach request including said identification and said identification signature from said registered terminal to said network; receiving said detach request at the network side; comparing said received detach request with a record of registration data of said terminal kept at the network side; and detaching said terminal from said network, if said received detach request coincides with said record of registration data.
According to the present invention, this object is furthermore achieved by a method for registration of a terminal to a telecommunication network, said method comprising the steps of: associating an identification for said terminal, deriving a signature for said identification, and allocating a pair consisting of said identification and said signature to said terminal.
Favorable refinements of the present invention are as defined in the respective dependent claims.
Thus, the present invention provides the advantage that a simple and useful method is available for preventing a malicious user to interrupt third party's calls by sending detach messages with random identities of mobile stations.
In particular, the proposed method enables an immediate authentication of the mobile station requesting a detach procedure upon receipt of the detach request message or the detach request, respectively. This authentication procedure is not time consuming and also applicable in case of a mobile station being switched off (entering the power off state) or having a battery level which is too low for normal operation of the mobile station. Thus, even in such situations, the detach procedure may be carried out correctly.
Moreover, due to the fact that the detach request is composed of the identifier as well as the identifier signature, the proposed immediate authentication process is highly secure, because in practice it is impossible to find such a matching pair by just taking two arbitrary numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more readily understood with reference to the accompanying drawings, in which:
FIG. 1 shows a flowchart of the registration procedure according to the present invention;
FIG. 2 shows a flowchart of the detach procedure according to the present invention; and
FIG. 3 shows a schematic representation of the data format used for the detach request or detach request message, respectively, according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to the present invention, when a mobile station MS as a first type radio transceiver station or, in general, a terminal is registered to a network NW like for example a so-called third generation radio telecommunication network, i.e. registered to the network controlling device MSC, it sends an attach/registration request (formed by one or more request messages), or dependent on the specific situation, a location update request to the network NW. A request as such (to be valid for being evaluated) may be composed of more than one transmitted messages.
The network NW, which for the present description is assumed to be represented by the network controlling device as for example an MSC, in turn associates an identification to the mobile station MS. Associating such an identification may be achieved in that the network NW allocates an identification to the terminal MS
The identification may be represented by the temporary mobile subscriber identity TMSI. Alternatively, as the identification also the international mobile subscriber identity IMSI could be used. In general, any suitable identification may be used for identifying a respective mobile terminal MS, and the present invention is not restricted to the use of the TMSI or the IMSI as identifications.
Additionally, the network NW allocates a signature (e.g. TMSI signature TMSI_SIG) corresponding to the identification and derived therefor on the basis of, for example, a coding algorithm like an algorithm known as the “Pretty Good Privacy” (PGP) algorithm, to the terminal, i.e. the mobile station MS. However, the deriving of the signature for and/or of the identification is not limited to the network side. Namely, alternatively, also the terminal MS may derive a signature for the identification by way of calculation. In this connection, information as to which algorithm for calculating the signature is to be chosen is in such a case exchanged between the network NW and the terminal MS. After having thus derived the signature, the deriving side (i.e. NW or MS) informs the other side of the derived signature.
Both data items, the identification TMSI as well as the identification signature TMSI_SIG are allocated to the mobile station MS in a secure mode, so that it is impossible for any other mobile station or any other third party to know the pair of these data items TMSI, TMSI_SIG. Of course, if in the above mentioned example case the terminal MS derives the signature, the derived signature is informed to the network NW in a secure mode, to be securely associated to the identification, so that it is impossible for any other mobile station or any other third party to know the pair of these data items TMSI, TMSI_SIG.
In particular, according to the present invention, the network NW or the network controlling device MSC, respectively, associates and/or allocates also a signature TMSI_SIG in combination with the identifier TMSI itself to the mobile station MS. Moreover, according to the present invention, the associated signature is used together with the identifier in a detach procedure, as described below.
Namely, in case the mobile station MS leaves the network NW and is to be detached therefrom due to, e.g., switching off the mobile station MS or a low battery charging state at the mobile station's side or a removal and/or taking off a SIM card (subscriber identity module) as examples for a respective predetermined detach condition for the mobile station, a detach procedure according to the present invention is performed. In particular, in this detach procedure, the mobile station MS when requesting and/or initiating detach, sends a detach request to the network NW. The detach request contains the identification TMSI and the identification signature TMSI_SIG as a pair of data items. The network compares the received two data items which identify the requesting mobile station with the previously allocated one's. If the comparison yields that the received data items are identical to the previously allocated one's, the detach is performed correctly at the network side. Because no other mobile station MS except the one to which the identifier signature and corresponding identifier were previously allocated to, knows the pair of data items, it is impossible for other mobile stations to perform a malicious detach procedure.
The following description of the drawings will set out the operation of the present invention in greater detail.
FIG. 1 shows a flowchart of the registration procedure. In step S 0 the registration procedure starts. In the subsequent step S 1 , it is checked at the mobile station MS side, whether a registration condition is present. Such a registration condition may for example be present when said mobile station newly attaches to a network NW and has initially to be registered (authenticated) at the network NW side, or when said mobile station has moved within the network NW and a location update of said mobile station MS becomes necessary. Alternatively, also a cell update in case of the terminal having moved to an extent that the previous cell has been left and a new cell was entered represents such a registration condition. Also, in third generation networks an URA (UTRAN Registration Area, UTRAN standing for “Universal Terrestrial Radio Access Network”) update is possible, thus representing a registration condition in the sense of the present invention. Such an URA update may be necessary in case of third generation networks, in which a radio network controller RNC handles the location information in terms of registration areas. Such updates become for example necessary when the mobile station has to be registered to another controlling device MSC within the network due to “excessive” moving within the network and/or in case of a request of the mobile station MS for a traffic channel assignment.
If no registration condition is present in step S 1 , the procedure returns to step S 1 until a registration condition is present. Then, the process proceeds to step S 2 .
In step S 2 , the mobile station MS sends a registration request REG_REQ to the network NW, i.e. to the network controlling device, e.g. the MSC. The registration request REG_REQ is for example an attach request for initial registration of said mobile station MS as a first type radio transceiver device in said network, or a location update request for updating a previous registration of said mobile station MS in said network, or any other request which is transmitted when any of the above described further possible registration conditions is satisfied.
In step S 3 , this registration request REG_REQ is received by the network controlling device. In response to receiving said request, the network controlling device selects or determines an identification like for example TMSI for the requesting mobile station MS.
Moreover, in a subsequent step S 4 of the described example, the network NW (network controlling device MSC) also derives an identification signature TMSI_SIG for said identification TMSI. (However, as mentioned above, the signature may also be derived by the mobile station MS itself upon receipt of a corresponding instruction from the network NW, and the signature will then have to be informed to the network NW (not represented in the figures).)
Both of these data items as parameters for identifying a specific mobile station MS, namely, the identification TMSI and the (separate) identification signature TMSI_SIG are allocated to the mobile station MS in a subsequent step S 5 . Of course, the network NW keeps a record of the thus assigned pair of data items.
The data items TMSI and TMSI_SIG are allocated in a secure mode, so that a third party may not obtain a knowledge of the assigned data items. Then, in step S 6 of the described example, they are transmitted from the network NW side to the mobile station MS side in order to inform the mobile station of the allocated identification TMSI and the identification signature TMSI_SIG.
Thereafter, in step S 7 , the registration procedure is completed.
FIG. 2 illustrates a flowchart of the detach procedure when a mobile station MS as a terminal is to be detached from the network it has previously been registered to.
The detach procedure starts in a step S 8 . In a subsequent step S 9 , at a respective mobile station MS side, it is checked whether a predetermined condition, i.e. a detach condition, of the mobile station MS is present. Such a detach condition may for example be met in case of a power off state of said mobile station MS, or in case a low battery charging state of the battery of the mobile station is detected. Alternatively, a user actuated command may fulfill the detach condition, for example, if another user wishes to use the mobile station MS as a terminal equipment and an SIM module (subscriber identity module) of the new user has to be inserted. This applies also in case of removal of the SIM module.
If no such detach condition as a predetermined condition is detected, the procedure loops until a corresponding condition is detected. If a detach condition is detected at the mobile station side, the mobile station MS sends a detach request DET_REQ to the network NW, i.e. to the network controlling device like an MSC, step S 10 .
The detach request DET_REQ contains said pair of said identification TMSI and said identification signature TMSI_SIG previously allocated to said mobile station MS upon registration of the mobile station to the network NW.
In particular, the detach request DET_REQ, may for example, assume a data format as shown in FIG. 3 of the drawings. As roughly schematically illustrated therein, a burst transmitted from the mobile station MS to the network NW (controlling device) contains the detach request DET_REQ. The detach request contains the pair of the identification TMSI and the identification signature TMSI_SIG. Although the TMSI and TMSI_SIG are illustrated as being transmitted immediately one after the other in the burst, another burst format may be adopted in that there may be provided a guard period or dummy period (not shown) between the respective data items. Alternatively, each data item could be identified by a respective flag (not shown) indicating which data item is transmitted next, and transmitted prior to the respective data item. Moreover, in the latter case, the order of the specific transmitted data items would not be restricted to a specific one, but could be changed in an arbitrary manner, as long as the data items could be identified at the reception side. Furthermore, the detach request could be transmitted in a form such that for example, the identification and the identification signature could be transmitted in consecutive bursts as respective request messages which in combination result in the request as such.
In step S 11 , the detach request DET_REQ is received at the network NW side. In a following step S 12 , the received detach request DET_REQ is compared, data item per data item, i.e. separately for the identification TMSI and the identification signature TMSI_SIG, with a record of registration data of said terminal kept at the network side. The record is the record of the previously assigned pair of data items TMSI, TMSI_SIG kept at the network NW side, as mentioned above in connection with step S 5 , upon registration of a respective mobile station MS to the network NW.
Namely, at the network controller side a set of such records (e.g. in form of a table) of all allocated pairs of data items TMSI, TMSI_SIG for all respective mobile stations currently registered to the network is kept, and in step S 12 a check is made as to whether the received pair of TMSI, TMSI_SIG is contained as a record in said set of records (table).
If the pair of data items received with the detach request message DET_REQ is not contained in said record (NO in step S 12 ), the procedure advances to step S 13 . In step S 13 , no detach operation is performed, and all registered mobile stations remain registered to the network. Also, an authentication procedure (registration) could then be started in this case in step S 13 . Therefore, a malicious user sending arbitrary identifications can not terminate any call or detach any other user, since he is not enabled to send a pair of matching data items of an identification TMSI and a corresponding identification signature TMSI_SIG.
If, however, the comparison in step S 12 yields that the received detach request DET_REQ contains a pair of data items TMSI, TMSI_SIG which is contained in the table of records, i.e. has previously been allocated to a mobile station upon registration, (YES in step S 12 ) then the flow proceeds to step S 14 .
In step S 14 , a detach operation is performed, since it has been verified that the detach request DET_REQ originated from an authentic mobile station which was previously registered to the network. Thus, an immediate authentication procedure can be carried out by comparing the pair of received data item TMSI, TMSI_SIG with a record of previously allocated (assigned) data items. This assures that a detach operation is only performed for a mobile station MS as a respective terminal, if the request for detach originates from the mobile station MS itself. Hence, no malicious user can initiate a detach of arbitrary mobile stations since he can not know the pair of the identification TMSI and the corresponding signature TMSI_SIG.
Moreover, the authentication at detach is immediately effected at the network side without involving a repeated handshaking procedure with the mobile station. Thus, the authentication procedure can also be successfully performed in case the mobile station has a too low battery charging level, has been switched off, or the like.
The procedure has been described herein above mainly with reference to the temporary mobile subscriber identity TMSI being used as an identification and for deriving the signature therefor, since the TMSI is already defined in existing radio telecommunication systems and, therefore, can be advantageously be used in connection with the present invention. Nevertheless, the present invention can also be carried out in case a new identification and corresponding signature thereof are defined, while this, however, would require additional changes to existing agreed standards.
It should be understood that the above description and accompanying drawings are only intending to illustrate the present invention by way of example. Thus, the preferred embodiment of the invention may vary within the scope of the attached claims.
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A method for performing a detach of a terminal registered to a telecommunication network is disclosed. The detach is performed by associating an identification for the terminal, deriving a signature for the identification, and allocating a pair consisting of the identification and the signature to the terminal. The method further includes sending the detach request including the identification and the identification signature from the registered terminal to the network. The detach request is received at the network and compared to a record of registration data of the terminal kept at the network. The terminal is detached from the network if the received detach request coincides with the record of registration data.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to bias circuits for switched capacitor circuits, and in particular, to bias circuits for switched capacitor circuits which compensate for process tolerances, temperature and clock frequency.
2. Description of the Related Art
In circuit applications involving switched capacitor circuits, the amplifiers are typically required to drive only capacitive loads which do not require much, if any, DC current. Accordingly, such amplifiers can be designed without a low impedance output stage, such as an emitter follower or source follower circuit. As a result of this design simplification, such amplifiers used in switched capacitor circuits typically have a high output impedance and are often referred to as “operational transconductance amplifiers” to differentiate them from operational amplifiers having low output impedance. Applications in which high output impedances are acceptable allow single-stage operational transconductance amplifiers to be used. Such amplifiers are typically folded-cascode or telescopic (i.e., unfolded cascode) designs.
Referring to FIG. 1, such an amplifier will typically have a single dominant pole, thereby making the unity gain bandwidth proportional to the ratio of the transconductance g m of the input stage and the load capacitance C LOAD . Accordingly, as represented in the graph of FIG. 1, this relationship between unity gain bandwidth frequency f unity , transconductance g m and load capacitance C LOAD can be expressed by Equation (1) below. f unity ∝ g m C LOAD ( 1 )
If the input differential pair of transistors (metal oxide semiconductor field effect transistors, or MOSFETs) of the operational transconductance amplifier are biased in the subthreshold region, then the input stage transconductance g m is inversely proportional to the product of Boltzmann's constant k and absolute temperature T divided by charge q. Accordingly, it follows that the input stage transconductance g m , using equations 2, 3 and 4 below, can be found using the drain current I D , majority carrier mobility μ, gate oxide capacitance per unit area C ox , channel width W and length L, gate-to-source voltage V GS , threshold voltage V T0 , source voltage V S and number n of output devices. If I D β · ( kT q ) 2 where β = μ C ox W L ( 2 ) Then I D = β ( kT q ) 2 ( ( V GS - V T0 - nV s ) nkT q ) ( 3 ) g m = ∂ I D ∂ V GS = I D nkT q ( subthreshold ) ( 4 )
Equations (1) and (4) can be combined to express the unity gain bandwidth frequency f unity according to Equation (5). f unity ∝ I D nkT q · C LOAD ( 5 )
As seen in Equation (5), if the drain current I D can be made proportional to the product of absolute temperature T and load capacitance C LOAD , the unity gain frequency f unity will be constant for all process and temperature variations. Ideally, the unity gain frequency f unity of the operational transconductance amplifier should track the frequency of the clock signal (with clock signal period T clock ) for the switched capacitor filter. Accordingly, relations for the unity gain frequency f unity and drain current I D can be expressed according to Equations (6) and (7) below. assuming f unity ∝ 1 T clock ( 6 ) then I D ∝ nkT q · C LOAD T clock ( 7 )
As should be recognized, the quotient of load capacitance C LOAD and clock signal T clock in Equation (7) is the approximate expression for a switched capacitor resistor equivalent.
Referring to FIG. 2, many conventional designs generate a PTAT (proportional to absolute temperature) bias current by developing a “difference voltage” across a resistor, where such “difference voltage” is the difference between the forward biased junction voltages of the diodes D 21 , D 22 . When the bias current lout generated by this circuit is substituted into Equation (4), the relationship for the subthreshold MOSFET transconductance g m can be expressed according to Equation (8) below. g m = I D nkT q = ln ( A ) n · R ( subthreshold ) ( 8 )
According to Equation (8), if the resistor R has no temperature dependance, the transconductance g m will be constant. Based upon this, it can then be shown that the unity gain frequency f unity of the operational transconductance amplifier can be expressed according to Equation (9). f unity ∝ ln ( A ) n · R ( 1 + aT + bT 2 ) · C LOAD ( 9 )
According to Equation (9), the unity gain frequency f unity and the settling of the operational transconductance amplifier is a function of the absolute tolerances of the resistor R (typically within a range of ±20%) and the load capacitance C LOAD (typically within a range of ±10%). Assuming a linear resistor temperature coefficient equal to +700 ppm/° C. and a temperature range of −40° C. to +85° C., the overall tolerance of the unity gain frequency will be within a range of ±40%. This implies that in order to guarantee that the operational transconductance amplifiers (which are biased by the circuit of FIG. 2) will meet minimum settling time requirements, the bias current must be 40% larger than what would otherwise be considered optimum.
Referring to FIG. 3, another conventional design provides a compensated reference current Iref which is a function of a reference voltage Vref, a capacitance C and clock signal period Td. (This circuit is described in more detail in E. A. Vittoz, “The Design of High-Performance Analog Circuits on Digital CMOS Chips,” IEEE Journal of Solid-State Circuits, Vol. SC-20, no. 3, June 1985, pp. 657-65.) This circuit forms a servo loop in which, during one clock phase Td, capacitor C is charged to the reference voltage Vref and transistor M 1 drains charge from capacitor Cs which is equal to the product of the reference current Iref and the clock period Td.
During the next clock phase, capacitors C and Cs are shorted together and also connected to the inverting input of the operational amplifier. If the charge drained from capacitor Cs by transistor M 1 was more than that which is now available via charge sharing from capacitor C (i.e., the product of the reference voltage Vref and capacitance C), then the inverting input of the operational amplifier will be pulled to a lower potential which, in turn, will cause the gate terminal of transistor M 4 to be pulled to a higher potential, thereby reducing the magnitude of the reference current Iref (due to the current mirror action of transistors M 3 and M 5 ).
This circuit has a number of disadvantages. This circuit requires a separate voltage reference circuit, the accuracy of the charge transfer (and power supply rejection) from capacitor C to capacitor Cs is sensitive to switch charge injection, and the value of the reference current is sensitive to the clock period Td. Additionally, this circuit is sensitive to parasitic capacitances on the top plates of capacitors C and Cs. Stray capacitances on these nodes will become discharged when the voltage changes during different clock cycles.
Referring to FIG. 4, another conventional design operates in an “open loop” manner and does not use any feedback. (This design is discussed in more detail in Olesin et al., U.S. Pat. No. 4,374,357, the disclosure of which is incorporated herein by reference.) In this design, capacitors C 22 and C 40 are alternately charged and discharged by transistors M 18 , M 20 , M 36 and M 38 during successive states of the clock signal. An average current equal to the product of the capacitance of capacitor C 22 (or capacitor C 40 since they are equal), the reference voltage Vref and two times the frequency of the clock signal (=C 22 *Vref*2*f clock ) flows through the diode-connected MOSFET M 50 . The gate terminal of transistor M 50 is a low impedance node which is bypassed by filter capacitor C 52 and is used to bias transistor M 54 .
This circuit also has a number of disadvantages, including poor accuracy and poor power supply rejection. There are inherent errors caused by the drain voltage of transistor M 50 not matching the drain voltage of transistor M 54 , as well as mismatched drain voltages for transistors M 56 and M 60 , transistors M 62 and M 64 , and transistors M 28 and M 30 . Additionally, this circuit provides little high frequency ripple filtering due to the lack of high impedance nodes. All filter capacitors are connected directly across diode-connected transistors (e.g., transistors M 50 and M 56 ). Accordingly, the reference current generated by this circuit will have ripple at twice the frequency of the clock signal.
SUMMARY OF THE INVENTION
A switched capacitor bias circuit for generating a reference signal which is proportional to absolute temperature, capacitance and clock frequency in accordance with the present invention uses a double-sampled switched capacitor “resistor” and an integration capacitor within a PTAT (proportional to absolute temperature) loop to generate bias currents which are proportional to capacitance, clock frequency and absolute temperature. Such currents are optimal for biasing operational amplifiers in switched capacitor filters where settling is dominated by the closed loop bandwidth rather than slewing. Such a circuit compensates for variation in the load capacitance and temperature to minimize power dissipation.
In accordance with one embodiment of the present invention, an integrated switched capacitor bias circuit for generating a reference signal which is proportional to absolute temperature, a capacitance and a clock signal frequency includes a current mirror circuit, a bias circuit and a switched capacitor circuit. The current mirror circuit is configured to receive a bias voltage and in accordance therewith provide a primary current, first and second mirrored currents and a node voltage, with the node voltage being responsive to the first mirrored current. The bias circuit, coupled to the current mirror circuit, is configured to receive the node voltage and in accordance therewith provide the bias voltage. The switched capacitor circuit, coupled to the current mirror circuit, includes a capacitance and is configured to receive first and second clock signals which are equal in frequency and mutually inverse in phase and in accordance therewith receive and conduct the first mirrored current in proportion to an absolute temperature of the switched capacitor circuit, the capacitance and the clock signal frequency. The second mirrored current is proportional to a product of the absolute temperature, the capacitance and the clock signal frequency.
In accordance with another embodiment of the present invention, a method of generating a reference signal which is proportional to absolute temperature, a capacitance and a clock signal frequency includes the steps of:
receiving a bias voltage and in accordance therewith generating a primary current, first and second mirrored currents and a node voltage, wherein the node voltage is responsive to the first mirrored current;
receiving the node voltage and in accordance therewith generating the bias voltage; and
receiving, with a capacitive circuit having a capacitance, first and second clock signals which are equal in frequency and mutually inverse in phase and in accordance therewith receiving and conducting the first mirrored current in proportion to an absolute temperature, the capacitance and the clock signal frequency;
wherein the second mirrored current is proportional to a product of the absolute temperature, the capacitance and the clock signal frequency.
These and other features and advantages of the present invention will be understood upon consideration of the following detailed description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram and corresponding frequency response graph for the open loop frequency response of a typical operational transconductance amplifier.
FIG. 2 is a schematic diagram of a conventional PTAT current generator.
FIG. 3 is a schematic diagram of a conventional voltage-to-current conversion circuit.
FIG. 4 is a schematic diagram of a conventional switched capacitor reference current source.
FIG. 5 is a schematic diagram of a switched capacitor bias circuit in accordance with one embodiment of the present invention.
FIG. 6 is a timing diagram with waveforms for selected signals in the circuit of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 5, a switched capacitor bias circuit (preferably in integrated circuit form) for generating a reference signal which is proportional to absolute temperature, a capacitance and a clock signal frequency in accordance with one embodiment of the present invention uses a double-sampled switched capacitor “resistor” Cs and an integration capacitor CI inside a PTAT loop to generate an output bias current Ibias which is proportional to the clock frequency and absolute temperature, as well as its load capacitance. Transistors M 1 , M 2 , M 4 and M 5 form part of a current mirror circuit which is biased by a bias circuit formed in part by transistors M 3 and M 6 . Capacitors CI and Cs and transistors Msa, Msb, Msc and Msd form a switched capacitor circuit which uses a mirrored current I 1 from the current mirror circuit to accumulate and discharge charges across the capacitors CI, Cs (as discussed in more detail below). Diode D 2 has a junction area of A and can be implemented as a parasitic substrate PNP transistor. Diodes D 1 and D 3 have normalized junction areas of unity.
An additional current mirror branch circuit is formed in part by transistors M 7 and M 8 to produce the output bias current I bias which is a replicated, i.e., mirrored, version of the primary current mirror current I 2 . The master clock signal CLOCK is inverted by an invertor circuit to produce corresponding inverse clock signals CLOCK, {overscore (CLOCK)} for driving the switching transistors Msa, Msb, Msc, Msd within the switched capacitor circuit.
The PTAT loop servos in such a manner as to maintain the voltage VI across the integrating capacitor CI at a value which is equal to an average of the natural logarithm of the area A of diode D 2 times Boltzmann's constant K times absolute temperature T divided by charge q (=In(A)*KT/q). If the voltage VI across the integration capacitor CI becomes less than this average, this means that diode D 2 is conducting more current than D 1 . Under these conditions, current I 1 through transistor M 1 is greater than the primary current mirror current I 2 . Due to the current mirror action of transistors M 4 and M 5 , the drain current of M 4 is equal to the primary mirror current I 2 . However, since the drain current of transistor M 1 is greater than the primary mirror current I 2 , i.e., drawing more current from the node connecting the gate terminal of transistor M 6 and compensation capacitor Cc, the voltage at node A decreases. In turn, this causes the drain current of transistor M 6 to increase, thereby causing the voltage at node C to increase. Further in turn, this pulls up the voltage potential at the gate terminal of transistor M 1 , thereby increasing the voltage potential at node B. Still further in turn, this causes the average of the voltage VI across the integration capacitor CI to increase. Hence, this feedback action drives the loop to correct and maintain the average value of the voltage VI across the integration capacitor CI.
In summary then, the average value of the voltage VI across the integration capacitor CI is a function of the area A of diode D 2 . Since diode D 2 has a larger junction area than diode D 1 , the current density in diode D 2 is less than the current density in diode D 1 and, therefore, the forward-bias voltage drop VD 2 across diode D 2 is less than the forward-bias voltage drop VD 1 across diode D 1 . Hence, since the voltages at the source terminals of transistors M 1 and M 2 are equal, this voltage difference VD 2 −VD 1 appears in the form of the voltage VI across the integration capacitor CI.
Referring to FIG. 6, the operation of this circuit can perhaps be better understood by considering the details of the voltage within the switched capacitor loop. During both phases CLOCK, {overscore (CLOCK)} of the clock signal, the drain current I 1 of transistor M 1 will charge a total capacitance of CI+Cs, thereby creating a ramp-shaped voltage waveform. For a 50% duty cycle clock signal the ramp will move linearly from a minimum voltage Vmin to a maximum voltage Vmax. Each time a sampling capacitor CS with zero initial voltage (due to the discharging action of transistors Msa and Msd) is switched across the integration capacitor CI, charge sharing occurs. This charge sharing action establishes the ratio of the minimum voltage Vmin (i.e, the initial ramp voltage) to the maximum voltage Vmax (i.e., the final ramp voltage) as the ratio of CI/(Cs+CI). Because the ramp is linear, the average voltage is equal to ln(A)KT/q, i.e., the arithmetic mean of the maximum Vmax and minimum Vmin voltages. This can be expressed according to Equation (10) below. V avg = ln ( A ) · KT q = 0.5 · V max · ( 1 + CI CI + Cs ) ( 10 )
Rearranging and solving for the maximum voltage Vmax produces Equation (11). V max = 2 · ln ( A ) · KT q · ( CI + Cs 2 · CI + Cs ) ( 11 )
The minimum voltage Vmin can then be found using Equations (12) and (13). V min = V max · ( CI CI + Cs ) ( 12 ) V min = 2 · ln ( A ) · KT q · ( CI 2 · CI + Cs ) ( 13 )
The amplitude of the voltage ramp is the difference between the maximum Vmax and Vmin voltages, as expressed in Equation (14). V max - V min = 2 · ln ( A ) · KT q · ( CI 2 · CI + Cs ) ( 14 )
To solve for the drain current I 1 of transistor M 1 , it is noted that the load capacitance during charging is the sum of the sampling capacitance Cs and integration capacitance CI. During steady state operation, the primary current I 2 and mirrored currents I 1 , Ibias are equal. Therefore, the output bias current Ibias can be computed in accordance with Equation (15). Ibias = ( Cs + CI ) · v T = 4 · ( Cs + CI ) · ln ( A ) · KT q · ( Cs 2 · CI + Cs ) T clock ( 15 )
Accordingly, by substituting Equation (15) into Equation (5) the relationship for the unity gain frequency f unity can be expressed according to Equation (16). f unity ∝ 4 · ( Cs + CI ) · ln ( A ) · ( Cs 2 · CI + Cs ) n · C LOAD · T clock ( 16 )
Under normal circumstances, the sampling capacitance Cs, integration capacitance CI and load capacitance C LOAD (not shown) will track each other due to the fact that the corresponding capacitors are fabricated from the same material. Accordingly, it can be seen in Equation (16) that the unity gain frequency f unity will be inversely proportional to the clock period, or alternatively, proportional to the clock frequency.
The circuit of FIG. 5 provides a high degree of power supply rejection since the drain and source voltages of all “matched” device pairs are designed to be matched within tens of millivolts. For example, transistor pair M 1 /M 2 and pair M 4 /M 5 have well matched operating points.
Further, charge injection is inherently cancelled by the double sampling design. For example, when switching transistor Msb turns off, thereby dumping its channel charge, transistor Msa turns on, thereby collecting the channel charge. Similar charge injection cancellation occurs on the opposite clock phase with transistors Msc and Msd.
Further still, node A is a high impedance node at which compensation provides a low frequency dominant pole that filters out ripple. The compensation capacitor Cc provides the low frequency filter pole at the frequency of 1/(Rds*Cc). Additional filtering and power supply rejection is established based upon the RC time constant of the filter capacitor Cfilter and the drain-to-source resistance of transistor M 7 which is biased in triode mode (resistive) with a bias voltage V 1 .
The foregoing equations assume that the operational transconductance amplifiers are biased in subthreshold mode. If, however, the input MOSFETs are biased in strong inversion modes, other equations will apply. For example, for biasing in saturation mode, Equation (17) below will apply. g m = ∂ I D ∂ V GS = 2 μ CoxWI D L ( saturation ) ( 17 )
Substituting for the drain current I D in Equation (15) into Equation (17), we obtain Equation (18). g m = 2 μ CoxW ( 4 · ( Cs + CI ) · Cs · ln ( A ) · KT ) L · q · ( 2 · CI + Cs ) · T clock ( 18 )
The carrier mobility μ has a temperature dependence of T −{fraction (3/2)} . When this is combined with the linear temperature dependence of the PTAT current, the overall temperature variance of the transconductance g m will be T −¼ . For a temperature range of −40 to +100° C., the overall spread of transconductance g m variations due to temperature will be within a range of ±5.7%.
The unity gain frequency f unity is proportional to the quotient of the transconductance g m and load capacitance C LOAD (=g m /C LOAD ). Substituting this expression into Equation (18) demonstrates that the sensitivity of the unity gain bandwidth f unity to capacitor variations is −½. In other words, for every 10% increase in capacitance value, the unity gain frequency will decrease by approximately 5%. Additionally, there will be a dependence upon the effective channel length L of the transistors.
Various other modifications and alterations in the structure and method of operation of this invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. 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. It is intended that the following claims define the scope of the present invention and that structures and methods within the scope of these claims and their equivalents be covered thereby.
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An integrated switched capacitor bias circuit for generating a reference signal which is proportional to absolute temperature, a capacitance and a clock signal frequency. A current mirror circuit generates a primary current and a mirrored current. Under the control of a clock signal, a switched capacitor circuit uses the mirrored current to constantly accumulate charges on primary capacitor while also alternately sharing such charges with and then discharging one of two additional capacitors. The magnitude of the current drawn by the switched capacitor circuit is a factor of the junction area of a diode and absolute temperature. To maintain equality of the primary and mirrored currents, a node voltage within the current mirror circuit is monitored by a bias circuit which provides a bias signal for controlling the current mirror circuit. An additional current replication stage is driven by the current mirror circuit to provide an additional mirrored current which is proportional to a product of absolute temperature and the frequency of the clock signal.
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FIELD OF THE INVENTION
The invention relates to a method and an apparatus for covering printed products with a packaging material.
BACKGROUND OF THE INVENTION
Individual printed products or a group of a number of printed products are packed for dispatch by being covered on all sides with a wrapper, paper or a film or inserted into envelopes. One method of packing printed products, in which the latter are inserted into packaging elements which are located in insertion compartments in a packing drum, is disclosed by U.S. Pat. No. 5,615,537. With this method, a high throughput of products to be packed is possible, and it necessitates prefabricated packing elements and is therefore correspondingly expensive.
German Patent No. DE-A 31 02 872 discloses a method of covering chocolate bars and the like, in which a continuous packaging material, a metal foil, is folded over to form a tube which is open on one side and has a U-shaped cross section. Bars lying one behind the other in a row are placed into said tube, the open side of the tube then being closed and individual pack units being divided off.
SUMMARY OF THE INVENTION
The invention is based on the object of specifying a method and an apparatus for packing printed products with which a high throughput can be achieved with the lowest possible material and processing costs per pack unit.
According to the invention, at least two printed products are packed in parallel with a common packaging material web. As a result, the tools which are present to feed products, to unwind and fold over the packaging material, especially a plastic film, and to close and, if necessary, divide off the pack units can advantageously be used twice over. The packing rate can be doubled at constant processing speed. According to the invention, the packaging material web is itself used as a transport medium after the printed products have been deposited on it. The material web preferably runs over a support which accommodates the weight of the printed products. It is particularly advantageous if the cross section of the support is bent over upward or downward at right angles to the conveying direction, and has contact elements for printed products, so that the latter assume a defined position with respect to the cutting and closing tools. The continuous packaging material used is preferably a plastic film, but a paper web can also be employed. A plastic film is preferably welded in order to produce the pack, while a paper web is adhesively bonded.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are illustrated in the drawing and described below. In the drawing, in purely schematic form:
FIG. 1 shows an apparatus for implementing the method;
FIGS. 2 a, b show an example of a method according to the invention, forming a U-shaped, laterally open material tube;
FIGS. 3 a, b show an example of a method according to the invention, forming a material tube closed at the top;
FIGS. 4 a, b show an example of a method according to the invention, forming a material tube open at the top;
FIGS. 5 a, b show a further example of a method according to the invention, forming a material tube open at the top;
FIGS. 6 a, b show an example of a method according to the invention, forming two pockets from a packaging material web;
FIGS. 7 a-d show an example of a method according to the invention, forming a loop of packaging material between the printed products;
FIGS. 8 a-c show a further example of a method according to the invention, forming a loop of packaging material between the printed products;
FIGS. 9 a, b show a third example of a method according to the invention, forming a loop of packaging material between the printed products;
FIGS. 10 a-c show three examples of the shape of a support for the packaging material.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows, schematically, an apparatus for implementing the method according to the invention. A similar apparatus for packing one product in each case is described in DE-A 31 02 872. In relation to the construction and functioning of the apparatus according to the invention, reference is also made to this disclosure.
Printed products 1 , 2 are fed to the apparatus in the conveying direction F in two parallel rows 26 , 27 by a feed device 25 . The feed device 25 has, for example, a conveyor belt 25 ′ with driving elements 34 , for example rollers, which are arranged at right angles to the conveying direction F and between which printed products lie. Instead of a belt conveyor, cam conveyors, gripper conveyors and clamp transporters and the like can also be used as the feed device. The printed products do not necessarily have to arrive in rows, but, for example, can also arrive in an overlapping formation or can be drawn off from a stationary stack. In this case, it is merely necessary for two printed products in each case to be deposited beside each other on the packaging material, that is to say the packaging material web 3 ′.
A packaging material web 3 ′, a plastic film here, is unwound over guide rollers 35 from a feed roll 28 oriented at right angles to the feed device 25 and to the conveying direction F. The packaging material web 3 ′ can also be supplied in any other way and laid around the products. The guide rollers 35 are arranged parallel to the feed roll 28 , approximately symmetrically with respect to the plane of the feed device 25 .
By means of a turner device 30 , which is formed here by pairs of rollers 31 , running at the side of the feed device 25 , and the guide rollers 35 , the initially flat packaging material web 3 ′ is used to form a material tube 3 ′ which has a U-shaped cross section, is open at the sides and has an upper and a lower material layer 8 and 9 , respectively. Said hose is laid around the printed products 1 , 2 supplied, the latter being deposited on the lower material layer 9 by the feed device 25 . The packaging material web 3 ′ itself is used as a transport medium for the printed products 1 , 2 after they have been deposited. It is moved in the conveying direction F by the pairs of rollers 31 .
Above the central area 4 between the printed product rows 26 , 27 and between the printed products 1 , 2 there is a first closing device 33 for joining the upper and lower material layers 8 , 9 . In the present case, the first closing device 33 comprises 2 wheels 33 ′, 33 ″ which can be rotated about a common axis and with which the layers 8 , 9 are joined to each other continuously, being welded here, so that two welds running in parallel in the conveying direction F are produced. In order then to divide the pack units of one row 26 from those of the other row 27 , a blade 36 oriented in the conveying direction F is arranged as a dividing device downstream of the first closing device 33 . Alternatively, a dividing device can also be integrated into the closing device 33 , for example a blade can be arranged between the wheels 33 ′, 33 ″ between the welds. In the area of the edge 10 , there is arranged a continuously operating second closing device 32 , which likewise welds the upper and lower material layers 8 , 9 in the edge area in the conveying direction F. Arranged downstream of the first closing device 33 , in the conveying direction F, is a third closing device 29 which, transversely with respect to the conveying direction F, joins the packaging material webs (welds them here) in the region between two successive printed products at regular time intervals matched to the conveying speed and the product spacing. Using a second dividing device with a blade 37 oriented transversely with respect to the conveying direction, a finished pack unit is then divided off. It is possible for the second dividing device to be dispensed with for those applications in which the printed products are to be stored temporarily individually packed in a continuous material web tube.
FIGS. 2 a ) and b ) show two steps in a variant of the method according to the invention, in schematic form. The method can be implemented with the apparatus shown in FIG. 1. A packaging material web 3 ′ in the form of a plastic film is used to form a material tube 3 ″ which has a U-shaped cross section, is open at the side and has an upper and a lower material layer 8 and 9 , respectively. Two printed products 1 , 2 , which arrive in parallel printed product rows, as shown in FIG. 1, are placed beside each other on the lower material layer 9 . In the central area 4 between the two printed products 1 , 2 , the lower and the upper material layers 8 and 9 are welded to each other, forming welds 5 , 6 running in the conveying direction F, the packaging material web 3 ′ being divided between them along a cutting line 7 likewise running in the conveying direction F. Alternatively, a wide weld can be formed, which is divided at its center, so that the upper and lower material layers in each case remain joined. To the side of one of the printed products 2 , an edge 10 comprising upper and lower material layers 8 , 9 projects, and is closed by a further weld 11 running in the conveying direction. In the area between printing products lying one behind the other, the packaging material web 3 ′ is finally welded and cut transversely with respect to the conveying direction F, in order to complete the packaging and to separate printed products which arrive one after the other from one another.
FIGS. 3 a ), b ) show two steps in a further variant of the method according to the invention, in schematic form. The printed products 1 , 2 are deposited beside each other on the packaging material web 3 ′, to be specific approximately at the center. In this case, first and second outer material areas 12 , 13 in each case project laterally outward, which is illustrated by dashed lines. The projecting first and second outer material areas 12 , 13 are then folded over toward the central area 4 to form a tube 3 ″ of packaging material. The folded-over first and second outer material areas 12 , 13 are sufficiently long that they overlap each other in an overlap area 14 . In this overlap area 14 between the printed products 1 , 2 arranged beside each other, they are welded to each other and to the material layer lying underneath in one operation. As in the method of FIG. 2, two parallel welds 5 , 6 can be applied, a cut being made between them, cutting line 7 . This variant has the advantage over the variant of FIG. 2 that, in addition to the necessary welding and dividing transversely with respect to the conveying direction, only one closing device operating in the conveying direction or only one operation is needed in order to form two packs.
FIGS. 4 a ), b ) show two steps in a further variant of the method according to the invention, in schematic form, similar to the method from FIGS. 3 a ), b ). The laterally projecting first and second outer material areas 12 , 13 are shown shorter here than in FIGS. 3 a ), b ), so that they do not overlap when folded over toward the central area 4 . They are then welded individually onto the lower material layer 9 , in each case with a weld 5 , 6 . The area between them is cut along the cutting line 7 .
In the variant of the method according to the invention shown in FIGS. 5 a ), b ), the printed products are again placed approximately centrally on the packaging material web 3 ′, and the projecting first and second outer material areas 12 , 13 are turned over toward the center. In the central area 4 , the packaging material web 3 ′ is cut along the cutting line 7 . The first and second inner material areas 15 , 16 formed as a result are turned over outward, so that they overlap the first and second outer material areas 12 , 13 . In the overlap area on the flat side of the products 1 , 2 , the first and second material areas 12 and 15 and 13 and 16 , respectively, are welded to each other (welds 5 , 6 ).
In the variant of the method according to the invention shown in FIGS. 6 a ), b ), the printed products 1 , 2 are inserted, standing upright, into two parallel loops 23 , 24 made of a single packaging material web 3 ′ having a U-shaped cross section in each case. The packaging material 3 is severed in the axial direction along a cutting line 7 in the center between the loops. The two material layers of a loop are in each case welded to each other, the welds 5 ′, 6 ′ in this case being applied in the horizontal direction.
FIGS. 7 a ) to d ) show, in schematic form, four steps in a further variant of the method according to the invention, in which the film-like packaging material 3 is drawn up or forced up in the central area 4 between the two deposited printed products 1 , 2 , forming a loop 22 , FIGS. 7 a ), b ). The loop 22 has a length L 1 and the laterally projecting outer material areas 12 , 13 have a length L 2 , the sum L of the lengths L 1 and L 2 being greater than the width B of the printed products 1 , 2 . In addition, L 1 >B here. The loop 22 is cut centrally at the highest point, cutting line 7 , so that loose inner material areas 15 , 16 are formed. These are turned over outward and in each case joined to the outer material areas 12 , 13 by welds 5 , 6 , FIGS. 7 c ), d ).
FIGS. 8 a ), b ), c ) and 9 a ), b ) show modifications of this method from FIGS. 7 a ), b ). In FIGS. 8 a ), b ), c ), the length L 1 of the loop 22 is less than the length L 2 of the outer material areas 12 and 13 , and L 1 <B. The outer material areas 12 and 13 are folded inward, and the inner material areas 15 and 16 are folded outward after the loop 22 has been divided. The material areas are joined to each other in the overlap area on the flat side of the products 1 , 2 . In FIGS. 9 a ), b ), the loop 22 has a length L 1 which is somewhat greater than half the width B of the printed product. Inner and outer material areas 12 , 13 , 15 , 16 are folded outward and inward, respectively. In the case of the method from FIGS. 8 and 9, welding can advantageously be dispensed with if the material areas overlap to a sufficient extent, since the covering is sufficiently stable because of the transverse welding (not shown).
Finally, FIGS. 10 a ) to c ) show three variants of supports 17 , 18 , 19 for the packaging material 3 and the printed products 1 , 2 . The film-like packaging material 3 , not illustrated in FIGS. 10 a ) and 10 b ), is in each case located between the support and the printed products 1 , 2 . A flat support 17 is shown in FIG. 10 a ). It preferably has an aperture (not illustrated) in the central area 4 , in order, in accordance with the method variant illustrated in FIGS. 7 to 9 , to be able to form a loop of film by means of pressure from below. The support 18 from FIG. 10 b ) is bent in a V shape in the cross section, so that the printed products 1 , 2 placed on the packaging material web (not illustrated here but lying on the support) slide toward the central area 4 because of the force of gravity. In order to produce a defined position of the printed products 1 , 2 in relation to each other and in space, the support 18 has contact elements 20 , for example webs, in the central area 4 , on which the printed products 1 , 2 rest. The support 19 from FIG. 10 c ) is likewise bent with a cross section in the shape of a saddle roof and a tip pointing upward. Printed products 1 , 2 placed onto the support 19 or onto the packaging material web 3 ′ lying thereon slide outward, on account of the force of gravity, and are retained by contact elements 21 , which are formed by a step in the support 19 .
While preferred embodiments of the invention have been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all methods and devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.
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The invention relates to a method and an apparatus for covering printed products with a packaging material in the form of a continuous packaging material web, especially a plastic film. In each case, at least two printed products are deposited beside each other on the packaging material web by means of a feed device. In each case, at least two printed products lying beside each other are covered simultaneously with the packaging material and subsequently divided from each other. The invention permits the packaging rate to be doubled in a simple way, without having to carry out complicated modifications to the packaging apparatus.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the sealing of a sodium-containing region in an electrochemical device, such as a cell utilising liquid sodium and solid electrolyte permeable to sodium ions. The invention has particular application to electrochemical cells, such as for example sodium sulphur cells, making use of sodium as one of the electrode materials.
2. Prior Art
A sodium sulphur cell contains liquid sodium separated by a sodium-ion permeable solid electrolyte, usually beta-alumina, from a cathodic reactant comprising liquid sulphur and sodium polysulphides. The sodium and the cathodic reactant are highly reactive materials and it is essential that the cell should be properly sealed to prevent any escape of these materials. Various types of seals have been proposed heretofore. Mechanical hermetic seals are disclosed for example in U.S. Pat. Nos. 3,946,751 and 3,959,013.
The present invention is concerned more particularly with glass seals. The use of glass seals is described, for example in U.S. Pat. Nos. 3,928,071, 3,826,685 and 3,868,273. It is convenient, in sodium sulphur cells and similar electrochemical cells to use a glass as a bonding agent between a ceramic material and a metal member. In a sodium sulphur cell, the closure may be effected by sealing the ceramic electrolyte material to a closure member or to the housing. It is well-known however to put an alpha-alumina extension onto a beta-alumina ceramic tube to have a non-conductive end portion of the tube. This may readily be done with a glass seal. The alpha-alumina extension then has to be sealed to the housing or to the closure member. The closure member may be a part of a current collector. Thus glass may be employed, in sealing a cell, as a bond between solid electrolyte material, e.g. beta-alumina ceramic, or an insulating ceramic, e.g. alpha-alumina, and a metal component or components such as a current collector, an intermediate component, or an external housing. The glass-to-metal bond is formed by a reaction between the glass and an oxide layer on the metal. The glass employed is a sodium-resistant glass, such as an aluminate or alumino-borate glass. The metal material has to be chosen in accordance with both mechanical and chemical requirements. In particular, it must resist attack by sodium at elevated temperatures. It is the practice in sodium sulphur cells to use mild steel or stainless steel for the housing, in contact with the sodium.
The glass-to-steel bond formed is an oxide bond and applicant has found that the oxide material of the bond is reduced leading to bond weakening and eventually seal failure, when this bond is exposed to sodium vapour. The problem arises very particularly at the elevated temperatures employed in electrochemical cells using liquid sodium which may typically operate at temperatures of 350° to 400° C. Although techniques have been devised for sealing metal direct to ceramic material so as to avoid the use of glass, there are substantial advantages in the employment of glass as a bonding agent in electrochemical cells of the kind described above. The present invention is directed to preventing or minimising glass-to-metal bond weakening in the presence of sodium vapour.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, in an electrochemical device having a sodium-containing region partially bounded by a sodium-ion permeable solid electrolyte element and having the sodium-containing region sealed by a sodium-resistant glass seal joining the ceramic electrolyte or a ceramic extension thereof to a metal member the surface of the metal member, at least in the region of the periphery of the glass-metal interface subjected to exposure of the sodium, is coated with a protective layer of niobium or a film of niobium is secured to the metal member in the region thereof exposed to the sodium, which film extends into said glass-metal interface. Niobium is a protective metal as its oxide is stable against reduction by sodium liquid or vapour. Applicant has found that niobium, arranged as described above, gives satisfactory protection to a glass-to-metal seal in a sodium sulphur cell. Niobium will give long-term protection, unlike titanium or zirconium which might be thought suitable but which give only limited protection. It will be seen that the protective metal coating or film gives protection to said metal member in the region where the metal-glass interface would, in the absence of the protective metal, be exposed to the sodium vapour. The presence of the protective metal, due to the stability of its oxide, gives a high degree of protection against weakening of the bond to the glass. The glass must be a sodium-resistant glass. In this way protection can be obtained for the glass-metal bond subjected to sodium vapour. This glass-to-metal seal may be employed in making a seal to a metal member of mild steel or stainless steel or corrosion-resistant nickel alloy such as nickel iron alloy.
In a sodium sulphur cell, the seal must be able to withstand temperature cycling and, using a seal as described above, the metal member should have a coefficient of thermal expansion similar to that of glass and the ceramic, e.g. beta-alumina or alpha-alumina. If the cell housing is made of a metal having a suitable coefficient of expansion, referred to hereinafter as a controlled expansion metal, then a niobium coating could be put on the appropriate part of the metal housing where the seal is to be formed. More generally, however, the cell housing has to be made of a metal such as mild steel or stainless steel which has a coefficient of expansion greater than that of the glass, alumina and niobium. In this case, it is preferred to use an intermediate metal member of a suitable coefficient of expansion, referred to hereinafter as a controlled expansion alloy. The material must be chemically compatible with the materials with which it is in contact; a number of nickel alloys, such as nickel-iron corrosion-resistant alloys, e.g. Nilo 42 or Nilo K, are suitable. Nilo 42 is a binary nickel-iron alloy containing about 42% by weight of nickel. Nilo K is a nickel-cobalt-iron alloy containing about 29.5% by weight of nickel and about 17% by weight of cobalt.
The invention furthermore includes within its scope a sodium sulphur cell having a solid sodium-ion permeable electrolyte separating a sodium compartment from a cathodic reactant compartment wherein the sodium compartment is at least partially bounded by a metal housing and is sealed by sealing means between the electrolyte and the housing which sealing means include glass as a bonding agent between the ceramic electrolyte element or a ceramic extension thereof and said metal housing or an intermediate metal member attached to the housing and wherein a protective niobium coating or foil is provided over the metal to protect the metal-glass interface at least in the region where it is exposed to sodium from the sodium compartment.
In particular, if a protective coating is employed, it may be preferable to apply this coating to a base metal member having a coefficient of expansion similar to that of coating material, which base metal member is then secured in the housing before the latter is sealed.
The electrolyte in a sodium sulphur cell is conveniently of tubular form and, as previously mentioned, an alpha-alumina extension, e.g. a flange may be secured to the beta-alumina tube, using for example a glass seal; this alpha-alumina flange may then be sealed to a cylindrical housing with the glass-metal seal. Conveniently in such a cell the sodium compartment is an annular region around the outside of the beta-alumina tube, and in this case, if the housing has a suitable coefficient of expansion, a niobium coating may be provided on the housing in the region of the seal to the alpha-alumina flange. Preferably however the niobium coating is provided on a base member, such as a corrosion-resistant nickel alloy, which has a coefficient of thermal expansion similar to that of the glass, alpha-alumina and niobium. A suitable base metal is a nickel-iron alloy such as that known as the aforementioned and described Nilo 42 or Nilo K. In one convenient form of construction having an outer cylindrical steel housing, a nickel-iron corrosion-resistant ring is welded to the open end of the housing to extend downwardly therein, this ring being coated with niobium at least in the region of the ring where the glass-to-metal interface is exposed to sodium.
A coating of niobium may be applied to such a base metal member by any convenient technique such as for example electro-plating or vapour deposition. The coating may be quite thin and a typical thickness might be of the order of 10 to 200 microns.
Instead of coating the ring with niobium, it may be more convenient to secure niobium foil to the ring, for example by electron beam welding along one edge of the foil, the foil being secured to the ring in a part thereof which is exposed to the sodium and the foil extending around the surface of the ring, conveniently close thereto, so as to extend into the glass and thereby cover the surface of the ring at the region of the glass-metal interface which is exposed to the sodium.
In another form of seal used in sodium sulphur cells where an annular alpha-alumina flange is secured to the open end of a beta-alumina electrolyte tube, an annular groove is formed in the alpha-alumina flange and a metal member, conveniently a controlled expansion nickel-iron alloy, is provided which is secured, for example by welding, to the end of a cylindrical steel housing, which controlled expansion metal member extends into the aforementioned annular groove and is secured by glass in that groove, this metal member, where it extends into the groove, being protected by niobium plating or by niobium foil as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 7 each show a form of seal between a beta-alumina tube and an outer metal housing for use in a sodium sulphur cell.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 there is shown diagrammatically part of a beta-alumina tube 10 in a sodium sulphur cell, the axis of the tube being indicated by the chain line X--X. The tube 10 is closed at its lower end and forms the container for the sulphur/polysulphides forming the cathodic reactant for the cell. Secured to the open end of this tube is an alpha-alumina flange 11 which is sealed to the beta-alumina tube 10 by a glass seal 12. The glass seal is formed, in this embodiment and in all the further embodiments described below, of a sodium-resistant glass such as an aluminate or alumino-borate glass. In the arrangement of FIG. 1, the sub-assembly is secured by glass 13 in an outer tubular housing 14 of a controlled expansion metal, e.g. Nilo 42, which, on its inner surface in the region of the seal, is coated with niobium, as shown at 15. A nickeliron corrosion-resistant ring 16 of controlled expansion material, as hereinbefore defined, is also secured in the seal assembly to provide a support for the cathode current collector and a closure for the cathodic compartment. The niobium coating 15 extends between the glass 13 and the housing 14 so protecting the glass-metal bond at the interface exposed to sodium vapour. It will be appreciated that, unless the alpha-alumina flange 11 is ground, a dimensional tolerance has to be allowed resulting in a gap 17 between the housing 14 and the flange 11. In this cell, the region 18 between the beta-alumina electrolyte tube and the outer housing 14 contains liquid sodium and sodium vapour at its upper end whilst the region 19 inside the beta-alumina tube contains the aforementioned cathodic reactant and also a cathodic current collector (not shown). Sodium vapour will penetrate through the gap 17 between the alpha-alumina flange 11 and the outer housing 14. The flange 11 is sealed to the housing 14 by the glass 13 to form a glassed-in compression joint, the metal-to-glass bond being protected by the niobium 15.
In FIG. 2, which shows a modified form of construction, the same reference characters are used as in FIG. 1 to indicate corresponding features. In FIG. 2, the housing 14 is formed of steel and a corrosion-resistant nickel-iron alloy ring 20 forming a controlled expansion member as previously defined is secured in the top of the housing 14, conveniently by welding around adjacent top edges of the housing 14 and ring 20 as shown at 21. As in FIG. 1, a controlled expansion nickel-iron annular member 16 is also secured in the seal assembly to provide a support for the cathode current collector and a closure for the cathodic compartment. The present invention is concerned primarily with the protection of the metal-to-glass bond in the presence of sodium vapour and, to give this protection, at least the lower inner surface of the ring 20 is plated with niobium, this plating extending, as shown at 22, at least over the part of the ring 20 where the glass-to-metal interface is exposed to the sodium vapour.
FIG. 3 shows a modification of the construction of FIG. 2 having, as before, a beta-alumina electrolyte tube 10 sealed to a cylindrical steel casing 14. In the arrangement of FIG. 2, no alpha-alumina flange is provided, the sealing being effected directly by glass 23. To protect the glass-to-metal bond, a controlled expansion nickel-iron ring 24 is secured inside the end of the housing tube, conveniently by welding around the top edge thereof as shown at 25 and this ring 24 is plated with niobium at least around the lower part thereof, as shown at 26, where the glass-to-metal interface is exposed to sodium vapour from the sodium compartment 18.
In the construction shown in FIG. 4, an alpha-alumina flange 30 is secured by glass 31 to the top end of a beta-alumina electrolyte tube 32. This assembly is contained within an outer steel cylindrical casing 33, the region 34 between the electrolyte tube and the housing containing sodium and sodium vapour. In the arrangement shown in FIG. 4 sealing of the sodium compartment is effected by means of a controlled expansion nickel-iron annular member 35 which is welded at its top end to the top of the casing 33. This member 35 is of generally annular form and has a downwardly-extending cylindrical portion 36 lying adjacent the inner surface of the steel housing, and inwardly-extending portion 37 and a further downwardly-extending portion 38 which extends into glass 39 in an annular groove 40 formed in the alpha-alumina flange 30. Also dipping into the glass in this groove is a further controlled expansion nickel-iron member 41 forming a support for a cathode current collector (not shown) and part of a seal for the cathodic region of the cell. To protect the metal-to-glass interface where it is exposed to the sodium vapour, niobium foil 43 is welded, for example by electron beam welding, to the aforementioned downwardly-extending portion 38, the foil extending completely around this member on the outer face thereof and extending downwardly into the glass 39 so as to prevent sodium vapour reaching the interface between the glass and the downwardly-extending member. The electrolyte tube, as in the previously-described embodiments, is closed at its lower end and thus separates the cathodic reactant-containing region 44 within the tube from the sodium-containing region 34 in the annular space between the housing 33 and the electrolyte tube 32.
FIG. 5 illustrates yet another construction of seal for a sodium sulphur cell. In FIG. 5 is shown part of a beta-alumina tube 50 sealed by glass 51 to an alpha-alumina flange 52 and contained within an outer steel casing 53. A controlled expansion nickel-iron ring 54 is secured by welding, as shown at 55, to the upper edge of the housing so as to extend downwardly within the housing. The upper face of the alpha-alumina flange 52 is shaped to leave a channel which is filled with glass 56. A cathode current collector support member 57 is also secured in this groove by the glass. This support member forms a closure for the top of tube 50. To protect the bond between the ring 54 and the glass from the sodium vapour, niobium foil 58 is secured by electron beam welding as shown at 59 with the weld extending completely around the ring 54, this connection being effected in the annular space between the ring 54 and the casing 53. The foil, in the embodiment illustrated, extends downwardly under the lower end of the ring and then upwardly into the glass as shown at 60 so as to prevent sodium vapour reaching the interface between the glass and the ring 55. The foil might alternatively be secured on the bottom edge of the member 54 or around the inner surface near the bottom edge of member 54. In each case it will prevent sodium vapour reaching the interface between the ring 54 and the glass. The beta-alumina tube 50 contains the cathodic reactant in the region 61 inside the tube, the sodium being in the annular region 62 between the electrolyte tube 50 and housing 53.
FIG. 6 shows yet another embodiment of the invention having a beta-alumina tube 70 which is secured by glass 71 within a cylindrical steel casing 72. As in the previous example, a controlled expansion nickel-iron alloy ring 73 is provided within the top of the tube and secured thereto by welding 74, this ring extending downwardly into the sodium compartment 75 below the level of the glass. Niobium foil 76 is secured by welding 77 to this ring 73 on the outer surface thereof and extends around the bottom thereof and upwardly into the glass 71 to protect the interface between the glass 71 and the ring 73 from exposure to sodium vapour. As in the previous embodiments, the tube 70 is closed at its lower end and contains the cathodic reactant in the region 78 inside the tube. A current collector support member 79 extends into the glass 71 and forms a top closure for the cathodic reactant region 78.
FIG. 7 illustrates yet another embodiment of the invention in which an annular foil element 80 of niobium is secured at 81 to a cylindrical casing 82 of controlled-expansion nickel-iron alloy and extends upwardly between an alpha-alumina flange 83 and the casing. The flange 83 is secured to a beta-alumina electrolyte tube 84 by glass as shown at 85 and further glass 86 seals the flange 83 to the casing 82, the niobium foil 80 protecting the metal-to-glass joint from sodium vapour in the gap 87 between the flange 83 and the casing 82. A current collector support member 88 of nickel-iron, forms also a top closure for the cathodic reactant region 89 within the tube 84, this tube separating the cathodic reactant from sodium in the annular region 90 between the electrolyte tube 84 and outer casing 82.
Although in the above-described embodiments, the cell has been described with an upright electrolyte tube sealed at its upper end, such cells may be used horizontally so that liquid sodium would be in contact with part of the glass seal. The protection extends around the whole of the interface exposed to sodium liquid or vapour.
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In an electrochemical cell, such as a sodium sulphur cell, having a solid ceramic sodium-ion permeable electrolyte forming part of the boundary of a sodium-containing region, to seal this region, the ceramic electrolyte or a ceramic extension thereof is sealed to a metal housing or metal closure element using glass with the glass-to-metal interface protected against the effect of sodium vapour by a niobium coating over the metal in the region where the interface is exposed to the sodium or this interface is protected from such exposure by niobium foil.
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FIELD OF THE INVENTION
This invention relates to a stabilised mount, e.g. for an antenna, camera, optical sensor or other surveillance apparatus. It was designed in connection with an antenna for use on a ship as part of a satellite communications system. It will be understood that it is necessary to isolate such an antenna from the effects of the pitch and roll of the ship.
DESCRIPTION OF THE PRIOR ART
One conventional method of stabilisation is to fix two spinning rotors to a platform carrying the antenna. The rotors produce a gyroscopic effect and are allowed to pivot freely about respective orthogonal axes. The effect of the rotors is to provide a restoring torque equal and opposite to that tending to destabilise the platform.
Experience has shown that the inclusion of slip rings and rotating joints in electrical connections between the antenna and ship is likely to result in reduced reliability, increased cost and undesirable signal loss. For these reasons continuous electrical links having sufficient flexibility to accommodate rotation about more than 360° are considered preferable in many circumstances. A problem associated with the use of such continuous electrical links is that, during the course of a voyage, the ship may turn through more than the maximum angle which can be accommodated by the flexibility of the links. It is therefore necessary to provide some form of detector to detect when the electrical links are twisted to their limits; and to provide some mechanism for "rewinding" the platform (i.e. rotating it about the azimuth axis through 360°) when such a detection is made. During this "rewinding" process gyroscopic action causes the rotors to pivot about their aforementioned orthogonal axes until they reach end stops (normally after pivotting through about 45°) whereupon the rotors cause a violent destabilisation of the platform; exactly the opposite effect of what is desired. Because of this violent destabilisation it may take a long while to regain a condition where the antenna is correctly tracking the satellite.
One known method of overcoming this problem is to effect the rewinding by rotating the antenna relative to the platform so that the rotors are not themselves affected by the rewinding process. This requires the provision of an expensive bearing sub assembly between the antenna and the platform. Another known method is to mount the rotor units on special bearings allowing the rotor units to rotate about axes parallel to the axis of rewind; and to provide a chain drive system so that the orientations of the rotor units are not changed during rewinding. This likewise involves additional expense.
BRIEF SUMMARY OF THE INVENTION
This invention provides a stabilised mount for an antenna comprising: a platform adapted to carry the antenna; a universal joint by which the platform is adapted to be mounted on a vehicle; means allowing the platform to be rotated about a first axis relative to the vehicle and the antenna to be rotated about a second axis relative to the platform so that the antenna is adjustable in azimuth and elevation; stabilisation rotors which rotate about third axes and are mounted on the platform in a manner such that they are allowed to pivot about the fourth and fifth orthogonal axes; means for detecting when the platform has rotated about the first axis relative to the vehicle to a certain limit; and locking means which respond to such a detection by locking the rotors at positions of rotation about the said fourth and fifth axes such that the third axes are parallel to the first axis.
By locking the rotors in this way it is possible to carry out the rewinding operation without causing the violent destabilisation previously referred to. The rewinding can be performed automatically either directly or indirectly in response to the aforementioned "detection." Where the rewind is initiated automatically it must be done in such a way as to ensure that rewinding is not commenced until after the locking means has locked the rotors.
In a preferred form of the invention the locking means includes a detent mechanism associated with the rotors and which engages to prevent rotation about the fourth and fifth axes when movement of the vehicle has caused the third axis to be parallel to the first axis. The rewinding operation can be commenced at a predetermined time after a "detection" sufficient to ensure engagement of the detent. Alternatively engagement of the detent can be arranged to produce a signal which initiates rewind.
One way in which the invention may be performed will now be described by way of example with reference to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a stabilised mount constructed in accordance with the invention and carrying an antenna;
FIG. 1A is an enlarged view of a platform and associated parts also shown in FIG. 1.
FIG. 2 is a detailed view of one of the two rotors also shown FIGS. 1 and 1A; and
FIG. 3 is a yet more detailed view of a detent mechanism also shown in FIG. 2.
DETAILED DESCRIPTION
Referring firstly to FIGS. 1 and 1A, there is shown a platform comprising three arms 1A,1B,1C mounted by a universal joint 2 to a shaft 3 which is free to move up and down in a pedestal 4 and is keyed to prevent rotation therein. A spring (not shown) in a pedestal 4 provides a shock absorbing action. The pedestal 4 is attached to a ship (also not shown). It is pointed out however that the apparatus could be used on other vehicles for use on land, in the air or in space.
Between the universal joint 2 and platform 1A,1B,1C is a bearing (not shown) allowing the platform to rotate about a first axis 5 which is shown vertical in FIG. 1.
The platform 1A,1B,1C is arranged to be driven in azimuth about axis 5 by a motor 6, pulley 7 drive belt 8 and a pulley 9, the latter being attached to the platform. The pulley 9 is also attached to a smaller pulley 9A which drives a belt 10 and thence a pulley 11. The latter is part of a potentiometer device which produces an output signal on line 12 indicating the current azimuth of the antenna.
The centre of gravity of the platform 1 and all the components attached to it is directly below the universal joint. This provides a vertical reference and tends to maintain the platform horizontal.
An antenna reflector 13 is mounted on a frame 14 which includes a shaft 15 journaled in the arm 1C of the platform for rotation about a second axis 16. The frame 15 has counterweights 15A to balance the weight of the reflector 13. The antenna is driven in elevation about the second axis 16 by a motor (not shown) having a pulley 17 linked by a belt 18 to a further pulley 19, the latter being fixed to the shaft 15. The motor is controlled by a signal on line 20. A potentiometer device (not shown), similar to that used to produce the azimuth signal on line 12, produces a signal on line 21 indicating the current elevation of the antenna.
The arms 1A and 1B of the platform carry U-shaped brackets 22 (FIG. 2) between the arms of which rotor assemblies 23 and 24 are pivotted. They are pivotted in bearings 25 about the orthogonal fourth and fifth axes 26 and 27 respectively.
FIG. 2 shows one rotor assembly 23 mounted in its bracket 22. The other rotor assembly 24 is identical except for the direction of rotation of the rotor and it will therefore not be described in detail. The assembly 23 comprises a motor 28 which drives a rotor 29 about an axis 30 which is the "third axes" referred to in the claims. The motor has, attached to it, a detent plate 31 (FIG. 3) having an edge 32 with a notch 33.
Fixed to the bracket 22 is a solenoid assembly 34 which is connected by a link 35 passing through a slot in the bracket 22 to a slider 36 carrying a roller 37 (FIG. 3) and guided by bearing in a bracket 38. In FIGS. 2 and 3 the slider 36 is shown in a position such that the roller 37 has entered the notch 33.
In operation the solenoid 34 is de-activated so that the rotor assembly 23 is able to pivot about the fourth axis 26 thereby providing the required stabilising effect.
A control system 39 (FIG. 1) controls the azimuth and elevation motors by signals on lines 41 and 20 to track the satellite, the current azimuth and elevation of the antenna being fed back to the control system 39 on lines 12 and 21.
The lines 12,20,21,40 and 41 pass through: a hollow vertical shaft forming the first axis, through universal joint 2, through shaft 3, and through pedestal 4 to the control system. A microwave link ML from an antenna feed horn (not shown) passes along the same path as do electrical links L1 and L2 which supply power to the rotor motors. When the signal on line 12 indicates that the antenna azimuth is displaced by 210° from a centre position where the electrical links between the antenna and the ship have no twist, the following sequence of events occurs under the control of the control system 39.
1. The control system 39 monitors communications traffic and sea state and selects a suitable time for rewinding having regard to the desirability of avoiding periods when there is a heavy flow of communications traffic and when the sea is rough. It is to be noted that, in this particular system, a further 60° of rotation in azimuth can take place before the platform 1A,1B,1C is prevented, by end stops, from further rotation which would otherwise cause undue twisting of the electrical links. The control system 39 is designed to ensure that a suitable time is chosen for rewind before that final limit is reached.
2. When a suitable time for rewind has been selected a signal is produced on line 40 to energise the solenoid 34 thus urging the roller 37 of the slider 36 into contact with the edge 32 of the detent plate 31.
3. The control system 39 then waits for a preset time interval of sufficient length to ensure that the movement of the ship will have caused the notch 33 to present itself to the roller 37: whereupon the roller 37 will drop into the notch 33 under the action of the solenoid 34.
4. After the preset time interval a signal is generated on line 41 to drive the antenna rapidly through 360° and then to stop.
The solenoid is then de-energised and, under the action of spring 42, the roller is removed from the slot to allow the rotors to resume their normal stabilising action.
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A stabilised mount (e.g. for an antenna) has two gyroscopic rotors mounted in such a way that they can pivot about orthogonal axes. Rewinding of the antenna (to avoid undue twisting of the electrical cables) is liable to cause a voilent destabilisation of the mount because of the gyroscopic action of the rotors. To prevent this destabilisation the rotors are locked against the aforementioned pivoting action during the rewinding procedure.
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BACKGROUND OF THE INVENTION
The invention relates to a limiting stop for the swinging angle of an arm which is movable around a bearing axis wherein one end of a strut is pivoted to the structural part which carries the bearing axis and wherein the other end of the strut is pivoted to the arm at a distance from the bearing axis.
Such limiting stops are frequently required for example in the development field of building fittings. They are used for example to limit the opening angle of open-out arms for windows and doors relative to the stationary frame and/or to the closure member.
The installation space which is available for the accommodation of such limiting stops is frequently relatively small. It is, however, important that the limiting stops durably and reliably fulfill their intended function.
According to the invention, there is provided a limiting stop of this type which requires relatively little installation space and has high functional reliability and is of a structurally simple design. Such a limiting stop is distinguished in that the strut consists of two structurally similar links, each having a longitudinal slot and a stop tongue which extends laterally from the plane of the link. the stop tongue of each link is slidably engaged for lengthwise movement in the elongated slot of the other link. The elongated slot of each link has a stop end which lies adjacent to its top tongue. The end of each stop tongue has laterally projecting supporting flanges which can enter the slot through an enlarged end of the slot which is distant from the stop end of the slot, and can be brought into supporting engagement with the longitudinal edges of the slot. The relative displacement of the links is less than the distance between the stop end and the enlarged end of the elongated slot of each link.
In accordance with one embodiment of the invention, the outwardly facing end of one link is pivoted on the structural part which carries the bearing axis. The outwardly facing end of the other link is pivoted on the arm. In another embodiment of the invention, the links of the strut consist of strip material with flat-rectangular cross section.
It is obvious that the links for forming a limiting stop in accordance with the invention can be easily and simply fabricated as punched and bent parts and that two of these links can be assembled through simple plug coupling connections into a strut which serves as a limiting stop which is adjustable lengthwise within given limits.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter of the invention is represented in the drawing in an exemplified embodiment in which:
FIG. 1 a top view of a limiting stop in operative connection with a carrying and guiding system for the closure member of a window, of a door or the like, the limit stop being shown in the operative stoping position, and
FIG. 2 a longitudinal cross section through the limiting stop mechanism of FIG. 1 but shown in the contracted or non-stoping position.
In FIG. 1 of the drawing, the stationary frame 1 of a window, of a door or the like, is shown in diagrammatically simplified presentation, that is, by means of a dot-dash line a planar closure member 3 is suspended within the frame and is swingably movable relative to the frame.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The carrying and guiding system which is generally indicated by the reference numeral 2 includes arm 4 which is suspended for swinging movement about a pivot pin axis 5 at a stationary frame 1. Two guide levers 8 and 9 are pivotally connected to the supporting arm 4 by means of two pivot pins 6 and 7 respectively. The levers 8 and 9 are of equal length. The guide levers 8 and 9 are, in turn, connected by pivot pins 10 or 11, respectively to a guide rail 12. The guide rail 12 is parallel with and secured to the closure member 3. The portion of the supporting arm 4 which lies between the pivot pins 6 and 7 forms, with the two guide levers 8 and 9 as well as with the guide rail 12, a guide parallelogram which is generally indicated by the reference numeral 13 Parallelogram 13 connects the closure member 3 with the stationary frame 1 The movement of the guide parallelogram 13 is affected through a control guide lever 14. One end of the control guide lever 14 is swingably suspended at the stationary frame at a bearing axis 5. The other end of the lever 14 is pivotally connected by a pivot pin 16 to the guide lever 8 at a point between the pivot pins 6 and 10. The control guide lever 14 affects the movement of the guide parallelogram 13 so that the closure member 3 is guided on its opening and closing motion along a path which is at least approximately limited by circular curves around a latent hinge axis which lies in the proximity of the side edge of the wing 3 adjacent to the bearing site.
In order to avoid injuries at the window or at the door as well as on the support and guide element system 2 it is necessary to limit the swinging angle for the supporting arm 4 around its bearing axis 5, for example to 90° to the plane of the stationary frame 1. A strut 17 functions as a limit stop for the swinging angle of the supporting arm 4. One end of the strut 17 is swingably suspended at a bearing axis 18 to the stationary frame 1. The other end of strut 17 engages the supporting arm 4, for example, through the hinge pin 6 at a point which is spaced from the bearing axis 5.
The strut 17 comprises two structurally similar overlapping links 19a and 19b. Each of the links 19a and 19b has an elongated slot and a stop tongue at one end of the link which extends at an angle to the plane of the link. The link 19a has a slot 20a and a stop tongue 21a. The link 19b has a slot 20b and a stop tongue 21b. The stop tongue of each link engages the elongated slot of the other link for lengthwise movement along the slot. The end of the elongated slot of each link which is nearest the stop tongue of the link acts as a stop end for the tongue of the other link. The slot 20a of link 19a has a stop end 22a and the slot 20b of the link 19b has a stop end 22b. In the fully extended position of the strut 17 as shown from FIG. 1, the distance between the pivot pins 6 and 18 is limited to the distance which is indicated by the reference numeral 23. When the strut 17 is in this extended position, the stop tongue 21a of the link 20a engages the stop end 22b in the elongated slot 20b of the link 19b, while the stop tongue 21b of the link 19b engages the stop end 22a in the elongated slot 20a of the link 19a as may clearly be seen in FIG. 1.
In order that the links 19a and 19b which form the strut 17 can be assembled and held together in a simple manner, each stop tongue 21a and 21b has, at its free end, a laterally projecting retaining flange. The stop tongue 21a has retaining flanges 24a and the stop tongue 21b has retaining flanges 24b. The retaining flanges 24a and 24b of each tongue are brought into supporting and holding engagement with the longitudinal edges of the elongated slot of the other link through an enlarged end at the end of the elongated slot which is remote from the stop end of the slot. Slot 20a has an enlarged end 25a and slot 20b has an enlarged end 25b.
In the contracted position as shown in FIG. 2, the distance between the axis 16 and 18 is indicated by the reference numeral 26. The difference between the distance 23 and 26 represents the relative displacement of the links 19a and 19b. The relative displacement of the links 19a and 19b between the extended position shown in FIG. 1 and the contracted position of FIG. 2 is less than the distance between the stop end and the enlarged end of the slot. A undesired and automatic uncoupling of the lashings 19a and 19b forming the strut 17 is thereby avoided in a simple manner.
The two links 19a and 19b are identical and can therefore be fabricated with the same tool, as punched and bent parts out of strip material of flat-rectangular cross section. It is important that the stop tongues 21a and 21b of the two links 19a and 19b respectively engage for lengthwise movement within their assigned elongated slots 20b and 20a respectively while the free ends of the strut 17 are held on the pivot pins 6 and 18 for lengthwise movement.
The utilization of the strut 17 as a limiting stop for the swinging angle of an arm which is movable around a bearing axis is not necessarily limited to the support and guide system 2 as shown in FIG. 1. The limiting stop which is formed through the strut 17 can be used wherever the object is to limit the swinging angle for an arm which is movable around a bearing axis relative to the structural part which carries a bearing axis.
after assembly of the links 19a and 19b into the strut 17, it is also possible to press into the enlarged ends 25a and 25b of the elongated slots 20a and 20b filler pieces, e.g. of plastics, in a detent-like manner in order to prevent undesired decoupling of the links.
SUMMARY OF THE INVENTION
A limit stop for the swinging angle of an arm 4 which is movable around a pivot pin 5, such as is used for example as open-out arm between the closure member 3 and the stationary frame of a window or a door. The limit stop requires only a small installation space , has high functional reliability and is of a structurally simple construction. For this purpose, one end of a strut 17 is fastened through a pivot pin 18 on the structural part which also carries the pivot pin 5. The other end of the strut 17 is pivotally connected by a pivot pin 6 to the arm 4 at a distance from the pivot pin 5. The strut 17 consists of two structurally-similar links 19a, 19b. Each link has an elongated slot and a stop tongue which is spaced from the stop tongue of the other link and which is also bent off from the plane of the links. The stop tongue of each link 19a, 19b is, in each case, inserted for lengthwise movement in the elongated slot of the other link. The stop end 22b or 22a of the elongated slot of each link lies adjacent the stop tongue of the link. The end of each stop tongue has laterally projecting retaining flanges (24a,24b) which can be brought into supporting engagement with the longitudinal edges of the elongated slots of the links (25a,25b) which is spaced from the stop end of the elongated slot. The relative displacement of the links 19a and 19b can be limited to a length which is less than the distance between the stop end 22a or 22b and the enlarged end 25a or 25b of the elongated slots 20a or 20b of each link 19a or 19b.
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A limiting stop for the swinging angle of an arm which is pivotally mounted on a fixed structure. The stop consists of a pair of parallel links which are connected for relative sliding motion between at contracted position and an extended position. At least one of the links has an elongated slot and the other link has a laterally projecting tongue which extends into the slot for movement along the slot. One end of the slot has a stopping surface which is engaged by the tongue when the links are in the extended position for determining the swinging angle of the arm.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to an electrical circuit assembly, in particular for a control device of a motor vehicle, comprising a first circuit board, at least one second circuit board and at least one mount for holding the second circuit board on the first circuit board whilst producing an electrical contact between the first and the second circuit board. The invention also relates to a control device comprising at least one electrical circuit assembly. The invention furthermore relates to a method for producing an electrical circuit assembly.
[0002] Electrical circuit assemblies of the type mentioned in the introduction are known from the prior art. By way of example, DE 692 10 365 T2 describes an electrical connector corresponding to the mount, by means of which connector printed circuit boards, for example, in other words circuit boards, can be electrically connected to one another. In this case, the first circuit board is a memory control board and the second circuit board is a single inline memory module (SIMM). The memory module is intended to be arranged perpendicularly with respect to the surface of the memory control board by means of the electrical connector. Contact connections to which the memory module is electrically connected in the inserted state are arranged in a slot of the electrical connector. The electrical contact between the memory module and the memory control board is produced via the contact connections. In the case of this assembly, provision is made for fixedly connecting the electrical connector to the memory control board, while the memory module can be inserted into the connector and can also be removed again from the latter. It is therefore provided that the electrical connector is designed for changing the memory module, while it always remains fixedly connected to the memory control board. It is often desirable, however, in particular in the case of control devices for motor vehicles, simultaneously to arrange a plurality of second circuit boards on the first circuit board and to produce the electrical contact between the first and the second circuit boards. In addition, often the second circuit board is intended already to be incorporated in a housing of the electrical circuit assembly before the first circuit board is inserted into said housing. For this reason, it is necessary to provide the second circuit board with a sufficient mechanical strength and, moreover, to equip it with a mount, by means of which it can be arranged in a positionally fixed manner in the housing in order to be able reliably to produce the electrical contact between the first and the second circuit board as soon as the former is inserted into the housing. That means that in many cases a permanent connection between the first circuit board and the mount and/or the second circuit board is not intended to be produced.
SUMMARY OF THE INVENTION
[0003] By comparison with the electrical circuit assembles known from the prior art, the electrical circuit assembly of the invention has the advantage that it increases the strength of the second circuit board, enables the latter to be fixed in a housing and can be embodied in such a way that there is no permanent electrical contact between the first and the second circuit board. This is achieved according to the invention by virtue of the fact that the second circuit board is preassembled on the mount, and the preassembled unit consisting of second circuit board and mount is connected to the first circuit board, wherein the mount and the second circuit board are arranged transversely, in particular at right angles, with respect to the first circuit board. Therefore, in contrast to the electrical circuit assemblies known from the prior art, it is not the case that firstly the mount is fixed on the first circuit board and then the second circuit board is inserted into the mount. Rather, it is provided that firstly the second circuit board is connected to the mount, such that the preassembled unit is present. The mount thus serves for increasing the strength of the second circuit board and the fixing of the second circuit board on a housing on or in which the electrical circuit assembly is provided. Afterward, the preassembled unit consisting of second circuit board and mount is connected to the first circuit board. The electrical contact between the first and the second circuit board is produced in this case. Both the mount and the second circuit board are intended to be arranged transversely with respect to the first circuit board. A right-angled arrangement is advantageously provided. The fixing of the preassembled unit on the first circuit board can be provided by means of the second circuit board, the mount or both. By way of example, contact elements of the second circuit board can be connected to the first circuit board, wherein the mount serves for support on the first circuit board. The electrical contact between the first and the second circuit board can be produced both directly and indirectly. In the former case, contact elements of the second circuit board are connected to contact elements of the first circuit board while in the latter case the mount likewise has contact elements that are connected to the contact elements of both the first and the second circuit boards.
[0004] One development of the invention provides for the preassembled unit to be connected to the first circuit board in a releasable manner. Consequently, there is no need for there to be a permanent connection between the preassembled unit, that is to say the second circuit board and/or the mount, and the first circuit board. Rather, it is provided that the preassembled unit, after having been connected to the first circuit board, is releasable again therefrom.
[0005] One development of the invention provides for the connection between the first circuit board and the mount and/or the fixing of the second circuit board to the mount to be produced by means of hot calking, screwing, clipping or press-fitting. Both for the connection between the first circuit board and the mount and the fixing of the second circuit board on the mount, it is possible to provide connections which are designed to be releasable—for example screwing, clipping or press-fitting—or permanent—for example hot calking In this case, the material of the first and of the second circuit board and of the mount is provided accordingly.
[0006] One development of the invention provides for the mount to be a die-cast component. The mount is particularly advantageous and cost-effective in terms of production if it is embodied as a die-cast component. During production in the die-casting method, holding elements of the mount can already be concomitantly formed. In this way, the mount can be produced in just one production step.
[0007] One development of the invention provides for the mount to comprise aluminum, zinc or magnesium or a plastic. The mount can be produced from aluminum, zinc or magnesium or comprise these substances, for example in the form of an alloy. The mount can also be produced from a plastic. These materials can be processed particularly advantageously in the die-casting method. It is advantageous if the materials have a good thermal conductivity in order that heat possibly arising at the second circuit board can be dissipated from the latter. Given an appropriate choice of material, therefore, the mount can also serve as a cooling device for the second circuit board.
[0008] One development of the invention provides a housing, in which the first circuit board, the second circuit board and/or the mount are arranged at least in regions. In this case, by way of example, one or a plurality of second circuit boards with mount can be arranged in the housing and subsequently connected to the first circuit board. On the other hand, it is also possible firstly to fix the first circuit board in the housing and then to introduce the second circuit board into said housing. In this case, it is not necessary for the first circuit board, the second circuit board and/or the mount to be arranged completely in the housing. Rather, they can also be provided outside the housing in regions. By way of example, the housing can have cutouts through which the second circuit board together with the mount are introduced into said housing and thus connected to the first circuit board. However, it can also be provided that the housing completely envelopes the first circuit board, the second circuit board and the mount and in this case is embodied as water-tight, in particular.
[0009] One development of the invention provides for the mount to be fixed together with the second circuit board on/in a housing. In other words, it is possible firstly to arrange the second circuit board together with the mount in the housing. In this case, a connection to, or an electrical contact with, the first circuit board is not yet necessary. This will be produced only at a later point in time.
[0010] One development of the invention provides for the preassembled unit to be fixed on/in the housing by means of screwing, clamping or adhesive bonding. The mount with second circuit board preassembled thereon, that is to say the preassembled unit, can be fixed on the housing in various ways. By way of example, releasable connections, such as screwing or clamping, but also permanent connections, such as adhesive bonding, for example, are provided. The fixing can be present either between the housing and the mount or between the housing and the second circuit board or both.
[0011] One development of the invention provides for at least two mounts to be provided, which are arranged at an angle with respect to one another. In this case, the at least two mounts can be embodied as an angle element, for example. That means that the mounts are either connected to one another via a holding element or embodied in one piece. Preferably, the mounts are in this case tilted about their vertical axis with respect to one another. The angle is therefore not equal to 0°, preferably equal to 90°. The mounts can either be connected to one another via the holding element or have connecting elements by means of which they can be fixed to one another.
[0012] One development of the invention provides for the electrical contact between the first and the second circuit board to be produced directly and/or via the mount. After the preassembled unit has been connected to the first circuit board, therefore, an electrical connection can be present directly between the first and second circuit boards. For this purpose, by way of example, both the first and the second circuit boards have contact elements which form the electrical contact after connection. It can also be provided that further contact elements are provided on/in the mount, which are connected both to contact elements of the first circuit board and to contact elements of the second circuit board and thus produce the electrical contact indirectly via the mount. In this case, the electrical contact between the second circuit board and the mount can be formed as early as after the preassembly of the preassembled unit, while the electrical contact with the first circuit board only arises with the connection of the preassembled unit to the first circuit board.
[0013] One development of the invention provides for the direct contact to be produced by means of a semi flexible connection, at least one press-fit pin, at least one spring element, a circuit board connector and/or soldering. Therefore, the electrical contact is also provided either via releasable or via unreleasable connections. One example of a releasable connection is the at least one spring element, for example an S spring element, and one example of an unreleasable connection is soldering. If the preassembled unit is intended to be arranged in the housing before the first circuit board, then it is recommended to produce the direct contact via the at least one press-fit pin or the at least one spring element. These connections can be produced by simply press-fitting or placing the first circuit board onto the contact elements of the second circuit board.
[0014] One development of the invention provides for the contact via the mount to be produced via at least one contact element. On or in the mount, therefore, at least one contact element is provided which, after preassembly and connection of the preassembled unit to the first circuit board, has an electrical contact both the first and with the second circuit board. Consequently, the first and the second circuit boards are then also electrically connected to one another.
[0015] One development of the invention provides for the contact element to make contact with the first circuit board by means of at least one spring element or at least one press-fit pin and with the second circuit board by means of at least one press-fit pin. The electrical contact with the second circuit board is therefore produced by means of the at least one press-fit pin. In this case, the press-fit pin can be designed such that it simultaneously serves for holding the second circuit board on the mount; in other words, the preassembly is realized by means of said pin. For making contact with the first circuit board, the mount has at least one spring element, for example an S spring element, or at least one press-fit pin. In this case, the spring element ensures simple demounting of the mount from the first circuit board if the connection between them is intended to be released. Both the spring element and the press-fit pin can consist of gold or comprise gold, that is to say be gold-plated.
[0016] The invention furthermore relates to a control device comprising at least one electrical circuit assembly in accordance with the above embodiments.
[0017] The invention also relates to a method for producing an electrical circuit assembly, in particular in accordance with the above embodiments, wherein the circuit assembly has a first circuit board, at least one second circuit board and at least one mount for holding the second circuit board on the first circuit board whilst producing an electrical contact between the first and the second circuit board. In this case, it is provided that the second circuit board is preassembled on the mount, and that the preassembled unit consisting of second circuit board and mount is connected to the first circuit board, wherein the mount and the second circuit board are arranged transversely, in particular at right angles, with respect to the first circuit board.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention is explained in greater detail below on the basis of the exemplary embodiments illustrated in the drawing, without the invention being restricted. In the figures:
[0019] FIG. 1 shows an electrical circuit assembly comprising a first circuit board, a second circuit board and a mount,
[0020] FIG. 2 shows a detail view of a preassembled unit consisting of the mount and the second circuit board,
[0021] FIG. 3 shows an arrangement composed of two mounts which are connected to one another and are arranged at an angle with respect to one another,
[0022] FIG. 4 shows a housing of the electrical circuit assembly, wherein two preassembled units are provided,
[0023] FIG. 5 shows a view of the housing with two preassembled units arranged therein, and the first circuit board which is to be inserted into the housing,
[0024] FIG. 6 shows an exploded drawing of the electrical circuit assembly comprising the housing, the preassembled units, the first circuit board and screws used for closing the housing,
[0025] FIG. 7 shows a detail view of the mount, wherein press-fit pins are provided for making contact with the second circuit board and S spring elements are provided for making contact with the first circuit board,
[0026] FIG. 8 shows the mount known from FIG. 7 in a view from below, such that contact areas for the S spring elements can be discerned, and
[0027] FIG. 9 shows a mount, wherein press-fit pins are provided for making contact both with the first and with the second circuit board.
DETAILED DESCRIPTION
[0028] FIG. 1 shows an electrical circuit assembly 1 consisting of a first circuit board 2 , a second circuit board 3 and a mount 4 . The second circuit board 3 is preassembled on the mount 4 , thus resulting in a preassembled unit 5 . In this case, the second circuit board 3 is fixed to the mount 4 for example by means of hot calking, screwing, clipping or press-fitting. Both the second circuit board 3 and the mount 4 are arranged at right angles with respect to the first circuit board 2 , that is to say that a vertical axis of the mount 4 is perpendicular to the first circuit board 2 . In the example illustrated in FIG. 1 , an electrical contact 6 is produced directly between the first circuit board 2 and the second circuit board 3 by means of contact elements 7 . The contact elements are embodied as press-fit pins 8 and arranged by means of a contact element holder 9 such that when the preassembled unit 5 is connected to the first circuit board 2 , the pressfit pins 8 can be pressed through contact cutouts 10 in the first circuit board 2 . The mount 4 forms contact areas 11 on its side that comes into contact with the first circuit board 2 , said contact areas serving to stabilize the second circuit board 3 . After the preassembled unit 5 has been connected to the first circuit board 2 , the contact areas 11 ensure that no tilting of the preassembled unit 5 or of the second circuit board 3 can occur. The connection between the preassembled unit 5 and the first circuit board 2 can be produced via the press-fit pins 8 , for example.
[0029] In addition, in the example illustrated in FIG. 1 , however, latching devices 12 are provided, which, with latching heads 13 , extend through latching cutouts (not visible here) in the first circuit board 2 upon the connection of the preassembled unit 5 to the first circuit board 2 , and produce a latching connection between the preassembled unit 5 and the first circuit board 2 . At least one electrical component 14 is provided on the second circuit board 3 and is electrically connected thereto, that is to say can be in electrical contact with the first circuit board 2 . The mount 4 substantially consists of two holding arms 15 which are connected to one another and which run parallel to the second circuit board 3 . The latching devices 12 are provided on the holding arms 15 . At the same time, the holding arms 15 can also have at least one insert (not illustrated here) for the second circuit board 3 , into which the latter can be inserted for preassembly. In the example illustrated, however, the preassembly is effected by means of holding elements 16 , which can be embodied analogously to the latching devices 12 , for example, and hold the second circuit board 3 on the mount 4 . Both the latching devices 12 and the holding elements 16 can be embodied, for example, as latching connection elements which can be latched in the mount 4 . That means that they have, in the part engaging into the mount 4 , latching elements that securely hold them in said part after insertion.
[0030] FIG. 2 shows the preassembled unit 5 consisting of mount 4 and second circuit board 3 without the first circuit board 2 illustrated in FIG. 1 . It can clearly be discerned that the press-fit pins 8 have a collar 17 , which serves together with the contact area 11 for insert delimitation during the connection of the preassembled unit 5 to the first circuit board 2 . During connection, therefore, both the contact area 11 and the collar 17 can be connected to the first circuit board 2 .
[0031] FIG. 3 shows two mounts 4 , on each of which a second circuit board 3 is preassembled. The mounts 4 are arranged perpendicularly to one another and are connected to one another—in particular in a releasable manner—by means of a connecting element 18 . The mounts 4 connected to one another by means of the connecting element 18 can therefore be jointly connected to the first circuit board 2 . Alternatively, it can also be provided that the mounts 4 are fixed to one another without the connecting element 18 , that is to say directly. By way of example, the mounts 4 can be embodied in one piece, in particular during a common production process.
[0032] FIG. 4 shows a first part 19 of a housing 20 , in which two mounts 4 with second circuit board 3 preassembled therein are arranged. The first part 19 of the housing 20 is embodied as a shell and can be closed by means of a second part 21 (not illustrated here), after the connection of the preassembled units 5 to the first circuit board 2 (likewise not illustrated here). In a front side of the housing 20 , a cutout 22 is provided in which, for example, a male connector strip of the first circuit board 2 can be arranged. In the example illustrated, the preassembled units 5 are fixed in the housing 20 by means of clamping.
[0033] FIG. 5 shows that the first part 19 of the housing 20 and the first circuit board 2 with male connector strip 23 fitted therein. The first circuit board 2 can be arranged in the housing 20 in such a way that the male connector strip 23 is located in the cutout 22 . In this case, an electrical contact is produced between contact elements 24 of the first circuit board 2 and the contact elements 7 , which are embodied here as contact areas 25 for S spring elements. Consequently, after the positioning of the first circuit board 2 in the housing 20 , the first circuit board 2 and the second circuit board 3 are electrically connected to one another. By virtue of the production of the electrical contact 6 by means of the S spring elements and the contact areas 25 —which form a releasable connection—the first circuit board 2 can be removed from the housing 20 again in a simple manner.
[0034] FIG. 6 shows an exploded illustration of the circuit assembly 1 . It can be discerned that the housing 20 consists of a first part 19 and a second part 21 , which are connected to one another by means of screws 26 . The preassembled units 5 —each consisting of mount 4 and second circuit board 3 —are arranged in the first part 19 of the housing 20 , then the first circuit board 2 is placed thereon and the housing 20 is closed. In the assembled state, that is to say with the housing 20 closed, the first circuit board 2 is pressed onto the preassembled units 5 , whereby the electrical contact 6 is produced.
[0035] FIG. 7 shows a mount 4 , without preassembled second circuit board 3 . The mount 4 has a press-fit pin 27 for making contact with and for holding the second circuit board 3 . Bearing areas 28 are likewise provided, on which the second circuit board 3 bears after preassembly. Insert openings 29 for receiving the holding elements 16 in a latching manner are likewise provided. The holding elements 16 are introduced into the insert openings 29 in a latching manner after the preassembly of the second circuit board 3 on the mount 4 . Guide lugs 30 are provided on the mount 4 , which allow accurate positioning during introduction of the mount 4 into the housing 20 . The mount 4 illustrated in FIG. 7 has bushes 31 , through which screws (not illustrated) can extend for the purpose of fixing the mount 4 to the first circuit board 2 . In this way, the accurate positioning is provided by means of the guide lugs 30 and secure and releasable fixing to the first circuit board 2 is also provided by means of the bushes 31 .
[0036] FIG. 8 shows the mount 4 known from FIG. 7 in a view from below. Contact areas 25 for the S spring elements, via which the electrical contact 6 with the first circuit board 2 is intended to be produced, are clearly discernable here. The contact areas 25 for the S spring elements are electrically connected to the press-fit pins 27 , such that the electrical contact 6 between first circuit board 2 and second circuit board 3 is produced via the mount 4 .
[0037] FIG. 9 shows an alternative embodiment of the mount 4 known from FIGS. 7 and 8 . In contrast to FIGS. 7 and 8 , the mount 4 illustrated here, for the purpose of making contact with the first circuit board 2 , does not have contact areas 25 for S spring elements, but rather press-fit pins 28 . In contrast to the mounts 4 illustrated in FIGS. 1 and 2 , therefore, here as well the electrical contact 6 is not produced directly between first circuit board 2 and second circuit board 3 , but rather via the mount 4 or the press-fit pins 28 . For the further properties of the mount 4 illustrated here, reference should be made to the explanations concerning FIGS. 7 and 8 .
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The invention relates to an electrical circuit assembly ( 1 ), particularly for a control device of a motor vehicle, having a first circuit board ( 2 ), at least one second circuit board ( 3 ) and at least one holder ( 4 ) for holding the second circuit board ( 3 ) on the first circuit board ( 2 ), producing an electrical contact ( 6 ) between the first ( 2 ) and the second ( 3 ) circuit boards. According to the invention, the second circuit board ( 3 ) is preassembled on the holder ( 4 ) and the preassembled unit ( 5 ), comprising the second circuit board ( 3 ) and holder ( 4 ), is connected to the first circuit board ( 2 ), wherein the holder ( 4 ) and the second circuit board ( 3 ) are arranged crosswise, particularly at a right angle, to the first circuit board ( 2 ). The invention furthermore relates to a control device and to a method for producing an electrical circuit assembly ( 1 ).
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[0001] The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/000,694, entitled NUTT SO RUFF SCRUB BAR and filed on Oct. 29, 2007. The disclosure of that application is hereby fully incorporated by reference herein.
BACKGROUND
[0002] The present disclosure relates to exfoliating products that are used to exfoliate various parts of the body.
[0003] Exfoliation is a process in which the surface layer of dead skin cells is removed. While the skin will exfoliate on its own, manual exfoliation removes dead skin cells and increases circulation. The result is softer, smoother, healthier glowing skin. Exfoliation is especially helpful for oily skin because oil clogs skin pores, which could cause unsightly acne blackheads. Exfoliation also helps dry skin, which otherwise tends to look dull. Because dead skin cells generally accumulate faster than natural exfoliation, the skin's natural exfoliating ability and moisture absorption ability are inhibited. Regular exfoliation thus allows the skin to absorb more moisture, reduce fine lines from wrinkles, and decrease acne.
[0004] Traditional means of exfoliation include using pumice stones, corn/callus removers, chemical peels, and facials. Pumice stones operate as an abrasive, and therefore do not provide gentle skin exfoliation. Corn/callus removers typically include a sharp blade, which can be dangerous if improperly used. Such situations are common because corn/callus removers are typically used with running water, such as in a sink or during a shower. Wet hands increase the chance that the remover will slip from the hand and cause cuts. Chemical peels and facials can be expensive. Patients can also have severe skin reactions, such as breakouts and skin redness.
[0005] There are some over-the-counter products that attempt to aid exfoliation as well. Many of these products come in the form of gels or pastes. As a result they can be messy to use. Some of these over-the-counter products can also be harsh to sensitive skin. In addition, gels and pastes are hard to use without making a mess, and are especially difficult to use in the shower.
[0006] It would be desirable to provide an exfoliation product that can be used on various parts of the body, depending on skin sensitivity, and can be used on a daily basis if desired. Such a product should also be effective at removing dead skin, but gentle on the skin.
BRIEF DESCRIPTION
[0007] Disclosed in various embodiments is a scrub bar that uses natural ingredients to exfoliate the skin gently and effectively. The bar form allows a person to use the scrub bar in the shower and easily cleanse themselves.
[0008] Disclosed in embodiments is a scrub bar comprising three ingredients: powdered or crushed nuts; powdered or crushed oats; and glycerin. In some embodiments, the scrub bar consists of the nuts, oats, and glycerin.
[0009] In particular embodiments, the nuts comprise from about 6 to about 12.5 weight percent of the scrub bar. The oats may also comprise from about 6 to about 12.5 weight percent of such embodiments.
[0010] In other embodiments, the oats comprise from about 6 to about 12.5 weight percent of the scrub bar.
[0011] In some embodiments, the nuts comprise about 6.25 weight percent of the scrub bar and the oats comprise about 6.25 weight percent of the scrub bar. In additional embodiments, the nuts comprise about 9.375 weight percent of the scrub bar and the oats comprise about 9.375 weight percent of the scrub bar. In yet other embodiments, the nuts comprise about 10 weight percent of the scrub bar and the oats comprise about 10 weight percent of the scrub bar.
[0012] The glycerin may comprise from about 75 to about 88 weight percent of the scrub bar.
[0013] Desirably, the nuts and oats have a particle size of 1 mm or less. Preferably, the nuts used in the scrub bar are almonds.
[0014] The scrub bar may not contain animal fats or oils, methyl alcohol or ethyl alcohol, a colorant, or an odorant.
[0015] Sometimes, the oats and nuts are evenly dispersed throughout the glycerin. However, the oats and nuts may also be preferentially located near a surface of the scrub bar.
[0016] Disclosed in other embodiments is a scrub bar comprising: from about 6 to about 12.5 weight percent of powdered or crushed nuts; from about 6 to about 12.5 weight percent of powdered or crushed oats; and from about 75 to about 88 weight percent of glycerin; wherein the weight ratio of nuts to oats is about 1:1.
[0017] Also disclosed is a method for producing a scrub bar. Liquid glycerin is provided in a container. The powdered or crushed nuts and oats are added to the liquid glycerin. The liquid glycerin is mixed to disperse the nuts and oats, thereby forming a mixture. The mixture is poured into a mold and cooled to form the scrub bar.
[0018] These and other non-limiting characteristics of the present disclosure are more particularly described below.
DETAILED DESCRIPTION
[0019] The scrub bar of the present disclosure comprises (a) powdered or crushed nuts; (b) powdered or crushed oats; and (c) glycerin. In some embodiments, the scrub bar consists of the nuts, oats, and glycerin only.
[0020] In embodiments, the powdered or crushed nuts are each present in the amount of from about 6 to about 12.5 weight percent of the scrub bar. The term “nut” refers generally to a kernel found within a shell or husk. Although any nut can be used, generally peanuts are avoided due to peanut allergies amongst the general population. Desirably, crushed or powdered almonds are used. Other nuts which may be useful in the scrub bar of the present disclosure include almonds, walnuts, chestnuts, pecans, cashews, macadamia nuts, and pistachios.
[0021] In embodiments, the powdered or crushed oats are each present in the amount of from about 6 to about 12.5 weight percent of the scrub bar.
[0022] The nuts and oats are powdered or crushed. In other words, they are processed from their original intact state into a less than intact state where they have particle sizes of from 0.1 mm to 3 mm. Desirably, the nuts and oats, once powdered or crushed, can pass through a sieve having a sieve size of 1 mm, i.e. so that the particle size is 1 mm or less. For example, the powdered or crushed nuts/oats can be generally obtained by passing intact nuts/oats through a food processor, running through a sieve, and returning the un-passed material through the food processor again. The powdered or crushed nuts/oats generally have a consistency similar to that of a powder or soft sand.
[0023] Depending on the degree of abrasiveness desired in the scrub bar, the amount of nuts and oats will vary. Generally, the nuts and oats are present in a weight ratio of about 1:1 nuts:oats. Generally, the greater the amount of nuts and oats, the more abrasive the scrub bar will be. In specific embodiments, the nuts comprise about 6.25 weight percent of the scrub bar and the oats comprise about 6.25 weight percent of the scrub bar. In other embodiments, the nuts comprise about 9.375 weight percent of the scrub bar and the oats comprise about 9.375 weight percent of the scrub bar. In still other embodiments, the nuts comprise about 10 weight percent of the scrub bar and the oats comprise about 10 weight percent of the scrub bar. The nuts and oats provide an abrasive surface for effective exfoliation, but are gentle to the skin, unlike harsh pumice.
[0024] The glycerin serves as a base in which the nuts and oats are dispersed. The glycerin may comprise from about 75 to about 88 weight percent of the scrub bar. As used here, the term “glycerin” does not refer to the specific chemical compound also known as glycerol(1,2,3-propanetriol). Instead, the term “glycerin” refers to the common soap base generally formed from the reaction of a fat and lye, which can contain ˜7-20% pure glycerol.
[0025] Desirably, the scrub bar contains natural ingredients. In particular, the scrub bar does not contain animal fats or oils, methyl alcohol or ethyl alcohol, colorants, or odorants in specific embodiments.
[0026] The oats and nuts may be evenly dispersed throughout the glycerin. In some embodiments, the oats and nuts are preferentially located near a surface of the scrub bar. Put another way, a majority (by weight) of the oats and nuts in the scrub bar are dispersed close to a surface of the scrub bar (rather than within the internal volume of the bar). The dispersion of the oats and nuts within the glycerin can be controlled by methods known in the art.
[0027] The scrub bar of the present disclosure can be made using methods known in the art. For example, the nuts and oats may be pulverized or powdered using devices such as a food processor. The degree of powdering can be controlled, for example, by using a sieve to obtain the desired powder size. Next the glycerin is provided in a liquid form, for example, by melting a solid glycerin base. The powdered or crushed nuts/oats are then added to the liquid glycerin. The liquid glycerin can be mixed, for example, by stirring, to disperse the nuts and oats within the glycerin. The degree of dispersion can be controlled by the amount of stirring. The mixture of glycerin, nuts, and oats can then be poured into a mold. The mold is then cooled to harden the scrub bar. Cooling is generally passive, in other words, the mold is simply left at room temperature until the liquid mixture has been cooled and hardens. If desired, active cooling, such as with water or air, may be used as well. The scrub bar is then removed from the mold by turning the mold upside down.
[0028] Exemplary embodiments include a soap bar containing 0.5 ounces of a nut/oat mixture with 3.5 ounces of glycerin; a soap bar containing 0.75 ounces of a nut/oat mixture with 3.25 ounces of glycerin; and a soap bar containing 0.75 ounces of a nut/oat mixture with 3 ounces of glycerin.
[0029] Although particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the claims as filed or as they may be amended are intended to embrace all such alternatives, modifications, variations, improvements, and substantial equivalents.
BRIEF DESCRIPTION OF THE DRAWING
[0030] FIG. 1 is a tilted side view that shows the top and bottom of the exfoliating scrub bar of the present invention.
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An exfoliating scrub bar for various parts of the body is made from natural ingredients that exfoliate the skin gently and effectively. The scrub bar comprises powdered or crushed nuts; powdered or crushed oats; and glycerin. The combination of ingredients allows a person to gently exfoliate different parts of the body depending on the location and/or skin sensitivity. The scrub bar provides the user with an effective tool for exfoliation that allows for the removal of dead skin cells.
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BACKGROUND OF THE INVENTION
The invention concerns an oil-sealed vane-type rotary vacuum pump with an oil pump whose suction chamber is fitted with feeds for oil and gas. By loading the oil with gas, preferably with air, a reduction in the noise levels is attained when the vacuum pump is operating.
A vane-type rotary vacuum pump having the characteristics of the features of patent claim 1 is known from DE-A-3922417. The feed lines for gas and oil leading into the suction chamber of the oil pump according to the state-of-the-art are so arranged, that the oil pump will initially only pump air and then only oil. This is attained by designing the distance between the intake openings for air on the one hand and for oil on the other hand to be so great, that the intake opening for the oil is opened after the vane which follows next has already separated the circulating swept volume from the air intake opening. Simultaneous suction of air and oil is not possible. The known solution thus requires the use of an oil pump having at least three vanes which are arranged evenly spaced along its circumference. Only this ensures that oil will be sucked in also while the pump is running up. Without a supply of oil, both the oil pump and also the vane-type rotary vacuum pump which is to be supplied with oil would be damaged after a short time. A vane-type oil pump with three vanes is involved and thus costly. Moreover, the quantity of the air or quantity of the oil which is sucked in may only be influenced with the aid of nozzles with the risk that these might block.
From EU-A-474066 it is known to mix--in an oil pump which is also of the vane type--the supplied gas and oil before it enters into the oil pump. A Venturi nozzle is used for this. In the area of the Venturi nozzle the air flow and the oil flow run in parallel. Thus a pressure drop is created so that the oil is entrained with the gases. This solution too, is engineering wise relatively involved in particular because the use of a Venturi nozzle.
SUMMARY OF THE INVENTION
It is the task of the present invention to design an oil-sealed vacuum pump of the aforementioned kind in such a manner that its supply with a mixture of gas and oil is especially simple.
This task is solved through the present invention by the characteristic features of patent claim 1. In a vacuum pump designed according to the present invention, it is no longer required to employ oil pumps of the vane type and/or means which are independent of the oil pump to mix oil and air. Because initially oil and then a mixture of air and oil is sucked in simultaneously, gas and air are already mixed efficiently in the oil pump. Suction of oil at first and then oil as well as air is performed and it is released into the same swept volume. Oil pumps equipped with vanes in which the swept volumes need to separate the intake openings for air and gas at all times are no longer required. Furthermore, a special advantage is, that that quantity of the sucked in share of the air can be controlled by the angle of the intake opening for the air. The use of nozzles for the purpose of influencing the air/oil shares in the pumped mixture can be dispensed with.
BRIEF DESCRIPTION OF THE INVENTION
Further advantages and details of the present invention shall be explained on the basis of the design example presented in drawing FIGS. 1 and 2.
Drawing FIG. 1 a longitudinal section through a design example for a vane-type rotary vacuum pump according to the present invention and
Drawing FIG. 2 a top view on to a bearing section in which the oil pump is accommodated.
The presented pump 1 comprises the subassemblies casing 2, rotor 3 and drive motor 4.
DESCRIPTION OF THE INVENTION
The casing 2 has substantially the shape of a pot with an outer wall 5, with the lid 6, with an inner section 7 and the suction chambers 8, 9 as well as rotor-mounting bore 11, with end section 12 and bearing section 13 which complete suction chambers 8, 9 at their face sides. The axis of the rotor-mounting bore 11 is designated as 14. Located between outer wall 5 and inner section 7 is the oil chamber 17, which during operation of the pump is partly filled with oil. Two oil level glasses 18, 19 (maximum, minimum oil level) are provided in the lid 6 for checking the oil level. An oil fill and oil drain are not shown. The oil sump is designated as 20.
Located within the inner section 7 is the rotor 3. It is designed as a single part and has two anchoring sections 21, 22 on the face side and a bearing section 23 located between anchoring sections 21, 22. The anchoring sections 21, 22 are equipped with slots 24, 25 for two vanes 26, 27. The presentation according to drawing FIG. 1 is so selected that the respective spaces between the vanes 28, 29 are placed in the plane of the drawing figure. The vane-mounting slots 25, 26 are each milled from the corresponding face side of the rotor so that precise slot dimensions can be attained in a simple manner. The bearing section 23 is located between anchoring sections 21, 22. Bearing section 23 and rotor-mounting bore 11 form the only bearing for the rotor.
Anchoring section 22 and the related suction chamber 9 have a greater diameter compared to anchoring section 21 with the suction chamber 8. Anchoring section 22 and suction chamber 9 form the high vacuum stage. During operation, the inlet of the high vacuum stage 9, 22 is linked to the intake port 30. The discharge of the high vacuum stage 9, 22 and the inlet of the forevacuum stage 8, 21 are linked via casing bore 31, which extends in parallel to the axes of the suction chambers 8, 9. The discharge of the forevacuum stage 8, 21 opens into the oil chamber 17. There the oil containing gases quite down and leave the pump 1 through the discharge port 33. For reasons of clarity the inlet and discharge openings of the two pumping stages are not shown in drawing FIG. 1. The casing 2 of the pump is preferentially assembled from as few parts as possible. At least the two suction chambers 8, 9 and the wall sections 5, 7 surrounding the oil chamber 17, should be made of a single piece.
Coaxial with axis 14 of the rotor-mounting bore 11, the bearing section 13 is equipped with a bore 35 for a rotor drive. This rotor drive may consist directly of the shaft 36 of the driving motor 4. In the design example presented in drawing FIG. 1, a coupling piece 37 is provided between the free face side of the driving shaft 36 and the rotor 3. The way in which the coupling piece 37 is coupled to the driving shaft 36 on the one hand and the rotor on the other hand is not described in detail. This is explained in DE-A-43 25 285 in greater detail.
The presented pump is equipped with an oil pump. This consists of the suction chamber 45 embedded in the bearing section 13 from the side of the motor and the oval eccentric 46 rotating in said suction chamber. In contact with the eccentric is a stopper 47 which is tensioned by spring 48. The eccentric 46 of the oil pump is part of the coupling piece 37. It is linked either firmly or by a positive fit--with axial play only--to the coupling piece 37.
In the presented design example with oil pump 45, 46, the bearing section 13 is equipped on its side which faces the motor 4 with a circular recess 58 in which a disc 59 is located. This disc is maintained in place by the casing 61 of the driving motor 4. Said disc is equipped with a central bore 62, which is penetrated by the shaft 36 of the driving motor 4. Moreover, it is the task of the disc 59 to limit the suction chamber 45 of the oil pump 45, 46.
Air from the oil chamber 17 is supplied via a first channel 64, and oil from the oil sump 20 is supplied via a second channel 65 to the oil pump 45, 46. The mixture of air and oil exiting the oil pump enters into channel 66 which opens into the rotormounting bore 11 (opening 67). At the level of opening 67, the bearing journal 23 is equipped with a radial through-hole 68 from which a longitudinal bore 69 with a nozzle 70 branches off in the direction of the space between the vanes 28. The position of the opening 67 of channel 66 on the one hand, and the opening of the radial bore 68 in the bearing journal 23 on the other hand, is so selected that oil from channel 66 can only briefly enter into bore 68 when the vanes 26 attain their T-position. If the radial bore 68 fully penetrates the bearing journal 23, there exist two openings, so that each time when the vanes attain their T-position a link is provided to oil pump 45, 46. During each turn of the rotor 3, the vanes 26 attain this T-position twice. In this position the space between the vanes 28 has its smallest volume. The mixture of oil and air which is injected by the nozzle briefly into the space between the vanes 28 flows through the space between the vanes 28 and enters into suction chamber 8 without being pressurised. For this, the inside of the lid 12 is equipped with a groove 71 which extends from the space between the vanes 28 into the suction chamber 8. In order to ensure that the space between the vanes 28 is permanently linked to the suction chamber 8, the free face side of anchoring section 21 is additionally equipped with a turned groove 72.
If the vacuum pump designed according to the present invention is a single-stage pump, then the significant share of the mixture of oil and air will flow via the bores 66, 68, 69 into the space between the vanes 28 and into the suction chamber 8, and from there it will return to the oil chamber 17. Only a very small share of the oil will enter into the bearing slot between rotor-mounting bore 11 as well as bearing journal 23 supplying this bearing with lubricating oil. It flows through the bearing slot and then also enters into the suction chamber 8. If the vacuum pump is - as presented in the design example according to drawing FIG. 1--of the two-stage type, then a third partial flow of mixed oil and air will enter into the bearing slot of bearing 11, 23 in the direction of the high vacuum stage 9, 22. Would the mixture of oil and air enter the high vacuum stage, then the air contained in the oil would impair the ultimate pressure characteristic of the vacuum pump. Therefore, a degassing step is performed along the passage from the opening 67 of channel 66 to suction chamber 9 of the high vacuum stage. For this, the bearing journal 23 is equipped with a circular groove 74 at the level at which a bore 75 opens which is linked with the intermediate vacuum (bore 31).
Shown in drawing FIG. 2 is a top view on to bearing section 13. The circular suction chamber 45 of the oil pump is embedded in the bearing section 13. Located in the suction chamber is rotor 46 of oval shape, against which the stopper 47 rests from below. The direction of rotation is marked by an arrow. Initially an oil feed 81 opens into the swept volume which increases in volume (to the right of stopper 47). This feed is formed by way of a groove in the surface of the bearing section 13 and extends from the opening of the oil supply channel 65 (drawing FIG. 1) to the suction chamber 45. It is linked via a branching groove 82 to the rear of the stopper 47 supplying the stopper with lubricating oil and providing a means of pressure relief within the slot of the vane.
An air feed 83 offset by the angle a opens into suction chamber 45. This feed too, is groove-shaped and is linked to the air feed channel 64 (drawing FIG. 1).
The sucked in mixture of oil and air is pumped by the corresponding swept volume to discharge 84. This is formed by a groove which is linked to the channel 66 (drawing FIG. 1).
The share of the air in the mixture of oil and air depends on the magnitude of the angle α (azimuth distance between air feed and oil feed). By changing this angle α it is possible to influence this share. The magnitude of the angle α is between 5° and 90°, preferably between 30 to 40. It is important that--and this applies also to rotors which differ in design from the one presented--during the a significant part of the suction phase both oil as well as air are sucked in.
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The invention concerns an oil-sealed vane-type rotary vacuum pump (1) with a rotor (3) and an oil pump (45, 46) whose suction chamber is fitted with feeds (64, 65) for gas and oil. In order to simplify the supply of a gas/oil mixture to the vacuum pump, the invention proposes that the gas and oil feeds (64, 65) are disposed in such a way that initially only oil and subsequently both oil and air are aspirated into the volume swept by the oil pump (45, 46) as it rotates.
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This application is a continuation, of application Ser. No. 203,993 now abandoned, filed Jun. 8, 1988 which is a continuation of now abandoned application Ser. No. 812,505, filed Dec. 23, 1985.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the production of polysaccharides by microbial fermentation of carbohydrates, and, more especially, to such production carried out in an oil-in-water emulsion fermentation medium.
2. Description of the Prior Art
Heteropolysaccharides or biopolymers obtained by fermentation of a carbohydrate utilizing bacteria of the genus Xanthomonas or Arthrobacter, fungi of the genus Sclerotium, and other microorganisms of like type, are useful for a wide variety of industrial applications by virtue of their thickening and viscosity increasing properties.
The production of xanthan gum by aerobic fermentation in aqueous media has been described in numerous patents. See, for example, U.S. Pat. Nos. 3,000,790, 3,020,206, 3,391,060, 3,433,708, 4,119,546, 4,154,654, 4,296,203, 4,377,637 and French Patent No. 2,414,555.
At the onset of production, the fermentation medium may contain approximately 15 to 50 g/liter of polysaccharide. Industrially, it is very difficult to exceed a concentration of 30 to 35 g/liter without the need for special measures. In effect, the increase in the viscosity of the reaction medium at the rate of the formation of the polysaccharide slows the transfer of oxygen and reduces fermentation. Even if the reactors are equipped with powerful stirring means, which are costly in view of their energy consumption, it is very difficult to insure adequate aeration and agitation of the reaction mass to permit an increase in the polymer concentration.
In order to increase the gum concentration, it has recently been proposed to carry out the fermentation in the form of an emulsion or dispersion of the aqueous nutrient medium in an oil, such as to reduce the viscosity of the wort and facilitate the transfer of oxygen. Compare published European Applications Nos. 00/58,354, 00/74,775 and 00/98,473.
However, it would appear to be preferable to effect a first stage of microorganism growth in an essentially aqueous nutrient medium prior to the introduction of the oil and the establishment of the water-in-oil emulsion. Once the water-in-oil emulsion is formed, it becomes difficult to regulate the pH of the dispersed aqueous phase and the formation of acid by-products presents the risk of inhibiting the growth of the microorganism. It is certainly possible to conduct the operation in a buffered medium, but the presence of the buffer may be harmful to the quality of the final product. Furthermore, stabilized water-in-oil emulsions are very difficult to dilute, which is disadvantageous in light of the need for the direct application of these emulsions, for example, in the exploitation of subterranean well formations/petroleum deposits.
SUMMARY OF THE INVENTION
Accordingly, a major object of the present invention is the provision of an improved fermentation process for the production of heteropolysaccharides, and one specifically designed to more readily effect the growth of microorganisms within an emulsified fermentation medium.
This invention also relates to the preparation of stable biopolymer emulsions containing up to about 60% of biopolymer.
Briefly, the present invention features the production of polysaccharides by microbial fermentation of an aqueous nutrient medium, and wherein an oil is dispersed in the aqueous medium in a manner such that an oil-in-water emulsion is formed, the fermentation being carried out therein.
DETAILED DESCRIPTION OF THE INVENTION
More particularly according to the present invention, the continuous aqueous phase may comprise any of the aqueous fermentation media well known to this art, and described, for example, in U. S. Pat. Nos. 3,391,060 and 3,433,708, and in French Patent No. 2,414,555. The "conventional" fermentation medium contains a carbohydrate source that may be a sugar or another carbohydrate, an organic and/or inorganic source of nitrogen, together with trace elements, and, if necessary, growth factors. The sugar concentration, such as glucose or saccharose, may range from 10 to 100 g/liter and may even attain a value of 150 to 200 g/liter.
The microorganism employed as the agent of fermentation may be selected from among those bacteria known to ferment carbohydrates, such as described in Bergey's, Manual Of Determinative Bacteriology (8th edition, 1974, Williams and Wilkins Co., Baltimore). Suitable for this purpose are, for example, Xanthomonas begoniae, Xanthomonas campestris, Xanthomonas carotae, Xanthomonas hedera, Xanthomonas incanae, Xanthomonas malvacearum, Xanthomonas papaveri cola, Xanthomonas phaseoli, Xanthomonas pisi, Xanthomonas vasculorum, Xanthomonas vericatoria, Xanthomonas vitians, Xanthomonas pelargonii; the bacteria of the genus Arthrobacter, and more particularly the species Arthrobacter stabilis and Arthrobacter viscosus; of the genus Erwinia; of the genus Azotobacter, and more particularly the species Azotobacter indicus; of the genus Agrobacterium, and more particularly the species Agrobacteriam radiobacter, Agrobacterium rhizoqenes and Agrobacterium tumefaciens. Fungi belonging to the genus Sclerotium may also be used.
Among these microorganisms, Xanthomonas campestris is preferably used.
With respect to the oil phase, any mineral or vegetable oil immiscible with water may be employed, for example, the isoparaffins, deodorized kerosene, hydrocarbons having a high boiling point, preferably higher than 150°-200° C., rapeseed oil, soybean oil, corn oil, sunflower oil, peanut oil, and the like. It is desirable that the proportion of the oily phase constitute less than 30% of the total fermentation medium, preferably 1 to 18% thereof, and even more preferably 3 to 16%.
The dispersion and stabilization of the oily phase in the aqueous phase are favorably influenced by the presence of surface active agents, preferably nonionic surfactants, the HLB value of which is preferably less than 11, and even more preferably ranges from 6 to 11, with this value being attained by use of a single surfactant or mixture thereof. The selection and the amount of the surfactant necessary to obtain a continuous aqueous phase can readily be determined by those skilled in this art as a function of the particular oil and its concentration in the medium.
Exemplary of the nonionic surface active agents, generally compounds obtained by the condensation of an alkylene oxide with an aliphatic or alkyl-aromatic organic compound may be utilized. Representative surfactants which do not inhibit the growth of microorganisms are the polyoxyethylene alkylphenols, polyoxyethylene alcohols, polyoxyethylene fatty acids, polyoxyethylene triglycerides, polyoxyethylene esters of sorbitan and fatty acids.
All of the surface active agents may be used either alone or as an admixture thereof. All or a portion of the surfactant or surfactants may be introduced, depending upon their affinity, into either the oily phase or the continuous aqueous phase.
To carry out the process of the invention, it is advisable to separately sterilize the oil phase and the aqueous phase. After sterilization and cooling, the oil phase may be mixed into the aqueous phase contained in the fermentation tank or else each of the phases may be continuously introduced into the fermentation vessel under agitation. A stable emulsion is immediately formed. Seeding and fermentation are then carried out in a conventional manner, with aeration and agitation. Over the course of the fermentation the pH may be maintained at its optimum value by injection therein of an alkaline or ammoniacal solution. It is also possible to periodically or continuously make additions of the medium necessary for growth.
After fermentation and depending upon the application intended, the emulsion may be used as is, or the aqueous phase may be separated from the oil phase by destabilization in a manner known, per se, and the wort may be used in the raw or crude state, or else the polysaccharide may be precipitated, for example, by the addition of a lower alcohol such as isopropanol, either with or without the aid of a mineral salt. The precipitated polysaccharide is separated, washed clean of the oil adsorbed on the fibers thereof, and then dried and optionally ground. A ready-to-use powder is obtained in this fashion.
In one particular embodiment of the process of the invention, the emulsion obtained upon completion of the fermentation process is concentrated to eliminate the water until an emulsion is produced containing 8 to 60% by weight, and preferably 15 to 60% by weight, of polysaccharides with respect to the weight of the product emulsion. In this embodiment of the invention, the amount of oil used for the fermentation must be calculated as a function of the dry solids content upon completion of the fermentation. It is preferable that the amount of oil in the final emulsion does not exceed 45% by weight of the total medium.
The water may be eliminated, for example, by evaporation or distillation, optionally under partial pressure. It is possible to eliminate a portion of the oily phase in at mixture with water, whether or not azeotropic. Ultrafiltration may also be carried out using conventional methods and equipment, with the obvious condition of selecting a porous hydrophilic membrane having pores that are sufficiently small to prevent the passage of the biopolymer through the membrane.
Ultrafiltration assures the preservation of emulsions having a continuous aqueous phase. Concentration by ultrafiltration has the further advantage of maintaining the inorganic salt content of the aqueous phase at values close to those existing in the initial wort, regardless of the polymer content.
In another embodiment of the invention, the emulsions may be initially concentrated by ultrafiltration and then by a different operation, for example, evaporation or distillation.
Without departing from the scope of the invention, bactericides, enzymes, or other additives intended for a particular application, may be added to the emulsions obtained, provided that said additives do not adversely affect the stability of the emulsion.
The advantage of the subject process vis-a-vis the inverse emulsion system are as follows:
(1) The possibility of effecting the growth of microorganisms in an emulsified medium at a normal reaction rate--the growth of the microorganisms is not disturbed by the emulsion;
(2) Energy savings during the growth phase, as the power required to agitate the fermentation medium is lower;
(3) The possibility of easily regulating the pH of the aqueous phase; and
(4) The possibility of concentrating the emulsions without inversion of the phases and without precipitation of the polysaccharide.
The oil-in-water emulsions obtained according to the process of the invention may be used in any application requiring viscosified aqueous liquids, such as the building, paint, cosmetic, plant protection, petroleum, etc., industries. They have the advantage that they may be used directly for the preparation of dilute aqueous solutions without having to be subjected to phase inversion. They disperse very well in water, their rate and degree of dissolution being at least equal to that of the initial wort. They remain pumpable and stable over a very broad range of concentration. Their viscosity is substantially less than that of an aqueous solution containing an equivalent amount of biopolymer, such that it is possible to provide pourable or pumpable emulsions having high polysaccharide concentrations in the aqueous phase.
In view of these advantages the emulsions of the invention are particularly appropriate for use in the petroleum field and for the formulation of aqueous liquids intended for the assisted recovery of petroleum.
In order to further illustrate the present invention and the advantages thereof, the following specific examples are given, it being understood that same are intended only as illustrative and in nowise limitative.
In said examples to follow, a general procedure was utilized, wherein:
(i) The aqueous nutrient medium was charged into the fermentation vessel and sterilized,
(ii) The oil, optionally containing the surfactant or surfactants, was sterilized and poured, under agitation, into the aqueous solution contained in the fermentation vessel at room temperature, and
(iii) The medium was seeded with a preculture of Xanthomonas campestris on a MY saccharose nutrient solution at 10 g/l.
EXAMPLE 1
In a 20 liter fermentation tank, 14 liters of a sterile oil/water emulsion containing 6.25% by volume of the oily phase and 93.75% of the aqueous phase, were seeded with 210 g of the preculture.
______________________________________Composition of the aqueous phase:______________________________________(i) Dextrose: 61 g/l(ii) Yeast extract: 7 g/l(iii)Na.sub.2 HPO.sub.2 : 2.35 g/l(iv) (NH.sub.4).sub.2 PO.sub.4 : 2.2 g/l(v) MgSO.sub.4.7H.sub.2 O: 0.35 g/l______________________________________Composition of the oil phase:______________________________________(i) Dearomatized aliphatic hydrocarbon 70% by weight(Exsol D 100 marketed by Esso Chimie)(ii) Ethoxylnonylphenol 30% by weight(67/33 mixture of Cemulsol NP4 andCemulsol NP 17 - trademarks ofSFOS Company)HLB value: 11______________________________________Fermentation conditions:______________________________________Temperature: 28° C.pH controlled at 7 by the addition ofsodium hydroxideAgitation: 400 rpmAeration from 0 to 17 hours: 0.24 VVM17 to 23 hours: 0.48 VVM23 to 90 hours: 0.98 VVMFermentation until all of the sugar is depletedDuration: 90 hours______________________________________
The growth of the microorganism population and the resistivity of the medium over time are reported in Table I which follows.
The amount of active material obtained was 425 g (30.3 g/kg), representing a yield with respect to sugar of 56%.
The viscosity of the emulsion upon completion of fermentation was 8.1 Pa·s (Brookfield viscosity 20° C.-No. 4 needle-30 t/min).
EXAMPLE 2
The procedure of Example 1 was repeated, using an initial fermentation medium composed of 29% by volume of Exsol D 100 hydrocarbons and 71% of the aqueous phase having the following composition:
(i) Dextrose: 64 g/l
(ii) Yeast extract: 9.24 g/l
(iii) Na 2 HPO 4 : 3.08 g/l
(iv) (NH 4 ) 2 PO 4 : 3.08 g/l
(v) MgSO 4 ·7H 2 O: 0.35 g/l
No surfactant was added.
The operating conditions were identical to those of Example 1, except for the aeration which was constant at 0.98 VVM. Fermentation was for 85 hours, at which stage no more sugar was present.
The growth of the microorganism population and the resistivity of the fermentation medium are also reported in Table I.
330 g of active material were obtained, representating a yield of 51.3% with respect to the sugar. The vicosity of the final emulsion was 10.2 Pa·s (same conditions as in Example 1).
EXAMPLE 3
The initial oil/water emulsion was formed from 14.125 liters of the aqueous phase and 0.875 liters of the oily phase.
Composition of the aqueous phase
(i) Saccharose: 85 g/l
(ii) Soluble corn extract: 25.5 g/l
(iii) MgSO 4 ·7H 2 O: 0.28 g/l
The oily phase contained 70% by weight of rapeseed oil and 30% ethoxynonylphenols (CEMUSOL NP4).
HLB value: 9
The medium was seeded as in Example 1.
Fermentation conditions
Temperature: 28° C.
pH controlled at 7 by the addition of sodium hydroxide
Agitation from 0 to 17 hours: 390 rpm
17 to 24 hours: 500 rpm
24 to 84 hours: 600 rpm
Aeration from 0 to 17 hours: 0.92 VVM
17 to 84 hours: 1.4 VVM
Average power dissipated: 6.09 KW/m 3
After 84 hours, 51 g xanthan gum per kg of the medium had been produced. Yield/saccharose consumed: 64%.
The consistency K (by Ostwald's law) of the medium was 37 Pa•s and the pseudoplasticity index n was 0.195.
By comparison, an aqueous wort containing 48.5 g/kg polymer had a consistency K of 70 Pa•s and an index n of 0.24.
Fermentation was continued for 113 hours. 66 g/kg polymer were obtained.
Yield/saccharose consumed: 83%
EXAMPLES 4 and 5
Two fermentations were carried out in an oil/water emulsion containing 0.875 liter of the oily phase and 14.125 liters of the aqueous phase.
The composition of the fermentation medium was as follows:
(i) Saccharose: 8%
(ii) Soluble corn extract (CSL): 4%
(iii) MgSO 4 · 7H 2 O: 0.05%
(iv) Oil: 3.5%
(v) Surfactants: 1.5%
The oily phase consisted of rapeseed oil and natural fatty ethoxyalcohols (CEMULSOL AS 5-SFOS Company) and, for Example 4, of aliphatic hydrocarbons (EXSOL D 89) and ethoxynonylphenols (50/50 mixture of CEMULSOL NP 4 and CEMULSOL NP 17) for Example 5.
Fermentation conditions were as follows:
Temperature: 28° C.
______________________________________ Aeration Agitation______________________________________0-17 hours: 0.92 VVM 390 rpmafter 17 hours: 1.39 VVM 500 rpmafter 41 hours: 1.39 VVM 500 rpm (Ex. 4) 600 rpm (Ex. 5)______________________________________
Fermentation was continued until all of the saccharose was consumed:
______________________________________Results: Example 4 Example 5______________________________________Duration: 68 hours 80 hoursActive material: 47.4 g/kg 51 g/kgYield/saccharose: 60% 64%______________________________________
Using 1 ml of a preculture of Xanthomonas campestris on a MF culture medium having 10 g/liter saccharose, 100 ml of an emulsified oil/water medium contained in a 500 ml Erlenmeyer flask were seeded.
The aqueous phase common to both examples was identical to that of Example 3.
The composition of the oily phase was varied. Each flask contained 95% by weight of the aqueous phase and 5% by weight of the oily phase. The flask was agitated using a rotating agitator, revolving at 220 rpm at an amplitude of 5 cm, and incubated at 28° C. for 89 hours.
The results are reported in Table II.
TABLE I______________________________________ Xanthomonas ResistivityAging UFC/ml of emulsion ν · cm(hours) Ex. 1 Ex. 2 Ex. 1 Ex. 2______________________________________ 0 1.6 × 10.sup.8 3.9 × 10.sup.7 216 --17 4 × 10.sup.8 3 × 10.sup.9 216 --23 8 × 10.sup.9 5.4 × 10.sup.9 370 35443 7 × 10.sup.8 2 × 10.sup.10 216 35466 4 × 10.sup.8 1.2 × 10.sup.10 216 27790 1 × 10.sup.8 185 262______________________________________
TABLE II__________________________________________________________________________Example 6* 7 8 9 10 11 12 13 14__________________________________________________________________________Oil** Rapeseed 3.5 3.5 Soybean 3.5 3.5 Exsol D 80 3.5 3.5 Isopar M 3.5 3.5Surfac- Cemulsol NP 4 1.5 1 0.75 1 0.75tant** Cemulsol NP 17 0.5 0.75 0.5 0.75(g) Cemulsol R 5 1.35 Cemulsol T 0.15 Cemulsol NP 5 1.5 Cemulsol AS 5 1.5pH 6.75 6.2 6.5 6.55 6.35 6.3 5.75 6 5.9Viscosity*** (mPa · s) 9,600 11,700 7,400 8,700 11,100 7,000 10,500 12,900 12,900Sugar consumed (g/l) 45.6 49.5 60.5 47.2 48.4 54.5 63.3 62.2 67.1Polymer (g/kg) 32.4 41.3 33.8 35 36 35.9 41.2 41.2 42.8Yield/sugar consumed 71 83 89 74 74 66 65 66 64__________________________________________________________________________ *Control no oil **Exsol D 80 Aliphatic hydrocarbons, Esso Chimie Isopar M: Isoparaffins Esso Chimie Cemulsol NP 4, NP 5, NP 17: ethoxynonylphenols, Societe SFOS Cemulsol R5, AS 5, T: ethoxyoleocetyl alcohols, Societe SFOS ***Brookfield, 20° C., needle No. 4, 30 t/min
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims, including equivalents thereof.
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Heteropolysaccharide biopolymers well adopted as thickening agents are improvedly produced by microbially fermenting a carbohydrate nutrient medium, said nutrient medium comprising an oil-in-water emulsion of a discontinuous oily phase dispersed within a continuous aqueous phase.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is concerned with new anti-reflective compositions and via fill compositions for use in the manufacture of microelectronic devices. These compositions include a polymer and a styrene-allyl alcohol polymer dispersed in a solvent system.
[0003] 2. Description of the Prior Art
[0004] 1. Anti-Reflective Coatings
[0005] Integrated circuit manufacturers are consistently seeking to maximize substrate wafer sizes and minimize device feature dimensions in order to improve yield, reduce unit case, and increase on-chip computing power. Device feature sizes on silicon or other chips are now submicron in size with the advent of advanced deep ultraviolet (DUV) microlithographic processes.
[0006] However, a frequent problem encountered by photoresists during the manufacturing of semiconductor devices is that activating radiation is reflected back into the photoresist by the substrate on which it is supported. Such reflectivity tends to cause blurred patterns which degrade the resolution of the photoresist. Degradation of the image in the processed photoresist is particularly problematic when the substrate is non-planar and/or highly reflective. One approach to address this problem is the use of an anti-reflective coating applied to the substrate beneath the photoresist layer.
[0007] Compositions which have high optical density at the typical exposure wavelengths have been used for some time to form these anti-reflective coating layers. The anti-reflective coating compositions typically consist of an organic polymer which provides coating properties and a dye for absorbing light. The dye is either blended into the composition or chemically bonded to the polymer. Thermosetting anti-reflective coatings contain a crosslinking agent in addition to the polymer and dye. Crosslinking must be initiated, and this is typically accomplished by an acid catalyst present in the composition.
[0008] While these anti-reflective coatings are effective at lessening the amount of light reflected back into the photoresist, most prior art anti-reflective coatings are lacking in that they do not have a sufficiently high etch rate. As a result, prior art anti-reflective coatings present significant limitations which make them difficult or impossible to use on submicron (e.g., 0.3 μm) features.
[0009] 2. Fill Compositions
[0010] The damascene process, or the process of forming inlaid metal patterning in preformed grooves, is generally a preferred method of fabricating interconnections for integrated circuits. In its simplest form, the dual damascene process starts with an insulating layer which is first formed on a substrate and then planarized. Horizontal trenches and vertical holes (i.e., the contact and via holes) are then etched into the insulating layer corresponding to the required metal line pattern and hole locations that will descend down through the insulating layer to the device regions (if through the first insulating layer, i.e., a contact hole) or to the next metal layer down (if through an upper insulating layer in the substrate structure, i.e., a via hole). Metal is next deposited over the substrate, thereby filling the trenches and the holes and forming the metal lines and interconnect holes simultaneously. As a final step, the resulting surface is planarized (e.g., by the known chemical-mechanical polish (CMP) technique) and readied to accept another damascene structure.
[0011] During the dual damascene process, the contact and via holes are typically etched to completion prior to the trench etching. Thus, the step of trench etching exposes the bottom and sidewalls (which are formed of the insulating or dielectric layer) of the contact or via holes to over-etch which can deteriorate contact with the base layer. An organic material is typically used to partially or completely fill the via or contact holes and to protect the bottom and sidewalls from further etch attack. These organic fill materials can also serve as a bottom anti-reflective coating (as discussed above) to reduce or eliminate pattern degradation and linewidth variation in the patterning of the trench layer, provided the fill material covers the surface of the dielectric layer.
[0012] Fill materials which have high optical density at the typical exposure wavelengths have been used for the past several years. However, most prior art materials have limited fill properties. For example, when the prior art compositions are applied to the via or contact holes formed within the substrate, the films formed by the compositions tend to be quite thin on the substrate surface immediately adjacent the holes, thus leading to undesirable light reflection during subsequent exposure steps. Also, the flow properties of the composition tend to be lacking in that the composition does not completely flow into via and contact holes, resulting in inadequate protection of those holes.
[0013] There is a need in the art for contact or via hole fill materials which provide complete coverage at the top of via and contact holes. Furthermore, this material should properly flow into the via and contact holes to protect the base during etching and prevent degradation of the barrier layer and damage to the underlying metal conductors. There is also a need for improved anti-reflective coatings which can be effectively utilized to form integrated circuits having submicron features while also absorbing light at the wavelength of interest.
SUMMARY OF THE INVENTION
[0014] The present invention broadly comprises new fill compositions and anti-reflective coating compositions that are useful for the manufacture of microelectronic devices.
[0015] In more detail, the compositions comprise at least one styrene-allyl alcohol polymer and preferably at least one further polymer other than the styrene-allyl alcohol polymer. The composition should comprise from about 1-10% by weight styrene-allyl alcohol polymer, more preferably from about 1-6% by weight styrene-allyl alcohol polymer, and even more preferably from about 1-4% by weight styrene-allyl alcohol polymer, based upon the total weight of the composition taken as 100% by weight.
[0016] The styrene-allyl alcohol polymer should comprise from about 40-90% by weight styrene, preferably from about 60-82% by weight styrene, and more preferably from about 70-81% by weight styrene, based upon the total weight of the styrene-allyl alcohol polymer taken as 100% by weight. Also, the styrene-allyl alcohol polymer should comprise from about 10-60% by weight allyl alcohol, preferably from about 18-40% by weight allyl alcohol, and more preferably from about 19-30% by weight allyl alcohol, based upon the total weight of the styrene-allyl alcohol polymer taken as 100% by weight.
[0017] In one embodiment, the molar ratio of styrene to allyl alcohol in the composition is from about 0.4:1 to about 4:1, preferably from about 1:1 to about 2.7:1, and more preferably from about 1.2:1 to about 2.5:1. The weight average molecular weight of the styrene-allyl alcohol polymer is preferably from about 1000-10,000 Daltons, and more preferably from about 1000-5000 Daltons. Two particularly preferred commercially available styrene-allyl alcohol polymers are SAA-100 and SAA-101 (available from Lyondell Chemical).
[0018] In those embodiments where another polymer (hereinafter referred to as “additional polymer”) is used along with the styrene-allyl alcohol polymer, preferred additional polymers include those selected from the group consisting of novolaks, acrylics, celluloses, polyacrylics (e.g., polyacrylic acid), polystyrenes (e.g., polystyrene maleic anhydride), and mixtures thereof. The weight average molecular weight of these additional polymers is preferably from about 1000-100,000 Daltons, and more preferably from about 1000-70,000 Daltons. Preferably, the composition comprises from about 0.5-10% by weight of this additional polymer, more preferably from about 0.5-4% by weight, and even more preferably from about 0.5-3% by weight, based upon the total weight of the composition taken as 100% by weight. The weight ratio of styrene-allyl alcohol polymer to additional polymer in this embodiment is preferably from about 10:90 to about 90:10, and more preferably from about 30:70 to about 90:10.
[0019] The compositions are formed by simply dispersing or dissolving the styrene-allyl alcohol polymer(s) (in quantities as set forth above) in a suitable solvent system, preferably at ambient conditions and for a sufficient amount of time to form a substantially homogeneous dispersion. Preferred solvent systems include a solvent selected from the group consisting of propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether (PGME), propylene glycol n-propyl ether (PnP), 2-heptanone, N-methylpyrollidinone, ethyl lactate, and mixtures thereof. Preferably, the solvent system has a boiling point of from about 100-180° C., and more preferably from about 118-175° C. The solvent system should be utilized at a level of from about 80-98% by weight, and preferably from about 90-97% by weight, based upon the total weight of the composition taken as 100% by weight.
[0020] Any additional ingredients are also preferably dispersed in the solvent system along with the styrene-allyl alcohol. For example, the inventive compositions can further comprise a crosslinking agent, a catalyst, and an additional polymer as discussed above. The crosslinking agent can be separate from the polymer(s) present in the composition or, alternately, the polymer(s) can include “built-in” crosslinking moieties. Preferred crosslinking agents include aminoplasts (e.g., POWDERLINK® 1174, Cymel® products). The crosslinking agent or moieties should be present in the composition at a level of from about 0.2-2.5% by weight, and preferably from about 0.3-1.8% by weight, based upon the total weight of the composition taken as 100% by weight. Thus, the compositions of the invention should crosslink at a temperature of from about 180-220° C., and more preferably from about 190-210° C.
[0021] Preferred catalysts include those selected from the group consisting of p-toluenesulfonic acid, bisphenol-A, 4,4′-sulfonyldiphenol, pyridinium p-toluenesulfonate, and mixtures thereof. The catalyst should be present in the composition at a level of from about 0.02-0.45% by weight, and preferably from about 0.05-0.35% by weight, based upon the total weight of the composition taken as 100% by weight.
[0022] It will be appreciated that a number of other optional ingredients can be included in the composition as well. Typical optional ingredients include light attenuating compounds, surfactants, and adhesion promoters.
[0023] The method of applying the fill or anti-reflective coating compositions to a substrate (e.g., a silicon wafer) simply comprises applying a quantity of a composition hereof to the substrate surface by any conventional application method (including spin-coating). Advantageously, after the composition is applied to the hole, it is not necessary to subject it to a first stage bake process (i.e., heating the composition to its reflow temperature) so as to cause the composition to flow into the contact or via holes. That is, the styrene-allyl alcohol sufficiently improves the flow properties of the composition that this is not needed as was the case with prior art compositions.
[0024] After the desired coverage is achieved, the resulting layer should be heated to at least about the crosslinking temperature (e.g., 120-225° C.) of the composition so as to cure the layer. The degree of leveling of the cured material in any contact or via holes should be at least about 85%, preferably at least about 90%, and more preferably at least about 95%. As used here, the degree of leveling is determined as follows (where 100% means that complete leveling was achieved):
Degree of leveling = ( 1 - ( height of meniscus “ M ” ) height “ H ” of the hole ) × 100 ,
[0025] wherein “M” and “H” are measurements taken from the cured material as shown in FIG. 1 where 10 represents the cured material in the hole 12 . Specifically, “H” represents the height of the particular hole, and “M” represents the meniscus of the composition in the hole.
[0026] The thickness of the cured fill material layer on the surface of the substrate adjacent the edge of a contact or via hole should be at least about 50%, preferably at least about 55%, and more preferably at least about 65% of the thickness of the film on the substrate surface a distance away from the edge of the contact or via hole approximately equal to the diameter of the hole.
[0027] Anti-reflective coatings according to the invention have a high etch rate. Thus, the anti-reflective coatings have an etch selectivity to resist (i.e., the anti-reflective coating layer etch rate divided by the photoresist etch rate) of at least about 0.9, and preferably at least about 1.2, when HBr/O 2 (60/40) is used as the etchant. Additionally, at 193 nm the inventive anti-reflective coating layers have a k value (i.e., the imaginary component of the complex index of refraction) of at least about 0.25, and preferably at least about 0.35, and have an n value (i.e., the real component of the complex index of refraction) of at least about 1.5, and preferably at least about 1.6. That is, a cured layer formed from the inventive composition will absorb at least about 97%, and preferably at least about 99% of light at a wavelength of 193 nm.
[0028] Furthermore, the inventive anti-reflective coatings will be substantially insoluble in typical photoresist solvents (e.g., ethyl lactate). When subjected to a stripping test, the inventive anti-reflective coating layers will have a percent stripping of less than about 5%, and preferably less than about 1%. The stripping test involves puddling a solvent (e.g., ethyl lactate) onto the cured film for 5-10 seconds, followed by spin drying at 5000 rpm for 30 seconds to remove the solvent. The film is then baked on a hotplate at 100° C. for 30 seconds. The film thickness is measured at multiple points on the wafer using ellipsometry. The amount of stripping is the difference between the initial and final average film thicknesses. The percent stripping is:
% stripping = ( amount of stripping initial average film thickness ) × 100.
[0029] A photoresist can be applied to the cured material, followed by drying (soft bake), exposing, post-exposure baking, and developing the photoresist. Following the methods of the invention will yield precursor structures for dual damascene and other microlithographic processes which have the foregoing desirable properties.
[0030] Finally, the present invention also provides a method of adjusting the flow of a subject composition, regardless of whether that composition is an anti-reflective coating composition, a fill composition, or some other type of composition. In this method, one or more flow characteristics (e.g., viscosity) is evaluated by a known method to determine whether it is suitable for its intended use. If it is not, a quantity of a styrene-allyl alcohol polymer is mixed with the subject composition in sufficient quantities to obtain the desired flow characteristic. It will be appreciated that this quantity will depend upon the nature of the subject composition, but can easily be determined by one of ordinary skill in the art by observing the changes in the flow characteristics upon mixing of the styrene-allyl alcohol polymer with the composition.
[0031] After mixing the styrene-allyl alcohol polymer(s) with the subject composition, it is preferred that the flow characteristic of interest be re-evaluated, and the mixing and re-evaluating steps be repeated until the desired flow characteristics are achieved. Styrene-allyl alcohol polymers have been discovered to be particularly useful for improving and increasing the flowability of a composition so that it evenly flows over a surface, even when the surface is highly topographic.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] [0032]FIG. 1 is a cross-sectional view of a substrate having via holes formed therein where the holes are filled with a fill composition;
[0033] [0033]FIG. 2 a is a scanning electron microscope (SEM) photograph depicting a cross-sectional view of a silicon wafer coated with a fill composition according to the invention as described in Example 1;
[0034] [0034]FIG. 2 b is another SEM photograph depicting a cross-sectional view of a silicon wafer coated with the fill composition of Example 1;
[0035] [0035]FIG. 3 is another SEM photograph depicting a cross-sectional view of a silicon wafer coated with the fill composition described in Example 2;
[0036] [0036]FIG. 4 is another SEM photograph depicting a cross-sectional view of a silicon wafer coated with a fill composition as described in Example 3;
[0037] [0037]FIG. 5 is a further SEM photograph depicting a cross-sectional view of a silicon wafer coated with a fill composition as described in Example 4 wherein the wafer contains isolated vias;
[0038] [0038]FIG. 6. is a further SEM photograph depicting a cross-sectional view of a silicon wafer having dense vias and coated with the fill composition described in Example 4;
[0039] [0039]FIG. 7. is another SEM photograph depicting a cross-sectional view of a silicon wafer having isolated vias which are partially filled with the fill composition of Example 5;
[0040] [0040]FIG. 8. is yet another SEM photograph depicting a cross-sectional view of a silicon wafer having dense vias which are partially filled with a fill composition as described in Example 5;
[0041] [0041]FIG. 9 is a series of SEM photographs depicting a cross-sectional view of a silicon wafer having 0.13 μm dense L/S coated with the composition described in Example 6 and a commercially available photoresist composition; and
[0042] [0042]FIG. 10 is a series of SEM photographs depicting a cross-sectional view of a silicon wafer having 0.13 μm dense L/S coated with the composition described in Example 7 and a commercially available photoresist composition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLES
[0043] The following examples set forth preferred methods in accordance with the invention. It is to be understood, however, that these examples are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention.
Example 1
[0044] In this procedure, 5 g of SAA-101 polymer (a styrene-allyl alcohol copolymer from Lyondell Chemical, weight-average molecular weight: 2,500) was mixed with 0.5 g of POWDERLINK® 1174 (a crosslinking agent obtained from Cytec Industries, Inc.), 0.10 g of p-toluenesulfonic acid (TSA) and 181.07 g of PGME. A polymer solution was obtained after stirring for 2 hours. The solution was ion exchanged for two hours to minimize metals and filtered twice with a 0.1 μm end point filter.
[0045] The resulting composition was coated onto silicon wafers having vias by spin-coating at 400 rpm for 5 seconds followed by a cast spin at 1500 rpm for 60 seconds. The wafer was then baked at 205° C. for 60 seconds. Good surface coverage (400 to 900 Å) and full fill (1 μm) in vias with a diameter of 0.20 μm and a depth of 1.0 μm were obtained as evidenced by the SEM photographs shown in FIGS. 2 a and 2 b.
Example 2
[0046] About 20 g of ARC-DUV42-6 (an acrylic anti-reflective coating, available from Brewer Science, Inc.) was blended with 30 g of the solution prepared in Example 1. The mixture was stirred for one hour and filtered through a 0.1 μm end point filter to yield a dual damascene via fill composition. Silicon chips having vias were coated with the composition by spin-coating at 400 rpm for 5 seconds followed by a cast spin at 1500 rpm for 60 seconds. The wafer was then baked at 205° C. for 60 seconds. Good surface coverage (650 Å) and full via filling (10,000 Å) in vias with a diameter of 0.2 μm and a depth of 1.0 μm were obtained as evidenced by the SEM photograph shown in FIG. 3.
Example 3
[0047] About 30 g of ARC-DUV44-6 (an acrylic anti-reflective coating, available from Brewer Science, Inc.) was blended with 20 g of the solution prepared in Example 1. The mixture was stirred for one hour and filtered through a 0.1 μm end point filter to yield the dual damascene via fill composition. Silicon chips having vias were coated with the composition by different coating processes, depending upon the fill requirements. Good surface coverage (650 Å) and via filling (4700 Å) in vias with a diameter of 0.25 μm and a depth of 1.0 μm were obtained as evidenced by the SEM photograph shown in FIG. 4.
Example 4
[0048] In this example, 1.245 g of SAA-101 polymer (weight-average molecular weight of 2500) and 1.245 g of hydroxypropyl cellulose (Grade SSL obtained from Nisso Chemical, having a molecular weight range of 15,000-30,000) were added to 29.100 g of PGME and 67.900 g of PnP. Next, 495.0 mg of aminoplast crosslinking agent (POWDERLINK® 1174, available from Cytec Industries, Inc.) and 15.00 mg of TSA were added to the mixture, and the resulting solution was mixed for approximately 4 hours at room temperature until homogeneous. The solution was then ion exchanged by tumbling with 5 weight % PGME-washed Dowex 650C beads. The beads were removed by straining the solution through 2 layers of plastic mesh followed by filtering through a 0.1 μm end point.
[0049] The composition was spin-coated onto a quartered silicon wafer containing via holes which were 0.20×0.22 μm in diameter and 1 μm in depth. A dynamic dispense was utilized at 500 rpm for 5 seconds followed by a spread spin of 700 rpm for 25 seconds and then a cast spin at 1800 rpm for 30 seconds (20,000 rpm acceleration rates). SEM photographs of the respective cross-sections of the wafers are shown in FIGS. 5 and 6.
Example 5
[0050] In this example, 1.233 g of SAA-101 polymer (weight-average molecular weight of 2,500) and 1.233 g of polyacrylic acid (having a molecular weight of 2,000) were added to 29.096 g of PGME and 67.886 g of PnP. Next, 493.1 mg of aminoplast crosslinking agent (POWDERLINK® 1174), 9.24 mg of TSA, and 49.3 mg of 4,4′-sulfonyldiphenol were added to the mixture, and the resulting solution was mixed for approximately 2 hours at room temperature until homogeneous. The solution was then ion exchanged by tumbling with 5 weight % PGME-washed Dowex 650C beads. The beads were removed by straining the exchange solution through 2 layers of plastic mesh followed by filtering through a 0.1 μm end point.
[0051] The composition was spin-coated onto a quartered silicon wafer containing via holes which were 0.20×0.22 μm in diameter and 1 μm in depth. A dynamic dispense was utilized at 500 rpm for 5 seconds followed by a spread spin of 700 rpm for 25 seconds and then a cast spin at 1800 rpm for 30 seconds (20,000 rpm acceleration rates). FIGS. 7 and 8 show SEM photographs of cross-sections of these wafers.
Example 6
Anti-Reflective Coating—Hydroxypropyl Cellulose
[0052] 1. Preparation of Mother Liquor
[0053] A 500 mL three-necked flask equipped with a condenser and magnetic stirring bar was charged with 15.0 g of hydroxypropyl cellulose (Grade SSL, obtained from Nisso Chemical), 15.0 g. of poly(styrene/allyl alcohol) (SAA-101, from Lyondell Chemical), and 270.0 g of PnP. The mixture was stirred at 69.5-100° C. for 39 hours to homogeneity.
[0054] 2. Preparation of Anti-Reflective Coating
[0055] About 75 g of the mother liquor prepared in Part 1 of this example, 218.1 g of PnP, 3.78 g of POWDERLINK® 1174, 157 mg of TSA, and 472 mg of 4,4′-sulfonyldiphenol were stirred under ambient conditions to form a solution. The solution was then tumbled with 14.9 g of PGME-washed 650C deionization beads for 4 hours followed by filtering.
[0056] 3. Properties of Anti-Reflective Coating
[0057] The anti-reflective coating prepared in Part 2 of this example was applied to silicon and quartz wafers by spin-coating at 2500 rpm for 60 seconds followed by curing at 205° C. for 60 seconds with hotplate vacuum. The composition had good coating quality. The film thickness was 848 Å, and the optical density at 193 nm was 11.65/μm. The resistance of the film to solvents was determined by puddling a solvent (ethyl lactate) onto the film for 5-10 seconds, followed by spin-drying at 5000 rpm for 30 seconds to remove the solvent. The film was then baked on a hotplate at 100° C. for 30 seconds. The film thickness was measured at multiple points on the wafer using ellipsometry. The amount of stripping was determined to be the difference between the initial and final average film thickness. There was only 0.02% ethyl lactate stripping of this film.
[0058] The composition also had good spin-bowl compatibility. That is, the room temperature-dried anti-reflective coating readily re-dissolved in commonly encountered solvents at room temperature. The etch selectivity to 193 nm resist (PAR 710, Sumitomo Chemical Co.) using HBr/O 2 (60/40) as the etch gas was 1.2.
[0059] A 193 nm photoresist (PAR 710) was applied over 853 Å of the cured anti-reflective layer and soft baked at 130° C. for 60 seconds. Exposures were carried out with an ASML PAS5500/950 scanner (NA=0.63; Sigma=0.75) at exposure energies of 8.3 mJ/cm 2 . A post-exposure bake was carried out at 130° C. for 60 seconds. The photoresist was then developed with OPD262 developer (obtained from ARCH Semiconductor Chemicals) for 60 seconds.
[0060] The SEM photographs (FIG. 9) showed that at an exposure dose of 8.3 mJ/cm 2 the sample had good 0.13 μm dense L/S (line/space) patterns with minimal footing or undercut. Depth-of-focus (DOF) was about 0.4 μm.
Example 7
Anti-Reflective Coating—Cellulose Acetate Hydrogen Phthalate
[0061] 1. Preparation of Mother Liquor
[0062] About 16.0 g of cellulose acetate hydrogen phthalate (CAHP, obtained from Aldrich, product number 32,807-3), 8.62 g of poly(styrene/allyl alcohol) (SAA-101), and 221.5 g of PGMEA in a Nalgene bottle were tumbled on a wheel or sometimes magnetically stirred for 3 days at ambient conditions and then heated with magnetic stirring to 100° C. to give a solution containing only traces of insolubles.
[0063] 2. Preparation of Anti-Reflective Coating
[0064] About 75.0 g of the mother liquor prepared in Part 1 of this example, 126.1 g of PnP, 56.1 g of PGMEA, 2.49 g of POWDERLINK® 1174, 103.5 mg of TSA, and 310 mg of 4,4′-sulfonyldiphenol were stirred under ambient conditions to homogeneity. The solution was then tumbled with 13.0 g of PGME-washed 650C deionization beads for 4 hours at ambient conditions to effect deionization. The beads were removed by straining through a plastic mesh, and the anti-reflective coating was then filtered through a 0.2 μm end point filter.
[0065] 3. Properties of Anti-Reflective Coating
[0066] The anti-reflective coating prepared in Part 2 of this example was applied to silicon and quartz wafers by spin-coating at 2500 rpm for 60 seconds followed by curing at 205° C. for 60 seconds with hotplate vacuum. The film thickness was 967 A, and the optical density was 13.2/μm at 193 nm. There was no ethyl lactate stripping of this film, nor was there any hotplate smoking during the bake step. The anti-reflective coating had good spin-bowl compatibility, and the etch selectivity to resist (PAR 101) using HBr/O 2 (60/40) as the etch gas was 1.1.
[0067] A 193 nm photoresist (PAR 710) was applied to the cured anti-reflective layer and soft baked at 130° C. for 60 seconds. Exposures were carried out with an ASML PAS5500/950 scanner (NA=0.63; Sigma=0.75) at exposure energies of 10.1 mJ/cm 2 . A post-exposure bake was carried out at 130° C. for 60 seconds. The photoresist was then developed with OPD262 developer (obtained from ARCH Semiconductor Chemicals) for 60 seconds. Very good 0.13 μm dense L/S patterns were obtained, with about 0.5%m satisfactory DOF. FIG. 10 shows the SEM photographs of this sample.
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New anti-reflective or fill compositions having improved flow properties are provided. The compositions comprise a styrene-allyl alcohol polymer and preferably at least one other polymer (e.g., cellulosic polymers) in addition to the styrene-allyl alcohol polymer. The inventive compositions can be used to protect contact or via holes from degradation during subsequent etching in the dual damascene process. The inventive compositions can also be applied to substrates (e.g., silicon wafers) to form anti-reflective coating layers having high etch rates which minimize or prevent reflection during subsequent photoresist exposure and developing.
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BACKGROUND OF THE INVENTION
[0001] The present invention concerns an electromagnetic actuator device.
[0002] In such devices a coil unit (typically cylindrical in cross-section) is provided on a stationary yoke unit such that it encloses a first yoke section of the yoke unit and when energised introduces a magnetic flux into the yoke unit. This coil magnetic flux then interacts across a (working) air gap with the armature elements, which in turn execute the desired actuator movement, i.e. a positioning movement for an output-side positioning partner. Here it is on the one hand presupposed to be a generic feature, in the manner of a laterally outwardly mounted coil, to provide the coil unit with the related first yoke section spaced apart from the second yoke section forming the air gap, i.e. to provide the air gap completely outside the first yoke section. While this material originates from the applicant's internal, unpublished prior art, it is on the other hand, in turn a generic feature, presupposed to be of known art, that the coil unit at least partially, i.e. in some sections, encloses the (working) air gap (and in this respect also interacts directly with the armature agents); this corresponds to the functional operation of typical electromagnetic actuators provided axially along the linear direction of movement of the armature.
[0003] Both generic principles have certain advantages in each case; thus, for example, the approach first cited enables by means of the activation (energisation) of the coil unit a specific influence of the flux in the magnetic flux circuit formed by the yoke unit, typically having a plurality of arms. In contrast it can here be established as potentially disadvantageous that the coil efficiency of the coil unit (as a result of the occurrence of undesirable stray fields) is non-optimal, moreover, concepts such as the outwardly mounted coil have the problem of possible transverse forces acting on the armature unit as a result of the coil magnetic flux, i.e. forces (or force components) which not (only) extend along the linear armature direction of movement, but in addition cause a tendency to tilt, and in this respect cause wear; in particular these reduce the suitability of such devices for low wear continuous operation.
[0004] In contrast the generic principle of the armature unit enclosed or covered by the coil unit is less affected by such transverse forces, however, for example, the design-related options for introducing additional magnetic flux into the armature unit (via the working air gap) are limited and are primarily determined by the coil dimensions. As a result disadvantages occur in turn with regard to the utilisation of and/or adaptation to build spaces that are available, possible thermal or winding losses or similar disadvantages. In addition, for example, when utilising such an electromagnetic actuator device for purposes of valve control, the enclosure of the armature unit, in this respect operating effectively on the valve, by means of the coil unit offers the problem of limited supply and removal options for a particular fluid that is to be influenced by the valve.
[0005] The object of the present invention is therefore to improve an electromagnetic actuator device with regard to rendering the magnetic flux in the stationary yoke unit more flexible, in particular with regard to creating the possibility of adapting such an electromagnetic actuator device (potentially at the same time as optimising its efficiency) to build space limitations and/or of minimising possible wear.
SUMMARY OF THE INVENTION
[0006] The object is achieved by the electromagnetic actuator device of the present invention wherein, in a first aspect of the invention, permanent magnet agents are magnetically connected in parallel to a coil unit such that an (additional) permanent magnetic flux of the permanent magnetic agents can occur via the first yoke section (on the coil unit), in this respect, at least with the coil unit deactivated, a magnetic short-circuit of the permanent magnetic agents occurs. At the same time it is inventively established that a coil magnetic flux of the coil unit flowing across the (preferably single) air gap magnetically parallel and/or in the same direction is superposed on a permanent magnetic flux of the permanent magnetic agents flowing across the air gap; in this respect it is achieved that at least with the energisation of the coil unit the permanent magnetic flux (or at least a component of the same) flows across the air gap such that in the case of such an activation of the coil unit by means of energisation an at least partial magnetic flux relocation of the permanent magnetic flux from the first yoke section (namely the continuous section of the coil unit that is free of air gaps), flows into the second yoke section interacting with the (working) air gap and accordingly this flux shift or flux displacement leads to an influence on the positioning or switching characteristic of the armature unit interacting with the air gap.
[0007] In other words the present invention, in accordance with the first aspect of the invention in accordance with the main claim, advantageously causes that as a reaction to the energisation of the coil unit the coil magnetic flux thereby generated causes the shift or displacement of the permanent magnetic flux of the permanent magnetic agents. In this manner the coil magnetic flux generated by the coil assumes the character of a field opposing that of the permanent magnet, and can in this respect influence the permanent magnetic flux efficiently, potentially (relative to the coil magnetic flux) in a manner increasing the flux, in the simplest case with regard to the switching on or off of a particular arm.
[0008] This inventive action appears to be of particular interest and practically beneficial if, in an alternative to the permanent energisation of the coil unit this activation takes place purely in the form of a pulse, as is foreseen as per further developments, and then, as a reaction to this pulsed form of activation (and an already thereby evoked relocation or reaction of the movement units of the actuator device involved), a mono-stable or bi-stable switching characteristic is achieved. This is the case, for example, if as a reaction to the pulsed form of energisation of the coil unit an armature movement thereby caused (which then in a suitable manner displaces at least a part of the permanent magnetic flux into the air gap and in this respect increases the armature force) leads to a closure of the air gap. This can advantageously cause that in this switching state the permanent magnet flux (for example, by virtue of a lower magnetic resistance of the second yoke section with a reduced or closed air gap) primarily flows through this second yoke section, in this respect this armature position closing the air gap is then stably held by the action of the permanent magnetic agents, without, for example, the need for any further renewed energisation of the coil unit. Thus a bistable device is achieved.
[0009] If in turn in the further development of the invention a restoring device, for example, in the form of a compression spring or a restoring spring, is assigned to the armature agents, against which the armature operates in the above-described manner, by means of a suitable setting, for example, of the spring force, the movement and/or switching behaviour of the armature unit can be further influenced, for example can be configured as a monostable variant, wherein, after completion of the energisation pulse, a (spring-) restorative force of sufficiently large dimensions brings the armature unit back into its initial position against the force action of the permanent magnetic flux.
[0010] Again additionally or alternatively in a manner of otherwise known art, through the adjustment of an effective separation distance for the armature unit, i.e. the air gap (e.g. by the deployment of suitable non-magnetic non-stick or non-adhesive disks on the second yoke section) can the detainment and movement characteristics be influenced, in that, for example, such a non-magnetic separation distance retainer increases the air gap between armature and yoke.
[0011] In all these forms of implementation it is both covered by the invention and possible within the context of suitable designs, to design the permanent magnetic agents in the form of an individual magnetic element (preferably of elongated design and axially magnetised along the direction of extension), as is also the deployment of a multiplicity of such permanent magnet elements, which are then provided at suitable positions, in particular opposing with regard to the air gap and/or the coil unit; in the same way the present invention covers the provision of the armature agents in the form of a multiplicity of suitably guided, i.e. mounted armature units, also independent of one another, wherein then the inventive second yoke section correspondingly implements a plurality of regions, i.e. sections, of the yoke unit.
[0012] Also provision is made, again in terms of adaptation to particular fields of deployment, in an advantageous and sensible, but not limiting, manner, to provide an axial direction of extension (again corresponding to a magnetisation direction) of the permanent magnetic agents approximately on an axis parallel to a linear direction of movement of the (at least one) armature unit, again as per further developments to configure a direction of extension of the (surrounded by the coil unit) first yoke section parallel to these axes (or to one of these), again as per further developments and advantageously to establish the coil unit with a coil axis or a coil longitudinal axis such that an armature direction of movement takes place parallel to the coil longitudinal axis. All of these further developments can also be deployed independently of one another within the context of the invention with advantage.
[0013] In particular against a background of the object, as set, of the actuation of a multiplicity of armature units by means of a common coil unit, provision is made as per further developments and preferably to provide the respective related second yoke sections of these armature units suitably adjacent and/or distributed around the periphery, with regard to the coil unit, so as to be able to implement geometrical or spatial advantages in this respect.
[0014] This flexibility applies additionally or alternatively as per further developments also for the possibility of positioning the inventive permanent magnetic agents in the form of a multiplicity of individual permanent magnet elements distributed and/or positioned at predetermined positions relative to the coil unit and/or to at least one armature unit (i.e. the respectively related armature sections). Thus it is possible, additionally and advantageously, in addition to an (installation) space optimisation, in particular also to optimise the above-described transverse force problems on the armature agents, in that particular (operational) magnetic flux components of the coil unit on the one hand as well as the permanent magnetic flux components of the permanent magnetic elements on the other hand are thus brought into equilibrium in terms of flux, such that the disadvantageous transverse force effects on the armature agents (of one individual armature unit, also, potentially as per further developments, a multiplicity of armature units) are minimised.
[0015] It is particularly advantageous in the context of such preferred further developments of the invention to connect the respective flux-generating components, i.e. components reacting to the magnetic flux (coil unit with first yoke section, armature agents with second yoke section and air gap, permanent magnetic agents) by means of flux-conducting elements, further preferred in each case at both ends with the formation of a magnetic parallel connection, i.e. a flux-conducting arrangement of at least two flux-conducting circuits, wherein it has been shown in terms of design and magnetic characteristics to be particularly preferable to provide such flux-conducting elements (which in particular can also be implemented as sections of the e.g. one-piece yoke unit, alternatively in modular form assembled from predetermined modules) such that they run at right-angles to a (linear) direction of movement of the at least one armature unit, i.e. at right-angles to a magnetisation direction of the at least one permanent magnet unit, or at right-angles to a longitudinal direction of the first yoke section (and thus at right-angles to a direction of extension of the coil unit). Such a flux-conducting element, which further preferably can be provided at both ends of the cited magnetic components, can suitably be configured as a flat module (for example as platelets), and/or can use a design, which possesses at least one flat side, so that beneficially, for example, otherwise of known art magnetic flux-conducting sheets (which moreover in terms of production technology can beneficially be stamped out and are thus suitable for large scale production) can be used suitably stacked for purposes of implementation of the various sections of the yoke unit.
[0016] In the further optimisation of the present invention, in particular in the case of a multiplicity of (individual) magnet elements provided and individual coils of the coil device, it is, for example, possible, for purposes of implementation of the above-described invention principle, to arrange the permanent magnet unit and coil unit relative to one another in pairs, so that, with respect to one such pair, in each case the permanent magnetic flux can flow through the first yoke section of the related coil unit, while an energisation of the respective coil units inventively displaces the permanent magnetic, flux for purposes of influencing the armature movement, into the at least one second yoke section for one or a plurality of armature units. In the context of optimisations for a particular arrangement geometry (i.e. as a function of particular installation conditions) such pairs of coil units/permanent magnet units would then again as per further developments be suitably aligned relative to the armature agents, for example, suitably in the shape of a curve and/or circle about the armature centre, in turn suitably and further preferably magnetically coupled via flux-conducting elements engaging at one or both ends.
[0017] In accordance with a second aspect of the invention, the permanent magnetic agents are used so as to influence the magnetic flux and positioning characteristics of an electromagnetic actuator device, in which the coil unit at least partially encloses the working air gap and/or the armature agents, that is to say, no laterally outwardly mounted arrangement is present as in the first aspect of the invention.
[0018] Nevertheless here too a flux-conducting section of the yoke unit of the coil unit is provided outside of the first yoke section, for purposes of forming at least one magnetic flux path that is free of air gaps. In the context of this aspect of the invention permanent magnetic agents are magnetically connected in parallel with the coil unit, such that in a de-energised state of the coil unit a permanent magnetic flux of the permanent magnetic agents is guided via this flux-conducting section, so that in this respect the flux-conducting section acts as a magnetic short-circuit for the permanent magnetic agents, if the coil unit is not activated.
[0019] Following the above overall concepts of the invention, an activation of the coil unit by means of energisation causes, however, at least a partial relocation of the magnetic flux, in particular a displacement of the permanent magnetic flux from the flux-conducting section of the yoke unit in the first yoke section (and thus across the air gap) with the consequence that by this means the armature force is then influenced. In this respect this aspect of the invention also thus enables advantageously that as a reaction to an activation of the coil unit a permanent magnetic flux, which is additionally coupled into the system in a flux-conducting manner, is specifically influenced, in particular is switched on and off with regard to the first yoke section and the armature unit.
[0020] In this aspect of the invention the possibilities discussed in the introduction also apply, of configuring geometrically the respective magnetically effective sections into one or more parts, wherein for example a preferred form of implementation of the invention envisages that the inventive flux-conducting section (for the guidance of the permanent magnetic flux in the de-energised state of the coil unit) forms at least two flux conducting arms running magnetically parallel to one another, which can, for example, be preferably provided adjacent to the coil device on the cover side, further preferably facing one another with regard to the coil device.
[0021] In a particularly preferred manner the flux-conducting section is designed moreover, for example, as a section or region of a flux-conducting housing (in particular a housing shell) of the actuator device, wherein this housing shell encloses the coil unit on the cover side as per further developments and the permanent magnetic agents are provided either on or in the housing shell to achieve the described flux guidance; it is particularly advantageous if for example a direction of magnetisation of the permanent magnetic agents runs parallel to a direction of movement of the armature agents, so that in this case then, with a typical sleeve or cylinder shaped housing, a direction of extension and magnetisation direction of the permanent magnetic agents also runs parallel to an axial direction of the sleeve or cylinder.
[0022] Additionally or alternatively it is possible that the permanent magnetic agents, again as per further developments, are externally placed in the described relative alignment on a (closed) housing section of the housing shell, so that in this respect the lateral (short-circuit) magnetic flux can again flow in the de-energised state of the coil unit; an alternative form of implementation could envisage that the (elongated) permanent magnetic agents are provided in a suitably dimensioned recess (slot or gap) of the housing shell, at its ends coupled in a flux-conducting manner.
[0023] The possibilities provided as per further developments, to connect the permanent magnetic agents and the first yoke section (with the coil unit) via flux-conducting regions, i.e. flux-conducting elements, running suitably at right-angles to the respective direction of extensions, also apply for this aspect of the invention, wherein these flux-conducting elements again can be implemented in a manner suitable for large-scale production as a component of the yoke unit, flat as per further developments and/or with the aid of individual sheets or sheet stacks.
[0024] As a result there is generated by means of the present invention of two aspects of invention a surprisingly effective, high quality flexible system of coil unit, armature agents and permanent magnet unit, which combines the possibility of an optimised mechanical arrangement and/or build space utilisation with a magnetic flux optimisation for purposes of module dimensioning, loss minimisation (with regard to the coil unit, for example) and the prevention of undesirable possible transverse forces with regard to the armature unit, so that in this respect wear optimisation is also enabled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Further advantages, features, and details of the invention ensue from the following description of preferred examples of embodiment and also with the aid of the drawings; these show in:
[0026] FIG. 1 : a schematic diagram to clarify the essential functional components of the first aspect of the invention and their interaction with one another;
[0027] FIG. 2 to FIG. 5 : the interaction of the functional components in accordance with FIG. 1 in energised operation for purposes of achieving bistability;
[0028] FIGS. 6 , 7 : a variant for the implementation of FIG. 1 with a deviation in the guidance of the permanent magnetic flux;
[0029] FIG. 8 to FIG. 12 : further variants of the first aspect of the invention with a multiplicity of armature units, i.e. a multiplicity of individual permanent magnet elements in the framework of a parallel arrangement connected by flux-conducting agents;
[0030] FIG. 13 to FIG. 15 : a concrete implementation of the first aspect of the invention shown in perspective and as a mechanical design with an arrangement of a coil unit and a pair of permanent magnets, which on both sides are connected by flat flux-conducting agents;
[0031] FIGS. 16 , 17 : a schematic topographical presentation of a design variant of FIGS. 13 to 15 with two coil-permanent magnet pairs arranged in pairs, on both sides adjacent to the armature unit;
[0032] FIG. 18 to FIG. 21 : further arrangements with coil-permanent magnet pairs in a circular-peripheral assignment to a central armature unit;
[0033] FIGS. 22 , 23 : asymmetric variants in the assignment of permanent magnets and coil in an analogous manner to the configurations of FIGS. 18 to 21 ;
[0034] FIGS. 24 , 25 : representations of principles to clarify the second aspect of the invention with the coil device enclosing the armature unit, i.e. the air gap;
[0035] FIG. 26 to FIG. 31 : various design variants of the assignment of permanent magnetic agents to a housing cover (as a flux-conducting section) and therein with magnetic fluxes generated with a de-energised or an energised coil.
DETAILED DESCRIPTION
[0036] With the aid of FIGS. 1 to 5 the general design and magnetic principles are described together with a possible (e.g. bistable) operating mode of the present invention. Thus the device, shown schematically in FIG. 1 and shown analogously in FIG. 2 with the functional components, has an electromagnetic actuator device, which has armature agents 10 , moveably guided, moveable axially (i.e. directed upwards in the respective plane of the figure) relative to a yoke section 12 (the second yoke section in the context of the invention). Between the armature agents 10 and the yoke section 12 a variable (preferably single) air gap 14 is formed, corresponding to a separation distance between armature and yoke, across which, as a working air gap, a magnetic flux is guided, so as in this respect to undertake an application of force onto the armature unit 10 for purposes of driving the same.
[0037] The yoke section 12 is a component of a (stationary, i.e. held or secured such that it cannot move) yoke unit, essentially consisting of a yoke section 18 (the first yoke section in the context of the invention, also designated as the coil core) assigned to a coil 16 provided in an adjacent arm. Furthermore a permanent magnet unit 20 is held in an opposite arm of the yoke unit 18 , wherein flux-conducting sections 22 , 24 , in the example represented on both sides of the permanent magnet unit 20 and also on both sides of the coil unit 16 (i.e. of the related yoke section) connect the flux-conducting components, in the example of embodiment represented create approximately centrally a magnetic flux connection to the yoke section 12 and, as indicated in FIGS. 2 to 5 , provide a gap 26 to allow the armature unit 10 to pass through (and in this respect for purposes of introducing a magnetic flux into the armature unit for the air gap 14 , i.e. the yoke section 10 ). In this configuration of the stationary yoke unit, the respective longitudinal axes, i.e. the axes of movement of the participating components are here aligned adjacent and parallel to one another for purposes of achieving a compact arrangement. A coil longitudinal axis, defined by the direction of extension of the yoke section 18 , runs in parallel to the direction of extension (and direction of magnetisation) of the elongated design of the permanent magnet element 20 , and in parallel to the direction of extension and direction of movement of the armature unit 10 .
[0038] FIG. 3 illustrates a flux path in the de-energised state of the coil unit 16 in the arrangement just schematically shown in FIG. 1 and FIG. 2 , wherein the cluster of arrows 28 just illustrates the (permanent) magnetic flux caused by the permanent magnet unit 20 . Since in the arrangement of FIGS. 1 to 4 the air gap 14 is open, and in this respect provides an increased magnetic flux resistance compared with the yoke section 18 , practically the whole permanent magnetic flux in this state of armature position runs, as illustrated in accordance with the arrow arrangement 28 in FIG. 3 , via the yoke section 18 , so that in this respect a magnetic short-circuit of the permanent magnet unit 20 occurs via the first yoke section 18 (core section) of the coil unit 16 .
[0039] If then, as shown in FIG. 4 , the coil 16 is energised, a coil magnetic field occurs, which causes the coil magnetic flux illustrated by the cluster of arrows 30 . The polarity of the coil unit is such that a magnetic flux flowing in the yoke section 18 is directed against the direction of the permanent magnet (in section 18 ), so that by the action of the coil magnetic flux 30 not only is the (further) entry of the permanent magnetic flux 28 into the yoke section 18 prevented, but rather this permanent magnetic flux (also illustrated in FIG. 4 with the reference symbol 28 as a cluster of arrows) is displaced into the armature unit 10 , i.e. the second yoke section 12 . Since, moreover, the permanent magnet unit 20 opposes the coil magnetic flux 30 with a greater resistance than does the sequence of armature unit 10 , air gap 14 and yoke section (stator) 12 , the coil magnetic flux 30 , in this respect for purposes of closing this magnetic flux circuit, is displaced into this central arm.
[0040] As a result, as illustrated in FIG. 4 in terms of the magnetic fluxes directed parallel to one another through the armature unit and across the air gap, both the coil magnetic flux 30 and also the permanent magnet flux 28 mutually run effectively across the working air gap, summating their action accordingly and thus cause, by the energisation of the coil unit 16 , to ensure that a common, superposed and summated magnetic flux acts on the armature unit and drives the latter (so as to close the air gap 14 ).
[0041] The result of this drive process is shown in the presentation in FIG. 5 , with a coil unit that is again deactivated (so that, as the above description of the example of embodiment of FIGS. 2 to 5 indicates, a temporary, e.g. a pulse-form energisation of the coil unit 16 is sufficient to move the armature unit 10 that is in a first, disconnected, i.e. open state, into a second contact state that closes the air gap ( FIG. 5 ). Moreover it can be discerned that the permanent magnetic flux 28 now flowing through the sequence of armature unit 10 —yoke section 12 seeks to provide for a stable contact position of the armature unit 10 on the yoke section 12 (while practically no permanent magnetic flux, or just a negligible component of the permanent magnetic flux, flows via the yoke section 18 assigned to the coil unit 16 , since the now closed armature position provides a lower magnetic flux resistance).
[0042] In this manner a bistable mode of operation of the electromagnetic actuator device is demonstrated, which is stable with zero current in each of the armature positions shown. At the same time if it were necessary in the case of the configuration shown to bring about again a reset of the armature unit 10 from the lower contact position of FIG. 5 into the open position ( FIGS. 2 to 4 ) this can, for example take place via the introduction of an external force (not shown in any detail in the figures), as is of known art, for example, in terms of a valve lift adjustment of cam shafts or similar, additionally or alternatively via the provision of a spring or similar energy store, against which, for example, the armature unit 10 operates, and which then, with the cessation of the energisation of the coil 16 , guides the armature unit back into an upper position that opens the air gap.
[0043] Also it would be possible, for example, for purposes of reducing a possible reset force of the armature, to energise the coil unit 16 temporarily in reverse in a suitable manner.
[0044] The example of embodiment of FIGS. 6 , 7 reverses the arrangement of the arm adjacent to the permanent magnetic agents; here the (first) yoke section 18 assigned to the coil unit for purposes of forming a magnetic flux circuit (in the manner of a short-circuit) is provided axially adjacent to the permanent magnet unit 20 ; the axially aligned with one another and moveable arrangement comprising the stationary yoke section 12 and axially moveable armature unit 10 is then adjacent to the yoke section 18 .
[0045] As the permanent magnetic flux illustration of FIG. 6 shows (with the coil unit deactivated) a permanent magnetic flux 34 flows through the yoke section 18 , in this respect leaving the arm formed from armature and yoke section 12 together with the air gap 14 outside the flux path. An activation of the coil unit 16 then causes, in an analogous manner to the above-described example of embodiment, the addition or superposition of permanent and coil magnetic flux in the air gap arm to move the armature unit so as to close the air gap, so that, after a renewed deactivation of the coil unit, the bistable state of FIG. 7 ensues. Since, however, by virtue of the closed air gap the arm formed from the yoke section 12 and armature unit 10 has a reduced magnetic resistance compared with the open air gap of FIG. 6 , a permanent magnetic flux component 35 also flows through this arm, in this respect subdividing the permanent magnetic flux of the permanent magnet 20 . Nevertheless a relatively larger, more significant flux component flows, now as before, through the yoke section 18 .
[0046] The result is that in comparison to the situation of FIG. 5 in the first described example of embodiment, lower restoring forces are required so as to release the armature unit 10 from the position of FIG. 7 of the related yoke section 12 . If then in addition another distance element, or anti-stick element, of non-magnetic material, otherwise of known art, is used on the end face, i.e. contact side of the yoke element 12 in the direction onto the armature unit 10 , as a result of thereby achieved effective increase of the air gap (in the contact state) the holding force ( FIG. 7 ) can be further reduced, so that for particular applications suitable configuration and design options are available.
[0047] The example of embodiment of FIGS. 8 to 10 illustrates a variant of the invention, in which a permanent magnet unit is operated together with a multiplicity of armature units interacting across a respective working air gap with a stationary yoke section. Here, with respect to the armature units 40 and 42 , provided on both sides of the yoke unit 18 , i.e. of the related coil unit 16 , with related air gaps 44 and 46 and stationary yoke sections 48 and 50 , the magnetic flux paths thus formed are configured such that, for example, as a result of a shorter gap separation distance 46 compared with the gap separation distance 44 , the arm 42 , 46 , 50 has a lower magnetic resistance compared with the arm 40 , 44 , 48 , so that while it is true that in the deactivated state of FIG. 8 , in which just the permanent magnet flux (arrow bundle 52 ) passes through the yoke section 18 , both armature arms remain without flux, when the coil 16 is energised in an analogous manner to the earlier described effect, the displacement and flux concentration of both the permanent magnetic flux 52 and also the coil magnetic flux 54 caused by the coil activation primarily takes place over the right-hand side armature arm, and therefore over the shorter air gap 46 . This leads to the fact that it is the right-hand side air gap 46 that is firstly closed by the force correspondingly acting on the armature unit 42 .
[0048] In the unit, by appropriate dimensioning of the effective flux cross-section of the arm formed from the units 42 , 50 , the latter by the increase of the magnetic flux into a magnetic saturation, there then takes place in turn, as shown in FIG. 10 , a (partial) displacement of the flux into the arm formed from the armature unit 40 , air gap 44 and yoke unit 48 , as shown by the bundle of arrows 56 ; this flux is supplied essentially from components of the coil magnetic flux which, by means of the described saturation effect in the arm 42 , 50 only runs to a limited extent via this arm and is then primarily displaced into the left-hand side arm 40 , 48 . The end result is that the air gap 44 is also closed.
[0049] Thus the example of embodiment of FIGS. 8 to 10 demonstrates that by a suitable design of respective flux-conducting circuits, i.e. flux-conducting arms, for example by means of suitable cross-sectional dimensioning of the flux-conducting yoke sections and/or configuration of the air gaps, a drive sequence can be established, i.e. achieved, for the respective armature units in the described example of embodiment, for example, such that the armature unit 42 moves firstly, and only subsequently does the armature unit 40 move.
[0050] The example of embodiment of FIGS. 11 , 12 supplements the variant of FIGS. 8 to 10 with a second permanent magnet unit 21 , which in accordance with the principles as represented is provided at the other end opposite the permanent magnet unit 21 ; the second permanent magnet unit 21 firstly generates an independent permanent magnetic flux 58 which, cf. FIGS. 10 and 11 , is discernible as a reaction to the closure of the air gap 46 (i.e. saturation taking place in the related flux-conducting components 42 , 50 ); this permanent magnetic flux 58 together with a component of the coil magnetic flux 56 (in an analogous manner to FIG. 10 ) is superposed on the working air gap 44 , causing in this respect in the context of the inventive principle, a switched flux amplification and thus an influential effect.
[0051] FIGS. 13 to 15 describe a further example of embodiment of the present invention, in contrast to the above-described forms of implementation, which were rather schematically represented, these provide a typical example of how the respective flux-conducting components participating in the implementation of the schematically represented functionality can be configured. Thus, for example, the perspective representation shows how the yoke sections 22 , 24 (as sections connecting the ends of the participating components in each case) can be suitably implemented from a stack of transformer sheets, typically stamped or similar, and thus combine the otherwise of known art beneficial vortex flow minimisation effects with advantageous flux conductivity and good suitability for a preferred form of suitable large-scale production.
[0052] The examples of embodiment of FIGS. 13 to 15 illustrate moreover, how by suitable positioning of the coil unit, or of a pair of permanent magnets relative to the movable armature unit, potentially disadvantageous gravitational force components on the armature unit can be reduced (as would otherwise typically be anticipated to be present in laterally outwardly mounted coil-armature combinations, and which can lead to wear, i.e. reduction of service life).
[0053] Thus, for example, the perspective representation of FIGS. 13 to 15 (wherein FIG. 14 illustrates just the permanent magnetic flux, and FIG. 15 illustrates the superposed permanent and coil magnetic fluxes), shows how a permanent magnetic short-circuit flux ( FIG. 14 ) occurs outside the working air gap along the flux-conducting sheet stack 22 , 24 , while as illustrated in FIG. 15 , by means of the introduction of flux on both or all sides in the direction towards the armature unit 10 (which interacts with a stationary yoke section, in the figures shown as concealed, with the formation of the working air gap) shows how a balance, i.e. equalisation, of the force components aligned in the plane of the respective flux-conducting sheet elements 22 and 24 occurs with regard to an axial direction of movement of the armature unit.
[0054] In an analogous manner to the above-described examples of embodiment (for example the representation of principles in FIG. 4 in comparison to FIG. 3 ) in the de-energised state of the coil ( FIG. 14 ) there occurs the permanent magnetic flux through the yoke section 18 assigned to the coil 16 , while in the energised state of the coil ( FIG. 15 ) the coil magnetic field causes a flux displacement, i.e. displacement of the permanent and coil magnetic fields through the working air gap. For purposes of illustrating the principal common features for the above-described examples of embodiment equivalent reference symbols have been introduced into FIGS. 14 and 15 .
[0055] The examples of embodiment in FIGS. 16 to 23 illustrate how by means of an arrangement of (a multiplicity of) respective permanent magnets and with suitably assigned, e.g. in pairs, coil units (together with in each case a yoke section related to a coil for purposes of short-circuiting of the related permanent magnetic fluxes in the de-energised state of the respective coil), numerous configurations and adaptation options for a respective case of embodiment exist and provide for a minimisation of transverse force in practically all coils. Thus, for example, the schematic plan views onto an arrangement in accordance with FIGS. 16 and 17 , in which on both sides of a central armature unit 60 in each case a coil-permanent magnet pair consisting of a permanent magnet rod 62 or 64 and also a related coil unit 66 or 68 , in each case again consisting of a yoke section and related winding, illustrate how in the de-energised form any permanent magnet influence shown in FIG. 16 , by means of a short-circuit over a respective coil-yoke section is held apart from the armature, while in the energised state of the two coil units 66 and 68 shown in FIG. 17 the above-described displacement occurs of the permanent magnet fluxes of the permanent magnet unit 64 or 62 onto the armature unit (i.e. onto the air gap axially aligned with the latter, not shown in the figures).
[0056] Further variants, in an analogous manner to this approach, ensue from the pairs of configurations of FIGS. 18 (de-energised) and 21 (analogous topology, but energised), further variants in the form of the topologies are shown in FIGS. 19 and 20 , only in the de-energised state. Here the solid black circles and squares symbolise respective permanent magnets 70 which, in an analogous manner to the representation of FIGS. 16 , 17 , extend axially in a direction perpendicular to the plane of the figure, while the solid white circles 72 in each case symbolise a yoke section extending parallel to the former to g ether with the coil winding surrounding the latter, with an indication of the respective permanent magnetic fluxes and, in the case of FIG. 21 , in the energised state.
[0057] Here the present invention is limited neither to the arrangements shown, nor to the numbers (2 or 3) of pairs of permanent magnets and coils, rather this classification scheme can be adapted and duplicated or multiplied in any manner, wherein in particular even the number of respective coil units (with related yoke sections) does not have to agree with the number of permanent magnets, as illustrated for example by the variants of FIGS. 22 and 23 . However in the context of preferred examples of embodiment of the invention it is beneficial if the arrangement of the permanent magnets and the coils relative to the armature unit is symmetrical (more preferably if it is radially symmetrical), so that advantages can here be implemented against the background of an intended optimisation of transverse force.
[0058] In the form of embodiment of FIG. 22 it is in this regard sensible if all three magnetic sources (i.e. the pair of permanent magnets 70 and the coil unit 72 ) in the arrangement shown provide an equal magnetic field strength, so as not to allow any transverse forces to act on the armature unit. In the arrangement of FIG. 23 , in which the pair of permanent magnets are arranged opposite one another with regard to the central armature axis, it is just the permanent magnetic flux that must be displaced out of the related coil-yoke section by the energisation of the coil 72 , so as to generate in the present inventive manner an axial force by means of the permanent magnets. Again the transverse force is advantageously minimised by the symmetrical arrangement.
[0059] With the aid of FIGS. 24 to 31 in what follows a further aspect of the invention is described with examples of embodiment; here, in an alternative to the above described first aspect of the invention, the armature-air gap-stator arm is itself covered with a coil, wherein this aspect of the invention, in an interaction with a laterally outwardly mounted permanent magnet unit, increases the coil efficiency in an advantageous manner.
[0060] The appropriate principle together with the magnetic flux paths is shown by the comparison between FIGS. 24 and 25 . Again connected at both sides and both ends by flux-conducting sections 22 and 24 at one end an elongated axially magnetised permanent magnet unit 20 is provided; at the other end and directly adjacent to the coil a yoke section 80 and 82 is provided in each case. Between the yoke sections 80 and 82 (which in the manner to be described in what follows are implemented by means of a suitable housing of the electromagnetic actuator) is provided, covered by a winding 16 , a combination consisting of an armature unit 10 a yoke section 12 acting as a stator, and an air gap 14 provided in between.
[0061] Here in accordance with FIG. 24 in the de-energised state of the coil unit 16 a permanent magnetic flux 84 runs in accordance with the arrows as shown, namely in the centre of gravity through the proximal yoke section 82 and, with a reduced flux component (since further removed and thus with a somewhat higher magnetic resistance) through the distal yoke section 80 .
[0062] The energisation of the coil unit 16 , as shown schematically in FIG. 25 , leads then to a resultant flux path in such a way, that, superposed with the permanent magnetic flux 84 now in the armature arm and displaced via the air gap 14 in addition a coil magnetic flux 86 runs in an additive and superposed manner, so that in the context of the present invention an introduction of force onto the armature unit 10 here takes place in an optimised manner.
[0063] FIGS. 26 to 31 illustrate possible implementations of this principle in the practical execution, wherein FIG. 26 shows a first example of design embodiment in the axially partially sectioned state, FIG. 27 shows the permanent magnetic flux in this arrangement and FIG. 28 shows a resultant magnetic flux path in the case of additional energisation of the coil unit in the design implementation in accordance with FIG. 26 : In this example of embodiment the housing is implemented in the shape of a curve such that an outer lying permanent magnet 20 (of a pair 20 , 21 engaging in both sides) is connected via the flux-conducting sections 22 , 24 to the yoke sections 80 and 82 , which in the example of embodiment represented are implemented via sections of the housing. For purposes of further illustration the reference symbols selected in FIGS. 26 to 31 correspond to those of FIGS. 24 and 25 . It becomes apparent that with energisation of the coil unit ( FIG. 28 ) the permanent magnetic flux 84 (in comparison to FIG. 27 , in which in the de-energised state just a permanent magnetic short-circuit takes place via the housing wall 82 ) is displaced into the sequence of armature unit 10 , air gap 14 and stator-yoke section 12 in which movement is effective.
[0064] As a variant to the form of embodiment in FIGS. 26 to 28 the example of embodiment in FIGS. 29 to 31 shows how the permanent magnet 20 , instead of being superimposed from the exterior via a curved arrangement onto the cylindrical actuator housing, is introduced into a longitudinal slot 90 of this housing, whereby then, for purposes of implementation of the permanent magnetic short-circuit function in the de-energised state ( FIG. 30 ), the permanent magnetic flux runs via the housing sections adjacent to the slot, while in the energised state of the coil unit and in accordance with the representation in FIG. 31 , here again the flux displacement and superposition with the coil magnetic flux takes place.
[0065] All of these examples of embodiment have the advantage (compared with the above-described aspect of the invention) that the coil is covered over its total circumference by a magnetically conducting housing, which accordingly reduces undesirable stray fields. Through the variant of integration of the permanent magnet into the housing as shown, either in the context of a superimposed arrangement arranged from the exterior in accordance with FIG. 26 , alternatively a variant introduced into the housing by means of a slot, it is possible in both cases to maintain the advantage of the closed housing. Here it is sensible to generate a high magnetic flux density in the housing by means of the electromagnets (coil unit with yoke section) so that the electromagnetic field does not only propagate locally on one side of the housing (and then the permanent magnetic flux remains maintained on a housing side) Also the described second aspect of the invention offers the advantage that the housing (or any from the exterior superimposed flux-conducting curve) can be implemented in a relatively thin manner, alone as a result of the displacement of the permanent magnetic flux already a relatively high magnetic flux occurs over the working air gap, so that the total magnetic flux in large parts of the housing can be low and correspondingly enables only low magnetically effective flux cross-sections.
[0066] While moreover this inventive principle can be implemented with just one permanent magnet element (as, for example, in the example of embodiment of FIG. 29 ) it is possible, for example, as in the example of embodiment of FIG. 26 with the permanent magnets sitting on both sides, suitably to provide a plurality of magnets and so again to be able to adapt to the arrangement of application conditions in each case provided.
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An electromagnetic actuator device, comprising a coil unit, which surrounds a first yoke section of a stationary yoke unit and is activated by energizing the coil unit, and armature elements, which are guided so as to be movable relative to the yoke unit and which interact with an output-side actuating partner and are driven in order to perform an actuating movement, the armature elements interact with at least one second yoke section of the yoke unit to form an air gap lying outside of the first yoke section for a magnetic flux produced by the activated coil unit. Permanent magnet elements are connected magnetically parallel to the coil unit in such a way that a permanent-magnet magnetic flux of the permanent magnet elements through the first yoke section can occur, a coil magnetic flux of the coil unit flowing across the air gap is overlaid in a magnetically parallel and/or equally directed manner with a permanent-magnet magnetic flux of the permanent magnet elements flowing across the air gap, and activation of the coil unit by means of energizing causes an at least partial magnetic flux shift, in particular magnetic flux displacement, of the permanent-magnet magnetic flux of the permanent magnet elements from the first yoke section to the second yoke section.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/642,378, filed May 3, 2012 and U.S. Provisional Patent Application No. 61/642,292, filed May 3, 2012 which applications are incorporated herein by reference.
REFERENCE TO COMPUTER PROGRAM LISTING APPENDIX
[0002] The present application includes the following computer program listing appendix. The computer program listing appendix is expressly incorporated herein by reference in its entirety. The appendix contains an ASCII text file of the computer program as follows:
[0000]
AdminWindow.txt
15.6
KB
Created May 3, 2013
AdminWindow-2.txt
8.93
KB
Created May 3, 2013
app.txt
.5
KB
Created May 3, 2013
appmanifest.txt
2.44
KB
Created May 3, 2013
Browser.txt
2.63
KB
Created May 3, 2013
Browser-2.txt
2.79
KB
Created May 3, 2013
FileIO.txt
1.29
KB
Created May 3, 2013
HtmlReport.txt
108
KB
Created May 3, 2013
IniBS.txt
1.62
KB
Created May 3, 2013
LogInWindow.txt
2.78
KB
Created May 3, 2013
LogInWindow-2.txt
3.38
KB
Created May 3, 2013
MainWindow.txt
70.7
KB
Created May 3, 2013
MainWindow-2.txt
26.9
KB
Created May 3, 2013
mod1.txt
294
KB
Created May 3, 2013
mod3.txt
175
KB
Created May 3, 2013
mod4.txt
67.5
KB
Created May 3, 2013
PatientsWindow.txt
13.0
KB
Created May 3, 2013
colortest.txt
38.5
KB
Created May 3, 2013
form1.txt
24.4
KB
Created May 3, 2013
FIELD OF THE INVENTION
[0003] The present method and apparatus relate to eye tests for hereditary and acquired color vision loss and may be used for the early detection, progress, treatment and monitoring of eye conditions, optic neuritis, traumatic brain injury, systemic and neurological diseases including Glaucoma, Retinopathy, Age-Related Macular Degeneration, Multiple Sclerosis, potentially Alzheimer's Disease and Parkinson's Disease, as well as Retinal Toxicity due to high-risk medications. Particularly, the systems and methods disclosed herein use a Cone Contrast Test (CCT) to identify hereditary color deficiency and acquired color vision loss associated with early disease/damage/toxicity to (a) alert for early disease/damage/toxicity in an effort to (i) provide opportunity for treatment, and (ii) prevent permanent eye damage, and (b) monitor progress and treatment of such disease/damage/toxicity.
BACKGROUND OF THE INVENTION
[0004] The human eye sees color as a result of three types of receptors, called cones, listed in the chart below. A range of wavelengths of light stimulates each of these receptor types to varying degrees. Yellowish-green light, for example, stimulates both L and M cones equally strongly, but only stimulates S-cones weakly; red light stimulates L cones much more than M cones, and S cones hardly at all; blue-green light stimulates M cones more than L cones, and S cones a bit more strongly; and blue light stimulates S cones more strongly than red or green light, but L and M cones more weakly. The brain combines the information from each type of receptor to give rise to different perceptions (i.e., colors) of different wavelengths of light.
[0000]
Cone type
Name
Range
Peak wavelength
S
B
400-500 nm
420-440 nm
M
F
450-630 nm
534-555 nm
L
P
500-700 nm
564-580 nm
[0005] Test procedures such as optical computed tomography (OCT), visual field analyzers, etc., are used primarily to screen and diagnose specific eye disease. OCTs and visual field analyzers are tests generally used once the patient is symptomatic, well after permanent eye damage has occurred.
[0006] A test, called the Cone Contrast Test (CCT), is used to determine deficiencies of these cones in an individual's eye. The CCT is explained in greater detail in the published articles titled “Rapid Quantification of Color Vision: The Cone Contrast Test” by Rabin et al. published in Investigative Ophthalmology & Visual Science , February 2011, Vol. 52, No. 2, and “Quantification of Color Vision with Cone Contrast Sensitivity” by Jeff Rabin (2004), 21, pp. 483-485, the disclosures of which are hereby incorporated by reference.
[0007] The CCT is a functional test, making it a broad, non-disease-specific test. These features make CCT an affordable screening tool able to detect cone sensitivity degradation associated with a broad spectrum of disease/toxicity early enough to, with treatment, potentially prevent permanent eye damage. The CCT may also be used as a predictive test for eye systemic, and neurological disease and retinal toxicity, as well as a monitoring test for disease/toxicity progression and treatment.
[0008] Consistent calibration of a color display monitor for administering the CCT is needed. Additionally, a low cost calibration system is needed due to inconsistent calibration over time. With standard “off-the-shelf” colormeters, interference from other software, including software produced by Microsoft Corporation, override calibration values and render the test invalid.
SUMMARY OF THE INVENTION
[0009] The invention broadly comprises a computerized method for administering a cone contrast (CCT) color vision test to a patient, comprising the steps of (a) displaying a first character in a first color at a first contrast level on a display driven by the computer; (b) receiving a first input signal from the patient via an input device connected to the computer, where the input signal is indicative of whether the patient recognizes the first character displayed in the first color at the first contrast level; (c) displaying a second character in the first color at a second contrast level on the display driven by the computer; (d) receiving a second input signal from the patient via an input device connected to the computer, where the input signal is indicative of whether the patient recognizes the second character displayed in the first color at the second contrast level; (e) assigning a score to the first and second input signals, the score related to sensitivity of a cone in the patient's eye to the first color at the first and second contrast levels; and, (f) storing the score in a storage device to track the cone sensitivity over time.
[0010] The invention also broadly comprises an apparatus for administering a cone contrast (CCT) color vision test to a patient, comprising (a) a general purpose computer specially programmed for displaying a first character in a first color at a first contrast level on a display driven by the computer; (b) means for receiving a first input signal from the patient via an input device connected to the computer, where the input signal is indicative of whether the patient recognizes the first character displayed in the first color at the first contrast level; (c) means for displaying a second character in the first color at a second contrast level on the display driven by the computer; (d) means for receiving a second input signal from the patient via an input device connected to the computer, where the input signal is indicative of whether the patient recognizes the second character displayed in the first color at the second contrast level; (e) means for assigning a score to the first and second input signals, the score related to sensitivity of a cone in the patient's eye to the first color at the first and second contrast levels; and, (f) means for storing the score in a storage device in communication with the computer to track the cone sensitivity over time.
[0011] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to embodiments illustrated.
[0012] The invention comprises a method and apparatus for screening and monitoring progress and treatment of systemic and neurological eye diseases. The method and apparatus include a Cone Contrast Test (CCT) which measures and scores color perception by cone type and assigns a score by cone type. The method and apparatus further include a comparison of such scores to a base line. Using CCT for the screening of potential disease/toxicity is an efficient, fast and low-cost procedure.
[0013] The apparatus comprises a computer, including input device and display device, for administering the CCT to individuals and, based on the test results and other factors, determining the early and late stages of one of Glaucoma, Retinopathy, Age-Related Macular Degeneration, Multiple Sclerosis, potentially Alzheimer's Disease and Parkinson's Disease, as well as Retinal Toxicity due to high-risk medications, as disclosed in the Appendices. The method is implemented by the apparatus.
[0014] The Cone Contrast Test presents random colored characters (for example, letters, numbers or symbols) to excite the red, green and blue cones in decreasing contrast sensitivity levels to identify the patients' Cone Contrast threshold and score for each cone type in each eye. The target is presented at a size well above a “normal” 20/20 acuity level so that the patient's cone contrast score is not affected by a limited acuity ability.
[0015] Upon each character presentation, the patient selects the corresponding character (for example, a letter, number or symbol) he sees from a response table or grid. If he does not see the character presentation, he may select “Pass”.
[0016] The patient interface consists of a computer mouse that may be used at a desk or in an exam room at a distance. Future patient interfaces may include a response keypad, notebook, tablet computer, touch screen, or voice recognition.
[0017] The Cone Contrast Test is fully automated, presenting each character for a specific, limited duration. Limiting the presentation time prevents a color deficient patient from potentially perceiving visual clues to aid him in his response and potentially affecting his score.
[0018] Further, elderly patients may not be familiar with computers, and thus may not be as responsive even though they are not color deficient. A “blanking period” option may be selected for patients requiring more time with the response unit. Specifically, after the character is presented for a fixed duration, the target letter is removed from the screen. The “blanking period” allows older patients, as well as patients with physical or cognitive limitations enough time to respond without introducing visual clues that could potentially alter their actual threshold and score.
[0019] Alternatively, an Orientation Screen, presented prior to the test for each eye, may detect the actual response time for the individual patient and adjust the presentation time for each target letter/number to achieve a Patient-Specific Presentation Time that would accommodate the need for additional response time due to computer, physical or cognitive limitations of each individual patient.
[0020] The blanking option or patient-specific presentation time is a key component for the Early Eye Disease Detection and Monitoring component of the Cone Contrast Test, as the majority of patients developing eye disease are elderly and may need extra time to respond due to unfamiliarity with a computer mouse or physical or cognitive limitations.
[0021] A staircase method is used to present color contrast levels by cone type, allowing the test to be administered more quickly. The contrast presentations are reduced by two levels at a time if the patient correctly identifies the character at that contrast level. The contrast level is increased if two or more characters within a contrast level are incorrectly identified.
[0022] The colors presented are precisely selected to excite only one cone type at a time, allowing each cone type to be measured and scored independently. Color calibration and contrast calibration are critical to the validity of the test results.
[0023] The equipment is calibrated for both color and contrast. The color presentation must be accurate so that each cone type is tested individually (i.e., only one cone type responds). In turn, the accuracy of the contrast levels is equally important to determine threshold level.
[0024] The current system includes software that does not allow other software to change color or contrast calibration settings, to achieve a reliable computerized color vision test using a low-cost colormeter.
[0025] The disclosed system utilizes display calibrating colormeter hardware, such as SPYDER 3™ and related versions, manufactured and sold by DATACOLOR of Lawrenceville, N.J.
[0026] Since the CCT begins with establishing a baseline for each cone type for an individual and looks for degradation of the individual's color perception through repeated testing over time, calibration for repeatability is critical. Computer equipment and colormeters can be changed, drift or fail over time, allowing color and contrast values to become out of calibration. To ensure that equipment stays within calibration and test results remain valid, the software forces an automatic in-field periodic calibration check. The CCT is self-calibrating, requiring the user only to position the photometer on the monitor and start the calibration. The calibration verification is done automatically and checks calibration values to original calibration values done at initial manufacturing. If the calibration is outside of tolerance, the system forces a complete calibration. If the calibration is still outside of tolerance, the system will alert the user and disable the use of the Cone Contrast Test until calibration can be completed within tolerance.
[0027] The duration between each calibration is established during set-up and may be adjusted based on clinic testing policy and procedure. The calibration time frame is pre-set for every seven days, but may be set according to individual testing policy and preference. Preferably, calibration automatically occurs at a predetermined interval of time. The automation alleviates the fear by some that the calibration may be skipped and test results may be rendered invalid.
[0028] Automated calibration verification enables a user of the invention to check for failing/failed hardware, including colormeter, monitor, or computer changes to ensure valid test scores. The calibration verification of the present system is preferably set at a seven (7) day interval, requiring calibration be checked against the original calibration settings. Any significant change from original calibration settings requires a full calibration. If a full calibration is still outside of tolerances, the Cone Contrast Test is disabled until a calibration can be completed within tolerance. Replacing equipment, such as a photometer, monitor or CPU, may be required to achieve a valid calibration.
[0029] Since the equipment may be used for both screening and monitoring of disease/toxicity, the equipment has both a screening mode and a comprehensive testing mode to allow for Medicare or other insurance billing, with the comprehensive mode providing more thorough examination and reporting. A doctor specifies the mode based on the use of the instrument for the specific exam before conducting the test.
[0030] Variations in the testing method may include, but are not limited to (1) altering distance between screen and individual (e.g., 3, 4 or 6 meters), (2) a user interface such as voice recognition commands, wireless keyboard or other wired or wireless input devices, (3) blanking period or patient-specific response time, and (4) screening and testing modes.
[0031] Each test is scored by cone type and any cone deficiency is determined by comparing the patient's scores over time. Accuracy of CCT is very high in detecting Red, Green and Blue cone deficiencies. Deficiencies which present over time are predictive of early eye, systemic and neurological disease as well as retinal toxicity, whereas such deficiencies may otherwise be overlooked as anomalies.
[0032] Storing of cone contrast sensitivity scores and reporting data in a way that shows cone contrast sensitivity changes over time allows for potential disease/toxicity alerts. Reports show a change in cone contrast sensitivity by patient, per eye, by cone type and display an alert when the cone contrast sensitivity change is statistically significant. The reports can be viewed or printed to alert doctors and patients of potential disease or toxicity that should be further investigated.
[0033] Currently, significant change is thought to be the normal distribution of color normal patients score, >15 points. Further research may show that changes less than 15 points may also be significant to a specific patient baseline.
[0034] This type of tracking and reporting mechanism has never before been available, limiting prior art systems and methods to hereditary color deficiency scoring use or research where time permits for manual comparison. The disclosed system and method is the first CCT usable as an early eye, systemic and neurological disease and retinal toxicity detection system in a clinic setting, where time with the patient is limited. Comparison data and alerts are critical to interpret test results in the time frame required in a clinical setting.
[0035] Patient reports are stored on the computer hard drive and may be uploaded to electronic medical records.
[0036] As previously discussed, patient response time is captured and recorded for each cone type for every Cone Contrast Test. Mean response time by cone type, and by eye, is calculated and reported. Response times have been shown to correlate closely with cone deficiency, with color normal patients responding consistently within two seconds and color deficient patients responding much slower. Cone Contrast Sensitivity Response Time may serve as a new sensitive metric of color deficiency and early indicator of eye, systemic or neurological disease.
[0037] The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' contribution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Various embodiments are disclosed, by way of example only, with reference to the accompanying drawings in which corresponding reference symbols indicate corresponding parts, in which:
[0039] FIG. 1 is a screen shot of the invention;
[0040] FIG. 2 is a screen shot of the invention;
[0041] FIG. 3 is a screen shot of the invention;
[0042] FIG. 4 is a screen shot of the invention;
[0043] FIG. 5 is a screen shot of the invention;
[0044] FIG. 6 is a screen shot of the invention;
[0045] FIG. 7 is a screen shot of the invention;
[0046] FIG. 8 is a screen shot of the invention;
[0047] FIG. 9 is a screen shot of the invention;
[0048] FIG. 10 is a screen shot of the invention;
[0049] FIG. 11 is a screen shot of the invention;
[0050] FIG. 12 is a screen shot of the invention;
[0051] FIG. 13 is a screen shot of the invention;
[0052] FIG. 14 is a screen shot of the invention;
[0053] FIG. 15 is a report of the invention;
[0054] FIG. 16 is a report of the invention;
[0055] FIG. 17 is a report of the invention;
[0056] FIG. 18 is a report of the invention;
[0057] FIG. 19 is a screen shot of the invention;
[0058] FIG. 20 is a screen shot of the invention;
[0059] FIG. 21 is a report of the invention;
[0060] FIG. 22 is a report of the invention;
[0061] FIG. 23 is a diagram of the invention; and,
[0062] FIG. 24 is a diagram of the invention;
DETAILED DESCRIPTION
[0063] At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the embodiments set forth herein. Furthermore, it is understood that these embodiments are not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the disclosed embodiments, which are limited only by the appended claims.
[0064] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which these embodiments belong.
[0065] Moreover, although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of these embodiments, some embodiments of methods, devices, and materials are now described.
[0066] As discussed above, a cone contrast test presents characters with colors specific to each cone type in decreasing contrast steps down to or near the patient's cone contrast threshold. It tests all three color values—red, green and blue—in both right and left eyes. Characters or optotypes are presented at 20/300 (red, green) and 20/400 (blue) to avoid acuity function interference. The CCT presents 5 contrast levels in increments of two contrast levels or jumps until the patient responds incorrectly. At that time, the contrast level presentations begin at the next higher contrast level and proceeds in a sequential fashion through the duration of the test. The patient's cone score is determined based on the number of correct responses at each level.
[0067] Adverting now to the Figures, the following Figures show screenshots of testing software 100 . FIG. 1 shows sign in screen 101 driven by a computer. Sign in screen 101 comprises user name field 102 , password field 103 , and sign in button 104 . Upon commencing testing software 100 , sign in screen 101 appears. In order to access testing software 100 , a patient taking a CCT or an administrator directing the CCT, must input a user name and a password into user name field 102 and password field 103 , respectively. A user can exit testing software 100 by selecting exit button 105 located at the top right of sign in screen 101 .
[0068] Once sign in button 104 is selected, presentation option screen 106 of testing software 100 appears as shown in FIG. 2 . Presentation option screen 106 comprises CCT near button 108 , CCT distance button 109 , contrast acuity near button 110 , contrast acuity distance button 111 , contrast sensitivity distance button 112 , and reports button 113 . The CCT may be conducted while a patient is seated at a desk with the computer displaying the CCT mounted thereon. In this case, a patient can use a computer mouse or some other means to select buttons in testing software 100 to be described in more detail below. Alternatively, the CCT may be conducted while a patient is seated or standing a distance from the computer displaying the CCT. In this case, an administrator directing or overseeing the CCT can operate a mouse connected to the computer displaying the CCT or some other interface may be involved to input a patient's responses. For example, voice recognition software could be used to transmit a patient's selections in or responses to the CCT, or a wireless mouse could be used. Regardless of the method used, acuity and cone contrast tests can be administered with a patient arranged proximate the display screen and at a distance away from the display screen. For near testing, a patient should be 18-24 inches from the display. For tests administered at a distance, a patient should be at least 9 feet from the display. If CCT near button 108 or contrast acuity near button 110 is selected, testing software 100 is directed to use characters at a default size based on the calibration of testing software 100 . If CCT distance button 109 is selected, testing software 100 is directed to display higher quality characters, down to 20/10, during the CCT depending on the patient's distance from the computer display. Selecting CCT distance button 109 will cause testing software 100 to produce a distance field and the patient's distance from the computer display will need to be inputted into the distance field and transmitted to testing software 100 so the proper quality characters are used. For best results, the patient should be parallel to the display. Selecting contrast acuity distance button 111 or contrast sensitivity distance button 112 will similarly direct testing software 100 to use higher quality characters, down to 20/10, during the acuity or sensitivity tests depending on the patient's distance from the computer display. Reports button 113 will be discussed in more detail below.
[0069] The CCT should be conducted in dim room lighting. No light should be directed at the CCT display. However, some lighting is acceptable and will not interfere with the test. Additionally,
[0070] Selection of the type of test desired (CCT near button 108 , CCT distance button 109 , contrast acuity near button 110 , contrast acuity distance button 111 , or contrast sensitivity distance button 112 ) will direct testing software 100 to produce subject data screen 116 . Subject data screen 116 comprises patient ID field 114 and patient name field 115 shown in FIG. 3 . Patient ID field 114 of testing software 100 is arranged to receive a 1-10 digit number identifying a patient. The number can but input using a keyboard, for example. Left and right arrows on a keyboard allow a user to move between digit entry fields. A patient's name, for example, John Doe is inputted into patient name field 115 using a keyboard, for example. It should be appreciated that other means such as, voice recognition software could be used to populate patient ID field 114 and patient name field 115 . To start the test, a patient or an administrator presses the “Enter” button on a keyboard. The test can be started without inputting data into patient ID field 114 and patient name field 115 . A user can exit testing software 100 by selecting exit button 105 located at the top right of subject data screen 116 .
[0071] The CCT test can be implemented using any characters preferably, letters or numbers. For Dyslexic patients, conducting the test using numbers may yield more favorable results. To present the test with letters, press the R-CCT button on the remote control or the STAIR button on the screen. Using the keyboard, press Shift F1. To present the test with numbers, first select the NUM button on the remote control. Then press R-CCT on the remote control or the STAIR button on the screen.
[0072] FIG. 4 shows an orientation testing screen 200 . Orientation testing screen 200 comprises an orientation instruction pane 201 , a confirmation button 203 , a testing field 211 , a testing symbol 212 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . In some embodiments of the invention, orientation testing screen 200 is displayed immediately upon commencement of the visual acuity test process. By displaying the orientation testing screen 200 prior to other portions of the visual acuity test, the method of taking the visual acuity test can be relayed and practiced by the patient taking the visual acuity test. Orientation instruction pane 201 contains written instructions on the specific steps the patient taking the visual acuity test should take during the testing process. Orientation instruction pane 201 also contains instructions for advancing to the other portions of the visual acuity test.
[0073] In the embodiment of the invention shown in FIG. 4 , the written instructions in orientation instruction pane 201 instruct the patient taking the visual acuity test to identify testing symbol 212 in testing field 211 and select the equivalent symbol from the plurality of response symbols 215 in response table 213 . In some embodiments of the invention, the specific symbols included in response table 213 will be selected randomly, but in all embodiments of the invention, a symbol equivalent to testing symbol 212 must be on of response symbols 215 in response table 213 .
[0074] This initial selection of one of the symbols of the plurality of response symbols 215 in response table 213 highlights the selected symbol for review by the patient. In some embodiments of the invention, selecting one of the plurality of response symbols 215 will cause testing software 100 to produce a sound corresponding to the symbol selected, such as saying the name of the letter if the plurality of response symbols 215 are letters. Selecting the same symbol again will act as a confirmation and indicate to testing software 100 that the patient believes the symbol selected from the plurality of response symbols 215 in response table 213 to be the same as the testing symbol 212 .
[0075] If the patient taking the visual acuity test cannot identify testing symbol 212 , the patient may select pass button 214 . This will indicate to testing software 100 that the patient is unable to identify testing symbol 212 . In some embodiments of the invention, selecting the pass button will be recorded as an incorrect identification for patient visual acuity assessment purposes.
[0076] Upon confirmation of a symbol from the plurality of response symbols 215 in response table 213 or selection of pass button 214 , testing software 100 will record the response and orientation testing screen 200 will refresh. Upon refreshing, orientation testing screen will display a new testing symbol 212 and response table 213 will comprise a different plurality of response symbols 215 . The patient taking the visual acuity test will then select one of the plurality of response symbols 215 in response table 213 or pass button 214 , continuing the orientation process. When the patient is confident that he or she understands the method of taking the visual acuity test, the orientation process can be ended by selecting the confirmation button 203 .
[0077] FIG. 5 shows a test commencement screen 230 . Test commencement screen 230 comprises a commencement message 231 , a confirmation button 203 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . Test commencement screen 230 is displayed immediately prior to the commencement of the testing portions of the visual acuity test to announce that the test process is ready to begin. The patient taking the visual acuity test will select confirmation button 203 when they are ready to begin the testing process. Although response table 213 and pass button 214 are components of test commencement screen 230 , they are not active, i.e., they cannot be selected.
[0078] FIG. 6 shows an eye selection screen 232 . Eye selection screen 232 comprises an eye selection message 233 , a confirmation button 203 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . Eye selection screen 232 is displayed immediately prior to each of the two eye-specific portions of the visual acuity test. As visual acuity can be different in the left and right eyes of the patient taking the visual acuity test, it is beneficial to test the left and right eyes individually. By testing the left and right eyes individually, a more thorough understanding of the patient's visual acuity can be obtained.
[0079] Eye selection message 233 indicates which eye will be tested in the following test portion. For example, if the right eye is to be tested in the following test portion, eye selection message 233 would instruct the patient to cover their left eye and perform the test with their right eye only. The patient taking the visual acuity test will select confirmation button 203 when they are ready to begin the testing process for the eye indicated in eye selection message 233 . Although response table 213 and pass button 214 are components of eye selection screen 232 , they are not active, i.e., they cannot be selected.
[0080] FIG. 7 shows a color phase screen 234 . Color phase screen 234 comprises a color phase message 235 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . Color phase screen 234 is displayed immediately prior to each of the three color-specific phases of the visual acuity test.
[0081] The ability of humans to perceive different colors of light is made possible by specialized cells in the retina called cone cells. Each of the three different types of cone cells detects a different portion of the visual spectrum, and each type is most sensitive to a certain color of light. The three different types of cone cells are most sensitive to colors that correspond approximately to the colors of red, green, and blue. Colors other than red, green, and blue are perceived via the combination in the human brain of signals from multiple types of cone cells and their relative intensities. For example, the color yellow is perceived when the red and green cone cells are stimulated approximately equally. The phenomenon of perceiving the full spectrum of visible light based on the combination of signals from three types of cells, each of which detects a different color, is called trichromacy.
[0082] As human vision is trichromatic, deficiencies in one or more of the types of cone cells can impair the ability of an individual to perceive certain colors. However, because each type of cone cell is most sensitive to a certain color of light, it is possible to individually assess the sensitivity of cone cells of a certain type by testing the ability to distinguish image components made of the color that the corresponding type of cone cell is most sensitive to. For this reason, the visual acuity test has three phases for each eye, a red phase, a green phase, and a blue phase. For example, in the red phase, the sensitivity of the red-type cone cells is assessed. In this way, the sensitivities of the red-type, green-type, and blue-type cone cells in each eye can be assessed.
[0083] Color phase message 235 announces to the patient taking the visual acuity test which color phase is about to begin. As the patient does not need to prepare for the specific color phases, the patient does not have to select any particular interface component to continue to the portion. The test process will continue automatically after a predetermined amount of time. Although response table 213 and pass button 214 are components of color phase screen 234 , they are not active, i.e., they cannot be selected.
[0084] FIG. 8 shows a testing screen 210 . Testing screen 210 comprises a testing field 211 , a testing symbol 212 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . Having familiarized themselves with the testing method during the orientation portion of the visual acuity test, the patient taking the test will be able to perform the test without further instruction. Testing symbol 212 , which is either red, green, or blue, depending on which color phase the testing process is currently in. For example, in the red color phase of the testing process, testing symbol 212 will be red.
[0085] The sensitivities of the different types of cone cells is assessed by showing the patient taking the visual acuity test a testing symbol 212 of the color corresponding the present color phase on testing field 211 . Initially, there is a large contrast differential between testing symbol 212 and testing field 211 . Due to this high contrast differential, it is easier for the patient to distinguish the shape of testing symbol 212 and select the equivalent symbol from the plurality of response symbols 215 in response table 213 . By iteratively reducing the contrast differential between testing symbol 212 and testing field 211 and asking the patient to select the equivalent symbol from the plurality of response symbols 215 in response table 213 , until the patient is unable to correctly identify testing symbol 212 , the ability of the specific cone cell types of the patient's specific eye can be assessed.
[0086] In some embodiments of the invention, the specific symbols included in response table 213 will be selected randomly, but in all embodiments of the invention, a symbol equivalent to testing symbol 212 must be on of response symbols 215 in response table 213 .
[0087] This initial selection of one of the symbols of the plurality of response symbols 215 in response table 213 highlights the selected symbol for review by the patient. In some embodiments of the invention, selecting one of the plurality of response symbols 215 will cause testing software 100 to produce a sound corresponding to the symbol selected, such as saying the name of the letter if the plurality of response symbols 215 are letters. Selecting the same symbol again will act as a confirmation and indicate to testing software 100 that the patient believes the symbol selected from the plurality of response symbols 215 in response table 213 to be the same as the testing symbol 212 .
[0088] If the patient taking the visual acuity test cannot identify testing symbol 212 , the patient may select pass button 214 . This will indicate to testing software 100 that the patient is unable to identify testing symbol 212 . In some embodiments of the invention, selecting the pass button will be recorded as an incorrect identification for patient visual acuity assessment purposes. Additionally, in some embodiments of the invention, if the patient does not select any of the plurality of response symbols 215 in response table 213 in a predetermined amount of time, such inaction will be recorded as an incorrect identification for patient visual acuity assessment purposes. The predetermined amount of time before an incorrect identification is registered may be varied depending on the purpose of the visual acuity test. For example, if the purpose of the test is to measure the ability of piloting students to distinguish colors, the ability to make timely determinations may be more important than if the purpose of the test is to test generally for color-blindness. In such a case, the predetermined amount of time before an incorrect identification is registered may be reduced.
[0089] If the patient correctly identifies testing symbol 212 by selecting the equivalent symbol from the plurality of response symbols 215 in response table 213 , testing software 100 will record a correct identification and continue the test process. In one embodiment of the invention, two correct identifications in succession by the patient at a specific contrast differential level will cause testing software 100 to display a testing screen 210 with a testing symbol 212 two contrast differential levels lower than the immediately preceding testing symbol 212 .
[0090] If the patient selects an incorrect response symbol from the plurality of response symbols 215 in response table 213 , then testing software 100 will record an incorrect identification. If the patient selects pass button 214 , then testing software 100 will record that the patient chose to pass. In an embodiment of the invention, if the patient selects an incorrect response symbol from the plurality of response symbols 215 in response table 213 , the testing software will display a testing screen 210 with a testing symbol 212 one contrast differential level higher than the immediately preceding testing symbol 212 .
[0091] In yet another embodiment of the invention, if the patient correctly identifies two testing symbols 212 of a given contrast differential level, even if such correct identification is separated by an incorrect identification, or a selection of pass button 214 , or the registering of an incorrect identification by the lapsing of the predetermined amount of time, then the testing software will display a testing screen 210 with a testing symbol 212 one contrast differential level lower than the immediately preceding testing symbol 212 .
[0092] Generally, testing software 100 will start each phase of the test process by displaying a testing screen 210 with a testing symbol 212 of a maximum contrast differential with testing field 211 . Upon registering a predetermined number of correct identifications of testing symbols 212 , testing software 100 will begin displaying a series of testing screens 210 with testing symbols 212 of a lower contrast differential with testing field 211 . Upon registering a predetermined number of incorrect identifications, or selections of pass button 214 , or lapses of the predetermined amount of time, testing software 100 will begin displaying a series of testing screens 210 with testing symbols 212 of a higher contrast differential with testing field 211 . The testing process in a specific color phase will end after a predetermined number of correct identifications are registered at a specific contrast differential level. Registering a large number of correct identifications at a specific contrast differential level indicates that the patient cannot reliably distinguish and identify a testing symbol 212 of lower contrast differential levels. The testing process in a specific color phase may also end after pass button 214 has been selected a predetermined number of times. Repeatedly selecting pass button 214 indicates that the patient can no longer reliably distinguish and identify the series of testing symbols 212 that are being displayed.
[0093] FIG. 9 shows a refreshed testing screen 210 comprising a testing field 211 , a testing symbol 212 of reduced contrast differential with testing field 211 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . The patient taking the visual acuity test will attempt to correctly distinguish and identify testing symbol 212 and select the corresponding symbol from the plurality of response symbols 215 . If the patient is unable to distinguish and identify testing symbol 212 , they may select pass button 214 to cause testing software 100 to display a new testing screen 210 .
[0094] FIG. 10 shows a refreshed testing screen 210 comprising a testing field 211 , a testing symbol 212 of further reduced contrast differential with testing field 211 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . The patient taking the visual acuity test will attempt to correctly distinguish and identify testing symbol 212 and select the corresponding symbol from the plurality of response symbols 215 . If the patient is unable to distinguish and identify testing symbol 212 , they may select pass button 214 to cause testing software 100 to display a new testing screen 210 .
[0095] FIG. 11 shows a refreshed testing screen 210 comprising a testing field 211 , a testing symbol 212 of even further reduced contrast differential with testing field 211 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . The patient taking the visual acuity test will attempt to correctly distinguish and identify testing symbol 212 and select the corresponding symbol from the plurality of response symbols 215 . If the patient is unable to distinguish and identify testing symbol 212 , they may select pass button 214 to cause testing software 100 to display a new testing screen 210 .
[0096] FIG. 12 shows a refreshed testing screen 210 comprising a testing field 211 , a testing symbol 212 of minimal contrast differential with testing field 211 , a response table 213 , and a pass button 214 . The response table 213 comprises a plurality of response symbols 215 . The patient taking the visual acuity test will attempt to correctly distinguish and identify testing symbol 212 and select the corresponding symbol from the plurality of response symbols 215 . If the patient is unable to distinguish and identify testing symbol 212 , they may select pass button 214 to cause testing software 100 to display a new testing screen 210 .
[0097] Upon completion of a specific color phase in the testing process, testing software 100 will continue to the next color phase for the currently tested eye. If all color phases have been completed for the currently tested eye, testing software 100 will display eye selection screen 232 and continue the testing process with the next eye to be tested. If all color phases for both eyes have been completed, the test process is complete.
[0098] FIG. 13 shows a test conclusion screen 236 . Test conclusion screen 236 comprises a conclusion message 237 , a response table 213 , and a pass button 214 . Conclusion message 237 informs the patient that the test process is complete. Although response table 213 and pass button 214 are components of test commencement screen 230 , they are not active, i.e., they cannot be selected.
[0099] Viewing and Interpreting Results
[0100] Reports may be generated by patient, type of report, and dates. To generate a report for a particular patient, testing software 100 is arranged to select data connected to a patient ID. You may display a list of all tests for a patient as shown in FIG. 19 . Or, to print Comparison Reports, select the type of report to be displayed, then select the date range for the report. Use the mouse or TAB key to move between the types of reports. Double click or hit ENTER on the specific report date to view specific exam results. Selecting Dates for Comparison Reports To view comparison results select the date range to be displayed. To display reports within a narrower time frame, for example since the beginning of treatment, you may select a subset of the available tests. Hold down the SHIFT key to select a date range or hold down the CTRL key to select specific tests. Use the PgUp and PgDn buttons to select larger date ranges. When the desired test dates are selected, click or TAB to the Submit for Report Generation button to view the report.
[0101] Reports button 113 shown in FIG. 2 can be accessed to review and generate test results. Similarly, FIG. 14 shows report generator screen 500 . Report generator screen 500 comprises select all test dates button 501 and submit for report generation button 502 . If select all test dates button 501 is selected, testing software 100 is directed to include all test data in generating reports for interpretation. If select all test dates button 501 is not selected, particular test dates can be selected from report generator screen 500 . Once particular test dates are selected from report generator screen 500 , for example, selected test date 503 , selection of submit for report generation button 502 directs testing software 100 to generate reports.
[0102] Reports are shown in FIGS. 15-18 , 21 - 22 . Significantly, CCT scores are shown in red, green and blue. Red CCT scores are shown with a single dashed line connecting circles. Green CCT scores are shown as a bar connecting squares. Blue CCT scores are shown as a double dashed line connecting triangles. The circles, squares and triangles refer to CCT scores. The lines connecting the CCT scores are generated to show trends and whether a patient's aptitude for color vision is deteriorating. Some reports include bar graphs ( FIG. 16 ) and line graphs ( FIG. 17 ). The colors red, yellow and green are also used to indicate color deficiency, possible deficiency, and normal vision, respectively.
[0103] Acquired and hereditary color deficiency can be interpreted based on a less than normal cone score in a single visit or as a drop in a specific cone score of 10 point or more from a patient's base-line. Normal color vision is indicated by a CCT score between 90-100. Possible color vision deficiency is indicated by a CCT score between 75-89. Color deficiency, hereditary or acquired, is indicated by a CCT score between 0-74. Acquired and hereditary color deficiency overlap. However, there are several characteristics that can help identify acquired vs. hereditary color deficiency. Hereditary color deficiency is indicated by selective decreases on red or green tests. Moreover, cone sensitivity scores are substantially symmetrical in the left and right eyes. In contrast, acquired color deficiency is not as selective to cone types and may show decreases on red, green and blue tests. Acquired color deficiency also usually features asymmetrical cone sensitivity scores in the left and right eyes.
[0104] Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, which modifications are intended to be within the spirit and scope of the invention as claimed. It also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting. Therefore, other embodiments of the present invention are possible without departing from the spirit and scope of the present invention.
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A method and apparatus for administering eye tests to identify cone sensitivity loss associated with hereditary and acquired color vision loss which may be used for early detection, progress, treatment, and monitoring of eye conditions, traumatic brain injury, optic neuritis, systemic and neurological diseases including Glaucoma, Retinopathy, Age-Related Macular Degeneration, Multiple Sclerosis, Alzheimer's Disease, and Parkinson's Disease and retinal toxicity. Particularly, the method and apparatus disclosed uses a Cone Contrast Test (CCT) to test individuals for hereditary or acquired color vision loss associated with (a) early signs of potential disease/damage/toxicity in an effort to (i) provide opportunity for treatment, and (ii) prevent permanent eye damage, and (b) monitor progress and treatment of such disease/damage/toxicity. The system comprises a computer system including an input device and a display device, and the accuracy and repeatability of the testing is provided by repeated calibration using a colormeter.
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[0001] This application claims the benefit under 35 U.S.C. § 119(e) of the U.S. provisional patent application No. 60/553,720 filed Mar. 15, 2004.
TECHNICAL FIELD
[0002] The present invention relates to heating, ventilating and air conditioning air spaces, and more particularly to systems, devices and methods for moving air in a columnar pattern with minimal lateral dispersion that are particularly suitable for penetrating air spaces and air temperature de-stratification.
BACKGROUND ART
[0003] The rise of warmer air and the sinking of colder air creates significant variation in air temperatures between the ceiling and floor of buildings with conventional heating, ventilation and air conditioning systems. Such air temperature stratification is particularly problematic in large spaces with high ceilings such as warehouses, gymnasiums, offices, auditoriums, hangers, commercial buildings, and even residences with cathedral ceilings, and can significantly decrease heating and air conditioning costs. Further, both low and high ceiling rooms can have stagnant or dead air. For standard ceiling heights with duct outlets in the ceiling there is a sharp rise in ceiling temperatures when the heat comes on.
[0004] One proposed solution to air temperature stratification is a ceiling fan. Ceiling fans are relatively large rotary fans, with a plurality of blades, mounted near the ceiling. The blades of a ceiling fan have a flat or airfoil shape. The blades have a lift component that pushes air upwards or downwards, depending on the direction of rotation, and a drag component that pushes the air tangentially. The drag component causes tangential or centrifugal flow so that the air being pushed diverges or spreads out. Conventional ceiling fans are generally ineffective as an air de-stratification device in relatively high ceiling rooms because the air pushed by conventional ceiling fans is not maintained in a columnar pattern from the ceiling to the floor, and often disperses or diffuses well above the floor.
[0005] Another proposed solution to air temperature stratification is a fan connected to a vertical tube that extends substantially from the ceiling to the floor. The fan may be mounted near the ceiling, near the floor or in between. This type of device may push cooler air up from the floor to the ceiling or warmer air down from the ceiling to the floor. Such devices, when located away from the walls in an open space in a building, interfere with floorspace use and are not aesthetically pleasing. When confined to locations only along the walls of an open space, such devices may not effectively circulate air near the center of the open space. Examples of fans connected to vertical tubes are disclosed in U.S. Pat. No. 3,827,342 to Hughes, and U.S. Pat. No. 3,973,479 to Whiteley.
[0006] A device that provides a column of air that has little or no diffusion from the ceiling the floor, without a vertical tube, can effectively provide air de-stratification. U.S. Pat. Nos. 4,473,000 and 4,662,912 to Perkins disclose a device having a housing, with a rotating impeller having blades in the top of the housing and a plurality of interspersed small and large, vertically extending, radial stationary vanes spaced below the impeller in the housing. The device disclosed by Perkins is intended to direct the air in a more clearly defined pattern and reduce dispersion. Perkins, however, does not disclose the importance of a specific, relatively small gap between the impeller blades and the stationary vanes, and the device illustrated creates a vortex and turbulence due to a large gap and centrifugal air flow bouncing off the inner walls of the housing between the blades and vanes. Perkins also discloses a tapering vane section. The tapering vane section increases velocity of the exiting air stream.
[0007] A device with a rotary fan that minimizes the rotary component of the air flow while maximizing the axial air flow quantity and velocity can provide a column of air that flows from a high ceiling to a floor in a columnar pattern with minimal lateral dispersion that does not require a physical transporting tube. Such a device should reduce the energy loss by minimizing the rotary component of the air flow, and therefore minimizes turbulence. Such a device should minimize back pressure, since a pressure drop at the outlet of the device will cause expansion, velocity loss and lateral dispersion. The device should have minimum noise and low electric power requirements.
DISCLOSURE OF THE INVENTION
[0008] An air moving device which has a housing with an air inlet and an air outlet spaced from the inlet. A rotary impeller with a plurality of blades is mounted in the housing at the air inlet end and produces air flow with an axial component and a rotary component. A plurality of spaced, longitudinally extending, radial air guide vanes in the housing downstream of the impeller are in close proximity to the impeller blades to minimize the rotary component and change the air flow to a laminar and axial flow in the housing that exits the outlet end in a columnar pattern with minimal lateral dispersion. A method of moving air includes producing an air flow through a housing, and directing the air flow through the housing in a laminar and axial flow and exits an outlet so as to produce a columnar pattern with minimal lateral dispersion. The method also includes directing warm air from near the ceiling toward the floor, allowing the heat from the warm air to be stored in the floor, articles on the floor and the earth under the floor. The method includes directing air in a generally horizontal direction to allow penetration of an air space in a container, trailer truck or a room to promote flushing of that air space and circulation thereof. The device and method are particularly suitable for high efficiency, low power usage, air temperature de-stratification, and to improve air quality and circulation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Details of this invention are described in connection with the accompanying drawings that bear similar reference numerals in which:
[0010] FIG. 1 is a top perspective view of an air moving device embodying features of the present invention.
[0011] FIG. 2 is a side elevation view of the device of FIG. 1 .
[0012] FIG. 3 is a bottom view of the device of FIG. 1 .
[0013] FIG. 4 is an exploded perspective view of the device of FIG. 1 .
[0014] FIG. 5 is a sectional view taken along line 5 - 5 of FIG. 2 .
[0015] FIG. 6 is a sectional view taken along line 6 - 6 of FIG. 2 .
[0016] FIG. 7 is a sectional view taken along line 5 - 5 of FIG. 2 , with straight upstream portions of the vanes.
[0017] FIG. 8 is a side elevation view of the device of FIG. 1 showing angular direction of the device.
[0018] FIG. 9 is an enlarged, partial exploded view of the hangar attachment of the device of FIG. 1 .
[0019] FIG. 10 is a side view of a room with the device of FIG. 1 showing an air flow pattern with dashed lines and arrows.
[0020] FIG. 11 is a side elevation view, partially cut away, showing the device of FIG. 1 modified for attachment to a light can.
[0021] FIG. 11A is a sectional view taken along line 11 A- 11 A of FIG. 11 .
[0022] FIG. 12 is a side elevation view of the device of FIG. 1 with an intake grill.
[0023] FIG. 13 is a sectional view taken along line 6 - 6 of FIG. 2 of the device of FIG. 1 with a misting nozzle.
[0024] FIG. 14 is a side elevation view of the device of FIG. 1 in combination with a tube and second air moving device.
[0025] FIG. 15 is a bottom perspective view, partially cut away, showing the device of FIG. 1 mounted in a drop ceiling.
[0026] FIG. 15A is a top perspective view of FIG. 15 .
[0027] FIG. 15B is a top perspective view of the fastening member shown in FIG. 15A
[0028] FIG. 15C is a sectional view taken along FIG. 15C-15C of FIG. 15A .
[0029] FIG. 15D is a sectional view along line 15 D- 15 D of FIG. 15A .
[0030] FIG. 16 is an enlarged view of a portion of FIG. 15 .
[0031] FIG. 17 is a side elevation view, partially cut away, showing the device of FIG. 1 modified for attachment to a light socket and having a light bulb at the lower end.
[0032] FIG. 18 is a schematic view of an open sided tent with an air moving device in the top.
[0033] FIG. 19 is a schematic view of a shipping container with an air moving device at one lower end.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Referring now to FIGS. 1 to 9 , there is shown an air moving device 12 having an elongated outer housing 13 , an electric rotary fan 14 in the housing for producing air flow in the housing and a plurality of longitudinally extending, outer radial vanes 15 and an inner housing hub 16 opposite the vanes in the housing downstream of the fan for directing air flow in the housing.
[0035] The housing 13 has a circular cross section, and an open first end 17 and an open second end 18 spaced from the first end 17 . In the illustrated embodiment, a detachable, axially outwardly convex cowling 19 forms the first end 17 and provides an air inlet 21 with a diameter slightly smaller than the outer diameter of the cowling 19 .
[0036] The housing 13 has a first section 25 extending from the cowling 19 to an interior shelf 26 . A generally C-shaped hanger 23 mounts at opposite ends 24 to opposite sides of the housing 13 at the upper end of the first section 25 , for mounting the air moving device 12 to a support. The first section 25 , when viewed from the side, has a curved, slightly radially outwardly convex shape that conforms to the curvature of the cowling 19 . The shelf 26 extends radially inwardly to join with the upstream end of a second section 27 . The second section 27 tapers inwardly and extends axially from the shelf 26 to the second end 18 along a smooth curve that goes from radially outwardly convex near the shelf 26 to radially outwardly concave near the second end 18 . The second end 18 forms an air outlet 28 that has a smaller diameter than the air inlet 21 . A plurality of circumferentially spaced external fins 29 extend from the shelf 26 to the second section 27 to provide the appearance of a smooth curve from the air inlet 21 to the air outlet 28 when the housing 13 is viewed from the side.
[0037] The fan 14 includes an impeller 31 having a cylindrical, inner impeller hub 32 , with an electric motor 34 therein, and a plurality of rigidly mounted, circumferentially spaced blades 33 extending radially from the impeller hub 32 . In the illustrated embodiment the impeller 31 has three equally spaced blades 33 and rotates about an axis in a counter-clockwise direction when viewed from above. Each blade 33 , in side view, extends from an upstream edge 35 , downwardly and leftwardly to a downstream edge 36 with each blade 33 being slightly concave, in an airfoil or wing shape, downwardly to propel air rightwardly as shown by the arrow. Each blade 33 then inclines at a selected angle to the axis of rotation of the impeller. Each blade 33 shown extends axially and radially toward the outlet or second end 18 to direct air axially with a rotary component. If the motor 34 runs in the opposite direction, the incline of the blades 33 would be reversed. The fan 14 includes a stationary cylindrical mounting ring 38 that extends around the blades 33 , with the impeller hub 32 being rotably mounted relative to the mounting ring 38 . The mounting ring 38 has spaced, protruding upstream and downstream rims 40 and 41 . The fan 14 mounts in the housing 13 between the cowling 19 and the shelf 26 .
[0038] Each of the vanes 15 is identical and includes upstream portion 43 and a downstream portion 44 . The upstream portion 43 is carried in a stator 46 . The stator 46 has a cylindrical stator hub 47 with a diameter substantially equal to the diameter of the impeller hub 32 . The upstream portions 43 of the vanes 15 are mounted in a circumferentially spaced arrangement around the stator hub 47 , and extend longitudinally along and radially from the stator hub 47 . Each upstream portion 43 has an upstream end 48 and a downstream end 49 . A support body 50 includes a cylindrical stator ring 52 that extends around the upstream portions 43 and connects to the outer ends of the upstream portions 43 of the vanes 15 near the upstream ends 48 . The support body 50 also includes a protruding stator rim 53 that is substantially planar with the upstream ends 48 of the upstream portions 43 of the vanes 15 , and that connects to the stator ring 52 and extends radially outwardly therefrom.
[0039] The housing 13 has an inner surface and the inner housing hub 16 has an outer surface concentric with a spaced from the housing inner surface to define an air flow passage through the housing. The inner housing hub 16 includes the fan hub 32 , stator hub portion 47 and downstream hub portion 57 , each having an outer surface and arranged end to end along the center of the housing and opposite and spaced from the housing inner surface to define the air flow passage. In particular, these outer surfaces shown are cylindrical and substantially the same diameter for a substantial portion of the passage and as the housing 13 converges the downstream hub portion 57 converges to generally follow the curvature of the inside surface of the housing.
[0040] The stator 46 nests in and is separable from the housing 13 with the stator rim 53 between the shelf 26 of the housing 13 and the downstream rim 41 of the mounting ring 38 of the fan 14 , and with a gap 55 having a selected size between the downstream edge 36 of the blades 33 of the impeller 31 and the upstream ends 49 of the upstream portions 43 of the vanes 15 . If the gap 55 is too large, turbulence will be generated in the air flow between the impeller 31 and the vanes 15 , reducing the velocity of the air flow. If the gap 55 is too small, fluid shear stress will generate noise. The size of the gap 55 is generally selected as no greater than a maximum selected dimension to avoid turbulence and no less than a selected minimum dimension to avoid noise, and more particularly selected as small as possible without generating noise.
[0041] The selected size of the gap 55 is generally proportional to the diameter of the impeller 31 and may further be affected by the speed of the impeller 31 . The following are examples: For an impeller 31 with a diameter of 6.00″, at 1800 rpm, the maximum size of the gap 55 should be 1.25″ and the minimum gap should be 0.2″. For an impeller 31 with a diameter of 8.5″, at 1400 rpm, the maximum size of the gap 55 should be 1.25″, and the minimum gap should be 0.2″ but could be 0.020 for lower rpm's as the size of the gap is rpm dependent. Generally, the maximum size of the gap 55 should be less than one half the diameter of the impeller 31 .
[0042] In the illustrated embodiment, eight equally spaced upstream portions 43 of the vanes 15 are provided, and when viewed from the side, the upstream portions 43 of the vanes 15 extend straight upwardly from the downstream ends 49 and then curve leftwardly near the upstream ends 48 . The upstream portion 43 of each curved vane portion is inclined at an angle opposite the incline of the blade 33 that extends axially and radially inward toward the outlet or second end 28 to assist in converting the rotary component of the air flow into laminar and axial flow in the housing.
[0043] Straight upstream portions 43 A of the vanes 15 may also be used, as shown in FIG. 7 , and other numbers of vanes 15 may be used. Further, if the motor 34 runs in the opposite direction, the incline of the curvature near the upstream ends 48 would be reversed.
[0044] The downstream portions 44 of the vanes 15 attach at an inner end to a downstream inner housing hub portion 57 , are circumferentially spaced and extend radially outwardly from the housing hub portion 57 to the housing 13 . The housing hub portion 57 and the downstream portions 44 of the vanes 15 extend axially from the stator 46 to or near the air outlet 28 . The housing hub portion 57 has a circular cross section, has a diameter substantially equal to the diameter of the stator housing hub portion 47 at the upstream end adjacent to the stator housing hub portion 47 , and tapers downstream to a point 58 near the air outlet 28 . This hub portion may be characterized as torpedo shaped. In the illustrated embodiment there are four downstream portions 44 of the vanes 15 circumferentially spaced at 90 degrees, with each downstream portion 44 being aligned with an upstream portion 43 of a vane 15 . Other numbers of downstream portions 44 of the vanes 15 can be used.
[0045] The number of the blades 33 may be 2, 3, 4, 5, 6, 7 or 8. The number of the vanes 15 may be 2, 3, 4, 5, 6, 7 or 8. The number of vanes 15 should be different from the number of blades 33 . If the number of vanes 15 and blades 33 are the same, added noise is generated due to harmonics.
[0046] The air moving device 12 discharges air at a high velocity in a generally axial flow having a columnar pattern with minimal lateral dispersion after exiting the air outlet 28 . The cowling 19 extends along a curve toward the inside to reduce turbulence and noise for air flow entering the air inlet 21 . The impeller hub 32 , the stator hub 47 and the housing hub 57 form the inner housing hub 16 . The taper of the housing hub 57 generally follows the taper of the housing 13 so that the cross sectional area for air flow decreases about 10% to 35% through the air moving device 12 to avoid back pressure and at the same time increase air flow velocity. In the embodiment shown the air flow decreases about 22%.
[0047] The vanes 15 convert the rotary component of the air flow from the impeller 31 into laminar and axial air flow in the housing. The leftward curve of the upstream ends 48 of the upstream portions 43 of the vanes 15 , in the illustrated embodiment, reduces the energy loss in the conversion of the rotary component of the air flow from the impeller 31 into laminar and axial air flow in the housing. The small gap 55 between the impeller 31 and vanes 15 prevents the generation of turbulence in the air flow in the gap 55 . The taper of the housing 13 in combination with the taper of the housing hub 57 to the point 58 allows the air flow to exit the air outlet 28 in a continuous, uninterrupted columnar pattern with minimal dispersion, with no center hole or gap at a linear speed greater than would be imparted by a fan alone. The inside surface of the housing 13 is a substantially smooth uninterrupted surface to minimize turbulence and energy loss.
[0048] The hanger 23 is mounted to rotate and lock relative to the housing 13 , so that when the hanger 23 is attached to an overhead support such as ceiling, the air flow from the air moving device 12 may be directed vertically or aimed at any selected angle from the vertical as shown in FIG. 8 . As shown in FIGS. 1 and 9 , the first section 25 of the housing 13 includes mounting tabs 91 on opposite sides on the upper edge of the first section 25 . Each mounting tab 91 includes a round, outwardly directed mounting face 92 , and a housing aperture 93 that extends inwardly through the center of the mounting tab 91 . A pair of outwardly projecting housing ridges 94 extend radially on the mounting face 92 on opposite sides of the housing aperture 93 .
[0049] Each end 24 of the hanger 23 has a round, inwardly facing hanger end face 96 , similar in size to the mounting face 92 on the housing 13 . A hanger end aperture 97 extends through the center of the hanger end face 96 . A plurality of spaced, radially extending grooves 98 , sized to receive the housing ridges 94 , are provided on each hanger end face 96 . Bolt 100 extends through the hanger end aperture 97 and threads into an internally threaded cylindrical insert 101 , rigidly affixed in housing aperture 93 . The angle of the housing 13 is chosen by selecting a pair of opposed grooves 97 on each hanger end 24 to receive the housing ridges 94 . The pivotal arrangement enables the housing to move to a selected angle and is lockable at the selected angle to direct air flow at the selected angle.
[0050] FIG. 10 shows an air moving device 12 mounted to the ceiling 62 of a room 63 shown as being closed sided with opposed side walls. Warm air near the ceiling 62 is pulled into the air moving device 12 . The warm air exits the air moving device 12 in a column 64 that extends to the floor 65 . When the column 64 reaches the floor 65 , the warm air from the ceiling pushes the colder air at the floor 65 outward towards the opposed side walls 66 and upward towards the ceiling 62 . When the column 64 reaches the floor 65 , the warm air from the ceiling will also transfer heat into the floor 65 , so that heat is stored in the floor 65 . The stored heat is released when the ceiling is cooler than the floor. The heat may also be stored in articles on the floor and earth under the floor. The air moving device 12 destratifies the air in a room 63 without requiring the imperforate physical tube of many prior known devices. The air moving device 12 destratifies the air in a room 63 with the warmer air from the ceiling 62 minimally dispersing before reaching the floor 65 , unlike many other prior known devices. The air moving device 12 will also remove dead air anywhere in the room. It is understood that the air moving device 12 may also be mounted horizontally in a container, trailer truck or room as is describe hereafter.
[0051] Referring to FIG. 11 , an air moving device 12 is fitted with an inlet grill 68 and an electric connector 69 for attachment to a light can 70 with a light bulb socket 71 at the upper end. The inlet grill 68 includes a plurality of circumferentially spaced grill fins 72 that attach to the first end 17 of the housing 13 . The grill fins 72 are separated by air intake slots 73 , and extend axially outwardly from the first end 17 and curve radially inwardly and are integral with a flat circular mounting plate 74 that is substantially parallel with the first end 17 . The electrical connector 69 has a tube 76 that is integral at one end with the center of the mounting plate 74 and extends axially therefrom, and a light bulb type, right hand thread externally threaded male end 77 attached to the other end of the shaft 78 . Grill 68 , plate 74 and tube 76 are shown as made of a one piece construction. Plate 74 has holes that received screws 83 or like fasteners to fasten plate 74 to ceiling 62 .
[0052] The shaft 78 telescopes in the tube 76 . The tube 76 has a pair of opposed keyways 76 A that receive keys 78 A on the shaft 78 which allow axial sliding movement of the shaft 78 in the tube 76 . A compression spring 75 fits in the tube and bears against the bottom of shaft 78 and top of plate 74 . Preferably the shaft 78 has a selected length relative to the length of the can 70 such that when the air moving device 12 is mounted in a can 70 in a ceiling 62 , the threaded male end 77 engages the socket 71 before the mounting plate 74 contacts the ceiling 62 and when the threaded male end 77 is screwed into the socket 71 , the mounting plate 74 bears against the ceiling 62 . The spring 75 is compressed between plate 74 and shaft 78 . Screws 83 fasten the plate to the ceiling 62 . Since the light can 70 may be open to air above the ceiling 62 , the mounting plate 74 is preferably sized to cover the open lower end of the can 70 , so that only air from below the ceiling 62 is drawn into the air moving device 12 . The air moving device 12 fitted with the inlet grill 68 and the electrical connector 69 can also be used with a ceiling light socket.
[0053] The air moving device 12 may include an intake grill 79 for preventing objects from entering the impeller 31 , as shown in FIG. 12 . The intake grill 79 shown has a substantially hemispherical shape, and includes a plurality of circumferentially spaced grill fins 80 separated by intake slots 81 . The grill fins 80 extend axially outwardly and curve radially inwardly from the first end 17 of the housing 13 to a central point 82 spaced from the first end 17 . Other shapes of intake grills are suitable for the present invention.
[0054] FIG. 13 shows an air moving device 12 with a misting nozzle 84 . The nozzle 84 extends through the point 58 of the housing hub 57 to spray water into the column of air exiting the air outlet 28 to cool the air through evaporation. The media exiting the nozzle 84 and being supplied through tube 85 can have other purposes such as a disinfectant or a fragrance or a blocking agent for distinctive needs. The nozzle 84 connects to a water line 85 , in the housing hub 59 that connects to a water source (not shown).
[0055] FIG. 14 shows an air moving system 86 for use in buildings with very high ceilings, including an air moving device 12 , an upwardly extending, tube 87 (shown cut away) connected at a lower end to the air inlet 21 of the air moving device 12 , and a truncated upper air moving device 88 having an air outlet 89 connected to the upper end of the tube 87 . The housing of device 88 is called truncated because it may be shortened or cut off below the fins 29 . A conventional air moving device 12 may be used for device 88 . The tube 87 may be flexible and is preferably fire resistant. The air moving system 86 is mounted to a ceiling or like support with the air outlet 28 of the air moving device 12 spaced above the floor, preferably about 10 to 50 feet. The tube may be for example from 30 to 100 feet long. The upper air moving device 88 at the top of the system 86 has a higher air moving flow capacity than the air moving device 12 at the bottom of the cascading system 86 . By way of example, and not as a limitation, the upper air moving device 88 may have a capacity of 800 cfm and the air moving device 12 may have a capacity of 550 cfm.
[0056] FIGS. 15, 15A , 15 B, 15 C, 15 D and 16 show the air moving device 12 mounted in an opening 103 in a ceiling 104 . A generally cylindrical can 105 mounts on and extends above the ceiling 104 , and has an open can bottom 106 , and a closed can top 107 . The can top 107 includes a semi-circular, downward opening, circumferentially extending channel 108 . A semi-circular fin 111 extends radially across the channel 108 to prevent swirling of the air before entering the air inlet 21 . Additional fins may be used. A grill and support assembly 125 mounts to the ceiling and extends and connects to the exterior of the housing of device 12 . A grill including spaced openings 110 between fins 109 to allow air to flow up from the room along the housing and past the cowling 19 into the inlet 21 . The grill and support assembly 125 includes an outer ring 120 fastened to the underside of the ceiling including the convexly curved grill fins 109 with air openings 110 between connected outer ring 120 and an inner ring 121 . Ring 121 has a spherical concave inner bearing surface 122 . A ring 123 has a spherical convexly curved exterior bearing surface 124 is mounted on and affixed to the housing with bearing surfaces 122 and 124 mating in a frictional fit to support the housing to be at a vertical position or tilted at an angle to the vertical axis and be held by friction at the vertical axis or a selected angle relative to the vertical axis to direct air flow as required.
[0057] The can 105 has an outwardly extending bottom flange 140 that fits against the underside of the ceiling 104 . The can 105 preferably has four circumferentially spaced bottom openings 141 at 90 degree intervals that are rectangular in shape and extend up the can wall a short distance from the bottom flange 140 . A clamping member 142 preferably made as a molded plastic body has a main body portion 143 above the ceiling 104 outside the can wall and an end flange portion 144 that fits inside the can opening 142 . The main body portion 143 has a U-shaped outer wall portion 145 and an inner hub portion 146 having an aperture 147 . The clamping member 142 inserts into the opening 141 via the open end of the can. A bolt fastener 151 extends through a hole in the flange, through a hole in the ceiling and threads into the aperture 147 in the main body portion to clamp the can 105 to the ceiling 104 .
[0058] As shown in FIG. 15D the grill and support assembly 125 is mounted to the ceiling 104 and can 105 by a bolt fastener 149 extending through an aperture in ring 120 , through the ceiling 104 and into a nut 150 in flange 140 in the can. Preferably there are four bolt fasteners 149 at 90 degree intervals midway between fasteners 151 above described. The ceiling 104 typically would be a plasterboard ceiling in which a suitable hole is cut. A variation of FIG. 15 would be to extend or form the peripheral of outer ring 120 into a flat panel having a dimension of 2 ft. by 2 ft. that would fit in and be held by a grid that holds a conventional ceiling panel.
[0059] Referring to FIG. 17 , an air moving device is fitted with an inlet grill 113 , a light bulb style threaded male end 114 for threading into a light bulb socket, and a light bulb socket 115 . The inlet grill 113 includes a plurality of circumferentially spaced grill fins 116 that attach to the first end of the housing 13 . The grill fins 116 are separated by air intake slots 117 , and extend axially outwardly from the first end 17 and curve radially inwardly to a flat circular mounting plate 118 that is substantially parallel with and spaced axially from the first end 17 . Threaded male end 114 is mounted on and extends upwardly from the mounting plate 118 . The socket 115 is mounted inside the housing 13 in a downwardly opening fashion so that light from a bulb 119 threaded into the socket 115 is directed downwards.
[0060] Referring now to FIG. 18 , there is shown a tent having an inclined top 132 extending down from an apex and connected at the lower end to a vertical side wall 131 and terminating above a floor 133 to provide a side opening 134 so that the tent is an open sided room. The air moving device 12 is mounted below the top apex and directs the air in the room downwardly in a columnar pattern to the floor and along the floor and then back with some air passing in and out the side openings 134 along the floor 133 . For wide tents, the air will pass up before it reaches the side walls.
[0061] The air moving device and system herein described has relatively low electrical power requirement. A typical fan motor is 35 watts at 1600 rpm for an impeller of 8.5″ that will effectively move the air from the ceiling to the floor in a room having a ceiling height of 30 ft. Another example is 75 watts with an impeller diameter 8.5″ at 2300 rpm in a room having a ceiling height of 70 ft.
[0062] Referring now to FIG. 19 , there is shown a shipping container 161 having an air moving device 12 disposed horizontally in the lower left end. The device 12 directs the air horizontally along the bottom wall or floor, up the opposite side wall and across the top wall to exit an outlet duct 162 above and spaced from the device 12 of the air moving device. The device 12 will penetrate the air and promote flushing and circulation of the air space. The device 12 may be mounted to direct the air generally horizontally or up or down at an angle to the true horizontal. This arrangement may be provided in other air spaces such as a trailer truck, room or the like.
[0063] It is understood that the stator 46 and housing 13 could be made as a single unit. It is also understood that the housing 13 may be made in two sections as for example a tubular section of a selected length may be added to the end of a truncated devices as shown in FIG. 14 .
[0064] Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.
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Air moving device includes a housing, an impeller in the housing for generating a downward air flow, and vanes in the housing in close proximity to and a selected distance below the impeller to straighten the air flow. The device produces an air flow that substantially remains in a column over a substantial distance. The method includes producing an air flow that substantially remains in a column over a substantial distance and directing the air flow from the ceiling towards the floor to provide temperature destratification of the air in an enclosed space. The method also includes directing warm air from the ceiling to the floor and storing heat in the floor, apparatus on the floor and ground under the floor. The stored heat is released when the ceiling is cooler than the floor.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] The present application is a Divisional application of application Ser. No. 12/644,370, filed Dec. 22, 2009; which claims priority under 35 U.S.C. §119 of Japanese Patent Application Nos. 2008-329416, filed on Dec. 25, 2008, and 2009-267530, filed on Nov. 25, 2009, in the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a cleaning control apparatus and a substrate processing apparatus capable of cleaning inside thereof. More particularly, the present invention relates to a cleaning control apparatus and a substrate processing apparatus capable of cleaning inside thereof by supplying a cleaning gas into a process chamber and a gas supply system thereof to remove deposition substances attached to an inside thereof after forming a film on a substrate.
[0004] 2. Description of the Prior Art
[0005] In a conventional substrate processing apparatus, when a process gas is supplied, the process gas is distributed not only to the surface of a substrate but also to other parts (for example, the inside of a process chamber), and thus unnecessary films may be accumulated and deposited as attached substances. Such attached substances may include impurities harmful for a substrate processing process, and thus, substrates may be contaminated due to the attached substances.
[0006] Therefore, so as to prevent or suppress such a problem, in addition to the supply of a process gas to the process chamber, a cleaning gas is also supplied to the inside of the process chamber (particularly, parts where it is expected that substances are attached) so as to remove substances attached to the inside of the process chamber by converting the substances into harmless gas and then discharging the harmless gas. That is, self-cleaning is performed (for example, refer to Patent Document 1).
PATENT DOCUMENT 1
[0000]
Japanese Patent No. 3985899
[0008] However, since at least a reaction tube configured to place a substrate therein and a process gas supply nozzle configured to supply a process gas to the reaction tube are disposed in the process chamber, different films may be deposited on the inside (inner wall or other parts) of the reaction tube and the inner wall of the process gas supply nozzle according to a method used to supply a process gas to the inside of the process chamber.
[0009] Exhaust resistance is caused according to the length of the gas supply nozzle or the shape of a gas supply hole, and if the exhaust resistance is high, the inside pressure of the gas supply nozzle becomes higher than the inside pressure of the reaction tube. In this case, generally, since the reaction rate of a process gas increases as pressure increases, the thickness of a film deposited on the inner wall of the gas supply nozzle becomes greater than the thickness of a film deposited on the inside of the reaction tube. Moreover, according to the kind of chemical reaction, the properties of films such as a crystalline structure may be changed.
[0010] By using a silicon source and a nitriding source as process gases, a silicon nitride film can be formed on the surface of a substrate.
[0011] In this case, to prevent generation of a reaction byproduct, the process gases are supplied to a process chamber via separate gas supply nozzles. At this time, a silicon film may be formed, due to decomposition of the silicon source, on the inner wall of a first nozzle through which the silicon source is supplied, although formation of a film caused by decomposition of the nitriding source is not observed at the inner wall of a second nozzle through which the nitriding source is supplied. In addition, a silicon nitride film is formed on the inside of a reaction tube as an attached substance. That is, different films may be formed on the inside of the reaction tube and the inner wall of the gas supply nozzle.
[0012] In the case where films having different qualities and thicknesses are formed on the inside of the reaction tube and the inner wall of the gas supply nozzle, if a cleaning process is performed under normal conditions, there may arise disadvantages such as an increase of cleaning time, generation of contaminants, and damages on the reaction tube and the gas supply nozzle. Moreover, if a cleaning process is performed under normal conditions, the inner wall of the gas supply nozzle may be etched more rapidly than the inside of the reaction tube.
SUMMARY OF THE INVENTION
[0013] An object of the present invention is to provide a method of manufacturing a semiconductor device, a cleaning method, and a cleaning control apparatus that are designed to perform a cleaning process efficiently on the inside of a process chamber while reducing generation of contaminants and damages on a reaction tube and a gas supply nozzle.
[0014] According to an aspect of the present invention, there is provided a substrate processing apparatus comprising: a process chamber accommodating a substrate; a first gas introducing part configured to supply a first source gas and a cleaning gas into the process chamber, the first source gas comprising at least one of a plurality of elements; a second gas introducing part configured to supply a first second gas into the process chamber, the second source gas comprising at least one of the plurality of elements other than those of the first source gas; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, the third gas introducing part being configured to supply the cleaning gas into the process chamber; an exhaust unit configured to exhaust an atmosphere inside the process chamber; and a controller configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part and the exhaust unit to perform, after depositing a film on the substrate by supplying the first source gas and the second source gas into the process chamber: a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying the cleaning gas to the first gas introducing part wherein a cleaning condition is set according to an accumulated supply time of the first source gas supplied into the process chamber through the first gas introducing part; and a second cleaning process so as to remove a second deposition substance attached to an inside of the process chamber and having a different chemical composition from that of the first deposition substance by supplying the cleaning gas into the process chamber through the third gas introducing part wherein the cleaning condition is set according to an accumulated thickness of the film formed on the substrate.
[0015] According to another aspect of the present invention, there is provided a substrate processing apparatus comprising: a process chamber accommodating a substrate; a first gas introducing part configured to supply a first source gas and a cleaning gas into the process chamber, the first source gas comprising at least one of a plurality of elements; a second gas introducing part configured to supply a first second gas into the process chamber, the second source gas comprising at least one of the plurality of elements other than those of the first source gas; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, the third gas introducing part being configured to supply the cleaning gas into the process chamber; an exhaust unit configured to exhaust an atmosphere inside the process chamber; and a controller configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part and the exhaust unit to intermittently supply the cleaning gas into the process chamber through third gas introducing part with an inside pressure of the process chamber set at a first pressure, and to continuously supply the cleaning gas into the process chamber through third gas introducing part with the inside pressure set at a second pressure lower than the first pressure after depositing a film on the substrate by supplying the first source gas and the second source gas.
[0016] According to another aspect of the present invention, there is provided a cleaning control apparatus for a silicon nitride film forming apparatus configured to form a silicon nitride film on a substrate accommodated in the process chamber by alternately supplying a silicon-containing gas through a silicon-containing gas supply system and a nitriding source gas through a nitriding source gas supply system, the cleaning control apparatus comprising: a first cleaning request signal output unit comprising a first memory unit configured to store an accumulated amount of molecules of the silicon-containing gas supplied into the process chamber through the silicon-containing gas supply system, the first cleaning request signal output unit being configured to output a first cleaning request signal to request a cleaning of the silicon-containing gas supply system when the accumulated amount of the molecules of the silicon-containing gas stored in the first memory unit is equal to or greater than a preset accumulated amount of the molecules of the silicon-containing gas; and a second cleaning request signal output unit comprising a second memory unit configured to store an accumulated amount of molecules of the nitriding source gas supplied into the process chamber through the nitriding source gas supply system, the second cleaning request signal output unit being configured to output a second cleaning request signal to request a cleaning of the nitriding source gas supply system when the accumulated amount of the molecules of the nitriding source gas stored in the second memory unit is equal to or greater than a preset accumulated amount of the molecules of the nitriding source gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic view illustrating a vertical process furnace of a substrate processing apparatus suitable for an embodiment of the present invention.
[0018] FIG. 2 is a sectional view taken from line A-A′ of FIG. 1 .
[0019] FIG. 3 is a flowchart for explaining a film-forming method according to an embodiment of the present invention.
[0020] FIG. 4 is a flowchart for explaining a cleaning method according to an embodiment of the present invention.
[0021] FIG. 5 is a flowchart for explaining a cleaning method according to an embodiment of the present invention.
[0022] FIG. 6 is a flowchart for explaining a cleaning method according to another embodiment of the present invention.
[0023] FIG. 7A and FIG. 7B are views illustrating control units according to an embodiment of the present invention.
[0024] FIG. 8 is a schematic view illustrating a vertical process furnace of a substrate processing apparatus suitable for another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Embodiments of the present invention will be described hereinafter with reference to the attached drawings.
(1) Structure of Substrate Processing Apparatus
[0026] FIG. 1 is a schematic vertical sectional view illustrating a vertical process furnace 202 of a substrate processing apparatus suitable for an embodiment of the present invention. FIG. 2 is a sectional view taken from line A-A′ of FIG. 1 .
[0027] As shown in FIG. 1 , the process furnace 202 includes a heater 207 used as a heating unit (heating mechanism). The heater 207 has a cylindrical shape and is vertically installed in a state where the heater 207 is supported on a heater base (not shown) which is a holding plate.
[0028] Inside the heater 207 , a process tube 203 is installed concentrically with the heater 207 as a reaction tube. The process tube 203 is made of a heat-resistant material such as a quartz (SiO 2 ) or silicon carbide (SiC) and has a cylindrical shape with a closed top side and an opened bottom side. The hollow part of the process tube 203 forms a process chamber 201 and is configured to accommodate substrates such as wafers 200 by using a substrate holder such as a boat 217 (described later) in a manner such that the wafers 200 are horizontally positioned and vertically arranged in multiple stages.
[0029] At the lower side of the process chamber 201 , a first nozzle 233 a and a second nozzle 233 b are installed as a first gas introducing part and a second gas introducing part, and a first gas supply pipe 232 a and a second gas supply pipe 232 b are connected to the first nozzle 233 a and the second nozzle 233 b , respectively. In this way, as gas supply passages for supplying a plurality of kinds of gases (in the current embodiment, two kinds of gases) to the inside of the process chamber 201 , two gas supply pipes are installed. In the structure, the lower side of the process chamber 201 is a region where no wafer 200 is placed, and the lower side of the process chamber 201 is not a heating region.
[0030] At the first gas supply pipe 232 a , a flowrate controller (flowrate control unit) such as a first mass flow controller (MFC) 241 a , and an on-off valve such as a first valve 243 a are sequentially installed from the upstream side of the first gas supply pipe 232 a . In addition, the first nozzle 233 a is connected to the leading end of the first gas supply pipe 232 a . In an arc-shaped space between the inner wall of the process tube 203 constituting the process chamber 201 and wafers 200 , the first nozzle 233 a is installed in a manner such that the first nozzle 233 a extends from the lower side to the upper side along the inner wall of the process tube 203 in a direction in which the wafers 200 are stacked. First gas supply holes 248 a are formed through the lateral surface of the first nozzle 233 a . Along the lower side to the upper side, the first gas supply holes 248 a are formed in a manner that the first gas supply holes 248 a have the same size and are arranged at the same pitch. A first gas supply system is mainly constituted by the first gas supply pipe 232 a , the first MFC 241 a , the first valve 243 a , and the first nozzle 233 a.
[0031] At the second gas supply pipe 232 b , a flowrate controller (flowrate control unit) such as a second MFC 241 b , and an on-off valve such as a second valve 243 b are sequentially installed from the upstream side of the second gas supply pipe 232 b . In addition, the second nozzle 233 b is connected to the leading end of the second gas supply pipe 232 b . In an arc-shaped space between the inner wall of the process tube 203 constituting the process chamber 201 and the wafers 200 , the second nozzle 233 b is installed in a manner such that the second nozzle 233 b extends from the lower side to the upper side along the inner wall of the process tube 203 in a direction in which the wafers 200 are stacked. Second gas supply holes 248 b are formed through the lateral surface of the second nozzle 233 b . Along the lower side to the upper side, the second gas supply holes 248 b are formed in a manner that the second gas supply holes 248 b have the same size and are arranged at the same pitch. A second gas supply system is mainly constituted by the second gas supply pipe 232 b , the second MFC 241 b , the second valve 243 b , and the second nozzle 233 b.
[0032] For example, dichlorosilane (SiH 2 Cl 2 , abbreviation: DCS) gas may be supplied from the first gas supply pipe 232 a to the inside of the process chamber 201 through the first MFC 241 a , the first valve 243 a , and the first nozzle 233 a . At this time, inert gas may be simultaneously supplied to the inside of the first gas supply pipe 232 a . In addition, ammonia (NH 3 ) gas may be supplied from the second gas supply pipe 232 b to the inside of the process chamber 201 through the second MFC 241 b , the second valve 243 b , and the second nozzle 233 b . At this time, inert gas may be simultaneously supplied to the inside of the second nozzle 233 b.
[0033] In addition, at the lower side of the process chamber 201 , a short pipe 301 is installed as a third gas introducing part. A first cleaning gas supply pipe 300 which is a cleaning gas supply passage is connected to the short pipe 301 . Cleaning gas is used for removing substances attached to the inside of the process chamber 201 . At the first cleaning gas supply pipe 300 , a flowrate controller (flowrate control unit) such as a third MFC 302 , and an on-off valve such as a third valve 304 are installed. Cleaning gas is introduced into the first cleaning gas supply pipe 300 for supplying the cleaning gas to the process chamber 201 .
[0034] A second cleaning gas supply pipe 350 , which is a cleaning gas supply passage separate from the first cleaning gas supply pipe 300 , is connected to the first gas supply pipe 232 a . At the second cleaning gas supply pipe 350 , a flowrate controller (flowrate control unit) such as a fourth MFC 352 , and an on-off valve such as a fourth valve 354 are installed. Cleaning gas is introduced into the second cleaning gas supply pipe 350 for supplying the cleaning gas to the process chamber 201 through the first gas supply pipe 232 a.
[0035] In addition, a gas exhaust pipe 231 is installed to exhaust the inside atmosphere of the process chamber 201 . A vacuum exhaust device such a vacuum pump 246 is connected to the downstream side of the gas exhaust pipe 231 opposite to the process tube 203 through a pressure detector such as a pressure sensor 245 and a pressure regulator such as an auto pressure controller (APC) valve 242 . The APC valve 242 is an on-off valve, which can be opened and closed to start and stop vacuum evacuation of the inside of the process chamber 201 and can be adjusted in opened degree for pressure adjustment. While operating the pressure sensor 245 , by controlling the opened degree of the APC valve 242 based on pressure information detected by the pressure sensor 245 , the inside of the process chamber 201 can be vacuum-evacuated to a desired pressure (vacuum degree).
[0036] A seal cap 219 is installed as a furnace port cover capable of hermetically closing the opened bottom side of the process tube 203 . For example, the seal cap 219 is made of a metal such as stainless steel and has a disk shape. On the top surface of the seal cap 219 , an O-ring 220 is installed as a seal member. At a side of the seal cap 219 opposite to the process chamber 201 , a rotary mechanism 267 is installed to rotate a boat 217 (described later) which is a substrate holder. A rotation shaft (not shown) of the rotary mechanism 267 is connected to the boat 217 through the seal cap 219 . The rotary mechanism 267 is configured to rotate wafers 200 by rotating the boat 217 . The seal cap 219 is configured to be vertically moved by an elevating mechanism such as a boat elevator (not shown) which is vertically installed outside the process tube 203 . The boat elevator is configured to move the seal cap 219 vertically for loading/unloading the boat 217 to/from the process chamber 201 .
[0037] The boat 217 is made of a heat-resistant material such as quartz or silicon carbide and is configured to support a plurality of wafers 200 in a state where the wafers 200 are horizontally oriented and arranged in multiple stages with the centers of the wafers 200 being aligned with each other. In addition, at the lower part of the boat 217 , an insulating member 218 made of a heat-resistant material such as quartz or silicon carbide is installed so as to prevent heat transfer from the heater 207 to the seal cap 219 . The insulating member 218 may include a plurality of insulating plates made of a heat-resistant material such as quartz or silicon carbide, and an insulating plate holder configured to support the insulating plates in a state where the insulating plates are horizontally oriented and arranged in multiple stages. Inside the process tube 203 , a temperature sensor 263 is installed as a temperature detector, and by controlling power supplied to the heater 207 based on temperature information detected by the temperature sensor 263 , desired temperature distribution can be attained at the inside of the process chamber 201 . Like the first nozzle 233 a and the second nozzle 233 b , the temperature sensor 263 is installed along the inner wall of the process tube 203 .
[0038] A controller 280 which is a control unit (control device) is connected to the first to fourth MFC 241 a , 241 b , 302 , and 352 , the first to fourth valves 243 a , 243 b , 304 , and 305 , the pressure sensor 245 , the APC valve 242 , the heater 207 , the temperature sensor 263 , the vacuum pump 246 , the rotary mechanism 267 , and so on.
[0039] The controller 280 is used to control, for example, flowrates of the first to fourth MFC 241 a , 241 b , 302 , and 352 ; opening/closing operations of the first to fourth valves 243 a , 243 b , 304 , and 305 ; opening/closing operations of the APC valve 242 and pressure adjusting operations of the APC valve 242 based on the pressure sensor 245 ; the temperature of the heater 207 based on the temperature sensor 263 ; starting/stopping operations of the vacuum pump 246 ; and the rotation speed of the rotary mechanism 267 .
(2) Method of Forming Silicon Nitride Film
[0040] Next, as an example of a film-forming method for a semiconductor device manufacturing process using the above-described substrate processing apparatus, an exemplary method of forming a silicon nitride (SiN) film containing stoichiometrically excessive silicon (Si) with respect to nitrogen (N) (i.e., a silicon-rich silicon nitride film) by using dichlorosilane (DCS) and ammonia (NH 3 ) will now be described according to an embodiment. In addition, the present invention can be applied to any kind of film without being limited to a silicon-rich silicon nitride film so long as the film is formed by using two or more kinds of gases.
[0041] In the following description, components of the substrate processing apparatus are controlled by the controller 280 .
[0042] In the current embodiment, a film is formed by using a method similar to but not identical to an atomic layer deposition (ALD) method. In an ALD method, process gases which provide at least two source materials for forming a film are supplied to a substrate in turns under predetermined film forming conditions (temperature, time, etc.), so as to allow the process gases to be adsorbed on the substrate on an atomic layer basis for forming a film by surface reaction. At this time, the thickness of the film can be controlled by adjusting the number of process gas supply cycles (for example, if the film forming rate is 1 Å/cycle and it is intended to form a 20-Å film, the process is repeated 20 cycles).
[0043] That is, in the film-forming method of the current embodiment, a process of supplying DCS to a wafer 200 under conditions where chemical vapor deposition (CVD) reaction is caused, and a process of supplying NH 3 to the wafer 200 under a non-plasma condition and other predetermined conditions are repeated in turns so as to form a silicon-rich silicon nitride (SiN) film. In the current embodiment, a process (Step 1 ) of supplying DCS to a wafer 200 , a process (Step 2 ) of removing the DCS from the wafer 200 , a process (Step 3 ) of supplying NH 3 to the wafer 200 , and a process (Step 4 ) of removing the NH 3 from the wafer 200 are set to one cycle, and the cycle is repeated a plurality of times to form a silicon-rich silicon nitride (SiN) film. In the process (Step 1 ) of supplying DCS to a wafer 200 , a silicon film having several or less atomic layers (1/n to several atomic layers) is formed on the wafer 200 . At this time, an excessive amount of silicon (Si) is supplied. Furthermore, in the process (Step 3 ) of supplying NH 3 to the wafer 200 , the silicon film having several or less atomic layers and formed on the wafer 200 is thermally nitrided. At this time, the silicon film is nitrided by NH 3 in a non-saturated condition. That is, the silicon film is not completely nitrided, and thus Si—N bonds are not fully made. In this way, nitriding of silicon (Si) is suppressed, and thus silicon (Si) becomes surplus. At this time, to obtain a condition where nitriding of the silicon film is not saturated, it is preferable that at least one of the supply flowrate of NH 3 , the supply time of NH 3 , and the inside pressure of the process chamber 201 be adjusted to be different from a condition where the nitriding of the silicon film is saturated. That is, as compared with a condition where nitriding of the silicon film is saturated, the supply flowrate of NH 3 is reduced, the supply time of NH 3 is shortened, or the inside pressure of the process chamber 201 is reduced. For example, a small amount of NH 3 is supplied as compared with the amount of NH 3 necessary for forming a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition. As described above, the supply flowrate of silicon (Si) is controlled in the process of forming a silicon film having several or less atomic layers on a wafer 200 by using a CVD method, and the nitriding degree of silicon (Si) is controlled in the process of thermally nitriding the silicon film with NH 3 . The processes are alternately repeated to form a silicon-rich silicon nitride (SiN) film while controlling the Si/N composition ratio of the silicon nitride (SiN).
[0044] Hereinafter, the film-forming method of the current embodiment will be described in detail with reference to FIG. 3 .
[0045] After a plurality of wafers 200 are charged into the boat 217 (wafer charging), as shown in FIG. 1 , the boat 217 in which the plurality of wafers 200 are charged is lifted and loaded into the process chamber 201 by the boat elevator (not shown) (boat loading). In this state, the bottom side of the process tube 203 is sealed by the seal cap 219 with the O-ring 220 b being disposed therebetween.
[0046] The inside of the process chamber 201 is vacuum-evacuated to a desired pressure (vacuum degree) by using the vacuum pump 246 . At this time, the pressure inside the process chamber 201 is measured by the pressure sensor 245 , and based on the measured pressure, the APC valve 242 is feedback-controlled (pressure adjustment). In addition, the inside of the process chamber 201 is heated to a desired temperature by using the heater 207 . At this time, to obtain desired temperature distribution inside the process chamber 201 , power to the heater 207 is feedback-controlled based on temperature information measured by the temperature sensor 263 (temperature adjustment). Next, the boat 217 is rotated by the rotary mechanism 267 to rotate the wafers 200 . Thereafter, the following four steps are sequentially performed.
[0047] (Step 1 )
[0048] The first valve 243 a of the first gas supply pipe 232 a is opened to allow DCS to flow through the first gas supply pipe 232 a . At this time, inert gas may be allowed to flow through the first gas supply pipe 232 a . The flowrate of DCS flowing through the first gas supply pipe 232 a is controlled by the first MFC 241 a , and the DCS is mixed with flowrate-controlled inert gas. Then, the mixture is supplied to the inside of the process chamber 201 through the first gas supply holes 248 a of the first nozzle 233 a and is discharged through the gas exhaust pipe 231 . At this time, the APC valve 242 is properly controlled to keep the inside of the process chamber 201 at a pressure of 133 Pa to 1333 Pa, for example, 133 Pa. The first MFC 241 a is used to adjust the flowrate of DCS in the range from 0.1 slm to 10 slm, for example, 0.5 slm. The wafers 200 are exposed to DCS, for example, for 1 second to 180 seconds. At this time, the heater 207 is controlled to allow thermal decomposition of DCS for inducing CVD reaction. That is, the heater 207 is controlled to heat the wafers 200 to a temperature of 550° C. to 700° C., for example, 630° C. By supplying DCS to the inside of the process chamber 201 under the above-described conditions, silicon (Si) films each including several or less atomic layers (that is, 1/n atomic layer to several atomic layers) are formed on the wafers 200 (deposition of CVD-Si film). For example, silicon films each including a half atomic layer (half layer) or a mono atomic layer (mono layer) may be formed. In this way, silicon (Si) is excessively supplied.
[0049] (Step 2 )
[0050] After the silicon films each including several or less atomic layers are formed, the first valve 243 a of the first gas supply pipe 232 a is closed so as to interrupt supply of DCS. At this time, in a state where the APC valve 242 of the gas exhaust pipe 231 is opened, the inside of the process chamber 201 is vacuum-exhausted to 10 Pa or less by using the vacuum pump 246 to remove remaining DCS from the inside of the process chamber 201 . Along with this, if inert gas such as N 2 is supplied to the inside of the process chamber 201 , the remaining DCS may be removed more efficiently (remaining gas removal).
[0051] (Step 3 )
[0052] The second valve 243 b of the second gas supply pipe 232 b is opened to allow NH 3 to flow through the second gas supply pipe 232 b . At this time, inert gas may be allowed to flow through the second gas supply pipe 232 b . The flowrate of NH 3 flowing through the second gas supply pipe 232 b is controlled by the second MFC 241 b , and the NH 3 is mixed with flowrate-controlled inert gas. Then, the mixture is supplied to the inside of the process chamber 201 through the second gas supply holes 248 b of the second nozzle 233 b and is discharged through the gas exhaust pipe 231 . As described above, NH 3 is supplied to the inside of the process chamber 201 in a state where the NH 3 is not activated by plasma.
[0053] In Step 3 , the inside conditions of the process chamber 201 are adjusted so that the silicon films are nitrided under conditions where the nitriding reaction of the silicon film by the NH 3 is not saturated. That is, the supply amount of NH 3 is adjusted to be less than an amount necessary for nitriding the silicon films to form silicon nitride (Si 3 N 4 ) films each having a stoichiometric composition. In addition, at this time, the APC valve 242 is properly adjusted to keep the inside of the process chamber 201 at a pressure of 133 Pa to 1333 Pa, for example, 865 Pa. The second MFC 241 b is controlled to supply NH 3 at a flowrate of 0.1 slm to 10 slm, for example, 1 slm. The wafers 200 are exposed to NH 3 for 1 second to 180 seconds. At this time, the heater 207 is controlled so as to keep the wafers 200 in the same temperature range of 550° C. to 700° C., for example, 630° C., like the case of supplying DCS in Step 1 . In this way, NH 3 is supplied to the inside of the process chamber 201 in a non-plasma condition, so as to thermally nitride the silicon films each including several or less atomic layers and formed on the wafers 200 (thermal nitriding of CVD-Si film). At this time, since silicon is excessive due to the restrained nitriding of silicon (Si), silicon-rich silicon nitride films can be formed.
[0054] If it is assumed that all DCS and NH 3 supplied to the inside of the process chamber 201 are used to form a silicon nitride film, a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition can be formed on a wafer 200 by supplying DCS which is a silicon-containing substance and NH 3 which is a nitrogen-containing substance to the inside of the process chamber 201 at a ratio of 3:4. In the current embodiment, however, the supply amount of NH 3 is less than the amount necessary for thermally nitriding a silicon film to form a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition. That is, the supply amount of NH 3 is restricted so as not to saturate nitriding reaction of the silicon film. In this way, the amount of nitrogen is adjusted to be insufficient for forming a silicon nitride (Si 3 N 4 ) film having a stoichiometric composition, so that a silicon-rich silicon nitride film can be formed on the wafer 200 .
[0055] Practically, the composition ratio of silicon/nitrogen of a silicon nitride film is varied not only by the supply amount of NH 3 , but also by other conditions in Step 3 , such as difference of reactiveness caused by the inside pressure of the process chamber 201 , difference of reactiveness caused by the temperature of a wafer 200 , the supply flowrate of NH 3 , and the supply time of NH 3 (that is, reaction time). In addition, the composition ratio of silicon and nitrogen of a silicon nitride film is also varied by conditions in Step 1 , such as the pressure inside the process chamber 201 , the temperature of a wafer 200 , the supply flowrate of DCS, and the supply time of DCS. That is, controlling of the balance between the supply of silicon (Si) in Step 1 and the supply of nitrogen (N) in Step 3 is important for controlling the composition ratio of silicon and nitrogen (Si/N ratio) of a silicon nitride film. In the current embodiment, the pressure inside the process chamber 201 , the temperature of a wafer 200 , the supply flowrate of gas, and the supply time of gas are properly controlled within the above-described mentioned ranges, so as to control the composition ratio of silicon/nitrogen of a silicon nitride film. If the amount of silicon (Si) supplied in Step 1 is concerned as a reference (is fixed to a predetermined value), the Si/N ratio is most dependent on the supply flowrate of NH 3 , the supply time of NH 3 , and the pressure inside the process chamber 201 among conditions in Step 3 . Therefore, in Step 3 , it is preferable that at least one of the supply flowrate of NH 3 , the supply time of NH 3 , and the pressure inside the process chamber 201 be different from conditions where the nitriding reaction of a silicon film is saturated. Specifically, the supply flowrate of NH 3 , the supply time of NH 3 , or the pressure inside the process chamber 201 may be reduced as compared with a condition where the nitriding reaction of a silicon film is saturated.
[0056] (Step 4 )
[0057] After the silicon films each including several or less atomic layers are thermally nitrided, the second valve 243 b of the second gas supply pipe 232 b is closed to interrupt supply of NH 3 . At this time, in a state where the APC valve 242 of the gas exhaust pipe 231 is opened, the inside of the process chamber 201 is exhausted to a pressure of 10 Pa or less to remove remaining NH 3 from the inside of the process chamber 201 . Along with this, if inert gas such as N 2 is supplied to the inside of the process chamber 201 , remaining NH 3 can be removed more efficiently (remaining gas removal).
[0058] By setting the above-mentioned Steps 1 to 4 to one cycle, and repeating this cycle a plurality of times, silicon-rich silicon nitride films can be formed on the wafers 200 to a predetermined thickness.
[0059] After silicon-rich silicon nitride films are formed to a predetermined thickness, the inside of the process chamber 201 is purged by supplying inert gas such as N 2 to the inside of the process chamber 201 and exhausting the inert gas from the inside of the process chamber 201 (purge). By this, the inside atmosphere of the process chamber 201 is replaced with inert gas, and the inside pressure of the process chamber 201 is returned to atmospheric pressure (returning to atmospheric pressure).
[0060] Thereafter, the seal cap 219 is moved downward by the boat elevator (not shown) so as to open the bottom side of the process tube 203 and unload the processed wafers 200 from the inside of the process tube 203 through the bottom side of the process tube 203 in a state where the processed wafers 200 are held in the boat 217 (boat unloading). Then, the processed wafers 200 are discharged from the boat 217 (wafer discharging).
[0061] Although DCS is used as a silicon source in the above description, the present invention is not limited thereto. For example, another substance such as trichlorosilane (SiHCl 3 , abbreviation: TCS), hexachlorosilane (Si 2 Cl 6 , abbreviation: HCD), monosilane (SiH 4 ), and disilane (Si 2 H 6 ) may be used.
(3) Cleaning Method
[0062] After a process of forming a silicon-rich silicon nitride is performed predetermined times, a cleaning process is performed on the process chamber 201 by using a cleaning gas. In the current embodiment, for example, chlorine trifluoride (ClF 3 ) is used as a cleaning gas.
[0063] The first nozzle 233 a and the inside of the process tube 203 (for example, the inner wall of the process tube 203 , the outer walls of the first nozzle 233 a and the second nozzle 233 b , and the boat 217 ) are cleaned under conditions optimal for the respective parts.
[0064] <Method of Cleaning Inner Wall of First Nozzle>
[0065] First, cleaning of the inner wall of the first nozzle 233 a will be explained ( FIG. 4 ). Cleaning of the inner wall of the first nozzle 233 a is performed under a pressure lower than a pressure at which the inside of the process tube 203 is cleaned.
[0066] (Step 11 )
[0067] In Step 11 , first, the APC valve 242 is opened to exhaust the inside of the process chamber 201 . At this time, the fourth valve 354 and the first valve 243 a are closed.
[0068] (Step 12 )
[0069] If the inside of the process chamber 201 is sufficiently exhausted, the fourth valve 354 is opened to supply ClF 3 gas to the first nozzle 233 a while controlling the flowrate of the ClF 3 gas by using the fourth MFC 352 (Step 12 ). At this time, the flowrate of the ClF 3 gas is set to from 0.1 slm to 0.4 slm, for example, 0.1 slm. In addition, inert gas such as N 2 gas is simultaneously supplied, for example, at a flowrate of 0.4 slm, and the ClF 3 concentration of the inside of the first nozzle 233 a is set to from 20% to 50%, for example, 20%. In the case where the ClF 3 concentration of the inside of the first nozzle 233 a is kept higher than 20%, the flowrate of N 2 gas simultaneously supplied through a part such as the second nozzle 233 b is increased so as to keep the concentration of ClF 3 equal to or lower than 20% when the ClF 3 is exhausted from the inside of the process chamber 201 .
[0070] Furthermore, in a state where the APC valve 242 is opened, the controller 280 adjusts pressure to a predetermined level. Preferably, the pressure is adjusted to a constant level between 10 Pa to 400 Pa, for example, 66.7 Pa (0.5 Torr). By this, a silicon film (unnecessary silicon film to be removed), which is accumulated on the inner wall of the first nozzle 233 a during the above-described film-forming process, is brought into reaction with supplied ClF 3 gas.
[0071] (Step 13 )
[0072] After ClF 3 gas is supplied to the first nozzle 233 a for a predetermined time, the first valve 243 a is closed, and the inside of the process chamber 201 is exhausted (Step 13 ). In addition, while ClF 3 is supplied through the first nozzle 233 a , inert gas such as N 2 gas may be supplied to the inside of the process chamber 201 through the second nozzle 233 b and the short pipe 301 . By supplying inert gas such as N 2 gas, reverse flows of ClF 3 gas from the inside of the process chamber 201 to the second nozzle 233 b and the short pipe 301 can be prevented.
[0073] <Method of Cleaning Inside of Process Tube>
[0074] Next, a method of cleaning the inside of the process tube 203 will be explained. The following two steps are mainly performed ( FIG. 5 ).
[0075] (Step 21 )
[0076] In Step 21 , the process chamber 201 is filled with ClF 3 gas. First, the temperature of the heater 207 is set to from 400° C. to 420° C., for example, 400° C. Then, in a state where the inside of the process chamber 201 is exhausted by opening the APC valve 242 (the fourth valve 354 is closed), the third valve 304 is opened to supply ClF 3 to the first cleaning gas supply pipe 300 and fully fill the inside of the process chamber 201 with the ClF 3 . For example, the flowrate of ClF 3 supplied through the short pipe 301 is set to 0.5 slm. Since parts such as an exhaust pipe may be corroded if the concentration of ClF 3 is high, the concentration of ClF 3 is set to, for example, 20%. To control the inside pressure of the process chamber 201 , the APC valve 242 is opened, and the inside pressure of the process chamber 201 is adjusted to a predetermined level. Preferably, the inside pressure of the process chamber 201 is adjusted to a constant level between 400 Pa to 1000 Pa, for example, 931 Pa (7 Torr).
[0077] By supplying ClF 3 to the inside of the process chamber 201 through the short pipe 301 as described above, the inside of the process chamber 201 can be cleaned without involving the first nozzle 233 a.
[0078] In addition, inert gas such as N 2 gas may be supplied through the first nozzle 233 a and the second nozzle 233 b . By supplying N 2 gas, reverse flows of ClF 3 gas from the inside of the process chamber 201 to the first nozzle 233 a and the second nozzle 233 b can be prevented. The flowrate of N 2 gas supplied through the first nozzle 233 a and the second nozzle 233 b may be 0.8 slm, for example. Furthermore, inert gas such as N 2 gas may be supplied through the rotation shaft (not shown) of the rotary mechanism 267 , for example, at a flowrate of 0.3 slm.
[0079] Then, if a predetermined time (for example, 85 seconds) elapses after the third valve 304 is opened, Step 22 is performed.
[0080] (Step 22 )
[0081] In Step 22 , gas filled in the process chamber 201 is exhausted. A silicon nitride film (unnecessary silicon nitride film to be removed) accumulated in the process chamber 201 during the film-forming process is brought into reaction with ClF 3 supplied in Step 21 , and ClF 3 gas (including ClF 3 gas not participated in reaction) and N 2 gas are mainly filled in the process chamber 201 . Therefore, such gases are exhausted from the process chamber 201 .
[0082] In detail, the APC valve 242 is opened so as to exhaust gas filled in the process chamber 201 at a time through the gas exhaust pipe 231 .
[0083] Then, if a predetermined time (for example, 10 seconds) after the APC valve 242 is opened, Step 22 is stopped. Thereafter, Step 21 and Step 22 are set as a cycle, and the cycle is repeated predetermined times. In this way, cleaning of the inside of the process tube 203 is completed.
[0084] Furthermore, in Step 22 , at the same time with vacuum evacuation, N 2 purge may be performed by supplying inert gas such as N 2 through the first nozzle 233 a , the second nozzle 233 b , and the short pipe 301 ; or in Step 22 , vacuum evacuation and N 2 purge may be alternately repeated predetermined times.
[0085] By repeating Step 21 and Step 22 (one cycle) predetermined times, the inside of the process tube 203 is cleaned. As described above, exhaustion of gas that does not contribute to cleaning, and supply of new ClF 3 gas are repeated, so that cleaning gas can be effectively reacted with a silicon nitride accumulated in the inside of the process tube 203 .
[0086] Either the cleaning of the inner wall of the first nozzle 233 a or the cleaning of the inside of the process tube 203 may first be performed, and then the other may be performed; however, it is preferable that the cleaning of the inner wall of the first nozzle 233 a be first performed. In the case where the cleaning of the inner wall of the first nozzle 233 a is first performed, ClF 3 gas that passes through the first nozzle 233 a with reaction is supplied to the inside of the process tube 203 , and the ClF 3 gas reacts with a silicon nitride film accumulated in the inside (inner wall, etc.) of the process tube 203 , so that the silicon nitride film can be removed. Therefore, if the cleaning of the inside of the process tube 203 is performed after the cleaning of the inner wall of the first nozzle 233 a , time necessary for cleaning the inside of the process tube 203 can be reduced. That is, by cleaning the inner wall of the first nozzle 233 a first, a high etching rate can be obtained, and thus throughput can be improved.
[0087] In addition, since a silicon nitride film is attached to almost all the region of the inside of the process tube 203 , the cleaning cycle may be determined according to the thickness of the silicon nitride film accumulated in the process tube 203 (corresponding to the amount of deposition on a wafer), and the cleaning cycle may be performed each time after the film-forming process is repeated a predetermined number of times. Therefore, cleaning conditions of the inside of the process tube 203 such as the inside pressure of the process tube 203 or the supply flowrate of cleaning gas may be determined according to the actual amount of deposition. The amount of deposition on wafers can be calculated by monitoring the supply flowrate of NH 3 .
[0088] Meanwhile, the thickness of a silicon film accumulated on the inner wall of the first nozzle 233 a is varied according to film-forming conditions such as substrate temperature, DCS supply time, and DCS supply amount. Therefore, cleaning conditions of the inner wall of the first nozzle 233 a such as the inside pressure of the first nozzle 233 a and the supply flowrate of cleaning gas are determined according to film-forming conditions such as DCS supply time and DCS supply flowrate. The cleaning cycle of the inside of the first nozzle 233 a is determined according to film-forming conditions such as DCS supply time and DCS supply flowrate. In addition, when DCS is supplied as a process gas, the thickness of a silicon film accumulated on the inner wall of the first nozzle 233 a may be proportional to the supply amount of silicon molecules.
[0089] As described above, for removing the thickness of a film by a desired amount, that is, for removing the accumulated thickness of a film by a desired amount, cleaning conditions of the inside of the process tube 203 are adjusted according to the number of cycles of the silicon nitride film forming process, and cleaning conditions of the inner wall of the first nozzle 233 a are adjusted according to film-forming conditions such as DCS supply time and DCS supply flowrate.
[0090] In addition, preferably, the cleaning conditions and cleaning timing of the insides of the first nozzle 233 a and the process tube 203 may be determined and controlled by control units 500 a and 500 b as shown in FIG. 7A and FIG. 7B .
[0091] FIG. 7A illustrates the control unit 500 a configured to control cleaning conditions and timing of the first nozzle 233 a by monitoring film-forming conditions when DCS is supplied. That is, each time a film-forming process is performed, the supply amount of DCS is monitored by a monitoring unit 510 a which is configured to monitor the first MFC 241 a which is a flowrate controller (flowrate control unit) or to monitor a process recipe (film-forming process conditions), and the monitored supply amount of DCS is added by a counter such as an adding unit 520 a . The added DCS supply amount (the accumulated amount of DCS) is stored in a memory device such as a memory unit 530 a . The accumulated amount of DCS is compared with a predetermined threshold value by a comparison unit 540 a . The threshold value is preset at the comparison unit 540 a.
[0092] If the accumulated amount of DCS reaches the threshold value, the comparison unit 540 a informs a signal output unit 550 a of the event, and then the signal output unit 550 a sends at least one of a cleaning condition setting signal and a cleaning start signal to the controller 280 .
[0093] Similarly, FIG. 7B illustrates the control unit 500 b configured to control cleaning conditions and timing of the second nozzle 233 b by monitoring film-forming conditions when NH 3 is supplied through the second nozzle 233 b . That is, each time a film-forming process is performed, the supply amount of NH 3 is monitored by a monitoring unit 510 b which is configured to monitor the second MFC 241 b which is a flowrate controller (flowrate control unit) or to monitor a process recipe (film-forming process conditions), and the monitored supply amount of NH 3 is added by a counter such as an adding unit 520 b . The added NH 3 supply amount (the accumulated amount of NH 3 ) is stored in a memory device such as a memory unit 530 b . The accumulated amount of NH 3 is compared with a predetermined threshold value by a comparison unit 540 b . The threshold value is preset at the comparison unit 540 b.
[0094] If the accumulated amount of NH 3 reaches the threshold value, the comparison unit 540 b informs a signal output unit 550 b of the event, and then the signal output unit 550 b sends at least one of a cleaning condition setting signal and a cleaning start signal to the controller 280 .
[0095] In addition, after considering things related to cleaning quality, such as whether a desired film is uniformly removed (without over-etching of quartz), whether corrosion occurs, whether contaminants generate, and whether remaining gas affects a film-forming process, cleaning conditions are timing are determined to increase the etching rate (that is, throughput).
[0096] Furthermore, when the inside of the process tube 203 is cleaned, inert gas is continuously supplied to the first nozzle 233 a and the second nozzle 233 b.
[0097] Furthermore, cleaning of the inside of the process tube 203 may be overlapped with cleaning of the inner wall of the first nozzle 233 a at least partially. In this case, if the cleaning of the inner wall of the first nozzle 233 a is performed at the same pressure as a pressure at which the cleaning of the inside of the process tube 203 is performed, the first nozzle 233 a may be damaged and broken. On other hand, if the cleaning of the inside of the process tube 203 is performed at the same pressure as a pressure at which the cleaning of the inner wall of the first nozzle 233 a is performed, the cleaning time may be increased because the pressure is too low. For this reason, although the cleaning of the inner wall of the first nozzle 233 a is performed at the same pressure as a pressure at which the cleaning of the inside of the process tube 203 is performed, a low-concentration cleaning gas is supplied to the inner wall of the first nozzle 233 a . Since a cleaning gas is supplied only through the short pipe 301 during a cleaning process of the inside of the process tube 203 and a cleaning gas is supplied only to the first nozzle 233 a during a cleaning process of the inner wall of the first nozzle 233 a , flowrate tuning is necessary for performing the two cleaning processes at the same time.
[0098] In addition, if the amount of silicon attached to the inner wall of the first nozzle 233 a is large, since it is difficult to remove the silicon from the first nozzle 233 a , the pressure of a cleaning process is increased. However, if the pressure is increased too much, although the cleaning process can be completed more rapidly owing to an increased etching rate, the first nozzle 233 a may be devitrified due to generation of heat. If the first nozzle 233 a is damaged in this way, it may be necessary to replace the first nozzle 233 a . In addition, since the inside of the first nozzle 233 a is narrow and long, by rapidly making the inside pressure of the first nozzle 233 a uniform, the rate of etching can be made uniform in the vertical direction.
[0099] According to the current embodiment, one or more of the following effects can be attained.
[0100] The inside of the process tube 203 , where a silicon nitride is accumulated, and the inner wall of the first nozzle 233 a , where a silicon source such as DCS is supplied and a silicon film is accumulated, are cleaned under conditions optimized for the respective parts, so that cleaning can be efficiently performed with less contamination, damage of the process tube 203 , and damage of the first nozzle 233 a.
[0101] That is, cleaning can be thoroughly performed with less cleaning time and good gas consumption efficiency without a remaining film.
[0102] In addition, generation of contamination caused by excessive etching conditions can reduced; operational costs can be reduced because the process tube 203 and the first nozzle 233 a can be less damaged; and maintenance time can be reduced.
[0103] When a silicon nitride film attached to the inside of the process tube 203 is cleaned, by filling a high-concentration cleaning gas in the entire inside of the process tube 203 and increasing the inside pressure of the process tube 203 , particularly, the upper part of the process chamber 201 can be less affected by gas flow distribution, and the cleaning process can be completed within a shorter time.
[0104] When a silicon nitride film attached to the inside of the process tube 203 is cleaned, by alternately repeating supply of a cleaning gas and exhaustion of the cleaning gas (cyclic supply), stagnant gas can be exhausted by distribution of gas flows and thus be replaced with a cleaning gas. That is, exhaustion of gas that has reacted with a silicon nitride film accumulated on the inside of the process tube 203 (that is, exhaustion of gas that does not contribute to cleaning anymore), and introduction of a new cleaning gas are repeated, so that cleaning can be effectively performed with a shorter time and less consumption of cleaning gas.
[0105] When cleaning a silicon film attached to the inner wall of the first nozzle 233 a which is used to supply a silicon source such as DCS, pressure is kept lower than a pressure at which the inside of the process tube 203 is cleaned, so as to weaken cleaning reaction power for preventing damage of a quartz part. In addition, if reaction power is high, heat generation may increase to cause breakage of a quartz part, and if reaction speed is high, a silicon film may decompose destructively to cause contamination. That is, these disadvantages can be prevented.
[0106] When cleaning a silicon film attached to the inner wall of the first nozzle 233 a which is used to supply a silicon source such as DCS, supply and exhaustion of a cleaning gas are continuously performed instead of alternately repeating them, so that gas participated in reaction and not participated in reaction can be efficiently discharged and the cleaning process can be rapidly completed.
(4) Another Embodiment
[0107] According to another embodiment, a method of cleaning the process tube 203 will now be described with reference to FIG. 6 and FIG. 8 . The same elements as those shown in FIG. 1 will be denoted by the same reference numerals, and descriptions thereof will not be repeated.
[0108] At a first cleaning gas supply pipe 300 , a gas reservoir 306 and an on-off valve such as a fifth valve 308 are installed as well as a flowrate control device such as a third MFC 302 and an on-off valve such as a third valve 304 , and the fifth valve 308 is configured to be controlled by a controller 280 .
[0109] (Step 31 )
[0110] First, ClF 3 gas is filled in a process chamber 201 as follows: in a state where the inside of the process chamber 201 is exhausted by opening an APC valve 242 (a fourth valve 354 is closed), the third valve 304 is opened and the fifth valve 308 is closed so as to introduce ClF 3 gas into the first cleaning gas supply pipe 300 and store the ClF 3 gas in the gas reservoir 306 while controlling the flowrate of the ClF 3 using the third MFC 302 (Step 31 ).
[0111] (Step 32 )
[0112] If a predetermined amount of ClF 3 gas is stored in the gas reservoir 306 , the third valve 304 is closed to stop an inflow of ClF 3 gas into the gas reservoir 306 . In this state, the ClF 3 gas stored in the gas reservoir 306 is supplied to the process chamber 201 at a time (a flash flow) by opening the fifth valve 308 so as to fill the inside of the process chamber 201 with the ClF 3 gas. In addition, the APC valve 242 is opened to control the inside pressure of the process chamber 201 to a predetermined level (Step 32 ).
[0113] (Step 33 )
[0114] Like the case where the gas reservoir 306 is not used, gas filled in the process chamber 201 is exhausted (Step 33 ). After a predetermined time from the opening of the APC valve 242 , the process of Step 33 is completed.
[0115] After that, Step 31 , Step 32 , and Step 33 are set as one cycle, and this cycle is repeated predetermined times. In this way, cleaning of the inside of the process tube 203 is completed.
[0116] While the process of Step 32 is performed, Step 31 may be concurrently performed to store ClF 3 gas in the gas reservoir 306 (that is, the third valve 304 is opened and the fifth valve 308 is closed to store ClF 3 gas in the gas reservoir 306 ). In this case, the process time of the entire cleaning process can be reduced.
[0117] Furthermore, without Step 31 for storing ClF 3 gas in the gas reservoir 306 , ClF 3 gas may be supplied to the inside of the process chamber 201 and filled in the inside of the process chamber 201 only by manipulating each valve.
[0118] As described above, when a silicon nitride film attached to the inside of the process tube 203 is cleaned, a cleaning gas is instantaneously supplied to the inside of the process tube 203 to increase the gas concentration of the inside of the process tube 203 and fill the cleaning gas in the entire inside of the process tube 203 . By increasing pressure in this way, particularly, the effect of gas flow distribution in the upper region of the process chamber 201 can be reduced, and cleaning can be performed within a shorter time.
[0119] In addition, since the temperature of the lower side of the process tube 203 is lower than temperature of the upper side of the process tube 203 , it is more difficult to remove a silicon nitride film attached to the lower side of the process tube 203 . Therefore, a cleaning process may be divided into a process of cleaning the entire inside of the process tube 203 and a process of cleaning the lower side of the process tube 203 , and the process of cleaning the entire inside of the process tube 203 may be performed at a high pressure (high-pressure cycle) but the process of cleaning the lower side of the process tube 203 may be performed at a relatively low pressure (low-pressure cycle). In the case of the low-pressure process, it is preferable that a cleaning gas be continuously supplied instead of supplying the cleaning gas instantaneously. In this way, the cleaning process of the inside of the process tube 203 may be performed in two cleaning steps: a high-pressure intermittent cleaning step and a low-pressure continuous cleaning step. Alternatively, in a way of varying pressure when a cleaning gas is supplied, silicon nitride films attached to the upper and lower sides of the process tube 203 may be preferentially removed.
[0120] In the above described description, a silicon-rich silicon nitride film is described as a film to be formed on a substrate; however, the present invention is not limited thereto. For example, the present invention can be applied to apparatuses configured to form films such as a silicon nitride film having a stoichiometric composition ratio, an aluminum nitride film, a titanium nitride film, a hafnium nitride film, a zirconium nitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, a titanium oxide film, a hafnium oxide film, a zirconium oxide film, and a silicon oxide film. That is, the present invention can be applied to an apparatus in which different kinds of films are formed on the inside of a process tube and the inner wall of a gas supply nozzle (i.e., an apparatus including gas supply nozzles for respective process gases).
[0121] In addition, besides a silicon (Si)-containing gas, a metal element-containing gas such as an aluminum (AD-containing gas, a titanium (Ti)-containing gas, a hafnium (Hf)-containing gas, and a zirconium (Zr)-containing gas may be used as a process gas capable of depositing a film by itself at a certain temperature, and besides a nitrogen (N)-containing gas, gas such as an oxygen (O)-containing gas may be used as a process gas incapable of depositing a film by itself at a certain temperature.
[0122] Furthermore, although chlorine trifluoride (ClF 3 ) is described as an example of a cleaning gas, the present invention is not limited thereto. For example, gas including at least one gas selected from the group consisting of nitrogen trifluoride (NF 3 ) gas, fluorine (F 2 ) gas, hydrogen fluoride (HF) gas, chlorine (Cl 2 ) gas, and boron trichloride (BCl 3 ) gas may be used as a cleaning gas.
[0123] According to the method of manufacturing a semiconductor device, the cleaning method, and the substrate processing apparatus of the present invention, the reaction tube and the gas supply nozzle can be cleaned under conditions optimized according to the film-forming conditions of the reaction tube and the gas supply nozzle, thereby making it possible to perform a cleaning process with less contamination and damages on the reaction tube and the gas supply nozzle.
[0124] <Supplementary Note>
[0125] The present invention also includes the following preferred embodiments.
[0126] (Supplementary Note 1)
[0127] According to an embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: loading a substrate into a process chamber; forming a film on the substrate by supplying a first process gas, which comprises at least one of a plurality of elements constituting the film and is capable of depositing a film by itself, to an inside of the process chamber through a first gas introducing part, and supplying a second process gas, which comprises at least one of the others of the plurality of elements constituting the film and is incapable of depositing a film by itself, to the inside of the process chamber through a second gas introducing part; unloading the substrate from the process chamber after the film is formed on the substrate; performing a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying a cleaning gas to the first gas introducing part; and performing a second cleaning process so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by supplying a cleaning gas to the inside of the process chamber through a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, wherein in the performing of the first cleaning process, cleaning conditions are set according to accumulated supply time of the first process gas supplied to the inside of the process chamber through the first gas introducing part, and in the performing of the second cleaning process, cleaning conditions are set according to an accumulated thickness of the film formed on the substrate.
[0128] (Supplementary Note 2)
[0129] Preferably, the cleaning conditions may be a pressure of the inside of the process chamber and a flowrate of the cleaning gas.
[0130] (Supplementary Note 3)
[0131] Preferably, a pressure of the inside of the process chamber in the first cleaning process may be set to be lower than a pressure of the inside of the process chamber in the second cleaning process.
[0132] (Supplementary Note 4)
[0133] Preferably, the first deposition substance may comprise at least one of the plurality of elements as a main component, and the second deposition substance may comprise the plurality of elements as main components.
[0134] (Supplementary Note 5)
[0135] Preferably, the first process gas may be a silicon-containing gas, and the second process gas may be a nitrogen-containing gas.
[0136] (Supplementary Note 6)
[0137] Preferably, the cleaning gas may comprise at least one selected from the group consisting of nitrogen trifluoride (NF 3 ) gas, chlorine trifluoride (ClF 3 ) gas, fluorine (F 2 ) gas, hydrogen fluoride (HF) gas, chlorine (Cl 2 ) gas, and boron trichloride (BCl 3 ) gas.
[0138] (Supplementary Note 7)
[0139] Preferably, in the first cleaning process, the cleaning gas may be continuously supplied to the first gas introducing part, and in the second cleaning process, the cleaning gas may be intermittently supplied to the inside of the process chamber.
[0140] (Supplementary Note 8)
[0141] According to another embodiment of the present invention, there is provided a cleaning method for removing a film attached to an inside of a process chamber of a substrate processing apparatus which is used to form a film on a substrate by supplying a process gas to the substrate, the cleaning method comprising: setting pressure of the inside of the process chamber to a first pressure and intermittently supplying a cleaning gas to the inside of the process chamber; and setting the pressure of the inside of the process chamber to a second pressure higher than the first pressure and continuously supplying the cleaning gas to the inside of the process chamber.
[0142] (Supplementary Note 9)
[0143] According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: loading a substrate into a process chamber; forming a film on the substrate by supplying a first process gas, which comprises at least one of a plurality of elements constituting the film and is capable of depositing a film by itself, to an inside of the process chamber through a first gas introducing part, and supplying a second process gas, which comprises at least one of the others of the plurality of elements constituting the film and is incapable of depositing a film by itself, to the inside of the process chamber through a second gas introducing part; unloading the substrate from the process chamber after the film is formed on the substrate; performing a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying a cleaning gas to the first gas introducing part; and performing a second cleaning process so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by supplying a cleaning gas to the inside of the process chamber through a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, wherein when at least parts of the first cleaning process and the second cleaning process are simultaneously performed, concentration of the cleaning gas supplied to the first gas introducing part is lower than concentration of the cleaning gas supplied through the third gas introducing part.
[0144] (Supplementary Note 10)
[0145] According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: loading a substrate into a process chamber; forming a film on the substrate by supplying a first process gas, which comprises at least one of a plurality of elements constituting the film and is capable of depositing a film by itself, to an inside of the process chamber through a first gas introducing part, and supplying a second process gas, which comprises at least one of the others of the plurality of elements constituting the film and is incapable of depositing a film by itself, to the inside of the process chamber through a second gas introducing part; unloading the substrate from the process chamber after the film is formed on the substrate; performing a first cleaning process so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by supplying a cleaning gas to the first gas introducing part; and performing a second cleaning process so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by supplying a cleaning gas to the inside of the process chamber through a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed, wherein when at least parts of the first cleaning process and the second cleaning process are simultaneously performed, a flowrate of the cleaning gas supplied to the first gas introducing part is lower than a flowrate of the cleaning gas supplied through the third gas introducing part.
[0146] (Supplementary Note 11)
[0147] According to another embodiment of the present invention, there is provided a substrate processing apparatus comprising: a process chamber configured to accommodate a substrate; a first gas introducing part configured to supply a first process gas, which comprises at least one of a plurality of elements constituting a film to be formed on the substrate and is capable of depositing a film by itself, and a cleaning gas to an inside of the process chamber; a second gas introducing part configured to supply a second process gas, which comprises at least one of the others of the plurality of elements and is incapable of depositing a film by itself, to the inside of the process chamber; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed and configured to supply a cleaning gas to the inside of the process chamber; an exhaust part configured to exhaust an inside atmosphere of the process chamber; and a control unit configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, wherein after a film is formed on the substrate by supplying the first and second process gases to the inside of the process chamber, the control unit controls the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, so as to remove a first deposition substance attached to an inner wall of the first gas introducing part by setting cleaning conditions according to accumulated supply time of the first process gas supplied to the inside of the process chamber through the first gas introducing part and supplying a cleaning gas to the first gas introducing part, and so as to remove a second deposition substance attached to the inside of the process chamber and having a chemical composition different from that of the first deposition substance by setting cleaning conditions according to an accumulated thickness of the film formed on the substrate and supplying a cleaning gas to the inside of the process chamber through the third gas introducing part.
[0148] (Supplementary Note 12)
[0149] Preferably, the cleaning conditions may be a pressure of the inside of the process chamber and a flowrate of the cleaning gas.
[0150] (Supplementary Note 13)
[0151] Preferably, the control unit may control the first gas introducing part, the third gas introducing part, and the exhaust part, such that a pressure of the inside of the process chamber when the cleaning gas is supplied through the third gas introducing part is lower than a pressure of the inside of the process chamber when the cleaning gas is supplied through the first gas introducing part.
[0152] (Supplementary Note 14)
[0153] Preferably, the first deposition substance may comprise at least one of the plurality of elements as a main component, and the second deposition substance may comprise the plurality of elements as main components.
[0154] (Supplementary Note 15)
[0155] According to another embodiment of the present invention, there is provided a substrate processing apparatus comprising: a process chamber configured to accommodate a substrate; a first gas introducing part configured to supply a first process gas, which comprises at least one of a plurality of elements constituting a film to be formed on the substrate and is capable of depositing a film by itself, and a cleaning gas to an inside of the process chamber; a second gas introducing part configured to supply a second process gas, which comprises at least one of the others of the plurality of elements and is incapable of depositing a film by itself, to the inside of the process chamber; a third gas introducing part connected to a lower side of the process chamber at a position where the substrate is not placed and configured to supply a cleaning gas to the inside of the process chamber; an exhaust part configured to exhaust an inside atmosphere of the process chamber; and a control unit configured to control the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, wherein after a film is formed on the substrate by supplying the first and second process gases to the inside of the process chamber, the control unit controls the first gas introducing part, the second gas introducing part, the third gas introducing part, and the exhaust part, so as to set pressure of the inside of the process chamber to a first pressure and supply a cleaning gas intermittently to the inside of the process chamber through the third gas introducing part, and so as to set the pressure of the inside of the process chamber to a second pressure lower than the first pressure and supply the cleaning gas continuously to the inside of the process chamber through the third gas introducing part.
[0156] (Supplementary Note 16)
[0157] According to another embodiment of the present invention, there is provided a cleaning control apparatus for a process chamber or a silicon-containing gas supply system of a silicon nitride film forming apparatus which is used to form a silicon nitride film having a predetermined silicon/nitrogen composition ratio on a substrate by alternately supplying a silicon-containing gas having a predetermined molecular weight and a nitriding source gas having a predetermined molecular weight, the cleaning control apparatus comprising: a cleaning request signal output unit comprising a memory unit configured to store an accumulated supply amount of silicon-containing gas molecules supplied to an inside of the process chamber through the silicon-containing gas supply system, the cleaning request signal output unit being configured to output a cleaning request signal so as to request cleaning of the silicon-containing gas supply system if the accumulated supply amount of the silicon-containing gas molecules stored in the memory unit becomes equal to or greater than a preset accumulated supply amount of silicon-containing gas molecules; and a cleaning request signal output unit comprising a memory unit configured to store an accumulated supply amount of nitriding source gas molecules supplied to the inside of the process chamber through a nitriding source gas supply system, the cleaning request signal output unit being configured to output a cleaning request signal so as to request cleaning of the nitriding source gas supply system if the accumulated supply amount of the nitriding source gas molecules stored in the memory unit becomes equal to or greater than a preset accumulated supply amount of nitriding source gas molecules.
[0158] (Supplementary Note 17)
[0159] According to another embodiment of the present invention, there is provided a cleaning control apparatus for a process chamber or a gas introducing part of a substrate processing apparatus which is used to form a predetermined film on a substrate placed in the process chamber by supplying a first process gas comprising at least one of a plurality of elements constituting the film and a second process gas comprising at least one of the others of the plurality of elements constituting the film to an inside of the process chamber through different gas introducing parts, respectively, the cleaning control apparatus comprising: a first monitoring unit configured to monitor a supply amount of the first process gas supplied to the inside of the process chamber through a first introducing part; a first adding unit configured to accumulate the monitored supply amount of the first process gas; a first memory unit configured to store the accumulated supply amount of the first process gas; a first comparison unit configured to compare the accumulated supply amount of the first process gas with a predetermined threshold value; a first signal output unit configured to output a cleaning request signal so as to request cleaning of an inner wall of the first introducing part if the accumulated supply amount of the first process gas is greater than the predetermined threshold valve; a second monitoring unit configured to monitor a supply amount of the second process gas supplied to the inside of the process chamber through a second introducing part; a second adding unit configured to accumulate the monitored supply amount of the second process gas; a second memory unit configured to store the accumulated supply amount of the second process gas; a second comparison unit configured to compare the accumulated supply amount of the second process gas with a predetermined threshold value; and a second signal output unit configured to output a cleaning request signal so as to request cleaning of an inner wall of the second introducing part if the accumulated supply amount of the second process gas is greater than the predetermined threshold valve.
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A cleaning control apparatus capable of performing a cleaning process efficiently regardless of qualities and thicknesses of films formed in a process tube and a gas supply nozzle. The cleaning control apparatus employs cleaning request signal output units configured to output cleaning request signals requesting cleaning processes of a silicon-containing gas supply system and nitriding source gas supply system when accumulated amounts of the molecules of the silicon-containing gas and the nitriding source gas exceeds preset values.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No. PCT/EP98/04991, filed Jul. 28, 1998, in the European Patent Office, the content of which is relied upon and incorporated herein by reference; additionally, Applicants claim the right of priority under 35 U.S.C. §119(a)-(d) based on patent application No. 97202433.5, filed Aug. 5, 1997, in the European Patent Office; further, Applicants claim the benefit under 35 U.S.C. §119(e) based on prior-filed, copending provisional application No. 60/059,986, filed Sep. 25, 1997, in the U.S. Patent and Trademark Office.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a superconducting cable of the so-called high temperature type, and a manufacturing process for the same.
2. Description of the Related Art
The term superconducting material, as employed throughout the description and the appended claims, refers to any material, such as for instance ceramic materials based on mixed oxides of copper, barium and yttrium or of bismuth, lead, strontium, calcium, copper, thallium and mercury, comprising a superconducting stage having an almost null resistivity at temperatures below a so-called critical temperature Tc.
In the field of superconductors and, accordingly, in the present description, the term high temperature refers to any temperature near to or higher than the temperature of liquid nitrogen (about 77° K), compared to the temperature of liquid helium (about 4° K), usually indicated as low temperature.
High temperature superconducting cables are known for instance from DE-A-3811050 and EP-A-0747975.
Superconducting materials are known that have a critical temperature higher than 77° K, i.e. that show superconductivity characteristics at least up to such temperature. These materials are usually referred to as high temperature superconductors. Such materials are obviously of a greater technical interest with respect to low temperature superconductors, as their working may be ensured by liquid nitrogen refrigeration at 77° K instead of liquid helium at 4° K, with much lower implementation difficulties and energy costs.
As known, in the field of electric energy transportation, one of the problems of most difficult solution is that of rendering more and more advantageous the use of the so-called superconducting materials, from both the technological and the economic points of view.
In fact, even though these low temperature materials have been known for a long time, their diffusion was limited till now to some well defined practical applications, such as for instance the fabrication of magnets for NMR apparatuses or high field magnets for which cost is not a discriminating factor.
Actually, cost savings due to less power being dissipated by superconductors is still more than counterweighted by costs due to liquid helium refrigeration, necessary to keep the latter below its critical temperature.
In order to solve the aforesaid problem, research is partly oriented towards experimenting new high temperature superconducting materials, partly tries to constantly improve both the characteristics of the existing materials and the performances of conductors incorporating already available materials.
With regard to geometric characteristics, it has been found that an advantageous geometry is provided by thin tapes having, generally, a thickness between 0.05 mm and 1 mm.
In fact, in such case the conductor comprising the very brittle superconducting ceramic material achieves on one hand an improved resistance to various bending stresses to which it is submitted during each manufacturing, shipping and installing operations of the cable containing it, and on the other hand it provides better performances with regard to critical current density, because of the more advantageous orientation and compacting degree of the superconducting material.
For various reasons and in particular to improve mechanical resistance, the above conductors generally comprise a plurality of tapes, formed each by a core of superconducting material enclosed in a metal envelope—generally of silver or silver alloys—coupled together to obtain a multi-filament composite structure.
According to a widely used method, known to those skilled in the art as “powder-in-tube”, this multi-filament structure of the conductor is obtained starting from small metal tubes filled with a suitable powder precursor, said tubes being in their turn enclosed in another external metal tube or a billet, so as to obtain a compact bundle of tubes which are submitted first to several subsequent permanent deformation, extrusion and/or drawing treatments, then to rolling mill and/or pressing treatments, until the desired tape-shaped structure is obtained. See for instance EP-A-0627773.
Between a rolling mill treatment and the subsequent one, the tape being worked is submitted to one or more heat treatments to cause formation of the superconducting ceramic material starting from its precursor and, above all, its syntherisation, i.e. the mutual “welding” of the granules of the powdered superconductor.
The tapes of high temperature superconductors are rather brittle, both at the working temperature of 77° K and at room temperature, and are unsuited to stand mechanical stresses, especially tensile stresses. In fact, apart from an actual mechanical breaking, exceeding a given tensile deformation threshold irreversibly jeopardises the superconduction characteristics of the material. Therefore, using these materials in cables is particularly complex and delicate.
In fact, the manufacturing and installation of cables comprising such materials involves several stages which bring about unavoidably mechanical stresses.
A first critical stage is winding of several tapes on a flexible tubular support according to a spiral arrangement, until the desired section of superconducting material is obtained. Both winding and pull cause tensile, bending and torsion deformations in tapes. The resulting stress applied to the superconducting material is mainly a tensile stress. Besides, the so formed conductor (support plus superconducting material) is surrounded by heat and electric insulation means, and is submitted, during these operations, to tractions and bendings that introduce more stresses in superconducting tapes.
A second critical stage concerns cable installation. The cable is installed at room temperature, which causes additional tensile and bending stresses. Mechanical connections (i.e., locking of cable heads), electric connections, and hydraulic connections (i.e., for liquid nitrogen) are carried out at room temperature. After completing installation, the cable is brought to its working temperature by feeding liquid nitrogen. During such cooling, each cable component is subject to mechanical stresses of thermal origin, differing according to the thermal expansion coefficient of the constituting material and of the characteristics of the other elements.
In particular, the differences of expansion coefficients between the support and the superconducting tape may cause stresses in the latter and therefore in the superconducting material. In fact, if the superconducting material cannot shrink freely being tied to a less shrinkable support, tensile strains generate in the superconducting material. Such tensile strains add to those already present, due to winding.
To reduce tensile strains, the use of supports has been suggested that are made of a material having an expansion coefficient higher than that of the superconducting material (usually equal to 10×10 −6 /K-20×10 −6 /K), i.e., on the order of at least 75×10 −6 /K. Such material would not be a metal, as no known metal has such values, but only a polymeric material such as, for instance, Teflon®, polyethylene, and derivatives thereof.
However, it has been found that the aforesaid solution, whose aim is to reduce thermomechanical stresses on tapes through a suitable reduction in the support diameter, shows some important drawbacks.
In particular, the unavoidably high values of heat contraction of the conductor (support plus superconducting material) cause the formation of a wide radial hollow space between the conductor itself and the surrounding insulating means (thermal and/or electric insulation). This hollow space may cause electric inconveniences, with deformation or breaking of the insulation, and/or mechanical inconveniences, namely lack of cohesion, misalignment and slipping of the conductor.
Besides, poor mechanical characteristics of said polymer material do not allow to protect the superconducting material adequately during cable manufacturing and installation phases: because of the high deformability of these materials any strain applied to conductors causes indeed a remarkable deformation also in the superconducting material.
SUMMARY OF THE INVENTION
Therefore, the invention relates, in a first aspect, to a high temperature superconducting cable, comprising a tubular support, a plurality of superconducting tapes including a superconducting material enveloped in a metal covering (for instance, silver or a silver-based alloy with magnesium and/or aluminium and/or nickel), said tapes being spirally wound on the support, so as to form an electroinsulated, thermally-insulated and refrigerated superconducting layer, characterised in that the superconducting tapes have a maximum tensile deformation greater than 3‰.
The above value is to be intended as referred to the manufacturing and installation process described above, i.e.: winding and installation at room temperature, then cooling to working temperature of about 77° K. The same applies also to the deformation values that will be given in the following.
Preferably, the superconductive tapes comprise at least a metal strip (or band or laminate) connected to the metal covering.
In this way, the capability of bearing tensile stresses increases. It has been observed that tensile deformation safely bearable by superconducting materials may be—at best—about 3‰. This figure takes into account the fact that the superconducting materials already bear a compression deformation of about 1‰-1.5‰ because of the different thermal contraction of the superconducting material relative to the metal covering during the tape fabrication stage.
Thanks to the metal strip of the invention, not only a lower deformation under the same applied strains has been observed, but especially an improved tensile deformation resistance; elongation values equal to about 5.5‰ have been actually reached without any damage. This effect is thought to be due to a more uniform distribution of strains in the superconducting material, that allows to better exploit the mechanical characteristics of said superconducting material.
According to each individual case, only one strip coupled to the metal covering, or two strips, located at the opposite sides of the tape, can be provided.
Preferably, the metal strip is coupled to the metal covering by welding, brazing or gluing.
Preferably, the strip is made of non magnetic stainless steel having a low electric conductivity, or also of bronze or aluminium.
Preferably, the tubular support of the cable is made of metal. The greater capability of bearing tensile stresses allows indeed to use a support made of metal instead of polymeric material, as will be better explained in the following.
Various types of metals may be used for the support; in particular, for applications with very high currents, non-magnetic steel is used, preferably stainless steel. Alternatively, copper or aluminium may also be used.
The structure of the tubular support may be continuous, either smooth or corrugated. Alternatively, the tubular support may have a structure formed by a spirally wound metal tape, or may have a so-called tile-structure, i.e. with spirally connected adjacent sectors.
In a second aspect, the invention relates to a process for manufacturing high temperature superconducting cables, comprising the steps of:
providing a tubular support,
enclosing a superconductive material in a metal covering, so as to form superconductive tapes,
spirally winding a plurality of superconducting tapes onto the support so as to form at least a superconducting layer,
electroinsulating the superconductive layer,
thermally insulating the superconductive layer,
providing the possibility of refrigerating the superconductive layer below a predetermined working temperature, when cables are in use, characterised by
controlling the maximum tensile deformation of the superconducting tapes to have it greater than 3‰.
This process allows to manufacture cables according to the first aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of a cable and a process according to the invention will appear more clearly from the following description of a preferred embodiment, wherein reference is made to the attached drawings. In the drawings:
FIG. 1 is a schematic view of a high-temperature, superconducting cable according to the invention, with portions cut away for viewing clarity;
FIG. 2 is a cross-sectional, schematic view of a high-temperature, superconducting tape with a metal strip, band, or laminate utilised in the cable of FIG. 1;
FIG. 3 is a cross-sectional, schematic view of a high-temperature, superconducting tape with two metal strips, bands, laminates, or combinations thereof, utilised in the cable of FIG. 1;
FIG. 4 a is a perspective view of a tubular support with one type of smooth structure;
FIG. 4 b is a perspective view of a tubular support with one type of corrugated structure;
FIG. 4 c is a perspective view of a tubular support with one type of spirally-wound structure, shown partially unwound; and
FIG. 4 d is a perspective view of a tubular support with one type of tile structure, shown partially unwound.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, 1 indicates a one-phase superconducting cable 1 of the so-called co-axial type as a whole. Cable 1 comprises a superconducting core, globally indicated by 2 , comprising at least a conducing element 3 ; the illustrated example relates (according to the European patent application no. 96203551.5 of the same applicant) to a cable wherein four conducting elements are provided, indicated by 3 I , 3 II , 3 III , 3 IV , housed—preferably loosely—within a tubular casing 9 , for instance of metal, such as steel, aluminium and the like.
Each of the conducting elements 3 comprises a couple of co-axial conductors, respectively of phase 4 and of neutral 5 , including each at least a layer of superconducting material.
In said example, the superconducting material is incorporated in a plurality of superposed superconducting tapes 20 , spirally wound on respective tubular supports 6 and (possibly) 7 , with a sufficiently low winding angle α; if the tubular support is metal, the angle α is preferably smaller than 40°, as will be illustrated in the following.
Co-axial phase 4 and neutral 5 conductors are electrically insulated from one another by means of an interposed layer 8 of dielectric material.
Cable 1 also comprises suitable means to refrigerate the superconducting core 3 to a temperature suitably lower than the critical temperature of the chosen superconducting material, which in the cable of FIG. 1 is of the so-called “high temperature” type.
The aforesaid means comprise suitable, known and thus not represented, pumping means, whose purpose is feeding a suitable refrigerating fluid, for instance liquid nitrogen at a temperature of from 65° to 90° K, both in the interior of each of the conducting elements 3 , and in the interstices between such elements and the tubular casing 9 .
To reduce as much as possible thermal dispersions toward environment, the superconducting core 2 is enclosed in a holding structure, or cryostat, 10 comprising a thermal insulation formed, for instance, by a plurality of superposed layers, and at least a protection sheath.
A cryostat, known in the art, is described for instance in an article by IEEE TRANSACTIONS ON POWER DELIVERY, vol. 7, no. 4, October 1992, pp. 1745-1753.
More particularly, in said example, cryostat 10 comprises a layer 11 of insulating material, constituted for instance by several tapes (some dozens) from surface-metallised plastic material (for instance polyester resin), known in the art as “thermal superinsulator”, loosely wound, possibly with the aid of interposed spacers 13 .
Such tapes are housed in an annular hollow space 12 , delimited by a tubular element 14 , in which vacuum of about 10 −2 N/m 2 is maintained by means of known apparatuses.
The metal tubular element 14 is suitable to give the annular hollow space 12 the desired impermeability, and is covered by an external sheath 15 , for instance of polyethylene.
Preferably, the metal tubular element 14 is formed by a tape wound in tubular shape and longitudinally welded, made of steel, copper, aluminium and the like, or by an extruded tube or the like.
If required for cable flexibility, element 14 may be corrugated.
In addition to the described elements, cable traction elements may also be present, axially or peripherally located based on the construction and use requirements of the same, to ensure limitation of mechanical stresses applied to superconducting elements 3 . Such traction elements, not shown, may be constituted, according to techniques known in the art, by peripherally-placed metal armours, for instance, by roped steel wires, or by one or more axial metal cords, or by armouring fibers of dielectric material, for instance, aramid fibers.
Preferably, the tubular supports 6 and 7 are made of non magnetic stainless steel, and may have a continuous, either smooth or corrugated, structure; alternatively, tubular supports 6 and 7 may be realised with a spirally wound steel strip or with a tile structure. Materials different from steel may also be used, such as copper or aluminium.
Each superconducting tape 20 , as shown in FIG. 2, comprises superconducting material 23 , a metal covering 24 (preferably from silver or silver alloy with magnesium, aluminium or nickel), wherein the superconducting material 23 is enclosed, and at least a metal strip (or band or laminate) 25 coupled to covering 24 . In particular, covering 24 has a substantially rectangular flattened section with two long sides 26 and two short sides 27 ; also strip 25 has a substantially rectangular flattened section with two long sides 28 of a length almost equal to the long sides 26 of covering 24 . Strip 25 is fastened to covering 24 by welding, brazing or gluing. It should be noted that there may be two strips 25 , either equal or different, fastened to opposite parts of covering 24 .
EXAMPLE
To put into practice the invention, some cables have been realised having the following characteristics:
support:
metal or polymer
winding diameter (external diameter of the support):
40 mm
angle α:
10-45°
thickness of superconducting tape:
0.2 mm
width of superconducting tape:
4 mm
pull on individual tapes during winding:
10 N
working temperature:
77° K
refrigeration with locked heads (temperature jump equal to 220° K)
heat expansion coefficient of superconducting tape:
18.5×10 −6 ° C.
heat expansion coefficient of polymer support:
80×10 −6 ° C.
heat expansion coefficient of metal support:
15×10 −6 ° C.
The deformation effects on the superconducting material have been taken into account, both those due to winding geometry (which depend on bending imparted to the tape and which therefore increase as angle α increases), and those due to pull during winding operation (constant), and those with locked cable heads due to the effect of thermal variation (which decrease as angle α increases, until they may become negative with a sufficiently great α). In the tables, positive figures have been used to indicate pulling deformations, negative figures to indicate compression deformations.
The tables show the feasibility of both a conventional superconducting tape, with a maximum bearable tensile deformation equal to 3‰, and a superconducting tape according to the invention (provided with two strips 25 located along sides 26 of the section, having a thickness of 0.045 mm and a length of 3.8 mm, made of stainless steel, and bonded to covering 24 of the strip by tin brazing), with a maximum bearable tensile deformation equal to 5.5‰ (a 2.5‰ improvement). In the latter case, the minimum increase value of tensile deformation resistance necessary to ensure feasibility has been indicated, assuming (as indicated above and practically verified) that the superconducting non-reinforced tape can bear a 3‰ tensile deformation. Double-underlined values indicate that the 3‰ limit has been exceeded.
Table 1 summarises the situation in the case of a polymeric support, table 2 that relating to the case of a metal support.
The example shows, in a specific case, that generally the invention allows a greater design freedom as concerns winding angles, support diameter, winding pull value, and, to some extent, choice of material for the support.
The possibility of using a metal for the support is particularly advantageous, as such support, besides imparting a greater solidity to the cable, therefore with a better protection for the superconducting material, above all allows to prevent those drawbacks of polymeric supports mentioned above for the prior art; this means that no dangerous hollow spaces form at the working temperature between the conductor and the surrounding layers, due to differences in heat expansion coefficient. Because in the cable the layers external with respect to the conductor are—as has been seen—prevailingly metal, using a metal support minimises expansion differences and therefore drastically reduces inconveniences due to hollow spaces.
Besides, the metal support lends a greater mechanical resistance to the conductor, understood as the whole of the support and the superconducting material wound on the same. Hence, possible mechanical stresses on the conductor are not transmitted to a great extent to superconducting tapes (as happens with polymer supports because of their high deformability), but are instead almost entirely borne by the same support.
Also the possibility of increasing the winding pull of the superconducting material is a very important advantage. In fact, compactness of the conductor winding, and therefore its stability, depends on said pull.
To sum up, the invention allows to realise less delicate and more resistant superconducting cables.
Feasibility
by a con-
Minimum
Wind-
Geometric
Pull
Thermal
Total
ventional
necessary
Feasibility by
ing
winding
defor-
defor-
defor-
supercon-
improve-
an improved
angle
deformation
mation
mation
mation
ducting
ment
superconducting
°
{fraction (o/oo)}
{fraction (o/oo)}
{fraction (o/oo)}
{fraction (o/oo)}
tape
{fraction (o/oo)}
tape
10
0.3
0.25
3.5
4.05
NO
1.05
YES
25
1.4
0.25
0.93
2.58
YES
—
YES
28.7
1.75
0.25
0
2
YES
—
YES
45
3.4
0.25
−4
(−0.35) 1
NO
0.4
YES
For a conventional superconducting tape, the mere geometric deformation at room temperature is sufficient to irreversibly damage the tape itself. Therefore, the −0.35 value is significant only for the improved superconducting tape.
Feasibility
by a con-
Minimum
Wind-
Geometric
Pull
Thermal
Total
ventional
necessary
Feasibility by
ing
winding
defor-
defor-
defor-
supercon-
improve-
an improved
angle
deformation
mation
mation
mation
ducting
ment
superconducting
°
{fraction (o/oo)}
{fraction (o/oo)}
{fraction (o/oo)}
{fraction (o/oo)}
tape
{fraction (o/oo)}
tape
10
0.3
0.25
4
4.55
NO
1.55
YES
25
1.4
0.25
3.5
5.15
NO
2.15
YES
28.7
1.75
0.25
3.3
5.3
NO
2.3
YES
45
3.4
0.25
2.42
6.07
NO
3.07
NO
|
A high temperature superconducting cable includes a tubular support and a plurality of superconducting tapes. The superconducting tapes include a superconducting material enclosed in a metal covering, spirally wound onto the tubular support to form at least an electroinsulated, thermally-insulated, and refrigerated superconducting layer. The superconducting tapes also include at least a metal strip coupled to the metal covering. A process for manufacturing high temperature superconducting cables is also disclosed.
| 7
|
FIELD OF THE INVENTION
[0001] The present invention relates to vaccines against avian diseases, and more particularly, to vaccines against diseases associated with Avian Malabsorption Syndrome (MAS), as well as to methods of administration therefor to poultry.
BACKGROUND OF THE INVENTION
[0002] Avian Malabsorption Syndrome (MAS) is a disease of growing poultry, especially chickens, with meat-type or broilers being affected most commonly. The syndrome has been reported in the Netherlands (Kouwenhoven et.al; 1978) as “Runting and Stunting Syndrome” in broilers. It is known worldwide under different names. Synonyms include infectious stunting syndrome, pale bird syndrome, helicopter disease, infectious proventriculitis, brittle bone disease and femoral head necrosis.
[0003] Kouwenhoven et al. (Avian Pathology 17, 879-892, 1988) further defined MAS by five criteria:
1) growth impairment up to 3 weeks after infection of one-day old chicks; 2) excretion of yellow orange mucoid to wet droppings; 3) increased plasma alkaline phosphatase (ALP) activity; 4) decreased plasma carotenoid concentration (PCC); and 5) macroscopically widened epiphyseal growth plates of the proximal tibia.
The condition has been further characterized by stunted growth, poor feathering, lack of skin pigmentation, enteritis and bone disorders.
[0009] Vertommen et. al (1980a and 1980b) transmitted the disease by oral inoculation of intestinal homogenates from affected chicks into one-day-old broilers. In this experiment, it was demonstrated that low plasma carotenoid levels and elevated plasma alkaline phosphatase activities are suitable tools for the diagnosis of MAS. In further experiments, MAS was transmitted by oral inoculation of liver homogenates from affected chicks into one-day-old broilers. Despite years of research, the etiology of MAS has not yet been fully established, and the condition is still a major problem for the poultry industry. It is believed that a virus is responsible, but bacteria or other microorganisms have not been excluded as causal agents.
[0010] Viruses that have been associated with outbreaks of MAS possibly include reoviruses, rotaviruses, parvoviruses, entero-like viruses and a toga-like virus (M. S. McNulty and J. B. McFerran; 1993). McNulty, World Poultry 14, 57-58 (1998), however, has postulated that identification of the causative agent is still unknown and recommends control by careful management of production sites. It is now believed by the present inventors that the adenovirus may play a role in the development of MAS.
[0011] At present, an MAS-like disease occurs in layer replacement birds in the Netherlands. The disease has a negative effect on the growth of the chicks and also has a negative effect on the laying performance of the mature hens. The disease occurs countrywide, but the diagnosis has not yet been confirmed by transmission of the disease into susceptible chicks.
[0012] EP 1024189 indicates that a vaccine for protection against the enteric symptoms of MAS can be prepared from an avian reovirus. However, the need exists for a vaccine which protects against both enteric symptoms and bone disorders associated with MAS to a much greater extent. There also exists a need to protect against as many causative viral agents of MAS as possible.
[0013] It is therefore an object of the present invention to provide a vaccine for the prevention of MAS in commercial avian species, such as chickens, turkeys and other fowl, especially those of “broiler” age.
[0014] The vaccine should desirably comprise more than one virus, e.g. reovirus and adenovirus, and possibly contain an additional virus, such as Birna-like virus.
SUMMARY OF THE INVENTION
[0015] The invention provides a method of vaccinating against disease conditions associated with Avian Malabsorption Syndrome (MAS), which comprises administering to a poultry specimen a vaccine containing avian reovirus and avian adenovirus.
[0016] In a further embodiment, the invention provides a vaccine against disease conditions associated with MAS which comprises avian reovirus and avian adenovirus in a pharmaceutically acceptable carrier.
[0017] The invention also provides a method of producing a vaccine against Avian Malabsorption Syndrome, which comprises isolating suitable specimens of avian reovirus and avian adenovirus, and then incorporating the isolated viruses with a pharmaceutically acceptable carrier into a vaccine.
[0018] A combination vaccine against Avian Malabsorption Syndrome is also set forth. The vaccine contains about 10 4 -10 10 TCID 50 of inactivated avian reovirus and about 10 4 -10 10 TCID 50 of inactivated avian adenovirus. The vaccine can also contain one or more additional viruses associated with poultry disease, such as the Birna-like virus, which produces some symptoms that are similar to those produced by MAS.
[0019] A combination vaccine against Avian Malabsorption Syndrome can also contain live viruses. In this embodiment, there is provided a vaccine against MAS comprising about 10 2 -10 9 TCID 50 of live avian reovirus and about 10 2 -10 9 TCID 50 of live avian adenovirus. The live viruses are desirably attenuated. This version of the vaccine can also contain additional viruses as well, such as the aforementioned Birna-like virus in live, and preferably attenuated form.
[0020] The foregoing and other features and advantages of the invention will become more apparent from the detailed description of the preferred embodiments of the invention given below.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The invention provides an avian vaccine against MAS disease conditions containing at least two avian viruses. Preferably, these viruses are the reovirus and the adenovirus.
[0022] The avian reovirus and adenovirus utilized in the vaccine as part of the invention can be used in a live, live attenuated or inactivated form. The invention provides in a further aspect a vaccine for use in the protection of poultry against disease conditions resulting from an avian reovirus and adenovirus infection, such as enteric disease conditions observed with MAS, comprising an avian reovirus and adenovirus according to the invention and a pharmaceutical acceptable carrier or diluent.
[0023] The avian reovirus and adenovirus according to the present invention can be incorporated into the vaccine as a live attenuated or inactivated virus. The property of the avian reovirus and adenovirus to induce MAS-associated disease conditions as described above are significantly reduced or completely absent if the avian reovirus and adenovirus are in a live attenuated or inactivated form. Attenuation of an avian reovirus and adenovirus according to the invention can be achieved by methods available in the art for this purpose, such as disclosed in Gouvea et al. (Virology 126, 240-247, 1983). Briefly, after the isolation of the virus from a target animal, a virus suspension is inoculated onto primary chicken embryo fibroblasts (CEFs). If the isolate is not able to produce CPE, then the virus is passaged repeatedly (e.g. about 3-10 times) until CPE is observed. As soon as CPE is visible, cells and cell culture fluids are collected, frozen and thawed, clarified by centrifugation and the supernatant containing the avian reovirus isolate is aliquoted and stored at −20° C. This process may be repeated (e.g. about 10-100 times) to further attenuate the virus.
[0024] A vaccine according to the invention can be prepared by available methods, such as for example the commonly used methods for the preparation of commercially available live- and inactivated virus vaccines. The preparation of veterinary vaccine compositions is inter alia described in “Handbuch der Schutzimpfungen in der Tiermedizin” (eds.: Mayr, A. et al., Verlag Paul Parey, Berlin und Hamburg, Germany, 1984) and “Vaccines for Veterinary Applications” (ed.: Peters, A. R. et al., Butterworth-Heinemann Ltd., 1993). Briefly, a susceptible substrate is inoculated with an avian virus according to the invention in a live or live attenuated form, and propagated until the virus replicated to a desired infectious titre or antigen mass content after which virus-containing material is harvested and formulated to a pharmaceutical composition with prophylactic activity.
[0025] Substrates which can support the replication of the avian viruses defined above, if necessary after adaptation of the avian viruses to a substrate, can be used to produce a vaccine according to the present invention. Suitable substrates include primary (avian) cell cultures, such as chicken embryo liver cells (CEL), chicken embryo fibroblasts (CEF) or chicken kidney cells (CK), mammalian cell lines such as the VERO cell line or the BGM-70 cell line, or avian cell lines such as QT-35, QM-7, LMH or JBJ-1. Typically, after inoculation of the cells, the virus is propagated for about 3-10 days, after which the cell culture supernatant is harvested, and, if desired, filtered or centrifuged in order to remove cell debris.
[0026] Alternatively, the viruses as part of the vaccine according to the invention can be propagated in embryonated chicken eggs, followed by harvesting the virus material by routine methods. The vaccine according to the invention containing the live attenuated virus can be prepared, shipped and sold in a (frozen) suspension or in a lyophilised form. The vaccine additionally contains a pharmaceutically acceptable carrier or diluent customarily used for such compositions. Carriers include stabilizers, preservatives and buffers. Suitable stabilizers include but are not limited to SPGA, carbohydrates (such as sorbitol, mannitol, starch, sucrose, dextran, glutamate, glucose or inositol), proteins (such as dried milk serum, albumin or casein) or degradation products thereof, including gelatin. Suitable buffers are, for example, alkali metal phosphates. Suitable preservatives are thimerosal, merthiolate and gentamicin. If desired, the live vaccines according to the invention may contain an adjuvant. Examples of suitable compounds and compositions with adjuvant activity are the same as mentioned below for the preparation of inactivated vaccines.
[0027] Although administration by injection, e.g., via the intramuscular, or subcutaneous route, of the live vaccine according to the present invention is possible, the live vaccine is preferably administered by the inexpensive mass application techniques commonly used for avian vaccination. These techniques include drinking water and spray vaccination, for example. Alternative methods for the administration of the live vaccine include in ovo, eye drop and beak dipping administration.
[0028] Typically, the live-vaccine according to the invention can be administered in a combined dose of about 10 2 -10 9 TCID 50 of avian reovirus and about 10 2 -10 9 TCID 50 of avian adenovirus per bird, preferably in a dose ranging from about 10 2 -10 6 TCID 50 of avian reovirus and about 10 2 -10 6 TCID 50 of avian adenovirus per bird. As that term is used herein, “TCID 50 ” refers to “50% Tissue Culture Infectious Dose.”
[0029] Although, the avian reovirus and adenovirus vaccine according to the present invention may be used effectively in chickens, other poultry such as turkeys, ducks, geese, guinea fowl, pigeons, quail and bantams may also be successfully vaccinated with the vaccine. Chickens include broilers, reproduction stock and egg-laying stock. Because disease conditions observed with MAS have been reported primarily in broiler chickens, the present invention preferably provides a vaccine for use in the protection of broilers against such disease conditions.
[0030] In another preferred embodiment, the present invention also provides a vaccine against MAS disease conditions comprising the avian reovirus and adenovirus in an inactivated form. The major advantage of an inactivated vaccine is the obtention of elevated levels of protective antibodies of long duration. This property makes an inactivated vaccine particularly suitable for breeder vaccination.
[0031] The aim of inactivation of the viruses harvested after the propagation step is to eliminate reproduction of the viruses. In general, this can be achieved by chemical or physical means. Chemical inactivation can be effected by treating the viruses with, for example, enzymes, formaldehyde, β-propiolactone, ethylene-imine or a derivative thereof, as well as other compounds available in the art. If necessary, the inactivating compound is neutralized afterwards. Material inactivated with formaldehyde can, for example, be neutralized with thiosulphate. Physical inactivation can also be carried out by subjecting the viruses to energy-rich radiation, such as UV light or γ-rays. If desired, after treatment the pH can be adjusted to a value of about 7.
[0032] A vaccine containing the inactivated avian reovirus and adenovirus can, for example, comprise one or more of the above-mentioned pharmaceutically acceptable carriers or diluents suited for this purpose. Preferably, an inactivated vaccine according to the invention comprises one or more compounds with adjuvant activity. Suitable compounds or compositions for this purpose include aluminum hydroxide, -phosphate of -oxide, oil-in-water or water-in-oil emulsions based on, for example a mineral oil, such as Bayol F® or Marcol 52®, or a vegetable oil, for example those containing vitamin E acetate, and saponins.
[0033] Inactivated vaccines are usually administered parentally, e.g. intramuscularly or subcutaneously, but other methods available in the art may be contemplated as well. The vaccine according to the invention comprises an effective dosage of the avian reovirus and adenovirus as the active component, i.e., an amount of immunizing avian reovirus and adenovirus material that will induce immunity in the vaccinated birds or their progeny against challenge by a virulent virus. Immunity is defined herein as the induction of a significantly higher level of protection in a population of birds after vaccination compared to an unvaccinated group.
[0034] An inactivated vaccine may contain the combined antigenic equivalent of about of 10 4 -10 10 TCID 50 of avian reovirus and about 10 4 -10 10 TCID 50 of avian adenovirus per bird.
[0035] The age of the animals receiving a live or inactivated vaccine according to the various embodiments of the invention is the same as that of the animals receiving the presently commercially available live-or inactivated avian reovirus vaccines. For example, broilers may be vaccinated directly from one-day-old onwards with the live attenuated vaccine according to the invention. Vaccination of parent stock, such as broiler breeders, can be done with a live attenuated or inactivated vaccine according to the invention or combinations of both. The advantages of this type of immunization program includes the immediate protection of one-day-old progeny provided by maternally derived antibodies vertically transmitted to the young birds. A typical breeder vaccination program includes the vaccination of the breeders at 6-weeks of age with a live attenuated vaccine, followed by a vaccination between 14-18 weeks of age with an inactivated vaccine. Alternatively, the live vaccination may be followed by two vaccinations with inactivated vaccines on 10-12 weeks and 16-18 weeks of age. Other methods of vaccination include in ovo administration according to methods available in the art.
[0036] The invention also includes other combination vaccines comprising, in addition to the avian reovirus and avian adenovirus according to the invention, one or more vaccine components of other pathogens infectious to poultry. With such other pathogens infectious to poultry also avian reoviruses and adenoviruses are meant which may be antigenically distinct from the avian reoviruses and adenoviruses according to the present invention, and include the avian reovirus strains associated with tenosynovitis, for example.
[0037] Preferably, the vaccine components in the combination vaccine are the live attenuated or inactivated forms of the pathogens infectious to poultry. In particular, the present invention provides a combination vaccine wherein all of the vaccine components are in an inactivated form.
[0038] Preferably, the combination vaccine comprises one or more vaccine strains of Birna-like disease virus, infectious bronchitis virus (IBV), Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), fowl adenovirus (FAV), EDS virus and turkey rhinotracheitis virus (TRTV). Birna-like disease virus may be especially suitable since although it does not appear to cause MAS, many of its symptoms are similar to or may contribute to manifestations associated with the primary disease.
EXAMPLES
[0039] The following examples are provided by way of illustration only, and should not be construed as limiting the scope of the invention.
[0040] The occurrence of MAS in layer replacement chicks in the Netherlands was confirmed by transmission of the disease through inoculation of 30 one-day old broiler chicks into the crop with homogenized intestines from affected birds from the field.
[0041] Inoculated chicks kept in isolation showed impaired growth until four weeks past infection. Birds produced mucous yellowish droppings and at post mortem thin liquid intestinal contents were found. Biochemical examination of blood samples showed low plasma carotenoid concentrations and increased alkaline phosphatase activity. Bone abnormalities were observed in infected chicks at the age of 15 and 28 days. Reovirus and adenovirus were isolated on chicken embryo fibroblasts (CEF) and on chicken kidney (CK) cells from intestines and livers from experimentally infected chicks. These viruses were identified using electron microscopy of the cell cultures from livers and intestines from experimentally infected chicks. An unidentified virus-like particle of about 65 nm was detected by electron microscopy in cell cultures.
[0042] The following terms and abbreviations are used throughout the following examples:
ALP: Plasma Alkaline Phosphatase activity ELISA: Enzyme—Linked Immunosorbent Assay HI: Haemagglutinating Inhibition MAS: Malabsorption syndrome PAGE: Poly-acrylamide-gel electrophoresis PBS: Phosphate—buffered saline
EXAMPLE 1
Materials and Methods
[0049] The innoculum was prepared from intestines (including duodenum and caecum), sampled from 10 chicks from the field showing clinical signs of MAS disease conditions. The intestines were stored at −20° C. One hundred grams of these intestines were homogenized into 100 ml of PBS using a laboratory blender. This homogenate (50% w/v) was used to inoculate one-day-old broiler chicks.
[0050] Eighty one-day-old broiler chicks were obtained from a commercial hatchery. The chicks were assigned to 2 groups of 40 birds housed in different isolators. The floor of the isolators was covered with paper, to enable observation of the droppings. Forty chicks (group 2) were inoculated with 0.5 ml of the intestinal homogenate by intubation into the crop. The other 40 chicks (group 1) were not inoculated and served as non-infected controls. The chicks were fed ad libitum with a commercial broiler feed and had free access to drinking water. They were not vaccinated against poultry diseases.
[0051] The chicks were observed daily for clinical signs of MAS. Abnormalities and mortality was recorded.
[0052] At days 3, 8, 15 and 28 after inoculation (post infection), a number of random birds (see Table 1) were weighed individually and killed. At post mortem, macroscopically bone disorders were assessed by the occurrence of alterations of the epiphyseal cartilage plates in the longitudinal sections of the proximal extremities of both tibiae of each bird.
[0053] Blood samples were taken individually in heparinised tubes after expiration of the chicks at days, 15 and 28 post infection. Blood plasma was stored at −20° C. until use. Carotenoid concentration (expressed as optical density of a petroleum ether extract) and alkaline phosphatase activity (expressed in Units per liter) was determined.
[0054] The presence of antibodies against reovirus was studied in blood sampled from chicks from group 2 (n=5) at day 28 post infection. Serology was done by using an AGP technique.
[0055] Livers, intestines and intestinal contents were collected from inoculated birds and from control birds at days 4, 8, 15 and 28 post infection after the birds were killed. The organs and intestinal contents sampled from chicks of the same group were pooled. The pooled samples were weighed and mixed with Duphar special cell culture medium (Gibco; cat. no. 041-90889; lot no 25 Q 5562) and homogenized by using a sterile laboratory blender. Portions of 1 to 4 ml of the homogenates were stored in labeled vials. To a part of the vials to be used for bacteriological examination, a mixture (3/1; v/v) of glycerine and f.c.s. (Gibco cat. no. 011-90002) was added. All vials were stored at −70° C. A selection of the homogenates was examined for the presence of viruses by inoculation of SPF eggs (CAM and allantois fluid), Chicken Embryo Fibroblasts (CEF), Chicken Kidney Cells (CKC). Another selection of the homogenates and cell cultures was examined for the presence of viruses by Electron Microscopy (EM).
[0056] Bacteriological examinations were performed on blood agar plates and on ABAP-plates under aerobic and anaerobic conditions on the inoculum used for infection of the chicks from group 2 and on homogenates prepared from intestines and livers sampled from chicks from group 1 (not infected controls) and chicks from group 2 (infected group) at days 4, 8, 15 and 28 post inoculation.
[0057] The parameters used in this experiment for diagnosing MAS were: growth retardation, yellowish mucous droppings, poor feathering, low plasma carotenoid concentration and high plasma alkaline phosphatase activity.
Results
[0058] All the chicks from group 2 showed clinical signs of MAS, 7 chicks died in the first week of life and 3 chicks died in the second week of life. The non-infected control chicks (group 1) developed normally and did not show clinical signs of any disease.
[0059] The mean body weights of chicks at different ages post infection are presented in Table 1 below. The inoculated chicks (group 2) had substantial lower mean body weights than the control chicks (group 1) of the same age. Bone disorders were found in 1 chick from group 2 at day 15 post infection and in 3 chicks from this group at day 28 post infection. The intestines from the chicks from group 2 were very pale and swollen with watery yellowish mucous contents. Pale livers were found in chicks of group 2.
[0000] TABLE 1 Mean body weight (BW), mean plasma alkaline phosphatase activity. (ALP) and mean plasma carotenoid concentration (CAR) at days 4, 8, 15 and 28 post infection Days post GROUP 1 GROUP 2 infection BW ALP CAR BW ALP CAR 4 58* n.d n.d 46* n.d. n.d. (8) (4) 8 129* n.d. n.d. 45* n.d. n.d. (16) (11) 15 386* 6382 1.18 88** 11462 0.118 (40) (1234) (0.15) (44) (1645) 28 1276* 2873 0.892 474*** 20566 0.500 (137) (789) (0.37) (171) (10960) (0.41) ALP: as Units per liter of plasma CAR: as optical density of petroleum ether extract Standard deviation (SD) in parenthesis number of chicks: *n = 10 **n = 6 ***n = 5
The mean values for alkaline phosphatase activity and carotenoid concentration in plasma samples taken from chicks at different ages post infection are presented in Table 1. The inoculated chicks (group 2) had substantial lower plasma carotenoid levels and substantial higher plasma alkaline phosphatase activities than the non infected controls of the same age.
[0060] No antibodies against reovirus were detected by AGP.
[0061] Adenovirus was isolated on chicken kidney cells from intestinal homogenates sampled from chicks of group 2 at days 8 (2 nd passage) and 15 ( 1st passage) after inoculation and from liver homogenate sampled from chicks from group 2 at day 15 after inoculation. Adenovirus was also isolated on Chicken embryo fibroblasts (2 nd passage) from liver homogenate sampled from chickens from group 2 at day 15 after inoculation.
[0062] Reovirus was isolated on Chicken kidney cells from intestinal homogenate and from intestinal homogenates sampled from chicks from group 2 (in 1st passage) on days 4, 8 and 28 after inoculation, reovirus was also isolated on chicken kidney cells (1 st passage) from livers of infected chicks sampled on days 4 and 28 post infection.
[0063] Virus-like particles of about 65 nm were detected by electron microscopy in cell cultures (Chicken kidney cells 2 nd passage; chicken embryo fibroblasts, 4 th passage) of livers obtained from chicks of group 2 at day 15 post inoculation. No viruses were isolated from the intestines and livers collected from the control birds.
[0064] Gram negative and gram positive bacteria (rods and cocci) were isolated aerobically and anaerobically on blood agar plates from the intestinal homogenates used for inoculation of the chicks of group 2 and also from homogenates prepared from intestines and livers sampled from chicks of groups 1 and 2 at days 4, 8, 15 and 28 post inoculation.
[0065] Following inoculation with intestinal material from affected birds from the field, the chicks from group 2 suffered from MAS. All chicks from this group showed severe clinical signs of this disease (impaired growth, bone disorders, poor feathering, low plasma carotenoid concentrations and elevated plasma alkaline phosphatase activities). This observation confirms the occurrence of MAS in layer replacement birds.
[0066] In contrast to previous work (Vertommen et. al; Avian Pathology 9:133-142), infected chicks died from MAS in this experiment.
[0067] Reovirus and adenovirus were isolated from intestinal homogenates and from liver homogenates originating from infected chicks. These viruses were not isolated from the control chicks. This observation appears to demonstrate that these viruses were not transmitted by the chicks used in this experiment, but originated from the intestinal homogenate used to inoculate these chicks.
[0068] The bacteriological results, however, revealed that the liver homogenates contained gram negative bacteria of intestinal origin. This finding suggests that the livers became contaminated with intestinal contents at sampling. This means that the viruses isolated from liver homogenates probably were of intestinal origin and did not result from multiplication in the liver. The AGP test did not demonstrate antibodies against reovirus. This observation does not exclude seroconversion because the AGP test only detects precipitines. Interesting are the virus-like particles of about 65 nm, detected by electron microscopy in cell cultures. Photographs of these particles were taken, but for identification further electron microscopy examinations were needed.
EXAMPLE 2
[0069] The objective of this study was to investigate whether the infectious agent or agents which are responsible for transmitting MAS spread via the peripheral blood. This was done by inoculating into the crop of one-day old broilers with homogenates of pancreas, yolk sac and liver originating from infected chicks.
[0070] Twenty one-day-old broiler chicks (Group 1) were inoculated by intubation into the crop with 0.5 ml of intestinal homogenate (stored at −70° C.) and then housed on the floor on a bedding of wood shavings. The chicks were killed on day 4 after inoculation. Livers, pancreas, yolk sac and intestines were carefully removed to avoid contamination with intestinal material. The intestines were stored at −70° C. Livers, pancreases and yolk sacs were homogenized. These homogenates were used to inoculate three new groups (Group 2, 3 and 4) of 20 one-day-old broiler chicks each by intubation into the crop. These groups were housed in different rooms in rings on the floor with a bedding of wood shavings. They were fed a commercial broiler feed and had free access to drinking water during the whole experimental period.
[0071] On days 5 and 21 after inoculation, chicks from each group were weighed and killed.
[0072] Bone disorders were assessed macroscopically by the occurrence of alterations of the epiphyseal cartilage plates in the longitudinal sections of the proximal extremities of both tibiae of each bird. Livers, pancreas and yolk sacs were collected. Crops were collected from chicks that had been infected with pancreas homogenate (group 4). The samples were stored at −70° C. for virus isolation. Plasma alkaline phosphatase activity was determined in blood sampled on day 21 post infection.
[0073] Infected chicks developed clinical signs of MAS, i.e., growth retardation, bone abnormalities, yellowish mucous droppings, elevated serum ALP activity etc. This indicates that the infectious agent or agents which is/are responsible for transmitting MAS spread from the intestines through the peripheral blood to other organs soon after infection.
[0074] Clinical signs of MAS were most pronounced in chicks which had been inoculated with pancreas homogenate (Group 4) suggesting that the amount of infectious agent(s) per organ differs.
[0075] Antibodies against reovirus and adenovirus were not detected in serum sampled on day 21 after infection.
[0076] From the results, it was concluded that: MAS can be transmitted through inoculation of one-day old broilers into the crop with homogenates of intestines, liver, yolk sac and pancreas originating from infected chicks. The agent or agents which are responsible for transmitting MAS: can be stored at −70° C. for several months, spread from the intestine of orally infected chicks to the pancreas, the liver and the yolk sac within 5 days after infection of the chicks. The amount of agent or agents which are responsible for transmitting MAS differs in the various organs and is probably the highest in the pancreas. These results indicated that the role of reovirus and adenovirus in MAS should be further investigated.
Materials and Methods
[0077] Twenty one-day-old broiler chicks were purchased from a commercial hatchery. The chicks were inoculated with 1.0 ml of intestinal homogenate by intubation into the crop and then housed in a ring (0.80 square meters floor space) on the floor on wood shavings. On days 4 and 21 after inoculation chicks from group 1 were killed. At post mortem, macroscopically bone disorders were assessed by the occurrence of alterations of the epiphyseal cartilage plates in the longitudinal sections of the proximal extremities of both tibiae of each bird. Livers, pancreas, yolk sac and intestines of these chicks were carefully removed to avoid contamination with intestinal material. The samples were stored at −70° C.
[0078] Homogenates were prepared from the livers, pancreas and yolk sacs collected from group 1 on day 4 after inoculation. These homogenates were used to inoculate three new groups (Group 2, 3 and 4) of 20 one-day-old broiler chicks by intubation into the crop.
[0079] Group 2 was inoculated with 1.0 ml of liver homogenate, Group 3 with 1.0 ml of yolk sac homogenate and Group 4 with 0.6 ml of pancreas homogenate. The groups were housed in different rooms in rings (0.80 square meter) on the floor on wood shavings. The chicks were fed a commercial broiler feed and had free access to drinking water during the whole experimental period.
[0080] On days 5 and 21 after inoculation, chicks from groups 2, 3 and 4 were weighed and killed, and macroscopic bone disorders were assessed by the occurrence on alterations of the epiphyseal cartilage plates in the longitudinal sections of the proximal extremities of both tibiae of each bird. Livers, pancreas and yolk sacs were collected. From the chicks from group 4 also crops were collected. The samples were stored at −70° C.
Time Table
[0000]
Day 1: Inoculation of Group 1: Twenty one-day old broilers with intestinal homogenate.
Day 4: 10 chicks from Group 1 were killed, followed by post mortem examination. Day 4 post infection: Sampling of liver, yolk sac and pancreas
Day 4: Inoculation of Group 2 with liver homogenate, Group 3 with yolk sac homogenate
Day 4 post infection: and Group 4 with pancreas homogenate.
Day 9: 10 chicks from Groups 2 and 3 and 5 chicks from Group 4 were killed, followed by post mortem examination. Sampled for virus isolation: liver, intestines, pancreas and yolk sac.
Day 21: 9 chicks from Group 1 were killed, followed by post mortem examination.
Day 21 post infection
Day 24: 9 chicks from Group 2 and 10 chicks from Groups 3 and
Day 21 post infection 4 were killed, followed by post mortem examination. Sampled for virus isolation: liver, intestines, pancreas and yolk sac. From Group 4 also crop. Blood samples taken for determination of ALP and antibodies against reovirus and adeno (BC14) virus.
[0090] The intestinal homogenate used to infect the chicks from group 1 was the same as used in the first experiment (Example 1). It was prepared from intestines (including duodenum and calcium), sampled from 10 chicks from the field showing clinical signs of MAS after the birds were killed. The intestines were stored at −20° C. One hundred grams of these intestines were homogenized into 100 ml of PBS using a laboratory blender. This homogenate was stored at −70° C.
[0091] The liver homogenate used to inoculate the chicks from group 2 was prepared from livers collected from chicks from group 1 on day 4 after infection of these chicks. The livers were homogenized in PBS (50% w/v).
[0092] The yolk sac homogenate used to inoculate the chicks from group 3 was prepared from yolk sacs collected from chicks from group 1 on day 4 after infection of these chicks. The yolk sacs were homogenized in PBS (50% w/v).
[0093] The pancreas homogenate used to inoculate the chicks from group 4 was prepared from pancreases collected from chicks from group 1 on day 4 after infection of these chicks. The pancreases were homogenized in PBS (20% w/v).
[0094] The chicks were observed daily for clinical signs of MAS. Abnormalities and mortality were recorded. Chicks from groups 2, 3 and 4 were weighed at an age of 5 and 21 days. The chicks from group 1 were weighed at an age of 21 days. The parameters used for diagnosing MAS were: growth retardation, yellowish mucous droppings, poor feathering, bone abnormalities and high plasma alkaline phosphatase activity.
[0095] Blood samples were taken individually in heparinised tubes after the chicks from groups 1, 2, 3 and 4 at day 21 post infection were killed. Blood plasma was stored at 4° C. until use. Alkaline phosphatase activity (expressed in Units per liter) was determined at the Animal Health Institute in Deventer, the Netherlands.
[0096] The presence of antibodies against reovirus and adenovirus was studied in blood sampled from chicks from groups 1, 2, 3 and 4 on day 21 post infection. Serology was done using HI and ELISA techniques.
[0097] Livers, intestines, yolk sac and pancreas were collected on days 5 and 21 post infection. The samples were stored at −70° C. A selection of the homogenates was examined for the presence of viruses by inoculation of Chicken Embryo Fibroblasts (CEF) and Chicken Kidney Cells (CKC).
[0098] Chicks from groups 1, 2 and 4 showed severe clinical signs of MAS. Five chicks from group 4 died on the day after inoculation. These chicks had swollen caeca and some chicks had blood in the crop. The mean body weights of chicks on day 21 post infection are presented in Table 2. The body weights of the infected chicks were below the standard of 800 grams. Bone abnormalities were found in chicks from groups 1, 2, 3 and 4. Bone abnormalities were most pronounced in chicks from groups 1 and 4. In these chicks not only abnormalities of the epiphysial cartilage plates of the proximal tibiae of both legs were found but also hyaline enlarged capitulae and tuberculae costarum. The intestines of chicks from groups 1 and 4 were very pale and swollen with watery yellowish mucous contents. In chicks from group 3 only moderate bone disorders were found while no abnormalities were found in the intestines of these chicks.
[0099] The mean values for alkaline phosphatase activity in plasma samples taken from chicks on 21 days post infection are presented in Table 2. The plasma alkaline phosphatase activities were substantially higher than expected (standard 3.000-6.000 U/L at 21 days of age).
[0000]
TABLE 2
Mean body weight and Plasma Alkaline
Phosphatase activity (ALP)on day 21
MEAN BODY
GROUP
WEIGHT IN
MEAN ALP (U/L)
BONE
(homogenate)
GRAMS (SD)
(SD)
DISORDERS
1 (INTESTINE)
686 (82)
11.916 (5.922)
Severe
2 (liver)
710 (104)
17.304 (6.925)
Severe
3 (yolk sac)
718 (68)
13.525 (8.962)
Slight
4 (pancreas)
600 (80)
16.458 (9.742)
very severe
[0100] No antibodies against reovirus and adenovirus (BC14) were detected.
Results
[0101] In this experiment MAS was transmitted by inoculation of one-day old broilers into the crop with homogenates of intestines, livers, yolk sac and pancreas. Infected chicks developed clinical signs of MAS, i.e., growth retardation, bone abnormalities, yellowish mucous droppings, elevated serum ALP activity etc. Clinical signs of MAS were the most pronounced in chicks which had been infected with intestinal homogenate (Group 1) and in chicks infected with pancreas homogenate (Group 4). The intestinal homogenate used to infect the chicks of Group 1 had been stored at −70° C. for several months before use. This shows that the infectious agent or agents which are responsible for transmitting MAS can be stored at −70° C.
[0102] MAS was transmitted through inoculation of chicks with homogenates of liver, yolk sac and pancreas. These homogenates were prepared from materials which were obtained from chicks on day 5 after oral infection with intestinal homogenate. This indicates that the infectious agent or agents which are responsible for transmitting MAS spread from the intestines to other organs soon after infection. Clinical signs of MAS were most pronounced in chicks which had been inoculated with pancreas material (Group 4). Chicks from this group also showed lesions in the crop and several chicks died shortly after infection. Clinical signs of MAS were less pronounced in chicks from the other groups. This observation suggests that the amount of infectious agent per organ differs.
[0103] Clinical signs of MAS observed during this experiment were less severe than those observed during the previous experiment (Example 1). This was probably due to the difference between the experiments in housing of the chicks. In this experiment, chicks were housed in rings with a bedding of wood shavings on the floor. In the experiment from Example 1, the chicks were kept in isolators on a floor covered with paper. In this case the chicks are in continuous contact with fresh droppings. This continuous contact of chicks with fresh feces seems to be essential for optimal development of clinical signs of MAS.
[0104] Reovirus was isolated from the pancreas of chicks from Group 4 but antibodies against this virus were not detected by ELISA in serum sampled on day 21 after infection. No antibodies to adenovirus (BC14) were detected by the HI test. This does not exclude adenoviruses as a responsible agent for MAS because only one serotype was tested.
EXAMPLE 3
[0105] Fifty one-day-old broiler chicks were assigned to 5 groups of 10 chicks and inoculated by intubation into the crop as follows: Group 1 (infected controls) with intestinal homogenate; Group 2 (reovirus) with 10 6.7 TCID 50 reovirus; Group 3 (adenovirus) with 10 8.2 TCID 50 adenovirus; Group 4 (adenovirus and reovirus) with a combination of 10 6.7 TCID 50 reovirus and 10 8.2 TCID 50 adenovirus. Group 5 (non-infected controls) was not inoculated. Each group was housed in a separate animal room on a stainless steel cage with a wire floor and a device to collect feces. On days 14 and 22 after inoculation, chicks from each group were weighed and killed.
[0106] Bone disorders were assessed macroscopically by the occurrence of alterations of the epiphyseal cartilage plates in the longitudinal sections of the proximal extremities of both tibiae of each bird. Intestines including pancreas were collected and stored at −70° C. for virus isolation. Plasma Alkaline Phosphatase activity was determined in blood sampled on day 22 post infection.
[0107] Antibodies against reovirus and adenovirus were not detected in serum sampled on day 22 after infection.
[0108] Infection of day-old chicks with adenovirus, reovirus and a combination of these viruses resulted in growth retardation, MAS-like clinical signs and bone disorders, but did not result in an increase of Plasma Alkaline Phosphatase activity. Clinical signs and bone disorders were most severe in chicks of group 1.
[0109] On day 22 post infection, mean body weight (667 grams) of chicks of group 4 was comparable with the mean body weight of the infected controls (group 1; 560 grams) but differed substantially from the mean body weights of chicks of groups 3 (reovirus, 837 grams) and 5 (uninfected controls, 913 grams).
[0110] From these results, it was concluded that MAS was partially reproduced by infection of chicks with adenovirus, reovirus and a combination of these viruses.
[0111] Fifty one-day-old broiler chicks obtained from a commercial hatchery were assigned to 5 groups of 10 chicks and inoculated by intubation into the crop with the following inoculae:
Group 1(infected controls): 0.5 ml. of intestinal homogenate; Group 2 (reovirus): 0.5 ml: containing 10 6.7 TCID 50 reovirus; Group 3 (adenovirus): 0.5 ml: containing 10 8.2 TCID 50 adenovirus; Group 4 (adenovirus and reovirus): 1.0 ml of a combination: containing 10 6.7 TCID 50 reovirus and 10 8.2 TCID 50 adenovirus; Group 5 (not infected controls): not inoculated.
[0117] Each group was housed in a separate animal room on a stainless steel cage with wire floor (0.5 m 2 ) and a device to collect feces. The floor of the cages was covered with paper to allow contact of the birds with fresh droppings. The chicks were ad libitum fed with a commercial broiler mash (CAVO-LATUCO) and had free access to drinking water provided through cups. Chicks were daily observed for clinical signs of MAS. On days 14 and 22 post infection, chicks from each group were individually weighed and killed. At post-mortem, macroscopic bone disorders were assessed by determining the occurrence of alterations of the epiphysial cartilage plates in the longitudinal sections of the proximal extremities of both tibiae of each bird. Intestines and pancreases were collected and stored at −70° C. Blood samples were taken from chicks from each group on day 22 post infection. Alkaline Phosphatase activity was determined in these blood samples.
[0000] Time table
[0000]
Day 0:
Inoculation of chicks.
Day 14:
Post-mortem examination on chicks from each group.
Collecting of intestines and pancreases.
Day 22:
Post-mortem examination on chicks from each group.
Collecting of intestines, pancreases and blood samples.
[0118] The intestinal homogenate used to infect the chicks from group 1 was the same as used in the first experiment (Example 1). It was prepared from intestines (including duodenum, pancreas and caecum) taken from 10 chicks from the field showing clinical signs of MAS.
[0119] The intestines were stored at −20° C. Hundred grams of these intestines were homogenized into 100 ml of PBS, using a laboratory blender. This homogenate was stored at −70° C.
[0120] The reovirus used to infect chicks from groups 3 and 4 originated from Example 1. It was isolated on chicken Kidney Cells (CKC) taken from infected controls. The virus was propagated on CKC before use in this experiment. The reovirus inoculum contained 10 7.0 TCID 50 per ml.
[0121] The adenovirus used to infect chicks from groups 2 and 4 originated from Example 1. It was isolated on Chicken Kidney Cells (CKC) from liver taken from infected controls. The virus was propagated on CKC before use in this experiment. The virus inoculum contained 10 8.5 TCID 50 per ml.
Methods
[0122] The chicks were observed daily for clinical signs of MAS. Abnormalities and mortality were recorded. Chicks from each group were weighed at 14 and 21 days. The parameters used for diagnosing MAS were: growth retardation, yellowish mucous droppings, poor feathering, bone abnormalities, paleness of blood plasma and shanks and high plasma Alkaline Phosphatase activity.
[0123] Blood samples were taken individually in heparinised tubes after chicks from each group on day 22 post infection were killed. Blood plasma was stored at 4° C. until use. Alkaline Phosphatase activity (expressed in Units per liter) was determined at the Animal Health Institute of the Netherlands.
[0124] The presence of antibodies against reovirus and adenovirus was determined in blood plasma sampled from chicks from each group on day 21 post infection. Serology was done at the Animal Health Institute, using HI and ELISA techniques.
[0125] Intestines and pancreases were taken from each group on days 14 and 22 post infection. Samples were stored at −70° C. A selection of homogenates was then examined for the presence of viruses by inoculation of Chicken Kidney Cells (CKC).
Results
[0126] Mean bodyweights, mean ALP and bone disorders observed at post-mortem are presented in Table 3A. Chicks of group 1 (infected controls) developed MAS and 2 chicks from this group that died had clinical signs of MAS. 2 Chicks from group 4 (adenovirus and reovirus) died with clinical signs of MAS (growth retardation, bone disorders, poorly pigmented). One Chick from group 2 (adenovirus) that died did not suffer from MAS. It died from pericarditis.
[0127] At post-mortem, bone abnormalities were found in chicks from groups 1, 2, 3 and 4 on days 14 and 22. On day 14 abnormalities were found in the epiphysial cartilage plates of the proximal tibiae. These were most severe in chicks from group 1 (infected controls).
[0128] On day 22, bone abnormalities were most pronounced in chicks from groups 1 (infected controls) and 4 (mixture of adenovirus and reovirus) In these chicks, abnormalities of the epiphysial cartilage plates of the proximal tibiae of both legs were found as well as hyaline enlarged capitulae and tuberculae costarum.
[0129] Chicks of groups 1 (infected controls) and 4 (mixture of adenovirus and reovirus) had pale shanks (most pronounced in the infected controls) on day 22 and blood plasma samples taken for the determination of plasma ALP activity were also very pale. All infected chicks had lower mean body weights than the controls (group 5) on days 14 and 22 post infection.
[0000]
TABLE 3A
Mean body weight, Plasma Alkaline Phosphatase activity (ALP) and bone disorders at different ages.
Increase in
mean body
weight
MEAN BODY WEIGHT IN
between
MEAN ALP
GRAMS
days 14 and
(U/L)
BONE DISORDERS
Day 14 post
day 22 post
22 post
day 22 post
day 14 post
Day 22 post
GROUP (homogenate)
infection.
infection
infection
infection
infection
infection
1 (INTESTINE)
277
550
273
14.440
Tibiae
Tibiae/ribs
severe
severe
2(adenovirus)
409
803
394
2318
Tibiae/
Ribs/
slight
moderate
3(reovirus)
389
837
448
2014
Tibiae/
Tibiae/
slight
slight
4(mix adenovirus and
380
667
287
2681
Tibiae/
Tibiae/ribs/
reovirus)
moderate
moderate
5 (uninfected controls)
468
913
445
2255
none
none
Clinical Chemistry
[0130] Mean values for Alkaline Phosphatase activity in plasma samples taken from chicks on 22 days post infection are presented in Table 3A. Mean plasma Alkaline Phosphatase activity of group 1 (infected controls) was 14.440 on day 22. This was substantial higher than the mean ALP values in the other groups (range 2.000-3.000).
[0131] No antibodies against adenovirus (EDS) using the HI test and no antibodies against reovirus using an ELISA test were detected in sera sampled on day 22 post infection.
[0132] Virus isolation was done on intestines (including pancreas) collected on day 14 post infection. The intestines were homogenized in PBS. (1:1, w/v). The results of virus isolation are summarized in Table 3B.
[0133] The virus titers determined were much lower than the titers of the inoculae used to infect the chicks at day-old. The virus titers must be carefully interpreted because the lowest dilutions could not be judged due to several factors (primary cells, intestinal homogenates, minor cpe). Although the titrations were continued on new monolayers, this procedure might have influenced the values of the titers.
[0134] The viruses isolated from groups 1, 2 and 3 were identical to those used to infect these chicks at day-old. This was also the case in group 4. But in this group virus isolation was not consistent In the qualitative test cell culture was overgrown by reovirus.
[0000]
TABLE 3B
Results of virus isolation from intestines sampled on day 14.
Results of virus isolation
10 log (TCID 50 )/ml
Mean
GROUP
of inoculae
10 log
10 log
(homogenate)
used on day 1.
Qualitative
(TCID 50 )/ml
(TCID 50 )/ml
1 (INTESTINE)
Reovirus
reovirus
4.8
5.05
4.80
4.88 ± 0.14
2(adenovirus)
7.0 adenovirus
adenovirus
adenovirus
4.80
4.43
n.d.
4.64 ± 0.19
3(reovirus)
8.5 reovirus)
Reovirus
reovirus
4.68
4.55
n.d
4.62 ± 0.009
4(mix adenovirus
7.0 adenovirus
Reovirus and
adenovirus 2
and reovirus)
8.5 reovirus
possibly
4.18
4.43
n.d.
4.31 ± 0.18
adenovirus 1
1 Cell culture was overgrown by reovirus. adenovirus was masked.
2 Cell culture was overgrown by adenovirus. reovirus was masked.
Discussion
[0135] Infection of day-old chicks with adenovirus, reovirus and a combination of these viruses resulted in growth retardation, MAS-like clinical signs and bone disorders.
[0136] Group 4 (mixture of adenovirus and reovirus) was the most interesting because on day 22, mean body weight (667 grams) of chicks of this group was substantially lower than the mean body weights of chicks of groups 2 (adenovirus, 803 grams), 3 (reovirus, 837 grams) and 5 (uninfected controls, 913 grams);
the increase in bodyweight of chicks of chicks of this group was 287 grams between days 14 and 22. This was comparable with the increase in bodyweight (273 grams) of the infected controls (group 1); at post-mortem, these chicks showed alterations of the epiphysial cartilage plates in both tibiae and hyaline enlarged capitula costarum. This was also seen (be it more severe) in infected controls. chicks of this group were poorly pigmented and sera collected on day 22 post infection were very pale.
In contrast with the infected controls (group 1), Plasma Alkaline Phosphatase activities were not increased in chicks infected with adenovirus, reovirus or a combination of these viruses. Therefore, it was concluded that not all symptoms of MAS were reproduced by infection of chicks with these virus isolates.
EXAMPLE 4
[0140] Twenty (20) one-day-old broiler chicks obtained from a commercial hatchery were assigned to 4 groups of 5 chicks and inoculated by intubation into the crop with 0.5 ml of inoculum per chick.
[0141] Groups were housed in isolators. Chicks were ad libitum fed and had free access to drinking water. They were daily observed for clinical signs of MAS. On day 14 post infection chicks were individually weighed, killed and post-mortem examined. Intestines (including) pancreases were collected and stored at ≦−60° C. and blood samples were taken for the determination of plasma Alkaline Phosphatase activity.
[0142] MAS was reproduced in chicks of group 3 (Infected controls; intestinal homogenate). The chicks infected with Birna-like virus (group 1) and the chicks (group 2) infected with a combination of Birna-like virus, adenovirus and reovirus did not develop MAS. They were very ill during the first week of life, then they recovered.
[0143] Most of these chicks were pale and showed moderate bone abnormalities at post-mortem examination on day 16 but their Plasma Alkaline Phosphatase activities were within normal ranges and their blood plasmas were yellow.
[0144] The results of the current experiment showed that the tested Birna-like virus can cause disease (diarrhea and some growth retardation) in young chickens—both singularly or in combination with adenovirus and reovirus—but not MAS.
[0145] From these results, it was concluded that the tested Birna-like virus appears not to be the causative agent of MAS. However, incorporation of the Birna-like virus into a vaccine containing the avian reovirus and avian adenovirus against MAS may be very desirable as a further embodiment of the invention.
Materials and Methods
[0146] Intestines were homogenized and stored at ≦−60° C. The intestinal homogenate used to infect the chicks from group 1 was the same as used in the first experiment (Example 1). It was prepared from intestines (including duodenum, pancreas and caecum) taken from 10 chicks from the field showing clinical signs of MAS.
[0147] The intestines were stored at −20° C. Hundred grams of these intestines were homogenized into 100 ml of PBS using a laboratory blender.
[0148] This homogenate was stored at ≦−60° C. The reovirus used to infect chicks from group 2 originated from Example 1. It was isolated on chicken Kidney Cells (CKC) according to Fort Dodge Animal Health protocols from intestines taken from infected controls. The virus was propagated on CKC and stored at ≦−60° C. before use in this experiment. The reovirus inoculum contained 10 6.7 TCID 50 reovirus per 0.5 ml.
[0149] The adenovirus used to infect chicks from group 2 originated from Example 1. It was isolated on chicken Kidney Cells (CKC) from liver taken from infected controls. The virus was propagated on CKC and stored at ≦−60° C. before use in this experiment. The inoculum contained 10 8.2 TCID 50 adenovirus per 0.5 ml.
[0150] The Birna-like virus was isolated from the intestinal homogenate that was used to infect chicks in the previous experiment.
[0151] The homogenate was 1:40 diluted with Qt 35 -medium. This suspension was used to inoculate Qt 35 monolayers (7×10 4 cells/cm 2 ). CPE was seen approximately one month later. A second passage was then started. A Birna-like virus was observed under EM in the second passage the following week. The cell culture used to infect the chicks in the current experiment was obtained a few months later (second passage on Qt 35 monolayers of the material obtained a few months earlier).
[0152] Twenty (20) one-day-old broiler chicks were obtained from a commercial hatchery and assigned to 4 groups of 5 chicks and inoculated by intubation into the crop with 0.5 ml of inoculum as shown in Table 4A.
[0000]
TABLE 4A
Specification of groups and inoculae.
COMPOSITION OF INOCULUM
GROUP
Per 0.5 ml/chick
Group 1
Birna-like virus
Second passage on Qt 35
n = 5
monolayers.
Group 2
Combination of adenovirus,
10 8.2 TCID 50, adenovirus;
n = 5
reovirus and Birna-like virus
10 6.7 TCID 50, reovirus;
Birna-like virus.
Group 3
Intestinal homogenate
originating from the
n = 5
infected controls from
Example 1.
Group 4
not infected controls
n = 5
[0153] Groups were housed in isolators. The floor of each isolator was covered with paper to allow contact of the birds with fresh droppings. The chicks were ad libitum fed with a commercial broiler mash (CAVO-LATUCO) and had free access to drinking water which was provided through cups. They were daily observed for clinical signs of MAS. On day 16 post infection, chicks from each group were individually weighed, killed and post-mortem examined. Intestines (including pancreases) were collected and stored at ≦−60° C. Blood samples were taken from all chicks after death. Plasma Alkaline Phosphatase activity was determined in the blood plasmas prepared from these blood samples.
[0000]
Day 0:
Inoculation of chicks.
Day 16:
Weighing all chicks
Post - mortem examination. Collecting intestines, pancreases and
bloodsamples.
[0154] Chicks were daily observed for clinical signs of MAS. Abnormalities and mortality were recorded. Chicks were weighed, killed and post-mortem examined on day 16. The parameters used for diagnosing MAS were: growth retardation, yellowish mucous droppings, poor feathering, bone abnormalities and high plasma Alkaline Phosphatase activity.
[0155] Blood samples were taken individually in heparinised tubes after chicks on day 16 post infection were killed. Plasma was prepared and examined for color (pale or yellow). Alkaline Phosphatase activity (expressed in Units per liter) was determined in these plasma samples at the Animal Health Institute in Deventer, the Netherlands.
[0156] Intestines and pancreases were collected from each group on day 21 post infection. Samples were stored at ≦−60° C.
Results
[0157] MAS was reproduced in the chicks infected with intestinal homogenate (infected controls; group 3). These chicks showed growth retardation, poor pigmentation, bone abnormalities, pale blood plasmas and elevated Plasma Alkaline Phosphatase activity. The chicks infected with Birna-like virus or with a mixture of Birna-like virus, adenovirus and reovirus were ill during the first week of life. But after the first week these chicks recovered. At post-mortem, pale intestines and moderate bone deformities were seen in these chicks.
[0158] Mean body weight at different ages and results of post-mortem examination on day 16 are summarized in Table 4B.
[0000]
TABLE 4B
Mean body weight (grams), Plasma Alkaline Phosphatase activity
(ALP) and results of post-mortem on day 16 post infection
Mean
bodyweight
Mean
in grams
ALP(U/I)
Plasma color
Results of
day 16 post
Day 16 post
day 16 post
post-mortem
Group
infection
infection
infection
day 21 post infection
1
422 ab
3904
Yellow
4/4 Chicks: pale breast.
Birna-like virus
2/4 Chicks: pale shanks.
2/4 Chicks: pale intestines.
2/4 chicks: Rib abnormalities
(slight)
1/4 Chicks: Tibial abnormalities
(slight).
2
374 b
6388
Yellow
5/5 Chicks: pale breast.
combination of Birna-
5/5 Chicks: pale shanks.
like virus; adenovirus
4/5 chicks: pale intestines.
and reovirus.
5/5 chicks: slight to moderate Rib
abnormalities.
4/5 chicks: moderate Tibial
abnormalities.
3
240 c
42143
very pale
4/4 chicks: pale breast.
Intestinal Homogenate
4/4 Chicks; very pale shanks.
4/4 chicks: very pale liver.
1/4 chicks: slight to moderate rib
abnormalities.
4/4 chicks; slight to severe tibial
abnormalities.
4
451 a
3822
Yellow
no abnormalities
Non infected controls
a,ab,c different annotations mean significant different mean body weight (p < 0.05)
[0159] The blood plasmas from group 3 (infected controls) were pale. The blood plasmas from groups 1 (Birna-like virus), 2 (combination of viruses) and 4 (non infected controls) were yellow. Plasma Alkaline Phosphatase activities of group 3 (infected controls) were substantially higher than plasma Alkaline Phosphatase activity of groups 1 (Birna-like virus), 2 (combination of viruses) and 4 (non infected controls). Results of examination of plasma on color and mean Alkaline Phosphatase activities are also presented in Table 4B.
[0160] MAS was reproduced in chicks of group 3 (Infected controls; intestinal homogenate). These chicks showed all clinical signs of the disease, i.e. stunting, pale shanks and blood plasma, elevated plasma Alkaline Phosphatase activity, bone abnormalities etc.
[0161] The chicks infected with the Birna-like virus (group 1) and the chicks (group 2) infected with a combination of Birna-like virus, adenovirus and reovirus were very ill during the first week of life, but then they recovered. Most of these chicks had pale shanks, pale muscle (breast) tissue and moderate bone abnormalities. They were not stunted and did not have pale blood plasmas. Plasma ALP values of groups 1 (Birna-like virus) and 2 (combination of Birna-like virus, adenovirus and reovirus; in 4/5 chicks) were in the same range as the plasma ALP values of group 4 (not infected controls). Chicks from group 2 had an ALP value of 14.060 U/I. The question about the reliability of this exception is somewhat difficult to assess. Is it a true value or is it due to contamination of the test material in the laboratory. Moreover, this value was much lower than the mean plasma ALP (42.143 U/L) in group 3. The results of the current experiment show that the tested Birna-like virus can apparently cause some significant disease conditions (diarrhea and some growth retardation) in young chickens—both singularly or in combination with adenovirus and reovirus—but apparently not MAS.
EXAMPLE 5
[0162] The objective of this study is to investigate the role of adenovirus and reovirus in MAS by inoculation of one day old chicks with intestinal material from chickens from Example 3.
[0163] 50 One-day-old broiler chicks obtained from a commercial hatchery were assigned to 5 groups of 10 chicks and inoculated by intubation into the crop with 0.5 ml of intestinal homogenates. The intestinal homogenates originated from infected chicks from Example 3.
Group 1: homogenate originating from Example 3 {Group 1 (infected controls)}; contained 10 4.9 TCID 50 reovirus per ml. Group 2: homogenate originating from Example 3 {Group 3 (adenovirus)}; contained 10 4.6 TCID 50 adenovirus per ml. Group 3: homogenate originating from Example 3 {Group 2 (reovirus)}; contained 10 4.6 TCID 50 reovirus per ml. Group 4: homogenate originating from Example 3 {Group 4 (adenovirus+reovirus)}; contained 10 4.3 TCID 50 adenovirus per ml and reovirus was present. Group 5: non-inoculated controls.
[0169] Groups were housed in separate animal rooms on stainless steel cages. Chicks were ad libitum fed and had free access to drinking water. They were daily observed for clinical signs of MAS. On days 6, 14 and 21 post infection, chicks were individually weighed.
[0170] On day 21 chicks were killed, post-mortem examined and intestines (including) pancreases were collected and stored at −70° C., and blood samples were taken for the determination of plasma Alkaline Phosphatase activity and antibody titres against adenovirus and reovirus.
[0171] The results of the current experiment were comparable to the results of the previous experiment (Example 3) on the role of reovirus and adenovirus in MAS.
[0172] MAS was reproduced in 3/10 chicks of group 1 (infected controls) and partially (bone disorders, pale swollen intestines, and poor pigmentation) in chicks of groups 2 (adenovirus), 3 (reovirus) and 4 (combination of adenovirus and reovirus).
[0173] The results of the current experiment indicate that MAS is a multifactorial disease caused by more than a single pathogen and that each of these pathogens is responsible for specific clinical signs of the disease.—i.e. stunted growth, poor pigmentation, bone disorders, yellowish mucous droppings and elevated Plasma Alkaline Phosphatase activity.
[0174] From the results, it was concluded that the tested adenovirus and reovirus are quite possibly involved in MAS, with adenovirus being responsible for poor pigmentation and the occurrence of bone abnormalities, and with reovirus being responsible for intestinal abnormalities. Another factor or factors is/are needed to induce yellowish mucous droppings, stunted growth and elevated plasma ALP activity. Thus, it appears that a vaccine containing at least these two viruses should be utilized to protect poultry against MAS disease conditions.
Materials and Methods
[0175] The inoculae used to infect chicks in the current experiment originated from Example 3. They were prepared from intestines (duodenum including pancreas) collected from the chicks of groups 1 (infected controls), 2 (infected with reovirus), 3 (infected with adenovirus) and 4 (infected with combination of adenovirus and reovirus) in Example 3 on day 21 post infection.
[0176] The intestines (pooled per group) were mixed (weight/weight 1:1) with PBS and homogenized using a laboratory blender. Virus titres were determined according to Fort Dodge Animal Health protocols. The homogenates were stored at −70° C. until the day they were used.
[0177] Fifty one-day-old broiler chicks obtained from a commercial hatchery were assigned to 5 groups of 10 chicks and as follows inoculated by intubation into the crop with 0.5 ml of intestinal homogenates:
[0000]
INOCULUM
VIRUS AND
GROUP
CODE
ORIGIN OF INOCULUM
TITRE (TCID 50 .)
Group 1
Ino 1
Example 3;
reovirus
(intestine)
Group 1
(10 4.9 ).
(infected controls)
Group 2
Ino 2
Example 3;
adenovirus
(Adeno)
Group 3
(10 4.6 )
(adenovirus)
Group 3
Ino 3
Example 3;
reovirus
(Reo)
Group 2
(10 4.6 )
(reovirus)
Group 4
Ino 4
Example 3;
{adenovirus
(Adeno + Reo)
Group 4
(10 4.3 )} +
(Adeno + reovirus)
reovirus
Group 5
non-
inoculated.
(controls)
[0178] Each group was housed in a separate animal room on a stainless steel cage with wire floor (0.5 m 2 )and a device to collect feces. The floor of the cages was covered with paper to allow contact of the birds with fresh droppings. The chicks were ad libitum fed with a commercial broiler mash (CAVO-LATUCO) and had free access to drinking water which was provided through cups. The chicks were daily observed for clinical signs of MAS. On days 6, 14 and 21 post infection, chicks from each group were individually weighed.
[0179] On day 21 chicks were killed, post-mortem examined and intestines (including) pancreases were collected and stored at −70° C. Blood samples were taken from chicks from each group on day 21 post infection. Antibody titres against adenovirus and reovirus were determined in these blood samples. Alkaline Phosphatase activity was determined in blood samples taken from chicks of groups 1, 4 and 5.
Time Table
[0000]
Day 0: Inoculation of chicks.
Day 6: Weighing of all chicks from each group.
Day 14: Weighing of all chicks
Day 21: Post mortem examination. Collecting of intestines, pancreases and blood samples.
[0184] The chicks were daily observed for clinical signs of MAS. Abnormalities and mortality were recorded. Chicks from each group were weighed at 6, 14 and 21 days old. The parameters used for diagnosing MAS were: growth retardation, yellowish mucous droppings, poor feathering, bone abnormalities and high plasma alkaline phosphatase activity.
[0185] Blood samples were taken individually in heparinised tubes after chicks from each group at day 21 post infection were killed. Blood plasma was stored at 4° C. until use. Alkaline phosphatase activity (expressed in Units per liter) was determined in blood samples from chicks of groups 1, 4 and 5.
[0186] The presence of antibodies against reovirus and adenovirus was determined in blood sampled from chicks from each group on day 21 post infection. Serology was done using HI and ELISA techniques.
[0187] Intestines and pancreases were collected from each group on day 21 post infection. Samples were stored at −70° C.
Results
[0188] The infected controls (group 1) developed MAS. All clinical signs of the disease (growth retardation, yellowish mucous droppings, poor feathering, bone abnormalities and high plasma alkaline phosphatase activity) were observed in these chicks. Growth retardation started in the first week of life.
[0189] Chicks of group 4 {Ino 4 (adenovirus and reovirus)} were very ill during the first week of life. 2 Chicks from this group died with clinical signs of MAS (growth retardation, pale and swollen intestines) during this period. These chicks also produced yellowish mucous droppings during this period.
[0190] Bone disorders were observed in 3/10 chicks of group 1 (Ino 1; infected controls), in 9/10 chicks of group 2 (Ino 2; adenovirus) and 8/8 chicks of group 4 (Ino 4; mixture of adenovirus and reovirus). These chicks had also very pale shanks.
[0191] Mean body weights of chicks from groups 2 (Ino 2, adenovirus), 3 (Ino 3, reovirus) and 4 was lower than the mean body weight of the non infected controls (group 5) at 6 days-old, but not at older ages.
[0192] Mean body weight at different ages and results of post mortem examination on day 21 are summarized in Table 5A. Summaries of Plasma Alkaline phosphates activity are given in Table 5C. Details of inoculum preparation are given below in “Inoculum Preparation Section”.
[0000]
TABLE 5A
Mean body weight, Plasma Alkaline Phosphatase activity
(ALP) and results of post-mortem on day 21
Mean
Mean bodyweight in grams
ALP(U/I)
Results of
Group
day 6 post
day 14 post
day 21 post
day 22 post
post-mortem
(homogenate)
infection
infection
infection
infection
day 21 post infection
1
81
230
461
29.718
Pale shanks;
(INO 1; INTESTINE)
pale swollen intestines;
n = 10
3/10 chicks with severe
bone disorders of tibiae
and ribs
2
130
403
727
n.d.
Pale shanks;
(Ino 2; adenovirus)
5/10 chicks with
n = 10
moderate bone disorders
of tibiae.
3
126
426
771
n.d.
Pale intestines; no bone
(Ino 3; reovirus)
abnormalities
n = 10
4
124
410
781
2550
2 chicks died in the first
(Ino 4; adenovirus and
week. These were runted
reovirus)
chicks.
n = 8
Pale shanks and pale
swollen intestines;
8/8 Chicks with moderate
to severe bone
abnormalities of tibiae.
5
154
471
691
3566
No abnormalities.
(uninfected controls)
n = 10
[0193] Mean values for alkaline phosphatase activity in plasma samples taken from chicks of groups 1, 4 and 5 on 21 days post infection are also presented in Table 5A.
[0194] Plasma alkaline phosphatase activity of the infected controls (group 1) was substantially higher than the plasma alkaline phosphatase activity of groups 5 (non-infected controls) and 4 {Ino 4 (mixture of adenovirus and reovirus)}, being comparable.
[0195] No antibodies against reovirus and adenovirus were detected in blood samples taken on day 21.
[0196] The results of the current experiment are comparable to the results of the previous experiment (Example 3) on the role of reovirus and adenovirus in MAS. In both experiments, MAS was partially reproduced after oral infection of chicks with adenovirus, reovirus and a combination of them. In the first experiment cell-cultured viruses (with high titres) were used. In the current experiment animal-passaged viruses (with relatively low titres) were used. This indicates that animal passaging of the viruses did not alter their potency and ability to reproduce MAS. This possibly means that these viruses only form a part of the syndrome.
[0197] The results of the current experiment (summarized in Table 5B) support this conclusion. They suggest that the clinical signs of MAS result from the combined action of several pathogens. They also suggest that each of these pathogens is responsible for specific clinical signs of the disease—i.e. stunted growth, poor pigmentation, bone disorders, yellowish mucous droppings and/or elevated Plasma Alkaline Phosphatase activity—and that a vaccine against MAS disease should be comprised of at least two of these pathogens.
[0000]
TABLE 5B
Summary of clinical signs.
Group 1
Group 2
Group 3
Group 4
Group 5
(Ino 1;
(Ino 2;
(Ino 3;
(Ino 4; adenovirus
(uninfected
Clinical sign
intestine)
adenovirus)
reovirus)
and reovirus)
controls)
Stunted growth
yes
No
no
retardation during
no
the first week
2 stunted chicks
died during the first
week.
Pale shanks
yes
Yes
no
yes
no
Pale swollen
yes
No
yes
yes
no
intestines
Bone disorders
yes
Yes
no
yes
no
3/10
10/10
8/8
Yellowish
yes
during the first
no
during the first week
no
mucous
week
droppings
ALP
yes
No
no
no
no
[0198] The results of the current experiment show that:
adenovirus is responsible for poor pigmentation and bone abnormalities; adenovirus can cause yellowish mucous droppings; reovirus is responsible for pale swollen intestines (in this experiment; in Example 3, reovirus also caused bone disorders). adenovirus and reovirus seem not to be responsible for elevated Plasma ALP; other additional factors seem to be responsible for this parameter. The results of this experiment are not conclusive about the role of adenovirus and reovirus in stunting. The 2 chicks from group 4 that died during the first week were stunted chicks. But the surviving chicks were not. Mean bodyweights of adenovirus and reovirus infected chicks (groups 2, 3 and 4) did not differ substantially from the mean bodyweight of the non infected controls (group 5) on day 21 post infection. This was in contrast to the results of Example 3 (first experiment on the role of adenovirus and reovirus in MAS). In that experiment, adenovirus and reovirus (both in cell-cultures) caused growth retardation.
[0204] The difference between Example 3 and the current experiment is possibly due to the much lower virus titers in the homogenates used in the current experiment.
[0205] Mean bodyweight of the non infected controls was 691 grams on day 21. This was lower than normal (760 grams) because these chicks were fed a low energetic pullet ration instead of a high energetic broiler feed during the last week.
[0206] From the results, it is concluded that the tested adenovirus and reovirus are very possibly involved in MAS, with adenovirus being responsible for poor pigmentation and the occurrence of bone abnormalities, and the reovirus being responsible for intestinal abnormalities and bone abnormalities. The results are not completely conclusive about stunted growth; another factor or factors may be needed to induce yellowish mucous droppings and elevated plasma ALP activity.
[0000]
TABLE 5C
Plasma alkaline phosphates activity (in U/L) on day 21
Group 4
Group 1
Group 2
Group 3
Ino 4
AGE IN
Ino 1
Ino 2
Ino 3
(Adeno and
Group 5
DAYS
(intestine
(Adeno)
(Reo)
Reo)
controls
21
33365
n.d.
n.d.
2162
4239
16602
2383
2978
17766
2887
2028
40872
2767
2865
39986
5720
n = 5
n = 4
n = 5
mean: 29718
mean: 2550
mean: 3566
s.d. 11811
s.d. 336
s.d. 1440
EXAMPLE 6
[0207] In the current experiment, the factor(s) was analyzed to determine whether it is bacteria, a virus or a protein. This was done through fractionating (centrifugation: low speed, high Speed and ultra) of intestinal homogenate, followed by infection of day-old broiler chicks with these fractions.
[0208] Thirty one-day-old broiler chicks obtained from a commercial hatchery were assigned to 6 groups of 5 chicks and inoculated by intubation into the crop with 0.5 ml of inoculum per chick.
[0000]
Specification of groups and inoculae.
GROUP
INOCULUM CODE
COMPOSITION OF INOCULUM
Group 1
fraction 1
Pellets after LS and HS. (Bacteria
and tissue)
Group 2
fraction 2
Supernatant after UC.
(Low molecular particles and
molecules).
Group 3
fraction 3
Pellet after UC (Viruses).
Group 4
fraction 4
Combination of pellet after Lsand HS,
pellet after UC and supernatant after UC.
(Reconstituted intestinal homogenate)
Group 5
Intestinal
homogenate
Group 6
not inoculated
LS = Low speed centrifugation
HS = High speed centrifugation
UC = Ultra centrifugation
[0209] Groups 1, 2, 3, and 4 were housed in isolators. Groups 5 and 6 in separate animal rooms on stainless steel cages. Chicks were ad libitum fed and had free access to drinking water. They were daily observed for clinical signs of MAS.
[0210] On day 14 post infection chicks were individually weighed, killed and post- mortem examined. Intestines (including) pancreases were collected and stored at ≦−60° C., and blood samples were taken for the determination of plasma Alkaline Phosphatase activity.
[0211] MAS was reproduced in chicks of groups 3 (fraction 3; mainly viruses), 4 (fraction 4, reconstituted intestinal homogenate), and 5 (fraction 5; intestinal homogenate). MAS was partially reproduced (bone disorders, and elevated ALP) in chicks of groups 1 (fraction 1; bacteria) and 2 (fraction 2; proteins, small molecules and small viruses).
[0212] The results of this experiment exclude bacteria as being the causative agent of MAS. Viruses are indicated because the syndrome was reproduced with the bacteria-free fraction 3. The results of this experiment did not totally exclude involvement of proteins, toxins or other small molecules because these were present in fraction 2 and 3. The involvement of these small molecules can be further investigated with electrophoresis techniques. From the results, it was concluded that MAS has a viral etiology. The possible role of low molecular particles and molecules might be further investigated by poly-acrylamide-gel electrophoresis (PAGE).
Materials and Methods
[0213] The inoculae used to infect chicks of groups 1, 2, 3 and 4 were prepared from intestines sampled from infected chicks of group 1 from Example 2. Intestines were homogenized and stored at ≦−60° C. until used in the current experiment. Homogenates were thawed and fractions prepared through Low-Speed (LS), High Speed (HS) and Ultra Centrifugation.(UC). The combined pellets after LS and HS, supernatant after UC and pellet after UC were used to infect chicks.
[0214] Thirty one-day-old broiler chicks obtained from a commercial hatchery were assigned to 6 groups of 5 chicks and inoculated by intubation into the crop with 0.5 ml of inoculum as shown in Table 6A.
[0000]
TABLE 6A
Specification of groups and inoculae.
GROUP
INOCULUM CODE
COMPOSITION OF INOCULUM
Group 1
Fraction 1
Pellets after LS and HS. (Bacteria
and tissue)
Group 2
Fraction 2
Supernatant after UC.
(Low molecular particles and
molecules).
Group 3
Fraction 3
Pellet after UC (Viruses).
Group 4
Fraction 4
Combination of pellet after LS and
HS, pellet after UC and
supernatant after UC.
(Reconstituted intestinal
homogenate)
Group 5
Intestinal homogenate
Group 6
not inoculated
LS = Low speed centnfugation
HS = High speed centrifugation
UC = Ultra centrifugation
[0215] Groups 1, 2, 3 and 4 were housed in isolators. Groups 5 and 6 were housed in separate animal rooms on a stainless steel cage with wire floor (0.5 m 2 ) and a device to collect feces. Floors of isolators and cages was covered with paper to allow contact of the birds with fresh droppings. The chicks were ad libitum fed with a commercial broiler mash (CAVO-LATUCO ) and had free access to drinking water which was provided through cups. They were daily observed for clinical signs of MAS. On day 14 post infection, chicks from each group were individually weighed, killed and post-mortem examined. Intestines (including) pancreases were collected and stored at −70° C. Blood samples were taken from all chicks post mortem. Alkaline Phosphatase activity was determined in blood plasmas prepared from these blood samples.
[0000]
Day 0:
Inoculation of chicks.
Day 14:
Weighing all chicks
Post - mortem examination
Collecting intestines, pancreases and blood samples.
Methods
[0216] Chicks were daily observed for clinical signs of MAS. Abnormalities and mortality were recorded. Chicks were weighed, killed and post mortem examined on day 14.
[0217] The parameters used for diagnosing MAS were: growth retardation, yellowish mucous droppings, poor feathering, bone abnormalities and high plasma alkaline phosphatase activity.
[0218] Blood samples were taken individually in heparinised tubes after chicks on day 14 post infection were killed. Plasma was prepared and examined for color (pale or yellow). Alkaline phosphatase activity (expressed in Units per liter) was determined in these plasma samples.
[0219] Intestines and pancreases were collected from each group on day 21 post infection. Samples were stored at ≦−60° C.
[0220] A selection of homogenates will be examined for the presence of viruses by inoculation of Chicken Kidney Cells (CKC.
Results
[0221] Chicks of group 1 (inoculated with fraction 1; pellet) were very ill during the first days post infection and 1 chick died. They had the lowest body weight on day 14. At post-mortem, bone disorders were seen. Plasma ALP values were highest in these chicks.
[0222] Chicks of group 2 (Low molecular particles and molecules) had bone disorders, elevated ALP and low bodyweights.
[0223] All clinical signs of MAS (growth retardation, pale shanks, pale and swollen intestines yellowish mucous droppings, poor feathering, bone abnormalities and high plasma alkaline phosphatase activity) were observed in chicks of groups 3 (fraction 3; viruses), 4 (fraction 4; recombined intestinal homogenate) and 5 (intestinal homogenate). Growth retardation started from the first week of life.
[0224] Mean body weight at different ages and results of post mortem examination on day 14 are summarized in Table 6B.
[0000] TABLE 6B Mean body weight (grams), Plasma Alkaline Phosphatase activity (ALP) and results of post-mortem on day 14 Mean bodyweight Mean in grams ALP(U/I) Plasma color Results of Group day 14 post day 14 post day 14 post post-mortem (fraction) infection infection infection day 21 post infection 1 300 b 46940 dark yellow 2/5 Chicks with disorders of ribs and (fraction 1; bacteria) 5/5 chicks with moderate disorders of tibiae. 2 377 a 24578 Pale 4/5 Chicks with (fraction 2; proteins moderate bone disorders of tibiae. and small viruses) 3 364 ab 23142 Pale 5/5 Chicks with pale shanks and pale (fraction 3; viruses) swollen intestines; 5/5 Chicks with severe bone abnormalities of ribs and tibiae. 4 388 a 27324 Pale 6/6 Chicks with pale shanks and pale (fraction 4; recombined swollen intestines; 6/6 Chicks with intestinal homogenate) severe bone abnormalities of ribs and tibiae. 5 364 ab 26440 Pale 5/5 Chicks with pale shanks and pale (intestinal homogenate) swollen intestines; 5/5 Chicks with severe bone abnormalities of ribs and tibiae. 6 474 c 6494 dark yellow No abnormalities. (not infected controls) a,ab,c different annotations mean; significant different mean body weight (Student's t-test p < 0.05)
Blood plasmas from groups 2, 3, 4 and 5 were pale. Blood plasmas from groups 1 and 6 were dark (yellow). Plasma alkaline phosphatase activities of groups 1, 2, 3, 4 and 5 were substantial higher than plasma alkaline phosphatase activity of group 6 (non infected controls). Results of examination of plasma on color and mean alkaline phosphatase activities are also presented in Table 6B. The results of bacteriological examination of fractions are summarized in Table 6C.
[0000]
TABLE 6C
Results of bacteriological examination (presence of bacteria on blood
agar plate) of fractions used to infect chicks in Example 6.
Presence of bacteria on blood agar plate
Fraction
Place of application
Segment 1
segment 2.
Fraction 1
Overgrown
Overgrown
individual colonies
(pellet after LS and HS)
Fraction 2
1 colony *
no bact. grown
no bact. grown
(supernatant after UC)
Fraction 3
2 colonies **
no bact. grown
no bact. grown
(pellet after UC)
Fraction 4
Overgrown
Overgrown
individual colonies
(combination of pellet after LS,
UC and supernatant after UC)
Fraction 5
Overgrown
overgrown
connected and
(intestinal homogenate)
individual colonies
* possibly gram negative rod
** possibly gram positive coccus.
Results
[0225] The results of the current experiment exclude bacteria from being causative agents of MAS and indicate a viral etiology of the disease because:
MAS was reproduced with fraction 3. This fraction (Pellet after Ultra centrifugation) was free of bacteria and consisted of viruses. MAS was partially reproduced with fraction 2. Chicks of group 2 had low body weights, bone disorders, pale blood plasma and high plasma ALP values. They did not have swollen pale intestines. Fraction 2 (supernatant after UC) was also free of bacteria and was supposed to consist mainly of low molecular particles and molecules. MAS was partially reproduced with fraction 1. Chicks of group 1 (inoculated with fraction 1; pellet after LS and HS) were very ill during the first days post infection and 1 chick died. They had the lowest mean bodyweight on day 14, bone disorders at post-mortem and extremely high Plasma ALP values. They did not have swollen pale intestines, pale shanks and pale blood plasma. Fraction 1 (pellet after LS and HS) was supposed to consist mainly of tissue and bacteria, but the procedure for preparing this fraction does not exclude the presence of viruses in this fraction.
Although the results of the current experiment indicate viruses as causative agents for MAS, they do not exclude proteins, toxins or other molecules being involved that could have been present in fractions. The possible involvement of these small substances in MAS might be further investigated by submitting the fractions to PAGE.
EXAMPLE 7
[0229] Vaccines containing a combination of inactivated avian reovirus within the range of 10 4 -10 10 TCID 50 and inactivated avian adenovirus within the range of 10 4 -10 10 TCID 50 are prepared and administered to chicks. The vaccines show efficacy in protecting the animals from symptoms associated with MAS.
EXAMPLE 8
[0230] Vaccines containing a combination of live attenuated avian reovirus within the range of 10 2 -10 9 TCID 50 and live attenuated avian adenovirus within the range of 10 2 -10 9 TCID 50 are prepared and administered to chicks. The vaccines show efficacy in protecting the animals from symptoms associated with MAS.
[0231] While the invention has been described in several of its various embodiments, it is fully expected that modifications thereto may be undertaken by the skilled artisan without departing from the invention's overall true spirit and scope.
REFERENCES
[0000]
Kouwenhoven, B., Vertommen, M. and Van Eck, J. H. H. (1978).
Runting and leg weakness in broilers; involvement of infectious factors.
Veterinary Science communication, 2 : 253-259.
Vertommen, M., Van der Laan, A., Veenendaal-Hesselman, Henriëtte M. (1980 b).
Infectious stunting and leg weakness in broilers:
II. Studies on alkaline Phosphatase isoenzymes in blood plasma.
Avian Pathology, 9: 143-152.
Vertommen, M., Van Eck, J. H. H., Kouwenhoven, B. and Van Kol, N. (1980 a).
Infectious stunting and leg weakness in broilers:
I. Pathology and biochemical changes in blood plasma.
Avian Pathology, 9: 133-142.
McFerran, J. B. and McNulty, M. S.(1993)
Virus infection in birds page 520-535
Elsevier Science Publishers Amsterdam.
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The causative agent(s) of Avian Malabsorption Syndrome (MAS) are isolated and used to prepare vaccines for use in the prevention of diseases resultant therefrom. The vaccines contain at least two avian viruses—the reovirus and adenovirus—and optionally include another virus which inflicts poultry. The viruses may be live, attenuated live, or inactivated when incorporated into the vaccine. The vaccine itself may be administered in ovo, to new-born or growing chicks, or to adult fowl.
| 0
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method and apparatus for the stepwise forming of a series of troughs of varying depth and width into a metal strip with the aid of a number of sets of bottom (male) and top (female) dies sequentially applied to the metal strip to gradually form the troughs. At least the first of the sets of bottom and top dies serves to pre-form the metal strip which is, in additional forming steps, further impressed until the desired trough is embossed in the metal strip.
2. Description of the Prior Art
It is difficult to impress troughs into thin metal foil strips since they are very susceptible to cracking. German patents Nos. 1,162,316; 1,198,314 and 1,217,911 show how cracking of the metal foil can be avoided if the impressions are made carefully and sufficient foil material is available in the imprint area. In order to have sufficient foil material available it has, for example, been proposed to prepleat the strip in the area in which a trough is to be impressed.
German publication Dt-AS No. 1,602,485 proposes to imprint, during the initial impressing steps, a trough which is deeper than the final trough and to leave a gap between the bottom and top dies in their engaged positions. This, especially, facilitates the forming of decorative pleats in the bottom wall of the trough. As a result of the right-angled side walls of the troughs and a uniform cross-section the consumption of material is naturally constant over the full length of the trough. However, if the corss-section is not uniform over the length of a trough (i.e. the width of the metal strip) that is if the trough has no uniform depth or width the strip material consumption is different at the opposite sides of the strip and the strip tends to deviate from the rectilinear advancing movement through the successive forming stages which may result in faulty imprints.
SUMMARY OF THE DISCLOSURE
A new method and apparatus for forming a series of elongated troughs with different cross-sections at their opposite ends into a metal foil strip in such a manner that the strip travels rectilinearly through the apparatus consisting of several sets of lower and upper dies which, one after the other, engage the metal strip that is moved stepwise from stage to stage. In a first stage a pleat is formed across the strip which is then formed into a trough having essentially the same cross-section at both ends. In the final forming stages the size of the trough is then reduced by the formation of pleats in the side wall of the trough at one end thereof so as to obtain the final form of the trough. With this method the same amount of strip foil is consumed at both sides of the strip so that the strip moves rectilinearly through the apparatus without jamming.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more readily apparent from the following description of preferred embodiments thereof explained in connection with drawings in which:
FIG. 1 shows, in cross-section along lines I--I of FIG. 2, the bottom and top dies in opened positions with a metal strip therebetween;
FIG. 2 is a top plan view of the metal strip showing the various impressing steps;
FIG. 3 is a longitudinal cross-sectional view of the apparatus with its dies spaced apart and the metal strip disposed therebetween, the cross-section being taken along line III--III of FIG. 2;
FIG. 4 is a cross-sectional view of the apparatus along lines IV--IV of FIG. 1 with the dies being closed and showing the pre-forming stage;
FIG. 5 is a cross-sectional view along lines V--V of FIG. 1 showing the second forming stage with the dies in the closed position;
FIG. 6 is an enlarged sectional view of a portion of the second forming stage shown in FIG. 5;
FIG. 7 is a bottom view of the top die of FIG. 6;
FIG. 8 is a longitudinal cross-sectional view of an apparatus for forming, in parallel, more than one series of troughs and taken along line VIII--VIII of FIG. 9; and
FIG. 9 is a bottom view of the top die of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An apparatus for forming troughs as shown in FIG. 1 includes a bottom (male) die structure 20 having a projection 21, a pre-forming member 22 and two finishing forming portions 23 and a top die having a pre-forming die portion 6 and a finishing die portion 7. A thin metal strip 1 such as aluminum foil is disposed between the top and bottom dies and is advanced stepwise when the dies are spaced apart. After each advancing step the top and bottom dies are closed for stepwise forming of the troughs into the metal strip.
This is done by first forcing the finishing die portion 7 toward the finishing forming portions 23 by means of a drive shaft 25 to which the finishing die portion 7 is connected. This brings the troughs 2 of the strip 1 into their final form. At the same time, the front end surface 26 of the finishing die portion 7 forces the strip 1 in engagement with the exit end portion of the pre-forming member 22, with respect to the advancing direction (arrow A). Then, the pre-forming die portion 6 which is slidingly guided by the drive shaft 25 of the finishing die portion 7, is forced onto the pre-forming member 22 so as to generate a preliminary form 27 (FIG. 2). At the same time, the strip foil is pulled over the projection 21 thereby generating a pleat 28 extending across the width of the strip.
After these forming steps the die portions 6 and 7 are pulled back and the strip 1 is moved a step forward in the direction of arrow A. For the sake of clarity and simplicity, the drive means for the strip 1, and for the dies 6, 7, however, are not shown. They may be of any well known type.
As can be seen from FIG. 2, in the pre-forming stage (pre-forming member 22, pre-forming die portion 6, front end surface 26 of the finishing die portion 7), there is formed a preliminary trough 27 which, in length as well as in width, is somewhat larger than the final trough 2. In addition, the prelimary trough 27 includes auxiliary deformations 8 which use up some strip material in order to achieve an equal consumption of strip material over the length of the preliminary trough that is over the width of the strip in spite of the different cross-sections 5 and different depths 3 of the trough along the line 4 of greatest depth in the final forming stages of the trough 2. This can be seen especially well from the cross-sectional view (FIG. 3) taken along line III--III of FIG. 2 and from FIG. 4 wherein the faces 22a and 22b are about equal in size. In the finishing stage (finishing die portion 7 and finishing forming portion 23) some of the superfluous material of the auxiliary deformations 8 is pleated so that the actual surface area thereof is reduced and the foil is brought into the final form of trough 2. In the shown example, this applies to the conical end of the trough 2 and also to a constriction in the middle of the trough. As it can further be seen from FIGS. 1 and 2, the constriction in the middle of the trough 2 is already initiated in the pre-forming stage by the front end surface 26 of the finishing die portion 7. In order to make use of the available foil material and, at the same time, to keep the tension in the foil within certain limits so as to avoid rupturing of the foil material during the final forming stage, slots 16 are cut into the foil strip outside the preliminary trough 27 and transverse to the direction of tensions in the strip that is in the normally unused foil material between adjacent troughs. For cutting the slots 16 the pre-forming die portion 6 is provided with a cutting blade 15 and the bottom die 20 has an opening 29 for receiving the blade 15.
In some cases, the metal strips have imprints and then it is necessary to hold the imprinted strip area in a predetermined position in contact with the finishing forming portion 23 even in the area of the auxiliary deformations. For this purpose the strip is clamped between the upper and lower dies at certain points 10, for example an imprint such as letters, already before the beginning of the forming step. This can be done in a simple manner by providing the pre-forming and finishing die portions 6 and 7 with stud-like down holders 11 which are axially movably disposed in passages extending through the dies and springs 30 disposed in the passages 11 which springs force the down holders into engagement with the strip (foil) before the dies (FIGS. 4, 5).
In the finishing stage it is especially important that the edges 13 in areas of curvatures with small radii 14 are so designed that the formation of the pleats is initiated in the desired manner already when the upper die 7 approaches the lower die in order to avoid the formation of cracks. To achieve this, the edges 13 are rounded and have grooves 12 for the control of the formation of the pleats, the grooves extending about normal to the circumference 31 of the die cavity when viewed from the bottom (FIGS. 6 and 7).
With the method and arrangement according to the invention it is also possible to imprint several parallel rows of troughs into the strip at the same time. A respective arrangement for doing that is illustrated in FIGS. 8 and 9. The finishing die 17 has two parallel rows of cavities 32 whose conical ends are pointed toward each other. The pre-forming die 36 also has two cavities 33 which, with respect to the cavities 32 for the final trough, have extensions 34 in line with the conical ends of the cavities 32 which extensions serve as auxiliary cavities.
Corresponding to the cavities 32 and 33 there are pairs of forming members 35, 37, and 38. At their front ends facing the incoming strip 1 (in the direction of arrow A) the top dies 17, 36 have fingers 18, 39 which protrude in a direction opposed the feed direction of the strip and which engage the strip foil in the middle between the rows of troughs so as to initiate the forming of the troughs in the pre-forming stages between the pairs of pre-forming members 37, 38. This provides for the material needed for the auxiliary cavities. The troughs are subsequently formed in the rows. The initial pre-forming member 38 and the main pre-forming member 36 have openings 40, 41 for receiving the fingers 18, 39 when the bottom and top dies are in engagement with one another.
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Method and apparatus for forming a series of elongated troughs having different widths at their opposite ends into a metal foil strip in several forming stages with the aid of sets of upper and lower dies which, one after the other, engage the metal strip which is promoted stepwise from stage to stage. The troughs are formed in a pre-forming stage with the same width at both ends and in the final forming stages the width of the trough at one end is reduced by the formation of pleats so as to obtain the final form of the troughs without bending of the strip.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/315,655 under 35 U.S.C. §119(e), filed Aug. 29, 2001, entitled “DIGITAL BASEBAND PROCESSOR,” by Allen, et al. The entirety of the above provisional application is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to programmable serial ports and more particularly, to high-speed programmable serial ports.
BACKGROUND OF THE INVENTION
[0003] Many serial port arrangements are known in the field of electronic circuits and data communications. For example, arrangements include static serial ports for transmitting and receiving data of a selected serial communications protocol (e.g., Universal Asynchronous Receiver Transmitter (UART) devices), and configurable serial ports (e.g., microprocessors with software controlled serial ports). Configurable serial ports provide the possibility of servicing a multiplicity of protocols with a single serial port device. Static and configurable serial ports are used for a wide range of applications, including communication with display devices, communication with modems, and serving as a universal system connector (USC).
[0004] Numerous serial communications protocols (also referred to herein as protocols) have been promulgated (e.g., to name a few, UART, I 2 C, HC11, IrDa), each defining specific parameters under which serial bits of data are communicated between serial ports. The parameters defining a protocol may include factors such as the timing of bits received or transmitted, electrical parameters (e.g., signal polarity, line driver characteristics, such as open-source or open collector output impedances, etc.), and logical definitions of bit meanings and sequences and sequences.
[0005] One example of a configurable serial port is provided by the Motorola M68HC11 family of microcontrollers, which include a programmable serial port known in the art as the Motorola Synchronous Serial Peripheral Interface (SPI). Such serial interfaces may be disadvantageous for several reasons. For example, the processor must execute a software program to control the serial port, and all data bits to be sent over signal paths pass through the processor, thus loading the processor, beyond whatever load is imposed on the processor as the processor performs the tasks for which it is otherwise employed. Also, because the serial hardware is a power-consuming part of the processor, additional power is consumed whenever the processor is executing a software program even if the serial port is inactive.
[0006] As an alternative to microcontroller-controlled programmable serial ports, programmable serial ports implementing a finite state machine have been developed to off-load from the processor the burden of having to control many aspects of the serial port. An example of such a programmable serial port is given in U. S. patent application entitled GENERIC SERIAL PORT ARCHITECTURE AND SYSTEM, Ser. No. 09/706,450, by Sorenson, filed Nov. 3, 2000.
[0007] [0007]FIG. 1 is a block diagram of such a programmable serial port 100 . In FIG. 1, when operating in transmit mode, a shift register 110 receives a parallel set of data bits on channels 102 from a buffer 120 and outputs the bits as a serial output on channel 104 (via a driver 180 ) under the control of a finite state machine (FSM) 120 . Conversely, when operating in a receive mode, shift register 110 receives a serial input on channel 104 and outputs a parallel set of data bits on channels 102 .
[0008] The phrase “finite state machine” is defined herein to be any device that stores an existing status (e.g., a program counter and a plurality of other registers) and upon receiving an input (e.g., an instruction or command), changes to a new status and/or causes a deterministic action or output to take place in response to the existing status and the input. While FSMs may not include an arithmetic logic unit (ALU) or other circuits conventionally associated with microprocessors, the term FSM as defined herein does not exclude devices including such circuitry or elements.
[0009] In programmable serial port 100 , instructions corresponding to rules for implementing two or more protocols are stored in a memory 130 . Using the instructions from memory 130 , FSM 120 executes instructions corresponding to a protocol selected by controller 150 to provide an output according to the specified protocol on channel 104 . A bit counter 170 provides the FSM 120 with a numbered count of bits transferred, to facilitate providing an output according to the selected protocol, as the processing of a bit frequently depends on the position in either the parallel channels 102 or the received or transmitted serial bit stream on channel 102 . Typically an output is directed through a driver 180 to provide an output having (or compatible with) specific electrical parameters. In conventional FSM-based programmable serial ports (e.g., programmable serial port 100 ), execution of instructions to provide an output according to a selected protocol requires that FSM 120 receive a clock pulse from clock generator 160 and provide a clock signal to shift register 110 to control output of each bit from shift register 110 to channel 104 or buffer 120 , as the case may be, and requires that the FSM maintain and process a bit count provided by a bit counter 170 .
[0010] Providing an output according to a selected protocol requires that an output be provided at specified times. For example, in some protocols, an output on channel 104 must occur within a specified time period following receipt of a timing signal (e.g., a rising edge on a channel 190 ) by serial programmable serial port 100 . Because the time interval between receiving the clock signal and providing the output may be very short, an instruction set to achieve an output must be capable of short execution times or the serial port may have inadequate data output speed, and in some instances may be prohibited from servicing some output protocols.
[0011] [0011]FIG. 2 is a flow chart 200 of a typical set of instructions for a conventional programmable serial port to achieve a standard output (e.g., a UART-compatible output). At step 205 , the FSM waits for an indication that the shift register is full of data (i.e., a parallel set of data). At step 210 , the FSM loads the driver with a start state (e.g., logic value one or zero). At step 220 , the FSM initializes the bit counter (e.g. an initial bit count is loaded). At step 240 , the FSM identifies the lines of code that define the loop by which data is shifted from the shift register. The first data bit is sent and maintained for as many clock cycles as necessary for the protocol, and the bit counter is decremented by the FSM at steps 250 and 260 , respectively. Subsequent data bits are sent and the bit counter is decremented by the FSM (step 270 ), until the bit counter reaches zero. After all data bits are sent, the FSM causes a parity bit to be sent at step 280 . Finally, the driver is set to a stop state at step 290 .
[0012] One method of achieving faster execution time is to increase the clock rate at which the FSM executes instructions such that a greater number of instructions are executed in a given time interval (e.g., the time interval between a tining signal and commencement of outputting of serial data bits); however, a faster clock rate may require faster and more expensive electronic components. Additionally, a faster clock rate may require an increased power expenditure. Accordingly, a programmable serial port is needed which is able to receive and process any necessary inputs (e.g., timing signals) and provide any necessary outputs at a relatively high speed, while maintaining a relatively low clock speed. Additionally, a programmable serial port is needed which is capable of providing outputs and accepting inputs according to a wide variety of protocols.
SUMMARY OF THE INVENTION
[0013] Aspects of the present inventions are directed to programmable serial ports having an FSM, a clock generator controllable by the FSM to produce programmed clock signals pursuant to an FSM instruction, a shift register module capable of producing an output of data bits pursuant to the programmed clock signals and any FSM bit operations, and maintaining a numbered count of output data bits; accordingly, the number of instructions executed by the FSM to achieve an output according to a selected protocol is relatively fewer and the overall execution time to achieve an output is relatively short, since the clock generator may be controlled at a relatively high level by the FSM.
[0014] A first aspect of the invention is a clock generator for use in a programmable serial port having a first shift register module and a finite state machine, comprising a first output channel to a first shift register module, the first output channel providing to the first shift register a first clock signal comprising a predetermined number of pulses, at a predetermined rate in response to at least one instruction determining said number of pulses and said rate, and an input channel to receive at least one instruction, the at least one instruction indicative of the predetermined number of pulses, and the predetermined rate.
[0015] The clock generator may further comprise a second output channel to a second shift register module, the second output channel providing a second clock signal comprising a predetermined number of pulses, at a predetermined rate in response to at least one instruction. Optionally, the clock generator may further comprise a second output channel to a finite state machine, the second output channel providing a second clock signal to the finite state machine. In some embodiments, the clock generator further comprises a gate coupled to the second output channel, such that the second clock signal passes through the gate, the gate controllable by the at least one of the instructions indicative of the predetermined number of the predetermined number of pulse, and the predetermined rate. In other embodiments of the first aspect of the invention, the clock generator further comprises a divider coupled to the second output channel to receive the second clock signal, and coupled to the first output channel to provide the first clock signal, whereby the second clock signal is divided to form the first clock signal.
[0016] A second aspect of the invention is a shift register control module, to control a first shift register module including a first shift register having an input channel to receive a parallel input of a first plurality of bits and a serial output channel to provide a serial output of a second plurality of bits, and further having at least one register for controlling the shift register responsive to instructions, comprising a first finite state machine to provide said instructions, and a clock generator coupled to the first finite state machine, providing a first clock signal comprising a first plurality of clock pulses to the first shift register in response to at least one instruction from the first finite state machine, the serial output of the second plurality of bits occurring in response to at least one of said instructions provided to the first shift register module and the first clock signal.
[0017] The first finite state machine may be clocked by a second signal provided by the clock generator. In some embodiments, the clock generator is coupled to the first finite state machine through a gate controllable by an at least one of the instructions. Optionally, the shift register control module, may further comprise a divider coupled to the first finite state machine to receive the second clock signal, and coupled to the first shift register module to provide the first clock signal, wherein the second clock signal is divided to form the first clock signal. In some embodiments of the second aspect of the invention, the shift register control module the at least one program instruction is from the finite state machine, and in some embodiments the finite state machine is configured and arranged to provide instructions corresponding to a plurality of serial communications protocols.
[0018] A third aspect of the invention is a programmable serial port, comprising a first shift register module including a shift register having an input channel to receive a parallel input of a first plurality of bits and a first output channel to provide a serial output of a second plurality of bits, and further having a register for controlling the shift register module responsive to instructions, a first finite state machine to provide said instructions, the finite state machine providing said instructions to the shift register module to control operation of the shift register, and a clock generator coupled to the finite state machine, providing a first clock signal comprising a first plurality of clock pulses to the first shift register module in response to at least one of said instructions from the finite state machine, the serial output of the second plurality of bits occurring in response to said instructions provided to the shift register module and the first clock signal.
[0019] Optionally, the clock generator comprises a second output channel to the first finite state machine, the channel providing a second clock signal to the first finite state machine, the signal comprising a second plurality of clock pulses. In some embodiments, the clock generator is coupled to the first finite state machine through a gate controllable by an at least one of the instructions. The gate may be controllable to block the second clock signal while shift register provides the serial output.
[0020] In some embodiments, the programmable serial port further comprises a divider coupled to the second output channel to receive the second clock signal, and coupled to the first output channel to provide the first clock signal, wherein the second clock signal is divided to form the first clock signal. The finite state machine may be configured and arranged to provide instructions corresponding to a plurality of serial communications protocols. Each of the second plurality of bits may be output in response to a clock pulse of the second plurality of pulses.
[0021] In some embodiments, the shift register module further comprises a bit counter, the bit counter configured to maintain a numbered count of the serial output of the second plurality of bits. Optionally, the bit counter is decremented in response to a clock pulse of the second plurality of pulses. Each of the second plurality of bits may be one of a data bit, a parity bit, and a stop bit. Optionally, each of the second plurality of bits is selected based on the bit count.
[0022] The shift register module may further comprise a parity generator. In some embodiments, the shift register module outputs a parity bit from the parity generator in response to a clock pulse of the second plurality of pulses. The programmable serial port may further comprise a programmable driver coupled to the first output channel to control the electrical parameters of the serial output. An interrupt processing module may be coupled to the first finite state machine to cause an interrupt of the finite state machine. The programmable serial port may further comprise a second shift register module, the clock generator coupled the second shift register module to provide a second clock signal comprising a second plurality of clock pulses, the second shift register module providing a second serial output in response to the second clock signal.
[0023] A fourth aspect of the invention is a programmable serial port, comprising a shift register module having an input channel to receive a parallel input of a plurality of bits and an output channel to provide a serial output of the plurality of bits, the shift register module including a shift register to provide the serial output and a bit counter, the bit counter configured to maintain a numbered count of the serial output of the plurality of bits, the serial output and the bit counter responsive to instructions and a finite state machine coupled to the shift register module to provide said instructions to the shift register module.
[0024] The bit counter may be decremented in response to a clock pulse. In some embodiments, the shift register module further comprises a parity generator. The shift register module may provide a parity bit in response to the numbered count. Each of the plurality of bits corresponding to the serial output may be one of a data bit, a parity bit, and a stop bit. Optionally, each of the plurality of bits corresponding to the serial output is selected based on the numbered count.
[0025] A fifth aspect of the invention is a method of controlling a shift register module comprising a first shift register containing a first plurality of bits, to provide a serial output according to a selected one of a plurality of serial communications protocols, the first shift register module coupled to a clock generator and a finite state machine, said method comprising according to the selected protocol, selecting an instruction sequence to be executed by the finite state machine from among a plurality of instruction sequences, each of the instruction sequences corresponding to a protocol, controlling the clock generator according to an instruction of the selected instruction sequence to provide a first plurality of clock pulses to the shift register module, without further control by the finite state machine; and outputting a second plurality of bits corresponding to first plurality of bits in response to the clock pulses and execution of the instruction sequence.
[0026] The method of controlling a shift register module may further comprise an act of maintaining a count of the second plurality of bits. The method of controlling a shift register module may further comprise an act of selectively outputting a parity bit in response to the count. Some embodiments of the method of controlling a shift register module further comprise the act of controlling the clock generator to provide a third plurality of clock pulses to a second shift register module containing a third plurality of bits, and outputting a fourth plurality of bits corresponding to third plurality of bits, in response to the clock pulses.
[0027] Optionally, the method of controlling a shift register, may further comprising an act of controlling the clock generator to provide a second plurality of clock pulses to control execution of the instruction sequence by the state machine. In some embodiments, the method of controlling a shift register, further comprises an act of blocking the second plurality of clock pulses, wherein the executing of the plurality of instruction is caused to cease, while outputting the second plurality of bits. The controlling of the clock generator according to an instruction may include specifying the number of pulses and the clock rate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Illustrative, non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which the same reference number is used to designate the same components in different figures, and in which:
[0029] [0029]FIG. 1 is a block diagram of a conventional programmable serial port;
[0030] [0030]FIG. 2 is a flow chart of a typical set of instructions for a conventional programmable serial port to achieve a standard output (e.g., a UART-compatible output);
[0031] [0031]FIG. 3A is a functional block diagram of a first exemplary embodiment of a programmable serial port according to at least some aspects of the present invention;
[0032] [0032]FIG. 3B illustrates a timing diagram for an exemplary output bit stream from a shift register module configured to automatically output a parity bit and a stop bit;
[0033] [0033]FIG. 4A is a functional block diagram of a second exemplary embodiment of a programmable serial port according to at least some aspects of the present invention;
[0034] [0034]FIG. 4B, a schematic diagram of an exemplary interrupt processing module;
[0035] [0035]FIG. 5 is a schematic diagram of an exemplary embodiment of a transfer register shift module according to at least some aspects of the present invention;
[0036] [0036]FIG. 6 is a schematic diagram of an example of a driver (e.g., driver in FIG. 3A) as may be used in a programmable port;
[0037] [0037]FIG. 7 is a schematic diagram of one example of an embodiment of a clock generator for use with at least some programmable serial ports according to aspects of the present invention;
[0038] [0038]FIG. 8A illustrates an exemplary clock generator output for a clock generator generating one clock pulse in a standard mode;
[0039] [0039]FIG. 8B illustrates a clock generator output for a clock generator operating in a power-save mode;
[0040] [0040]FIG. 9 is a flow chart of an exemplary sequence of instructions for a programmable serial port according to some aspects of the present invention, to achieve a standard output (e.g., a UART compatible output);
[0041] [0041]FIG. 10A is a schematic illustration of one suitable memory organization suitable for use with present invention;
[0042] [0042]FIG. 10B is a schematic illustration of an exemplary FSM decode architecture suitable for use with the memory organization of FIG. 10A; and
[0043] [0043]FIGS. 11A and 11B are tables illustrating one exemplary set of binary implementations of an instruction set.
DETAILED DESCRIPTION
[0044] [0044]FIG. 3A is a functional block diagram of a first exemplary embodiment of a programmable serial port 300 according to at least some aspects of the present invention. Programmable serial port 300 transfers a parallel set of data bits comprised of a plurality of bits (e.g., a byte of data) on channels 302 , and provides a serial output of a second plurality of bits corresponding to the first plurality of bits on a channel 304 . Programmable serial port 300 also may be used to receive a serial input on channel 304 and provide a parallel output on channels 302 . Furthermore, programmable serial port 300 may operate in simplex or half duplex modes. In the discussion which follows, emphasis will be placed primarily on the parallel input/serial output mode of operation, as the serial input/parallel output operation usually will be apparent therefrom without further elaboration.
[0045] Programmable serial port 300 includes of a finite state machine 320 , a clock generator 360 (also referred to herein as a clock pulse generator), a shift register module 312 , and a driver 380 . A controller 350 (of a conventional nature) controls some functions of the programmable serial port 300 , for example, by initializing any of the above components comprising programmable serial port 300 , by selecting a protocol under which the serial communication is to occur, and filling buffer 320 .
[0046] As described in greater detail below, FSM 320 controls operation of shift register 312 and clock generator 360 by providing commands to each of them, including controlling configuration registers of each. FSM 320 executes instructions corresponding to a protocol program selected by controller 350 . For example, the controller provides a program code line number of a set of instructions corresponding to a selected protocol program stored in a memory 330 . The memory may include a plurality of instructions each corresponding to a different protocol
[0047] A shift register module 312 receives a parallel input of a plurality of bits from a buffer 320 on channels 302 , and provides a serial output corresponding to the plurality of bits to driver 380 . Shift register module 312 includes a shift register 310 to serialize data received on channel 302 , and a bit counter 370 . Bit counter 370 is configured to maintain a numbered count of the bits of serial data output by shift register module 312 .
[0048] Clock generator 360 is coupled to finite state machine 320 , and provides one or more clock pulses to shift register 310 in response to at least one instruction from finite state machine 320 . The clock pulses control timing of the shifting of data into and out of shift register module 312 . Clock generator 360 has an input channel to receive at least one instruction from the finite state machine 320 , and an output channel to provide clock pulses to the finite state machine 320 . For example, in response to at least one instruction, clock generator 360 may provide to shift register 310 a predetermined number of clock pulses, at a predetermined rate, at a predetermined time (or after a predetermined delay). In some embodiments, finite state machine 320 provides a single command to clock generator 360 to generate a predetermined number of pulses, at a predetermined rate, to reduce the amount of execution time necessary to control the clock generator. Therefore, the number of instructions executed by the FSM to achieve an output according to a selected protocol is relatively fewer and the overall execution time to achieve an output is relatively short; thus, the programmable serial port 300 is capable of providing outputs and accepting inputs according to a wide variety of protocols. FSM 320 and clock generator 360 together form a shift register control module 355 for controlling shift register module 312 .
[0049] In response to a clock pulse received from clock generator 360 (which may be preceded by other clock pulses for other purposes), shift register module 312 outputs a single data bit to driver 380 , and the bit counter 370 is decremented or incremented (depending on whether a protocol specifies that the most significant bit or the least significant bit is to be transmitted first). Shift register 312 may be configured such that, for selected protocols, the first clock pulse received after the counter reaches zero automatically results in an output of a parity bit, and the second clock pulse received after the counter reaches zero results in output of a stop bit.
[0050] [0050]FIG. 3B illustrates a timing diagram for an exemplary output bit stream 390 from a shift register module 312 configured to automatically output a parity bit and a stop bit. In addition to output bit stream 390 , a corresponding bit count 392 of bit counter 370 (shown in FIG. 3A above), and clock signal 394 from clock generator 360 (shown in FIG. 3A) are illustrated. In the exemplary bit stream 390 , the data bits are assumed to be output on the rising edge of clock signal 394 . Upon receiving each of the rising edges 396 a - d (corresponding to bit counts 1 - 4 ), respectively, a corresponding data bit is output. Upon receiving the first rising edge 396 e when the bit count is 0, a parity bit is output; and upon receiving the second rising edge 396 f when the bit count is zero, a stop bit is output.
[0051] Referring again to FIG. 3A, driver 380 is coupled to channel 304 to provide line driving and receiving circuitry and parameters required by the selected protocol. For example, driver 380 may allow for selection of desired line driver circuit type such as an open source or open collector line driver circuit, selection of the polarity of an output signal, and selection of a high impedance state. Additionally driver 380 may allow for selection of a data source (e.g., output at a fixed logic value (i.e., one or zero), an input/output from an FSM, or an input/output from a shift register). The driver may also detect data-in/data-out mismatches. Additionally, in half duplex mode, driver 380 may multiplex data sent and received on channel 304 . Driver 380 preferably is programmable in response to a protocol selection signal shown as supplied on line 381 to effect protocol-related selections and operations. The protocol selection signal comes directly or indirectly from controller 350 . While driver 380 is illustrated as having output channel 304 , it is understood that driver 380 may provide one or more additional outputs, such as a clock signal(s). Driver 380 is further described, below, with reference to FIG. 6.
[0052] [0052]FIG. 4A is a functional block diagram of a second exemplary embodiment of a programmable serial port 400 according to at least some aspects of the present invention. Programmable serial port 400 includes driver 480 , two finite state machines 420 and 421 , each having a corresponding memory 430 and 431 , shift register module 412 and 413 , and clock generator 460 and 461 . Shift registers modules 412 and 413 , have corresponding shift registers 410 and 411 and bit counter 470 and 471 . Shift registers 410 and 411 receive parallel data bits from buffers 422 and 423 and provide a serial output on channels 404 and 405 , respectively.
[0053] As above, a controller 450 controls some functions of the programmable serial port 400 , for example, by initializing any of the above components comprising programmable serial port 400 and by selecting a protocol under which the inputs and outputs are processed.
[0054] Programmable serial port 400 is configured to allow simultaneous transmitting and receiving of data via shift register modules 412 and 413 , respectively; accordingly, programmable serial port 400 is capable of full-duplex communication or half duplex communication. To achieve full duplex communication, shift registers modules 412 and 413 operate simultaneously to send and receive data, respectively; and to operate in half duplex mode, shift register modules 412 and 413 transmit/receive data on alternate time cycles.
[0055] In some embodiments, programmable serial port 400 includes two event counters 480 and 481 associated with FSMs 420 and 421 , respectively. Event counters 480 and 481 are registers which increment or decrement in response to an input, such as a clock signal or a signal from FSMs 420 and 421 . Each of event counters 480 and 481 is capable of providing a corresponding count register value. Counters 480 and 481 are configurable to increment or decrement in response to an input from an FSM or other source (e.g., a clock) For example, a count register value may be accessible via the Compare instruction (discussed below), additionally a count register may be hardwired to provide an output to an associated FSM upon the occurrence of an event (e.g., the counter 480 , 481 is decremented to zero, or a register overflow has occurred.) In some embodiments, upon the execution of specified instructions (a Delay instruction, a Wait command or a Clock command invoking the power save mode (each such instruction being described below)) an FSM clock signal 705 and 706 (visible in FIG. 7) is gated by a gate 708 , 709 until the FSM receives an output from event counter 480 , 481 indicating that the counter 480 , 481 has decremented to zero.
[0056] In some embodiments, programmable serial port 400 may include a status register 495 and a comparator 490 . Status register 495 is capable of receiving data indicative of the status of any other component of programmable serial port 400 (e.g., a bit may indicate that a particular register is full, empty or overflowed, or may indicate a parity bit error). FSMs 420 and 421 may perform conditional operations, for example, based on any of the bits of the status register or an event counter 480 , 481 count value. A comparator 490 may be included to facilitate the execution of conditional operations by FSMs 420 and 421 . For example, comparator 490 may compare a data value in a selected register.
[0057] Optionally, interrupt processing may be provided by interrupt processing modules 455 and 456 . Referring to FIG. 4B, a schematic diagram of an exemplary interrupt processing module 455 is illustrated. An interrupt processing module is defined configured and arranged to selectively interrupt an FSM according to at least a first operand. Interrupt processing module includes a first interrupt select register 457 to control multiplexers 462 and 463 , which provide a first operand and a second operand, respectively, to an operator module 464 . For example, first operand and second operand can be selected bits of status register 495 or one of first operand, and second operand may be a selected data value. Operator module 464 performs a selected operation on the selected operands and generates an output (e.g., logical and or logical or of their values). An interrupt configuration register 466 may be used to control enabling of an interrupt, inversion of an input or an output, and whether the comparison is performed upon receiving a detected level or edge. An interrupt configuration register may contain an interrupt enable bit to control an AND gate 469 , to determine whether an interrupt should be provided to an FSM and thereby cause an interrupt of the FSM.
[0058] Upon receiving an interrupt, an FSM enters a routine beginning at an address (i.e., an interrupt vector) specified in interrupt address register 467 . Optionally, upon receipt of an interrupt, an FSM may store a return address in return register 468 to allow the FSM to return to the program line which the finite state machine was executing when the interrupt occurred.
[0059] [0059]FIG. 5 is a schematic diagram of an exemplary embodiment of a transfer register shift module 500 according to at least some aspects of the present invention. Shift register module 500 is defined herein to include at least a shift register 510 to serialize data received on channel 502 . Optionally, shift register 500 includes a bit counter module 570 , transfer logic 520 , and a transfer configuration register 506 . Bit counter 572 is configured to maintain a numbered count of the bits of serial data output by shift register module 500 .
[0060] Shift register module 500 receives an input comprising a set of parallel data bits from a buffer (e.g., buffer 420 in FIG. 2 4 ) on channel 502 or from an alternative source such as a memory location designated by FSM 420 (shown in FIG. 4) on channel 505 . The source of the parallel input is determined by a multiplexer 504 . Shift register module 500 provides a serial output corresponding to the parallel set of bits on channels 503 . For example, the output is provided to driver 380 (visible in FIG. 3A).
[0061] Shift register 510 serializes the selected parallel input. It is to be understood that shift register 510 as defined herein includes a conventional shift register or any other structure suitable for serializing data (e.g., a buffer coupled to multiplexer to a selectively output serial bits corresponding to a parallel set of input data bits).
[0062] Transfer logic 520 includes a multiplexer 522 to generate a stop bit and a multiplexer 523 to provide the stop bit as output. Additionally, transfer logic 520 includes a parity generator 524 and a multiplexer 525 to provide the parity bit to be output. Multiplexer 522 selects a logic level high or a logic level low as determined by a control signal specified by transfer configuration register 506 . A data bit multiplexer 526 allows shift register module 500 to control the source of the data output via channel 503 ; for example in a given protocol a given bit may be specified to come from the shift register 510 , FSM 420 , or may be selected to be logic level high or logic level low. Parity bit generator 524 receives data bit values output from data bit multiplexer 526 and calculates a parity bit.
[0063] As described above, according to aspects of the present invention, shift register module 500 is decremented automatically in response to receiving a clock pulse 572 . A parity bit is automatically output after transmission of data bits is competed (if a protocol requires), and a stop state is automatically entered after receipt of a predetermined number of clock cycles after the bit counter reaches zero, without need for the FSM to execute further instructions. Therefore, the number of instructions executed by the FSM to achieve an output according to a selected protocol is relatively fewer and the overall execution time to achieve an output is relatively short; thus, a programmable serial port is capable of providing outputs and accepting inputs according to a wide variety of protocols.
[0064] To achieve the above automatic outputs, bit counter module 570 has a bit counter 574 a comparator 572 , a count analyzer 576 , a path controller 578 , and other logic as described below. Path controller 578 receives a count value and controls shift register 510 , and transfer logic 520 to automatically provide output on channel 503 according to a selected protocol. Configuration register 506 contains data provided by controller 450 (shown in FIG. 4 above) to arrange and control each of the above components in accordance with the selected protocol.
[0065] An initial count value is provided to bit counter 574 by multiplexer 580 , depending on whether an input 506 a from configuration register 506 indicates that the selected protocol requires that the most significant bit or the least significant bit be sent first. If the most significant bit is to be sent first, multiplexer 580 provides an initial count value equal to the data size (i.e., the total number of data bits in a given set of data bits provided by channel 502 ) and bit counter 574 decrements to zero; and if the least significant bit is to be sent first, multiplexer 580 provides an initial count value equal to zero and bit counter 574 increments to a value equal to the data size. For each clock pulse, path controller 578 selects whether a data value, parity bit or stop bit is sent, based on the count from bit counter 574 .
[0066] Upon receiving a clock pulse 572 , bit counter 574 increments or decrements its count, based on the selected protocol. Path controller 578 receives the count value from bit counter 574 . Path controller 578 compares the count value to input 06 a from configuration register 506 to determine whether multiplexers 523 , 526 , 525 should be configured to provide a data bit from shift register 510 , a parity bit or stop bit on output channel 503 . Upon receiving a first zero count value, path controller 578 controls multiplexers 523 , 526 , 525 to output a least significant data bit, a parity bit or a stop bit. Upon receiving a second zero count, path controller 528 controls multiplexers 523 , 526 , 525 to provide a parity bit if input 506 a indicates that a parity bit is to be sent; and upon receiving a second zero count, path controller 578 controls multiplexers 523 , 526 , 525 to provide a stop bit if input 506 a indicates that a stop bit is to be sent. Path controller 578 may provide the count value to shift register 510 , which may be used as a pointer to the data bit to be output; accordingly, each of the data bits in shift register is output in response to a clock pulse.
[0067] Comparator 572 determines if the number of bits sent corresponds to the data size (e.g., if the least significant bit was transmitted first, comparator 572 determines if the counter value is equal to the data size). The output from comparator 572 is provided to count analyzer 576 , and the count analyzer 572 uses the input 506 a in combination with the output of the comparator to determine the next value of bit counter 574 . Until comparator 572 indicates that a number of bits corresponding to the data size has been sent, the bit count is incremented (or decremented), as appropriate. Upon receiving an output from comparator 572 indicating that a number of bits corresponding to the data size has been sent, count analyzer 576 determines whether a parity bit is necessary (e.g., after the counter reaches zero, the counter is allowed to remain at zero for a first pulse), or indicates that a stop bit is necessary (e.g., the counter is allowed to remain at zero for a second pulse after reaching zero), and whether circular mode is set (i.e., the counter is reset to the initial value after the parity bit and stop bit are set).
[0068] [0068]FIG. 6 is a schematic diagram of an example of a driver 480 as may be used in the programmable port. In the illustrated exemplary embodiment, six input/output driver circuits are provided: transfer data driver circuit 601 , transfer clock driver circuit 602 , receive data driver circuit 603 , receive clock driver circuit 604 , and two configurable input/output circuits 605 and 606 . For example, the configurable input/output circuits 605 and 606 may provide enable signals, one each for the receive and transmit ports, or may be used to receive a signal to be used as a slave clocking signal (described below).
[0069] The circuits may be any conventional input/output driver circuits. For example, the circuits may allow for selection of a source/receiver (e.g., power supply at logic one or zero, a input/output from an FSM, or an output from a shift register), selection of polarity of an output signal, selection of a high impedance state, detection of a data-in/data-out mismatch and parity bit computation. Optionally, a switch 610 may be included to allow mapping of input/outputs to any of six output pins 621 - 626 of an integrated circuit in which the programmable data port may be located.
[0070] [0070]FIG. 7 is a schematic diagram of one example of an embodiment of a clock generator 700 for use with at least some programmable serial ports according to aspects of the present invention. Clock generator 700 selects a master clock signal from a plurality of clock sources; for example, a master clock signal may be selected from a system clock 702 input from a microcontroller (e.g., microcontroller 450 in FIG. 4) or an auxiliary clock 703 input from any source of pulses suitable for use as a master clock signal 704 , and provides output clock signals. Such output clock signals include output clock signals 705 and 706 to a first and a second FSM (e.g., FSMs 420 and 421 in FIG. 4 above), output clock signals 726 and 736 to first and second shift register modules (e.g., shift register modules 412 and 413 ), and output clock signals 727 and 737 to a driver (e.g., driver 480 in FIG. 4).
[0071] An FSM clock generator module 710 receives master clock signal 704 and provides clock signal outputs 705 and 706 to the state machines (e.g., FSMs 420 and 421 in FIG. 4 above) on output channel 705 and 706 , respectively, to control instruction execution by the state machines. The output clock signals 705 and 706 may be divided or phase-delayed relative to master clock signal 704 by an FSM divider 712 coupled to output channel 705 and 706 , or FSM divider 712 may be bypassed (depending on the control signal applied to multiplexer 714 ) such that the clock signal outputs 705 and 706 are the same as master clock signals 704 . Gates 708 and 709 may be coupled to output channels 707 , 708 , respectively, to gate output clock signals 705 and 706 ; for example, gates 708 and 709 may be controlled (i.e., gated) by control signals from FSMs 420 , 421 , respectively, resulting from the execution of a Wait instruction, a Delay instruction or a Clock instruction invoking power-save mode, discussed below, and indicated generically by the inputs 708 a and 709 a labeled “control.”
[0072] FSM clock generator module 710 includes a configuration register 707 to determine the clock source of the master clock 704 , the division factor to be applied by divider 712 , and the phase of the output clock signals 705 and 706 relative to the clock source. The control inputs 708 a and 709 a also may be set by the contents of configuration registers in some embodiments.
[0073] A transfer clock generator module 720 receives a signal output 705 a from FSM clock generator module 710 , and alternative clock inputs (for example, an asynchronous slave clock signal 721 , a logical high, and a logical low signal) and provides clock signal outputs 726 and 727 (comprising a plurality of clock pulses) to a transfer shift register ( 412 in FIG. 4) and a driver (e.g., driver 480 in FIG. 4), respectively. Transfer divider 722 and transfer divider 724 divide the ungated output 705 a of FSM clock generator module 710 , and is coupled to the transfer shift register to provide clock signal output 726 . Multiplexer 725 selects among slave clock signal 721 , a logic level high and a logic level low; and multiplexer 745 selects between the output of multiplexer 725 and the output of transfer divider 722 , to provide clock signal output 726 . Multiplexer 723 selects between the output of transfer divider 724 and the output of multiplexer 745 to provide clock signal output 727 . Accordingly, by appropriate configuration of multiplexer 723 , the transfer shift register and transfer driver may be driven by the same clock signal.
[0074] Transfer clock configuration register 728 controls the divide factors of dividers 722 and 724 , and the start polarity, stop polarity of the outputs, whether the clock is operated in power-save mode (i.e., whether the FSM clock generator is turned off during transfer clock operation), and whether the operation of the FSM clock is started at the end of operation or one clock cycle early (for reasons discussed in greater detail below with reference to FIGS. 8A and 8B). Transfer clock divider register 729 controls the duty cycle of the transfer clock signal. For example, the transfer clock divide register may include a high-level divide ratio and a low-level divide ratio to determine the number of cycle in which clock signals 726 and 727 are in the high level and low level, thus determining the duty cycle. One of ordinary skill in the art would understand the implementation of such high-level and low-level divide ratios; therefore further details are not included herein.
[0075] A receive clock generator module 730 receives a signal output 705 a from FSM clock generator module 710 , and alternative clock inputs (for example, an asynchronous slave clock signal 731 , a logical high, and a logical low signal) and provides clock signal outputs 736 (and 737 to a receive shift register ( 413 in FIG. 4) and a driver (e.g., driver 480 in FIG. 4), respectively. Receive divider 732 and receive divider 734 divide the ungated output 705 a of FSM clock generator module 710 . Multiplexer 735 selects among slave clock signal 731 , and a logic level high and a logic level low, and multiplexer 746 selects between the output of multiplexer 735 and the output of transfer divider 732 to provide clock signal output 736 . Multiplexer 733 selects between output of transfer divider 734 and the output of multiplexer 746 to provide clock signal output 737 . Accordingly, by appropriate configuration of multiplexer 433 , the transfer shift register and transfer driver may be driven by the same clock signal.
[0076] Receive clock configuration register 738 controls the divide factor of dividers 732 and 734 , and the start polarity as well as the stop polarity of the outputs. Receive clock divider register 737 controls the duty cycle of the transfer clock signal. For example, receive clock divider register 737 may include a high-level divide ratio and a low-level divide ratio to determine the number of cycle in which clock signals 736 and 737 are in the high level and low level, thus determining the duty cycle. One of ordinary skill in the art would understand the implementation of such high-level and low-level divide ratios; therefore further details are not included herein.
[0077] It is to be understood that using clock generator 700 , a programmable serial port having a first FSM and a second FSM (e.g., programmable serial port 400 in FIG. 4) may be operated to achieve full duplex operation. Alternatively, clock generator 700 having a first FSM and a second FSM can be operated in half duplex mode having the transfer clock signal and the receive signal formed, such that transfers and receives occur on alternate clock intervals.
[0078] [0078]FIGS. 8A and B are timing diagrams for two exemplary clocking options. Each timing diagram illustrates a master clock 802 , a shift register control clock 804 , or 814 (i.e., a transfer clock signal or receive clock signal), and a corresponding FSM clock signal 806 , 816 . In addition, an indication 810 , or 820 is shown of the clock cycle during which Clock instructions are executed, along with an indication 805 , or 815 of the clock cycle during which the execution of the instruction occurs following the clock instruction (also referred to as the “next instruction”).
[0079] [0079]FIG. 8A illustrates an exemplary clock generator output for a clock generator generating one clock pulse in a standard mode. In a standard mode, an FSM clock signal 806 is generated during the time period when the shift register control clock signal 804 is generated. Accordingly, the instruction following the Clock instruction is executed during the master clock cycle 805 immediately following clock cycle 810 during which the Clock instruction is executed.
[0080] The exemplary timing diagrams correspond to a clock generator having a configuration register that is configured to achieve an off state 821 of one and a start state 823 of zero. Additionally, a duty cycle of one-quarter is achieved by selecting the low-level and high-level divide factors such that two of eight cycles are high.
[0081] [0081]FIG. 8B illustrates a clock generator output for a clock generator operating in a power-save mode. In a power-save mode, the FSM clock signal 816 is suspended while the shift register control clock signal 814 is generated. Power-save mode allows power consumption to be reduced. For example, power save mode may be used if a selected protocol does not require that instructions be executed while a shift register control clock is generated (i.e., while bits are output from a corresponding shift register).
[0082] Power-save mode is achieved by using gates 708 , 709 (shown in FIG. 7) to block output of an FSM clock signal while a corresponding shift register module provides an output. During the execution of a Clock instruction, if control registers 728 , 738 are configured in power-save mode, gates 708 and/or 709 block signals 705 and 706 , respectively, and upon completion of the appropriate number of cycles, gate 708 , 709 cease(s) to block the FSM clock signal.
[0083] In FIG. 8B, the shift register control signal 816 provides a shift register control clock 814 two periods in duration (as indicated by region 825 ). The clock signal has a duty cycle of thirty-three percent, an off state 822 of zero and a start state 824 of one.
[0084] Because decoding and execution of an instruction requires two clock cycles, execution of the next instruction occurs in the second clock cycle 815 after the end 830 of the shift register control clock signal 814 . (The decode of the next instruction occurs during the first clock cycle 831 following end 830 ) Accordingly, in some embodiments, a gate 708 and/or 709 may be controlled so as to cease blocking the FSM clock signal 816 one cycle before the end 830 of the shift register clock output. This allows the next instruction to be executed in the clock cycle immediately following completion of the shift register clock generation.
[0085] [0085]FIG. 9 is a flow chart 900 of an exemplary sequence of instructions for a programmable serial port according to some aspects of the present invention, to achieve a standard output (e.g., a UART compatible output). At step 905 , the FSM waits for an indication from the shift register that the shift register is full of data. At step 910 the FSM loads the driver with a start state. At step 920 , the bit counter is initialized. At step 930 , the FSM loads the bit counter in the shift register. The first data bit is sent and the logic value is held for as many clock cycles as necessary for the protocol, at step 950 . At step 960 , a clock command is sent to the clock generator defining the number of pulses and the division factor for the divider. Finally, the driver is set to a stop state at step 990 .
[0086] In contrast to the flow chart of the program for a conventional programmable serial port (described above with reference to FIG. 2), it is apparent the execution time necessary to achieve a given data output is significantly reduced according to the method and apparatus shown herein, because a reduced number of instructions need be executed by the FSM to provide a selected output. For example, in FIG. 2 the FSM was required to send a command to the shift register for each bit of data to be output (step 270 in FIG. 2). By contrast, in FIG. 9, a single command is sent to the clock generator (e.g., clock generator 360 in FIG. 3) to generate a predetermined number of pulses, at a rate determined by a divide rate. Because the clock generator is coupled to the shift register, the shift register outputs data bits in response to the clock pulses from the clock generator, thus relieving the FSM of the need to command the shift register to provide each data bit output. Also, in FIG. 2, the FSM decremented the bit counter (step 260 ) to maintain a numbered count of data bits that were output. By contrast in FIG. 9, the FSM is not required to execute an instruction to decrement a counter because the shift register has a bit counter that is decremented automatically in response to receiving a clock pulse from the clock generator. Additionally, the shift register is arranged to output a parity bit (if the protocol requires) and enter a stop state upon receipt of clock cycles after the bit bits have been sent, without need for the FSM to execute further instructions.
[0087] The following list of instructions is an exemplary instruction set to be executed by FSMs 410 and 411 (shown in FIG. 4). FIGS. 10A and 10B are tables illustrating one exemplary set of binary implementations of each of the instructions in the list. The list includes a functional description, as well as an explanation of the bits included in a corresponding binary implementation, for corresponding binary implementations 1000 illustrated in FIGS. 10A and 10B.
[0088] Because the binary implementation in FIGS. 10A and 10B is suitable for implementation with the decode and execution architecture in which selected instructions may be executed in parallel (described with reference to FIG. 10A below), some instructions in the following list correspond to two binary implementations, one each in FIG. 10A (for use in bit locations 0 - 7 ) and 10 B (for use in bit locations 15 - 8 ).
[0089] Referring to FIGS. 10A and 10B, each instruction is comprised of an operation code 1004 (indicated by logic values one and zero in binary implementations 1000 ) and one or more data fields and/or address fields.
[0090] The following list of instructions includes five types of instructions: configuration instructions, operation control instructions, flow control instructions, timing control instructions, clock control instructions, conditional instructions. Programmable serial bit ports may be implemented using FSMs having any known fetch, decode and execution scheme. For example, the instructions enumerated may be executed sequentially. In some embodiments, the instructions are executed in parallel as described below.
Configuration Instructions Brief Description Load Loads data to a specified register.
[0091] Referring to FIG. 10A ( 1002 ), the d values represent the value to be loaded and the i values indicate an address of register to be loaded.
Dual Bit Load Loads two selected bits of data to the driver or driver configuration registers.
[0092] Referring to FIGS. 10A and 10B ( 1004 a, 1004 b ), the i values indicate the bits in which the values are to be loaded, and v values represent the value to be loaded.
Mask Allows setting/resetting of selected bits of a selected register.
[0093] Referring to FIG. 10A ( 1006 ), the m values form the mask, and the i values represent the address of a register to be masked.
Map Used in combination with instructions having a finite number of address bits to increase the number of bits accessible in a given register using the instruction. For example, using the Map instruction, a selected instruction having a three- bit address field may select among greater than 8 bits; the Map instruction selects an eight 8-bit vector from within a register having greater than eight total bits and the three-bit address field selects a bit within the 8-bit vector. For example, Map may be used with the Conditional Execution instruction (discussed below) to select among 55 bits of the status register 495 (shown in FIG. 4A) despite the fact that in some embodiments the Conditional Execution register has only three-bit address field.
[0094] Referring to FIG. 10B ( 1008 ), the i values indicate a 8-bit vector.
Extend An extend command is used in combination with a another instruction (e.g., a Dual Bit Load or a Trigger) to provide an increased address field.
[0095] Referring to FIG. 10A ( 1010 ), the i values represent additional address bits.
Operation Control Instruction Trigger A trigger command enables an FSM to achieve a specified hardwired action by setting selected bits of output from an FSM. The action may be achieved directly or may be achieved indirectly (e.g., via a register hardwired to achieve the specified action).
[0096] Referring to FIGS. 10A and 10B ( 1012 a, 1012 b ), the i indicates the address of a hardwired register, and bi values indicate a specific bit within the register that corresponds to a particular action.
Flow Control Instructions Jump Absolute Jump to an absolute line of an instruction set
[0097] Referring to FIG. 10A ( 1014 ), the a values represent the destination address of the jump.
Jump Short Relative A relative jump, limited to a jump of a selected number of lines (e.g., 32 lines forward and 16 lines backward).
[0098] Referring to FIGS. 10A and 10B ( 1016 a, 1016 b ), the a values represent the number of program lines to be jumped.
Call Absolute Jump to an absolute address and store a return address in designated register.
[0099] Referring to FIG. 10A ( 1018 ), the a values represent the destination address of the jump.
Ret Return to address that was stored in a designated register during a Call Absolute
[0100] Illustrated as 1020 a and 1020 b in FIGS. 10A and 10B, respectively.
Software Reset Resets an FSM. In some embodiments, memory contents may be preserved.
[0101] Illustrated as 1022 a and 1022 b in FIGS. 10A and 10B, respectively.
Loop Performs a loop using a specified start address and a specified end address. The instructions between the start address and the end address are performed a number of times, as specified by a selected register.
[0102] Referring to FIG. 10A ( 1024 ), the o1 values indicates a start address and the o2 values indicate an end address for a loop. The number of iterations is fixed by a separate loop counter register.
Null A “filler” used to align sixteen-bit instructions in embodiments having a sixteen-bit fetches. Results in no execution. (Aspects of the Null instruction is described in greater detail below with reference to FIG. 10A.)
[0103] Illustrated as 1026 in FIG. 10B.
Timing Control Instructions Delay Delays execution of a next instruction a selected number of clock cycles. As described above, with reference to FIG. 4A, a delay may be executed using event counters 480, 81.
[0104] Referring to FIGS. 10A and 10B ( 1028 a, 1028 b ), the d values represent total delay length.
Long Delay Long delay operates the same as Delay except a the duration of the delay is selected using a pointer to a register rather than within the instruction itself. Accordingly, a longer delay period can be specified.
[0105] Referring to FIGS. 10A and 10B ( 1030 a, 1030 b ), the i values represent a pointer to a register having a total delay length.
Wait Waits until a specified condition is true (e.g., a condition specified using status register 495 and comparator 490 (see FIG. 4A). The FSM clock may be gated during execution of a Wait instruction using gates 708, 709.
[0106] Referring to FIG. 10A ( 1032 ), the c1 values indicate a first condition to be tested (e.g., an edge detect, a buffer full or empty), and the c2 values represent a second condition. The v1 and v2 values are values to be tested for, for the first condition and second condition, respectively. The mm values select the evaluation to be made for one or both the first condition and the second condition (e.g., an evaluation may include both condition c1 equal v1, and c2 equals v2).
Clock Control Instructions Clock Directs a selected clock divider to output a selected number of clock cycles, in standard or power-save mode depending on the clock configuration register.
[0107] Referring to FIG. 10A ( 1034 ), the cd values select a clock selection, and values d represent the number of pulses to be output.
Logical Instructions Conditional execution Execution of a specified instruction is conditioned on a selected condition.
[0108] Referring to FIG. 10A ( 1040 ), the i values represent the bit within a 8-bit vector the status register that forms the operand, and the v value represent the condition (1=true and 0=false). Typically used as a first byte of a 16-byte instruction; the second byte is the instruction to be executed if the condition is true.
Compare Data Compare data in a specified register to specified data value. The comparison may include a comparison based on at least the following operators: less than, greater than, equal to, etc.
[0109] Referring to FIG. 10A ( 1036 ), the i values indicate the register operating as the first operand. The d values indicate the data forming the second operand, and the cc values represent the comparison type (data=register, data 2 register, data 9 register).
Compare Registers Compare data in a specified register to data in another specified register.
[0110] Referring to FIG. 10A ( 1038 ), the i values indicate the register pair forming the first operand, and the second operand, and the cc values represent the comparison type (data=register, data 2 register, data 9 register).
[0111] Configuration register contents and instructions for implementing a protocol may be directly generated manually or compiled from a high level input using any suitable tools. An instruction sequence for use with programmable serial ports according to aspects of the present invention may be arranged in any suitable memory organization. FIG. 11A is a schematic illustration of one suitable memory organization 1100 suitable for use with present invention; memory organization 1100 accommodates the use of an instruction set including a combination of eight-bit and sixteen-bit instructions (as discussed above with reference to FIGS. 10A and 10B), and allows a sixteen-bit fetch to occur on each clock cycle without fetching partial instructions during a given fetch. Exemplary memory organization 1100 is comprised of lines of memory 1102 , 1104 , 1106 , 1108 ; each line of memory is divided into sixteen-bit segments.
[0112] In some embodiments, a first eight-bit instruction 1102 a is located in the eight-bit memory segments 1120 beginning at location 15 with the most significant bit at location 15 , and a second eight-bit instruction 1102 b is located in a next eight-bit memory segment 1135 (i.e., beginning at location 7 of line 1102 ). The second line of memory 1104 is occupied by a sixteen-bit instruction 1104 a.
[0113] Similar to first line 1102 , line 1104 has a first eight-bit instruction 1106 a located in eight-bit memory segments 1130 beginning at location 15 , with the most significant bit at location 15 . However, because the next instruction is a sixteen-bit instruction ( 1108 a ), the second instruction 1106 b in line 1106 is selected to be a Null instruction (described above), to avoid sixteen-bit fetches that include partial instructions (i.e., half of a sixteen-bit instruction). Accordingly, a compiler for use with such an architecture preferably inserts an eight-bit NULL instruction 1106 b in the eight-bit memory segments 1135 of line 1106 . Preferably, the Null instruction is a non-executed instructions (i.e., it is simply a placeholder instruction).
[0114] [0114]FIG. 11B is a schematic illustration of an exemplary FSM decode and execution architecture 1150 suitable for use with the memory organization 1100 of FIG. 11A. Decode and execution architecture 1150 includes a pre-decoder 1160 , and two decoders 1170 , 1175 .
[0115] As mentioned above, two-stage decode and execution architecture 1150 fetches sixteen bits of instruction on each clock cycle as described above. Using known techniques, pre-decoder 1160 , examines the operational codes of instruction(s) corresponding to a line of memory 1102 , 1104 , 1106 (visible in FIG. 11A above). Pre-decoder 1160 determines if the sixteen bits comprise a sixteen-bit instruction, two eight-bit instructions to be executed in parallel, or two eight-bit instructions to be executed serially.
[0116] The presence of an instruction illustrated in FIG. 10B located in memory location 1130 (for example, as determined by identifying its operation code) indicates that the eight-bit instructions in locations 1130 and 1135 are to be executed in parallel. The presence of any other instruction indicates the presence of a sixteen-bit instruction or two eight-bit instructions to be executed in parallel.
[0117] In the event that a particular line of memory 1102 , 1104 , 1106 (visible in FIG. 11A) includes a single sixteen-bit instruction, sixteen bits are provided to decoder 1170 ; in the event that a particular line of memory 1102 , 1104 , 1106 includes two eight-bit instructions to be executed serially, eight bits corresponding to the first instruction are provided on a first cycle and eight bits are provided on the next cycle such that the first instruction is executed on a first clock cycle and the second instruction is executed on the following clock cycle; and in the event that a particular line of memory 1102 , 1104 , 1106 includes two eight-bit instructions to executed in parallel, decoder 1170 receives the first instruction and decoder 1175 receives the second instruction on a first clock cycle.
[0118] Having thus described the inventive concepts and a number of exemplary embodiments, it will be apparent to those skilled in the art that the invention may be implemented in various ways, and that modifications and improvements will readily occur to such persons. Thus, the examples given are not intended to be limiting. The invention is limited only as required by the following claims and equivalents thereto. Also, it is to be understood that the use of the terms “including,” “comprising,” or “having” is meant to encompass the items listed thereafter and equivalents thereof as well as additional items before, after, or in-between the items listed.
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A high-speed programmable serial port having a finite state machine, a clock generator capable of controlling shifting of bits from a shift register and a shift register having a bit counter capable of maintaining a numbered count of data bits in a serial output. The clock generator and shift register reduce the burdens on a finite state machine, thus improving data throughput and the ability to provided data according to a multitude of data protocols.
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RELATED APPLICATIONS
This Application is a continuation-in-part of application Ser. No. 07/924,106, filed Aug. 3, 1992 abandoned which itself was a divisional of an application issued Nov. 3, 1992, as U.S. Pat. No. 5,161,098, and which had been filed Sep. 9, 1991 as Ser. No. 756,487.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to switching power supplies, or power converters, and more particularly to small, low cost switching power converters whose structural configuration permits automated assembly and elimination of a conventional transformer.
2. Description of the Prior Art
The consumer electronics revolution has resulted in a wide array of small, highly portable devices that typically run on batteries. For example, small Japanese televisions, radios, and CD players almost universally are supplied in the United States with earphones for private listening and AC power adaptors to save battery drain. If the device does not come with an AC adaptor, one is usually easily available, either from the original manufacturer or an after market supplier.
Two basic kinds of AC adaptors are ubiquitous, the linear type and the switching type. The linear type uses large 60 Hz transformers. FIG. 1 is a schematic of a typical prior art linear type AC adaptor which incorporates a 60 Hz transformer. The switching type uses a circuit to chop incoming power into high frequency pulses and can use very small and light transformers. FIG. 2 is a schematic of a relatively expensive prior art switching type power supply which feeds back voltage, current and/or power, in a closed loop control circuit, to regulate its output. Below ten watts, it has been more cost effective for manufacturers to supply the linear type AC adaptor, even though the 60 Hz step-down transformers can get quite bulky. At about ten watts, a cost-to-produce cross-over point is reached, and the more sophisticated switching type AC adaptors become cost effective. When switching type AC adaptors are used, the consumer benefits from the reduced size and weight of the unit that must be plugged into a wall plug.
Cost is a critical factor in being able to compete in the consumer electronics market. High performance is often not as important to consumers as low purchase cost. So manufacturers often choose to supply large and bulky 60 Hz transformers in plastic housings resembling bricks for their designs, even though smaller, lighter weight and more efficient designs are possible using switching power converters. One reason the linear type AC adaptor has a lower production cost is that the transformers used in switching type AC adaptors are difficult to assemble with automated equipment. Manual labor must be employed, and that lowers volumes and increases the per unit cost. Very often, the labor component in manufacturing costs is the biggest expense in producing power supplies under two watts.
Prior art linear type AC adaptors have efficiencies that reach only as high as fifty to sixty percent. A lot of power gets thrown-off as heat. These low efficiencies limit the power range of this type of power supply because the waste heat may make the unit too hot to handle, or dangerous to operate in certain situations.
Thus the prior art forces the designer or manufacturer of consumer electronic equipment to be faced with a choice between a heavy, large and inefficient linear power supply (which has a 60 Hz transformer) but which is inexpensive to produce, or a relatively light-weight, small-sized and very efficient .switched mode power supply that is expensive to produce. Generally, the choice is made in favor of the lower cost, large, heavy and inefficient power supply.
Randolph Shelly describes in U.S. Pat. No. 4,455,545, issued Jun. 19, 1984, an output inductor for high frequency inverter power supplies. A pair of channel-shaped ferrite core members are assembled with a gap of material approximating the permeability of air. The core members are arranged to provide an axial aperture in between. A plurality of conductor segments are positioned within the aperture and are electrically interconnected to plated through holes in a supporting printing circuit board assembly. The conductor turns for the inductor are selected for the inductor by the pattern of the printed circuit interconnections between selected plated-through holes.
K. B. A. Williams describes in U.S. Pat. No. 4,873,757, issued Oct. 17, 1989, a ferrite and thus permit magnetic induction and transformer action via the ferrite core.
Wolfgang Dirks describes in U.S. Pat. No. 4,975,671, issued Dec. 4, 1990, a multi-component transformer for use in conjunction with surface mount technology. Transformer windings are provided by a plurality of conductors arranged in parallel and disposed around a ferrite core. Another part of the windings is disposed in a spacer member or in tracings on a printed circuit card. A continuous loop of ferrite material is placed inside the windings.
Therefore a need exists for an AC adaptor technology that can provide the performance advantages of a switching type power supply, such as high efficiency, small size and light weight, while also providing the cost advantages of the sixty hertz transformer type power supplies. The present invention solves the problem of the expense of manufacturing a switching type power transformer by a novel method described below in detail.
SUMMARY OF THE PRESENT INVENTION
It is therefore an object of the present invention to provide a switching power supply that integrates both the primary and secondary windings of a switching transformer with a corresponding switching power supply control chip.
Briefly, a switching power supply embodiment of the present invention includes a plastic leaded chip carrier (PLCC) that has two rectangular holes joined by a channel on the bottom surface that allow the PLCC to be surface mounted on a printed circuit board over a ferrite U-core section. A ferrite I-core section caps the ends of the U-core section above the top surface of the PLCC. A wire frame within the PLCC provides for several individual parallel conductor segments that pass between the two holes to rows of surface mount pins on opposite edges of the PLCC. Traces on the printed circuit board complete the connection of these conductor segments to form a primary winding and a bias winding of a transformer. A secondary winding is similarly constructed using pins on another edge of the PLCC. A switched mode power supply integrated circuit chip is molded directly into the body of the PLCC nearer the primary winding conductor and chops current flowing in the primary winding according to a voltage derived from the current that results in the secondary winding.
An advantage of the present invention is that a switching power supply is provided that integrates both the transformer and IC in a switching power supply such that the transformer primary and secondary windings are molded in plastic with the chip IC.
Another advantage of the present invention is that an integrated transformer and IC for a switching power supply is provided that allows a higher number of turns on the transformer windings without necessitating the use of unusually small pin-to-pin spacings.
A further advantage of the present invention is that an integrated transformer and IC for a switching power supply is provided that allows a secondary winding of the transformer to be fully integrated.
Another advantage of the present invention is that an integrated transformer and IC for a switching power supply is provided that does not require extended printed circuit board to package pin lengths.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.
IN THE DRAWINGS
FIG. 1 is a schematic diagram of a prior art power supply that uses a sixty hertz transformer with a linear regulator;
FIG. 2 is a schematic diagram of a prior art power supply that uses a high frequency transformer and a pulse width modulated (PWM) switching control;
FIG. 3 is a perspective view of a dual-in-line IC package embodiment of the present invention for sandwiching between ferrite cores and mounting to a printed circuit board;
FIGS. 4A, 4B, and 4C are cross-sectional, top, and side views, respectively, of the embodiment of FIG. 3 and illustrate in particular the placement of the regulator chip within the package and its relationship to the leadframe and traces on the PCB. The cross-section of FIG. 4A is taken along the line 4A--4A of FIG. 4B;
FIG. 5 illustrates an alternative embodiment of the present invention which utilizes an inverted U-shaped insulated copper foil;
FIG. 6 shows a cut-away view of a power converter assembly embodiment of the present invention molded into the plug portion of an AC power cord;
FIGS. 7A and 7B are top and cross-sectional views respectively, of an alternative embodiment of the present invention that has the magnetic cores lying flat against a PC board. The cross-section of FIG. 7B has been taken along the line 7B--7B of FIG. 7A;
FIG. 8A is a perspective view of a plastic quad packaged switching power supply embodiment of the present invention as seen from a side that attaches to printed circuit board;
FIG. 8B is a top view of the quad packaged switching power supply of FIG. 8A;
FIG. 8C is a cross-sectional view of the quad packaged switching power supply of FIG. 8A taken along the lines 8C--8C in FIG. 8B;
FIG. 9A is a schematic representation of the lead frame wiring within the quad packaged switching powers supply of FIG. 8A;
FIG. 9B shows a portion of the lead frame wiring of FIG. 9A with a spiral wound secondary winding;
FIG. 10 is a simplified schematic diagram of a complete line-operated switching power supply with an isolated low-voltage DC output and includes the quad packaged switching power supply of FIG. 8A;
FIG. 11 shows the internal connections of the quad packaged switching power supply of FIG. 8A superimposed over a modified eighty-lead surface mount plastic flat pack; and
FIG. 12 shows the external connections to the quad packaged switching power supply of FIG. 8A on a typical printed circuit board substrate that have been superimposed over modified the eighty-lead surface mount plastic flat pack shown in FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 3, a system 10 comprises a ferrite U-core 12, an IC package 14, a ferrite I-core 16, a printed circuit board (PCB) 18 having a plurality of traces 20 on one side, a regulator chip 22, and a leadframe 24 of which the external portion visible on one side of IC package 14 is shown in FIG. 3. Regulator chip can alternatively be placed outside IC package 14 in a package of its own and mounted on PCB 18 proximate to leadframe 24. Traces 20 are on the bottom of PCB 18 and cannot be clearly shown in the perspective view of FIG. 3, so the reader is referred to FIGS. 4A and 4C. The connection ends of leadframe 24 can either have pins shaped for through-hole conventional mounting or bent surface mount technology (SMT) leads. The primary reasons to choose one type of mounting over the other are controlled by factors that are relatively unimportant to the functioning of the present invention and such choices are routinely made by those skilled in the art. The ferrite I-core and U-core are magnetic structural pieces having the respective "I" and "U" shapes, and are preferably high frequency types. The core materials are readily available from a number of suppliers, such as TDK and Siemens. Particular shapes and sizes may have to be custom made. In the preferred embodiment, one MHz cores are used and the U-core 12 is placed on the bottom so that leadframe 24 drops into a small well. The U-core 12 and I-core 16 can be swapped. IC package 14 is mounted on PCB 18 over ferrite U-core 12 that has been previously attached to the PCB 18. In a preferred embodiment, PCB 18 is a single-sided board having through-holes that need not be plated. (Plated through-holes in PCBs increase manufacturing costs.) A "one-sided" or "single-sided" PCB means the PCB has conductive traces on only one of its sides. Single-sided printed circuit boards are generally less expensive than those having multiple layers of interconnect, and so are preferred because lower cost is a principal goal of those who are expected to employ the present invention. The ferrite I-core 16 is mounted over the assembled components to complete a magnetic path.
As illustrated in FIGS. 4A, 4B, and 4C, prior to mounting I-core 16, a pre-formed insulated wire 26 is inserted to complete a secondary winding of a step-down transformer. Chip 22 and wire 26 are preferably at opposite ends from one another. In the preferred embodiment, pre-formed wire 26 is actually one of the wire leads of an axial-lead rectifier. Wire 26 acts as the transformer secondary, and is protected from shorts by an insulated sleeving 27 (e.g., wiring spaghetti). Alternatively, the secondary winding can be part of leadframe 24. However, using wire 26 insulated by sleeve 27 may be necessary to meet the requirements of electrical safety testing labs, such as Underwriters Laboratories (UL) for off-line applications. The primary and bias windings of the transformer thus created is formed from the combination and physical placement of the leadframe 24 and the plurality of conductive traces 20 on the PCB 18. The leadframe 24 has a chip mounting pad that is offset from the center so that regulator chip 22 can be mounted at one end of the leadframe 24. In this way, the remaining length of the leadframe 24 can be dedicated to forming a part of the primary and bias windings. The body of IC package 14 takes its final shape when leadframe 24 is encapsulated with an insulating material 28, such as plastic, after regulator IC 22 has been positioned within IC package 14. Additionally, in order to provide space for the high frequency ferrite core underneath the IC package 14, either the leads may be cut slightly longer than usual, or the encapsulating plastic may be made slightly thinner than usual. There may be a gap 28 of material approximating the permeability of air between the I-core 16 and U-core 12 to adjust the magnetic properties of the resulting transformer. The typical number of turns in the primary winding of the present invention is ten to twenty and bias winding is three to four. In the secondary winding, one to two turns is typical.
The number of primary and bias winding turns can be programmed by manipulating the number of leadframe 24 connections to conductive traces 20 on PCB 18. Fewer turns obviously requires the use of less material and space. However, a lower number of turns means that higher switching frequencies are required to achieve the same power supply electrical performance. A lower number of turns also reduces the value of equivalent loss resistance across the winding due to the relatively high conductivity of ferrite cores. This effect alone limits the number of turns to no less than ten for currently available high frequency core material.
For lower leakage inductance, an I-core 30 (similar to I-core 16) and an inverted U-shaped insulated copper foil 32 cover an entire chip, as shown in FIG. 5. The foil 32 itself reduces the leakage inductance. This embodiment, however, requires the use of a surface mounted chip 34 (as opposed to a DIP IC), a U-core 36, a thin insulator 38, and a two-sided PCB 40. In this embodiment, the two-sided PCB 40 would provide one layer, the top side, for programming the number of primary winding turns, and the second layer, the bottom side, to complete the circuit for the secondary. Ferrite cores 30, 36 are used to provide the magnetic pathway. The thin material of insulator 38 is placed between the conductive traces on the top of the PCB 40 and ferrite U-core 36.
The small size of the AC adaptor of the present invention provides the opportunity to mold the assembly into the plug portion of an AC power cord. This market-enhancing product feature could be achieved using well-known plastic molding techniques, once the structural configuration of the present invention has been fabricated.
An example of this application of the present invention is shown in FIG. 6. An AC power cord, designated generally by reference numeral 50, is shown with part of the plug portion cut-away.
In operation, AC power is applied to a pair of prongs 52, which extend outward from an insulated plug portion 54. Within the plug portion 54, AC power is electrically coupled to an AC adaptor 58 assembled by the method of the present invention. The DC output of AC adaptor 58 is electrically coupled to a pair of conductive leads 60 which are embedded within an insulator 62.
FIGS. 7A and 7B illustrate an alternative embodiment of the present invention, an AC adaptor 70 that has a magnetic core 72 that lies flat against a PC board 74. The advantage of AC adaptor 70 is that assembly is simplified, since the magnetic core 72 can be a single piece that is simply glued down to the PC board 74 before a DIP package 76 containing several transformer windings and a semiconductor chip, as described above, is soldered in. In applications that allow a non-isolated secondary winding or lower level of isolation between primary and secondary (low voltage DC-to-DC converting), both the primary and secondary windings can be contained in DIP package 76. This technique allows the secondary wire, such as wire 26 and sleeving 27 in FIG. 4B, to be eliminated. A regulator chip 78 can either be disposed within DIP package 76 or mounted on PC board 74 proximate to a lead frame 80. FIGS. 7A and 7B show the regulator chip 78 within DIP package 76 here merely for purposes of illustration of an acceptable location. Both a secondary and a primary winding are contained in leadframe 80. A plurality of connections 82 complete the primary coil comprised of lead frame 80.
An alternative embodiment of the present invention is illustrated in FIGS. 8A-8C. A quad in-line packaged switching power supply 100 comprises a molded plastic package 102 that is flat and rectangular in shape and has a pair of rectangular holes 104 and 106 and a channel 108 that permit a U-core ferrite section 110 to pass through package 102 to couple with an I-core ferrite section 112. A circular magnetic path is created when U-core 110 is capped by I-core 112. A material that approximates the permeability of air may alternatively be inserted at one or two places between the I-core 112 and U-core 110 to adjust the magnetic properties of the assembled core. A switching power supply integrated circuit (IC) chip 114 is molded into package 102. An alternative location 116 may be provided for chip 114, including a location outside the package and on the printed circuit board. A set of three rows of surface mount technology (SMT) pins 118-120 are provided for a primary and a bias transformer winding. A single row of SMT pins 121 are provided for a secondary transformer winding that is magnetically coupled to the primary transformer winding by U-core 110 and I-core 112.
FIG. 9A illustrates a leadframe wiring diagram for power supply assembly 100, which is intended to be mounted on a printed circuit board that has traces that complete an interconnection between pin row 118 and half of pin row 119 underneath U-core 110 to pin row 120 and the other half of pin row 119 such that a multiple turn primary and bias windings are completed. Similarly, half of pin row 121 is connected by the traces on the printed circuit board underneath U-core 110 to the other half of pin row 121 such that a single multiple turn secondary winding is completed. The plastic body of package 102 provides insulation between winding turns, between the secondary and primary windings, and between the chip 114 and both windings. A larger than usual spacing between pins in pin row 121 and the pins in both of pin rows 118 and 120 provides a minimum creepage distance that may be required to meet various government and testing laboratory standards in the world. FIG. 9A illustrates two separate conductors proximate to hole 106 that may be connected by patterned traces of a printed circuit board to form a single wire that winds around U-core 110.
In FIG. 9B, these conductors are formed into a single spiral and brought out to only two pins on pin row 121 with a bonding wire jumper. In such a case, the number of turns would be fixed, but the completion of the turns by printed circuit board traces would be unnecessary.
FIG. 10 illustrates a complete switching power supply system 130 that includes power supply assembly 100. System 130 further includes a fuse 132, a bridge configuration of rectifiers 134-137, a pair of chokes 138 and 140, a pair of filter capacitors 142 and 144, and a snubber network 146. An isolated five volt output is provided by a diode 148 and a filter capacity 150 that are coupled to the secondary transformer winding that is partially disposed in assembly 100 and a printed circuit board upon which system 130 is constructed using surface mount technology. An op-amp 152 compares the voltage output of the isolated five volt output section to a voltage reference (V ref ) and drives a light emitting diode (LED) 154 in response. The voltage output of the isolated five volt output section is a function of the current being induced from the primary winding into the secondary winding. Therefore, a feedback path is provided for controlling the chopping of current flowing through the primary winding by an IC (e.g., 114) within assembly 100. For isolation, this feedback path includes the light output of LED 154 which is optically coupled to the base of a photo-transistor 156. The emitter of photo-transistor 156 then is able to control assembly 100, e.g., by a single lead wire.
A non-isolated bias voltage output is provided by assigning some of the conductors in assembly 100 for the primary winding to serve as a second primary or a bias winding which can also provide a non-isolated secondary output. A diode 158 rectifies the current and a capacitor 160 does the filtering. For example, a nominal output voltage of 7.5 volts may be produced by such a section. An AC line voltage input of 110-220 volts may be input to power supply 130. The voltages cited here are typical, but not limiting of the invention. Other input and output voltage combinations are feasible and may be desirable, depending on the application.
FIG. 11 shows the internal connections of assembly 100 superimposed over a modified eighty-lead surface mount plastic flat pack.
FIG. 12 shows the external connections to assembly 100 on a typical printed circuit board substrate that have been superimposed over modified eighty-lead surface mount plastic flat pack shown in FIG. 11.
Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that the disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the invention.
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A switching power supply embodiment of the present invention includes a plastic leaded chip carrier (PLCC) that has two rectangular holes joined by a channel on the bottom surface that allow the PLCC to be surface mounted on a printed circuit board over a ferrite U-core section. A ferrite I-core section caps the ends of the U-core section above the top surface of the PLCC. A wire frame within the PLCC provides for several individual parallel conductor segments that pass between the two holes to rows of surface mount pins on opposite edges of the PLCC. Traces on the printed circuit board complete the connection of these conductor segments to form a primary winding of a transformer. A secondary winding is similarly constructed using pins on another edge of the PLCC. A switched mode power supply integrated circuit chip is molded directly into the body of the PLCC nearer the primary winding conductor and chops current flowing in the primary winding according to a voltage derived from the current that results in the secondary winding.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 14/451,569, filed Aug. 5, 2014. The aforementioned related patent application is herein incorporated by reference in its entirety.
BACKGROUND
[0002] The present invention relates to computer software, and more specifically, to computer software to perform actions on objects as a result of applying tags to the objects.
[0003] Tags have traditionally been used to organize files and other computing resources. Tags are typeless, in that a user may assign any type of meaning to any tag, without computer software understanding what the tag signifies. However, simply tagging an object does not cause the object to comply with the meaning of the tag.
SUMMARY
[0004] Embodiments disclosed herein include systems, methods, and computer program products to tag objects in a cloud computing environment, by tagging an object with a first tag, of a plurality of tags, wherein each of the plurality of tags specifies a respective criterion for objects tagged by each tag, and upon determining that the object not satisfy the criterion of the first tag, performing an action associated with the first tag to modify the object to meet the criterion of the first tag.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0005] FIG. 1 depicts a graphical user interface to perform actions on objects as a result of applying tags to the objects, according to one embodiment.
[0006] FIG. 2 depicts a system to perform actions on objects as a result of applying tags to the objects, according to one embodiment.
[0007] FIG. 3 depicts a method to perform actions on objects as a result of applying tags to the objects, according to one embodiment.
[0008] FIG. 4 depicts a method to perform actions associated with a tag, according to one embodiment.
[0009] FIG. 5 depicts a graphical user interface to use tags in an infrastructure lifescycle, according to one embodiment.
[0010] FIG. 6 depicts a cloud computing node according to an embodiment of the present invention.
[0011] FIG. 7 depicts a cloud computing environment according to an embodiment of the present invention.
[0012] FIG. 8 depicts abstraction model layers according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0013] Embodiments disclosed herein associate textual tags with specific actions, such that when the tag is applied to computing objects, the actions are run in order to configure the object (or dependent objects) to comply with the tag. Tags may be applied directly to objects in a cloud computing environment, such as a computing resource or a workload to be deployed in the cloud computing environment. The computing resource may be hardware, software, or any combination thereof. The workload may be tagged with specific resource requirements, such that the resources targeted by the tagging are configured to be in compliance with the tag's criteria.
[0014] A tag, as used herein, refers to a textual metadata classifier that annotates (or classifies) an object with a set of criteria. Furthermore, a tag, as used herein, may provide an associated set of actions that cause tagged objects to comply with the criteria, if the tagged objects do not already comply with the criteria. If the tagged objects already comply with the criteria, the objects may be classified without acting on them. The tags may coexist with conventional tags in the same namespace. As used herein, an object may refer to, without limitation, any computing resource (software, hardware, or both), workflow, or workload.
[0015] For example, a user may define a “grayscale” tag that causes digital photographs and other digital images to be processed so that they have a grayscale color depth, if they don't have the grayscale color depth already. The user may associate the grayscale tag with a script that is configured to apply grayscale color depth to the digital images. When a user subsequently tags a digital photograph with the grayscale tag, the script may be invoked to convert the digital photograph from color to grayscale. As another example, a user may define an “EnergySaver” tag that may initiate actions and policies to adjust power capping, energy usage, and migrate virtual machines in order to shut down servers to save energy. When the user tags a virtual machine image with the EnergySaver tag, subsequent deployments of the virtual machine image will be deployed to a cloud computing configuration that complies with the predefined power saving techniques and requirements.
[0016] In any case, tagging objects as disclosed herein may be used to not only classify objects, but to configure objects so that they are altered to reflect the tag's meaning, and to specify requirements for workloads that have not yet deployed. Embodiments disclosed herein allow users, who tag existing resources with a specific purpose (as defined by the tag), to configure new resources for the same specific purpose without having to run complex actions and configurations each time. Furthermore, since tagging is used for classification and filtering, embodiments disclosed herein allow users to use the tag to understand which resources comply with the tag, as well as which resources are being configured to comply with the tag. The tag may specify any requirement, including, without limitation, as minimum resource allocations, operating parameters or environment, security parameters, virtual resource configurations, quality of service, class of service, and the like.
[0017] FIG. 1 depicts a graphical user interface (GUI) 100 to perform actions on objects as a result of applying tags to the objects, according to one embodiment. As shown, the GUI 100 lists different resources in a cloud computing environment. In this example, the resources are the objects to which tags are applied. Each resource includes a name 101 , a type 102 , a category 103 , and a set of tags 104 . The name 101 may be a name of a resource, such as the servers 1 - 3 , and the workflow 1 . The type 102 indicates a type of the resource, such as an x86 computer, Power7 server, or disk image. The category 103 indicates a category the resource belongs to, such as compute node or image. Although depicted to facilitate explanation of the disclosure, the type 102 and the category 103 are not required to enable tagging of an object. A tag may be applied to any label or identifier sufficient to uniquely identify an object. The tags 104 are a set of user-defined tags that have been applied to the object, in this example, servers and a workflow. The tags may be associated with a specified set of criteria and a set of actions that alter the resource to make the object comply with the set of criteria. Generally, a user may define any number and type of tags for any object. When a user wishes to apply a tag to an object, the user may apply any feasible method to apply the tag. As shown, for example and without limitation, a user is typing a tag 105 , which is the DualVIOS tag. A popup notification 106 indicates that the user may apply the tag by pressing enter. The user may define the DualVIOS tag to be associated with two redundant virtual I/O servers. In defining the DualVIOS tag, a user may specify one or more criteria and associated actions. In one embodiment, the user may tag existing scripts used to deploy the dual virtual I/O servers, configuration patterns, or other templates that contain configuration information for the dual virtual I/O servers. Additionally, workflow images may be tagged, thereby specifying specific criteria that need to be present in order for the workload to be deployed in a data center.
[0018] Generally, when a user tags an object, embodiments disclosed herein may reference a data store of existing tags to determine if the tag has previously been defined. If the tag has not been defined, the user may specify the criteria and associated actions that cause different objects to comply with the tag. As such, users can apply previously defined tags, as well as create tags in a freestyle and ad hoc manner. If the tag has already been defined, the criteria and actions may be retrieved in order to ensure that the object complies with the tag.
[0019] When the user enters the tag 105 , embodiments disclosed herein may analyze server 3 to determine whether the server is compliant with the tag. To determine if server 3 is compliant with the DualVIOS tag, the tag requirements may be compared against the current configuration of server 3 . For example, a data store reflecting the status, capabilities, and configuration of server 3 may be referenced to identify whether it currently is executing (or is capable of executing) the dual virtual I/O servers. Additionally or alternatively, the resource (server 3 ) may be queried directly (or through a proxy, such as a management controller) to determine if server 3 is executing the dual virtual I/O servers. If server 3 is not currently executing dual redundant virtual I/O servers, embodiments disclosed herein may initiate a predefined set of actions to deploy the dual virtual I/O servers onto server 3 . A user may optionally be prompted to approve the changes to server 3 prior to deploying the dual virtual I/O servers.
[0020] As another example, as shown, workflow 1 has also been tagged with the DualVIOS tag 104 , as the workflow requires the two virtual I/O servers to run properly. When workflow 1 is subsequently deployed in a cloud computing environment, embodiments disclosed herein may enforce the DualVIOS tag 104 by ensuring the deployments include the dual virtual I/O servers. If, for example, active host servers having the dual virtual I/O servers configured, embodiments disclosed herein may deploy the workflow 1 to one or more of such active host servers. If active host servers are not found running dual virtual I/O servers (or that are capable of hosting dual virtual I/O servers), embodiments disclosed herein may scan other resources to find host servers in stand-by or other low priority pools that are compatible. This compatibility may be determined, as discussed above with reference to server 3 , by referencing stored information of the stand-by servers, or retrieving the capabilities and current configuration of the stand-by servers directly (or by proxy). Once a compatible server is identified as a target, embodiments disclosed herein may tag the resource with the DualVIOS tag, which initiates the re-configuration of the server to include the dual virtual I/O servers. Once the configuration of the servers is complete, the workload may be deployed to the target server.
[0021] Generally, users may define any type of tag specifying any number and type of criteria, as well as any associated actions. As another example, a user may tag a compute node with a “PowerVC1” tag, which causes the node to be registered with a management application named “PowerVC1.” Appending the tag DualVIOS to the compute node tagged PowerVC1 would cause the node to be added to the hardware management console (HMC3), installing two virtual I/O servers on the tagged node, and then adding the node into the PowerVC1 management application.
[0022] FIG. 2 depicts a system to perform actions on objects as a result of applying tags to the objects, according to one embodiment. The networked system 200 includes a computer 202 . In at least one embodiment, the networked system 200 is a cloud computing environment. The computer 202 may also be connected to other computers via a network 230 . In general, the network 230 may be a telecommunications network and/or a wide area network (WAN). In a particular embodiment, the network 230 is the Internet.
[0023] The computer 202 generally includes a processor 204 connected via a bus 220 to a memory 206 , a network interface device 218 , a storage 208 , an input device 222 , and an output device 224 . The computer 202 is generally under the control of an operating system (not shown). Examples of operating systems include the UNIX operating system, versions of the Microsoft Windows operating system, and distributions of the Linux operating system. (UNIX is a registered trademark of The Open Group in the United States and other countries. Microsoft and Windows are trademarks of Microsoft Corporation in the United States, other countries, or both. Linux is a registered trademark of Linus Torvalds in the United States, other countries, or both.) More generally, any operating system supporting the functions disclosed herein may be used. The processor 204 is included to be representative of a single CPU, multiple CPUs, a single CPU having multiple processing cores, and the like. The network interface device 218 may be any type of network communications device allowing the computer 202 to communicate with other computers via the network 230 .
[0024] The storage 208 may be a persistent storage device. Although the storage 208 is shown as a single unit, the storage 208 may be a combination of fixed and/or removable storage devices, such as fixed disc drives, solid state drives, SAN storage, NAS storage, removable memory cards or optical storage. The memory 206 and the storage 208 may be part of one virtual address space spanning multiple primary and secondary storage devices.
[0025] The input device 222 may be any device for providing input to the computer 202 . For example, a keyboard and/or a mouse may be used. The output device 224 may be any device for providing output to a user of the computer 202 . For example, the output device 224 may be any conventional display screen or set of speakers. Although shown separately from the input device 222 , the output device 224 and input device 222 may be combined. For example, a display screen with an integrated touch-screen may be used.
[0026] As shown, the memory 206 contains a tag application 212 , which is an application generally configured to apply user-defined tags to computing objects, and cause user-defined actions to be applied to tagged objects. Generally, users may define any types of tags, which may be stored in the tag data 215 . If the user creates a tag that has not been previously defined, the user may specify the tag criteria and any associated actions that may be performed in order to cause tagged objects to comply with the tag criteria. When a user applies a tag to an object, such as hardware, software, or a combination thereof, the tag application 212 may identify the tag criteria, and compare the criteria to the tagged object. The object properties may be stored in the object properties 217 , or the object properties may be retrieved by querying a resource, or an application managing the resource. If the object complies with the criteria, the tag application 212 , in some cases, may not take any further action. If the object does not comply with the tag criteria, the tag application 212 may perform one or more predefined actions to bring the object into compliance with the tag. The actions associated with the tag may be stored in the action items 216 . For example, if a user tags a server as “webserver,” the tag application 212 may identify the corresponding tag in the tag data 215 , identify any action items 216 (user defined or otherwise) that cause a server to be configured as a web server, and execute the steps necessary to configure the server to host a web server. Additionally, the tag application 212 may group objects with common criteria together.
[0027] As shown, storage 208 contains the tag data 215 , action items 216 , and object properties 217 . The tag data 215 contains a plurality of tags that may be applied directly to an object, such as a computing resource or a workload that targets computing resources. The tags in the tag data 215 may be associated with specific criteria and a set of actions that may alter a resource to comply with the tag criteria. The action items 216 is a repository of computer-executable code, scripts, or other configuration methods that may alter objects in order to make the resources comply with different tag criteria. In at least one embodiment, the action items 216 may themselves be tagged with tags from the tag data 215 . Similarly, the tag data 215 may specify associated items in the action items 215 . Doing so associates the tags in the tag data 215 with predefined actions in the action items 216 , which allows the tag application 212 to ensure that objects are configured according to the tag criteria. The object properties 217 is a store configured to hold configuration information and other attributes of objects in the system 200 . The object properties 217 may generally include configuration and attributes of computing resources or workflows. For example, hardware configurations, software configurations, and other information about one or more hosts 250 , virtual machines, and other computing resources may be defined. In addition, the object properties 217 may also specify each tag that has been applied to each object.
[0028] The hosts 250 are compute nodes which perform different computing functions. For example, the hosts 250 may be configured to execute one or more virtual machines 261 , or store data in storage locations 262 . In one embodiment, the hosts 250 may be compute nodes in a cloud computing environment.
[0029] FIG. 3 depicts a method 300 to perform actions on objects as a result of applying tags to the objects, according to one embodiment. Generally, the steps of the method 300 run a set of predefined actions when a user applies a textual tag directly to a resource, or in reaction to a workflow or workload being deployed that is tagged with specific resource requirements, such that the resources targeted by the tagging are configured to be in compliance with the tag criteria. In at least one embodiment, the tag application 212 performs the steps of the method 300 .
[0030] At step 310 , a user may define tag attributes, criteria, and associated actions that are performed responsive to a user tagging an object with the tag. For example, a user may define a “SecurityCertified” tag, which may specify a set of security parameters for a hardware object, software object, or combination thereof. The tag attributes and criteria may be stored in the tag data 215 . The user may further specify actions associated with the tag, such as applying security to communications transmitted by the object, configuring firewalls, and the like. The associated actions may be stored in the action items 316 . At step 320 , the tag application 212 may receive user input tagging an object with a tag. Generally, the user may tag any object in a computing environment with a tag, such as a computer, networking device, software image, files in storage locations, and the like. For example, the user may tag a compute node (i.e., a server) in a cloud computing environment with the SecurityCertified tag. The tag application 212 may also store the tag in a record for the tagged object in the object properties 217 , reflecting that the tag has been applied to the object. At step 330 , the tag application 212 compares the tag criteria, which may be stored in the tag data 215 , to the object's current configuration. The tag application 212 compares the object properties to the criteria in order to determine whether the object complies with the tag criteria. For example, the tag application 212 may determine whether the server, tagged with the SecurityCertified tag, complies with the predefined attributes and criteria of the SecurityCertified tag. The tag application 212 may retrieve the server properties and configuration information from the object properties 217 , the server itself, or a proxy, such as a management controller that manages the server.
[0031] At step 340 , the tag application 212 , upon determining that the tag criteria are not met, performs the actions associated with the tag in order to cause the object to comply with the tag. The associated actions may be, without limitation, a script, set of actions, or other configuration methods that may alter objects to make the object comply with the tag criteria. For example, the tag application 212 may cause firewalls to be configured, enable encryption on the server, and the like. Generally, the tag application 212 may cause any action to be taken to configure the tagged object, or resources that the tagged object targets.
[0032] As an example involving tagging a workload, the user may apply the SecurityCertified tag to a workload image. When the workload is subsequently deployed, the tag application 212 may ensure that the resources the workload is deployed to comply with the SecurityCertified tag. For example, the tag application 212 may identify resources that comply with the SecurityCertified tag attributes. If the tag application 212 does not find any matching (tagged) resources, the tag application 212 may automatically tag the existing resources to cause existing resources to be reconfigured to comply with the tags. Once SecurityCertified resources are configured, the SecurityCertified workload may be deployed to the resources for processing.
[0033] FIG. 4 depicts a method 400 corresponding to step 340 to perform actions associated with a tag, according to one embodiment. Generally, the steps of the method 400 result in the reconfiguration of resources such that the resources comply with the tags applied to different objects. The tagged objects may be resources, data, or any combination of hardware or software. Additionally, the tagged objects may be workflows targeting different computing resources in a cloud computing environment.
[0034] At step 410 , the tag application 212 may optionally prompt for user approval prior to triggering the actions to change the computing resources affected by the tags applied by the user. At step 420 , the tag application 212 may generally invoke any associated scripts, patterns, or other templates that include configuration information designed to bring tagged objects into compliance with the tag criteria. For example, if a user tags a file as PasswordProtected, the tag application 212 may invoke a script which applies a password to the file. The script may apply a default password, or prompt a user to specify the password. If the object is a resource, the tag application 212 , by the invoked actions at step 420 , causes the resource to be configured to comply with the tag criteria at step 430 . If the tagged object is a workload, at step 440 , the tag application 212 may identify existing targets (such as compute nodes) satisfying tag requirements. If the tag application 212 finds no such existing resources, the tag application 212 may identify existing resources capable of meeting tag criteria. The tag application 212 may then tag these resources such that they are reconfigured to meet the tag criteria. At step 450 , if the tagged object is an item in storage, the tag application 212 causes the item in storage to be modified to meet tag criteria. For example, if a user tags a digital photograph with a specified image format, the tag application 212 may invoke the necessary actions to convert the photograph to the specified image format. Generally, the tag application 212 may invoke any number of actions in order to cause the object to meet any number of criteria specified in the tag.
[0035] FIG. 5 depicts a graphical user interface 500 to use tags in an infrastructure lifescycle, according to one embodiment. Generally, applying tags to objects in a computing environment allows the tags to be leveraged in order to manage the computing environment. In some computing environments, hundreds of thousands, if not millions of objects, need to be managed. As shown, the GUI 500 provides a set of tags 510 that a user can select in order to filter the resources down to only those resources having the specified tag. Therefore, when the user selects the Website tag 512 , only those resources tagged with the Website tag may be displayed. In addition, a set of tools and actions scoped to the selected tag may be displayed. For example, and without limitation, elements 511 and 512 allow a user to deploy a Website workload and add website resources, respectively. When the user selects the elements 511 or 512 , any added resources or workloads would be tagged with “Website,” and any hardware configuration to make the newly added hardware compliant with the Website tag would be performed automatically. In addition, different management tools 520 , 530 , 540 , 550 , and 560 allow users to view management providers, workload statuses, workloads with issues, hardware maps, and capacity/policies related to the selected tag, respectively. Generally, the tools 520 - 560 are small views that summarize different categories of objects so that in one dashboard, many kinds of objects can be seen in summary. For example, if a user clicks “Website,” the user instantly sees any object tagged with Website. In addition, in tool 520 , the user would see how many hardware management consoles and how many virtual management consoles are involved in managing the web sites. In tool 530 , the user would visualize how many workloads in the datacenter are contributing to the web sites. In tool 540 , the user would see how many workloads contributing to web sites have problems. Using tool 550 , the user would see what actual hardware components (computers, storage, network) are supporting the web sites. Finally, using tool 560 , the user would receive an aggregate ‘utilization’ view highlighting how many resources and what kinds of policies are manipulating the web sites.
[0036] Advantageously, embodiments disclosed herein provide textual tags that are associated with predefined criteria and actions, such that when the tags are applied to objects in a computing environment, the actions are executed in order to configure the object (or dependent objects), such that the object complies with the tag. The tags may be applied to physical or virtual resources, software, data, and any other component in a computing environment. By defining a tag, users can configure items without substantial effort. Tagging, which is a universal way to classify objects, may therefore be extended to configure objects such that they are altered to reflect the tag's meaning. Furthermore, the tags may specify requirements for workloads that have not yet been deployed. When the workload is subsequently deployed, the workload may be deployed to underlying resources that comply with the tag criteria.
[0037] It is understood in advance that although this disclosure includes a detailed description on cloud computing, implementation of the teachings recited herein are not limited to a cloud computing environment. Rather, embodiments of the present invention are capable of being implemented in conjunction with any other type of computing environment now known or later developed.
[0038] For convenience, the Detailed Description includes the following definitions which have been derived from the “Draft NIST Working Definition of Cloud Computing” by Peter Mell and Tim Grance, dated Oct. 7, 2009, which is cited in an IDS filed herewith, and a copy of which is attached thereto.
[0039] Cloud computing is a model of service delivery for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g. networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be rapidly provisioned and released with minimal management effort or interaction with a provider of the service. This cloud model may include at least five characteristics, at least three service models, and at least four deployment models.
[0040] Characteristics are as follows:
[0041] On-demand self-service: a cloud consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with the service's provider.
[0042] Broad network access: capabilities are available over a network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).
[0043] Resource pooling: the provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to demand. There is a sense of location independence in that the consumer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter).
[0044] Rapid elasticity: capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.
[0045] Measured service: cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service.
[0046] Service Models are as follows:
[0047] Software as a Service (SaaS): the capability provided to the consumer is to use the provider's applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based e-mail). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
[0048] Platform as a Service (PaaS): the capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including networks, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations.
[0049] Infrastructure as a Service (IaaS): the capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls).
[0050] Deployment Models are as follows:
[0051] Private cloud: the cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on-premises or off-premises.
[0052] Community cloud: the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on-premises or off-premises.
[0053] Public cloud: the cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
[0054] Hybrid cloud: the cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds).
[0055] A cloud computing environment is service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability. At the heart of cloud computing is an infrastructure comprising a network of interconnected nodes.
[0056] Referring now to FIG. 6 , a schematic of an example of a cloud computing node is shown. Cloud computing node 610 is only one example of a suitable cloud computing node and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. Regardless, cloud computing node 610 is capable of being implemented and/or performing any of the functionality set forth hereinabove.
[0057] In cloud computing node 610 there is a computer system/server 612 , which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system/server 612 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like.
[0058] Computer system/server 612 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server 612 may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.
[0059] As shown in FIG. 6 , computer system/server 612 in cloud computing node 610 is shown in the form of a general-purpose computing device. The components of computer system/server 612 may include, but are not limited to, one or more processors or processing units 616 , a system memory 628 , and a bus 618 that couples various system components including system memory 628 to processor 616 .
[0060] Bus 618 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnects (PCI) bus.
[0061] Computer system/server 612 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server 612 , and it includes both volatile and non-volatile media, removable and non-removable media.
[0062] System memory 628 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 630 and/or cache memory 632 . Computer system/server 612 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 634 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus 618 by one or more data media interfaces. As will be further depicted and described below, memory 628 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.
[0063] Program/utility 640 , having a set (at least one) of program modules 642 , may be stored in memory 628 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 642 generally carry out the functions and/or methodologies of embodiments of the invention as described herein.
[0064] Computer system/server 612 may also communicate with one or more external devices 614 such as a keyboard, a pointing device, a display 624 , etc.; one or more devices that enable a user to interact with computer system/server 612 ; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server 612 to communicate with one or more other computing devices. Such communication can occur via I/O interfaces 622 . Still yet, computer system/server 612 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter 620 . As depicted, network adapter 620 communicates with the other components of computer system/server 612 via bus 618 . It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server 612 . Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.
[0065] Referring now to FIG. 7 , illustrative cloud computing environment 750 is depicted. As shown, cloud computing environment 750 comprises one or more cloud computing nodes 610 with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone 754 A, desktop computer 754 B, laptop computer 754 C, and/or automobile computer system 754 N may communicate. Nodes 610 may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described hereinabove, or a combination thereof. This allows cloud computing environment 750 to offer infrastructure, platforms and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices 754 A-N shown in FIG. 7 are intended to be illustrative only and that computing nodes 610 and cloud computing environment 750 can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser).
[0066] Referring now to FIG. 8 , a set of functional abstraction layers provided by cloud computing environment 750 ( FIG. 7 ) is shown. It should be understood in advance that the components, layers, and functions shown in FIG. 8 are intended to be illustrative only and embodiments of the invention are not limited thereto. As depicted, the following layers and corresponding functions are provided:
[0067] Hardware and software layer 860 includes hardware and software components. Examples of hardware components include mainframes, in one example IBM® zSeries® systems; RISC (Reduced Instruction Set Computer) architecture based servers, in one example IBM pSeries® systems; IBM xSeries® systems; IBM BladeCenter® systems; storage devices; networks and networking components. Examples of software components include network application server software, in one example IBM WebSphere® application server software; and database software, in one example IBM DB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter, WebSphere, and DB2 are trademarks of International Business Machines Corporation registered in many jurisdictions worldwide)
[0068] Virtualization layer 862 provides an abstraction layer from which the following examples of virtual entities may be provided: virtual servers; virtual storage; virtual networks, including virtual private networks; virtual applications and operating systems; and virtual clients.
[0069] In one example, management layer 864 may provide the functions described below. Resource provisioning provides dynamic procurement of computing resources and other resources that are utilized to perform tasks within the cloud computing environment. Metering and Pricing provide cost tracking as resources are utilized within the cloud computing environment, and billing or invoicing for consumption of these resources. In one example, these resources may comprise application software licenses. Security provides identity verification for cloud consumers and tasks, as well as protection for data and other resources. Tagging allows users to tag objects in the cloud computing environment and cause the objects to conform to the applied tags, as described in greater detail above. Service level management provides cloud computing resource allocation and management such that required service levels are met. Service Level Agreement (SLA) planning and fulfillment provide pre-arrangement for, and procurement of, cloud computing resources for which a future requirement is anticipated in accordance with an SLA.
[0070] Workloads layer 866 provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation; software development and lifecycle management; virtual classroom education delivery; data analytics processing; transaction processing; and mobile desktop.
[0071] The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
[0072] As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
[0073] Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
[0074] A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
[0075] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
[0076] Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0077] Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0078] These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
[0079] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0080] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
[0081] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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Methods to tag objects in a cloud computing environment, by tagging an object with a first tag, of a plurality of tags, wherein each of the plurality of tags specifies a respective criterion for objects tagged by each tag, and upon determining that the object not satisfy the criterion of the first tag, performing an action associated with the first tag to modify the object to meet the criterion of the first tag.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an insulation material comprising a basic material which is built up of cells and a filler which is present in said cells.
The invention furthermore relates to a method for producing such insulation material and to a device for carrying out the method in order to obtain the intended insulation material.
2. Discussion of the Background
From U.S. Pat. No. 4,271,876 it is known to use insulation material comprising a basic material built up of cells for producing prefabricated building components. The thermal and acoustic insulation value of such building components incorporating basic materials built up of cells can be further enhanced, however. The improvement of the thermal and acoustic insulation of such insulation material may take place by filling the cells with a filler of for example mineral wool fibres or cellulose fibres.
The term fibres used herein is understood to mean short, elongated particles, but also granular particles and the like.
Several experiments have been conducted within this framework, but it has become apparent that it is very difficult to fill the cells properly with such relatively light fibres. As a result of the problems involved in the filling of such basic material the use of this insulation material has not led to the expected large-scale use, because the increasingly stringent requirements with regard to the insulation value are not met.
SUMMARY OF THE INVENTION
The object of the invention is to provide an insulation material whereby fibres have been introduced into the cells of the basic material in a simple manner.
This objective is accomplished with the basic material according to the invention in that said filler is built up of separate fibres, which are bonded together by means of a foam-like bonding agent.
The foam will make the fibres heavier, as a result of which the fibres can be introduced into the cells of the basic material by the force of gravity. Fibres not bonded to bonding agent are relatively too light, and they exhibit a tendency to remain on top of the basic material.
A major advantage of the insulation material according to the invention is the fact that it has a high insulation value and that the filler can be introduced into the cells in a simple manner.
It has to be noted that from WO 93/25492 an isulation material is known comprising fibres which are bonded together by means of a foamlike bonding agent. However, this insulation material is used as such.
Another object of the invention is to provide a method wherein fibres can be introduced into the cells of the basic material in a simple manner.
This objective is accomplished with the method according to the invention in that first a mixture of separate fibres and a foam-like bonding agent is prepared, and that this mixture is introduced into the open cells of the basic material via a nozzle.
The fibres, which are weighted and bonded by the foam, can be introduced into the cells of the basic material in a simple manner, for example under the influence of the force of gravity.
One embodiment of the method according to the invention is characterized in that said filler is defibered into fibres, the fibres are subsequently bonded together by means of the bonding agent, after which the bonded fibres are defibered anew and introduced into the cells of the basic material.
By defibering the filler relatively small fibres or separate particles will be obtained. Said fibres are subsequently bonded to the bonding agent, as a result of which the specific weight of each fibre will increase. The fibres will also adhere together as a result of the presence of the bonding agent. When subsequently the fibres provided with the bonding agent are defibered, fibres weighted by the bonding agent will be obtained, which will fall into the cells of the basic material under the influence of the force of gravity. It is also possible, of course, to blow or suck the fibres into the cells of the basic material.
One embodiment of the method according to the invention is characterized in that upon providing the fibres with the bonding agent, the fibres are formed into a foam by means of the bonding agent, which foam is subsequently defibered.
Defibering the foam will result in the formation of separate fibres surrounded by bonding agent, which can be introduced into the cells of the basic material in a simple manner. The fibres will adhere together again once they are in the cell, to which adhering process the bonding agent will be conducive.
Another embodiment of the method according to the invention is characterized in that the basic material is vibrated while the fibres are being introduced into the cells.
The vibration of the basic material will cause the particles being introduced into the cells to move downward, thus creating space for additional fibres near the upper side of the cells. In this manner the cells will be entirely filled with fibres.
The invention also relates to a device suitable for carrying out the method, which comprises a filling station, which device is characterized in that said filling station is provided with a mixer for mixing said bonding agent and said fibres, so as to obtain said filler.
The fibres are bonded to the bonding agent by means of such a device before being introduced into the cells of the basic material.
One embodiment of the device according to the invention is characterized in that the device comprises a first defibering apparatus, a mixer connected to said first defibering apparatus via a pipe, which mixer is connected, via a further pipe, to a second defibering apparatus, which is provided with an outlet opening.
With such a device the first defibering apparatus is used for reducing the insulation material to fibres. The second defibering apparatus is used for separating the fibres, which adhere together as a result of the presence of the bonding agent.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail with reference to the drawing, in which:
FIG. 1 is a longitudinal sectional view of a device according to the invention; and
FIG. 2 shows another device according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a device 1 comprising a first defibering apparatus 2 , a mixer 4 , which is connected to defibering apparatus 2 via a flexible pipe 3 , a second defibering apparatus 6 , which is connected to mixer 4 via a flexible pipe 5 , and a conveyor 7 , which is disposed under defibering apparatus 6 .
Defibering apparatus 2 is provided with an inlet channel 8 , under which three rotatable rollers 9 , 10 , 11 fitted with wire brushes are disposed. Roller 9 abuts against roller 11 . A feeding gap 12 is present between rollers 9 , 10 . Roller 9 is driven in clockwise direction, as indicated by arrow P 1 , whilst rollers 10 , 11 are driven in anti-clockwise direction, as indicated by arrows P 2 , P 3 . The speeds at which rollers 9 , 11 are driven in the direction indicated by arrow P 1 , P 3 and the pressure with which roller 9 is driven against roller 11 can be adjusted and varied.
Defibering apparatus 2 is provided with a passage 13 under rollers 9 , 10 , 11 , which passage opens into a space 14 . Present in space 14 is a blade wheel 16 , which bears on a shaft 15 and by means of which fibres coming from passage 13 are transported. Disposed under space 14 is a dividing apparatus 17 , which is provided with a number of rods 18 coupled to a central shaft, which rods extend between fixedly disposed rods 20 . Disposed under apparatus 17 is a dividing station 19 . An air blowing unit 21 , which is driven by means of a motor, is connected to dividing station 19 via a pipe 20 . Dividing station 19 is connected to mixer 4 via flexible pipe 3 . Mixer 4 is furthermore provided with a supply pipe 22 for compressed air and with a supply pipe 23 for a bonding agent. Mixer 4 is connected to a second defibering apparatus 6 via a pipe 5 . Defibering apparatus 6 comprises a blade wheel 25 near an upper side, which is rotatable about a shaft 24 , and rollers 26 , 27 , 28 , which are disposed under blade wheel 25 . Rollers 26 , 28 , which are provided with wire brushes, abut against one another. A gap 29 is present between roller 26 and roller 27 . Rollers 26 , 28 , 28 are rotatable in directions indicated by arrows P 4 , P 5 and P 6 respectively. An outlet opening 30 , which opens above conveyor 7 , is present under rollers 26 , 27 , 28 . Conveyor 7 is provided with a conveyor belt 31 , a number of vibrating devices 32 disposed under conveyor belt 31 , and a number of brushes 33 , 34 , 35 , which are disposed an adjustable distance above conveyor belt 31 . Conveyor 7 is furthermore provided with a strickling brush 36 . Vibrating devices 32 are each provided with a vibrating plate 37 , which is reciprocated in the directions indicated by double arrows P 7 , P 8 by means of a drive unit 38 . Plate-shaped material 39 comprising a plurality of cells 40 is present on conveyor belt 31 . Cells 40 form a honeycomb structure in plate 39 . Brushes 33 , 34 are rotatable about an axis extending transversely to the plane of the drawing. Brush 35 is rotatable about an axis including an acute angle with the plane of the drawing.
The operation of device 1 will now be briefly explained. Relatively large pieces of filler, for example in the shape of plates or pieces, are supplied to defibering apparatus 2 in the direction indicated by arrow P 9 via inlet opening 8 . Said filler is pulled into gap 12 by rollers 9 , 10 , from where the filler is pulled between rollers 9 , 11 and transported in the direction of passage 13 . Rollers 9 , 11 are driven at different speeds, as a result of which the filler is pulled apart into fibres. Fibres 41 whirl into space 14 and are transported in the direction indicated by arrow P 10 by means of rotating blade wheel 16 . Then the fibres are grabbed by the rods 18 of device 17 , which rotate about the shaft, and carried into device 19 . The filler being introduced into inlet 8 is pulled completely apart by rollers 9 , 11 , blade wheel 16 and rotating rods 18 , and divided into relatively small fibres. Air blowing device 21 blows air into device 19 via pipe 20 , as a result of which the fibres present in the device 19 are carried into pipe 3 . The fibres are blown further apart by the air flow. The fibres are transported through pipe 3 in the direction indicated by arrow P 11 , to mixer 4 . Compressed air and a bonding agent are supplied to mixer 4 via pipe 22 and pipe 23 respectively, as a result of which the fibres present in mixer 4 are efficiently bonded to the bonding agent. The fibres, which are bonded to the bonding agent and which are provided with bonding agent are blown in the direction indicated by arrow P 12 into pipe 5 by the air flow produced by device 21 , from where the fibres provided with bonding agent, which adhere together by now, are carried into defibering apparatus 6 . The bonded-together fibres are pulled slightly apart by the blade wheel 25 rotating about shaft 24 . Then the fibres are passed in the gap 29 between rollers 26 , 27 in the direction indicated by arrow P 13 . Rollers 26 , 28 are driven at different, variable speeds, as a result of which the bonded-together fibres are pulled apart and carried in the direction indicated by arrow P 14 towards outlet 30 . Outlet 30 is located above the plate 39 comprising cells 40 , and the fibres provided with bonding agent, which have been separated from each other by defibering apparatus 6 , will fall into cells 40 under the influence of the force of gravity. Base plate 39 is vibrated to and fro by means of vibrating devices 32 disposed under conveyor belt 31 , as a result of which the fibres falling into cells 40 will move further in downward direction. The fibres falling onto plate 38 are swept into cells 40 by means of brush 36 , which is driven in the directions indicated by double arrow P 15 and in directions extending transversely thereto.
During the filling of cells 40 base plate 39 is slowly moved in the direction indicated by arrow P 16 by means of conveyor belt 31 . During said movement the fibres still present on plate 39 are swept into cells 40 by brushes 33 , 34 . Any fibres remaining on the plate are swept off said plate by brush 35 , which is disposed at an angle with respect to brushes 33 , 34 .
FIG. 2 diagrammatically shows another device for producing the insulation material according to the invention.
FIG. 2 shows filling station 41 comprising a mixing head 42 , in which the filler is mixed by supplying the mineral wool fibres or the cellulose fibres as well as the bonding agent. Following the mixing step the foam thus formed is introduced into cells 45 of honeycomb 44 via outlet 43 . Filling station 41 is furthermore provided with a strickle 46 , so that excess foam-like filler is removed and transferred to incompletely filled cells. The filled cells 47 contain a filler, which is dried, if necessary, so that the fibres are surrounded by cured foam, resulting in a cohesion between the individual fibres mutually and an adherence to the cell surfaces. Thus the cells are filled with an insulating filler.
In order to promote the evacuation of the air from the honeycomb structure 44 , an air exhaust channel 48 is provided at the bottom side, by means of which air is exhausted, without any filler being carried along. The honeycomb is passed under the filling station in the direction indicated by arrow 49 , whereby the combs are gradually filled with foam consisting of said material mixed with the separate particles, so that a honeycomb structure filled with a filler is formed, as a result of which the insulation value is enhanced in comparison with the honeycomb structure which is not filled with a filler.
Any material with which the individual fibres can easily be weighted may be used as the bonding agent. The fibres may first be moisturized and weighted by means of the bonding agent and subsequently be bonded together and dried in the cells.
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An insulation material and method for producing it. A basic material is built up of cells and a filler which is present in the cells. The filler is built up of separate fibers which are bonded together by means of a foam-like bonding agent. The filler is introduced into the open cells of the basic material. A mixture of separate fibers and a foam-like bonding agent is prepared and the mixture is introduced into the open cells by way of a nozzle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefits of priority under 35 U.S.C. §§119 and 120 to U.S. Provisional Application No. 61/565,953, filed on Dec. 1, 2011, the entirety of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure is directed towards laser ocular surgery, and more particularly, the use of a laser ocular surgery for treating glaucoma.
BACKGROUND
[0003] Glaucoma is caused by the body's inability to drain the clear, transparent liquid called the aqueous humor. Aqueous humor flows through the inner eye continuously. Typically, the aqueous fluid drains from the anterior chamber to the sclera, through a variety of drainage channels or canals. However, these channels can become smaller with age or become clogged by deposits. Inadequate drainage of the aqueous humor from the anterior chamber can lead to an abnormally high fluid pressure results within the eye. This is referred to as glaucoma. The high fluid pressure can lead to a slow loss of peripheral vision and eventually blindness.
[0004] Traditional glaucoma treatments can include forming a channel in the sclera of the eye to drain aqueous fluid from the anterior chamber of the eye, reducing fluid pressure. Typically, the channel in the sclera is made by a knife or other mechanical devices. These mechanical devices can cause trauma to the scleral tissue, resulting in scar tissue formation that can eventually obstruct the channel.
[0005] It is accordingly an object of the present disclosure to provide an improved system and method for reducing the high fluid pressure in the anterior chamber of the eye.
SUMMARY
[0006] In accordance with the present disclosure, one aspect of the present disclosure is directed to a method of laser ocular surgery for treating glaucoma. The method can include imaging a treatment eye to obtain an image of the treatment eye and aligning a laser on a region of the treatment eye based on the image of the treatment eye. The method can also include firing a plurality of laser pulses from the laser to ablate tissue in the region of the treatment site, wherein the tissue ablation creates micro-perforations in the region of the treatment site to incite an inflammatory reaction.
[0007] In another embodiment, a system can be configured for laser ocular surgery. The system can include an imaging device configured to image a portion of a treatment eye, and a laser configured to generate a beam having power sufficient to create micro-perforations in the portion of the treatment eye. The system can also include an interface device coupling the laser to the treatment eye, wherein the interface device is configured to adjust a path of the beam based on output from the imaging device
[0008] Additional objects and advantages of the present disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present disclosure. The objects and advantages of the present disclosure will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure, as claimed.
[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the present disclosure and together with the description, serve to explain the principles of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is schematic diagram of an ocular surgical system, according to an exemplary embodiment.
[0012] FIG. 2 is a flow diagram illustrating a method of ocular surgery, according to an exemplary embodiment.
[0013] FIG. 3 is a flow diagram illustrating a method of ocular surgery, according to another exemplary embodiment.
[0014] FIG. 4 is a diagram of a part of an eye.
[0015] Reference will now be made in detail to the present embodiments of the present disclosure, an examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
DETAILED DESCRIPTION
[0016] It is understood that the embodiments described herein are not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, embodiments, and substitution of equivalents that all fall with the scope of the present disclosure. Accordingly, the present disclosure is not limited by the foregoing or following descriptions.
[0017] FIG. 1 is a schematic diagram of a surgical system 110 for performing ocular surgery using a laser, according to an exemplary embodiment. Surgical system 110 can comprise a laser 120 , an interface device 130 , an imaging device 140 , and a controller 150 . Laser 120 can include a femtosecond laser. In some aspects, laser 120 can include a type of laser configured to create micro-perforations in a portion of a treatment eye. For example, laser 120 can have sufficient power to form a plurality of micro-perforations in a trabecular meshwork of a treatment eye. Laser 120 can be further configured to ablate part of the treatment eye. Such treatment can be used to provoke an immune response to aid remodeling of tissue associated with the treatment eye.
[0018] Interface device 130 can be configured to couple patient 160 to laser 120 . Device 130 can include attachments (not shown) configured to contact patient 160 to ensure laser 120 remains secure during a procedure. When coupled, interface device 130 can be positioned between laser 120 and a treatment eye 170 of patient 160 .
[0019] In some embodiments, interface device 130 can comprise a mirror, a reflective substrate, or equivalent substrate configured to optically direct the path of laser 120 towards the treatment site of treatment eye 170 . The treatment site can include the anterior segment of the eye, the trabecular meshwork, or the anterior sclera. Other regions of the eye may also be treated.
[0020] Imaging device 140 can comprise an optical coherence tomography (OCT) device, Schiemflug imaging device, or other equivalent imaging device capable of capturing images of ocular anatomy. Various other imaging devices may also be used. In addition, controller 150 can be part of imaging device 140 or can be a separate device. Controller 150 can be configured to receive data from imaging device 140 and output a signal to orient the mirror or reflective substrate of interface device 130 to direct laser 120 at the treatment site.
[0021] FIG. 4 shows a diagram of an eye 170 , which is used to describe the method according to an exemplary embodiment. The eye comprises a lens 410 , a pupil 420 , a cornea 430 , an iris 440 , a conjunctiva 450 , a sclera (anterior) 460 , an anterior chamber 470 , a travecular meshwork 480 , a Schwalbe's line 490 , a corneal limbus 500 , an anterior segment 510 , and a posterior segment 520 .
[0022] FIG. 2 shows a flow chart 200 , for a method of performing ocular surgery, according to an exemplary embodiment. The first step, S 210 , can comprise attaching interface device 130 as described in relation to FIG. 1 . Attaching interface device 130 can comprise aligning the interface device between laser 120 and treatment eye 170 . Interface device 130 can be configured to expose anterior segment 510 of treatment eye 170 when attached. After completing step S 210 , the next step S 220 , can comprises directing imaging device 140 at the treatment eye 170 .
[0023] Once Step S 220 is completed, step S 230 can comprise using imaging device 140 to detect and register the image and convert the image to a pixel coordinate plane by way of the imaging device software program. Following step S 230 , step S 240 can comprise the controller 150 using the pixel coordinate data to align the mirror or reflective substrate of interface device 140 towards the treatment site. Controller 150 can be integrated into imaging device 140 and can include processor, computer readable data, and software programming. The treatment site can include the trabecular meshwork and angle of anterior segment 510 of treatment eye 170 .
[0024] Next, step S 250 , can comprise laser 120 being energized and aimed at this tissue plane of the treatment site and the tissue can be ablated with various spot sizes of laser 120 , in a 180 or 360 degree fashion. In other example, arcs of less than 360 degrees may be created on or about a region of the treatment eye.
[0025] Following step S 250 , step S 260 can comprise creating micro-perforations of the travecular meshwork 480 . These can be used to incite a mild inflammatory reaction in order to recruit macrophages and trabecular meshwork cells to the treatment site in order to initiate tissue remodeling at the treatment site.
[0026] In another embodiment, a method similar to that described above in relation to FIG. 2 is shown in FIG. 3 as flow chart 300 . The method described in flow chart 300 uses an interface device 130 configured to extend beyond the corneal limbus 500 to allow laser 120 to target the anterior sclera 460 , adjacent to the Schwalbe's line 490 and the trabecular meshwork 480 of treatment eye 170 . In alternative embodiments (not shown), a different device than interface device 130 can be used to target laser 120 to the treatment site.
[0027] The method of flow chart 300 can begin with Step S 310 , which comprises attaching a larger interface device that allows extending beyond the corneal limbus, as described above. Steps S 320 , S 330 , S 340 , and S 350 can each be similar to corresponding steps S 220 , S 230 , S 240 , and S 250 described above in relation to FIG. 2 . Step S 360 , however, can be different than previously described step S 260 . Step S 360 can comprise creating micro-perforations through anterior sclera 460 . These micro-perforations can form a type of micro-drainage channel that may allow aqueous fluid to exit anterior chamber 470 of the treatment eye 170 . The fluid could flow into a subconjunctival space between the subconjuctiva 450 and sclera (anterior) 460 .
[0028] In another embodiment, S 360 can comprise creating micro-channel perforations, which may allow aqueous fluid to escape the anterior chamber via the uveo-scleral outflow pathway.
[0029] In another embodiment, S 360 can comprise creating micro-channel perforations using laser 120 in conjunction with a subconjunctival injection/delivery system (not shown). Such a delivery system can be configured to introduce a micro-stent through the conjunctiva and into the micro-channel to the anterior chamber created by laser 120 . Micro-stents of various shapes and sizes could be configured for specific use with a portion of the treatment eye. Various other devices and systems may also be required to ensure proper delivery of the micro-stents relative to the micro-channels in the treatment eye.
[0030] Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the present disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the present disclosure being indicated by the following claims.
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A method of laser ocular surgery for treating glaucoma is disclosed. The method can include imaging a treatment eye to obtain an image of the treatment eye and aligning a laser on a region of the treatment eye based on the image of the treatment eye. The method can also include firing a plurality of laser pulses from the laser to ablate tissue in the region of the treatment site, wherein the tissue ablation creates micro-perforations in the region of the treatment site to incite an inflammatory reaction.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a structure of a carbon molecular beam source provided in a molecular beam epitaxial growth apparatus and particularly to a structure of graphite filament which operates as a carbon molecular beam source.
As a p-type dopant for III-V compound semiconductor, beryllium (Be) has been generally used. However, in these years, a p-type base of a heterojunction bipolar transistor (HBT) which has been produced by the molecular beam epitaxy (MBE) method as a high speed device provides a problem that a concentration profile is disturbed remarkably in the base layer due to diffusion of Be because a base layer is thin and concentration of Be is high. Therefore, carbon (C) which is more difficult to result in diffusion than Be is attracting more attention as the p-type dopant.
Carbon vapor is usually generated by heating graphite resistively with a current. In this case, it is extensively required that an amplitude of the heating current is in the practical range and carbon beam intensity is stabilized from the point of view of manufacturing a device.
2. Description of the Related Art
In order to generate carbon beam in a molecular beam epitaxial growth method, carbon vapor is usually generated by resistively heating of a graphite filament provided in a doping cell of a molecular beam epitaxial growth apparatus (hereinafter, called a MBE growth apparatus). FIG. 1 is a perspective view of a conventional graphite filament which operates as a carbon molecular beam source.
As shown in FIG. 1, a filament 10 comprises a heating portion 6 and current terminals 3 provided at both ends thereof. A material used is a sintered graphite or pyrolytic graphite. The heating portion 6 is sized, for example, as 1 mm in thickness, 2 mm in width and 50 mm in length.
When sintered graphite is selected as the material, the filament 10 is cut in the direction selected freely from a block of the sintered graphite. Meanwhile, when pyrolytic graphite is selected, a generally available material is thinner in the direction of c-axis and is formed as a plate spreading in the plane perpendicular to the c-axis. Therefore, the filament 10 has a structure allowing power feeding in the plane perpendicular to the c-axis. Intensity of carbon molecular beam can be controlled by controlling a current fed to the filament 10.
However, since resistivity of sintered graphite is not anisotropic and is about 10 -2 ohm·mm, while resistivity of pyrolytic graphite in the direction perpendicular to the c-axis is about 4×10 -3 ohm·mm, a heating current of the filament 10 has a considerably large value. This is a first problem. That is, graphite must be set to a temperature of about 2000° C. in order to generate carbon molecular beam by heating graphite with a current. For this purpose, the filament consumes the power of about 300 W/cm 2 . In the case of sintered graphite, when the heating portion 6 of the filament 10 is sized as 1 mm in thickness, 2 mm in width and 50 mm in length (current direction), the filament 10 shows resistance of 0.25 Ω and current of 35 A. On the other hand, when the same filament 10 is formed of pyrolytic graphite, a current is fed in the direction perpendicular to the c-axis, resistance becomes 0.1 Ω and current is about 55 A. The filament 10 explained above is used for a carbon molecular beam source cell of a small size MBE growth apparatus which the distance between the growth substrate and the carbon molecular beam source cell is about 20 cm. If this filament 10 is used for carbon molecular beam source of a large size MBE growth apparatus resulting in the distance of about 60 cm, the carbon molecular beam intensity which is about one order of magnitude larger than that used for the small size apparatus is required. In this case, consumption of the filament 10 due to evaporation of carbon also becomes about ten times larger and therefore thickness of the filament must be ten times thicker than that for a small size MBE growth apparatus if the filament area is constant. When the heating portion 6 is formed of the pyrolytic graphite sized as 10 mm in thickness, 2 mm in width and 50 mm in length, a current becomes 173 A and this value is practically too large.
Of course, it is possible to provide a filament having the area increased by 10 times, but power consumption is also increased up to 10 times in this case. From this point of view, it is not a practical method.
The second problem of a conventional graphite filament is that if filament resistance changes, intensity of molecular beam also changes because intensity of carbon molecular beam is controlled by a filament current. That is, a resistance value of the filament 10 changes with evaporation of carbon. Accordingly, if a current is controlled to a constant value, power consumption of the filament 10 changes and temperature of the filament 10 also changes. As a result, intensity of carbon molecular beam changes. For instance, under the ordinary application condition, the filament 10 mentioned above (the heating portion 6 has the sizes of 1 mm in thickness, 2 mm in width and 50 mm in length) shows reduction of thickness at a rate of about 1 μm/h. Therefore, resistance increases at a rate of about 0.1%/h, while power consumption also increases. Temperature of the filament rises to 2000.57° C. from 2000° C., while carbon vapor pressure is almost proportional to 10 -40000 /T (T is the absolute temperature of the filament). Thereby, intensity of carbon molecular beam increases at a rate of about 1%/h.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a kind of graphite filament for carbon molecular beam having a high resistance value which enables heating with a sufficiently practical current value.
It is another object of the present invention to provide a kind of graphite filament which stably supplies carbon molecular beam even if a resistance value of graphite filament changes due to evaporation.
The objects mentioned above are all achieved by carbon molecular beam source having a heating portion which permits power feeding in the direction of c-axis of graphite.
FIGS. 2A, 2B, 2C, 2D are diagrams for explaining the principle of the present invention. As shown in FIG. 2A, the graphite filament 10 of the present invention has the heating portion 1 in which a current flows in the direction of c-axis of graphite and a wiring portion 2 in which a current flows in the direction perpendicular to the c-axis of graphite. The current enters one heating portion 1 from one current terminal 3, then enters the other heating portion 1 through a wiring portion 2 connected to the heating portion 1 and then goes out of the other current terminal 3 connected to the other heating portion 1. A resistivity of pyrolytic graphite in the direction perpendicular to the c-axis is about 4×10 -3 Ω·mm but resistivity in the direction of the c-axis is about 2Ω·mm. Therefore, a resistance of the filament 10 as a whole can be set to several Ω. In the case of the graphite filament 10 of the present invention, carbon e evaporates from both heating portion 1 and wiring portion 2. However, since resistance of the wiring portion 2 is small in comparison with that of the filament 10 as a whole, consumption of the wiring portion 2 due to evaporation gives only a small influence on resistance of the filament 10. Accordingly, change of carbon molecular beam intensity can be reduced by increasing a rate of carbon molecular beam emitted from the wiring portion 2.
For accurate control of carbon molecular beam intensity, it is effective to measure and control power consumption of filament with high precision. In view of enhancing measuring accuracy of power consumption of the filament, a branch terminal 4 is respectively provided to a couple of current terminals 3 as shown in FIG. 2B and a voltmeter 9 is connected to the branch terminal for measuring a voltage thereof. Thereby, an accurate filament voltage can be measured by eliminating influence of contact resistance and wiring resistance. The power supply 7 is controlled so that power consumption of the filament becomes constant, by observing indication of an ammeter connected in series to the power supply 7 connected to the current terminal 3 and indication of a voltmeter 9. Carbon molecular beam intensity can be accurately controlled with such a method.
Moreover, as another method for accurately controlling carbon molecular beam intensity, it is an effective method to accurately measure the temperature of filament and then control the power supply 7 with such temperature. An area where is comparatively low in temperature and is a little changed in the shape due to evaporation is formed in anywhere on the filament. A resistance value of this area can be thought as depending only on temperature since there is no change of resistance value due to the change of shape. Therefore, temperature of the filament can be detected from dependence of resistivity on temperature by measuring a resistance value. As shown in FIG. 2C, a resistance measuring portion may be selected only to the wiring portion 2. However, it is also possible to include the heating portion 5 as shown in FIG. 2D in order to increase measuring accuracy by increasing a resistance value. The filament shown in FIG. 2D has the constitution combining FIG. 2A and FIG. 2B. When the resistance measuring portion includes the heating portion 5, a resistance value is set smaller than that of the other heating portion 1 in order to make small the change due to evaporation.
As described, using a graphite filament of the present invention for the MBE growth as a carbon molecular beam source, a large intensity carbon molecular beam can be generated by feeding a current having the sufficiently practical amplitude as high as about 30 A. Moreover, fluctuation of carbon molecular beam intensity is 0.3% or less per hour and this value is about 1/3 that in the prior art where a current is controlled to the constant value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating a graphite filament of the prior art;
FIGS. 2A-2D are diagrams for explaining the principle of the present invention;
FIG. 3A is a plan view of a pyrolytic graphite filament of the type providing branch terminals respectively to a couple of current terminals;
FIG. 3B is an A-B-C-D-E-F schematic sectional view of the pyrolytic graphite filament of FIG. 3A.
FIG. 4A is a plan view of a pyrolytic graphite filament of the type providing two kinds of heating portions having different resistance values;
FIG. 4B is a G-C-D-H schematic sectional view of FIG. 4A;
FIG. 4C is an A-B-C-D-E-F schematic sectional view of FIG. 4A;
FIG. 5 is a table showing data when a graphite filament in the first and second embodiments is applied to an MBE growth apparatus;
FIG. 6 is a schematic diagram of a large size MBE growth apparatus loading a graphite filament of the present invention;
FIG. 7A is a schematic plan view of a graphite filament loaded in a carbon molecular beam source cell;
FIG. 7B is a schematic front elevation of a graphite filament loaded in a carbon molecular beam source cell;
FIG. 8 is a diagram illustrating a GaAs molecular beam epitaxial layer obtained by conducting carbon doping using the graphite filament of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Two embodiments of the present invention will then be explained by referring to the accompanying drawings. The like elements and the materials are designated by the like reference numerals throughout the drawings.
First Embodiment
This embodiment is basically a pyrolytic graphite filament of the type respectively providing branch terminals 4 to a couple of current terminals as shown in FIG. 2B. A plan view of this filament is schematically shown in FIG. 3A. As shown in FIG. 3A, the current terminal 3 is connected in series with a power supply 7 and an ammeter 8. The branch terminal 4 is connected with a voltmeter 9. FIG. 3B shows an A-B-C-D-E-F sectional view of the graphite filament of FIG. 3A. As illustrated in the figure, this graphite filament integrally comprises six heating portions 1 and seven wiring portions 2 connecting the heating portions 1. Practically, these portions of a graphite filament are formed by making the predetermined grooves on the obverse and reverse face of a graphite plate, of which direction coincides with the c-axis of the graphite plate. The heating portion 1 is shaped as a rectangular column extending in the direction matched with the c-axis of the pyrolytic graphite. The heating portion 1 is connected with the wiring portions 2 at a couple of end faces perpendicular to the c-axis. The end face has the dimension of 6 mm×6 mm and the length thereof in the direction of the c-axis is about 3 mm. The pyrolytic graphite used are all made by Union Carbide Corp.
The power supply 7 is controlled so that the power is kept constant by consulting with indication of the ammeter 8 and voltmeter 9. As an example of the control system, following system is used. That is, outputs of the ammeter 8 and voltmeter 9 are input to a multiplier (not illustrated) for computing the power and then an output of the multiplier is input to PID (proportional plus integral plus derivative) controller (not illustrated). An output of the PID controller is used as a control input of the power supply 7.
A graphite filament similar to that shown in FIG. 3A, however, connecting in series 15 heating portions 1 has been used in a large size MBE growth apparatus keeping the distance between the carbon molecular beam source cell and the growth substrate as long as about 60 cm. This large size MBE growth apparatus loading such graphite filament is schematically shown in FIG. 6. FIG. 6 schematically illustrates a structure of the cross-section of the growth chamber 16 of the MBE growth apparatus. In the growth chamber 16, the molecular beam source cell 23 for MBE growth (generally composed of a plurality of cells, but represented here by only one cell), the carbon molecular beam source cell 17 of the present invention and the growth substrate 20 are arranged via the molecular beam source cell shutter 22. Moreover, in the growth chamber 16, a growth chamber shroud 19 for maintaining high vacuum condition of the growth chamber and a molecular beam source cell shroud 18 for preventing mutual thermal interference of molecular beam source cell are provided.
The carbon molecular beam source cell 17 comprises therein the graphite filament is fixed to a flange 21 of the growth chamber 16 with a flange 15.
FIG. 7A and FIG. 7B schematically illustrate the graphite filament 10 loaded in the carbon molecular beam source cell 17. As shown in FIG. 7A, FIG. 7B, the graphite filament 10 is arranged at the inside of a cylindrical reflector 11 and leads 12 from the current terminal 3 and branch terminal 4 of the graphite filament 10 are respectively guided from a vacuum flange 15 through electric feedthroughs 13. A thermocouple 14 for roughly monitoring temperature of the graphite filament 10 is provided in the vicinity of the filament 10 and the leads thereof are also guided from the vacuum flange 15, which is coupled with a flange 21 shown in FIG. 6.
Carbon has been experimentally doped with the carbon molecular beam during actual epitaxial growth of gallium arsenide (GaAs) using MBE growth apparatus shown in FIG. 6. As shown in FIG. 8, an undopod GaAs epitaxial layer 25 has been grown in the thickness of 500 nm on a semi-insulating GaAs substrate 24, and a carboll doped GaAs epitaxial layer 26 has successively been grown thereon in the thickness of 200 nm. In this case, a current of graphite filament 10 is about 30 A and carbon molecular beam intensity has been 5×10 19 m -2 h -1 on the substrate. That is, carbon concentration in the GaAs epitaxial layer 26 is 5×10 19 cm -3 when the growth rate of the epitaxial is 1 μm h -1 . In addition, fluctuation of the carbon molecular beam intensity has been 0.3%/h or less which is about 1/3 that when a current is controlled to a constant value.
Though a carbon doped GaAs MBE layer is explained as an example in this embodiment, carbon doped MBE layer of another III-V compound semiconductor can be obtained by using the present carbon molecular beam source.
Second Embodiment
This embodiment is basically a pyrolytic graphite filament of the type providing two kinds of heating portions having different resistance values as shown in FIG. 2D. A plan view of this embodiment is schematically shown in FIG. 4A. A G-C-D-H sectional view of FIG. 4A is schematically shown in FIG. 4B. Moreover, an A-B-C-D-E-F sectional view of FIG. 4A is schematically shown in FIG. 4C.
As shown in FIG. 4C, the graphite filament of this embodiment integrally includes two heating portions 5 having small resistance value and tour heating portions 1 having large resistance value. Two heating portions 5 are arranged at the center, while two heating portions 1 are respectively arranged at the one end portion of the filament, that is, four heating portions 1 in total at both ends thereof. As shown in FIG. 4A, the current terminal 3 is connected in series with the power source 7 and ammeter 8. The wiring portion 2 connected with the heating portion 5 is provided with a branch terminal 4 which is connected with a voltmeter 9.
The heating portion 5 and heating portion 1 are both formed in the rectangular column shape of which column direction is matched with the c-axis of the pyrolytic graphite filament. The heating portions 5 and 1 have the end faces in size of 12 mm×6 mm and 6 mm×6 mm, respectively, and length in the c-axis direction of about 3 mm. The end faces of the heating portions 5 and 1 are connected with the wiring portion 2.
The power supply 7 is controlled so that a resistance value obtained from indications of ammeter 8 and voltmeter 9 is kept constant. As an example, following control system is used. Namely, outputs of the voltmeter and ammeter are input to a divider (not illustrated) to compute an reciprocal number of a resistance value and an output of the divider is then input to a PID controller (not illustrated). An output of the PID controller is used as a control input of the power supply.
A graphite filament, similar to that shown in FIG. 4A, however, connecting 15 heating portions 1 and two heating portions 5 in series, has been used for the MBE growth apparatus of FIG. 6. Like the first embodiment, epitaxial growth of gallium arsenide (GaAs) is actually attempted using the MBE growth apparatus of FIG. 6. In this case, a current of graphite filament 10 is about 30 A and intensity of carbon molecular beam on the substrate is 5×10 19 m -2 h -1 . Moreover, fluctuation of carbon molecular beam intensity is 0.2%/h or less.
Data applied when the graphite filaments of the first and second embodiments are used in the MBE growth apparatus are shown in FIG. 5. In this case, a doping rate of about 5×10 19 m -2 h -1 is assumed. For comparison, data applied to the prior art are also indicated in the same figure.
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A graphite filament for generating carbon molecular beam which is heated through application of a current thereto integrally comprises a plurality of portions of which current directions match the c-axis of the graphite and a plurality of portions of which current directions are perpendicular to the c-axis.
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BACKGROUND
[0001] Some sliding doors are designed, when closed, to recess completely into a frame that is installed within a wall between two opposing wall surfaces. Such doors are commonly referred to as “pocket” doors. Pocket doors provide the functionality of a hinge-mounted door with the additional advantage of space-savings. They have become increasingly popular, for example in small homes and in offices where square-footage is expensive.
[0002] Referring to FIG. 1 , a pocket door 5 is shown with an example of prior art hardware 20 that allows the user to manipulate the door, e.g. open, close, lock and unlock. Pocket doors 5 feature two broad surfaces 10 and an end surface 12 . When the pocket door is in the open position, it is typically fully recessed in a frame contained in a wall (not shown). Pocket door hardware 20 can have a recessed area 30 . The recessed area 30 allows easier manipulation of the door 5 , e.g. as when opening or closing the door. Some versions of the hardware 20 feature a locking mechanism 35 . Mounting screws 40 secure the door hardware 20 to the door 5 .
[0003] Doors with this type of hardware may in some cases be difficult to open from a fully closed, recessed position, particularly if the user's hands are full or the user has difficulty grasping objects.
SUMMARY
[0004] Generally, the present disclosure relates to pocket door pull devices and methods of using such devices. These devices allow adaptation of existing pocket door hardware to provide exposed gripping surfaces to assist a user with opening the door when the pocket door is in a closed position and closing it when in an open position. In preferred implementations the devices can be installed using basic tools (e.g., a screwdriver) without the need for significant (or in most cases, any) modification of the door or existing hardware.
[0005] In one aspect, the invention features a device comprising a plate configured to fit over a surface pull of a pocket door, and members protruding from the plate away from the broad plane of the door.
[0006] Some implementations can include one or more of the following features.
[0007] The device may have an opening, which in some cases is dimensioned to allow access to an underlying recessed area. Furthermore, the opening may be dimensioned to allow use of a locking mechanism.
[0008] In some cases, the members may be generally perpendicular to the plate, and thus to the broad surface of the door when the device is in use. The members preferably have sufficient surface area to allow a user to apply a force to open or close the door. In some implementations, the members protrude from the surface of the door at least 0.2 inch (5 mm). The members may be positioned on opposite edges of the plate. The members may be configured such that, when the device is in use, at least one of the members extends generally parallel to the long axis of the door.
[0009] The plate may in some cases include mounting holes which are configured so that, when the plate is positioned over the surface pull, the mounting holes align with corresponding mounting holes of the surface pull. In some cases, the mounting holes may be elongated.
[0010] In another aspect, the invention features a device comprising pocket door hardware having a body, and a pair of members protruding from the body, such that when the pocket door hardware is mounted on a door the members extend away from a broad surface of the door.
[0011] Implementations of this aspect of the invention may in some cases include any one or more of the features discussed above.
[0012] The invention also features a method of opening a pocket door by applying a force to a member extending away from the broad plane of the door, wherein the member protrudes from a plate that is attached to the pocket door over a surface pull.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of prior art pocket door hardware.
[0014] FIG. 2 is a perspective view of a pocket door pull device according to one embodiment of the invention installed on a door, over the hardware shown in FIG. 1 (which is shown in phantom lines in FIG. 2 ).
[0015] FIG. 3 is a perspective view of the device.
[0016] FIG. 4 is a front planar view of the device.
[0017] FIG. 5 is an end view of the device.
[0018] FIG. 6 is a side view of the device.
DETAILED DESCRIPTION
[0019] The present disclosure relates generally to door pull devices for pocket doors that are configured to allow a user to more easily open the door from a closed position or close the door when it is in a open position. The devices prevent the door from closing fully, while also providing an exposed gripping surface, or handle, that the user can easily grasp. Preferred devices can be used with existing door hardware without modification or carpentry of the door or existing door hardware.
[0020] Referring to FIG. 2 , a pocket door pull device 22 is shown installed over the existing door hardware shown in FIG. 1 , utilizing the existing mounting holes 40 .
[0021] Referring to FIGS. 3 and 4 , the device 22 features a body 42 and two members 45 A/ 45 B extending outwardly on opposing sides of the body 42 . In use, the member 45 A, which is spaced from the edge of the door engages the door frame and prevents the door from being completely recessed in the wall. The member 45 B, the edge of which is preferably substantially aligned with the edge of the door, provides an exposed gripping surface or handle that can be grasped by the user to open the door. Referring to FIGS. 5 and 6 , the members 45 A/ 45 B are substantially perpendicular to the body 42 of the device to provide a good angle of contact with the user's fingers. In the embodiment shown, the members extend the full length of the device. Referring to FIG. 3 , edges 46 of members 45 A/ 45 B are radiused to prevent unwanted snagging or damage.
[0022] Ideally, a device 22 will be installed on each side of the door 5 , on surfaces 10 . This configuration allows the user to easily engage members 45 B from either side. The handles allow the user to more easily interact with the door in either the opening or closing directions.
[0023] Referring again to FIGS. 3 and 4 , two mounting holes 41 are positioned substantially near the middle of the device with respect to the long axis. Placement of the mounting holes 41 allows the user to utilize the mounting holes in the hardware 40 . Thus, it is not necessary for the user to drill additional holes when installing the device 22 , and the device can easily be mounted over the existing hardware, allowing continued use of the existing hardware. The mounting holes 41 are enlarged laterally to allow for accommodation of varying placement of hardware mounting holes ( FIG. 1 ).
[0024] In preferred embodiments the body 42 defines a central cut-out section 50 that approximately aligns with the central recessed portion 30 of the existing door hardware. The central cut-out 50 allows the user to access locking mechanisms 35 commonly found on pocket door hardware, e.g. as shown in FIG. 1 . The inner edges 43 ( FIGS. 3 and 4 ) of the body defined by the cut-out 50 are radiused to allow for better alignment with the central recessed portion 30 .
[0025] Referring to FIGS. 4-6 , in some implementations the device 5 is about 2 to 3 inches wide (W) and about 2 to 4 inches in length (HB). The members 45 A and 45 B protrude from the device 22 a distance sufficient to allow the member 45 A to act as a stop, and the member 45 B to be easily grasped, for example, at least 0.2 inches (5 mm), e.g., from about 0.2 to 1.0 inches (HM). For aesthetic reasons and ease of manufacturing and installation, the members are generally the same height. The device 22 is of a sufficient thickness to have a desired degree of stiffness. The wall thickness (T) of the device will depend on the physical characteristics of the material used, but is generally from about 0.01 to 0.10 inches. The cut-out 50 is dimensioned to expose the underlying latch mechanism, and may in some cases be about 1 to 1.5 inches wide (CW) and about 2 to 3 inches high (CH). The mounting holes 41 may in some cases be located at the mid point of the long axis of the device, i.e., midway between the top and bottom edges of the device (HH). The center of the mounting holes 41 can be, for example, from about 1.5 to 2 inches apart (HW).
[0026] Preferably, the device is made from a metal or a metal alloy, e.g. brass or steel, and is sufficiently strong to resist deformation when under load as when a door is opened or closed. Other materials may be suitable as well, for example, thermoplastics, thermosets, wood or ceramics. In some cases, the material may be transparent or translucent, for example LEXAN® plastic or LUCITE® plastic.
[0027] The device may be colored, or may be paintable so that the user can customize the appearance of the device.
OTHER EMBODIMENTS
[0028] A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure.
[0029] For example, rather than extending from a body that is configured to be mounted over existing pocket door hardware, the members could be integral with the pocket door hardware having a latching mechanism (e.g., extend integrally from the side edges of hardware otherwise resembling that shown in FIG. 1 ).
[0030] Another embodiment may feature the device installed in alternate locations on the door. For example, while it is generally preferred that the device be installed over the existing hardware, the device may be installed in a higher or lower location on the door, e.g., to facilitate use by users of different heights or a user in a wheelchair.
[0031] In FIG. 2 , the device is depicted as being installed on both sides of the door; however, the user could optionally install the device on only one side.
[0032] While it is generally preferred that members 45 A and 45 B protrude the same distance from the body, they could have different heights if desired. For example, member 45 A could be shorter (only high enough to act as a stop).
[0033] Either or both of the members could be disposed at an angle other than 90 degrees with respect to the body. For example, member 45 A could be generally perpendicular to the body while member 45 B could be at an acute angle with respect to the body.
[0034] Moreover, either of both of the members could be curved in cross-section, rather than extending straight out from the body.
[0035] While preferred embodiments feature a central cut-out section, an alternate embodiment could be configured without a central cut-out section or with a cut-out that is offset from center.
[0036] While the device 22 is preferably made of one continuous piece, an alternate embodiment could be constructed from multiple pieces.
[0037] An alternate embodiment could feature members that do not extend the full length of the device.
[0038] Another embodiment could feature members that are textured to enhance the user interface by increasing friction between the member and the user's finger. This could be accomplished by embossing, engraving, or other means.
[0039] While the device as shown features solid members, an alternative embodiment could feature members that are skeletal with portions removed.
[0040] The device can be provided in any desired style, e.g., including various ornamental features. As an example, the members could be scroll-shaped rather than simple vertical members, and/or the plate could have any desired shape.
[0041] Accordingly, other embodiments are within the scope of the following claims.
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The invention relates to pocket door hardware. Devices are disclosed that include a plate configured to fit over a surface pull of a pocket door, and members protruding from the plate away from the broad plane of the door.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefits of U.S. Provisional Application No. 60/787,870, filed Mar. 31, 2006, the disclosure of which is hereby incorporated by reference in its entirety including all figures, tables and drawings.
BACKGROUND OF THE INVENTION
[0002] Motor graders are used to maintain gravel roads in rural counties throughout the United States. In the spring and early summer however road shoulder maintenance becomes difficult with the rapid weed and grass growth. The weed and grass material if not properly processed provides poor material to spread on the road. Attachments for motor graders have been described (U.S. Pat. Nos. 2,036,598; 2,188,435; 5,108,221; 5,197,820; 5,810,097; 6,293,354 B1; 6,394,696 B1; and RE 34,860). These attachments however do not meet the current need. A need therefore remains for an attachment for a motor grader that chops vegetative material preparing it for the road surface.
[0003] All patents, patent applications, provisional patent applications and publications referred to or cited herein, are incorporated by reference in their entirety to the extent they are not inconsistent with the teachings of the specification.
SUMMARY OF THE INVENTION
[0004] The attachment of the subject invention comprises an offset disk connected to a motor grader via a mounting means. The mounting means attaches the disk to the ripper of the motor grader requiring no modification of the grader. An extra valve with a float control on the grader runs the hydraulics of the attachment. The attachment is deployed to the left side of the motor grader to disk the grass and gravel windrow as it comes off the grader's mold board. The attachment folds in along side of the motor grader when it is not being used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of a preferred embodiment of the attachment of the subject invention.
[0006] FIG. 2 is top plan view of a preferred embodiment of the attachment of the subject invention.
[0007] FIG. 3 is a side elevational view of a preferred embodiment of the attachment of the subject invention.
[0008] FIG. 4 is a rear end view of a preferred embodiment of the attachment of the subject invention.
[0009] FIG. 5 is an end view of the preferred embodiment of the attachment of the subject invention shown in FIG. 4 in motion.
[0010] FIG. 6 is a side elevational view of a preferred embodiment of the mounting means that connect the subject attachment to the ripper bar.
[0011] FIG. 7 is a side elevational view of a preferred embodiment of the attachment of the subject invention when not in use folded off the road surface.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The attachment of the subject invention comprises a small offset disk unit and a mounting system that connects the attachment to the ripper of a motor grader. The attachment is mounted on the left side of the motor grader and processes material from the mold board that gathers in windrows along the road so that it can be spread on the road surface. The mounting means folds the attachment off the road surface when the attachment is not in use.
[0013] A preferred embodiment of the attachment of the subject invention is shown in the appended figures ( FIGS. 1-7 ). An offset disk unit is hingedly connected to a motor grader ripper bar by a mounting means. The offset disk unit comprises two gangs of disks 10 , 12 positioned at approximately a 45° angle along a framework 14 ( FIG. 2 ). The disks are positioned so that the front gang of disk blades 10 move graded material one way and the rear gang of disk blades 12 move the graded material in the opposite direction. In a preferred embodiment, the front gang has 6-24″ disk blades and the rear gang has 7-24″ disk blades. The disk gangs in this embodiment have 10″ spools and cast housing sealed bearings. The shaft holding the disk blades and spools together depends on the center hole of the disk blades and the inside diameter of sealed bearings, 1½″ to 2″ is recommended. Positioning beams 16 , 18 of the framework 14 hold the front and rear gangs together, the narrowest part of gangs should preferably be no less than 2 feet apart. In the exemplified embodiment, disk size and spacing were chosen to suit road conditions in eastern Montana. The disks and framework of the subject attachment can become fouled with road material and vegetation. One skilled in the art would be able to determine proper disk size and separation for a particular road condition. Additionally, frame ends should be closed or capped to prevent debris from sticking in the framework.
[0014] The offset disk unit is mounted so it can float freely along the road's surface. The exemplified embodiment shows a simple system to allow the offset disk unit to oscillate ( FIG. 5 ). A tube 22 affixed to the bottom of positioning beams 16 and 18 of framework 14 receives the base of T-shaped member 20 . The tube 22 is supported by an underlaying brace ( FIG. 4 ). The T-shaped member 20 moves within the tube 22 allowing the disk unit to float over the road surface.
[0015] A mounting means attaches the offset disk unit to the ripper of a motor grader. In the exemplified embodiment, a T-shaped member 24 mounts the disk unit to the ripper bar. The base of braced T-shaped member 24 has shanks 26 which are inserted and secured in holes in the bar of the ripper 27 . Preferably, two shanks of the attachment are placed in the outermost and center holes of the bar. Ripper tines can therefore be placed in unused holes on the bar when the attachment is installed on the motor grader.
[0016] The offset disk unit is preferably hingedly attached to the ripper bar so that the disk unit can be lifted of the road surface when not in use ( FIG. 7 ). In a particularly preferred embodiment, the hinge is created by ears on the offset disk unit and the ripper mounting means pinned together ( FIG. 2 ). Ears 28 on the end of T-shaped member 20 engage ears 30 on the end of T-shaped member 24 . Pins 32 are threaded through apertures in the ears to create the hinge. The exemplified hinge member is preferred because it was less likely to foul under condition in eastern Montana. One skilled in the art would realize however that other hinge mens could be used on the subject attachment. For example, hinges created from bands and sleeves were found to foul in eastern Montana but may be suitable for areas with different vegetation, soil and road materials.
[0017] To use the attachment of the subject invention, the ripper is lowered to about 2 feet off the ground. A cylinder 34 is used to keep the disk horizontal with the top of road. If the top of road is hard, then the disk cylinder can be run in a float position. The disk cylinder is powered by an extra hydraulic valve on the motor grader that has a float position. Run the blade along the right side of road. As the material slides off the mold board it passes by the left side of motor grader where the disk unit of the subject attachment processes the bladed road material into a windrow. Then, driving in the opposite direction, run the blade along the other side of road. Combine both processed windrows to the left side of machine where the material will be processed again by the disk. The processed material can be spread over the top of the road or the operator can determine if more material processing is necessary.
[0018] It is understood that the foregoing examples are merely illustrative of the present invention. Certain modifications of the articles and/or methods may be made and still achieve the objectives of the invention. Such modifications are contemplated as within the scope of the claimed invention.
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An attachment for a motor grader mounts to the grader's ripper bar and uses the grader's auxiliary hydraulics. The attachment has an offset disk unit that is used to manage weed and grass growth in maintaining a roadway. The disk head is deployed on one side of the grader and folds into the grader when not in use.
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BACKGROUND OF INVENTION
1. Field of the Invention
This invention relates generally to testing of capacitor structures and, more particularly, to the testing of capacitor structures for electron tunneling. In even more particular aspects, this invention relates to testing of the dielectric material in capacitor structures for variations in electron tunneling at various locations in the dielectric material.
2. Background Information
In capacitor structures wherein a film of dielectric material is disposed between two plates of conductive material, electron tunneling occurs above some voltage differential between the plates, less than breakdown voltage. The voltage at which tunneling starts to occur (sometimes referred to as the tunneling voltage) is dependent upon the characteristics of the dielectric material. In an ideal situation, the dielectric would be entirely uniform in all regions, and thus electron tunneling would occur uniformly at the same voltage at all regions of the capacitor structure for the same thickness of dielectric material. However, such uniformity cannot be achieved in production, so tunneling can, and often does, occur at different voltages at different regions of the capacitor structure. This difference is especially important in low voltage (e.g. about 2 volts) thin film capacitors of the type used in microelectronics, such as integrated circuit (I/C) devices.
Present conventional test methods for testing thin film capacitors test only the entire capacitor structure, not any particular region. This will give an average value of the electron tunneling voltage across the entire structure, but it does not show any variations in tunneling voltage from region to region. However, a technique is desired to check for variations in voltage required for electron tunneling at various regions of the capacitor structure.
SUMMARY OF INVENTION
A method of determining electron tunneling values at various locations in a capacitor structure having a first and a second conductive plate with a dielectric material disposed there between, wherein each plate has first and second ends comprising the steps of; determining the nominal tunneling voltage of the dielectric material at its thickness to provide a target voltage.
Applying a first voltage level equally across the first plate. Applying a second voltage level to the first end of the second plate which together with the voltage applied to the first plate establishes a positive offset voltage with respect to the target voltage. Applying incrementally changing voltage levels to the second end of the second plate, which varying voltage levels change the voltage at the second end of said second plate of each set to vary the length of the capacitive structure above the target voltage.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a thin film capacitive structure for testing according to this invention with various test voltages shown in conjunction therewith;
FIGS. 2–4 are views similar to FIG. 1 showing different test voltages applied;
FIG. 5 is a plan view of the top plate of a capacitive device test structure suitable for both transverse and orthogonal testing of scanning;
FIG. 6 is a sectional view taken substantially along the plane designated by the line 6 — 6 of FIG. 1 ; and
FIG. 7 depicts another embodiment for testing a capacitive structure according to this invention.
DETAILED DESCRIPTION
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and for the present to FIG. 1 , a thin film capacitor 10 , structured for testing according to this invention, is shown. It is to be understood that this invention, as disclosed, is primarily for the purpose of research testing, and is somewhat different from a structure used in production, although such use is not precluded.
The capacitor structure 10 is comprised of top or upper plate 12 having a plurality of individual electrically conductive sections 14 joined by a central conductor 16 . (As used herein, the term conductor means electrically conducting, unless otherwise noted, and, hence, can refer to either electrical conductors or semiconductors.) The structure of individual sections 14 is to facilitate isolating various sections of the capacitor structure 10 during testing as will become apparent presently. A conductive bottom or lower plate 20 is provided. A dielectric insulating material 22 separates the upper plate 12 and lower plate 20 to form the capacitor structure 10 . In the disclosed embodiment, which is for thin film capacitors, the sections 14 of the upper plate 12 are polysilicon about 0.15 microns thick, the central conductor 16 preferably is polysilicon about 0.15 microns thick, the lower plate 20 is silicon about 700 microns thick, and the dielectric insulating material 22 is oxinitride less than 4 nanometers thick. On the top plate, on the right side as seen in the figures, is an electrical contact 26 at the end of central conductor 16 . Also, a contact 28 is on the left side of the central conductor 16 , and a contact 29 is provided on the bottom plate 20 . A sectional view of the structure is shown in FIG. 6 . As will be described presently, by applying various voltages to the different contacts, the uniformity, or lack thereof, of the dielectric material 22 can be determined.
Before referring specifically to the drawings, and a detailed description of the technique, an overview of this technique will be given. First, a nominal value of the minimum voltage for tunneling to occur in the dielectric material 22 is determined, and this is referred to as the target value or target voltage 30 . One plate, e.g., bottom plate 20 , is set at a given voltage, i.e. ground or 0, and one end, e.g. contact 26 of the top plate 12 , is set at a voltage value that, with reference to the bottom plate 20 , is greater than or off set to the target value 30 . The opposite end of the top plate 12 , e.g. contact 28 , is set at a lower value such that, with reference to the bottom plate 20 , the voltage at that end of the top plate is below the target value; i.e. there is a voltage drop from one end of the top plate, e.g. contact 26 to the other end e.g. contact 28 . Hence, some portion of the capacitive structure 10 , e.g., that to the right, is above the target voltage 30 , and electron tunneling will occur. The other portion of the capacitive structure 10 , e.g. that to the left, will be below the target voltage 30 and tunneling will not occur. The relative lengths of the two portions will depend upon the relative voltages of the contacts 26 and 28 , and the portion of the capacitive structure in which tunneling is occurring can be determined. By raising the voltage incrementally at contact 28 , length to the right of the capacitive structure at which tunneling occurs is increased and the length of the capacitive structure where tunneling does not occur is decreased. By measuring the increase in tunneling, sometimes referred to as scanning, the tunneling voltage at various locations can be calculated, as will be described presently. This technique is demonstrated in FIGS. 1–4 .
In FIG. 1 , the bottom plate 20 is maintained at a given voltage; in this case, 0 or ground Voltage, and the entire top plate is maintained at a given voltage, i.e. 2 volts so that the voltage between the bottom plate 20 and the top plate 12 is an offset 32 above the target voltage 30 across the entire capacitive structure, as shown in the shaded area 34 in FIG. 1 . In this case, the tunneling effect will be equal to the average tunneling value across the entire capacitive structure 10 , irrespective of variations in the dielectric 22 at various locations along the capacitive structure.
Referring now to FIG. 2 , there is depicted the situation wherein the left side of the top plate 12 has the voltage maintained at a level which is substantially below the target voltage 30 , while the right side is maintained at the 2 volt level. With the voltage drop from right to left on the top plate, the voltage across the plates 20 and 12 drops below the target voltage at the location 36 ′. Thus, only the shaded portion 34 ′ is above the target voltage and, hence, tunneling is occurring only in this section of the capacitive structure corresponding to the shaded portions 34 ′, and not across the entire capacitive structure 10 . The amount of tunneling is measured in this section.
Referring now to FIG. 3 , the voltage has been raised an increment at contact 28 so that it is higher than the voltage of FIG. 2 , but less than the target voltage. This will move the position of location 36 ′ where the voltage drops below the target voltage 30 , to the left, so that the shaded area 34 ″, which is a larger area than shaded area 34 ′, represents the corresponding section of the capacitive structure 10 in which tunneling is occurring and is measured. The increase in tunneling as a function of the increase in the length of the capacitive structure is determative of the relative homogeneity of the dielectric material 22 between the section 34 ′ measured in FIG. 2 and the increase in section 34 ″ shown in FIG. 3 . It should be noted that while the objective is to change the voltage at the left hand side of FIG. 2 to that of FIG. 3 , the most precise way is not to directly control the voltage at location 28 , but to control the current flowing between the contact 26 and contact 28 since current can be more precisely controlled, and since there is a voltage differential between contact 26 and 28 , current will flow of course, since E=IR.
FIG. 4 shows yet another incremental increase of the voltage at the left side of upper plate 12 above that shown in FIG. 3 , but still below the target voltage 30 . This will move the location 36 ′″ to the left of location 36 ″ shown in FIG. 3 , again increasing the shaded area 36 ′″, thus increasing the area of the capacitive structure in which tunneling occurs. It is to be understood that the method has been described by starting with a voltage at the left side of the plate at a voltage below the target voltage, and then incrementally increasing the voltage. However the method can also start with the left hand side having a voltage equal to or greater than the target voltage, and then incrementally decreasing the voltage. Also it is to be understood that the terms “right” and “left” and “top” and “bottom” merely designate the locations and orientations in the drawings as depicted, and the locations and orientations could be reversed or otherwise changed.
As indicated earlier, for test purposes, it is preferred that the top plate 12 be formed in discrete sections since this allows for better incremental discrete measurements of tunneling. Indeed, the width of the sections 14 in large measure determines the increments used to vary the voltage.
If desired, the entire process can be repeated going in the opposite direction, e.g. keeping a constant voltage on the contact 28 , and varying the voltage on contact 26 , and also scanned orthogonally if desired. FIG. 5 shows a preferred top plate 12 ′ construction for longitudinal and orthogonal scanning. In this embodiment the top plate is formed in sections 14 ′ with perpendicular conductors 16 ′. This construction allows both transverse and orthogonal scans to be made.
If a location is identified as having electron tunneling at a lower voltage than the target voltage, this region can then be subjected to failure analysis tests.
Also, it is possible to start both contacts 26 and 28 at the same offset voltage, and then reducing one incrementally, rather than the opposite. In this case the starting voltage would look like FIG. 1 , and the last incremental scan would look like FIG. 2 .
Various formulae to calculate tunneling effects are as follows: Current is forced for constant dX/dl across structure after establishing target voltage and Vbias above target voltage (bias where defective tunneling current is measurable during normal voltage ramp testing and additional offset above target voltage, respectively).
The measured tunneling current of the structure on the preceding page should have discernable steps where the tunneling contribution of each capacitor leg adds to the total as X (point along the structure where target voltage is attained) is swept across the structure.
Formulae where Vtarget=Target bias, Voffset=Offset bias, Vtotal=Target bias+offset bias (total voltage applied to the right side), V′o=Resulting Voltage in forcing current referenced to Vtotal, L=Length of the structure, R=Resistance of the structure, X′=initial position along L (position when Vforced=lower plate voltage; or V′o=Vtotal), X=position along L from the Vtotal side, Iforced =forced Current, X=(Voffset/Vtotal)*L, I=V′o/R=(Voffset/R)*(L/X), V forced=Vtotal−V′o. A slightly modified embodiment, the initial set voltage at contact 26 is set at about the target voltage, and the voltage at contact 28 again is set below target voltage and increased incrementally. This will determine if any locations of the capacitive structure have dielectric material 22 that tunnels below the target voltage.
Referring now to FIG. 6 another embodiment of the invention is shown. In this embodiment each segment of the upper plate 14 is tested against another segment of the upper plate for leakage through the dielectric material there under between the bottom plate 20 . As shown in FIG. 6 , one top segment, designated as 14 a is tested against another segment designated as 14 b. In this case the bottom plate is 20 is divided into individual segments designated 20 a and 20 b under plate segments 14 a and 14 b respectively. The segments 14 a and 20 a and 14 b and 29 b are separated by insulating sheet not shown in this Figure. In this embodiment top segment 14 a has a pair of spaced contacts 40 a and 42 a, and top segment 14 b has a pair of spaced contacts 40 b and 42 b. The bottom segments 20 a and 20 b are connected to opposite sides of a differential amplifier 46 to amplify the difference between sensed current or voltage at 20 a and 20 b.
In operation, each of the plate segments 20 a and 20 b is maintained at a given voltage below the target voltage, e.g. at ground. The contacts e.g. 40 a and 40 b at one end of each segment 14 a and 14 b are maintained at the target voltage, as described above and the contacts e.g. 42 a and 42 b are maintained at a voltage level below target value and the electron tunneling at each section 20 a and 20 b is measured. If for any given voltage level there is any significant difference in the sensed level, then this is an indication that there needs to be failure analysis of the insulating dielectric material.
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A method of determining electron tunneling values at various locations in a capacitor structure having a first and a second conductive plate with a dielectric material disposed there between, wherein each plate has first and second ends, including the steps of: determining the nominal tunneling voltage of the dielectric material at its thickness to provide a target voltage. Applying a first voltage level equally across the first plate. Applying a second voltage level to the first end of the second plate which together with the voltage applied to the first plate establishes a positive offset voltage with respect to the target voltage. Applying incrementally changing voltage levels to the second end of the second plate, which varying voltage levels change the voltage at the second end of the second plate of each set to vary the length of the capacitive structure above the target voltage.
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BACKGROUND OF THE INVENTION
The present invention relates to a switching circuit.
A composite technique has been developed to form different kinds of elements in a single semiconductor substrate, to obtain a semiconductor integrated circuit having diverse functions and a high degree of integration.
For instance, a circuit technique for combining bipolar transistors with insulated gate-type fieldeffect transistors (hereinafter referred to as MOSFET's) has been disclosed in Japanese Patent Publication No. 43997/1972 and in Japanese Patent Laid-Open No. 26181/1977.
FIG. 1 shows a switching circuit which was contrived by the inventors of the present invention and in which a bipolar transistor and an insulated gate-type field effect transistor are combined. (See U.S. Pat. Ser. No. 513,056 which is hereby incorporated by reference.) The circuit shown in FIG. 1 is an input buffer circuit (switching circuit) used for, for example, in a Bi-CMOS (bipolar/CMOS mixed type) gate array. The circuit consists of two bipolar transistors Q1, Q2 that constitute an output stage, a CMOS inverter 12 which drives the bipolar transistor Q1 in an inverted manner, and a buffer amplifier (voltage follower) 14 which drives the other bipolar transistor Q2 in a non-inverted manner.
This circuit operates as described below. A logic signal applied to an input terminal IN is divided into two branches. One part of the input is phase inverted by the CMOS inverter 12 and is input to the base of the transistor Q1 of the output stage. The other part of the input is converted into a low impedance by the buffer amplifier 14 and is input in phase to the base of the other bipolar transistor Q2 of the output stage. Therefore, the two bipolar transistors Q1, Q2 in the output stage are rendered conductive and are driven in a complementary manner. When one transistor Q1 is ON (conductive) and the other transistor Q2 is OFF (nonconductive), a changing current is supplied to the load Co through the transistor Q1. When one transistor Q1 is OFF and the other transistor Q2 is ON, the electric charge stored in the load Co is discharged through the other transistor Q2. Accordingly, the capacitive load Co is driven in this fashion.
The switching circuit has the features (effects) described below.
(1) The CMOS inverter 12 and the buffer amplifier circuit 14 have nearly the same signal transmission speed; hence, the bases of the two transistors Q1, Q2 are driven nearly at the same timing in an opposite phase relation. Therefore, the two transistors Q1, Q2 are turned on simultaneously for only a short time, making it possible to decrease the through current.
(2) The two transistors Q1, Q2, which are of the npn-type, can be used to constitute the output stage. When a semiconductor integrated circuit is constructed, therefore, a high cut-off frequency f T can be easily obtained to realize a high operation speed.
(3) When the bipolar transistor Q1 in the output stage is turned off, the electric charge accumulated in the base thereof can be quickly extracted through a MOSFET M2 of the CMOS inverter 12. When the other bipolar transistor Q2 in the output stage is turned off, the electric charge accumulated in the base thereof can be quickly extracted by a low-impedance output of the voltage follower 14. That is, the two bipolar transistors Q1, Q2 in the output stage, respectively, have paths for effectively extracting the electric charge accumulated in the bases. Therefore, the switching time from ON to OFF is conspicously shortened.
(4) Since a power source terminal p1 of the voltage follower 14 is connected to the output terminal OUT, the discharging current of the capacitive load Co connected to the output terminal OUT flows not only to the other transistor Q2 in the output stage but also to the voltage follower 14 as an operation current from the first power source terminal p1. At the moment when the logic state of the buffer output OUT changes from "H" (high logic level) to "L" (low logic level), the electric charge stored in the load Co is allowed to discharge through the transistor Q2 and the voltage follower 14. Therefore, the driving power is greatly reinforced for the capacitive load Co, especially at the moment of breaking.
(5) Further, since the CMOS inverter 12 and the voltage follower 14 have high input impedances, there is obtained a high input impedance as viewed from the input side.
(6) The first power source terminal p1 of the voltage follower 14 is connected not to the power source V DD but to the collector (output terminal OUT) of the transistor Q2 of the output stage, and the base potential of the transistor Q2 is not higher than the collector potential thereof. Therefore, the transistor Q2 is not saturated.
The switching circuit exhibits excellent features as described above. Further study of the problem enabled the inventors to realize the switching circuit in the form of an integrated circuit. They have found that in designing constants for the circuit, many contrivances are necessary to satisfy the high-speed characteristics and the low power consumption that are strictly necessary for the switching circuit. The present invention was achieved through the above study.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a novel switching circuit having high performance, that can be suitably realized in the form of a semi-conductor integrated circuit.
The switching circuit is constructed as described below.
(1) The circuit comprises two npn-type bipolar transistors Q 1 , Q 2 in the output stage connected in the form of a totem pole, CMOS inverters M 1 , M 2 for driving the base of the transistor Q 1 , a source follower M 3 for driving the base of the transistor Q 2 , a resistor R of which the one end is commonly connected to the base of the transistor Q 2 and to the source of the source follower M 3 , and an input signal terminal commonly connected to the gate of the source follower M 3 and to the gate of the CMOS inverters M 1 , M 2 .
(2) A threshold voltage V thNO of n-channel MOSFET's constituting the CMOS inverters is selected to be substantially equal to a threshold voltage V thNO of the MOSFET (source follower) M 3 . Here, the threshold voltage V thNO stands for that of the n-channel MOSFET when there is no substrate effect.
(3) Resistance of the resistor R is selected to lie over a predetermined range in order to set the turn-on time and the turn-off time of the NPN bipolar transistor Q 2 to be shorter than a predetermined value.
(4) The channel conductance Wn/Ln of the source follower M 3 has been so set that the threshold voltage V LT2 of the source follower M 3 will be close to the threshold voltage V LT1 of the CMOS inverters. Here, Ln denotes gate length, and Wn denotes gate width.
Owing to the above-mentioned structure, a high-speed switching circuit which permits little through current to flow can be obtained without increasing the complexity of IC manufacturing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram showing fundamental circuit structure of the switching circuit that serves as a prerequisite of the present invention;
FIG. 2 shows structure of the switching circuit according to the first embodiment of the present invention;
FIG. 3 is a diagram showing the relation between the resistance of the resistor R and the threshold voltage V LT2 of the source follower circuit;
FIG. 4 is a diagram showing the relation between the resistance of the resistor R and the turn-on and turn-off times of the bipolar transistor Q2;
FIG. 5 is a circuit diagram illustrating a second embodiment of the present invention;
FIG. 6 is a circuit diagram illustrating a third embodiment of the present invention; and
FIG. 7 is a circuit diagram illustrating a fourth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
FIG. 2 is a circuit diagram which concretely illustrates a first embodiment of the present invention.
The present invention was achieved through the study of how to reduce the through current of the switching circuit, how to increase the signal transmission speed, and how to realize the switching circuit in the form of a semiconductor integrated circuit.
Therefore, the progress of study by the inventors will first be described below, and the features of the present invention will then be described.
The circuit shown in FIG. 2 was studied by the inventors through the process as mentioned below.
I. Consideration of logic threshold voltage V LT1 of the CMOS inverter 12:
The substrate effect takes place if the source S of NMOS-FET M 2 is connected to the base of the transistor Q 2 as indicated by a solid line. Here, the term "substrate effect" means that if the source potential so changes as to become higher than or lower than the ground potential while the potential of the silicon substrate has been fixed to ground potential, the practical threshold voltage of the MOSFET changes depending upon the change in the source potential. If the substrate effect is taken into consideration, therefore, the threshold voltage V thN of NMOSFET M 2 in practice is given by the following well-known equation: ##EQU1## where V thNO denotes threshold voltage when there is is no substrate effect,
ΔV th denotes shifted amount caused by the substrate effect,
K denotes a constant,
2φ F denotes voltage that is twice as great as the Fermi potential φ F ,
V BS denotes voltage across the substrate and the source of the NMOSFET M 2 , and
V BE denotes voltage across the base and the emitter of the transistor Q 2 .
Next, ##EQU2## is defined below.
In the above equation, β P and β N denote conductance (constant) of the p-channel MOSFET and conductance of the n-channel MOSFET, respectively, and β PO and βNO denote values of β P and β N , respectively, when W/L=1 (where W is gate width and L is gate length).
Then, a logic threshold voltage V LT1 of the CMOS inverter 12 is given by, ##EQU3## where V DD is power source voltage, and
V thPO denotes the threshold voltage of PMOSFET M 1 when there is no substrate effect.
Generally, α is set to a suitable value to so design the circuit that V LT1 ≈1/2V DD (note here that the symbol ≈ is used to indicate "substantially equal to"). Here, the threshold voltage V LTl of the CMOS inverter stands for a gate voltage applied to the CMOS inverter when an electric current flows substantially equally into the PMOSFET M 1 and NMOSFET M 2 that constitute the CMOS inverter.
II. Consideration of the logic threshold voltage V LT2 of the NMOS source follower circuit:
It is assumed for purposes of beginning the analysis that the logic threshold voltage V LT2 for turning the NMOSFET M 3 and the transistor Q 2 from off to on, is ##EQU4##
III. Consideration of through currents of the transistors Q 1 , Q 2 :
To prevent the flow of through currents of the transistors Q 1 , Q 2 , the relation V LT1 ≈V LT2 must hold true. If V DD =5 volts, V LT1 ≈2.5 volts. In order for the logic threshold voltage V LT2 to be 2.5 volts when V BE =0.6 volt, it is necessary to implant impurity ions into the channel region of the NMOSFET M 3 , so that V thNO will become 1.9 volts. Here, V thPO of M 1 is -0.6 volt and V thNO of M 2 is +0.6 volt. To set the threshold voltage V thNO of NMOSFET M 3 to 1.9 volts, therefore, the individual MOSFET's, M 2 and M 3 must be formed through individual processes, or must be formed through processes that are partly common to each other; then, the desired threshold voltages of each of the MOSFET's must be obtained through additional processes.
IV. Consideration of the NMOS source follower M 3 and the logic threshold voltage V LT2 of the transistor Q 2 :
The inventors have furthered the study concerning the logic threshold voltage V LT2 , and have found the fact that the logic threshold voltage V LT2 is not simply found from the equation (3) above but varies with the resistance of the resistor R as well as β NO of NMOSFET M 3 and W N /L N of NMOSFET M 3 , as shown in FIG. 3.
The reason why the logic threshold voltage V LT2 varies according to the relation shown in FIG. 3 will be analyzed below.
Here, if ##EQU5## the current that flows through the drain-source path of the NMOSFET M 3 is: ##EQU6## where V GS denotes the voltage across the gate and the source of NMOSFET M 3 .
Input voltage V IN at the input terminal IN is:
V.sub.IN =V.sub.GS +R·I.sub.DS (5)
The transistor Q 2 is rendered conductive when the voltage drop R·I DS of the resistor R satisfies the following equation:
V.sub.BEQ.sbsb.2 =R·I.sub.DS (6)
From equations (5), (6), there is obtained,
V.sub.GS =V.sub.IN -V.sub.BE (7)
From equations (4), (7), there is further obtained, ##EQU7##
If both sides of the equation (8) are multiplied by R, and if V BE =R·I DS is taken into consideration, there is obtained the following equation: ##EQU8##
By modifying equation (9), there is obtained, ##EQU9##
By modifying equation (10), there is further obtained, ##EQU10##
From equation (12), it will be understood that the logic threshold voltage V LT2 also varies depending upon β NO , W N /L N and R. FIG. 3 shows the relation between the resistance of the resistor R and the threshold voltage V LT2 of the NMOSFET M 3 relying upon the results measured according to the present invention, wherein a solid line represents the relation when W N /L N =10μm/2μm, a dot-dash chain line represents the relation when W N /L N =20/2, and a two-dot chain line represents the relation when W N /L N =40/2.
V. Consideration of the relation between the resistance of the resistor R and turn-on time t ON and turn-off time t OFF of the transistor Q 2 :
FIG. 4 shows the relation between the resistance of the resistor R and t ON , t OFF , that is practically examined.
In FIG. 4, the solid line represents the turn-on time t ON , and a dotted line represents the turn-off time t OFF .
The following facts will be understood from FIG. 4.
(1) To set t ON and t OFF to be shorter than 2 nsec., the resistance must be selected to be 1KΩ<R<30KΩ (range A).
(2) To set t ON and t OFF to be shorter than 1.5 nsec., the resistance must be selected to be 3KΩ<R<20KΩ (range B).
(3) To set t ON and t OFF to be shorter than 1.25 nsec., the resistance must be selected to be 4KΩ<R<16KΩ (range C).
In the foregoing were mentioned the results studied by the inventors. The specific construction of the circuit shown in FIG. 2 will further be described below.
In FIG. 2, the source S of the n-channel MOSFET M 2 may be either grounded as indicated by a dotted line or be connected to the base of the transistor Q 2 as indicated by a solid line. When the source of the NMOSFET M 2 is connected to the base of the transistor Q 2 , however, it becomes difficult to design the threshold voltage V LT1 , of the CMOS inverter 12. When the source of the NMOSFET M 2 is grounded, it is easy to design the threshold voltage V LT1 .
The circuit of FIG. 2 is designed in four steps:
Step 1: The threshold voltage V thNO of NMOSFET M 2 is set to be substantially equal to the threshold voltage V thNO of NMOSFET M 3 . For instance, NMOSFET M 2 , M 3 are formed on the same chip by the same manufacturing process.
Step 2: The resistance R is set to lie within a predetermined range to set t ON and t OFF of the transistor Q 2 to be shorter than a predetermined value. For instance, to set t ON , t OFF to be shorter than 2 nsec., the resistance R is selected to lie within the aforementioend range A.
Step 3: Design the threshold voltage V LT1 of the CMOS inverter which consists of PMOSFET M 1 and NMOSFET M 2 . That is, when the source of the NMOSFET M 2 has been grounded, the constant of the parameter is determined as: ##EQU11## when the source of the NMOSFET M 2 has been connected to the base of the transistor Q 2 , the threshold voltage should be designed in accordance with the equation (2) mentioned earlier.
Step 4: Resistance R over the range mentioned in Step 2 is used so that the threshold voltage V LT2 of the NMOSFET M 3 will approach the threshold voltage V LT1 that is set in Step 3, and values β NO , W N /L N are set in accordance with the equation (12), such that V LT1 ≈V LT2 . Here, however, β NO serves as a constant that does not change once the manufacturing process is determined. In practice, therefore, V LT1 ≈V LT2 is accomplished by changing W N /L N of NMOSFET M 3 .
Described below is a concrete example when the above-mentioned design procedure is followed (where the source of NMOSFET M 2 is grounded in FIG. 2).
Step 1: Set V thNO of NMOSFET's M 2 and M 3 to be equal to each other.
Step 2: Set the resistance R to be 8KΩ so that the turn-on and turn-off times of the transistor Q 2 will be shorter than 1.25 nsec.
Step 3: Set the value W P /L P of PMOSFET M 1 constituting the CMOS inverter to be 30/2, and set the value W N /L N of NMOSFET M 2 to be 10/2.
Here, ##EQU12##
Therefore, ##EQU13##
Step 4: From the equation (12), there is obtained, ##EQU14##
Since V LTl =2.5 V≈V LT2 , if
V LT2 =2.5 V
V BE =0.6 V
V thN =0.6 V
are inserted into the equation (13), there is obtained, ##EQU15## If W N /L N is found from the equation (14), we obtain W N /L N ≈5/2. That is, the value W N /L N of NMOSFET M 3 should be set to 5/2.
The above-mentioned structure makes it possible to obtain the following effects in addition to the effects mentioned in the paragraph of Background of the Invention.
(1) The threshold voltage V thNO (when there is no substrate effect) of NMOSFET M 2 constituting the CMOS inverter 12 is set to be substantially equal to the threshold voltage V thNO (when there is no substrate effect) of NMOSFET M 3 . This means that the NMOSFET's M 2 and M 3 can be formed simultaneously in the semiconductor substrate through the same manufacturing process, thereby simplifying the manufacture of integrated circuits.
(2) Resistance of the resistor R is so determined that the bipolar transistor Q 2 in the output stage exhibits a turn-on time and a turn-off time of desired values (high speeds). Therefore, the high switching speed of the transistor Q 2 is correctly determined.
(3) Value W N /L N of the NMOSFET M 3 is so adjusted that the logic threshold voltage V LT2 of NMOSFET M 3 approaches the logic threshold voltage V LT1 of the CMOS inverter. Therefore, the two transistors Q 1 and Q 2 in the output stage are driven at nearly the same timing in a complementary manner, making it possible to minimize the through current that flows instantaneously through the transistors Q 1 , Q 2 .
Embodiment 2
FIG. 5 shows the structure of a switching circuit according to a second embodiment of the present invention. What makes this embodiment different from the circuit structure of embodiment 1 is that the resistor R in this embodiment is formed by utilizing the resistance of a MOSFET M 4 while it is conductive.
Similar to embodiment 1, the circuit in this embodiment is designed in five steps.
Step 1: The threshold voltage V thNO of NMOSFET M 2 is set to be substantially equal to the threshold voltage V thNO of NMOSFET M 3
Step 2: To set t ON of the transistor Q 2 (time required for turning Q 2 from off to on) to be shorter than a predetermined value, the resistance R of NMOSFET M 4 while it is conductive is set to lie within a predetermined range.
To set t ON to be shorter than 2 nsec., R must be greater than 1KΩ.
To set t ON to be shorter than 1.5 nsec., R must be greater than 3 KΩ.
To set t ON to be shorter than 1.25 nsec., R must be greater than 4KΩ.
Step 3: In order to set t OFF required for turning the transistor Q 2 from on to off to be shorter than a predetermined value, the resistance R of NMOSFET M 4 when it is turned from off to on is set to lie within a predetermined range, the NMOSFET M 4 being driven by a current that flows through a path consisting of input terminal IN, PMOSFET M 1 , and transistor Q 1 .
To set t OFF to be shorter than 2 nsec., R≦30 KΩ.
To set t OFF to be shorter than 1.5 nsec., R<20KΩ.
To set t OFF to be shorter than 1.25 nsec., R<16KΩ.
Step 4: Design the threshold voltage V LT1 of the CMOS inverter consisting of M 1 and M 2 . When the source of NMOSFET M 2 is grounded, design the threshold voltage according to the following equation, ##EQU16## When the source of NMOSFET M 2 is connected to the base of the transistor Q 2 , design the threshold voltage according to the aforementioned equation (2).
Step 5: Use the resistance R of NMOSFET M 4 over the ranges of Steps 2 and 3, that V LT2 will approach V LT1 that has been set in Step 4, and set β NO and W N /L N in accordance with the equation (12) to accomplish the relation V LT1 ≈V LT2 .
Embodiment 3
FIG. 6 is a diagram showing a switching circuit according to a third embodiment of the present invention.
The feature of this circuit resides in the provision of a collector-grounded pnp-type bipolar transistor Q 3 in the input portion.
If the circuit is based on the prerequisite that an input signal (high level V 1 H=2.0 V, threshold level V Ith =1.3 V, low level V 1 L=0.8 V) of the TTL level is applied to the input terminal IN, the threshold voltage V Ith of the transistor Q 3 must be set to 1.3 volts. In this case, the design should be carried out according to Steps 1 to 4, such that V LT1 =V LT2 =V Ith +V BE =1.3 V+0.6 V=1.9 volts.
Embodiment 4
According to this embodiment, shown in FIG. 4, the switching circuit is provided with a NOR logic function for a pair of input signals IN A and IN B relying upon a plurality of MOSFET's M1A, M1B, M2A, M2B, M3A and M3B. As can be seen in FIG. 7, the input IN A is coupled to the gates of M1A, M2A and M3A while the input IN B is coupled to the gates of M1B, M2B and M3B for similarly producing an output. By virtue of the series connection of M1A and M1B and the parallel connections of M2A and M2B as well as M3A and M3B, a NOR output at OUT will be produced for the inputs IN A and IN B . The transistor M 4 serves as the resistor R in this circuit in a manner similar to FIG. 5.
The design procedure for setting values for the transistors and the resistance is the same as the one described above.
Although particular values for voltages, resistances and dimensions have been provided in the foregoing description, it is to be understood that these are for purposes of example in conjunction with the described embodiments, and the present invention is not necessarily limited to such values. On the contrary, the principles and steps provided in the foregoing description can be used to design switching circuits having reduced through current for a variety of different values.
Also, although the invention is described in terms of MOSFET's (technically meaning Metal-Oxide-Semiconductor FETs), it is to be understood that this is done in the more general meaning now attached to this term, which includes other IGFETs (Insulated-Gate FETs) which may have their gates formed of material other than metal (e.g. doped polycrystalline silicon) and their gate insulation formed of material other than oxide (e.g. Si 3 N 4 ).
Further, although the fourth embodiment has been provided to show connection of the elements of the present invention in a logic NOR configuration, it is to be understood that the circuit could be arranged to provide other logic functions, if desired, while still operating with the CMOS inverter arrangement and source follower arrangement discussed for this invention.
It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of this invention. Numerous other arrangements may be readily devised by those skilled in the art which embody the principles of the invention and fall within its spirit and scope.
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A bipolar/CMOS mixed type switching circuit comprising two npn-type bipolar transistors Q 1 , Q 2 that are connected in the form of a totem pole in the output stage, a CMOS inverter and an NMOSFET M 3 for driving these transistors in a complementary manner, and resistance means R for discharging the electric charge stored in the base of the transistor Q 2 . The threshold voltage of an NMOSFET M 2 constituting the CMOS inverter in the absence of substrate effect is set to be substantially equal to the threshold voltage of the NMOSFET M 3 in the absence of the substrate effect, and the channel conductance W N /L N of the NMOSFET M 3 is so set that the threshold voltage V LT1 of the CMOS inverter and the practical threshold voltage V LT2 of the NMOSFET M 3 will be nearly the same. Owing to the above structure, there is obtained a switching circuit which permits little through current to flow and which operates at high speeds.
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BACKGROUND
[0001] Networks enable computers and other devices to communicate. For example, networks can carry data representing video, audio, e-mail, and so forth. Typically, data sent across a network is divided into smaller messages known as packets. By analogy, a packet is much like an envelope you drop in a mailbox. A packet typically includes “payload” and a “header”. The packet's “payload” is analogous to the letter inside the envelope. The packet's “header” is much like the information written on the envelope itself. The header can include information to help network devices handle the packet appropriately. For example, the header can include an address that identifies the packet's destination.
[0002] A given packet may “hop” across many different intermediate network devices (e.g., “routers”, “bridges” and/or “switches”) before reaching its destination. These intermediate devices often perform a variety of packet processing operations. For example, intermediate devices often perform packet classification to determine how to forward a packet further toward its destination or to determine the quality of service to provide.
[0003] These intermediate devices are carefully designed to keep apace the increasing deluge of traffic traveling across networks. Some architectures implement packet processing using “hard-wired” logic such as Application Specific Integrated Circuits (ASICs). While ASICs can operate at high speeds, changing ASIC operation, for example, to adapt to a change in a network protocol can prove difficult.
[0004] Other architectures use programmable devices known as network processors. Network processors enable software programmers to quickly reprogram network processor operations. Some network processors feature multiple processing engines to share packet processing duties. For instance, while one engine determines how to forward one packet further toward its destination, a different engine determines how to forward another. This enables the network processors to achieve speeds rivaling ASICs while remaining programmable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIGS. 1A and 1B are diagrams illustrating control of power consumed by processing engines of a network processor.
[0006] FIGS. 2A and 2B are diagrams of circuitry to control power consumed by processing engines of a network processor.
[0007] FIGS. 3 and 4 are flow-charts of processes to control power consumed by processing engines of a network processor.
[0008] FIG. 5 is a diagram of a network processor.
[0009] FIG. 6 is a diagram of a processing engine.
[0010] FIG. 7 is a diagram of a network forwarding device.
DETAILED DESCRIPTION
[0011] FIG. 1A depicts a network processor 100 that includes multiple processing engines 102 a - 102 n. The engines 102 a - 102 n may be programmed to perform a variety of packet processing operations such as packet classification, filtering, and forwarding, among others. As shown in FIG. 1A , when network traffic is high, packet processing duties may be shared by a large number of processing engines 102 a - 102 n. For example, FIG. 1A depicts engines 102 a - 102 n as having high power consumption (e.g., fully operational). However, when less network traffic passes through the network processor 100 , fewer engines may be needed. For example, in FIG. 1B , when the traffic load decreases (e.g., when the number of packets received drops), the network processor 100 can reduce power consumed by engines 102 b and 102 n. This power management technique can, potentially, lower the average power consumption of the network processor 100 . That is, near peak power consumption by each engine 102 regardless of traffic load consumes overall power at a nearly constant peak rate. Most of the time, however, the traffic load is less than peak. By managing power consumed by the engines based on network traffic, power consumption can be reduced by 50% or more. Reducing the power consumption of individual network processors can greatly reduce the power consumption of a device (e.g., a router) incorporating a large number of network processors. Additionally, this traffic-based power management scheme can, potentially, lengthen the life of a network processor, for example, by reducing heat and overall power use.
[0012] FIGS. 1A and 1B illustrate the underlying concept of engine 102 power management. The concept may be easily implemented in a wide variety of inexpensive ways. For example, FIG. 2A illustrates an implementation that controls engine 102 b - 102 n power consumption by combining a clock 104 signal with a power control signal associated with a given engine 102 b - 102 n. For example, in FIG. 2A , a logic gate 106 b ANDs the clock 104 signal with a power control signal 108 b. The gate 106 b output is fed to the clock input of engine 102 b. When the power control signal 108 b is low, the engine 102 b is effectively powered down and will cease operation, though the engine 102 b will draw a negligible amount of power. When the power control signal 108 b is high, the engine 102 b will receive a “normal” clock 104 signal and execute instructions. Thus, by controlling the power control signals 108 , software running on engine 102 a (or other hardware or software) can control power consumed by the engines 102 b - 102 n.
[0013] Another scheme to control engine power consumption is shown in FIG. 2B . In this implementation, engine 102 power consumption is controlled by a processor 110 other than an engine 102 (e.g., a general purpose processor or co-processor).
[0014] Changes in the set of engines 102 b - 102 n operating will likely necessitate changes in packet processing operations. For example, the assignment of packets or packet processing operations to engines may be dynamically altered to reflect the changing set of operating engines.
[0015] FIGS. 2A and 2B are merely illustrations of two of a wide variety of possible implementations. For example, instead of a power control line for each engine 102 being controlled, a given power control line may connect to and control the power consumed by a set of multiple engines 102 . Additionally, other implementations may feature other power consumption control mechanisms.
[0016] FIG. 3 depicts a flow-chart of a process to control power consumed by network processor engines. As shown, the process accesses data metering 120 the traffic load being handled by the network processor. For example, the network processor may maintain or access network statistics identifying how many bytes or packets were received and/or transmitted in a given interval. Such statistics may be maintained by the network processor or an attached network device such as a media access controller (MAC). Based on the traffic load, the process controls 122 engine power consumption. For example, for lesser traffic loads, one or more engines may be powered down.
[0017] The process may be implemented in a variety of ways. For example, a given packet processing design may assign different traffic flows to different engines. For instance, a packet may be classified as belonging to a particular Quality of Service (QoS) flow or a particular Transmission Control Protocol (TCP)/Internet Protocol (IP) flow (e.g., a flow based on IP source and destination addresses and TCP source and destination ports). Based on the flow, the packet may be assigned for processing by a particular engine. The flow/engine assignments may be made to concentrate the number of engines used to service the flows. For example, the flow or packet processing capacity of an engine may need to reach some level before an additional engine is powered up. Additionally, when the last flow currently assigned to an engine terminates, the engine may be powered down until again needed. Potentially, the traffic load of different flows may be individually measured, for example, to determine how many flows can be assigned to an engine.
[0018] The techniques used to manage power consumption of the different engines may be done in a wide variety of ways. For example, FIG. 4 depicts a scheme that selects a number of engines to power based on the traffic load repeatedly falling within a given range. As shown in FIG. 4 , a process accesses 130 traffic metering data. The traffic load is then classified 132 , 134 , 136 as falling within a given traffic level. Once a level is determined (e.g., level 1 in FIG. 4 ), the process can increment 138 a counter associated with that level and zero 140 the counters associated with other levels. The zero-ing 140 and subsequent comparison 142 of the level's counter with a threshold can ensure that the traffic load remains at a given level for some period of time before altering the set of engines being powered. This can avoid “thrashing” that very rapidly powers up and powers down a given engine. When the level counter exceeds 142 some threshold, the set of engines powered is set 144 to reflect the load and the counter for that level is zeroed 146 . The process repeats for subsequent intervals.
[0019] The engines selected for a given level of traffic may be preset. For example, the power control circuitry may always power engines “1” and “2” when a given traffic level is detected. Alternately, the engines may be selected for powering based on a variety of factors such as existing load or flows.
[0020] FIG. 5 depicts an example of network processor 200 . The network processor 200 shown is an Intel® Internet exchange network Processor (IXP). Other network processors feature different designs. The network processor 200 shown features a collection of packet processing engines 102 on a single integrated circuit. Individual engines 102 may provide multiple threads of execution. As shown, the processor 200 also includes a core processor 210 (e.g., a StrongARM® XScale®) that is often programmed to perform “control plane” tasks involved in network operations. The core processor 210 , however, may also handle “data plane” tasks.
[0021] As shown, the network processor 200 also features at least one interface 202 that can carry packets between the processor 200 and other network components. For example, the processor 200 can feature a switch fabric interface 202 (e.g., a Common Switch Interface (CSIX)) that enables the processor 200 to transmit a packet to other processor(s) or circuitry connected to the fabric. The processor 200 can also feature an interface 202 (e.g., a System Packet Interface (SPI) interface) that enables the processor 200 to communicate with physical layer (PHY) and/or link layer devices (e.g., MAC or framer devices). The processor 200 also includes an interface 208 (e.g., a Peripheral Component Interconnect (PCI) bus interface) for communicating, for example, with a host or other network processors. As shown, the processor 200 also includes other components shared by the engines 102 such as memory controllers 206 , 212 , a hash engine, and internal scratchpad memory.
[0022] The packet processing techniques described above may be implemented on a network processor, such as the IXP, in a wide variety of ways. For example, traffic metering and instructions to manage power consumption of the engines may be executed as one or more engine 102 threads. The metering and control operations may operate on the same engine 102 to minimize the “footprint” of the scheme and permit powering down of all but one of the engines 102 at times. An alternate scheme (e.g., FIG. 2B ) may implement the power control circuitry in the core 210 or other hardware, potentially, permitting powering down of all engines 102 .
[0023] FIG. 6 illustrates a sample engine 102 architecture. The engine 102 may be a Reduced Instruction Set Computing (RISC) processor tailored for packet processing. For example, the engines 102 may not provide floating point or integer division instructions commonly provided by the instruction sets of general purpose processors.
[0024] The engine 102 may communicate with other network processor components (e.g., shared memory) via transfer registers 192 a, 192 b that buffer data to send to/received from the other components. The engine 102 may also communicate with other engines 102 via neighbor registers 194 a, 194 b wired to adjacent engine(s).
[0025] The sample engine 102 shown provides multiple threads of execution. To support the multiple threads, the engine 102 stores program counters 182 for each thread. A thread arbiter 182 selects the program counter for a thread to execute. This program counter is fed to an instruction store 184 that outputs the instruction identified by the program counter to an instruction decode 186 unit. The instruction decode 186 unit may feed the instruction to an execution unit (e.g., an Arithmetic Logic Unit (ALU)) 190 for processing or may initiate a request to another network processor component (e.g., a memory controller) via command queue 188 . The decoder 186 and execution unit 190 may implement an instruction processing pipeline. That is, an instruction may be output from the instruction store 184 in a first cycle, decoded 186 in the second, instruction operands loaded (e.g., from general purpose registers 196 , next neighbor registers 194 a, transfer registers 192 a, and/or local memory 198 ) in the third, and executed by the execution data path 190 in the fourth. Finally, the results of the operation may be written (e.g., to general purpose registers 196 , local memory 198 , next neighbor registers 194 b, or transfer registers 192 b ) in the fifth cycle. Many instructions may be in the pipeline at the same time. That is, while one is being decoded 186 another is being loaded from the instruction store 104 . The engine 102 components may be clocked by a common clock input.
[0026] The engine 102 can implement engine power management in a variety of ways. For example, a thread operating on the engine 102 may maintain and alter values of an array of power control data. For example, each bit of a register may represent whether a particular engine should be powered up (bit=1) or down (bit=0). The values of the register may be sent to the engines via power control lines (e.g., as shown in FIGS. 2A and 2 B).
[0027] FIG. 7 depicts a network device 312 incorporating techniques described above. As shown, the device features a collection of line cards 300 (“blades”) interconnected by a switch fabric 310 (e.g., a crossbar or shared memory switch fabric). The switch fabric, for example, may conform to CSIX or other fabric technologies such as HyperTransport, Infiniband, PCI, Packet-Over-SONET, RapidIO, and/or UTOPIA (Universal Test and Operations PHY Interface for ATM).
[0028] Individual line cards (e.g., 300 a) may include one or more physical layer (PHY) devices 302 (e.g., optic, wire, and wireless PHYs) that handle communication over network connections. The PHYs translate between the physical signals carried by different network mediums and the bits (e.g., “0”-s and “1”-s) used by digital systems. The line cards 300 may also include framer devices (e.g., Ethernet, Synchronous Optic Network (SONET), High-Level Data Link (HDLC) framers or other “layer 2” devices) 304 that can perform operations on frames such as error detection and/or correction. The line cards 300 shown may also include one or more network processors 306 that perform packet processing operations for packets received via the PHY(s) 302 and direct the packets, via the switch fabric 310 , to a line card providing an egress interface to forward the packet. Potentially, the network processor(s) 306 may perform “layer 2 ” duties instead of the framer devices 304 .
[0029] While FIGS. 5-7 described specific examples of a network processor, engine, and a device incorporating network processors, the techniques may be implemented in a variety of hardware, firmware, and/or software architectures including network processors, engines, and network devices having designs other than those shown. Additionally, the techniques may be used in a wide variety of network devices (e.g., a router, switch, bridge, hub, traffic generator, and so forth). Further, engine power consumption need not be all or (nearly) nothing. For example, different frequency clock signals may be fed to the engines.
[0030] The term packet was sometimes used in the above description to refer to an IP packet encapsulating a TCP segment. However, the term packet also encompasses a frame, TCP segment, fragment, Asynchronous Transfer Mode (ATM) cell, and so forth, depending on the network technology being used.
[0031] The term circuitry as used herein includes hardwired circuitry, digital circuitry, analog circuitry, programmable circuitry, and so forth. The programmable circuitry may operate on computer programs. Such computer programs may be coded in a high level procedural or object oriented programming language. However, the program(s) can be implemented in assembly or machine language if desired. The language may be compiled or interpreted. Additionally, these techniques may be used in a wide variety of networking environments.
[0032] Other embodiments are within the scope of the following claim.
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In general, in one aspect, the disclosure includes a description of a method that includes accessing network traffic metering data and controlling power consumption of individual ones of a set of network processor processing engines based on the metering data.
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FIELD OF INVENTION
The present invention relates to the field of defoaming equipment, and more particularly, to removing, defoaming, and storing large amounts of foam after a Blast Mitigation or Decontamination Foam has been used in either an open area or in a contained area.
BACKGROUND OF THE INVENTION
In the past, defoaming equipment was used primarily in the defoaming of carpets after a cleaning process. This was accomplished by vacuuming foam into a holding tank incorporated in a carpet cleaning machine and passively mixing it with some type of liquid defoamer. An example of such a system appears in U.S. patent application Ser. No. 5,813,086. This was done to break down the detergent in a simple and inexpensive manner, thereby reducing the space required to contain the spent liquid.
Current generations of Blast and Decontamination Foams are considerably thicker and more stable than industrial cleaning foams, are much harder to break down, and readily produce copious amounts of additional foam when agitated; all aspects that render conventional defoaming techniques impractical. These new foams include, for example, those described in U.S. patent application Ser. No. 6,405,626, issuing on Jun. 18, 2002 and titled “Decontaminating and Dispersion Suppressing Foam Formulation”, and in U.S. patent application Ser. No. 6,553,887, issuing on Apr. 29, 2003 and titled “Foam Formulations”. There is a need for a method of, and an apparatus for breaking down and collecting these new foams.
These new foams may be employed in a variety of manners. For example, Blast Mitigation Structures have been developed such as those described in U.S. patent application Ser. No. 6,439,120, issuing on Aug. 27, 2002, and titled “Apparatus and Method for Blast Suppression”. In short, this patent describes the process of placing a fabric tent-like structure over a suspect package, filling the tent with Blast Mitigation Foam, and detonating the suspect package. The tent-like structure and Blast Mitigation Foam absorb the energy of the explosion and contain any contaminants. The contents of the Blast Mitigation Structure must then be removed and disposed of, while minimizing the risk of exposing technicians and/or the environment to hazardous materials. This is also preferably done without coating the Blast Mitigation Structure with defoaming compound, which might compromise the use of the Blast Mitigation Structure in the future. Presently, there are no effective ways of doing this.
Similarly, various foams may be used to decontaminate vehicles or surface areas exposed to chemical, biological or radiological components or similar threats. No effective means or methods of collecting such decontaminant foams are currently available.
There is therefore a need for a method of and apparatus for defoaming, provided with consideration for the problems outlined above.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide an improved method of, and an apparatus for defoaming, which obviates or mitigates at least one of the disadvantages described above.
The present invention allows for the defoaming of Blast Mitigation Foam systems (such as the Universal Containment System available from Allen-Vanguard Corporation) as well as small or large scale Area Decontamination or Containment Foams.
This is accomplished by first mixing a measured amount of defoaming liquid to the proper ratio of water in a holding tank. Any defoaming agent can be used with the mechanical system of the described invention. In order to break the foaming capability of the originally dispensed foam, the defoaming agent must simply have a lower surface tension than the surfactant used to generate the foam in the first place.
The defoaming agent is then pumped through a series of hoses dispensing it into the collected foam through one or more injectors located near a vacuum nozzle head and again through one or more injectors located where the suction hose enters the holding tank. The defoaming agent is constantly re-circulated throughout the system to continually provide contact with the foam that is being extracted.
When used with a Blast Mitigation Structure (BMS), the foam is brought in through an arcuate vacuum suction nozzle, specifically designed to accommodate the BMS. The arcuate nozzle has been designed to present a very low profile to minimize any residue remaining in the tent, and is shaped to match the floor opening of the BMS so that it can extract the foam from within the tent over the largest possible area, with minimum risk of coming into contact with and possibly triggering, an explosive device that the system is containing.
The same process and apparatus may be used to collect foam from the decontamination of vehicles or areas. It is preferred to use an elongated nozzle to perform such defoaming, the elongated nozzle having a squeegee surface on three sides to help direct the suction and draw the foam in.
The system will break down and retain Blast Mitigation Foam and Area Decontaminating Foam containing pertinent forensic evidence. The system will also break down and retain Blast Mitigation Foam and Decontaminating Foam containing the by-products of chemical, biological, and radiological particles.
The holding tank on this system can be removed and replaced when full capacity is reached. This allows continued defoaming, almost immediate gathering of evidence, and quick containment and scientific study for the presence of chemical and biological by-products as well as radiological particles.
According to an embodiment of the invention there is provided an apparatus for defoaming, comprising: a vacuum system for collecting foam, the vacuum system including a vacuum head for drawing the foam through a suction hose terminating in a nozzle, the vacuum system feeding the foam into a holding tank; the holding tank initially storing a quantity of defoaming agent; and a pump for drawing the defoaming agent from the holding tank and feeding the defoaming agent to at least one injector, the at least one injector being fitted on the vacuum-side of the vacuum system, whereby the defoaming agent is actively mixed with the collected foam, reducing the collected foam, and the reduced foam and defoaming agent are recirculated through the pump; the nozzle, the suction hose, the vacuum system, the at least one injector and the holding tank being of chemical-resistant construction.
According to another embodiment of the invention there is provided a method of defoaming comprising the steps of: collecting foam using a vacuum system, the vacuum system including a vacuum head for drawing the foam through a suction hose terminating in a nozzle, the vacuum system feeding the foam into a holding tank; initially storing a quantity of defoaming agent in the holding tank; and drawing the defoaming agent from the holding tank and feeding the defoaming agent to at least one injector using a pump, the at least one injector being fitted on the vacuum-side of the vacuum system, whereby the defoaming agent is actively mixed with the collected foam, reducing the collected foam, and the reduced foam and defoaming agent are recirculated through the pump; the nozzle, the suction hose, the vacuum system, the at least one injector and the holding tank being of chemical-resistant construction.
This summary of the invention does not necessarily describe all features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
FIG. 1 presents a perspective, partially-exploded view of a defoaming system in an embodiment of the invention;
FIGS. 2A and 2B present front and side views respectively, of the defoaming system of FIG. 1 , further including a holding tank and lid for the holding tank;
FIG. 3 presents an electrical and process schematic in an embodiment of the invention;
FIG. 4 presents a detail of the electrical wiring in an embodiment of the invention;
FIGS. 5A , 5 B and 5 C present top, side and perspective views of an arcuate nozzle in an embodiment of the invention; and
FIGS. 6A , 6 B and 6 C present bottom, side and perspective views of an elongated nozzle in an embodiment of the invention.
DETAILED DESCRIPTION
An exemplary apparatus for implementing the invention will be described with respect to the embodiments appearing in FIGS. 1-6 . A partial parts list of the components used in these embodiments is summarized in the following table:
DEFOAMER MATERIALS LIST
Item
Part
Part Description
Part #
Supplier
10
Vacuum Head
ShopVac
ShopVac
12
BMF Nozzle
Suction Nozzle (BMF)
TD-DF-007
VRS
14
SDF Nozzle
Suction Nozzle (SDF)
TD-DF-008
VRS
16
Suction Hose
2½″ Hose
18
Holding Tank
65 Gal. Overpack
1065-YE
Enpac
20
Pump
Diaphragm Pump
2088-594-500
SHURflo
22 & 24
Mixing Nozzle
Kynar VeeJet
H-1/8-V V -KY 120 08
John Brooks
26 & 28
Return Nozzle
Kynar VeeJet
H-1/8-V V -KY 120 08
John Brooks
30, 32 &
Outlet Line
⅛″ Tubing G3
34
36 & 38
Return line
⅛″ Tubing G3
40
Ball Valve
¼″ Female × Female
42
Drop Tube
⅝″ Tubing
44
Inlet Line
½″ Tubing
46
Outlet Line
½″ Tubing
48
Holding Tank Lid
Enpac
FIG. 1 presents a perspective view of the components of the system, with the holding tank 18 removed so that the interior drop tube 42 can be seen. The lid 48 of the holding tank 18 is also not shown in FIG. 1 so that the relationship of the pump 20 and other components can be seen. All of these components, including the lid 48 and holding tank 18 , are shown in FIGS. 2A and 2B . The pump 20 and other components are shown in a partially exploded view in FIG. 1 , but are generally mounted on the lid 48 of the holding tank 18 as shown in FIGS. 2A and 2B . The pump 20 may be mounted directly on the lid 48 , supported by standoffs or some other for of bracket.
FIG. 3 presents the same system schematically, showing both the electrical control and process flow. The electrical control is quite simple in this embodiment as the pump 20 and vacuum head 10 are powered and controlled independently of one another, from 120 VAC sources via separate electrical cords V 1 and V 2 . These two devices may be are turned on and off with manual electrical switches, or alternatively, a simple electrical interlock system may be employed to ensure that the pump 20 only operates when the vacuum head 10 is running (to prevent defoaming agent from accidentally pouring out through the nozzle 12 , 14 ). Other safety interlocks may also be provided, for example, to shut the system down in the event that the holding tank 18 is full, or missing.
FIG. 4 presents an exemplary electrical control system in which the pump is hard-wired to a toggle switch 50 , which receives power from the line side of a 120 VAC insulated receptacle 52 . The insulated receptacle 52 is used to bring power to the vacuum head 10 , and is powered by an electrical cord V 3 .
In the operation of the defoaming system a measured amount of defoaming solution is mixed with a measured amount of water and is poured into the holding tank 18 . The holding tank 18 may consist of any suitable container that vacuum head 10 may be mounted on, or may be connected to via suitable pipes or hoses. This may include, for example, a stock plastic container from ShopVac, or a sealable container suitable for storage and transport of radioactive or biological waste, or even containers permanently mounted on vehicles or trailers. The Enpac 1065-YE has the particularly convenient features of being nestable, having a gasketed lid which seals the contents, being approved for use as a waste handling container and being fabricated of a relatively chemically inert polyethylene.
The pump 20 is turned to the on position and the defoaming solution is drawn up the drop tube 42 through inlet line 44 to pump 20 . The defoaming solution is then brought through the pump 20 into outlet line 46 , it is allowed free travel down return line 38 to tank return nozzle 26 through return line 36 and into tank return nozzle 28 . This is the re-circulate only mode.
Pump 20 identified above is a self-priming diaphragm pump which operates on 120 VAC, and deliveries a flow rate of up to 3 gallons per minute (though the flow rate does vary with the back pressure). Like the other components of the system, the portions of the pump 20 that are in contact with the defoaming agent and foam being collected are made of chemically resistant materials. Of course, other similar pumps could also be used. The voltage for the pump, for example could be specified to match whatever voltage is locally available.
The spray nozzles 22 , 24 , 26 and 28 are KYNAR™ VeeJet™, small capacity injectors, which provide a flat spray that is easy to align. They are also made out of chemical and corrosion-resistant material. Other injectors could also be used.
There are many suitable wet/dry vacuum heads 10 available, which again, are preferably of chemical resistant construction. The voltage for the vacuum head 10 should also match whatever is locally available.
As the remaining liquid flows past tank return nozzle 26 it is directed by a directional control valve 40 , such as a ball valve. If the solution reaches valve 40 in the closed position it is only allowed to circulate as described above. When valve 40 is in the opened position the solution travels down outlet line 30 diverting at the junction of outlet line 32 and outlet line 34 and out mixing nozzle 22 and mixing nozzle 24 .
Turning the power on at vacuum head 10 causes a vacuum in suction hose 16 . The vacuum in suction hose 16 causes the foam to be drawn in through suction nozzle 12 into suction hose 16 where it comes into contact with defoaming solution through mixing nozzles 22 and 24 . The foam continues up suction hose 16 through vacuum head 10 where it is hit again with the defoaming solution through return nozzles 26 and 28 .
At this point the foam has been brought back to a liquid state, falls into holding tank 18 is steadily sprayed from return nozzles 26 and 28 and the cycle continues.
The appropriate fittings, adapters, tubing, couplings, elbows, bushing, tees, straps and strainers required for any given implementation would be clear to the person skilled in the art.
FIGS. 5 and 6 present exemplary vacuum nozzles that could be used with the invention. Of course, other designs could also be used depending on the application. The details of these two designs are given hereinafter, with respect to the description of their particular applications. Exemplary applications of the invention are as follows:
Blast Mitigation Foam (BMF)
This form of defoaming can be used for many scenarios, three examples of which are given below:
1) In the case where a trained Security Guard discovers a suspect package, he would place a Blast Mitigation Structure (BMS) over the suspect package and fill said structure with Mitigating Foam (MF) rendering the area relatively safe. A suitable BMS would be, for example, the Universal Containment System available from Vanguard Response Systems. A suitable MF would be, for example, GCE-2000 available from Vanguard Response Systems.
The BMS would remain in place until the proper Law Enforcement Agency arrives at the scene. At this time Law Enforcement may wish to determine (through x-ray) whether the suspect package is a serious threat. At this point the MF must be evacuated in order to x-ray and place the desired detonating device. The system of the invention provides the only suitable way of performing this evacuation of the MF.
2) A BMS is placed over a suspect package by a trained Law Enforcement Officer and the desired detonating device is placed. The BMS is filled with MF and the package detonated. It is now desirable to collect any blast related evidence. The BMS can be lifted and the MF allowed to flow, but then the evidence would also be allowed to flow with it into tall grass or into drains, or through cracks and crevices. Similarly, if the package was a “dirty bomb” containing some form of contaminant, lifting the BMS would allow the contaminant to escape. Clearly, this is not desirable.
3) A BMS is placed over a suspect package by a trained Law Enforcement Officer, the package is X-rayed and then disruptors are suitably positioned for maximum effect. The BMS is filled with MF and the disruptors fired. It is now desirable to remove the foam to establish whether the disruptors had the desired effect, or if additional means have to be employed and the BMS refoamed. At the same time It is necessary to ensure that there is no loss of valuable forensic evidence throughout this process.
The suction nozzle of FIGS. 5A , 5 B and 5 C is specifically developed for non-interference with suspect packages when covered by the BMS. As shown, this suction nozzle is Vacuum Formed from a chemically-resistant polymer. The low profile of this suction nozzle allows it to be slipped under the edge of the BMS.
The indentations in the two arc-shaped plates 60 not only hold the nozzle together and space the two plates apart, and help distribute the suction from the vacuum. Without such distribution, the vacuum would tend to draw foam from a very small area, simply creating a hole, rather than drawing all of the foam more uniformly from the BMS.
In operation, the suction nozzle of FIGS. 5A , 5 B and 5 C is inserted into the BMS, and a vacuum applied to pull the MF from the BMS. As the MF is evacuated it is sprayed with the defoaming solution as it enters the vacuum hose first and then again as it enters the holding tank. This recycling of the defoaming solution continues until the MF is brought to a low enough height within the BMS to allow properly trained Law Enforcement personnel to safely perform their required tasks. The holding tank is then removed, capped and replaced. This allows each holding tank to be removed and its contents examined for possible forensic evidence.
Note that it may be desirable in some applications to include a strainer or screen over the suction nozzle. This might be desirable, for example, when used with a BMS to ensure that small items such as detonators are not collected into the holding tank of the defoaming system.
This operation remains the same with the presence of a chemical, biological or radiological threat.
Area Decontamination or Containment Foams
Area decontamination and containment foams are used where Chemical, Biological, Radiological or other hazardous materials have been discovered.
The Decontamination or Containment Foam is applied over the contaminated area eliminating the risk of further air born particles, and neutralizing chemical and biological agents.
Chemical and Biological Surface Decontamination
In the case of military type chemical or biological threats, Decontamination Foam will neutralize the Contaminating Agent after application and a stated contact time. In the case of other Hazardous materials foam can be used to contain dangerous off gassing to reduce the surrounding area affected. The Defoamer in this instance is primarily used as a high capacity clean up tool. It does however, hold the remaining active agent in close proximity with the decontamination solution allowing the contact time to effect more complete neutralization, and assists in the retention of any forensic evidence that may be present, and will help to suck up and store, for subsequent clean up operations, any hazardous liquids or powders that might be present.
Radiological Surface Decontamination
In the case of a radiological cleanup, decontamination solution is applied to prevent the radiological particles from becoming air born. During cleanup, the Defoamer holding tank 18 will contain this hazard allowing the clean up operation for transfer to another permanent storage container if required.
In the case of area decontamination a modified elongated nozzle 14 as shown in FIGS. 6A , 6 B and 6 C is used to collect the Surface Decontamination Foam (SDF) and allow it to be vacuumed into the path of the defoaming solution. This elongated nozzle 14 is quite similar to conventional elongated vacuum nozzles, except that it only has a squeegee surface on three sides—the two short sides 70 , 72 and one long side 74 (the side closest to the vacuum hose 16 ).
As the SDF enters the suction hose 16 it is sprayed with this defoaming solution by two (2) nozzles 22 , 24 oriented at approximately 120° with respect to the direction of flow of the foam being collected. The mixture continues up the suction hose 16 in constant contact with one another and is again sprayed with defoaming solution as it enters the holding tank 18 . The 120° orientation is against the direction of flow of the foam entering the holding tank to encourage mixing. The foam head in the holding tank 18 is also constantly sprayed with defoaming solution to further increase the defoaming rate.
The Defoaming Chemical:
Any defoaming agent can be used with the mechanical system of the described invention. The defoamer, in order to break the foaming capability of the originally dispensed foam, must simply have a lower surface tension than the surfactant used to generate the foam in the first place. This will provide the desired thinning and collapse of the lamella.
Possible chemical structures for defoamers are molecules with a low surface tension, such as silicone, mineral oils, fatty acids and fluorocarbons. The mechanical system of this invention provides the search stress to the solution in order to ensure the distribution of the chosen chemical defoamer.
The system is also designed to provide a means for the defoamer chemical to be recycled in order to continually provide contact to the foam that is being extracted. This improves the mechanical mixing, the contact between the defoaming chemicals and the foam, and minimizes the use of defoaming chemicals in this application for maximum cost effectiveness. Therefore, the ratio of defoamer to surfactant should be great enough to provide defoaming capability to the complete liquid volume of the holding tank. If these parameters are simply unknown to the end user (e.g. surface tension values, total volume), the system at any time can be stopped and more chemical defoamer can simply be added to the holding tank 18 . This does not in any way jeopardize the application.
It should be noted however, that although the type of defoamer is not a critical component, care should be taken to ensure that a non-hazardous chemical solution is chosen in order to ensure the safety of the operator. Several non-toxic, biodegradable and environmentally friendly defoamers are available on the market to choose from. The selection of a suitable defoaming solution would be clear to one skilled in the art.
All citations are hereby incorporated by reference.
The present invention has been described with regard to one or more embodiments. However, it will be apparent to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as defined in the claims.
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Defoaming equipment, and more particularly, removing, defoaming, and storing large amounts of foam after a Blast Mitigation or Decontamination Foam has been used in either an open area or in an contained area is described. An apparatus is provided for defoaming, comprising: a vacuum system, including a vacuum head for drawing the foam through a suction hose terminating in a nozzle, that feeds the foam into a holding tank that initially stores a quantity of defoaming agent, and a pump drawing the defoaming agent from the holding tank to at least one injector that is fitted on the vacuum-side of the vacuum system, whereby the defoaming agent is actively mixed with the collected foam, reducing the collected foam. The reduced foam and defoaming agent are recirculated through the pump and the nozzle, the suction hose, the vacuum system, the injector and holding tank are of chemical-resistant construction.
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FIELD OF THE INVENTION
This invention relates to a floating screed asphalt paver, and more particularly, relates to a floating screed paver having a floating screed and an auger/cut off assembly. The auger/cut off assembly includes an auger mechanism for distributing asphalt paving material evenly in front of the floating screed and a cut off mechanism for cutting off the flow of paving material to the floating screed when the cut off mechanism is in a closed cut off position and for striking off the paving material in front of the floating screed when the cut off mechanism is in an open strike off position.
BACKGROUND OF THE INVENTION
Most asphalt pavers employ a floating screed in which asphalt paving material is distributed in front of the floating screed as the paver moves along the roadbed to be paved. Particularly, such a conventional floating screed paver consists of a self-propelled power unit, a floating screed connected at the rear end of the power unit, a hopper at the forward end of the power unit for receiving paving material from a dump truck, a gravity feed hopper or a conveyor system for moving the paving material from the hopper to the roadbed in front of the floating screed, an auger assembly between the conveyor system and the floating screed for evenly distributing the paving material across the width of the floating screed, and a fixed strike off plate between the auger and the floating screed to control buildup of paving material in front of the floating screed.
The self-propelled power unit is typically mounted on tracks or rubber tires. The self-propelled power unit thereby provides the motive force for the paver along the roadbed as well as power for the operation and control of the various paving functions of the paver including functions associated with the hopper, the conveyor system, the auger, and the floating screed.
The hopper, mounted at the front end of the power unit, contacts the dump truck, and the power unit of the paver pushes the dump truck along the roadbed as the dump truck progressively dumps its load of paving material into the hopper.
The conveyor system on the paver or gravity moves the paving material from the hopper for discharge onto the roadbed. The screw auger spreads the paving material in front of and across the width of the floating screed. The fixed strike off plate controls the buildup of paving material in front of the floating screed.
The floating screed is commonly connected to the power unit by pivoting tow or draft arms, which allow the screed to float on the paving material. The depth of the paving material is controlled by a depth screw at each end of the screed. The screed functions to level, compact, and set the width of the paving material thereby leaving the finished asphalt slab with a uniform and smooth surface.
At the end of a paving pass with a conventional floating screed paver, the loose paving material that has been discharged by the conveyor system to the auger in front of the floating screed will remain on the roadbed and must be removed with a shovel by hand. In order to eliminate the labor involved in such a cleanup, prior art floating screed pavers have employed a cut off gate comprising a hinged cut off plate located in front of and below the auger. When the conventional cut off plate was activated by a hydraulic cylinder, the cut off plate would swing rearwardly into contact with the fixed strike off plate to eliminate the discharge of loose paving material onto the roadbed below the auger. The swinging cut off plate below the auger required additional ground clearance for its operation and thereby restricted how low the auger could be positioned.
In order for the auger to be lowered with minimum ground clearance, there is a need for a paving material cut off mechanism that does not require additional ground clearance. Moreover, there is a need for a cut off mechanism that is adjustable to varied the degree of strike off of paving material ahead of the floating screed and that can eliminate the deposit of loose paving material at the end of a paving pass.
In addition, there is a need for a auger/cut off assembly which may be divided into sections across the width of the paver. The auger sections can be independently operated, and the cut off mechanism sections can be independently opened and closed to control of the feed of paving material to the floating screed in discrete sections across the width of the floating screed.
SUMMARY OF THE INVENTION
The present invention satisfies the above-described need for an improved auger/cut off assembly by providing an auger/cut off assembly consisting of an auger mechanism and a cut off mechanism. The auger mechanism consists of a auger support member for supporting an auger for rotation about an axis. The cut off mechanism consists of at least one concave cut off panel that is rotated by means of an actuator about the axis of the auger between an open strike off position and a closed cut off position. Because the concave cut off panel closely conforms to a portion of the circumference of the auger, the auger/cut off assembly allows low ground clearance.
With the concave cut off panel in the open strike off position, the bottom of the auger is exposed so that the paving material can be discharged from the auger onto the roadbed. In addition, when the cut off panel is in the open strike off position, the leading edge of the concave cut off panel functions as a strike off edge. Moreover, because the cut off panel can be rotated between the open strike off position and the closed cut off position, the degree of engagement of the strike off edge can be continuously varied by the actuator to insure that the proper amount of paving material is removed by the strike off edge of the concave cut off panel.
In the closed cut off position, the concave cut off panel forms a trough beneath the auger to catch the loose paving material so that the loose paving material is not deposit on the roadbed at the end of a paving pass. Because the ends of the concave cut off panel are open, the loose paving material can be moved along the trough formed by the concave cut off panel and discharged through the open ends outboard of the floating screed paver for filling potholes or trenches for example.
Consequently, the concave cut off panel performs the dual function of striking off the paving material when the concave cut off panel is in the open strike off position and cutting off discharge of the paving material in front of the floating screed when the concave cut off panel is in the closed cut off position. In one embodiment of the invention, the auger/cut off assembly comprises a single auger mechanism and a single cut off mechanism. In another embodiment of the invention, the auger cut off assembly comprises a plurality of auger mechanisms and a plurality of cut off mechanisms. Particularly, in one embodiment, the concave cut off panel comprises two independently controlled concave cut off panels, and the auger comprises two independently controlled augers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a floating screed asphalt paver in accordance with the present invention.
FIG. 2 is a top plan view of a floating screed asphalt paver in accordance with the present invention.
FIG. 3 is a rear perspective view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in an open strike off position.
FIG. 4 is a rear perspective view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in a partially closed cut off position.
FIG. 5 is a side elevation view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in the open strike off position.
FIG. 6 is a side elevation view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in the closed cut off position.
FIG. 7 is a front elevation view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in the partially closed cut off position.
FIG. 8 is a rear perspective view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with one section of the cut off mechanism in a closed cut off position and a second section of the cut off mechanism in the open strike off position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is an auger/cut off assembly for a floating screed paver. The auger/cut off assembly comprises an auger mechanism and a cut off mechanism. The auger mechanism consists of an auger support member attached to the floating screed paver which supports an auger for rotation about an axis. The cut off mechanism consists of at least one concave cut off panel that is rotated by means of an actuator about the axis of the auger between an open strike off position and a closed cut off position. In one embodiment, the auger mechanism consists of two independently controlled augers, and the cut off mechanism consists of two concave cut off panels that are independently rotated by means of independent actuators about the axis of the augers between an open strike off position and a closed cut off position.
Turning to the figures, FIG. 1 is a side elevation view of a floating screed asphalt paver 10 in accordance with the present invention. The floating screed paver 10 is designed to lay a finished slab of asphalt on a roadbed 12 . In connection with the following description of the floating screed paver 10 , references to “left” and “right” will be from the perspective of an operator at the rear of the paver 10 facing forward. Consequently, the elements shown in FIG. 1 are the left hand elements of the paver 10 . By contrast in FIG. 7 , the left side of the drawing represents the right hand side of the paver 10 and vice versa. With further reference to FIG. 1 , the floating screed paver 10 comprises a self-propelled power unit 14 , an operator deck 20 , a hopper 24 with a left wing 26 and a right wing 28 , a floating screed 30 , an asphalt material conveyor system 52 , and an auger/cut off assembly 58 .
The self propelled power unit 14 includes a frame 15 , a motor 16 , generally a diesel engine, a hydraulic system (not shown), and crawler tracks 18 . The motor 16 provides the prime motive power for the self propelled power unit 14 . Typically, the motor 16 drives a hydraulic pump (not shown) which in turn drives hydraulic motors and cylinders to power the various functions of the floating screed paver 10 . For example, a pair of hydraulic motors (not shown) propel the paver 10 along the roadbed 12 on the crawler tracks 18 . In other embodiments of the paver 10 , rubber tires may be used instead of the crawler tracks 18 .
The floating screed paver 10 is controlled by an operator from the operator deck 20 by means of a control panel 22 .
The hopper 24 receives asphalt paving material from a dump truck (not shown) at the front end of the paver 10 . The wings 26 and 28 are controlled by means of hydraulic cylinders (not shown) to open in order to expand the width of the hopper 24 in order to receive paving material and to close in order to minimize the width of the hopper during transportation and maneuvering.
As shown in FIG. 2 , the conveyor system 52 along the bottom of the hopper 24 delivers the paving material from the hopper 24 to the roadbed 12 in front of the floating screed 30 . The conveyor system 52 is divided in half across the width of the hopper and consists of a left conveyor 54 and a right conveyor 56 . Each conveyor 54 and 56 consists of the series of slats mounted at each end on a continuous chain. Each conveyor 54 and 56 is independently driven by a hydraulic motor to control the amount of paving material delivered to each half of the roadbed 12 in front of the floating screed 30 . The conveyor system 52 could also consist of a single conveyor instead of the left conveyor 54 and the right conveyor 56 . Alternatively, the conveyor system 52 could also consist of multiple conveyors extending across the width of the hopper 24 . Moreover, the conveyor system 52 may comprise a gravity feed from the hopper.
The floating screed 30 is attached to the power unit 14 by means of a left draft arm 40 , a right draft arm 42 , a left pivot pin 32 , and a right pivot pin 34 so that the floating screed 30 is pulled by the power unit 14 along the roadbed 12 . The floating screed 30 is raised for transportation by means of hydraulic cylinders such as left side hydraulic cylinder 36 . The floating screed 30 is supported on a left side skid 48 and on a right side skid 50 which contact the roadbed 12 when the paver 10 is not involved in a paving operation. During a paving operation, the relative height of the floating screed 30 with respect to the roadbed 12 , and therefore the thickness of the finished slab, is controlled by a left side depth screw 44 and a right side depth screw 46 . Particularly, the left side depth screw 44 and the right side depth screw 46 very the angle of attack of the floating screed 30 on each end of the floating screed 30 .
In order to insure proper operation of the floating screed 30 , the auger/cut off assembly 58 includes an auger mechanism 59 and a cut off mechanism 104 . The auger mechanism 59 receives the paving material from the conveyor system 52 and distributes the paving material evenly across the width of the floating screed 30 including any screed extensions for producing wider paving widths. The cut off mechanism 104 has an open strike off position ( FIGS. 3 and 5 ) and a closed cut off position (FIGS. 4 and 6 ). In the open strike off position, the cut off mechanism 104 strikes off the paving material in order to control buildup of the paving material in front of the floating screed 30 . In the closed cut off position, the cut off mechanism cuts off the flow of paving material from the conveyor system 52 to the roadbed 12 in front of the floating screed 30 thereby eliminating the deposit of loose paving material on the roadbed 12 at the end of a paving pass.
Turning to FIGS. 3 and 5 , the auger/cut off assembly 58 is shown in the open strike off position. As previously stated, the auger/cut off assembly 58 consists of the auger mechanism 59 and the cut off mechanism 104 . With reference to FIG. 7 , the auger mechanism 59 consists of an auger support member 60 and a left auger 80 and a right auger 90 . The auger support member 60 has a left mounting bracket 62 and a right mounting bracket 64 for mounting the auger support member 60 to the self-propelled power unit 14 between the outlet of the conveyor system 52 and the floating screed 30 . Auger bearing supports 66 , 68 , and 70 extended below the auger support member 60 and carry auger bearings 72 , 74 , 76 , and 78 . The left auger 80 is journaled for rotation in auger bearings 72 and 74 , and the right auger 90 is journaled for rotation in auger bearings 76 and 78 . The left auger 80 and the right auger 90 both rotate about a common auger axis of rotation 100 . The left auger 80 is driven by a left hydraulic motor 82 by means of a left motor sprocket 84 , a left auger sprocket 86 , and a left drive chain 88 . Likewise, the right auger 90 is driven by a right hydraulic motor 92 by means of a right motor sprocket 94 , a right auger sprocket 96 , and a right drive chain 98 . Each of the hydraulic motors 82 and 92 are independently controllable in the forward or reverse direction by the operator from the controlled panel 22 . Also, the speed of each of the hydraulic motors 82 and 92 is independently controlled by the operator from the control panel 22 . Consequently, the augers 80 and 90 can be independently controlled to move paving material at different and variable rates from the center outward, from the sides inward, to the left, or to the right.
With reference to FIG. 3 , the auger support member 60 is hollow with a series of inlet vents 65 along the length of the bottom of the support member 60 and outlets vents 67 along the front of the support member 60 . A source of vacuum (not shown) is attached to outlets vents 67 in order to draw fumes from the paving material into inlet vents 67 and away from of paving material in close proximity with the operator of the paver. In that way, the fumes can be collected and processed before being released to the atmosphere away from the operator of the paver.
The cut off mechanism 104 of the auger/cut off assembly 58 consists of a left concave cut off panel 106 and a right concave cut off panel 118 . As can best be seen in FIG. 4 , the left concave cut off panel 106 has a partial hub 108 attached at one end and a partial hub 110 attached at the other end. Likewise, the left concave cut off panel 118 has a partial hub 120 attached at one end and a partial hub 122 attached at the other end. The partial hubs 108 , 110 , 120 , and 122 are all journaled for rotation about the augers axis of rotation 100 . The partial hubs 108 and 122 at the end of each of the concave cut off panels 106 and 118 are open. The concave cut off panels 106 and 118 have a circumference that closely matches of the circumference of the augers 80 and 90 . In addition and as shown in FIG. 7 , the left concave cut off panel 106 has a left strike off edge 112 . Likewise, the right concave cut off panel 118 has a right strike off edge 124 .
The rotation of the left cut off panel 106 about the axis of rotation 100 is independently controlled by a left actuator which includes a hydraulic cylinder 114 connected between a left upper bracket 115 and a left lower bracket 117 . Likewise, the rotation of the right cut off panel 118 about the axis of rotation 100 is independently controlled by a right actuator which includes a hydraulic cylinder 126 connected between a right upper bracket 127 and a right lower bracket 129 . The upper brackets 115 and 127 are fixed to the support member 60 and the lower brackets 117 and 129 are connected to the left concave cut off panel 106 and the right concave cut off panel 118 respectively.
FIGS. 3 and 5 illustrate the open strike off position of the cut off mechanism 59 , and FIGS. 4 and 6 illustrate the closed cut off position of the cut off mechanism 59 . During the continuous paving operation, the concave cut off panels 106 and 118 are rotated by means of the hydraulic cylinders 114 and 126 to the open strike off position shown in FIGS. 3 and 5 . In the open strike off position, the strike off edges 112 and 124 of the concave cut off panels 106 and 118 strike off the paving material delivered from the conveyors 54 and 56 to the augers 80 and 90 . The depth of engagement of the strike off edges 112 and 124 can be varied by extending and retracting the hydraulic cylinders 114 and 126 thereby allowing more or less paving material to reach the leading edge of the floating screed 30 .
Once the paver reaches the end of paving run, the hydraulic cylinders 114 and 126 are extended so that the concave cut off panels 106 and 118 rotate to the fully closed cut off position shown in FIG. 6 . If paving material remains in the augers 80 and 90 at the time the concave cut off panels 106 and 118 are move to the closed cut off position, the augers 80 and 90 may continue to run thereby delivering the paving material to the outside ends of the concave cut off panels 106 and 118 . Because the partial end hubs 108 and 122 are open, the paving material is carried along the concave cut off panels 106 and 118 by the augers 80 and 90 , and the paving material is thus expelled from the concave cut off panels 106 and 118 on either side of the paver 10 . In that manner, loose paving material is not left on the roadbed 12 at the end of the finished slap at the end of the paving run. Any excess material is either carried in the concave cut off panels 106 and 118 or is extruded out of the ends of the cut off panels 106 and 118 to the side of the slab and out of the way. By extruded paving material out of the ends of the cut off panels 106 and 118 , the paver can be used to deliver paving material to potholes or trenches along the side of the paver.
Because the concave cut off panels 106 and 118 are closely fit to the diameter of the augers 80 and 90 and because the concave cut off panels 106 and 118 rotate about the augers' axis of rotation 100 , the concave cut off panels 106 and 118 extend below the augers 80 and 90 only by the thickness of the concave cut off panels 106 and 118 themselves. Consequently, the configuration of the concave cut off panels 106 and 118 and their rotation about the augers' axis of rotation 100 allows the augers 80 and 90 to be position close to the roadbed 12 .
FIG. 8 illustrates the auger/cut off assembly 58 with the left cut off panel 106 in the closed cut off position and the right cut off panel 118 in the open strike off position. With the cut off panels 106 and 118 independently position by the actuators 114 and 126 as shown in FIG. 8 , the paver 10 can be used to pave a strip that is half the width of the paver.
The present invention thus contemplates an auger/cut off assembly with a single auger and single cut off panel, an auger/cut off assembly with two independently controlled augers (such as augers 80 and 90 ) and two independently controlled cut off panels (such as cut off panels 106 and 118 ), and an auger/cut off assembly with multiple independently controlled augers and multiple independently controlled cut off panels.
Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description.
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An auger/cut off assembly for a floating screed asphalt paver. The auger/cut off assembly consists of an auger mechanism with an axis of rotation and a cut off mechanism. The cut off mechanism has a concave cut off panel that rotates about the axis of the auger mechanism from an open strike off position to a closed cut off position. Because the concave cut off panel closely conforms to a portion of the circumference of the auger mechanism, the cut off mechanism provides for low ground clearance. The concave cut off panel serves the dual function of striking off the paving material when in the open strike off position and cutting off the deposit of paving material when in the closed cut off position.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a brake lever, and more particularly to a hydraulic brake lever using a flexible separator to hold hydraulic oil in a front section of the hydraulic brake lever.
2. Description of the Related Art
Because a hydraulic brake system has a high brake force and can provide safe and stable brake effects, the hydraulic brake system is often used on high priced bicycles. A conventional hydraulic brake system comprises a brake lever mounted on a handlebar of a bicycle, a disc brake mounted beside a wheel of the bicycle and a hydraulic tube connected to the brake lever and the disc brake.
A conventional brake lever comprises a body have a cavity and an oil chamber for accommodating a piston set and hydraulic oil. Because the brake lever will apply a high pressure on the hydraulic oil when braking, the body must be manufactured by forging to prevent the body from breaking or leaking. Thus, manufacturing the conventional brake lever is complicated and time-consuming and a manufacturing cost is expensive and cannot satisfy the demands of the bicycle industry and consumers.
To overcome the shortcomings, the present invention provides a hydraulic brake lever to mitigate or obviate the aforementioned problems.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide a hydraulic brake lever using a flexible separator to hold the hydraulic oil in a front section of the hydraulic brake lever.
A hydraulic brake lever in accordance with the present invention comprises a body having a bladder chamber, a cavity and a flexible separator mounted between the bladder chamber and the cavity. The flexible separator holds the hydraulic oil in the front section of the body and prevents a rear section of the body from contacting with the pressurized hydraulic oil. A cylinder is mounted in the cavity of the body and accommodates a piston set. Thus, a high pressure is kept in the cylinder and is not applied directly on the body. Due to the separating design, the hydraulic oil applied a low pressure on the body. Thus, manufacturing the body is less limited and a manufacturing cost is reduced.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a hydraulic brake lever in accordance with the present invention;
FIG. 2 is an exploded perspective view of the hydraulic brake lever in FIG. 1 ;
FIG. 3 is a top view in partial cross section of the hydraulic brake lever in FIG. 1 ;
FIG. 4 is an enlarged top view in partial cross section of the hydraulic brake lever in FIG. 1 ; and
FIG. 5 is an operational enlarged top view in partial cross section of the hydraulic brake lever in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1 to 3 , a hydraulic brake lever in accordance with the present invention comprises a body (A), a lever bar ( 20 ), a cylinder ( 40 ), a piston set ( 50 ), a cover ( 60 ) and a hydraulic tube ( 70 ).
The body (A) has a front section and a rear section, may be formed integrally as one piece and may comprise a base member ( 10 ), a flexible separator ( 33 ) and a cavity member ( 30 ). The base member ( 10 ) may be manufactured as one piece by die-casting and is disposed in the rear section of the body (A). The base member ( 10 ) has a front end, a rear end, two sides, a connecting section ( 11 ), a mounting groove ( 12 ), a pivoting hole ( 13 ), an abutting section ( 14 ), a receiving chamber ( 15 ), a rod hole ( 16 ) and a bladder chamber ( 17 ). The connecting section ( 11 ) is formed in one of the sides of the base member ( 10 ) and may be mounted on a handle bar of a bicycle. The mounting groove ( 12 ) is formed in the other side of the base member ( 10 ). The pivoting hole ( 13 ) is defined through the base member ( 10 ) and communicates with the mounting groove ( 12 ). The abutting section ( 14 ) is formed on the front end of the base member ( 10 ), is disposed between the sides of the base member ( 10 ) and has an end face ( 141 ) and a shoulder ( 142 ). The end face ( 141 ) is formed in the front end of the base member ( 10 ). The shoulder ( 142 ) is formed in the front end of the base member ( 10 ) and is disposed beside the end face ( 141 ) of the abutting section ( 14 ). The receiving chamber ( 15 ) is defined in the front end of the base member ( 10 ), is disposed in the end face ( 141 ) of the abutting section ( 14 ) and has a bottom and an inner thread. The rod hole ( 16 ) is defined through the bottom of the receiving chamber ( 15 ) along coaxially the receiving chamber ( 15 ) and communicates with the mounting groove ( 12 ). The bladder chamber ( 17 ) is defined in the front end of the base member ( 10 ), is disposed beside the receiving chamber ( 15 ) and may be substantially rectangular.
The flexible separator ( 33 ) may be made of flexible materials such as rubber or silicone. The flexible separator ( 33 ) abuts the end face ( 141 ) of the abutting section ( 14 ) and has an edge, a sealing flange ( 331 ), a through hole ( 332 ) and a bladder ( 333 ). The sealing flange ( 331 ) is formed along the edge of the flexible separator ( 33 ) and extends around the receiving and bladder chambers ( 15 , 17 ). The through hole ( 332 ) is defined through the flexible separator ( 33 ) and corresponds to the receiving chamber ( 15 ). The bladder ( 333 ) is formed integrally on the flexible separator ( 33 ) and is mounted in and spaced from the bladder chamber ( 17 ) of the base member ( 10 ) so the bladder ( 333 ) can expand in the bladder chamber ( 17 ) and is used for receiving hydraulic oil.
The cavity member ( 30 ) is disposed in the front section of the body (A) and may be manufactured as one piece by forging. The cavity member ( 30 ) abuts the flexible separator ( 33 ) and has a front end, a rear end, an outer surface, a cavity ( 31 ), a connecting section ( 32 ), a connecting hole ( 34 ) and an oil hole ( 35 ). The cavity ( 31 ) is defined in the rear end of the cavity member ( 31 ) and communicates with the bladder ( 333 ) of the flexible separator ( 33 ). The connecting section ( 32 ) is formed on the rear end of the cavity member ( 30 ) around the cavity ( 31 ), engages the abutting section ( 14 ) of the base member ( 10 ) and abuts the sealing flange ( 331 ) of the flexible separator ( 33 ) so the cavity ( 31 ) is sealed by the sealing flange ( 331 ). The connecting hole ( 34 ) is defined through the front end of the cavity member ( 30 ) and communicates with the cavity ( 31 ). The oil hole ( 35 ) is defined through the outer surface of the cavity member ( 30 ) and communicates with the cavity ( 31 ). The oil hole ( 35 ) may be threaded and may be closed by a threaded plug ( 36 ).
The lever bar ( 20 ) is mounted pivotally on the base member ( 10 ) of the body (A) and has a pivot ( 21 ), a drive section ( 22 ), a bar section ( 23 ), a drive member ( 24 ) and a sleeve ( 25 ). The pivot ( 21 ) is mounted in the pivoting hole ( 13 ) of the base member ( 10 ). The drive section ( 22 ) is mounted in the mounting groove ( 12 ) of the base member ( 10 ) and is connected to the pivot ( 21 ). The bar section ( 23 ) is connected to the drive section ( 22 ) and protrudes from the base member ( 10 ). The drive member ( 24 ) is mounted in the drive section ( 2 ) and has a threaded bore aligned with the rod hole ( 16 ). The sleeve ( 25 ) is mounted between the drive member ( 24 ) and the drive section ( 22 ) to allow the drive member ( 24 ) to move with good flexibility.
With further reference to FIG. 4 , the cylinder ( 40 ) is cylindrical and is mounted in the cavity ( 31 ) of the cavity member ( 30 ). The cylinder ( 40 ) has a front end, a rear end, an outer surface, a cylinder chamber ( 41 ), a cylinder head ( 42 ), a threaded section ( 43 ), an abutting flange ( 44 ), a washer ( 45 ), a guide hole ( 46 ), a lead hole ( 47 ), a mounting flange ( 48 ) and a sealing ring ( 49 ). The cylinder chamber ( 41 ) is defined longitudinally in the rear end of the cylinder ( 40 ) and communicates with the rod hole ( 16 ) of the base member ( 10 ). The cylinder head ( 42 ) is formed on the front end of the cylinder ( 40 ), protrudes from the front end of the cavity member ( 30 ) and has an outer thread and a flow channel ( 421 ). The flow channel ( 421 ) is defined through the cylinder head ( 42 ) and communicates with the cylinder chamber ( 41 ). The threaded section ( 43 ) is formed on the rear end of the cylinder ( 40 ), extends through the through hole ( 332 ) of the flexible separator ( 33 ) and is screwed into the receiving chamber ( 15 ) of the base member ( 10 ). The abutting flange ( 44 ) is formed around the cylinder ( 40 ) near the rear end and clamps the flexible separator ( 33 ). The washer ( 45 ) is mounted between the abutting flange ( 44 ) and the flexible separator ( 33 ) to increase a sealing effect and prevent the flexible separator ( 33 ) from being damaged when screwing the cylinder ( 40 ) into the receiving chamber ( 15 ). The guide and lead holes ( 46 , 47 ) are defined through the outer surface of the cylinder ( 40 ) and communicate the cylinder chamber ( 41 ) with the cavity ( 31 ). The mounting flange ( 48 ) is formed around the cylinder ( 40 ) near the front end and faces the rear end of the cavity member ( 30 ). The sealing ring ( 49 ) is mounted between the mounting flange ( 48 ) and the rear end of the cavity member ( 30 ) to provide a sealing effect.
The piston set ( 50 ) is mounted in the cylinder ( 40 ) and comprises a piston ( 51 ), a push rod ( 52 ) and a spring ( 53 ). The piston ( 51 ) is mounted movably in and spaced from the cylinder chamber ( 41 ) of the cylinder ( 40 ) and faces the lead hole ( 47 ) of the cylinder ( 40 ) so as to allow the hydraulic oil to be filled between the piston ( 51 ) and the cylinder ( 40 ) through the lead hole ( 47 ). Thus, the piston ( 51 ) can move smoothly in the cylinder chamber ( 41 ). The piston ( 51 ) has a front end, a rear end, an annular groove ( 511 ), a sealing ring ( 512 ), a shaft ( 513 ), an end cap ( 514 ) and an oil-stopping ring ( 515 ). The annular groove ( 511 ) is formed in the rear end of the piston ( 51 ). The sealing ring ( 512 ) is mounted in the annular groove ( 511 ) and is mounted between the piston ( 51 ) and the cylinder ( 40 ). The shaft ( 513 ) is formed coaxially on the front end of the piston ( 51 ). The end cap ( 514 ) is mounted on the shaft ( 513 ). The oil-stopping ring ( 515 ) is mounted around the shaft ( 513 ), is disposed between the end cap ( 514 ) and the piston ( 51 ) and may have a front face and an annular groove defined in the front face. The push rod ( 52 ) is connected to the rear end of the piston ( 51 ), extends through the receiving chamber ( 15 ) and the rod hole ( 16 ) of the base member ( 10 ) and is screwed into the threaded bore of the drive member ( 24 ) of the lever bar ( 20 ). Thus, the lever bar ( 20 ) can drive the push rod ( 52 ) to move by forcing the drive member ( 24 ). The spring ( 53 ) is mounted in the cylinder chamber ( 41 ) between the piston ( 51 ) and the front end of the cylinder ( 40 ) to provide the piston ( 51 ) with a returning force.
The cover ( 60 ) is mounted on the front ends of the cavity member ( 30 ) and the cylinder ( 40 ) and has a positioning nut ( 61 ). The positioning nut ( 61 ) is screwed on the cylinder head ( 42 ) of the cylinder ( 40 ) to position the cavity member ( 30 ) between the cover head ( 60 ) and the base member ( 10 ).
The hydraulic tube ( 70 ) communicates with the flow channel ( 421 ) of the cylinder head ( 42 ) and is connected to a disc brake of a disc brake system. Thus, the lever bar ( 20 ) can drive the disc brake through the hydraulic tube ( 70 ).
With reference to FIGS. 3 and 5 , when the hydraulic brake lever is in use, the hydraulic oil is filled into the cavity ( 31 ) of the cavity member ( 30 ) and the cylinder chamber ( 41 ) of the cylinder ( 40 ) with an oil storage capacity of the bladder ( 333 ) of the flexible separator ( 33 ). When a user pulls the bar section ( 23 ) of the lever bar ( 20 ), the lever bar ( 20 ) drive the push rod ( 42 ) to move the piston ( 51 ) forwards through the drive member ( 24 ). The piston ( 51 ) presses the hydraulic oil to pass through the hydraulic tube ( 70 ) and actuate the disc brake of the disc brake system to provide a braking effect. When the user releases the bar section ( 23 ) of the lever bar ( 20 ), the spring ( 53 ) of the piston set ( 50 ) pushes components of the hydraulic brake lever back to their original positions.
With reference to FIGS. 3 and 4 , the hydraulic brake lever uses the flexible separator ( 33 ) to prevent the pressurized hydraulic oil from contacting directly with the base member ( 10 ). Thus, the base member ( 10 ) can be manufactured by simple, fast and cheap processes such as die-casting. Additionally, due to the structure design of the cylinder ( 40 ), a pressure applying on the cavity member ( 30 ) is lower than that on the cylinder ( 40 ). Therefore, manufacturing the cavity member ( 30 ) is less limited and a manufacturing cost is also reduced.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A hydraulic brake lever includes a body having a bladder chamber, a cavity and a flexible separator mounted between the bladder chamber and the cavity. The flexible separator holds hydraulic oil in a front section of the body and prevents a rear section of the body from contacting with the pressurized hydraulic oil. A cylinder is mounted in the cavity of the body and accommodates a piston set. Thus, a high pressure is kept in the cylinder and is not applied directly on the body. Due to the separating design, the hydraulic oil applied a low pressure on the body. Thus, manufacturing the body is less limited and a manufacturing cost is reduced.
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THE SEVERAL VIEWS OF DRAWINGS
[0001] Included within this application are 23 figured drawings, ranging from basic ornamental elements, to full fence panels. Application of ornamental elements to existing fence panels and other architectural applications are shown, as well as the apparatus of manufacture. These shall serve to illustrate the following description
DESCRIPTION
[0002] The invention consists of arrangements of conveyor hooks and their derivatives, in such a manner to produce welded modular ornamental elements, incorporated into rigid frames for fence panels ( FIGS. 1, 2 , 3 , 4 , 5 ,), individual modules for existing wood panel fencing décor elements ( FIGS. 6 , and 6 a ), and other architectural and structural elements ( FIG. 6 b ).
[0003] A conveyor hook for purpose of the invention's description is, but not limited to, a wire hook, typically used as a parts carrying apparatus for paint finishing conveyor lines. Generally these hooks are an eye hook with an u-hook at the other end ( FIG. 7 ). The eye of the hook being larger than the U end, but not limited to, a ratio of 3 to 1. the eye of the hook is, but not limited to, a round, to tear drop loop, with the end of the eye bend pointing to the same side of the hook's shaft as the direction of the u bend ( FIG. 7 ). The end of the eye loop can be touching the shaft (closed), or spaced the thickness of the shaft, or more (open, FIG. 7 ). If a line was drawn, extended from the shaft through the eye, the eye would be bisected, lying on either side of the line. The diameter of the wire hook is principally, but not limited to, 5/16ths of an inch. Lengths of the hooks are principally, but not limited to 9 in., 14 in., and 21 in. The material used is principally, but not limited to, straightened steel coil wire formed to shape. Other materials, such as aluminum, stainless steel, copper, and other shapes, or cross sections of wire, such as twisted hexagon, twisted square, diamond, plain hexagonal, and square, may be employed, but would generally be optional, by request.
[0004] The derivatives of the conveyor hook are subtle changes, and adjustments to the eye, u-bend ends, and shafts of the hook. The lengths are nominally the same as the originals. The following are exemplary, but not limited to, 1. The end of the eye loop no longer points to the shaft, but has a return bend from the former end of the eye loop, to a length able to connect to the shaft of the next hook in the sequence, resembling a mini shepherd's hook with an u-bend at the other end ( FIG. 8 ). The end of the eye loop, and the shepherd's hook direction, is reversed, pointing to the opposite side of the shaft as the u bend direction ( FIG. 8 a ). The u-bend end changes, a bend over to the shaft ( FIG. 9 b ). 3. a small eye ( FIG. 9 c ), with the same but not limited to proportions of 3 to 1, the eye would be bisected by a line from the shaft.
[0005] The shaft variations are, but not limited to, a v slot pointing to the side of the shaft of the u bend direction on the shortest, two on the intermediate size, three on the upper size ( FIG. 10 ), wavy, bent at various tangents along the shaft These shaft variations are generally most useful only near the eye's half of the shaft. Not all of these variations are shown, but are self descriptive.
[0006] These derivatives are combined, but not limited to, having three lengths of shepherd and u bend, three lengths of shepherd and bent over u, three lengths of shepherd and small eye ( FIG. 11 ), three lengths of open tear drop and u, three lengths open tear drop and bent over u, three lengths open tear drop and small eye ( FIG. 12 ), three lengths of round and u, three lengths of round and bent u. three lengths of round and small eye. (not shown self explanatory), also three lengths of round and tear drop closed, with u bend, bent over u, and small eye. In the case of shaft variations, there would be a matching series in each of the above combinations. The variations described above are within, but not limited to, 3 to 1 proportions, and lengths, so as to be interchangeable, and add up, but not limited to, 3 lengths of 30 styles of components, not including shaft variables
[0007] Now that the basic parts have been described, it's on to putting them to good use. Since this is welded fence and décor, the layout and welding station apparatus is the foundation of the manufacturing process ( FIG. 14 ). The table consists of simple design and function. Simply put, it is a 2 in. steel angle, 8 ft.×3 ft rectangle, 4 legs with casters, and a lower shelf, topped of with 3 ft.×8 ft.×1¼ in. thick section of bar grating (cat walk) with the cross bars down (up side down). The cross bar side of the grate is not as flat on all axis as the bar side. The parallel features of the bars aid in layout, and the cross rods below aid in vertical square. The thin surface area of bars on end has only 1/9 the surface area of a normal flat topped table thus staying cleaner, cooler, minimal flatness distortion, keeping work product flat. The bar grating also serves as a very clamp friendly surface should the need arise; small panels, frames and the like.
[0008] Now that there is a table, on with production. Because of the proportionality of the ends of the conveyor hook, that of, but not limited to, 3 to 1, they lend themselves to quick layout, producing ornamental element modules, by assembling hooks, but not limited to, 1. Touch at two or more places for welding purposes. 2. Assembling the hooks with the smaller ends at each apex of the u bend, closing the u bend of the previous hook, or inside of the previous, on the same side of the shaft as the direction of the u bend, and the eye touches ( FIG. 15 ). This process carries out to a circle with sharp angles at the u bend ( FIG. 16 ). Element modules from this process are segments of this circle, and appear fan like ( FIGS. 17, 18 ). 3. Assembling hooks side by side, same bend direction ( FIG. 19 , lower portion). This process carries out to a circle with slight angles at the u bend. Element modules from this process are segments of this circle, and appear festoon like ( FIG. 19 lower portion). 4. Mirror image, bend direction meeting. This process combined in pairs carries to a circle with slight angles at the u bend ( FIG. 20 ), and element modules appear festoon like ( FIG. 20 ), but in a different way than ( FIG. 19 ) above. 5. Alternating lengths, and styles, whether singularly or sequenced in any process above. 6. Parallel arrangements, such as eyes at top and bottom, u bends in the center ( FIG. 21 ). Eyes in the center, u bends top and bottom ( FIG. 22 ). Serially, by length, smaller to larger at the bottom, and larger to smaller at the top, eyes diagonal ( FIG. 23 ), The above in series the length of the panel, or as separators for other element combinations.
[0009] Once the chosen elements are selected and laid out, the joining doth commence. Welding is done from, but not limited to; the center of the overall layout, welding all small ends in each module or series, then joining the eyes at their cooperating points. Any distortion from initial welding is more easily adjusted at the eye end of the layout. When all layout welding is complete the welds are hammer tested for integrity.
[0010] Then attach to the chosen frame at the perimeters of the layout, in the case of rigid fence, the frame consists of, but is not limited to, ¾ in×1½ in.×16 gage steel rectangular tube, with the ¾ in. face as perimeter, adding depth to the panel, or the 1½ in. face as perimeter for a streamline, and thin appearance. In either case, the short members of the frame are pre drilled, as well as posts of the same tube and 4 in. square plate for mounting on properly placed footings.
[0011] In the case of décor elements, because of the small sharp angles at the joined points, they are easily mounted on existing wooden fence panel at opposing points of the module, with a few ¾ in. stainless steel screws on each element.
[0012] Once welded, the panels, and, or the décor, are next painted in a three step process, but not limited to, 1. Pretreatment, consisting of soap cleaning, deoxidizing, bonderizing, sealing the metal. 2. e-coat, electro deposition of paint, in a submerged bath, for under coating. 3. Powder paint coating, electro attracted, powder paint coating, oven baked at 400 degrees Fahrenheit, for 20 minutes. Then packed for transport, etc.
[0013] The above described invention encompasses new uses of conveyor hooks, and a new media for ornamental décor elements. The processes are easy, simple to use, enabling quick layout, producing novel ornamentation not found in the many places that have been researched. The Internet, ornamental fence manufacturers, greenhouses, nurseries, home improvement centers, patents, and published patent applications. The field of search was in the classifications of, 256/21, 22, 32, 33, 73, 52/311, 633, 660, 663, 664, 140/93r, and 29. Still through all this none seemed to compare.
[0014] Having described the apparatus, components, methods of manufacture, and articles produced, I seek protection by letters of patent for the following claims.
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The invention is new, useful processes, easily employed in a system of layout and manufacture of welded conveyer hook ornamental fence panel elements, existing wood fence panel ornamental décor elements, and other architectural and structural ornamentation. The system's results are highly ornamental elements of open work, applicable to many uses. The processes are simple, easy to use, efficient, quick, and inexpensive methods of manufacture, producing highly ornate elements cheaply.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to German patent applications DE 10 2009 014 140.5 filed on Mar. 24, 2009 and PCT application PCT/EP2010/001646 filed on Mar. 16, 2010, which are hereby incorporated by reference in their entireties.
TECHNICAL FIELD
[0002] This disclosure relates to a flap arrangement, in particular an exhaust gas flap arrangement.
BACKGROUND
[0003] A flap arrangement as mentioned above is disclosed for instance in DE 37 07 904 A1. Relative to an arrangement with a flap positioned within the exhaust channel and a case-side bearing assembly positioned on one or both sides of the exhaust channel, it provides the development of a bearing assembly used to equalize temperature and manufacturing-related tolerances and deaxations for the shaft supporting the exhaust flap. For this purpose, the bearings of the shaft are rotatably arranged in at least one case-side annular collar protruding laterally relative to the exhaust channel in the direction of the shaft in at least one bearing box guided as a spherical bearing box in one part of the annular collar conically tapered toward the direction of the channel and attached axially spring-mounted in the direction of the exhaust channel. Due to the rotatable and axially displaceable guide of the shaft relative to the bearing box, the design of said bearing assembly requires a certain degree of radial play between the shaft and the cylindrical bore hole of the bearing box retaining the shaft, in particular in view of the working conditions. Said play cannot be equalized with the axial displaceability of the bearing box just as it cannot be equalized by the spherical support for the equalization of distortions and deaxations opposite the tapered part of the annular collar. In particular in connection with exhaust pulsations, this results in movements between the shaft and the bearing box, causing increased wear of the bearing as well as deflection of the bearing assembly.
[0004] An essentially similar situation exists with exhaust flap arrangements as they are disclosed in WO 2008/043429 A1.
SUMMARY
[0005] The object of the invention is to create an additional improved flap arrangement, in particular to design a flap arrangement as mentioned above in such a way that it is well manageable from a manufacturing-related point of view while still achieving satisfactory wear results even with large tolerances.
[0006] This is achieved with a flap arrangement of the kind mentioned above with the characteristics of claim 1 . The subsequent claims describe convenient updated versions.
[0007] The invention of a flap arrangement, in particular an exhaust flap arrangement with pulsating gas flow feed is based on the assumption that the respective gas flap is guided and supported in a case-side bearing assembly by means of a bearing box, which is supported radially flexible, in particular spring-mounted on a predefined radial position. The flexible, in particular spring-mounted bracing of the bearing box on the predefined radial position makes it possible to guide the bearing box “without play,” essentially floating, including under working conditions such as they are present for example for exhaust flaps, because the radially spring-mounted bracing at least in a radial direction achieves a flexibility in the support and guide of the bearing box with which dimensional changes due to the operation can be compensated; either with the bearing box being rotatable relative to the flap or rotating with the flap.
[0008] The radially flexible, in particular spring-mounted support on a predefined radial position is preferably a support on a central target position of the bearing box. According to the invention, this is in particular achieved with an annular collar of the bearing assembly, against which the bearing box is supported and springably braced on the circumference, wherein the annular collar is divided into separate annular sectors in the direction of the circumference, which are at least in part springably abutting radially against the bearing box. Within the scope of the invention, the annular collar can for instance be created with clamping claws originating from a common frame and radially springy form a retaining cage for the bearing box diagonally to their axial extension. Especially complementary, the claws can be pre-clamped to their common central position defined by the stabilized annular sector with a surrounding “spring cuff,” wherein said “cuff” is formed with one or a plurality of annular springs, preferably with a surrounding coil spring.
[0009] The purpose of the invention is in particular also to specify a radial position as target position for the bearing box by means of the annular cuff in such a way that at least one of the annular sectors separated in the circumferential direction which are braced together radially springy forms a radially non-flexible support for the bearing box which the supporting body is positioned on by means of the radially springy and/or spring-mounted braced sectors of the annular cuff.
[0010] In said solution, at least one of the annular sectors of the annular cuff is a stabilized part of the bearing assembly, against which the bearing box is supported by means of other, radially spring-mounted annular sectors. Within the scope of the invention, said spring-mounted braced annular sectors can also be formed with separate elements, which are only kept together by the radially spring-mounted retaining clamping assembly and connected to form the annular cuff with the annular sector stabilized relative to the bearing assembly. In said solution, the annular sector stabilized relative to the bearing assembly forms the radial contact for the bearing box and at the same time the guide base for the other separate annular sectors connected by means of the radial bracing appliance with the annular sector representing the base. As a result, the annular cuff can virtually “breathe,” and bulge to form the base in contrast to the stabilized annular sector within the scope of the required short regulating distances.
[0011] Within the scope of the invention, this is possible for both a cylindrical as well as a spherical contact area between the annular cuff and the bearing box. As a result, not only temperature-related dimensional changes can be equalized, but also manufacturing-related tolerances and axial errors within the corresponding dimensions can be adjusted.
[0012] It is basically within the scope of the invention that the bearing box is created as a single piece in relation to the respective gas flap. In particular with opposite positioning of the gas flap relative to the case of the flap component, the bearing box however preferably forms a rotatable component of the spherical bearing for the flap, in particular gas flap relative to the shaft of the flap. Said spherical bearing preferably comprises a spherical segment and a recess expanding toward the spherical segment and retaining the latter, wherein the spherical segment or the recess is provided on the bearing box. The spherical segment preferably forms an axially protruding part relative to the flap, in particular the gas flap, in the direction of the rotational axis, which is retained in the recess provided in the bearing box, wherein according to the invention the bearing box is axially springy braced opposite the supporting body of the bearing assembly supporting the annular cuff fixed relative to the case. This achieves a guide for the flap, in particular the gas flap that is immune against tolerances and operation-related contamination, said guide advantageously also allowing the arrangement and bracing of the shaft required to adjust the flap.
[0013] The result is a flap arrangement with a simple structure which is insensitive to tolerances and can be designed gas-tight, i.e., is easy to encapsulate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Other details and characteristics of the invention can be gathered from the claims, the description of the drawings and the figures. In the figures:
[0015] FIG. 1 shows a schematic cross-section of an exhaust flap arrangement,
[0016] FIG. 2 shows an insulated and simplified illustration of the case-side bearing assembly in a view according to arrow II in FIG. 1 , and
[0017] FIG. 3 shows a cross-section III-III of the bearing assembly according to FIG. 2 .
DETAILED DESCRIPTION
[0018] In the cross-section of an exhaust flap arrangement 1 illustrated in FIG. 1 , the case surrounding the exhaust channel 2 is labeled with the number 3 . Exhaust channel 2 comprises flap 4 which is rotatable around an axis 5 extending across exhaust channel 2 , routed on both sides of the exhaust channel 2 in the exemplary embodiment. Of the bearing assemblies 6 , 7 provided for this purpose, the bearing assembly 7 is penetrated by the shaft 8 connected with the flap 4 extending toward the direction of the axis 5 . The actuating drive for the flap 4 acts on said shaft in a manner not illustrated here. The shaft 8 penetrates a supporting body 13 in a passage opening 34 , preferably sealed with a seal 35 ( FIG. 2 and FIG. 3 ).
[0019] Said exhaust flap arrangement 1 is preferably provided for use in exhaust systems of motors, in particular diesel motors, used for stationary applications or in motor vehicles, in particular utility vehicles, such as for example as retarding flaps in exhaust brake systems or as reversing flaps in exhaust recycling systems.
[0020] The case 3 comprises concentric annular flanges 10 , 11 relative to the axis 5 for retaining the bearing assemblies 6 , 7 arranged opposite of each other in the direction of the axis 5 and therefore diagonally, in particular perpendicular to the longitudinal axis 9 of the exhaust channel 2 . A lid-like supporting body 12 , 13 of a bearing case is screwed down against said annular flanges on the face, said supporting body being equipped with an annular cuff 14 , 15 , which axially latches in to the respective intake opening 16 , 17 of the annular flange 10 , 11 in the direction of the axis 5 . The respective annular cuff 14 , 15 surrounds the bearing opening 18 , 19 for a bearing box 20 , 21 which has an open recess 22 , 23 in the middle against the exhaust channel 2 . A spherical segment 24 , 25 such as in the shape of a spherical section or a spherical disk connected with the flap 4 latches into said recess. The respective bearing box 20 , 21 is flexibly braced in the direction of said spherical segment 24 , 25 , in particular spring-loaded, wherein said spring load 26 , 27 is created with a disk spring package in the exemplary embodiment.
[0021] In FIG. 1 , only a segmented disk is provided as spherical segment 24 , which is formed in particular with the bulging of the flap 4 around the edges. The correspondingly flattened spherical segment 24 is retained in the truncated cone-shaped recess 22 . On the opposite side, the spherical segment 25 is formed as a spherical section and created by the end part of the shaft 8 allocated to flap 4 and connected to flap 4 . The recess 23 retaining said end part is dome-shaped.
[0022] It is apparent in particular based on FIG. 2 and FIG. 3 that the respective annular collar, as shown for annular collar 15 , is divided into annular sectors, three annular sectors 28 to 30 in the exemplary embodiment, of which the annular sector 28 is stabilized relative to the supporting body 13 as part of the annular collar 15 forming the bearing dish for the bearing box 21 , is in particular formed as one piece together with the supporting body 13 , while the annular sectors 29 , 30 form parts of the bearing dish that are independent of the supporting body 13 , said parts being supportingly and radially interlocked with the annular sector 28 stabilized relative to the supporting body 13 by means of a spring arrangement 31 against the bearing box 21 . Similar to a spring cuff, the spring arrangement 31 comprises the annular sectors 28 to 30 on its outer circumference, wherein the spring arrangement 31 is defined axially relative to the annular cuff 15 in that it is positioned in an annular groove 32 of the annular cuff 15 on the circumference.
[0023] The exemplary embodiment illustrates a design of the spring arrangement 31 as a coil spring 33 , which is axially abutting against the flanks of the annular groove 32 , so that the annular sectors 29 , 30 creating components that are independent and separate from the supporting body 13 of the annular cuff 15 are likewise axially fixed by means of the spring arrangement 31 .
[0024] This design explained with respect to the bearing assembly 7 applies analogously to the bearing assembly 6 . In both cases, the intake opening 16 , 17 provided in the annular flange 10 , 11 also has minor radial play for the respective annular cuff 14 , 15 , which is irrelevant in view of the bracing of the respective bearing box 20 , 21 , because the bearing box 20 , 21 is braced radially play-free compared to the stabilized annular segment 28 relative to the respective supporting body 12 or 13 due to the radial restraint of the loose annular segments 29 , 30 .
[0025] An embodiment according to the invention in which the flap is connected as a single part with at least one of the respective bearing boxes, in particular the bearing box 20 not penetrated by the shaft 8 with respect to the exemplary embodiment, and is consequently not rotatably supported opposite the bearing box 20 , but is in fact rotatable together with the bearing box 20 , for which the retaining annular cuff 14 subsequently forms a bearing dish divided in circumferential direction with its annular sectors, is not illustrated in the figures.
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For a flap assembly, in particular an exhaust gas flap assembly, with the flap mounted on both sides via bearing devices in the housing, the disclosure describes a design in which a bearing body is supported radially against an annular collar of the bearing device and, by way of the annular collar, is held braced in a radially spring-loaded manner in a predefined radial position.
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TECHNICAL FIELD
[0001] The present invention relates generally to wall framing, and more particularly to a prefabricated frame support structure designed to be interposed between two wall sections intersecting one another at approximately a 90° angle.
BACKGROUND OF THE INVENTION
[0002] During construction of residential homes and similar buildings, it is common practice to construct framing assemblies for intersecting walls at the site of the construction. FIGS. 1 and 2 , for example, illustrate conventional designs for framing assemblies interposed between two wall sections adjoining one another at a T-shaped intersection.
[0003] As shown in FIG. 1 , a primary wall A having a lower plate 12 intersects with an intersecting wall B having a lower plate 14 . During construction, a 2×6 backing stud 16 is position on lower plate 12 and provided for corner nailing. Moreover, a 2×4 end stud 18 is then attached to the 2×6 backing stud 16 and positioned on lower plate 14 . The combination of the two studs (i.e., 2×6 backing stud 16 and 2×4 end stud 18 ) forms the frame support for the T-intersection between primary wall A and intersecting wall B.
[0004] As further shown in FIG. 2 , a primary wall A having a lower plate 12 again intersects with an intersecting wall B having a lower plate 14 . In this design, a 2×4 backing stud 20 is positioned during construction on lower plate 12 and a 2×4 end stud 22 is then attached to the 2×6 backing stud 20 and positioned on lower plate 14 . A pair of additional 2×4 studs 24 a and 24 b are secured to the respective sides of backing stud 20 and serve as a means for corner nailing.
[0005] There are numerous disadvantages and drawbacks to these types framing assemblies for T-intersections. First, the basic approaches illustrated in FIGS. 1 and 2 require more material than is necessary to carry the imposed loads. Furthermore, fabrication of these framing assemblies at the construction site is quite inefficient and time consuming. Virgin lumber and scraps are often used to construct these frame assemblies during construction. Consequently, due to the extra material used and the labor required at the construction site, one can expect the total cost of such framing assemblies to be relatively high.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention presents a prefabricated or premanufactured T-intersection frame structure that is designed to overcome the disadvantages and drawbacks of conventional on-site constructed T-intersection framing assemblies. Generally in the design disclosed herein, the present invention provides a support frame for supporting an intersection between a first wall section and a second wall section. The support frame including a first support panel having a top edge and a bottom edge, which are configured to be positioned between respective upper and lower plates of the first wall section. Moreover, the support frame has a pair of second support panels affixed to the first panel, and each second support panel has a top edge and a bottom edge configured to be positioned between respective upper and lower plates of the second wall section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates a conventional design for framing assemblies interposed between two wall sections adjoining one another at a T-shaped intersection.
[0008] FIG. 2 illustrates another conventional design for framing assemblies interposed between two wall sections adjoining one another at a T-shaped intersection.
[0009] FIG. 3 illustrates a perspective of two wall sections connected to one another by the frame structure in accordance with an exemplary embodiment.
[0010] FIG. 4 illustrates a cross-sectional view of the frame structure in accordance with an exemplary embodiment.
[0011] FIG. 5 illustrates a side partial view of the frame structure interposed between the two wall sections in accordance with an exemplary embodiment.
[0012] FIG. 6 illustrates a cross-sectional view of the frame structure in accordance with an exemplary embodiment.
[0013] FIG. 7 illustrates a side partial view of the frame structure interposed between the two wall sections in accordance with another exemplary embodiment.
[0014] FIG. 8 illustrate an advantageous shipping configuration of T-intersection frame structures in accordance with an exemplary embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 3 illustrates a perspective 100 of two wall sections connected to one another by the frame structure in accordance with an exemplary embodiment of the present invention. It should be readily apparent that the two wall sections can represent any intersecting wall sections in any building. In the exemplary embodiment, the intersection is a T-intersection where the pair of wall sections intersect at an approximately 90° angle. Specifically, as shown, frame structure 110 is interposed between first wall section 120 and second wall section 130 . Wall section 120 further includes lower plate 122 , upper plate 124 and a plurality of studs 140 connected between lower plate 122 and upper plate 124 . One skilled in the art would appreciate that the lower and upper plates are typically conventional 2×4 studs or 2×6 studs. It should also be clear that the studs 140 that are provided are approximately the desired height of the wall of the building being constructed. Moreover, wall section 130 further includes lower plate 132 , upper plate 134 and a plurality of studs (not shown) connected between lower plate 132 and upper plate 134 . As will be explained in more detail below, frame structure 110 is interposed between the two wall sections 120 , 130 to facilitate construction of the wall intersection.
[0016] FIG. 4 illustrates a cross-sectional view of frame structure 200 in accordance with an exemplary embodiment. It should be understood that frame structure 200 provides a cross-sectional view of frame structure 110 illustrated in FIG. 3 . As shown, frame structure 200 comprises a first support panel 210 having two opposing sides 212 and 214 and two outer edges 216 a and 216 b. In the exemplary embodiment, first support panel 210 is substantially rectangular in shape. Furthermore, frame structure 200 comprises two individual second support panels 220 , 230 that protrude from side 214 of first panel 210 at an approximately 90° angle. As such, the pair of individual second support panels 220 , 230 are positioned substantially parallel to one another. In the exemplary embodiment, the pair of second support panels 220 , 230 are also substantially rectangular in shape. Moreover, the pair of second support panels 220 and 230 each have respective outer sides 222 a and 232 a, respective inner sides 222 b and 232 b, as well as respective ends 224 and 234 . In the exemplary embodiment, frame structure 200 is therefore formed with a recess 218 between inner sides 222 b and 232 b of second support panels 220 and 230 . It should be clear that while the exemplary embodiment is illustrate with second support panels 220 and 230 being secured to first support panel 210 at a 90° angle, the application is in no way intended to be limited to such implementation. It is envisioned that alternative angles are possible pending on the particular design of the building being constructed.
[0017] In implementation, the pair of second support panels 220 and 230 are secured to first support panel 210 by any applicable means. For example, second support panels 220 , 230 can be secured to first support panel 210 by nails, adhesive, screws, a combination of these materials, or any other suitable means. In an alternative implementation, second support panels 220 , 230 are manufactured as a single piece of material with first support panel 210 . Frame structure 200 can be manufactured from recycled material, plywood, chipboard, or any other suitable material. In one embodiment, the individual support panels, 210 , 220 and 230 of frame structure 200 can be milled out of plywood and connected with a suitable adhesive.
[0018] As explained above and illustrated in FIG. 3 , frame structure 200 is interposed between wall section 120 and wall section 130 during construction. It is appreciated that frame structure 200 is inserted between lower plates 122 , 132 and upper plates 124 , 134 of walls sections 120 and 130 , respectively. Accordingly, in implementation, frame structure 200 will be substantially the same length as the plurality of studs 140 shown in FIG. 3 .
[0019] FIG. 5 illustrates a side partial view of frame structure 200 interposed between the two wall sections in accordance with an exemplary embodiment. As shown, frame structure 200 is coupled to the upper surface 124 of lower plate 122 of wall section 120 by connector bracket 310 . It should be appreciated that connector bracket 310 can be any conventional bracket capable of connecting frame structure 200 and lower plate 122 and is not limited to the design illustrated in FIG. 5 . Furthermore, frame structure 200 is secured to lower plate 122 such that the inner sides 214 a, 214 b of frame structure 200 are in substantially the same plane as side edge 126 of lower plate 122 . Furthermore, the pair of second support panels 220 , 230 of frame structure 200 are secured to first support panel 210 with a premeasured width such that outer sides 222 a and 232 a are in substantially the same plane as the side edges 134 a, 134 b of lower plate 132 of wall section 130 . Alternatively, second support panels, 220 and 230 can be positioned closer together (e.g., 1 inch apart). Finally, while not shown, it should be appreciate that the opposite end of frame structure 200 is secured to the upper plates 124 , 134 of wall sections 120 , 130 in a substantially similar manner.
[0020] Once secured between wall sections 120 and 130 , frame structure 200 is properly positioned to support the load imposed upon the intersection areas of the respective wall structure. In this regard, it is appreciated that first support panel 210 as well as the pair of second support panels 220 , 230 are designed so as to assume the principal load carrying function.
[0021] To facilitate construction and design of the particular building, it is appreciated that the inner sides 214 a, 214 b of first support panel 210 serve to receive the inner wall structure of the house for wall section 120 , such as sheetrock, paneling, etc. Similarly, in the exemplary embodiment, the outer sides or edges 212 of first support panel 210 can server to receive the outer side wall structure of the building such as exterior paneling, siding, etc. Moreover, the outer sides 222 a and 232 a of the pair of respective second support panels 220 and 230 serve to receive the inner wall structure of the house for wall section 130 , such as sheetrock, paneling, etc. It should be appreciated that sheetrock, paneling, siding, etc. are attached to the support panels by, screws, nails, adhesive, or any other suitable means.
[0022] FIG. 6 illustrates a cross-sectional view of frame structure 600 in which specific dimensions are provided in accordance with an exemplary embodiment. As shown, first support panel 610 has a length of approximately 6½ inches and a width of approximately ¾ inches. Moreover, the pair of second support panels 620 and 630 have a length of approximately 1½ inches. Further, second support panels 620 and 630 are secured to first support panel 610 such that their respective outer surfaces 622 a and 632 a are positioned approximately 1½ inches from the respective outer edges 616 a and 616 b of first support panel 610 . As a result, there is sufficient space provided by frame structure 600 enabling sheetrock, paneling, and the like to be secured to inner sides 614 a and 614 b of first support panel 610 as well as to the respective outer surfaces 622 a and 632 a of second support panels 620 and 630 . It should be appreciated, however, that the second support panels 620 and 630 can be shorter than 1½ inches (e.g., 1 inch) or longer as needed, so long as sufficient space is provided for finishing materials, such as sheetrock, to be attached. It is reiterated that while these dimensions are provided for the embodiment illustrated in FIG. 6 , the invention is by no means intended to be limited by these dimensions.
[0023] FIG. 7 illustrates a side partial view of frame structure 700 interposed between two wall sections 120 , 130 in accordance with another exemplary embodiment. In contrast to the embodiments described above, frame structure 700 comprises a pair of first support panels 710 a, 710 b. Moreover a pair of second support panels 720 and 730 are secured, respectively, to the pair of first support panels 710 a, 710 b. Additionally, a third support panel 740 can be secured between the pair of second support panels 720 and 730 . As such, a recess 750 is provided between second support panels 720 and 730 . In one embodiment, second support panels 720 and 730 as well as third support panel 740 are prefabricated as a single piece of material. In any event, it should be appreciated that frame structure 700 comprises similar functional aspects as frame structure 200 . For example, in a similar manner as shown in FIG. 5 , the pair of first support panels 710 a and 710 b are coupled to the upper surface 124 of lower plate 122 of wall section 120 by a pair connector bracket 310 a, 310 b. Furthermore, frame structure 700 is secured to lower plate 122 such that the respective inner sides 714 a and 714 b of the pair of first support panels 710 a and 710 b are in substantially the same plane as side edge 126 of lower plate 122 . Furthermore, the pair of second support panels 720 , 730 are secured to the pair of first support panels 710 a and 710 b with a premeasured width such that outer sides 722 a and 732 a are in substantially the same plane as the side edges 134 a, 134 b of lower plate 132 of wall section 130 .
[0024] It is appreciated that the frame structures of the present invention can be particularly designed and dimensioned for walls of various thickness. For example, the frame structures of the present invention can include pre-drilled holes to facilitate easy installation during building construction. In addition, it is further contemplated that the exemplary frame structures of the present invention can easily and conveniently be prefabricated or premanufactured from various suitable materials as discussed above. It is therefore appreciated that the frame structure inserts or assemblies have the capability of reducing both material and the labor cost over conventional construction techniques for the T-intersection framing structure used within framed walls of residential structures and the like as well as any other structure/wall that can utilize the T-intersection framing design. In addition, the design of the present invention enables the T-intersection to be easily insulated and in fact improves the resistance of the wall structure by reducing heat losses and gains to the interior of the structure. Also, as explained above, the frame structures of the present invention provide an attachment surface for the full height of inside and outside wall coverings about the framed intersection.
[0025] Finally, FIG. 8 illustrates an advantageous shipping configuration of the frame structures in accordance with an exemplary embodiment. As shown, a plurality of frame structures 810 a - 810 d can be stacked in an efficient manner are shown in FIG. 8 . It should be clear that the plurality of frame structures 810 a - 810 d employ the same design as the exemplary structure described above with respect to FIG. 3-5 . Accordingly, in addition to the foregoing advantages described above, the exemplary frame structure enables this further benefit to aid the construction of a building.
[0026] While the foregoing has been described in conjunction with an exemplary embodiment, it is understood that the term “exemplary” is merely meant as an example, rather than the best or optimal. Accordingly, the application is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention.
[0027] Additionally, in the preceding detailed description, numerous specific details have been set forth in order to provide a thorough understanding of the present invention. However, it should be apparent to one of ordinary skill in the art that the inventive test circuit may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the application.
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A support frame for supporting an intersection between a first wall section and a second wall section. The support frame including a first support panel having a top edge and a bottom edge, which are configured to be positioned between respective upper and lower plates of the first wall section. Moreover, the support frame has a pair of second support panels affixed to the first panel, and each second support panel has a top edge and a bottom edge configured to be positioned between respective upper and lower plates of the second wall section.
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This application is a national stage filing under 35 U.S.C. 371 of International Application PCT/IT2005/000343, filed on Jun. 16, 2005. PCT/IT2005/000343 was published under PCT Article 21(2) in English.
TECHNICAL FIELD
This invention concerns a device for dispensing CO 2 , that is to say carbon or carbon dioxide, which can be fitted in aquariums or containers holding live fish.
More specifically, the invention refers to a device for dispensing carbon dioxide that can be combined with a pumping device for aquariums, able to guarantee and optimise the process of diffusing and dissolving CO 2 particularly useful for the biological equilibrium of the aquarium and for its fertilisation.
This invention provides a solution for the correct distribution of carbon inside aquariums, guaranteeing the diffusion of the microbubbles and dissolving them in the water in a much more effective way.
The invention can be applied in particular in the industry of products for small pets, with particular reference to the aquarium sector.
BACKGROUND ART
It is known that carbon is one of the most important elements for plants, since it allows them to build support tissues (cellulose is, essentially, a carbon skeleton) and energy reserves (starch, which is a glucose polymer, a sugar) and to have, thanks to photosynthesis, the chemical energy that makes it possible to produce enzymes, proteins and everything else necessary for plant metabolism.
The use of CO 2 in aquariums is also chemical: it helps to stabilise the pH at values below 7, difficult to achieve with other methods, which are at the same time compatible with plant growing (such as, for example, filtration over peat) and long-lasting (like additives for lowering pH values).
However, the diffusion of carbon in the water of aquariums is always very limited and in order to have healthy and luxuriant plants it is therefore necessary to administer the carbon they need in an artificial form.
Carbon can be distributed in aquariums by means of various techniques, always in the gaseous state.
The most common method is to dispense amounts of carbon or carbon dioxide directly in the aquarium by using CO 2 cylinders equipped with pressure .gauges, pressure reducers and special water diffusers.
According to some systems the CO 2 bubbles follow a zigzag path, from the bottom upwards. This path ends in a dome-shaped cap which holds the bubbles until they dissolve in the water, preventing them from being lost in the atmosphere.
The disadvantages of this system consist of the fact that a period of activation is necessary, cleaning is difficult and there is a continuous accumulation of CO 2 in the cap, so that at a certain point it is lost. In addition, the area close to the dispenser, and to the cap in particular, is rich in CO 2 while the area furthest away is poor in CO 2 .
In these dispensing models the CO 2 cap consists of a plastic rectangle inside which the CO 2 is accumulated and from which it inevitably escapes and is scattered on the surface.
This occurs when the mixing time of the gas with the water is greater than the time needed to fill the cap (area close to the cap saturated with carbon dioxide).
According to other distribution systems, the CO 2 bubble is forced to enter an atomiser, i.e. a system consisting of a plastic cap to be positioned close to the bottom of the aquarium, where it has to pass through a membrane that divides the bubble into lots of microbubbles which rise directly to the surface and scatter.
This atomiser model does not stand up to high pressures and the device cannot therefore be adjusted to dispense a high number of bubbles per minute.
The Co 2 dispenser is sometimes combined with a water delivery pump, but systems ensuring total mixing are not foreseen: the bubbles of gas are not directly struck by the flow of water and/or the microbubbles are not held in the mixing chamber, becoming scattered on the surface, and/or the adjustment of the pump output is dealt with by the user who is unlikely to have the ability to optimise the mixing.
For example, in the patent DE20015086U1, a pump dispenser model, the gas output goes directly to a pump which is designed to reduce the bubble into lots of microbubbles.
In this case the majority of the bubbles struck by the pump flow scatter on the surface, without being completely mixed with the water.
In the known dispensers in which the CO 2 bubble is forced to follow a zigzag path, above all those just installed and because of friction along the path, an “activation period” is required because the CO 2 bubble is unable to complete path and stops after a short distance.
This means that several bubbles accumulate in the same point until the bubble is so big that it slips out of the dispenser and is lost on the surface. After a certain period of time (this is the “activation” period) a coating is created along the entire path which allows the bubble to slide along individually and easily.
There are other distribution systems, but in general their use has revealed considerable disadvantages, which the invention intends to remedy, mainly concerning the fact that the traditional distribution of CO 2 is not very effective since some of the dispensed gas bubbles are not completely mixed with the water but rise almost immediately and are lost outside the system, thus thwarting their effect.
DESCRIPTION OF THE INVENTION
This invention proposes to provide a device for dispensing CO 2 in aquariums which is able to eliminate or at least reduce the problems described above.
The invention also proposes to provide a device for dispensing CO 2 in aquariums which is easy to produce in order to be economically advantageous.
This is achieved by means of a CO 2 dispenser whose features are described in the main claim.
The dependent claims of the CO 2 dispenser for aquariums describe advantageous embodiments of the invention.
The main advantages of this solution, in addition to those deriving from its construction simplicity, concern above all a better dissolving of the carbon in the water, due to the extremely reduced volume of the gas bubbles dispensed.
The dispenser according to the invention is the part of the CO 2 system immersed in the water which is designed to guarantee the mixing of the aquarium water and the CO 2 .
The dispenser according to the invention substantially comprises a pump with a sponge prefilter, a transparent plastic dispenser body with a 20 ppi sponge and a mesh cover.
Thanks to the flow of water from the pump aimed at the gas output, the CO 2 bubble is split into a number of microbubbles; and:
1) a turbulent motion is created inside the dispenser chamber, 2) the microbubbles are held inside the dispenser by the sponge,
the entire initial CO 2 bubble is completely dissolved in the water.
Moreover, thanks to the flow created by the pump, there is a continuous cycle of CO 2 -poor water entering the dispenser and CO 2 -rich water coming out of it, thus guaranteeing a uniform concentration of carbon dioxide in the aquarium and preventing the presence of CO 2 saturated and unsaturated areas.
The system according to the invention presents numerous important advantages, such as:
the carbon dioxide is dissolved 100% (maximum effectiveness); there is no saturation of CO 2 in just one part of the aquarium, with a perfectly uniform concentration of carbon dioxide in the tank; installation is easy and fast; the dispenser is universal, it can be used with any CO 2 dispensing system such as cylinders, fermentation, etc.; the system does not require an “activation” period.
DESCRIPTION OF THE DRAWINGS
Other features and advantages of the invention will become evident on reading the description below of one embodiment of the invention, given as a non-binding example, with the help of the accompanying drawings in which:
FIG. 1 shows a schematic side view of the overall dispenser according to the invention.
FIG. 2 shows a schematic view during its use in the aquarium.
DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION
The CO 2 dispenser according to the invention, indicated in general with the reference number 10 , substantially consists of a dispenser casing 11 or body, connected to a water pump 12 which is in turn fitted with a sponge prefilter.
According toga preferred embodiment, the dispenser body 11 is made from transparent plastic and is equipped with an inner filtering element 13 , which can consist of a sponge with a consistency of around 20 ppi, this sponge occupying approximately all the lower half ,of the dispenser body, in an area opposite to where the pump 12 is fitted.
It is also possible to use any kind of filtering element which is able to retain the microbubbles and allow only the water in which the CO 2 is dissolved to pass through.
The end of the dispenser 11 , that is to say the exterior of the part containing the filtering element 13 , can be fitted with a mesh cover 14 .
The dispenser 11 is also equipped with a mixing chamber 15 between the sponge 13 and the area where the pump 12 is fitted.
The flow delivered by the pump 12 enters an inlet duct 16 positioned horizontally.
The upper part of the dispenser body 11 is fitted with the CO 2 injector 17 , which emits quantities of carbon in the gaseous state, that is to say carbon dioxide from a duct 18 connected to a supply cylinder or other source.
It can be noted that the flow of water delivered through the inlet duct 16 , positioned horizontally inside the chamber 15 , is substantially at right angles to the CO 2 injector 17 which is instead positioned vertically, with the gas output area close to the water output area.
The flow of water from the pump 12 is therefore mixed with the flow of gas delivered by the injector 17 , since the water and gas meet at right angles to each other at the start of the mixing chamber 15 .
Thanks to the flow of water from the pump 12 striking the output of the gas 17 , the bubbles of CO 2 are broken up into lots of microbubbles.
A turbulent movement is in fact created inside the dispenser chamber 15 , causing the formation of microbubbles which are retained inside the dispenser by the sponge 13 .
In this way, the entire CO 2 bubble is completely dissolved in the water, becoming an integral part of it.
Moreover, thanks to the flow created by the pump 12 , a continuous cycle of CO 2 -poor water is established. This enters the dispenser 11 (arrow A FIG. 1 ) and CO 2 -rich water exits through the mesh cover 14 (arrow B FIG. 1 ), thus ensuring a uniform concentration of carbon dioxide in the tank, avoiding the presence of CO 2 saturated and unsaturated, areas in the aquarium.
The CO 2 distribution system described above presents numerous important advantages compared to traditional dispensers.
Above all, the dispenser is particularly efficient as the carbon dioxide is dissolved 100%.
There is also a totally uniform concentration of carbon dioxide in the tank due to the absence of CO 2 saturation in individual parts of the aquarium.
Other advantages concern the possibility of easy and fast installation of the dispenser and its universality and versatility, due to the fact that it can be used with any CO 2 distribution system such as cylinders, fermentation, etc.
Finally, the system does not require the “activation time” of traditional dispensers, since in the dispenser according to the invention the microbubbles are distributed and mixed in the water right from the start. The particles of carbon are thus dispensed directly in the microbubbles, with all the consequent advantages for plant and animal vitality in the aquarium.
The invention is described above with reference to a preferred embodiment. It is nevertheless clear that the invention is susceptible to numerous variations that lie within its scope, in the framework of technical equivalents.
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A device for dispensing CO 2 , that is to say carbon or carbon dioxide, which can be fitted in aquariums or containers for holding live fish, comprising a dispenser casing ( 11 ) or body, equipped with a mixing chamber ( 15 ) into which a flow of water is delivered by a pump ( 12 ) and a flow of CO 2 from an infeed duct ( 18 ).
The mixing chamber ( 15 ) being bordered by at least one filtering element ( 13 ) which occupies the lower half of the dispenser body ( 11 ), closed at the front by a mesh cover ( 14 ).
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This invention relates to venting systems for gas-burning appliances. More specifically, the present invention relates to a device that adjusts the dilution air flow and combustion product flow from an appliance to adapt the appliance vent gas composition for venting systems built from a variety of materials.
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
Conventional gas heating appliances such as furnaces, boilers, and water heaters provide the consumer with safe, economical space and water heating, while requiring little maintenance during a long lifespan. These appliances typically use single wall galvanized vent connectors and either a masonry chimney or Type B vent pipe to vent the flue gases created during operation. The American National Standards Institute (ANSI) categorizes gas appliances based on the pressure produced in a special test vent and the difference between the actual temperature and dew point temperature of the flue gas.
A category I appliance is one which has a vent expected to operate under negative static vent pressure with a minimum of condensation. A category I furnace or boiler has an Annual Fuel Utilization Efficiency (AFUE) range of 78% minimum to approximately 83%. Moisture does not condense from the flue gas in category I appliances because the actual flue gas temperature is generally more than 140° F. above its dew point temperature. Traditional draft hood equipped appliances are category I appliances. However, many mid-efficiency, fan-assisted appliances are category I appliances as well. Such appliances can be made category I appliances by adjusting the flue gas temperature to be in the same range as the traditional category I appliance, and by designing the vent system to maintain a negative pressure even in the presence of the fan. Venting systems for category I appliances typically include Type B vents, lined masonry chimneys, and single wall metal vents.
Category II appliances also operate with negative vent pressure. However, the vent gas temperature is generally less than 140° F. above its dew point temperature. The condensation occurring in these appliances requires the designer to use a corrosion resistant vent to exhaust the flue gases. There are few, if any, category II appliances on the market.
Category III appliances operate with a positive vent pressure and with a vent gas temperature generally at least 140° F. above its dew point temperature. Their AFUE ranges from approximately 78% to 83%. Because the pressure in the vent exceeds that of the surrounding atmosphere, these appliances require an airtight vent to prevent leakage of flue gases before they reach the outside venting location. An example of a category III appliance would be a mid-efficiency furnace that is vented horizontally through the wall. Venting systems for category III appliances typically include high temperature plastic and single wall stainless steel metal vents.
Category IV appliances include furnaces, boilers, and other devices that operate with a positive vent pressure and with a vent gas temperature less than 140° F. above its dew point temperature. They generally have AFUE values above 83%. Because the pressure in the vent exceeds that of the surrounding atmosphere and because condensation occurs in the vent, these appliances require an airtight, corrosion-resistant vent that is equipped for condensate disposal. Category IV appliances are usually high-efficiency, condensing devices. Venting systems for category IV appliances typically include high temperature plastic, polyvinyl chloride ("PVC"), or chlorinated polyvinyl chloride ("CPVC") vents.
ANSI Z21.47-1993 provides the current category certification requirements for gas furnaces. These requirements define and use the concept of Steady State Thermal Efficiency (SSTE) in making a category determination. SSTE measures the appliance's operating efficiency by dividing the total gas energy input to the appliance into the amount of energy gainfully used by the appliance (essentially one minus the amount of energy expelled up the flue (wasted energy)) while the appliance is operating in a steady state. AFUE, on the other hand, is an overall assessment of an appliance's annual operating efficiency. ANSI Z21.47-1993 uses flue gas temperature and the flue gas carbon dioxide content to distinguish between category I and non-category I appliances based on a SSTE of 83%. The flue gas temperature of an appliance with a given SSTE varies with the amount of excess air used for combustion and the amount of dilution air added prior to the vent. These amounts, in turn, determine the percentage of carbon dioxide in the flue (7-9% for most appliances). The ANSI specification indicates, for example, that an appliance having between 7-9% carbon dioxide in the flue gas qualifies as a category I appliance when the flue gas is approximately 140° F. or more above its dew point temperature.
Assigning an appliance to a specific category is important because the category determines the type, size, material, and installation requirements of the venting system for that specific appliance. For example, a category I appliance may use traditional venting materials such as Type B vent pipe or a masonry chimney, while a category IV furnace requires a vent system built from corrosion resistant materials, and category III and IV appliances require airtight vent systems.
The flue gas of natural draft appliances, such as furnaces and water heaters, contains a large amount of water vapor. As the industry has moved to high efficiency appliances, and subsequently to lower flue gas temperatures, condensation of water and corrosive substances from the flue gas onto exhaust conduit surfaces has become a major design issue. Most new appliances are connected to an old vent, often using a single wall vent connector. In many cases, the vent is a masonry chimney. However, in today's building codes, the use of single wall metal vent connector is severely limited, and most masonry chimneys require relining before the new appliance may be installed. Converting to a Type B connector from a single wall connector may cost the building owner up to $60.00, while relining a chimney to protect against condensation can cost from around $200 to $800. For another example, problems with category III appliances using high temperature plastic vents have prompted some jurisdictions and some appliance manufacturers to prohibit the use of high temperature plastics. Alternative stainless steel vent systems cost roughly twice as much as high temperature plastic systems, in the $100 to $300 range. In short, the existing vent may be completely inadequate for the new appliance and may either prevent the building owner from installing gas appliances or require the building owner to undergo an expensive and time consuming vent system replacement.
In an attempt to avoid these costs, several manufacturers have designed appliances with draft hoods that entrain dilution air into the vent. Entraining dilution air into the vent reduces the amount of condensation formed during operation and therefore reduces the number of installations which would require chimney relining. Unfortunately, this process also allows heated room air to escape in an uncontrolled fashion, both while the appliance is operating and while the appliance is idle. The escaping heat increases the heat load on the building and therefore increases the energy cost associated with controlling the building temperature. In addition, the typical draft hood equipped appliance is susceptible to backdrafting, which is especially troublesome in the multi-story housing market.
BRIEF SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to decrease the installed cost of a modern gas appliance.
Another object of the present invention is to decrease the overall energy consumption of a building.
Still another object of the present invention is to increase the installation venting options available to the gas appliance installer.
Yet another object of the present invention is to reduce backdrafting and increase the safety of the appliance vent system.
One or more of the preceding objects, or one or more other objects which will become plain upon consideration of the present specification, are satisfied in whole or in part by the invention described in this specification.
One aspect of the invention is a gas-burning appliance adapted for varying the proportions of combustion products to dilution air in its vent gas. The appliance can be a furnace, a water heater, a boiler, or some other gas appliance which is externally vented and normally used within a building or other structure.
A combustion chamber is provided for burning gas and producing combustion products. A flue gas outlet is included for passing flue gas to a mixing chamber. A dilution air inlet is used for passing dilution air into the mixing chamber. The appliance has at least one valve element defining at least a first dilution air aperture and at least a first combustion product aperture.
In one embodiment of the invention, the valve element is a flat plate and the apertures are pairs of holes in the plate. The different apertures can also be formed in other ways, as by the cooperation of two relatively movable elements (analogous to the rotating covers of some spice or parmesan cheese dispensers).
The valve element may be fixed, or the valve element may be movable between one or more positions. In the first position of a moveable valve element, the first dilution air aperture is placed between the dilution air inlet and the flue gas mixing chamber, and the first combustion product aperture is placed between the combustion chamber and the flue gas mixing chamber. The first dilution air and first combustion product aperture pair are respectively adapted to provide a first ratio of dilution air to combustion products passing into the flue gas mixing chamber when the valve element is in its first position.
In the second position of a movable valve element, the second dilution air aperture is positioned between the dilution air inlet and the flue gas mixing chamber, and the first combustion product aperture is positioned between the combustion chamber and the flue gas mixing chamber. The second dilution air and second combustion product aperture pair are respectively adapted to provide a second ratio of dilution air to combustion products passing into the flue gas mixing chamber when the movable valve element is in its second position.
The first and second ratios of dilution air to combustion products passing into the flue gas mixing chamber are different, due to the different size hole ratios or other adaptations of the dilution air aperture and combustion product aperture. This allows the combustion-products-to-dilution-air ratio to be selected to match the appliance to the venting system it will be attached to. This allows modern, high-efficiency gas appliances to be connected to traditional venting systems without causing vent corrosion, and without producing an inappropriately high or low pressure of combustion products in the vent.
In the configuration in which the valve element is fixed, the first dilution air aperture is placed between the dilution air inlet and the flue gas mixing chamber. The first combustion product aperture is placed between the combustion chamber and the flue gas mixing chamber. The valve element is secured in this position to continuously provide a first ratio of dilution air to combustion products in the flue gas mixing chamber.
Another aspect of the invention is an adapter for varying the proportions of combustion products to dilution air in the vent gas of a fuel-burning appliance. The adapter has a dilution air inlet; a combustion product inlet; a flue gas mixing chamber, and at least one fixed or movable valve element. The valve element defines at least a first dilution air aperture and at least a first combustion product aperture, and has at least a first position and hole ratio as described before. The adapter can be part of the appliance, part of the venting arrangement, or a separate, add-on installation for attachment between an appliance and a venting arrangement.
Yet another embodiment of the invention is a flue assembly adapted for varying the proportions of combustion products to dilution air passing through it. The assembly comprises a dilution air inlet; a combustion product inlet; a flue gas mixing chamber, and at least one fixed or movable valve element as previously defined. Again, the assembly provides one or more ratios of dilution air to combustion products passing into the vent. This flue assembly can be installed in a building to adapt the building to receive a variety of gas appliances having different categories.
One significant advantage of the invention is its simplicity, as the flows of dilution air and combustion air can be coordinated by operating a single valve element. The valve element or adjacent structure can be marked to indicate the proper positions of the valve element for different categories of appliances (if it is installed as part of the vent system) or different vent types (if it is incorporated in the appliance), or both. This multiple-function valve element makes selection of the proper valve element position much less subject to miscalculations and errors, such as confusion about which of two separate valve elements controls the dilution air and which controls the combustion products. A fixed valve element would not require any adjustment in the field to obtain the correct ratio of dilution air to combustion products.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view illustrating one embodiment of the present invention.
FIG. 2 shows a cross-section of a movable valve aperture plate taken along line 2--2 in FIG. 1, and having three pairs of apertures for category I, III, and IV appliances.
DETAILED DESCRIPTION OF THE INVENTION
While the invention will be described in connection with one or more preferred embodiments, it will be understood that the invention is not limited to those embodiments. On the contrary, the invention includes all alternatives, modifications, and equivalents as may be included within the spirit and scope of the appended claims.
FIG. 1 shows a gas burning appliance, for example a gas furnace, generally indicated by reference numeral 10. The appliance 10 burns natural gas, propane, or some other combustible gas in the combustion chamber 12. The resulting combustion product gases flow through the heat exchanger 14, the flue product passage 16, and the combustion flue inlet 18 into the flue gas mixing chamber 20. The combustion flue inlet 18 is shown in FIG. 1 as one end of the flue product passage 16. The appliance 10 also draws dilution air into the dilution air inlet opening 22 from outside the furnace 10, preferably from outside the building being heated. The dilution air then passes through a dilution air inlet 24, and into the mixing chamber 20. The combustion gases and dilution air both flow through the orifice plate 26, which is the valve element in this embodiment, then they mix in the flue gas mixing chamber 20 to form vent gases (combustion products mixed with dilution air). The blower 28 helps draw flue gas and dilution air through the mixing chamber 20 during on-cyles and helps exhaust the vent gases through the vent 29 to the outside atmosphere. The position of blower 28 downstream of the dilution air and combustion product inlet serves to restrict off-cycle air flows through the dilution air inlet and through the combustion flue inlet. The vent 29 may be constructed from any of the materials appropriate for a category I, II, III, or IV appliance. The blower 28 may be an integral part of the appliance, but is not so limited and may also be part of the vent system.
The orifice plate 26 includes first and second major faces 30 and 31 perforated by pairs of dilution air apertures and combustion product apertures that may be rotated and secured the dilution air opening 24 and the combustion flue inlet 18.
FIG. 2 shows an orifice plate 26 with three pairs of apertures: Category I apertures 32 and 34, and category III apertures 40 and 42, category IV apertures 36 and 38. Each "aperture" as defined here may include more than one opening within the scope of the present invention. The selected aperture 32, 36, or 42 passes combusting gas from the combustion flue inlet 18. The selected aperture 34, 38 or 40 passes dilution air from the dilution air inlet 24. The orifice plate 26 may contain as many or as few aperture pairs as the size of the manufacturer's orifice plate, the combustion flue opening, and the dilution air opening allow. The selected aperture pair 32-34, 36-38, or 40-42 controls the ratio of dilution air and combustion product gases in the flue gas mixing chamber 20 so the resulting vent gas may pass through the selected or existing vent 29 without damaging the vent 29 materials or causing undesired condensation. In FIG. 2, the aperture pair 32-34 have been selected by registering them with the dilution air inlet 24 and the combustion flue inlet 18.
Each diametrically opposed aperture pair 32-34, 36-38, 40-42 may restrict the dilution air and flue gas flows by different amounts and in different ratios to configure the appliance for a different type of vent 29 material. During installation of the appliance 10, the installer rotates the orifice plate 26 to its proper position based on the construction of the vent 29. The proper position is indicated by the category legends I, III, and IV, one of which is aligned with an external reference mark 44. The proper position places the particular pair of holes 32-34, 36-38, 40-42 which match the vent gas mixture for the construction of vent 29 over the dilution air inlet 24 and the combustion flue inlet 18.
The openings in the orifice plate 26 (and the blower 28, if present) generate flow resistance that makes the appliance 10 less susceptible to backdrafting than a typical draft hood equipped appliance. The flow resistance also restricts the flow of dilution air during the appliance 10 off-cycle, which helps to prevent heated air from escaping freely through the vent 29. Thus, less energy is required to maintain room temperature.
Each appliance 10 manufacturer may use different diameters or shapes for the dilution air inlet 24 and the combustion flue inlet 18. The orifice plate 26 itself and its hole pairs 32-34, 36-38 and 40-42 are not restricted to a round shape, but need only control the ratio of dilution air to flue gas entering the post-orifice mixing chamber region 20. The manufacturer uses Table 1 to determine the proper size for the orifice plate 26 hole pairs, 32-34, 36-38, and 40-42, that will appropriately adjust the dilution air/flue gas mixture for their desired appliance category. The orifice plate 26 is preferably constructed from a non-corrosive stainless steel.
Natural gas produces about 1,000 Btus of heat energy per cubic foot of gas burned. About 14 cubic feet of air are needed per cubic foot of natural gas for acceptable combustion and a gas appliance with no dilution air needs to exhaust about 15 cubic feet of combustion products per 1,000 Btu. A gas furnace that operates at 100,000 Btus per hour needs to exhaust about 1,500 cubic feet of combustion products per hour or about 22 standard cubic feet per minute (scfm). Dilution air, as used in Table 1, is measured as a percentage of flue products. A table value of 100 percent dilution air, for example, means approximately 15 cubic feet of dilution air per 1000 Btu of gas burned, for a total of 30 cubic feet of vent gases per 1,000 Btu. In other words, a hole pair in the orifice plate 26 must be sized to allow equal amounts of dilution air and combustion gas to mix in the flue gas mixing chamber 20. A gas furnace that operates at 100,000 Btu per hour, which needs 100 percent dilution air, needs to exhaust approximately 44 scfm of vent gases. As shown in Table 1, the percentage of dilution air required differs depending on whether the appliance uses outdoor (42° F.) dilution air, or indoor (60° F.) dilution air.
As an example, assume that a manufacturer anticipates that its indoor dilution air, SSTE 81 appliance will be installed in locations that may have one of three venting systems: PVC, CPVC, or high-temperature plastic. In this situation, rather than design and manufacturing three separate appliances that meet the vent gas requirements for each possible venting system, the manufacturer may design and manufacture one appliance with an orifice plate 26 having three aperture pairs 32 and 34, 36 and 38, and 40 and 42. Table 1 indicates, for example, that the orifice plate 26 should include a hole pair 36 and 38 that mixes approximately 300% dilution air to combustion products for a PVC system, a hole pair 32 and 34 that mixes approximately 110% dilution air to combustion products for a CPVC system, and a hole pair 40 and 42 that mixes approximately 150% dilution air to combustion products for a high-temperature plastic vent system. The suggested mixing percentages in Table 1 are targeted at meeting the flue gas criteria (also shown in Table 1). For example, keeping the flue gas temperature under 140° F. in a PVC vent system. Furthermore, the installer need not know beforehand which venting system the installation site uses, because the installer can rotate the orifice plate 26 during installation to adjust the flue gas output of the appliance 10 for the venting system used in the building.
The orifice plate 26 is not limited to any particular number of apertures or sets of apertures, nor to any particular aperture shape or number of apertures. The manufacturer, for example, may choose to use a large plate with enough area for many aperture pairs, or a small plate with enough area for fewer aperture pairs. The apertures need only be sized and positioned correctly to adjust the mixture of combustion product gases and dilution air according to Table 1. The SSTE ranges and the flue gas criteria shown in Table 1 are not all inclusive. The invention may be used with additional SSTE ratings or additional criteria not indicated in the table simply by determining the criteria of interest and adjusting the orifice plate 26 aperture pairs such as 32-34, 36-38 or 40-42 to meet those criteria.
TABLE 1______________________________________Approximate Vent Dilution Air Requirements for Gas Appliances______________________________________Venting System: Plastic PVC Plastic High Temperature Vent System CPVC Vent Plastic Vent System SystemFlue gas Flue Gas Flue Gas Vent DriesCriteria: Temperature Temperature Completely Less Than Less Than 140° F. 210° F.Outdoor (42° F.)Dilution AirSSTE 80 350% 130% 200%SSTE 81 300% 110% --SSTE 82 250% 80% --SSTE 83 200% 60% --Indoor (60° F.)Dilution AirSSTE 80 350% 130% 100%SSTE 81 300% 110% 150%SSTE 82 250% 80% 300%SSTE 83 200% 60% --SSTE 85 100% 10% --SSTE 87 30% 0% --______________________________________Approximate Vent Dilution Air Requirements for Gas Appliance______________________________________Venting High Temperature Type B Interior ExteriorSystem: Plastic Vent Masonry Masonry Vent System System Chimney ChimneyFlue gas All Interior Maintain Maintain MaintainCriteria: Portions of Negative Negative Negative the Vent Pressure; Pressure; Pressure; Dry by the Avoid Avoid Avoid End of the Excessive Excessive Excessive Burner On- Conden- Conden- Conden- cycle sation sation sationOutdoor (42° F.)Dilution AirSSTE 80 100% 0% -- --SSTE 81 200% 0% -- --SSTE 82 -- 0% -- --SSTE 83 -- 0% -- --Indoor (60° F.)Dilution AirSSTE 80 50% 0% 50% --SSTE 81 100% 0% -- --SSTE 82 150% 0% -- --SSTE 83 200% 0% -- --SSTE 85 -- -- -- --SSTE 87 -- -- -- --______________________________________ *Dilution air required to cool flue gases to a safe temperature is determined by the requirements for the warmest expected day (60° F.); condensation is based on a typical day (42° F.).
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A gas appliance, flue assembly, or vent adapter including an adjustable flow regulator which regulates the proportions and volume of dilution air and combustion products into the vent is disclosed. The flow regulator can be adjusted to allow a given appliance to exhaust vent gases through a range of different venting systems constructed from a wide range of materials. The appliance installer may adjust the appliance vent gases for a particular pre-existing or installed vent. The flow regulator also provides flow resistance which helps prevent backdrafting and the free escape of dilution air (which may be heated room air in some instances) through the vent to the outside atmosphere.
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FIELD OF THE INVENTION
[0001] The present invention generally relates to medical devices and methods. More particularly, the present invention relates to apparatus and methods for the ultrasonically enhanced delivery of therapeutic or contrast agents within the vascular and lung areas or other corporeal lumens.
BACKGROUND OF THE INVENTION
[0002] Despite the significant progress of medical technology, vascular and lung diseases, as well as arterial thrombosis (blood clots in arteries), remain frequent, costly and serious problems in health care. Current methods of treatment such as drugs, interventional devices, and/or bypass surgery are usually expensive and not always effective, even sometimes causing additional problems. For example, drugs can also dissolve beneficial clots or interventional devices can injure healthy tissue to cause potentially fatal bleeding complications or to form scarring or cellular growth which may itself eventually become a serious obstruction in, for example, a blood vessel (a process known as restenosis).
[0003] Ultrasonic energy has been used for enhancing the intravascular delivery of drug, to dissolve clot acoustically, disrupt mechanically and inhibit restenosis. Such energy can be delivered intravascularly using specialized catheters having ultrasonically vibrating surface at or near their distal ends. One type of ultrasonic catheter delivery system uses a wire or other axial transmission element to deliver energy from an ultrasonic energy source, located outside the patient to the internal organs, to desired corporeal lumens. (See, for example, U.S. Pat. Nos. 5,002,059, 5,324,255, 5,345,940, and 5,699,805, each of which is incorporated herein by reference.) Such catheters are rigid and cannot be easily inserted through narrow and tortuous vessels and may cause serious damage to vascular walls.
[0004] A second type of catheter has ultrasonic transducers mounted directly on their distal ends. See, for example; U.S. Pat. Nos. 5,362,309, 5,318,014, 5,315,998, 5,269,291, 5,197,946, 6,001,069, and 6,024,718, each of which is incorporated herein by reference. Despite enhanced safety and the fact that there is no need to employ a transmission element along the entire length, these catheters suffer from limited ultrasound energy, and the transducer-catheter design is still problematic.
[0005] Another type of catheter has an ultrasonic transducer or ultrasound transmission element with a central orifice in the distal end to impart ultrasonic energy into liquid and simultaneously deliver it to a corporeal lumen. See, for example, U.S. Pat. Nos. 5,735,811 and 5,197,946, each of which is incorporated herein by reference. Although these catheters are more effective and liquid delivery is more convenient, there are design difficulties and limitation of ultrasound energy from longitudinal waves.
OBJECT OF THE INVENTION
[0006] It is an object of the invention to provide an improved method and device for catheter drug delivery.
[0007] It is also an object of this invention to provide a method and device for catheter drug delivery using ultrasound energy.
[0008] It is another object of the invention to mix different drugs ultrasonically and deliver them to a desired corporeal lumen ultrasonically.
[0009] It is a yet another object of the invention to mix drug-liquid solutions with a gas (for example, saline with oxygen) ultrasonically and deliver the mixture to a desired corporeal lumen ultrasonically.
[0010] It is a further object of the invention to provide a method and device for delivering drugs to an intravascular area or/and a corporeal lumen, to dissolve blood clots.
[0011] It is a yet further object of the invention to treat a blocked and narrowed blood vessel with ultrasound waves.
[0012] These and other objects of the invention will become more apparent from the discussion below.
SUMMARY OF THE INVENTION
[0013] The present invention relates to apparatus and method for the ultrasonically enhanced delivery of therapeutic or contrast agents within the vascular and lung area or other desired corporeal lumens. Ultrasonic waves are applied to a vascular area, lung or any corporeal lumen without requiring direct contact between ultrasound transducer tip and the patient's body, particularly to dissolve blood clots.
[0014] According to the present invention, a catheter system comprises an ultrasound transducer having a distal tip with a radial surface and a distal end surface. The ultrasound transducer is disposed in a chamber at the proximal end of the catheter, and the transducer radiation surface or tip directs ultrasound waves or energy forward into the catheter coaxially via liquid. Longitudinal ultrasound waves induce wave motion in fluid adjacent to the transducer distal end. While particularly intended to enhance the absorption of therapeutic agents delivered to certain body lumens, the catheter system of the present invention is also useful for the delivery of ultrasonic energy to a desired location. The transducer radiation surface or transducer tip, may be cylindrical, flat, concave, convex, irregular or have a different shape-geometry to radiate ultrasound energy into catheter.
[0015] The catheter of the present invention may comprise a proximal tubing for delivering therapeutic agent from a reservoir by pump or syringe. The tubing may be located in front of or behind the radiation surface.
[0016] In a first embodiment of the invention, an ultrasound transducer and tip are mounted in a proximal portion of a catheter body, located outside of the body of a patient. The remainder of the catheter distal to the proximal portion may be inserted into a blood vessel or attached to a body lumen, to drive a therapeutic agent ultrasonically and/or deliver ultrasonic energy.
[0017] In a second embodiment, the distal tip of the transducer does not have an orifice, which is very important to create and deliver ultrasound energy fully to a vessel or body lumen.
[0018] In a third embodiment, the catheter system comprises a catheter body, mechanically coupled with an ultrasound transducer through a housing or tip node, which is where the transducer body is outside the catheter. In this way, the catheter body can be provided with two or more tubing inlets (sleeves) for different therapeutic agents, even one or more different gases such as oxygen, and agents to be mixed and delivered ultrasonically.
[0019] The catheter system of the invention is particularly advantageous on tissues for which local topical application of a therapeutic agent is desirable but contact with the tissue is to be avoided. Furthermore, ultrasound waves used in the method energize the drug, dissolve the clots and cause the penetration of the drug within the narrow and blocked vessels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is a perspective, partly cross-sectional view of an ultrasonic catheter drug delivery system for use according to the present invention;
[0021] [0021]FIG. 2 is a lateral view of an ultrasonic catheter system chamber of the invention with two horizontally located sleeves;
[0022] [0022]FIG. 3 is a frontal view of an ultrasonic catheter system chamber of the invention with three peripherally located sleeves;
[0023] [0023]FIG. 4 is a lateral, cross-sectional view of a catheter system chamber, mechanically coupled with an ultrasound transducer through the tip; and
[0024] [0024]FIG. 5 is a lateral, cross-sectional view of an ultrasonic catheter drug delivery system for delivering therapeutic agent to the catheter body or chamber through a central orifice of the ultrasonic tip.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention is a method and device, which provides treatment of luminal conditions, particularly for the treatment of coronary and peripheral arterial disease and thrombosis, where the purpose is to dissolve or disrupt the clot, plague or other stenotic lesions which cause the disease, and for dilation of narrowed vessels. The method and device of the present invention also useful to enhance the administration of therapeutic agents primarily responsible for the disruption of the clots or other stenotic material. The ultrasonic energy agitates and promotes the penetration of the drug into the stenotic material. Due to delivery of therapeutic agent and ultrasound energy through the agent, this method and device of the present invention are further useful for treatment of other body lumens, such as the urethra, ureter, fallopian tubes, or urological disorders related with prostate gland (BPH—Benigh Proctatic Hyperplasia), and can be used for impotency (erectile dysfunction) treatment by ultrasonically stimulating sexual organs, urinary tract, and the like.
[0026] The present invention can be used for targeted and localized drug delivery for treatment of lung, vasculature, vasopasm and tumor treatment. In addition, this invention is very useful for the treatment of closed wounds as a fistulas, canals, etc., by destroying bacteria cells and stimulating healthy tissue cells.
[0027] The invention can perhaps be better appreciated by referring to the drawings. FIG. 1 is a perspective view of ultrasound catheter drug delivery system 2 , comprising an ultrasound generator 4 , a connector 6 operatively connecting ultrasound generator 4 with a transducer 8 , a housing 10 surrounding transducer 8 , and a catheter 12 having a proximal portion 14 with a chamber 16 containing a therapeutic agent 18 . Transducer 8 has a tip 20 with a radial surface 22 and a distal radiation surface 24 . Chamber 16 is in fluid communication through tubing 26 with a fluid source 28 , and directly with at least one lumen 30 of the distal portion 32 of catheter 12 that extends to catheter distal end 34 . Fluid source 28 can be, for example, a reservoir with a pressure pump or syringe.
[0028] The proximal section 36 of catheter proximal portion 14 sealingly engages housing 10 . Preferably the inner surface 38 of proximal section 36 has threads 40 that engage reciprocal threads 42 on the outer surface 44 of housing 10 . This arrangement will allow the operator to vary the distance between distal radiation surface 24 and the distal end 46 of chamber 16 to regulate ultrasonic pressure and energy level. While radial surface 22 can be smooth or substantially smooth, it is preferred that this surface is not smooth, for example, with rings, threads, barbs, or the like, which will create more ultrasonic pressure in catheter 12 .
[0029] In the embodiment of the invention shown in FIG. 1, ultrasonic energy at a preselected frequency is sent through the catheter 10 with fluid such as a therapeutic agent as a transmission member. Ultrasound energy will pass through therapeutic agent 18 to catheter distal end 34 . Catheter 12 may be formed from a conventional rigid or flexible material, dependent upon the application. It would be appropriate for catheter 12 to be flexible if the catheter is to be inserted into tortuous vascularity or if catheter distal end 34 is to be attached to a vessel, fistula, or the like.
[0030] A second embodiment of the invention is shown in FIG. 2, where transducer 50 is fixedly, optionally removably, attached to the proximal section 52 of the proximal portion 54 of a catheter 56 . Transducer 50 has a tip 58 with a radial surface 60 and a distal radiation surface 62 . Catheter proximal portion 54 has a chamber 64 with a therapeutic agent 66 that is in fluid communication with each of two fluid sources 68 , 70 through lumens 72 , 74 , respectively. Fluid sources 68 , 70 may provide two or more fluids, e.g., liquid or gas, such as saline or oxygen, to be ultrasonically mixed and delivered through lumen 76 to catheter distal end 78 .
[0031] [0031]FIG. 3 is a semi-cross-sectional view of the proximal end of a catheter according to the invention wherein three fluid sources 80 are each in fluid communication through a lumen 82 with chamber 84 of catheter proximal section 86 . The distal radiation surface 88 of a transducer (not shown) is positioned within chamber 84 .
[0032] In FIG. 4, a connector 110 operatively connects an ultrasound generator (not shown) with a transducer 112 , which has a tip 114 with a radial surface 116 and a distal end surface 118 . A catheter 120 has a proximal portion 122 with a chamber 124 containing a therapeutic agent 126 . Chamber 124 is in fluid communication through tubing 130 with a fluid source 132 , and directly with at least one lumen 134 of the distal portion 136 of catheter 120 that extends to catheter distal end 140 . Fluid source 132 can be, for example, a reservoir with a pressure pump or syringe.
[0033] The proximal section 142 of catheter proximal portion 122 sealingly engages radial surface 116 . Chamber 124 must be attached to ultrasonic transducer distal tip 114 at the mechanical resonant node, such as node 144 . If chamber 124 is not connected to the resonant node (either a little before or a little after the mechanical node), the intensity of the ultrasound energy at distal end 140 will be attenuated, i.e., damped, and ultrasound waves and/or energy will be transferred to the walls of chamber 126 , possibly damaging the chamber 126 structure assembly, which may cause leakage.
[0034] In the embodiment of the invention set forth in FIG. 5, a connector 150 operatively connects an ultrasound generator (not shown) with a transducer 152 , which has a distal tip 154 with a radial surface 156 and a distal end surface 158 . A catheter 160 has a proximal portion 162 with a chamber 164 containing a therapeutic agent 166 .
[0035] Transducer distal tip 154 has a central orifice 170 . Chamber 164 is in fluid communication with at least one fluid source 172 through central orifice 170 , which can be smooth, waved, ringed, slotted, grooved, or threaded, and infusion lumen 174 within tubing 176 . Two or more fluid sources 172 and infusion lumens 174 can mix and deliver different therapeutic agents. Chamber 164 is also in fluid communication with lumen 180 in the distal portion 182 of catheter 160 that extends to distal end 184 . The non-smooth surface of orifice 170 , such as rings or threads, increases the pressure of liquid in chamber 164 .
[0036] Chamber 164 should be attached to ultrasonic transducer distal tip 158 at a mechanical resonant node, such as node 190 . Similarly, each lumen 174 should intersect central orifice 170 at a resonant node, such as node 192 .
[0037] The catheter systems herein are comprised of conventional materials. The transducer and catheter chamber are preferably comprised of suitable metallic or even polymeric substances. Most preferably the transducer distal tip is comprised of a metal such as titanium or nitinol.
[0038] As is mentioned throughout, the invention here can deliver one or more liquid or gaseous substances to a catheter distal end. Such substances include, but are not limited to, therapeutic agents such as antibiotics or antiseptics, saline, oil, water, oxygen, anticoagulants such as heparin or cumadine, or even liquid medical polymers, or mixtures of two or more thereof.
[0039] The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, however, that other expedients known to those skilled in the art or disclosed herein, may be employed without departing from the spirit of the invention or the scope of the appended claims.
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An ultrasonic catheter drug delivery device comprises an ultrasound transducer to produce ultrasonic waves, which transducer is mechanically attached to a catheter body or chamber. The ultrasonic transducer has a distal tip with a distal radiation surface, and when a therapeutic agent from a fluid source is directed to the catheter body or chamber, the radiation surface creates ultrasonic pressure and delivers liquid and simultaneously ultrasonic energy to a patient's vascularity or a selected body lumen. The method applies therapeutic agent and ultrasonic waves to the vascular area, lung or any body lumen without requiring direct contact between ultrasound transducer and body, dissolves blood clots, and stimulates tissue cells.
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BACKGROUND OF THE INVENTION
This invention relates to processes for the preparation of amido ethers and amino ethers by reaction of 2-oxazolines with alkanols. For a discussion of various known reactions of oxazolines see "Oxazolines. Their Preparation, Reactions, and Applications," John A. Frump, Chemical Reviews, Vol. 71, No. 5, pp. 483-505 (1971).
It is known that 2-alkoxyethyl amines can be prepared by reacting aziridines with alkanols under acidic conditions. Dermer and Ham, ETHYLENIMINE AND OTHER AZIRIDINES, Academic Press, pp. 224-6 (1969). It is also known that the corresponding N-(2-alkoxyethyl)alkanamides can be prepared by reacting such amines with alkanoyl chlorides. Morrison and Boyd, ORGANIC CHEMISTRY, 2nd ed., Allyn and Bacon, Inc., pp. 751-3 (1966).
SUMMARY OF THE INVENTION
This invention comprises a new process for the preparation of amido ethers and new processes for the preparation of amino ethers.
The new process for amido ether preparation is represented by the following equation: ##STR1## R is hydrogen or an alkyl radical containing from 1 to about 17 carbon atoms, each R' independently is hydrogen, methyl or ethyl and R" is methyl or ethyl.
This novel process comprises reacting by contacting, in liquid phase, an oxazoline (I) with methanol or ethanol (preferably methanol) in the presence of a catalytic amount of an alkali metal or derivative thereof.
To the best of our knowledge, reactions between 2-oxazolines and alkanols were unknown prior to our discovery.
The corresponding free amino ether (i.e., NH 2 --C(R') 2 --CH 2 --O--R") is prepared as a byproduct when the above process is conducted using excess alkanol. Alternatively, those amines are prepared by subsequent hydrolysis of the amido ether.
The above described amido ethers (III) are useful as intermediates for the preparation of the corresponding amino ethers.
The free amino ethers are useful acid scavengers and epoxy resin curing agents. For a discussion of the use of primary amines as epoxy resin curing agents, see HANDBOOK OF EPOXY RESINS, Lee and Neville, McGraw-Hill Book Company, Chapter 5 (1967). In addition such free amino ethers are useful as chemical intermediates for mining chemicals and for biocides for cutting oil preservation.
DETAILED DESCRIPTION OF THE INVENTION
This invention is a process for preparing amido ethers by contacting, in liquid phase, an oxazoline with methanol or ethanol (preferably methanol) in the presence of a catalytic amount of an alkali metal or derivative thereof.
The oxazolines useful in the practice of this invention are 2-oxazolines of the formula ##STR2## wherein R is hydrogen or alkyl of from 1 to about 17 carbon atoms, preferably hydrogen, methyl or ethyl, most preferably methyl or ethyl; and each R' independently is hydrogen, methyl or ethyl, preferably hydrogen. The compounds represented by I form a known class of compounds. Illustrative members of this class include: 2-methyl-, 2-ethyl-, 2-propyl-, 2-hexyl-, 2-nonyl-, 2-undecyl-, 2-heptadecyl- 2-oxazoline, the corresponding 4-methyl-2-oxazolines, 4-ethyl-2-oxazolines, 4,4-dimethyl-2-oxazolines, and the like.
2-Methyl- and 2-ethyl-2-oxazoline are the most preferred oxazoline reactants.
The alkali metals and derivatives thereof (i.e., catalysts) useful in the practice of the invention include lithium, sodium, potassium, rubidium, cesium, francium (preferably lithium, sodium and potassium) and derivatives thereof corresponding to the formula M + -OR'" wherein M is selected from the aforementioned group of alkali metals and R'" is hydrogen or alkyl of from 1 to about 4 carbon atoms, preferably R'" is methyl or ethyl.
Methoxides and ethoxides of lithium, sodium and potassium are the most preferred catalysts.
The catalyst is employed in the reaction in a small but catalytic amount, i.e. an amount sufficient to provide a measurable increase in the rate of reaction. The exact amount of catalyst can vary depending upon the reaction rate desired and the catalyst used. However, as a general rule, a satisfactory reaction rate is achieved when the catalyst is used in amounts between about 1 and about 50, preferably between about 10 and about 30, mole percent of the catalyst, based on the moles of oxazoline initially present.
The ratio of reactants (i.e., alkanol to 2-oxazoline ratio) may vary. However, the stoichiometry of the reaction makes it desirable that at least equimolar amounts of alkanol be used based upon the 2-oxazoline reactant. Naturally more than equimolar amounts of the alkanol may be employed. For example, utilization of excess alkanol is often advantageous in terms of increased reaction rates, improved yields, improved mixing, better heat transfer, and the like. Furthermore conducting the reaction in the presence of excess alkanol for prolonged durations (i.e., after the point at which no significant further increase in the amido ether product concentration is observed) results in the production of the corresponding amino ether as a reaction by-product; thus providing a convenient new means for preparing such amino ethers from 2-oxazolines.
The reaction temperature employed in the practice of the invention can be varied but convenient rates of reaction have been observed at reaction temperatures between about 100° C and about 225° C (preferably between about 150° C and about 170° C). At these temperatures, superatmospheric or autogenous pressure is generally employed to retain the reactants in the liquid phase.
The invention is preferably practiced under essentially anhydrous conditions. However, the total absence of water from the reaction mixture is not essential. Thus, for example, water introduced into the reaction mixture, whether as a contaminant of one or more of the reactants or as a by-product of the formation in situ of alkali metal methoxide or ethoxide from an alkali metal hydroxide and methanol or ethanol respectively, is not fatal to the successful practice of the invention. However, water present during the reaction serves to reduce the yield of the desired product by hydrolyzing approximately an equimolar amount of the 2-oxazoline reactant. It is therefore desirable that the water content of the reaction mixture be maintained as low as is practical.
The practice of the invention is further illustrated by the following examples.
Example 1
Preparation of N-(2-methoxyethyl)ethanamide from 2-Methyl-2-oxazoline and Methanol in the Presence of Sodium Methoxide.
In a one-liter stainless steel Parr bomb, 170 g (2 moles) of 2-methyl-2-oxazoline is mixed with 64 g (2 moles) anhydrous methanol. To this mixture is added a 13.5 g portion (0.25 mole) of sodium methoxide. The bomb is sealed and heated, with stirring, to 160° C for a period of 23 hours. The bomb is cooled and opened and the contents are suction-filtered through a glass fritted funnel, removing 16.3 g of previously suspended solid. This solid is washed with acetone and the washings are added to the filtrate.
The dark brown clear filtrate is vacuum distilled using a five-plate Oldershaw column equipped with a cold-finger condenser to give a light yellow, clear distillate overhead at a head temperature of 76.5° C/0.3 mm mercury. Distillation is terminated when the pot temperature reaches 185° C.
The light yellow distillate is verified to be N-(2-methoxyethyl)ethanamide via nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy and via mass spectrometry. The 165.2 g portion of the distillate recovered is found to be about 95 percent pure via gas chromatography and therefore represents a 67 percent yield based on the moles of 2-methyl-2-oxazoline initially charged.
Example 2
Preparation of N-(2-methoxyethyl)ethanamide and 2-Methoxyethyl Amine from 2-Methyl-2-oxazoline and Methanol in the Presence of Lithium Methoxide.
A 127.6 g portion (1.5 moles) of 2-methyl-2-oxazoline is mixed with 192.0 g (6.0 moles) absolute methanol and 11.4 g (0.3 mole) lithium methoxide in a one-liter stainless steel Parr reactor equipped with a turbine stirrer. The reactor is sealed and heated, with stirring, to between 160° C and 165° C and 220 psig. The reaction is continued under those conditions for a period of 23.5 hours. Samples are periodically taken from the reactor through a dip-pipe which is below the liquid level. Analysis of these samples by gas chromatography with an internal standard indicates that, at 60-75 percent oxazoline conversions, corresponding amide yields are very high (95-100 percent) based upon the amount of oxazoline converted. At higher oxazoline conversions, a significant by-product appears, which is identified as 2-methoxyethylamine. The concentration of this amine levels out, and at 96.4 percent methyl oxazoline conversion, an 82.3 percent yield of 2-methoxyethylacetamide and an 11 percent yield of 2-methoxyethylamine results. Thus, yields of amide and amine, based on a 96.4 percent oxazoline conversion, are 93.3 percent.
Example 3
Preparation of N-(2-ethoxyethyl)propanamide and 2-Ethoxyethyl Amine from 2-Ethyl-2-oxazoline and Ethanol in the Presence of Lithium Methoxide.
A 99.1 g portion (1 mole) of 2-ethyl-2-oxazoline is mixed with 184 g (4 moles) anhydrous absolute ethanol and 6.6 g (0.17 mole) lithium methoxide in a one-liter stainless steel Parr reactor equipped with a turbine stirrer. The reactor is sealed and heated, with stirring, to about 165° C. The reaction is continued under those conditions for a period of 36.5 hours. Samples are periodically taken through a dip-pipe which is below the liquid level. Analysis of these samples by gas chromatography at the end of the 36.5 hour reaction period indicates that about 43 percent of the 2-ethyl-2-oxazoline has been consumed. The yield of N-(2-ethoxyethyl)propanamide is found to be about 34 percent based upon the 2-ethyl-2-oxazoline charged to the reactor. The yield of N-(2-ethoxyethyl)propanamide based upon the amount of 2-ethyl-2-oxazoline consumed is found to be about 80 percent.
The reaction product also contains a small amount (about 0.07 mole) of 2-ethoxyethylamine. Thus the combined yield of amide and amine is about 41 percent based upon the 2-ethyl-2-oxazoline charged to the reactor and about 96 percent based upon the amount of 2-ethyl-2-oxazoline consumed.
While the present invention has been described with reference to particular embodiments and examples, it will be understood that these embodiments are not intended to limit the scope of the instantly claimed invention.
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N-(2-alkoxyethyl)alkanamides, such as N-(2-ethoxyethyl)ethanamide and N-(2-methoxyethyl)propanamide, are prepared by reacting a 2-oxazoline with methanol or ethanol in the presence of a strong base, such as sodium methoxide. Subsequent hydrolysis of such amides provides a convenient means for obtaining 2-alkoxyethyl amines.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of U.S. application Ser. No. 10/376,886 filed Feb. 28, 2003 now U.S. Pat. No. 7,118,560 by Jean M. Bonaldo for a NEEDLELESS LUER ACTIVATED MEDICAL CONNECTOR and assigned to the assignee of the present invention.
BACKGROUND OF THE INVENTION AND PRIOR ART
The present invention relates to connectors for use in medical flow lines for blood transfer, intravenous medication and nutritional supply, and the like. In accord with usual medical terminology, the connector may be referred to as having distal and proximal ends respectively designating the ends of the connector which are ordinarily positioned nearest and farthest from the patient.
U.S. Pat. No. 5,273,533 issued Dec. 28, 1993 and U.S. Pat. No. 5,306,243 issued Apr. 26, 1994 to Bonaldo each disclose a medical connector having an elastomeric element in the form of a septum or fluid barrier disposed in a two part plastic housing. The septum is pierced by a pointed cannula in the connector when making the connection to the fluid flowline. Disconnection of the flow line allows the elastomer to re-seal the connector. Repeated usage of such connectors may cause the connector to leak or become contaminated with particulate material such as particles which may detach from the septum. Repeated disconnection of the flowlines from the connector and decontamination of the connector and flowlines, as by swabbing with alcohol, is at least a daily occurrence. Thus, these connectors may be actuated or cycled many times and must remain leak free and reliably avoid introduction of contaminants such as cotton fibers from swabs used to clean the connectors into the flowline.
Medical connectors which use resilient flow barriers which are repeatedly pierced during use of the connector become more subject to fluid leakage with increased actuation cycles, particularly if connected in an infusion pump line which may subject the connector to pressures as high as 27 psi. U.S. Pat. No. 5,947,954 issued Sep. 7, 1999 to Bonaldo, the teachings of which are incorporated herein by reference, discloses a needleless connector which is addressed to the above concerns which includes attached relatively rotatable male and female Luer connector parts with an eccentrically positioned flow passageway at the inner end of the female Luer connector. A removable plastic plug, permanently attached to the connector by a strap, and which fulfills the function of a cleansing swab for the female Luer connector is also provided as an optional feature.
Although the removable plug when properly used closes the female Luer when the female Luer is not connected to a flowline, it has been found in practice that additional manipulation of the plug is required for proper use and that the plug can inadvertently become dislodged leaving the female Luer open to atmosphere and possible contamination. Accordingly, a more reliable and easy to use swabbable stopper for the female Luer part of the connector has been developed which always remains in proper position yet which also permits easy connection/disconnection of the male Luer end of a flowline to/from the connector valve is disclosed and claimed in a more recent U.S. Pat. No. 6,364,869 issued Apr. 2, 2002 to Bonaldo, the full teachings of which are also incorporated herein by reference. This stopper has an exterior end which essentially completely closes the otherwise open end of the female Luer when the connector is not in use to prevent introduction of fibers or other contaminants into the flow path in the connector. However, since fluid flow takes place along the outside of a stopper guide post mounted in the connector, it has been found that fluid may remain in the annular space between the post and inside wall of the swabbable stopper.
There remains a need to provide a further improved medical connector which includes a female Luer end having a swabbable elastomeric stopper which still further reduces the likelihood of contaminant entry to the fluid flow path. Also, there remains a need for a connector which has readily observable indicators thereon to enable the user to determine if the relatively rotatable parts of the connector are positioned to place the connector in the open or closed position.
Medical connectors are provided in fluid flowlines which ordinarily deliver blood, plasma or medication to a patient by gravity flow or with the assistance of an infusion pump. Often, when the medication in the container is exhausted, a pressure condition can be created by the patient's vascular pressure which results in retrograde flow of medication back from the patient to the flowline. Also, since it is frequently necessary to interrupt the flow of fluid to the patient as when changing the supplies of blood, plasma or medication or when it is necessary to draw blood from the patient, positive fluid pressure in the flowline which is ordinarily present is absent and undesired retrograde flow of blood from the patient into the flowline may take place. Retrograde flow is ordinarily prevented by inserting a separate one-way valve such as a duckbill valve, sometimes referred to as a heparin lock, in the flow line. Duckbill valves remain open under positive line pressure during delivery of flow to the patient but automatically close to prevent retrograde flow of medication and blood when delivery pressure is absent. The one-way valves used in the prior art, although effective for preventing retrograde flow, must be separately installed in the flowline and prevent the drawing of blood unless the one-way valve is removed from the flowline. Further improvements in medical connectors such as the connectors referred to in the above Bonaldo patents are desired to provide connectors having a self contained means of preventing retrograde flow of medication and blood and which permit the drawing of blood when desired.
SUMMARY OF THE INVENTION
Disclosed herein is a medical connector having a longitudinal axis and interconnected axially aligned relatively rotatable male and female Luer parts aligned to provide a housing whereby relative rotation of said parts opens and closes a fluid flow path through the connector, the parts being configured for connection to external male and female Luer flowlines. The device includes a fluidic channel insert, also referred to herein as a flow conducting insert, which is non-rotatably supported in the female Luer part. The insert has an internal fluid passageway extending from a first axially aligned end to a second end, said second end being offset from the connector axis. A compressible seal is positioned in the male Luer part and abuts the second end of the insert, the seal having a flow passageway extending between a first axially offset end at the second end of the insert to an axially aligned second end, such that said ends of said flow passageways in abutting ends of the insert and seal may be aligned to open a fluid flow path through the connector. An elastomeric stopper is mounted over the insert, the stopper having a swabbable end providing a deformable normally closed opening which may be opened when the swabbable end of the stopper is pushed over the end of the insert by an external male Luer received in said female Luer part. The stopper has an annular axially collapsible skirt engaged with the female Luer part and insert.
Also disclosed is a medical connector having interconnected axially aligned relatively rotatable parts forming a housing, the parts being configured for connection to external male and female Luer flowlines, a compressible seal in the housing having a flow passageway extending from an axially aligned end to an axially offset end whereby relative rotation of said parts opens and closes a fluid flow path through said connector; and a retrograde flow preventer positioned in the fluid flow path. The retrograde flow preventer is comprised of or includes a resilient member having a perforation which remains closed at patient vascular pressures to which an exterior surface of the preventer is exposed when flow, such as medication or blood, is not being delivered to the patient and which opens when an interior surface is exposed to flow pressures when administering medication or blood to a patent as by gravity or infusion pump pressures.
A swabbable stopper having a unique configuration is also disclosed and claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 comprises an exploded perspective view of the presently preferred embodiment of a medical connector according to the present invention including a contamination cap for a male Luer part;
FIGS. 2A and 2 b comprises a longitudinal cross-section views showing the medical connector of FIG. 1 with a swabbable stopper at the end of the female Luer part and with the connector in the closed position;
FIG. 3A is a view like FIG. 2A with the stopper end displaced from the FIG. 2A position by an external male Luer in a flowline and showing the connector in the open position;
FIG. 3B is a portion of FIG. 3A to a substantially enlarged scale;
FIG. 4 is a cross-sectional elevation of a female Luer housing part;
FIG. 5 is a left end view of the female Luer housing part;
FIG. 6 is a right end view of the female Luer housing part;
FIG. 7 is a cross-sectional elevation of a male Luer housing part;
FIG. 8 is a left end view of the male Luer housing part;
FIG. 9 is a right end view of the male Luer housing part;
FIG. 10 is a cross-sectional elevation view of the swabbable stopper;
FIG. 11 is a left end view of the stopper;
FIG. 12 is a right end view of the stopper;
FIG. 13 is a cross-sectional elevation view of the flow conducting insert;
FIG. 14 is a left end view of the insert;
FIG. 15 is a right end view of the insert;
FIG. 16 is a perspective view of a seal;
FIG. 17 is a left end view of the seal; and
FIG. 18 is a right end view of the seal.
FIG. 19 is a perspective view like FIG. 16 of a modified seal having a first form of retrograde flow preventer integrally formed therewith.
FIG. 20 is an end view of the modified seal of FIG. 19 .
FIGS. 21A and 21B are longitudinal cross section views of the modified seal taken at lines A-A and B-B of FIG. 20 , respectively.
FIG. 22 is a view like FIG. 2A showing a connector having the modified seal of FIG. 19 therein.
FIG. 23 is a perspective view of a second form of retrograde flow preventer.
FIG. 24 is an end view of the retrograde flow preventer of FIG. 23 .
FIG. 25 is a side view of the retrograde flow preventer of FIG. 23 .
FIG. 26 is a view like FIG. 2A showing a connector having the second form of retrograde flow preventer therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The medical connector 10 in which the present invention is used comprises essentially a five part connector comprising a housing formed by a male Luer configured part 20 connected to a female Luer configured part 30 with a cylindrical resilient seal 40 the outer edges of which are compressed between a valve seat 22 formed at the end wall in the male Luer part 20 and an end wall 32 of the female Luer part 30 . The male Luer part 20 and female Luer part 30 are aligned on a common longitudinal axis and are rotatable with respect to each other through an angle of preferably about 180° around the longitudinal axis to activate and deactivate the connector by opening and closing flow passageway through the connector. The female Luer part 30 includes a collar 31 having a face which abuts an end face of the male Luer part 20 , preferably along a transverse or radial plane. The collar 31 functions to block ingress of fluid which may be spilled during disconnection of an external male Luer 100 axially between the facing portions of the male and female Luer parts 20 , 30 since any spilled fluid ordinarily contacts the left end or side (as viewed in the drawings) of the female Luer 30 . The Exteriorly exposed surfaces adjacent the abutting faces are provided with visible or tactile indicia such as arrows 33 , 43 which may be aligned by relative rotation of the female and male Luer parts 20 , 30 to indicate the activated and deactivated, i.e., the full open and closed positions of the connector.
A longitudinally extending rib 37 inside the male Luer part 30 slides along a cam surface on the exterior of the right end of the female Luer part 30 and snaps into one of two axially extending cam grooves 27 on the exterior surface of the right end of the female Luer part when the Open and Closed indicia 33 , 43 are aligned at the full open and full closed positions of the connector. The grooves 27 and finger 37 are preferably configured as shown in FIGS. 6 and 8 with curved portions bounded by flat generally radially extending sides at the ends of the curved portions to assure proper full open and full closed relative positioning of the parts 20 , 30 . A concave gripping surface 21 on the male Luer part 20 may include elongated indentations or other roughening to facilitate fingertip gripping of the connector.
As seen in FIGS. 1-3 and 7 - 9 , the male Luer part 20 includes an internal flow passageway 24 in a frusto-conical Luer tapered male extension 26 and an internally threaded skirt 28 for connection to an external female slip or lock Luer in a flowline. The female Luer part 30 has an internal frusto-conical Luer taper at its left end as seen in the drawings and is also configured as a lock Luer externally threaded at 34 ; however, either or both of the Luer parts 20 , 30 can be configured instead as a slip or as a threaded lock Luer part. As shown, it will be apparent that the female Luer 30 is configured so that it may receive either an external male lock Luer or an external male slip Luer to make the fluid connection. Similarly, internal threads 29 are provided inside the skirt 28 of the male Luer part 20 so that it can be readily connected to either an external female lock Luer or an external female slip Luer.
The fluid flow passageway 24 in the male Luer part 20 extends longitudinally from the male extension part 26 to the valve seat 22 . The female Luer part 30 shown in FIGS. 1-3 and 4 - 6 , has an axially extending internal cavity 36 which may have an end portion 38 of non-circular configuration, for a purpose to be described.
The seal 40 (see FIGS. 16-18 ) has a generally cylindrical shape with a fluid flow passageway 44 extending from an axially aligned end 46 in fluid communication with passage 24 to an off-center positioned end 48 . The seal 40 is made of a firm but compressible elastomer, preferably silicone, the peripheral edge of which is preferably partially compressed between the valve seat 22 and the end wall 32 of the female Luer housing during assembly of the valve. The seal 40 has at least one and preferably three axially extending grooves 43 on its annular surface which mate with axially extending ribs 23 ( FIG. 8 ) in the male Luer part 20 to non-rotatably position the seal 40 in the male Luer part 20 . A longitudinally extending locating groove 45 is also provided on the annular surface of the seal 40 so that the seal 40 may be inserted into the male Luer part 20 along the finger 37 .
A male end Luer contamination cap 50 which may be made of polyethylene plastic, may be provided for enclosing the extension 26 of the medical connector during shipment or when not in use.
As seen in FIGS. 10-12 , a swabbable elastomeric stopper 60 having a normally closed end 62 and a depending corrugated skirt 64 is slidably mounted in the female Luer part 30 to normally close the open end thereof. A transversely extending slit 66 is provided through the normally closed end 62 of the elastomeric stopper 60 so that the slit can be opened when a male Luer end 102 of an external lock Luer 100 ( FIG. 3A ) engages the end 62 to push it over the end of a flow conducting insert 90 (to be described) when a flowline connection is made to the connector. It will be understood that the slit 66 may be a single transversely extending slit or two or more slits in form of a cross or any other functionally equivalent configuration such that the normally closed end 62 of the stopper 60 may be displaced as desired by the male Luer end 102 when a flowline connection is made. The stopper 60 also has an annular collar 68 which slidably engages the interior annular wall of the cavity 36 in the female Luer part 30 and a cylindrical end 69 which engages and seals off between the inside of the female Luer and the exterior of the insert 90 which also functions as a stopper guide.
FIGS. 13-15 show the fluidic channel insert or fluid conducting insert 90 , which may be made of polycarbonate, polypropylene, polyethylene or the like. The insert 90 may be integrally formed as shown or of multi-piece construction with a rigid or axially collapsible lumen having a central flow passageway 92 . Axial collapsibility of the insert 90 is preferably provided by making the insert 90 of polypropylene or polyethylene with flexible corrugations 98 near the heel 96 of the insert 90 . The corrugations 98 are not considered essential but, if provided, permit slight axial collapsibility of the insert 90 if contacted during activation by the end of an external male Luer 100 . This avoids force transmission by the insert 90 and undesired deformation of the seal 40 . Preferably the insert 90 is rounded at its left end as seen in the drawings for opening the slit 66 without damage. The flow passageway 92 axially extends from the left end of the insert 90 to an offset opening 94 in an end which provides a seat for the swabbable stopper 60 , the seat being hereinafter referred to as a heel 96 due to its non-circular configuration shown in the drawings, at the other end of insert 90 . The heel 96 is non-rotatably positioned in non-circular end portion 38 of the internal cavity 36 in the female Luer part 30 and is preferably restrained from axial sliding relative to the female Luer part 30 by an interference or press fit. Other complementary non-circular configurations of the heel 96 and end portion 38 can of course be chosen instead of the heel configuration depicted and those skilled in the art will appreciate that non-circular configurations, while preferred, are not essential.
Fluid flow is conducted through the connector from an external fluid flowline through the normally closed slit or slits 66 in the end wall 62 of the stopper which are displaced to the open position by engagement of the end wall 62 with an external male Luer 100 , the end 102 of which pushes the end 62 of the stopper 60 to the right as best shown in the enlarged scale FIG. 3B so that the end of the insert 90 opens the slit or slits 66 allowing fluid flow axially through the flow passageway 92 in the insert 90 to the offset opening 94 , then through the passageway 44 in the elastomeric valve element 40 to the passageway 24 in the male Luer extension 26 .
The resiliency and configuration of the skirt 64 of the swabbable stopper 60 are selected such that, during insertion of the external male Luer 100 into the female Luer part 30 , the end 102 of an external male Luer 100 first engages the end wall 62 of the stopper which in turn is pushed over the rounded end of the insert 90 with the end wall 62 folding and compressing between the end 102 of the external male Luer and the insert 90 to prevent fluid entry into the annular space between the stopper 60 and the insert 90 as seen in FIG. 3A . Note that the end of the external male Luer 100 also engages the end 62 of the stopper 60 to prevent fluid leakage to annular space between the stopper 90 and interior wall of the female Luer part 30 . The bellows portion of the skirt 64 between the collar 68 and the open end 69 of the skirt is compressed in the annular space between the inside wall of the female Luer part 30 and the outside wall of the insert 90 by engagement of at least some of the pleats of the bellows with the confining walls. It will be noted from viewing FIGS. 2A and 2B that the right end of the stopper 60 is also engaged with both the inside wall of the female Luer and the outside of the insert even when no flowline connection is made and when the end wall 62 of the stopper is flush with the end of the female Luer 30 .
It will also be noted that the stopper collar 68 preferably axially engages an internally projecting stop shoulder 35 inside the female Luer part 30 with some axial compression of the stopper skirt 64 to provide a slight pre-load, and that the open end 64 of the skirt continuously engages and is resiliently seated against the heel 96 on the insert 90 to retain the swabbable stopper in position. Also, the stopper 60 can be retained in position in the female Luer in any other suitable fashion, for example by adhesive bonding to the heel 96 of the insert 90 in which instance the skirt collar 68 and abutting shoulder 35 in the female Luer are unnecessary.
Axial pressure which may be exerted on the insert 90 during connection by the external male Luer 100 may slightly move the insert to the right as seen in FIG. 3 if the insert 90 is slidably fitted into the female Luer. This may serve to further compress the seal 40 whose outer edge preferably has already been slightly compressed by the end wall 32 of the female Luer part 30 during assembly into the male Luer part 20 . This compression of the seal may be avoided by use of the corrugations 98 on the insert 90 as described above. The Luer parts 20 , 30 are preferably connected together by a snap fit provided by a mating annular groove and collar depicted at 29 . The stopper skirt 64 may have what is described as a bellows or accordion like configuration as shown or it may be of sine wave or any other functionally equivalent configuration suitable for its intended purpose.
In the deactivated or closed position of the connector seen in FIGS. 2A and 2B , the bellows configuration of the skirt 64 of the stopper 60 urges the stopper end 62 outwardly of the female Luer part 30 so that the outer surface of the normally closed end 62 of the stopper 60 is substantially aligned or flush with the outer end of the female Luer part 30 . This position is assured by provision of the skirt collar 68 and its engagement with the stop shoulder 35 in the female Luer part 30 at the positions shown. This permits easy swabbing of the stopper whenever the flowline is disconnected from the connector and prior to the making of a new connection thereto.
Needleless medical connectors constructed as above described eliminate exposure to diseases such as hepatitis and HIV caused by needle sticks and are suitable in various medical flow lines low pressure gravity drips as well as highly pressurized fluid flow lines due to the relatively straight fluid flow path through the connector which substantially eliminate sharp bends and other internal flow restrictions in the fluid flow passageways 92 , 94 , 44 , 24 . The connector can therefore be safely used for gravity blood transfusions without concern that pressurization induced by an infusion pump may degrade delicate blood cells.
All dead annular space between the female Luer part 30 and the swabbable stopper 60 and between the swabbable stopper and the lumen of the insert 90 is sealed from fluid entry by engagement of the walls of the stopper 60 and the adjacent parts. This feature results in minimization of potential infections resulting from solid and bacterial contaminants from fluid which may collect or stagnate in dead space as well as reduction in the amount of fluid, such as expensive medication, required to prime the connector prior to activation since only the internal passageways 92 , 94 in the connector need be filled with priming fluid.
Negative pressure (suck back) upon disconnection of the external male Luer 100 is prevented simply by ensuring that the male and female Luer parts have been rotated to the Closed position prior to disconnection.
The connector may be made of clear plastic materials to enable visualization of the flow path and the parts may be readily injection molded and assembled without the use of ultrasonic welding or adhesives, swaging or additional fasteners of any kind.
FIGS. 19-21 depict a modified seal 40 , preferably of silicone, having a first form of retrograde flow preventer 110 integrally formed with the seal 40 . The retrograde flow preventer 110 is preferably formed as a thin protruding envelope 112 of the same resilient material of which the seal 40 is molded, preferably silicone. The envelope 112 has a fluid flow passageway therein which terminates in a normally closed transverse flow conducting slit 114 which automatically opens when the interior surface of the retrograde flow preventer 110 is exposed to normal pressures present when medication or blood is delivered by gravity or an infusion pump to the patient (the left to right direction in FIG. 19 ). The opposed broad sides of the envelope 112 of the retrograde flow preventer 110 are designed to automatically come together due to inherent resilience of the material from which they are molded to close the slit 114 whenever fluid delivery pressures are no longer present to prevent retrograde flow of medication or blood (right to left direction in FIG. 19 ) at patient vascular pressures.
Preferably, the envelope 112 is also designed to open by collapsing rearwardly into the fluid flow passageway 44 of the seal 40 when sufficiently high negative pressures are applied to the interior surface of the retrograde flow preventer 110 , as when using an aspirating syringe to draw blood from the patient. Other configurations of retrograde flow preventers 110 such as cylindrical, rectangular, conical or pyramid shape can also be integrally formed with the seal 40 and provided with any suitable configuration of flow conducting slit or slits or other perforations operable for the intended purposes.
By way of example and without limitation, the seal 40 may be formed of resilient elastomer such as clear silicone with the side walls of the envelope 112 having a wall thickness in the range of 0.10″-0.15″ and a length L ( FIG. 21B ) in the range of 0.030″-0.040″. The end wall through which the slit 114 is made may have a wall thickness of about 0.010″.
To receive the modified seal 40 and integral retrograde flow preventer 110 which protrudes from the modified seal 40 , a recess 116 , preferably cylindrical, is formed in the male Luer part 20 . Note that a clearance space 118 between the external sides of retrograde flow preventer 110 and the side wall of the recess 116 is provided. The clearance space 118 is intended to fill with retrograde flow of medication or retrograde flow of blood when medication is not being delivered to the patient so that the pressure of this fluid will be exerted on the external side of the envelope 112 to assist in keeping the slit 114 closed under these conditions
A second form of retrograde flow preventer 120 is depicted in FIGS. 23-26 . In this embodiment, the retrograde flow preventer 120 comprises a separate part preferably formed, at least in part, of resilient elastomer such as silicone or similar material. As with the first form of retrograde flow preventer, the preventer 120 may have the configuration of an envelope 122 having a transverse slit 124 or it may be of any other suitable configuration such as conical or pyramid configuration. The preventer 120 may have a rim 126 at its base which may be closely received in a seating groove 128 in the recess 116 . The retrograde flow preventer 120 functions in essentially the same manner as the first form of retrograde flow preventer 110 .
Negative pressure (suck back) upon disconnection of the external male Luer 100 is automatically prevented by use of either the first or the second form of retrograde flow preventers 110 , 120 described above even if the male and female Luer parts have inadvertently not been rotated to the Closed position prior to disconnection.
A further optional feature of the invention comprises the provision of a cam surface on the end of the female Luer part 30 such that rotation of the Luer parts 23 , 30 to the Closed position urges the seal 40 more tightly against its seat in the male Luer part 20 . One suitable form of achieving this result comprises a dimple 130 integrally formed on the end of the insert 90 in the position shown in FIGS. 13-15 . This feature is beneficial in squeezing the seal 40 into the clearance space 118 ro minimize the amount of fluid which would otherwise remain therein.
Prior to the use of needleless medical connectors, a typical clinical protocol would require the clinician to add a heparin lock to the IV system for “locking in” heparin at the end of a medication delivery so that a flowline would not clot off. this heparin protocol is still widely used today. The needleless Luer activated medical connectors disclosed herein with retrograde flow prevention are particularly beneficial since the prevention of retrograde flow eliminates the need for a heparin lock and permits a saline flush to be used after administration of medication rather than the typical heparin flush which many patients cannot tolerate.
While the foregoing constitutes a complete description of the invention, it will be appreciated by persons skilled in the art that changes and modifications of an obvious nature can be made from the illustrated embodiment and that such changes and modifications are considered within the scope of protection which is to be evaluated solely with respect to the attached claims.
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A medical fluid flowline connector comprised of axially aligned relatively rotatable male and female Luer parts and an axially compressible elastomeric seal therebetween. An elastomeric stopper may be provided in the female Luer, the stopper having a swabbable end urged outwardly of the female Luer. The stopper is guided on an axially extending elongated flow conducting insert which has an end which contacts a deformable slit in the swabbable end of the stopper to ensure deformation and opening of the slot as a male Luer at the end of a fluid flowline is pushed against the stopper. The stopper skirt is deformed and displaced into annular space between the female Luer and the insert, the stopper having bellows like walls which engage the female Luer and insert. A retrograde flow preventer may be positioned in the fluid flow path comprising a resilient member having a perforation which remains closed when its exterior surface is exposed to retrograde flow of medication or blood and which may open when its interior surface is exposed to sufficient negative flow pressures as when drawing blood.
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This is a divisional of application Ser. No. 09/583,376, filed May 30, 2000, now U.S. Pat. No. 6,360,413.
TECHNICAL FIELD
This invention relates to a ribbon curling machine and more particularly to both a hand operated ribbon curling machine and an automatic ribbon curling machine for producing a multiple curled ribbon decorative product where the ribbons overlie each other and are attached together. In some embodiments the curled ribbons are attached to a self sticking backing card or a bow or a display holding card or the like.
BACKGROUND OF THE INVENTION
As is known to those skilled in this technology, there are sundry ways in which to curl ribbon of the type that are typically used to decorate packages, flowers/cookie baskets and the like. One of the more arcane methods of curling is by sliding the ribbon over a knife-edge or any other object where the ribbon slides over a friction surface. For example the simple operation of sliding the ribbon over the edge of ordinary pair of scissors causes the ribbon, be it paper or plastic, to curl. This obviously has limitations, such as being slow, typically done for a single ribbon, and in the more common usage the practice was to curl the end portions of a typical decorative bow. Other types of curling has been done by hand-held curling tools as those described In U.S. Pat. Nos. 5,400,452 granted on Mar. 28, 1995; 5,564,145 granted on Oct. 25, 1996; 5,407,417 granted on Apr. 18, 1995 to Fredric Goldstein, one of the joint inventors of this patent application. Obviously, like the scissors described above, the curling tools disclosed in the immediately aforementioned patents all would require tedious curling and assembly of the curled ribbon strands.
In more recent years, the curling of the ribbon has become automated where a drawing apparatus draws the ribbon to be in frictional engagement with an edge to impart a curl to the ribbon and stripping mechanism that permits the mass production of the curled ribbon which can then be utilized for different types of applications. Examples of this type of mass produced curled ribbon is disclosed in U.S. Pat. Nos. 5,518,492 granted on May 21, 1996, 5,711,752 granted on Jan. 27, 1998 and 5,916,081 granted on Jun. 29, 1999 to Fredric Goldstein, a co-inventor of this patent application.
Also, we are aware of other machines that has the ability of making a curled product that has certain similarities to the end product of this invention and is made by an entirely different method. In one instance, a reciprocal sliding mechanism includes a clamp that holds a ribbon while it is drawn over a stapling device. The ribbon is laid over itself to form a stack of curled ribbons and a stapling device staples the ribbon to a backing card and the cycle is repeated.
This invention is primarily concerned with the curled ribbon that is packaged in one or a number of configurations including the configuration as shown in FIG. 1 of this patent application (curly ribbon). As noted therein, this curled ribbon ribbon product has four (4) curled ribbons 2 each of which are stapled in the center via staple 4 . This makes eight (8) strands of curled ribbons 3 emanating from staple 4 . Obviously, when a given length of ribbon is attached intermediate the ends of the ribbon by a staple, the portions of the ribbon emanating from the staple forms two (2) strands. In this end curly ribbon product card 5 and ribbons 2 are stapled together. The card which is designed to hang in a display rack may include one surface (not shown) coated with a glue and a paper cover that is removable to uncover the glued surface for sticking to a package and the front surface may include indicia, such as a logo, price, etc. Obviously, in other embodiments the card may be replaced by or made complementary to other devices or objects such as a bow, ribbon, string etc. It obviously should be understood that the FIG. 1 end product is simply one example of an end product of a curly ribbon product. The end product could include as many strands as desired, and it is typical that more than eight (8) strands are formed to make-up the end product.
In one embodiment of this invention, the apparatus for making this product is portable and hand-operated and in an other embodiment of this invention, the product is automatically produced. It will be appreciated that in both embodiments, the ribbon is wrapped around a drum or rotor as it is rotated about an axis either by hand or a motor and that at discreet locations on the drum are provided mechanism for clamping the ribbons onto the drum, stapling the ribbons and card together and cutting the ribbons in another appropriate location. Obviously, the curled ribbon for some decorative purposes are affixed at an intermediate portion and for others they are affixed at the end.
In one preferred embodiment of this invention, a hand operated drum, reel or disk (hereinafter referred to as a drum) mounted for rotation and includes a handle attached to the drum for causing the rotation. This embodiment also includes a number of posts for holding a number of spools of ribbon, an equal number of guide posts for each of the spools, an equal number of curling heads where the ribbon is placed in frictional engagement or contact to impart the curl thereto and a single guide post where all the ribbons are accumulated in such a manner that a portion of the ribbon is laid over other portions to form a stack to allow clamping with a single clamp. The drum includes stations to hold the combined ribbons with the use of an alligator clamp, and predetermined stations, one to staple the ribbons together and another to cut the ribbons. A card holder mechanism may be employed at the stapling station where the ribbons and card are simultaneously stapled together.
In another embodiment of this invention, an automated machine mass produces the entire package automatically once the machine is initially threaded. In this embodiment and according to this invention, a clamping mechanism including a pair of jaws judiciously clamps the then curled ribbon to the drum after being curled, the clamp releases the processed ribbon once the drum grasps the ribbons and sequentially re-clamps the next to be processed ribbons to continuously and cyclically produce an entire finished product. Also in accordance with this invention, this automated machine judiciously staples and judiciously cuts the curled ribbons in the proper sequence to produce the end product.
The advantages of utilizing a drum as taught by this invention and without limitation are as follows:
1) the drum provides a compact drive system, more compact than heretofore known systems, making it possible to have a machine which requires minimal space, and in the portable unit, it can fit on an ordinary kitchen table or the like;
2) the strands are inherently stacked together in the process of being pulled, unlike sets of wheels which would have to guide the 12 strands, for example, upon each other, which is critical when stapling or attaching the ribbon strands to a card;
3) the drum obviates the need of sets of wheel or roller drive systems and the necessity of synchronizing the wheels and rollers in these types of systems and avoids the potential of “looping”;
4) the drum, obviously, can increase the number of strands simply by increasing the number of revolutions in a cycle;
5) because the ribbon wraps around itself on the drum the ribbon eventually secures itself to the drum and the clamp for originally clamping ribbon to the drum is released. Thus the drag on the drum is reduced as the rotation continues. This obviates the problems of adverse release and tearing of the ribbon in heretofore known systems. and
6. the system using the drum always ends in the starting position for the next set of strands avoiding the necessity of repositioning the mechanism to begin the process.
In another aspect of this invention, the amount of curl can be controlled by selecting the proper discharge angle that the ribbon makes relative to the surface where the curl is imparted. Typically, the more acute the angle and hence the amount of drag or friction imparted to the ribbon as it is makes contact with the member imparting the drag or friction, the greater the degree of curl in the ribbon. This is the case no matter what the material the ribbon takes. This feature significantly allows the user to decide the overall size and shape of the curled ribbon product, whereby acute angles provides a more compact curled bow while lesser acute angles provides larger more flowing curls. When producing the curled ribbon product by an automated machine the curling device of this invention allows for consistency and flexibility in production.
SUMMARY OF THE INVENTION
An object of this invention is to fabricate a curled ribbon end product either manually or automatically by winding a plurality of ribbons around a rotating body and simultaneously imparting a curl thereto and then affixing the ribbons to another member and cutting the ribbon at different locations on the rotating body.
A feature of this invention is to provide a hand operated machine for making curled ribbons and attaching a plurality of ribbons taken from spools of ribbons to a clip or bobbin that is inserted into a rotatable drum that is rotated about an axis as by a handle mounted on the drum to draw the ribbons over a curling mechanism and which drum includes different stations for stapling the ribbons to each other and/or a card and for cutting the curled stapled ribbons.
Another feature of this invention is to provide a machine for automatically curling ribbons, attaching the curled ribbons to the drum of the machine, stapling the curled ribbons together at one station of the drum and cutting the ribbons at another station of the drum for producing a decorative piece. It will be appreciated that unless the ribbon upstream of the cutting or severing device is clamped prior to cutting, the ribbon will become disengaged from the drum and disrupt the cycle.
Another feature of this invention is to provide a curling device for imparting a curl to the ribbon that includes mechanism for changing the exit angle that the ribbon makes with the curling mechanism to control the curl characteristics of the ribbon.
Another feature of this invention is to provide a clamp that comprises automated fingers or jaws that are Controllable to temporally clamp, release and re-clamp a plurality of ribbons wound around a rotating drum.
Another feature of this invention is to provide an automatic machine for mass producing decorative curled ribbons by curling each of a number of ribbons and then combining and processing the combined ribbons through a number of sequential operations including the steps of winding the plurality of ribbons around a drum after being curled, affixing the curled ribbons to a card having a glued backing with the use of an automatic card feeding and stapling mechanism, an anvil, separately cutting the assembled card and curled ribbons that are attached to the card and releasing the assembled unit from the machine.
Another object of this invention is the method for producing a decorative multi-colored curled ribbon end product from a continuous supply of different colored uncurled ribbons including the steps of combining the different colored ribbons, stapling and cutting thereof.
Another feature of this invention is to provide a method that cyclically produces a curled ribbon product by the steps of providing a rotating drum, a clamp for clamping a plurality of ribbons which may be of different colors to a the drum until the ribbons are self-supported to the drum and then releasing the clamp from the ribbons, re-clamping the plurality of ribbons, affixing the ribbons together and then cutting the affixed ribbons in one cycle so as to provide a continuous process for mass producing the end product without the necessity of manually feeding the machine after the initial feed.
A still further object of this invention is to teach a system for making curled ribbon product that is characterized as being simple and inexpensive to use and manufacture as well as affording the following advantages:
1) a compact drive system, more compact than heretofore known systems is attained, making it possible to have a machine which requires minimal space, and in the portable unit, it can fit on an ordinary kitchen table or the like;
2) the strands are inherently stacked together in the process of being pulled, unlike sets of wheels which would have to guide the 12 strands, for example, upon each other, which is critical when stapling or attaching the ribbon strands to a card;
3) it obviates the need of sets of wheel or roller drive systems and the necessity of synchronizing the wheels and rollers in these types of systems and avoids the potential of “looping”;
4) it increases the number of strands simply by increasing the number of revolutions in a cycle;
5) because the ribbon wraps around itself on the drum the ribbon eventually secures itself to the drum and the clamp for originally clamping ribbon to the drum is released. This obviates the problems of adverse release and tearing of the ribbon in heretofore know systems; and
6. the system always ends in the starting position for the next set of strands avoiding the necessity of repositioning the mechanism to begin the process.
The foregoing and other features of the present invention will become more apparent from the following description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing one version of the decorative curled ribbon after being processed;
FIG. 2 is a perspective view of the hand operated curl making machine of this invention;
FIG. 2A is a schematic view of the embodiment depicted in FIG. 2;
FIG. 3 is a view in perspective and schematic illustrating a portion of the automated machine of this invention;
FIG. 4 is a schematic illustration of the various stations on the drum and the actuation mechanisms associated with each of the stations for the automated machine of this invention;
FIG. 5 is an isometric exploded view illustrating the details of the curling mechanism of this invention;
FIG. 6 is a side view and schematic illustration of the curling mechanism of FIG. 5 illustrating the exit angle that the ribbon makes relative to the curling mechanism that can be changed to change the curling characteristic of the ribbon;
FIG. 7 is a partial view in perspective illustrating the clamping and cutting stations of this invention.
FIG. 8 a is a schematic illustration of the various stations on the drum and the actuation mechanisms associated with each of the stations for the automated machine of this invention where the drum is at a given location for one of the functions of the cycle;
FIG. 8 b is a elevated view of the a portion of the drum at one of the stations illustrating the position of the clamp and ribbons at the location of FIG. 8 a;
FIG. 9 a is identical to FIG. 8 a illustrating a different location of the drum at a different function of the machine during the cycle of operation;
FIG. 9 b is identical to FIG. 8 b illustrating the a different position of the clamp and ribbon at the location of FIG. 9 a;
FIG. 10 a is identical to FIG. 9 a illustrating a different location of the drum at a different function of the machine during the cycle of operation;
FIG. 10 b is identical to FIG. 9 b illustrating the a different position of the clamp and ribbon at the location of FIG. 10 a;
FIG. 11 a is identical to FIG. 10 a illustrating a different location of the drum at a different function of the machine during the cycle of operation;
FIG. 11 b is identical to FIG. 10 b illustrating the a different position of the clamp and ribbon at the location of FIG. 10 a;
FIG. 12 a is a partial view partly in section, partly in elevation and partly in schematic illustrating the anvil and stapling mechanism of this invention in the deployed position;
FIG. 12 b is identical view of FIG. 12 a illustrating the staple and anvil in the non-deployed position;
FIG. 13 is a plan view of the card feeding mechanism of this invention;
FIG. 14 is a block diagram showing the various actuators within the drum and the medium for actuating these actuators; and
FIG. 15 is a block diagram showing the various actuators outside of the drum and the medium for actuating these actuators.
These figures merely serve to further clarify and illustrate the present invention and are not intended to limit the scope thereof
DETAILED DESCRIPTION OF THE INVENTION
While the invention in its preferred embodiment utilizes a particularized curling mechanism and stapling card it is be understood as one skilled in this art will recognize that this invention contemplates utilizing any type of curling mechanism and the stapling can be to any object such as a bow and the stapling can include other means of attaching the ribbons together and/or attaching objects thereto such as by fusion or adhesives or pinning or card locking or the like. It is also to be understood that the shape and/or configuration of the drum can take any form so long as it rotates about an axis and is capable of supporting the ribbons around the periphery thereof. As one skilled in this art will appreciate, the length of the strands are determined by the circumference of the drum and obviously, the length of each strand will be predicated on the circumference selected for the drum. For example a drum whose circumference is 38 inches (approximately 12 inches in diameter) will produce a curled ribbon that is 38 inches long and hence each strand will be 19 inches long.
The invention with respect to the hand operated embodiment can best be understood by referring to FIGS. 2 and 3. The portable hand operated curling machine generally illustrated by reference numeral 10 comprises the generally flat base 12 supporting a plurality of upstanding stub shafts or spindles 14 for supporting spools of ribbons 16 . In this instance, three spools of uncurled ribbons are shown, but it is to be understood that any number of spools can be utilized and the number of ribbons selected to form the curled ribbon end product is a matter of choice of the user. A complementary guide spool 18 for each of the spindles 14 are disposed between the curling mechanism 20 that is affixed to the base and the curling drum 26 for guiding the ribbon through the respective curling mechanism 20 . The curling mechanism will be described in detail hereinbelow. Each of the guide spools 18 are loosely fitted on a support spindle 22 affixed to base 12 . These guide spools 18 are free to rotate and afford substantially little if any resistance to the ribbon as is travels through the machine 10 . Another single guide spool 24 similarly attached to a support spindle affixed to base 12 and also loosely fitted to freely rotate is mounted between the curling mechanism 20 and the curling drum 26 and guides the three (3) ribbons in an overlapping configuration.
The curling drum 26 is rotatably supported to a stub shaft 28 affixed to base 12 and rotates thereabout by virtue of the movement of the handle 30 . Essentially the curling drum 26 consists of at least three stations, namely, the attachment or clamping station 32 , the cutting station 34 , and the stapling station 36 . The attachment station 32 , the cutting station 34 and the stapling station 36 are slots or holes and slots that extend through the width of the drum 26 or at least a sufficient distance to perform the functions as will be described immediately below and are formed adjacent the periphery of the drum 26 . The distance between the cutting station 34 and the stapling station 36 determines at which point the ribbons will be attached to each other. As shown in this embodiment the curled ribbons are being attached at their respective ends. To attach the ribbons at another point, for example, the cutting slot 34 a is formed at cutting station 34 a . At this station the ribbon will be attached intermediate the ends and will form a decorative curled ribbon as shown in FIG. 1 .
In operation, each of the uncurled ribbons 16 are threaded and clamped through the respective curling mechanism, then laid adjacent to the respective guide spools 18 and then laid adjacent to the single guide spool 24 and the ends of the ribbons are held together in the overlapping position by the commercially available alligator clamp 38 which, in turn, is inserted by the operator into the aperture formed in the drum at the attachment station 32 . This secures the ribbons to the drum 26 . The operator with the use of the knob 40 affixed to handle 30 , rotates the drum 26 a number of revolutions until the desired end product is achieved, i.e. the number of curled ribbons constituting the end product is obtained. For example, if two (2) revolutions of the drum are made with three uncurled ribbons and the cut is 180° away from the staple station, the end product will include twelve (12) strands of curled ribbon emanating from the staple. On the other hand, if the cut is adjacent to the staple station, the number of strands of curled ribbons will be six (6), albeit twice as long. With an ordinary, commercially available stapler (not shown) with the base fitted into the slot 34 a and the hammer head of the stapler straddling the ribbon, the staple is inserted into the ribbons. The stapling station 36 may include a wedged shaped portion 37 on either side of the slot which is designed to hold a card adjacent to the curled ribbons and in this instance the card is concomitantly stapled to the ribbons as shown in FIG. 1 . The operator next, with the use of commercially available scissors (not shown) inserts the blades of the scissors to straddle the ribbons and snips the ribbons to produce the end item. Obviously, the ribbons can be cut with any other well known device, such as a knife or razor. The curled ribbons as processed by this portable curling machine produces the decorative piece as the end item which is ready for use to decorate a package, basket and the like. Obviously, from the foregoing it is easy to understand that the machine is so simple to operate that it is usable by practically all persons, is portable and sufficiently small and light weight to be easily stored.
The next portion of this application will describe the automated curling machine generally indicated by reference numeral 50 . Like the drum described in connection with the hand operated curling machine depicted in FIG. 2, this automated machine 50 also includes a drum that wraps the ribbon around the periphery thereof and the drum includes stations for clamping the ribbon, stapling and cutting the ribbons as will be described hereinbelow. Before describing the entire machine, it is noted that the curling mechanism shown in FIGS. 5 and 6 is substantially the same as the curling mechanism utilized in connection with the machine depicted in FIG. 2 and for the sake of convenience and simplicity this curling mechanism is being described at this point in the disclosure.
In its preferred embodiment the curling mechanism generally indicated by reference numeral 52 generally consists of two (2) generally cooperative flat plate elements 54 and 56 . Obviously, any type of mechanism that imparts a frictional force when the ribbon is moved in contact therewith that produces a curl can be employed. This particular mechanism has been selected because the exit angle can be changed so as to control the degree of curl in the ribbon as will be explained in more detail hereinbelow. The plate 54 may include a dowel pin 58 that fits into the drilled hole 60 to prevent the plate from rotating and a bolt 62 that fits through hole 64 formed in plate 56 and is threaded to the complementary threads 66 formed in the bore 68 to support the plates together leaving a small gap for allowing the ribbon to pass therebetween. The leading edge 70 of plate 54 is rounded to minimize the friction between that edge and the ribbon passing thereover and the portion 72 adjacent the bottom edge of the plate 56 is recessed and beveled to define a blade-like element where the ribbon comes into contact therewith as it is drawn thereover. A like configuration is provided on the diametrically opposed side to allow either side of the plate 56 to be used.
As shown in FIG. 6 the ribbon as depicted by the arrow A is threaded over the curved surface of plate 54 and passes between plates 54 and 56 and then over the edge 74 of the recessed portion 72 and led away therefrom as indicated by arrow B. In these embodiments there is virtually no tension in the ribbon upstream of the curling mechanism 52 , save for the amount needed to allow the ribbon to progress through the machine and most of the tension on the ribbon occurs between the edge 76 and the drum. By virtue of this arrangement, the curling mechanism 52 can be oriented to change the angle C formed between the plate 56 and the ribbon. The angle C that is selected will determine the curvature of the curl in the ribbon. In other words, a more acute angle will impart a more severe curl and a less acute angle, i.e. an angle closer to 90 degrees will impart a larger diameter curl.
In addition to the curling mechanism, as described above, the automated machine as best seen in FIG. 3 includes the rotating drum 80 with specific stations (similar to those depicted in FIG. 2 ), namely, the ribbon clamping station 82 , the cutting station 84 and the stapling station 86 . The ribbons are similar to FIG. 2 mounted on the base 86 and includes a slotted upstanding member 81 that guides each of the ribbons into the curling mechanism 52 , the guiding spools 83 and 85 also similar to that shown in FIG. 2 . The base 88 supporting the drum 80 for rotary motion is supported in an upright position by a suitable cabinet 90 so that when the end product is completed it will fall by gravity to the bottom. The card feeding mechanism 92 which is sequentially placed in position at the stapling station may be pivotally mounted to swing radially outward away from drum 80 after the stapling so that after being cut in the cutting station 92 it will avoid being snag or tangled with the machinery. It will be apparent that the ribbon may or may not be curled at the initial load-up, i.e. when first loaded onto the clamp, but thereafter, as the drum begins its rotation, the ribbon is curled as it is pulled over the curling mechanism 52 .
The actuators for controlling the function at the various stations of the drum during operation of the machine are supported internally of the drum in this embodiment and the actuators for controlling the card feeding and card cutting mechanisms are located away from the central portion of the drum and will be described in detail herelinbelow. A control panel generally illustrated by reference numeral 93 mounted on the machine includes suitable commercially available switches that serve to turn on and off the machine, to override the automatic sequence of the machine's functions which are controlled by a central processing unit 94 , that sequences the rotation of the drum, controls the various actuators both internal and external of the drum and the electric motor 96 , as will be explained hereinbelow. The main control for the machine is a special digital computer including a programmable logic controller unit (PLC) that serves to control the sequencing operations of the machine. The control panel may contain control buttons for jogging the rotational position of the drum, permitting individual actuation of the actuators so as to allow the initial threading of the ribbons, to initiate the automatic and continuous operation of the machine and may include an emergency stop. The PLC is commercially available, as for example, from the Mitsubishi Company of Japan and is of the type that can be programmed which is typically done by a computer programmer to perform the necessary functions as needed.
FIGS. 4, 7 a , 7 b , 8 a , 8 b , 9 a , 9 b , 10 a and 10 b , illustrate schematically the details of the machine excluding the card feed and card cutting mechanisms. As noted therein the drum 80 at the clamping station 100 and cutting station 102 is flattened and this flattened portion 103 has disposed adjacent thereto the jaws 104 and 106 and the cutting blade 109 . Actuators 108 , 110 , 112 and 114 serve to control the position of jaws 104 and 106 . Actuator 108 serves to rotate jaw 104 , actuator 110 serves to rotate jaw 104 , actuator 112 serves to position jaw 104 radially outwardly relative to jaw 106 and actuator 114 serves to position both jaws 104 and 106 radially outwardly together with respect to the drum 80 .
This portion of the description will describe the operation of the clamping mechanism and referring next to FIG. 7, the flattened portion 103 at clamping station 82 includes a recess portion 120 for receiving the jaws 104 and 106 and the partially annular groove 122 partially extending around the circumference receives and guides the first layer of the six (6) curled ribbons. As noted the jaws are in the clamped position in this FIG. 7 . In the initial threading of the machine and before clamping this layer of curled ribbons between the jaws 104 and 106 , these jaws are positioned radially outwardly relative to drum 80 and jaw 104 is positioned radially outwardly with respect to jaw 106 providing a gap to accept the curled ribbons (noting that in this embodiment that each layer includes six (6) curled ribbons). Once the clamp is threaded, the jaws are brought together and retracted into the recess portion 120 to clamp the ribbons, and the initial layer of ribbons rides in groove 122 by virtue of actuating the electric servo motor 96 to rotate drum 80 . After the drum has rotated one or more revolutions depending on the number of strands that are required to make up the desired end product the clamping mechanism will be activated to release the layers of ribbons constituting the end product and re-activated to capture the layer of ribbons for the next cycle of operation so as to mass produce the end product. For example and for explanation purposes, assume that the end product will contain twenty-four (24) strands of curled ribbons emanating from the staple, noting that the cutting of the ribbon is 180° away from the stapling station, the drum will make two revolutions (each revolution of the layer of six (6) ribbons makes 12 strands relative to the staple). After the first revolution and when the second bundle of six curled ribbons overlay a portion of the first bundle of six curled ribbons, the combined underlayer and over layer will hold the ribbons to the drum without the assistance of the clamping mechanism. This portion of the machine's operation is shown in FIGS. 8 a and 8 b where it can be seen that the underlayer is clamped between the jaws and the over layer lies over the jaws.
At this juncture point of the machine operation the jaws are actuated to perform a sequence of moves so as to clamp the next layer of six (6) ribbons to be ready for the next cycle. One cycle produces one end product. While the drum is rotating the cylinders 112 , 108 and 110 are actuated to open the jaws and rotate the jaws downwardly below the ribbon path. This permits the jaws to release the underlayer of ribbons and to be moved away from the path of the ribbons drawn over the drum 80 . Cylinder 114 is then actuated to position the jaws 104 and 106 away from the drum. This is demonstrated in FIGS. 9 a and 9 b.
Before the completed revolution of the second layer of ribbons and during the first cycle, the lower jaw 104 is rotated back in the path of the ribbon by cylinder 110 as seen in FIGS. 10 a and 10 b . After the portion of the second layer of ribbons passes over the lower jaw 104 the cylinder 108 is actuated to bring the upper jaw 106 in line with the lower jaw 104 and the cylinder 112 is activated to bring both jaws together and clamp the ribbon as seen in FIGS. 11 a and 11 b . The jaws 104 and 106 are held radially outwardly away from drum 80 until after the cutting and stapling occurs and the next cycle commences.
This portion of the description describes the cutting and stapling operation of the automatic curled ribbon making machine. After the clamp secures the bundle of ribbons to begin the next cycle, the motor is activated to the stop position. While it isn't necessary to stop the rotation of the drum since it is possible to perform the next operations while the drum is moving, in its preferred embodiment the stapling and cutting is done while the machine is at rest. To perform the cutting operation, cylinder 140 is actuated to rotate the blade 142 extending through an aperture 144 formed in drum 80 . Blade 142 is pivotally connected to drum 80 by the pin 146 and the reciprocating action of the connecting arm pivots the blade 142 to cause it to cut through the ribbon.
Obviously, it is necessary to staple or join the respective layers of six ribbons prior to the cutting operation and this portion of the description describes the stapling operation of the machine. The stapling is accomplished in the preferred embodiment by a commercially available industrial type of cartridge feed stapler 146 which may be a Swingline stapler obtained from Swingline Inc. of Long Island City, N.Y. As best seen in FIGS. 12 a and 12 b the stapling is done at the stapling station 86 which similar to the cutting and clamping stations is a flattened portion 152 of the periphery of drum 80 . Stapler 146 includes a hammer 154 actuated by cylinder 156 that urges the continuous feed staple 158 toward the anvil 160 that causes one of the staples to pass through the ribbon and card 162 to secure all the individual ribbons and card together to form the end product. The raising and lowering of the anvil 160 is controlled by the cylinder 166 that pushes the pivoted links 188 and 200 via push rod 204 to cause the Y-shape to an I-shape to drive the anvil block 202 up and down.
The automatic card feeder 220 as best shown in FIG. 13 serves to automatically feed the cards 222 between the anvil 160 and staple 154 (FIGS. 12 a and 12 b ). The cartridge of cards is feed to the feeder 220 and the cards are urged toward the anvil 160 via the actuator 224 until properly located. The commercially available rotary cutter 226 and cylinder 228 serve cut the card after being stapled to the ribbons. The automatic card feeder 220 is mounted to the base 88 (FIG. 3) adjacent to the drum 80 by the actuator 230 and push rod 232 which supports the automatic card feeder 220 for pivotal movement away from drum 80 once the card is attached to the ribbon and held by the automatic card feeder 220 . Once the end product is spaced away from the drum 80 the card is cut and released from the card feeder 220 and allowed to drop into a suitable carton or conveyor belt as the case may be. If necessary, a blow off nozzle or as many as need be may be employed to assure that the strands of ribbons, which are essentially free floating from the card, does not become ensnared with the mechanism.
To understand the medium for controlling the various function of the automated curled ribbon curling machine and the interconnection between the various components reference will now be made to block diagram configuration of FIG. 14 . In this diagram all of the solid lines represent electrical connection, all of the dash lines represent pressurized air feed hoses connections and all of the dot/dash lines represent feedback connections to the PLC. The PLC produces sequential signals to the individual commercially available solenoid valves generally indicated by reverence numeral 240 . Each cylinder is connected to the air manifold which is connected to a supply of pressurized air by virtue of opening and closing the respective solenoid valves to actuate and de-actuate the respective cylinder. Cylinder 108 actuating jaw 104 , cylinder 110 actuating jaw 106 , cylinder 140 actuating the cutter 142 and cylinder 166 actuating the anvil 160 are commercially available compressed air actuated actuators and suitable actuators of this type, for example are Clippard Cylinders available from the Clippard Instrument Laboratory, Inc. Of Cincinnati, Ohio. The cylinder 156 actuating the stapler and the cylinder 112 actuating the jaws to cause them to separate are also commercially available compressed air actuator and a suitable actuator is a Festo pneumatic actuator available from the Festo Inc. Of Hauppauge, N.Y. The cylinder 114 actuating both jaws together is also a compressed air actuator and a suitable actuator is a Fabco-Air available from Fabco-Air of Gainesville, Fla. The card feed actuator cylinder 224 and the rotary cutter cylinder 228 are also commercially available and a suitable actuator is a Bimba, available from Bimba Manufacturing Company, Monee, Ill.
It is apparent from the foregoing that the PLC will generate sequential signals to cause the various solenoid valves 250 , 252 , 254 , 256 , 258 , 260 , 262 and 264 to interconnect or disconnect the compressed air from a suitable source 290 to feed each of the cylinders through the respective hoses 270 , 272 , 274 , 276 , 278 , 280 , 282 and 284 to perform the functions as was described in the above paragraphs. The blowoff nozzle 292 is shown and as noted above is utilized to assure that the end product doesn't become ensnared with the operating mechanism of the curled ribbon machine and is only used as needed. Feed back sensors for the cutter 142 , stapler 146 and anvil 160 serve to feed back the position of each cylinder to the PLC via the lines 294 , 296 and 298 .
FIG. 15 is a block diagram similar to FIG. 14 but showing the functions that are not on the drum namely, the card feed cylinder 224 , the swing arm cylinder 230 , and the card cutter cylinder 226 . The solenoid valves 310 , 312 and 314 are controlled by the PLC and serve to connect the compressed air to the cylinders 224 , 230 and 226 via the air hoses 316 , 318 and 320 , respectively, for providing the respective functions. Feedback for the positions of these respective cylinders are fed back to the PLC through lines 322 , 324 and 326 , respectively. The PLC likewise controls the on/off and position of the motor via the motor driver 338 and encoder 340 . Each of the ribbons are provided with a break sensor 300 that is connected to the PLC via the feed back line 302 .
What has been shown by this invention is different embodiments of a machine for making curled ribbon products, say a multicolored multiple ribbons formed into a plurality of strands of curled ribbon, either individually or by mass production. The individual making is by a portable hand operated machine that includes a drum or reel for winding the ribbon and drawing it through a curling mechanism, where the drum includes stations for attaching the ribbons to the drum, stapling the ribbons and a card or other item together, and cutting the ribbons to form the desired end product. In the mass production machine, the stations are formed on the periphery of the drum and the attaching is by a judiciously sequenced clamping mechanism and a automatic stapling mechanism that accepts cards from an automatic card feeding mechanism so as to staple the ribbons and card together and discretely positioned the end product away from the drum when releasing the end product from the machine.
Although this invention has been shown and described with respect to detailed embodiments thereof it will be appreciated and understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.
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In one embodiment a hand operated machine for making curly ribbon products comprises a rotary drum that includes a station to attach the uncurled ribbons (more than one), a cutting station to cut the curled ribbons, and a stapling station to staple the ribbons together or to a card, ribbon, or the like. A handle is provided to rotate the drum and a fixed curling mechanism mounted downstream of the drum serves to curl the ribbon as the drum rotates to place the ribbon in contact with the curling mechanism. In another embodiment the machine is automated and includes a drum that has the same stations. The attaching station includes a pair of jaws that are sequentially movable one relative to the other and together to attain attaching the ribbons to the drum for the first cycle, detaching the ribbon during the first cycle and attaching the succeeding ribbon used in the next cycle for mass producing the curly ribbon product. The stapling and cutting are automatic and the card feeding machine is movable relative to the drum to avoid snarling the ribbon when released. The curling mechanism is adjustable to change the exit angle to select the desired curl characteristics of the curled ribbon.
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TECHNICAL FIELD
The present invention relates generally to a radar system and a method of generating waveforms for use by the radar system. More particularly, the present invention relates to an impulse radar system that generates individual pulses of a pulsed waveform from spectral components having frequencies that vary between individual pulses.
BACKGROUND OF THE INVENTION
Radar systems generally require bandwidth in order to resolve targets, i.e., the larger the bandwidth, the higher the range resolution. Conventional radar systems use waveforms with long pulse width and typically have an instantaneous bandwidth on the order of 100 MHz. To improve the instantaneous bandwidth, exploration has been done in connection with impulse radars. Impulse radars use a train of short pulses on the order of 200 picoseconds and have been shown to have an instantaneous bandwidth on the order of 5 GHz.
In the past, impulse radars have taken the approach of switching the RF transmit signal on and off in picoseconds in order to generate the train of extremely short pulses. However, such systems generally require the impulse generator to have a peak power on the order of several megawatts due to the fact that it has a low duty factor in that the pulse width of the impulse generator is extremely short when compared to the required interpulse period.
In an effort to ameliorate these problems, the inventor of the present invention explored an ultra-wide bandwidth radar that used a specified set of narrow band spectral components to synthesize a waveform with very high range resolution. This concept, which was embodied in U.S. Pat. No. 5,146,616 (the '616 patent) and U. S. Pat. No. 5,239,309 (the ' 309 patent), was implemented by combining (summing) multiple continuous wave sources having frequencies that were equally spaced. This superposition of continuous wave sources resulted in the desired repeating pulse train without the need for fast switching circuits. However, the waveform described in the aforementioned patents required that the transmitted sources be evenly spaced across at least a portion of the available frequency spectrum.
Recently, a need has been expressed for a radar system that could operate in the communication bands, e.g., from 3 Mhz to 1 GHz (covering HF, VHF, and UHF bands). Such a radar would be quite useful, particularly since it would have superior foliage penetration to radars operating at microwave frequencies and above. Unfortunately, the impulse radars of the prior art, including those covered by the '616 patent and the '309 patent, would not be suitable for such operation. Specifically, the prior art impulse radar systems are likely to interfere with communication signals being transmitted in the band of operation of the radar.
Therefore, it would be advantageous to have a radar system that could operate in the communication bands without interfering with other users transmitting within these bands.
SUMMARY OF THE INVENTION
The present invention provides a radar system that uses a wide bandwidth pulsed signal that is composed of spectral components having frequencies spaced at irregular intervals. Specifically, the present invention provides a radar system that is capable of varying the frequencies of the spectral components composing individual pulses of the pulsed signal so as to avoid interfering with ongoing communications within the radar's transmission band.
In accordance with one aspect of the present invention, a radar for locating and tracking objects based on the use of a pulsed waveform, each pulse of the pulsed waveform being made up of a plurality of spectral components having different frequencies is provided. The radar includes an antenna and a transmitter operatively coupled to the antenna for generating the plurality of spectral components that make up each pulse of the pulsed waveform. The radar further includes a receiver operatively coupled to the antenna for receiving signals at the frequencies of the plurality of spectral components and a signal processor operatively coupled to the receiver for processing the received signals in order to generate and output a radar presentation and to detect the presence of other signals at particular frequencies. The signal processor is operatively coupled to a display for displaying the radar presentation. Finally, the radar includes a controller operatively coupled to the transmitter and the signal processor for varying the frequencies at which the plurality of spectral components are generated, such that the transmitter generates spectral components at frequencies different from the frequencies of other signals detected by the signal processor.
In accordance with another aspect of the present invention, a radar is provided wherein the controller suppresses the generation of those spectral components having frequencies that are the same as the frequencies of the other signals detected by the signal processor.
In accordance with still another aspect of the present invention, a radar is provided wherein the spectral components are produced at frequencies within a frequency band of between approximately 20 MHz and approximately 600 MHz.
In accordance with still a further aspect of the present invention, a method of generating a pulsed waveform having a plurality of spectral components is provided. The method includes the steps of listening across a predetermined frequency band in order to determine which frequencies within the frequency band are available for transmission and generating for a finite period of time a plurality of spectral components having frequencies corresponding to at least a portion of the frequencies available for transmission. The method further includes the steps of combining the plurality of spectral components into a pulse of the pulsed waveform, transmitting the pulse of the pulsed waveform, and repeating the prior steps to generate and transmit a plurality of subsequent pulses of the pulsed waveform.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified block diagram illustrating a radar system in accordance with the present invention.
FIG. 2A is a frequency domain representation of uniformly frequency spaced continuous wave sources, which when summed together create the pulsed waveform illustrated in FIG. 2 B.
FIG. 2B is a time domain representation of the pulsed waveform created by summing the continuous wave sources represented in FIG. 2 A.
FIG. 2C is a frequency domain representation of eleven logarithmically frequency spaced continuous wave sources, which when summed together create the pulsed waveform illustrated in FIG. 2 D.
FIG. 2D is a time domain representation of the pulsed waveform created by summing the continuous wave sources represented in FIG. 2 C.
FIG. 2E is a frequency domain representation of sixteen logarithmically frequency spaced continuous wave sources, which when summed together create the pulsed waveform illustrated in FIG. 2 F.
FIG. 2F is a time domain representation of the pulsed waveform created by summing the continuous wave sources represented in FIG. 2 E.
FIG. 3 is a simplified block diagram of a digital implementation of a radar system in accordance with the present invention.
FIG. 4 is a schematic illustration of an analog implementation of one channel of a radar system in accordance with the present invention.
FIG. 5 is a flow chart illustrating the steps performed by a radar system in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail with reference to the drawings. In the drawings, like reference numerals are used to refer to like elements throughout.
FIG. 1 is a block diagram representation of a radar system 10 in accordance with the present invention. The radar system 10 includes an antenna 12 coupled to a plurality of switches 14 a - 14 n. The switches 14 a - 14 n are of the single-pole double-throw variety and operate to connect electrically the antenna 12 to both a series of transmitters 16 a - 16 n and a series of receivers 18 a - 18 n. The transmitters 16 are driven by a common master oscillator 20 and are connected to a master controller 22 , the function of which will be described in more detail below. The master controller 22 is also connected to the switches 14 and a signal processor 24 . In turn, the signal processor is connected to both the receivers 18 and a display 26 .
Referring now to FIGS. 2A-2F, the waveforms generated by the radar system 10 will be discussed in more detail. For simplicity, the discussion will be confined to a frequency band between 50 MHz and 550 MHz, although any frequency band could be used without departing from the scope of the present invention. FIG. 2A is representative of 11 continuous wave (CW) sources 40 of equal amplitude but uniformly spaced in frequency across the frequency band. These 11 CW sources 40 make up the spectral components of the waveform represented in FIG. 2 B. As discussed previously, it was found that when these 11 sources were summed together, the result was a waveform having a strong central peak 42 with noisy time-domain side lobes 44 mirrored about the central peak 42 .
As is shown in FIGS. 2C-2H, a similar waveform is generated when summing or combining CW sources that are not uniformly spaced in frequency. FIG. 2C illustrates 11 CW sources 46 , which are logarithmically spaced in frequency. As is illustrated in FIG. 2D, when these sources 46 are combined, the resulting waveform contains a strong central peak 48 with noisy time-domain lobes 50 mirrored about the central peak, although the time-domain side lobe structure does differ from the side lobe structure illustrated in FIG. 2 B. Similarly, when 16 tones or CW sources are combined that are logarithmically spaced in frequency (See FIG. 2 E), a waveform similar to the waveform illustrated in FIG. 20 (see FIG. 2F) is generated. As is readily seen, the time-domain side lobes 52 are of lesser amplitude than the time-domain side lobes 50 illustrated in FIG. 2 D. It should be noted that as the number of tones or CW sources used to generate the transmitted waveform is increased, the relative strength (amplitude) of the time-domain side lobes decreases as compared to the central peak (See FIGS. 2 D and 2 F).
Ultimately, the inventor of the present invention determined that there need not even be a mathematical correlation for the frequencies of the tones or CW sources combined to generate a waveform that could be used by the radar system 10 . The tones could be randomly spaced in frequency and the resulting waveform would still contain a strong central peak with noisy time-domain side lobes mirrored thereabout. The only requirement is that the tones used to generate the waveform be derived from a common master oscillator, i.e., that the tones be mutually coherent.
Referring back to FIG. 1, the basic operation of the radar system 10 will be described. As is the case with all radar systems, radar system 10 operates in both a transmission mode and a receive mode. To transmit a signal, the master controller 22 places switches 14 a - 14 n in an appropriate position to connect electrically the antenna 12 and the transmitters 16 a - 16 n. The transmitters 16 each act as a single CW source. Each signal produced by the transmitters 16 is coherently generated from the master oscillator 22 and provided to the antenna 12 . In this embodiment of the present invention, each signal is generated for a period of 0.33 milliseconds, although other generation time periods could be used if an application required a longer pulse train. In other words, the “on” time of the transmitter 16 corresponds to the pulse duration for each individual pulse in the pulsed waveform.
The antenna 12 , which is preferably a broadband multiplexing antenna, receives the signals generated by the transmitters 16 and combines them into a high gain beam. The master controller 22 controls the “on” time of the transmitters 16 . After the “on” time has expired, the master controller 22 shuts down the transmitters 16 and shifts the switches 14 a - 14 n into the appropriate position for the radar system 10 to act in a receive mode.
On receive, the antenna 12 separates all of the spectral components of the incoming waveforms. The spectral components are then coupled to the plurality of receivers 18 a - 18 n. The receivers 18 , the operation of which will be described in more detail below, each provide an output to the signal processor 24 , which coherently combines and processes the outputs in order to produce a signal that is provided to the display 26 , thereby creating a radar presentation. In this embodiment, the radar system 10 functions in the receive mode for a period of 50 milliseconds. Generally, the “off” time for the transmitters will correspond to the range of the radar system 10 . Specifically, the “off” time should be sufficient to ensure that all return pulses have been received, thereby negating the potential for antenna 12 to receive and transmit simultaneously.
As was discussed above, the number or density of the spectral components combined in order to create the pulsed waveform influences the strength of the time domain side lobes of the pulsed waveform in comparison to the central peak. Therefore, if the spectral components are densely frequency spaced, the pulsed waveform reduces to a single transmitted impulse without side lobes. Although such a waveform may be ideal, it is not necessary to achieve the benefits of the present invention. For example, the present radar system 10 can be effective when using 20 to 40 spectral components.
Turning now to FIG. 3, a digital implementation of the radar system 10 is illustrated. The radar system 10 includes a broadband multiplexing antenna 60 electrically connected to a single-pole double-throw switch 62 . The switch 62 is illustrated electrically connected to a receive path 64 . However, the switch 62 will toggle between the receive path 64 and a transmit path 66 in response to commands from a master controller 68 .
When toggled into connection with the transmit path 66 , the switch 62 couples the antenna 60 to a digital transmitter 70 . In the illustrated embodiment, the digital transmitter 70 is in communicative relation with both a memory 72 , which stores digitally synthesized waveforms, and a master oscillator 74 , which functions as a master clock for the radar system 10 . In response to commands from the master controller 68 , the digital transmitter 70 selects the appropriate waveform for transmission.
As will be discussed in more detail by reference to FIG. 5, the waveform will be selected based upon the spectral components available for transmission, i.e., those spectral components that will not interfere with other communication ongoing within the transmission band of the radar system 10 . The memory 72 may contain digital representations of the actual waveforms to be transmitted. Alternatively, the memory 72 may contain digital representations of individual spectral components. In this case, the digital transmitter 70 would select the appropriate spectral components from the memory 72 and digitally synthesize therefrom the waveform to be transmitted.
When toggled into connection with the receive path 64 , the switch 62 couples the antenna 60 to a direct sampling receiver 76 . The direct sampling receiver 76 samples received signals in order to generate data that will be used by a digital signal processor 78 which is coupled to the direct sampling receiver 76 . In this embodiment of the present invention, a sample rate of 1 gigasample per second would be sufficient to capture information on the received signals.
As is the case with conventional radar systems, the digital signal processor 78 processes the information provided by the direct sampling receiver 76 in order to generate a radar presentation that the digital signal processor 78 then provides to a display 80 .
Referring now to FIG. 4, the present invention, if desired, could also be implemented in analog circuitry. FIG. 4 represents an analog implementation of one channel or tone of the present invention. One skilled in the art will appreciate that this implementation will be repeated for each channel of the radar system 10 . To the extent practical, certain of the components may be common to each such channel.
As with the digital implementation described above, an antenna 90 is coupled via a switch 92 to both a transmit path 94 and a receive path 96 . When connected to the transmit path 94 , the switch 92 couples the antenna 90 to a transmitter 98 that is controlled by a controller 99 . The transmitter 98 is driven by a frequency synthesizer 100 so as to create a spectral component having a particular frequency. As was discussed previously, it is desirable that each CW source be coherently generated. Accordingly, the frequency synthesizer 100 is connected to a master oscillator 102 , which synchronizes the generation of the CW sources for all channels of the radar system 10 .
When connected to the receive path 96 , the antenna 90 is coupled to an RF amplifier 104 to detect and amplify spectral components of the received signals. The RF amplifier 104 is connected to a mixer 106 , which mixes the output signal of the RF amplifier 104 with a signal from the frequency synthesizer 100 . The signal from the frequency synthesizer provided the mixer 106 is offset in frequency from the signal the RF amplifier 104 provides the mixer 106 by an amount equal to the frequency of the master oscillator 102 .
The mixer 106 outputs a signal to an intermediate frequency amplifier 108 , which provides an amplified output to both in-phase mixer 110 and quadrature mixer 112 . In-phase mixer 110 and quadrature mixer 112 mix the amplified output with a signal from the master oscillator 102 and provide respective outputs to an in-phase A/D converter 114 and a quadrature A/D converter 116 .
The in-phase A/D converter 114 and the quadrature A/D converter sample the outputs from mixers 1 10 and 112 and provide I and Q data to a digital signal processor 118 for use in creating a radar presentation. In accordance with the Nyquist criterion, the A/D converters 114 and 116 must sample at a sufficient rate to capture available information from the received signals. Generally, a sampling rate of 8 kHz would be adequate in the present embodiment of this invention.
Referring now to FIG. 5, the operation of a radar system in accordance with the present invention will be described. In step 200 , the system commences operation and, in step 202 , initially determines the frequencies within the frequency band of the spectral components that will form a pulse of the pulsed waveform. The frequencies could be static or dynamic. In other words, the system could be built such that it included a plurality of transmitters (on the order of 20 to 40), each transmitter designed to generate a continuous wave signal at a predetermined frequency. Alternatively, the system could be designed such that the frequencies at which the transmitters generate the signal vary based upon information received from other components in the system.
In step 204 , the system is set to operate in the receive mode, and listens across at least a portion of the frequency band in which the system is designed to operate in order to detect the presence of signals at the same frequencies as the desired frequencies for the spectral components. If the system detects the presence of signals at the desired frequencies, the controller will send a signal to the applicable transmitters, thereby suppressing the generation of that spectral component (see step 206 ). Then, as indicated in step 208 , the system is switched to the transmit mode and the remaining spectral components, i.e., the spectral components having frequencies not conflicting with other signals within the operational range of the radar system, are transmitted.
As discussed previously, eliminating one or more of the spectral components that make up a pulse results in an increase of the relative strength of the time-domain side lobes as compared to the main lobe, thereby degrading the “quality” of the pulse. This degradation is generally quite slight and should not impact adversely the operation of the radar system. However, as opposed to suppressing one or more of the spectral components, the system could be configured to provide a predetermined number of spectral components, the frequencies of which vary from pulse to pulse based upon the frequencies within the band available for transmission. This “frequency hopping” would reduce both the likelihood of repetitively being unable to transmit and the ability of a third party to jam this radar system.
In step 210 , the signal that is transmitted by the antenna is recorded and stored for use by the signal processing electronics. In step 212 , the system switches back to the receive mode and listens for the return signals. The return signals that are received are provided to the signal processor and correlated against the transmitted signal, as recorded. The basic purpose of the correlation function is to match the received signals to the transmitted signal. As is indicated in steps 214 and 216 , the information generated by this “matching” is used to create the impulse response or “A-scope” response of the radar system, which is in turn used in a conventional manner to generate the radar presentation or display.
The correlation of the received to the transmitted signal may be complicated by the Doppler shift created in the returned signals. One potential method of addressing such complication would be to correlate the received waveform against a plurality of trial Doppler-shifted transmitted waveforms, using the results of such correlations to create the impulse response of the radar system.
Steps 202 through 216 are then repeated to create subsequent pulses of the pulsed waveform. Generally, it is anticipated that each pulse will be made up of a superposition of spectral components having frequencies that vary from the frequencies of the spectral components making up one or more of the previous pulses. In this manner, a radar system is provided which employs a signal having spectral components that will not interfere with other communication signals being transmitted. Thus, the present system can be employed in any frequency bands including communication frequency bands. Furthermore, because the spectral components of each pulse will likely vary, a radar system is provided which is very difficult to jam since any jamming scheme will need to know exactly which frequencies will be received by the system at a precise point in time.
Although the invention has been shown and described with respect to certain embodiments, it is obvious that equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification.
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A radar for locating and tracking objects based on the use of a pulsed waveform, each pulse of the pulsed waveform being made up of a plurality of spectral components having different frequencies, including an antenna. The radar further includes a transmitter operatively coupled to the antenna for generating the plurality of spectral components that make up each pulse of the pulsed waveform and a receiver operatively coupled to the antenna for receiving signals at the frequencies of the plurality of spectral components. The radar also includes a signal processor operatively coupled to the receiver for processing the received signals in order to generate and output a radar presentation and to detect the presence of other signals at particular frequencies, a display operatively coupled to the signal processor for displaying the radar presentation, and finally a controller operatively coupled to the transmitter and the signal processor for varying the frequencies at which the plurality of spectral components are generated, such that the transmitter generates spectral components at frequencies different from the frequencies of other signals detected by the signal processor.
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FIELD OF THE INVENTION
The present invention relates to a transformer; and, more particularly, to a transformer capable of adjusting an inductance tuning range of its inductors without decrease of the capability of the inductors by selectively connecting the inductors with switches attached thereto to thereby control an amount of magnetic flux.
DESCRIPTION OF RELATED ART
In FIG. 1A , there is provided a circuit diagram of a conventional planar type variable inductor, which includes serially connected two inductors and a switch connected in parallel to one of those inductors.
In case that the switch is not connected, a whole inductance value becomes L 1 +L 2 and, if otherwise, the whole inductance value changes to L 2 . That is, the variable inductor can have two kinds of inductance values.
FIG. 1B is a circuit diagram of a conventional stack type variable inductor, which includes three inductors stacked up vertically and switches connected between the three inductors. In this case, according to the status of switches, it is possible to implement the variable inductor, which has various inductance values such as L 1 +L 2 +L 3 , L 1 +L 2 , L 1 +L 3 , L 1 , and so on, in a small area. And a range of the variable inductance can be changed continuously.
However, in general, since the conventional variable inductor described above is implemented by connecting many inductors serially and connecting the inductors with switches in parallel and the number of working inductors and a whole inductance value are determined according to the connecting status of the switches, the conventional variable inductor has a problem of deteriorating the whole inductor's capability.
That is, the conventional variable inductor has a limitation in terms of an area and performance. In other words, effects of switches and a large area due to serially connected inductors raise a large area problem. To overcome this problem, when stacking up inductors, it is possible to reduce the area. However, it still brings a problem in decreasing performance of the variable inductor.
In addition, in case of the conventional variable inductor, the great loss, which comes from an electric resistor or capacitor of a switch connected to an inductor can decrease the whole inductor's capability.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a transformer capable of adjusting an inductance tuning range of its inductors without decrease of the capability of the inductors by selectively connecting the inductors with switches attached thereto to thereby control an amount of magnetic flux.
In accordance with an aspect of the present invention, there is provided a transformer, having a multiplicity of inductors formed on a semiconductor substrate, for varying an inductance value, which includes N number of metal lines, N being a positive integer, and N number of ports made by twisting the metal lines in the form of a symmetric circuit, wherein a certain number of ports among the N number of ports, which are connected to switch elements.
A more complete appreciation of the present invention and its improvements can be obtained by reference to the accompanying drawings, which are briefly summarized below, to the following detail description of presently preferred embodiments of the invention, and to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:
FIG. 1A shows a circuit diagram of a conventional planar type variable inductor;
FIG. 1B is a circuit diagram of a conventional stack type variable inductor connecting inductors vertically;
FIG. 2A presents an equivalent circuit diagram of a 2-port variable inductor using a transformer in accordance with the present invention;
FIG. 2B describes an equivalent circuit diagram of 1-port variable inductor using a transformer in accordance with the present invention;
FIG. 3A depicts a transformer capable of adjusting the number of inductor's windings for each port in accordance with the present invention;
FIG. 3B illustrates a transformer having four ports in accordance with the present invention;
FIG. 3C provides a transformer having four ports in a planar and stack structure in accordance with the present invention;
FIG. 4A describes a 4-port transformer in a planar structure for varying the number of windings for each port in accordance with the present invention;
FIG. 4B shows a 4-port transformer in a planar and stack structure for varying the number of windings for each port in accordance with the present;
FIG. 5A presents a 2-port transformer having a variable inductor with switches connected thereto in accordance with the present invention; and
FIG. 5B is a 1-port transformer having a variable inductor with switches connected thereto in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Other objects and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter.
The present invention relates to a variable inductor using the structure of a transformer. In general, a transformer consists of two ports. However, in the present invention, it is possible to increase the number of ports by twisting metal lines on a plane or by stacking up two metals. That is, according to the number of metal layers and twisted metal lines on a plane, it is capable of determining the number of ports. And the number of winding metals for each port can be determined according to a desired inductance value.
In order to control magnetic flux by using the transformer structure, it is practicable to produce a variable inductor by connecting switches to ports desired to control to thereby add or deduct an inductance value of each port to or from the whole inductance value.
The difference of the present invention from conventional ones is using a method of adding or deducting an amount of magnetic flux of an inductor of each port instead of using a method of removing an inductor itself from a signal flow. Therefore, there is no attenuation of a signal due to switches. Moreover, a very wide range of variation of inductance can be obtained.
The present invention relates to an element usable as a variable inductor by using a transformer, which can be used in CMOS RF ICs (Integrated Circuits). It is possible to get characteristics of broadband by using an advantage of varying inductance and applying it to a circuit used in RFIC.
A transformer structure, which is symmetric, can be classified into a planar type and a stack type, and can be implemented in 2-port, 3-port, or 4-port according to the desired form.
The present invention mainly explains the concept of a 4-port variable inductor. The basic concept is fixing an inductance value of one port among four ports to a desired value, and then by using the remained three ports, it changes inductance through varying an amount of magnetic flux generated by an electric current in each port.
The three ports have switches connected thereto and, by controlling opening or closing the switches, it can be possible to turn on electricity among the three ports selectively. It is also possible to selectively control the direction of an electric current and make the direction reversely in natural. If the electric current goes reversely, the direction of magnetic flux should be in reverse as well, resulting in the whole inductance changed to decrease.
FIG. 2A shows an equivalent circuit of a 2-port variable inductor using a transformer in accordance with the present invention. Except ports 1 and 2 among four ports, switches 1 and 2 are connected to the remained two ports, ports 3 and 4 , so that it is capable of controlling an amount of magnetic flux flowing the inside diameter by adjusting the connection of the switches.
A signal inputted from the port 1 moves to the port 2 , and in this case, the inductance of the port 1 is changed by the ports 3 and 4 . That is, it is possible to find an optimized inductance value for ideal movement of signals by tuning the inductance of the port 1 .
FIG. 2B presents an equivalent circuit diagram of a 1-port variable inductor by using a transformer in accordance with the present invention.
In this case, except a port 1 among whole four ports, switches 1 , 2 and 3 are connected to ports 2 , 3 and 4 , respectively and control an amount of magnetic flux.
An inductance value of the port 1 can be tuned by the other ports. This structure has a transformer structure, but it works simply as an inductor in a symmetric structure and can have a wide range of varying inductance values.
FIG. 3A depicts a transformer having a 2-port transformer structure by twisting metal lines in order to control the number of winding metals for each port.
In general, it is possible to make a 1:1 type transformer, but this structure is also applicable to the implementation of a 1:n transformer on a plane.
FIG. 3B illustrates a 4-port transformer in accordance with the present invention, which has a 1:1:1:1 ratio for number of windings for each port.
Since it is formed on a plane instead of in a stack type, area increases, however, it has an advantage of implementing many ports.
FIG. 3C is a structural diagram of a 4-port transformer in a planar and stack structure in accordance with the present invention. In order to overcome a disadvantage of the 4-port transformer formed in a planar structure as presented in FIG. 3B , the structure having four ports is implemented by stacking up two 2-port planar structures.
In this case, it also has a 1:1:1:1 winding ratio. In particular, in this structure, according to which process is used, the total number of metals is determined. As the number of metals increases, the number of ports is also increases.
FIG. 4A describes a 4-port transformer in a planar structure varying the number of windings for each port in accordance with the present invention. There is provided a structure capable of varying the number of windings for each port in a 1:n:m:k ratio instead of 1:1:1:1 in FIG. 3B .
FIG. 4B presents a structural diagram of a 4-port transformer, which is made by stacking up the 2-port transformer presented in FIG. 3C and consists of a planar structure and a stack structure for varying the number of windings for each port.
FIG. 5A shows a structural diagram of a 2-port transformer having a variable inductor with switches connected thereto and FIG. 5B presents a structural diagram of a 1-port transformer having a variable inductor with switches attached thereto.
In FIGS. 5A and 5B , the inductance can be varied by connecting the switches to the 4-port transformer presented before.
FIG. 5A is a drawing of practically implementing the 2-port transformer designed in FIG. 2A with a stack structure and uses general NMOS switches as the switches.
Similarly, FIG. 5B is a drawing for practically implementing the 1-port transformer described in FIG. 2B by connecting the switches to the three ports in order to thereby change the inductance.
The concept of making variable inductance is simple, however, various explanations for its implementation can be possible and ideal performance can be achieved by the inductance tuning.
Therefore, in accordance with the present invention, it is possible to adjust an inductance value without affecting a signal flow directly by using a transformer structure and, in addition, it is capable of controlling an inductance value arbitrarily according to a transformer structure.
Additionally, because switches do not lie on a signal path, a variable inductor having a transformer structure has no decrease of performance due to the switches and no limitations on account of size of the switches. A fine tuning as well as coarse tuning is possible because it is capable of controlling the number of inductor's windings used for each port freely.
In addition, in accordance with the present invention, it is possible to acquire characteristics of broadband tuning for a matching circuit of low noise amplifiers and VCO (Voltage Controlled Oscillator), and high power for PA (power amplifier).
And, in case of applying the present invention to an optical transceiver, it is possible to change a single input to a dual input by locating it between a photo diode of a receiver and a transimpedance amplifier and it can also isolate the receiver and the transimpedance amplifier. Meanwhile, in this case, it is capable of decreasing a capacitance factor by tuning the inductance.
Moreover, in accordance with the present invention, due to the variety of the inductance value, which is changed by the number of metal layers and inductors used for stacking, it is possible to determine a structure of a variable inductor and the number of windings, thereby applying it to a circuit according to the inductance value desired for the circuit.
In addition, in accordance with the present invention, as a result of adding one more variable to a circuit tuned by a conventional variable capacitor, a range of tuning increases greatly and, therefore, it is possible to design and produce a circuit, which has characteristics of a broadband and a wide tuning range.
The present application contains subject matter related to Korean patent application No. 2004-0107114, filed in the Korean Intellectual Property Office on Dec. 16, 2004, the entire contents of which is incorporated herein by reference.
While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.
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There is provided a transformer for varying an inductance value, which adjusts a tuning range of the inductance without decrease of the inductor's capability by selectively connecting switches to inductors and controls an amount of magnetic flux. And the transformer consists of multiple inductors formed on a semiconductor substrate, which including N number of metal lines, N number of ports made by twisting the metal lines in the form of a symmetric circuit, wherein a certain number of ports among the N number of ports, which are connected to switch elements.
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FIELD OF THE INVENTION
This invention relates to a transmission for self-propelled walking mowers.
BACKGROUND OF THE INVENTION
As is disclosed in, for example, JP, A No. 61-56015, JP, A(U) No. 59-68047, JP, A(U) No. 60-79919 and JP, A(U) No. 60-168325, a transmission for propelling a walking mower according to the prior art is, in general, fashioned such that it transmits power of an engine to left and right drive wheels without a speed-change control and only with a speed-reduction control.
A prior art transmission including a speed-change mechanism is known from JP, A(U) No. 61-135057. Although structure of the speed-change mechanism cannot be understood exactly from the specification and drawings of this laid-open application, it is believed that the change mechanism provides only few variable speeds, such as two variable speeds, of a walking mower.
The reason why a transmission for walking mowers has been fashioned to have no speed-change mechanism or to have a speed-change mechanism providing only few variable speeds, as described above, is that a compactness of the transmission is to be secured so as to eliminate a limitation against the arrangement of a mowing cutter and so as not to sacrifice a compactness of the whole of a mower. It is believed, however, very convenient if speed of a walking mower could be selected from a plurality of variable speeds in accordance with height and/or density of turfs, operator's liking and so on. Further, it is wished to travel a walking mower with a relatively high speed when the mower is not used for mowing and is merely travelled.
OBJECT
Accordingly, a primary object of the present invention is to provide a novel transmission for self-propelled walking mower in which a key-shift transmission or speed-change mechanism, known from, for example, U.S. Pat. Nos. 3,812,735 and 4,103,566 and providing a plurality of variable speeds with a compact structure, is employed in a compact fashion.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become readily apparent as the specification is considered in conjunction with the accompanying drawings, in which:
FIG. 1 is a sectional plane view of a transmission casing employed in a first embodiment of the transmission according to the present invention;
FIG. 2 is a schematic perspective view, partially cut away, of a self-propelled walking mower in which the first embodiment is employed;
FIG. 3 is a vertical sectional view, showing a rear wheel assembly in the walking mower shown in FIG. 2;
FIG. 4 is a sectional view taken generally along line IV--IV of FIG. 1;
FIG. 5 is a sectional view taken generally along line V--V of FIG. 1;
FIG. 6 is a perspective view, showing one end portion of a hollow change-shaft shown in FIG. 1;
FIG. 7 is a perspective view, showing a control fork mechanism employed in first embodiment in a disassembled state;
FIG. 8 is a plane view, partially omitted, of the transmission casing shown in FIG. 1;
FIG. 9 is a sectional plane view similar to FIG. 1, but showing an essential part of a second embodiment of the transmission according to present invention;
FIG. 10 is a sectional view taken generally along line X--X of FIG. 9;
FIG. 11 is an enlarged sectional view of a part of the second embodiment;
FIG. 12 is an enlarged sectional plane view of a part of the second embodiment; and
FIG. 13 is an enlarged sectional plane view of the part shown in FIG. 12, showing a state different from that shown in FIG. 12.
SUMMARY OF THE INVENTION
The present invention relates to a transmission for self-propelled walking mower which comprises, as shown in FIG. 2, an engine 1, a main clutch 2, and a transmission casing 3.
As shown respectively in FIG. 1 and in FIG. 9, the transmission according to the present invention further comprises a drive shaft 4 and speed-change shaft 5 which are journalled respectively in the transmission casing 3 and extend parallel with each other. The drive shaft 4 is connected drivenly to the engine 1 through the main clutch 2. The speed-change shaft 5 is formed particularly of a hollow shaft. One end of such hollow speed-change shaft 5 is spaced axially from an inner wall surface of the transmission casing 3 by an interval D, as shown respectively in FIG. 1 and in FIG. 9.
As also shown respectively in FIG. 1 and in FIG. 9, an axle 6 extends through the hollow speed-change shaft 5 and through the transmission casing 3. Such axle 6 is drivingly connected, as shown in FIGS. 2 and 3, to left and right drive wheels 7.
Within the transmission casing 3 is disposed a key-shift transmission mechanism 8, as shown respectively in FIG. 1 and in FIG. 9. Such transmission mechanism 8 has a plurality of drive gears 9I, 9II, 9III, 9IV and 9V which are fixedly mounted on the drive shaft 4, a plurality of speed-change gears 10I, 10II, 10III, 10IV and 10V which are rotatably mounted on the speed-change shaft 5 and are meshed respectively with the drive gears 9I-9V, and a shift key 12 which is disposed slidably within an elongated axial groove 11 in the outer surface of the speed-change shaft 5 and includes a gear-engaging lug 12a for coupling the speed-change gears 10I-10V one at a time to the change shaft 5.
As shown respectively in FIG. 1 and in FIG. 9, an auxiliary clutch 13 is disposed within the interval D referred to before. This clutch 13 is fashioned such that it is operable to connect and disconnect between the speed-change shaft 5 and axle 6. A clutch lever 14 shown in FIG. 2 is provided which is connected to both of the main and auxiliary clutches 2 and 13 and is operable to engage and disengage these clutches together.
During a mowing operation using a walking mower including the transmission according to the present invention, speed of the walking mower can be selected from a plurality of variable speeds by a shifting operation of the key-shift transmission mechanism 8. Such selection of the speed is made in accordance with height and/or density of turfs, operator's liking and so on. When the walking mower is merely travelled, a relatively high speed of the mower may be attained by shifting the key-shift transmission mechanism 8 to its highest speed ratio.
Before a shifting operation of the key-shift transmission mechanism 8, the main clutch 2 is disengaged by the clutch lever 14. Because the auxiliary clutch 13 is disengaged at the same time, the speed-change shaft 5 is made freely rotatable on the axle so that the shifting operation can be carried out lightly.
When an operator intends to retreat the walking mower by pulling same in such a case where unmowed turfs are found behind the mower, the main clutch 2 is disengaged for disconnecting the axle 6 from engine 1. In this case, too, the auxiliary clutch 13 becomes disengaged so that the axle 6 is disconnected from the speed-change shaft 5. Consequently, gearing which is incorporated between the main clutch 2 and speed-change shaft 5 and has a speed-reducing function does not provide a resistance against a pulling operation for treating the mower so that the operator can retreat the mower with ease.
In the transmission according to the present invention, the hollow speed-change shaft 5 is employed, and is arranged coaxially with the axle 6 by passing the axle through the change shaft. Such speed-change shaft 5 permits to provide the key-shift transmission mechanism 8 having a plurality of change ratios without sacrificing a compactness of the transmission or the casing 3 thereof. Further, the auxiliary clutch 13, by which both of the shifting operation and mower-retreating operation are made easy as described above, is provided in a compact fashion by utlizing the coaxial arrangement of speed-change shaft 5 and axle 6 and by utilizing the interval (D) between one end of the change shaft and an inner wall surface of the transmission casing 3.
DESCRIPTION OF PREFERRED EMBODIMENTS
In FIGS. 1 to 8, a first preferred embodiment is shown.
In FIG. 2 which depicts schematically the whole of a walking mower in which the embodiment is employed, numeral 16 designates a machine frame or deck which supports left and right front wheels 17 freely rotatably. To a rear end portion of the deck 16 is attached a steering handle 18 which extends upwardly and backwardly from the deck. The engine 1 referred to before is mounted on the deck 16. Drive wheels also referred to before are provided by left and right rear wheels 7. A mowing cutter 19 driven by engine 1 is arranged at a lower side of the deck 16.
As also shown in FIG. 2, the transmission casing 3 referred to before is fixedly secured to a rear end portion of the deck 16 and has an input shaft 20 extending upwardly from the casing. Engine output shaft 1a has thereon a pulley 21. A belt 23 is entrained over this pulley 21 and another pulley 22 fixedly mounted on the input shaft 20. The main clutch 2 referred to before is provided by a belt-tightening clutch comprising a tightening roller 2a which tightens the belt 23 when it is pressed against the belt. This roller 2a is supported by a rotatable arm 2b which is biased by a spring 2c to rotate towards a direction to move the roller 2a away from the belt 23 and which is connected through a control cable 24 to the clutch lever 14 referred to before. The clutch lever 14 shown is fashioned such that when it is grasped or operated the main clutch 2 becomes engaged so as to tighten the belt 23.
As shown in FIGS. 2 and 3, the wheel disk 7a of each rear wheel 7 is formed with an internal gear 25 with which a gear 26 attached to each end of the axle 6 is meshed so as to transmit rotation of the wheel axle to each rear wheel 7 with a reduced speed of rotation of about a quarter. To each side wall of the deck 16 is attached an axle-supporting plate 27 having a pin 28 secured thereto by which each rear wheel 7 is rotatably supported at a central boss 7b of the wheel disk 7a. Each end portion of the axle 6 is supported by the plate 27 through a bushing 29.
As shown in FIGS. 4 and 5, the transmission casing 3 is composed of mutually jointed upper and lower casing halves. As shown in FIGS. 1 and 4, a large bevel gear 31 is fixedly mounted on one end portion of the drive shaft 4. This bevel gear 31 is meshed with a smaller bevel gear 32 which is formed integrally with an inner end portion of the input shaft 20. Five drive gears 9I-9V are fixedly mounted on the drive shaft 4, and five speed-change gears 10I-10V are rotatably mounted on the speed-change shaft 5. These gears 9I-9V and 10I-10V are meshed respectively so as to provide first to fifth speed-change gear trains between the shafts 4 and 5.
As shown in FIG. 1, two of the elongated axial grooves 11 referred to before are formed in the outer surface of speed-change shaft 5 and two of the shift keys 12 referred to before are provided. As is usual in a key-shift transmission mechanism, each of the speed-change gears 10I-10V on the shaft 5 has at the inner circumference thereof recesses 33 into which key-engaging lugs 12a of the shift keys 12 may project. The hollow speed-change shaft 5 shown has one end, spaced from a side wall of the transmission casing 3 by the interval D referred to before, and the other end which takes a middle position between two side walls of the casing. On the axle 6 is further mounted a hollow support shaft 60 of a synthetic resin having at its outer surface two elongated axial grooves 60a which are aligned axially with the grooves 11 in the change shaft 5. On this support shaft 60 is slidably mounted a shifter sleeve 34 to which the shift keys 12 are attached so that these keys are moved axially within the grooves 11 and 60a by a sliding movement of the shifter sleeve. For biasing each shift key 12 to move towards a direction such that gear-engaging lug 12a thereof is projected radially outwardly of the speed-change shaft 5, a leaf spring 35 is disposed within the elongated grooves 11 and 60a and is attached to an inward projection 12b on a base end portion of the key 12. Such leaf spring 35 is shaped so that it is in a slidable engagement at a mid portion thereof with the bottom surfaces of grooves 11 and 60a and resiliently engages at its free end portion to the shift key 12. Outer diameter of the change shaft 5 is made somewhat larger than that of the support shaft 60 and an annular stopper surface 61 for limiting the displacement of shifter sleeve 34 is provided by a portion of an end face of the change shaft 5 which portion extends radially outwardly over the support shaft 60.
For displacing the shifter sleeve 34 axially of the support shaft 60, a shifter fork 36 shown in FIG. 4 is provided which is supported by the transmission casing 3 rotatably about a vertical axis and is engaged to the shifter sleeve. To this shifter fork 36 is attached a shifter arm 37 which is disposed above the transmission casing 3. As shown in FIG. 2, the shifter arm 37 is connected through a control cable 39 to a change lever 38 provided to the steering handle 18. The shifter sleeve 34 is operated to slide by the control mechanism detailed above so as to displace the shift keys 12 selectively to one of a neutral position, where the gear-engaging lugs 12a do not engage any of the change gears 10I-10V as shown in FIG. 1, and five operative positions where the lugs 12a project into the recesses 33 of one of the change gears 10I-10V so as to couple the gear to the change shaft 5.
As shown in FIGS. 1 and 5, the auxiliary clutch 13 referred to before has a clutch sleeve 41 which is mounted on the axle 6 slidably within the interval D referred to before. This clutch sleeve 41 includes an annular groove 41a, having an inner diameter larger than the outer diameter of axle 6, and a pair of opposed recesses 41b formed in the peripheral surface of the annular groove 41b. To the axle 6 is fixedly secured a pin 42 which projects at both ends thereof into the recesses 41a referred to above so as to connect the clutch sleeve 41 co-rotatably to the axle 6. The pin 42 also provides a stopper means which limits a sliding movement of the clutch sleeve 41 towards a direction away from the speed-change shaft 5. As shown in FIG. 6, the hollow change shaft 5 is formed at one end portion thereof with a suitable number of clutch teeth 43 which are disposed intermittently along a circular direction. Corresponding clutch teeth 44 shown in FIG. 1 are provided to the clutch sleeve 41. The auxiliary clutch 13 is fashioned such that it is engaged when the clutch teeth 44 of clutch sleeve 41 are meshed with the clutch teeth 43 of change shaft 5.
For displacing the clutch sleeve 41 so as to engage and disengage the clutch 13, a control fork 46 shown in FIG. 5 is provided which is supported by the transmission casing 3 rotatably about a vertical axis and is engaged to the clutch sleeve 41. As shown in FIG. 7, the control fork 46 is made of a plate material by punching and is adapted to be supported by the transmission casing rotatably through a pair of cylindrical members 47 each having a bore 47a into which a portion of the fork is fitted. The shifer fork 36 shown in FIG. 4 is fashioned similarly.
An upper end portion of the control fork 46 which is projected upwardly from the transmission casing 3 carries a clutch arm 48 which is prevented from getting-out by a pin 49, as shown in FIGS. 5 and 8. As shown in FIGS. 2 and 8, this clutch arm 48 is connected to the clutch lever 14, referred to before, through a spring 50 and control cable 51. As shown in FIG. 8, the clutch arm is biased by another spring 52 to move towards a direction away from the spring 50 and cable 51. The auxiliary clutch 13 shown in fashioned such that the clutch sleeve 41 shown in FIGS. 1 and 5 is located at a clutch-disengaging position under the biasing of such another spring 52 when the clutch lever 14 is not grasped or operated.
Consequently, the auxiliary clutch 13 becomes engaged when the control cable 51 is pulled by an operation of the clutch lever 14 so as to displace the clutch sleeve 41 to the position shown in FIG. 1. The main and auxiliary clutches 2 and 13 are fashioned to be engaged and disengaged in a manner which will be detailed hereinafter.
In FIG. 8, characters P 1 and P 2 represent respectively clutch-disengaging and -engaging positions of the clutch arm 48 for the auxiliary clutch 13. On the upper surface of transmission casing 3 is provided a stopper projection 53 which limits a rotation of the clutch arm 48 when it has been rotated to the clutch-engaging position P 2 by an operation of the clutch lever 14. It is fashioned that, when the clutch arm 48 has reached the clutch-engaging position P 2 shown in FIG. 8, the rotatable arm 2b of the main clutch 2 shown in FIG. 2, which arm is also rotated by the operation of clutch lever 14, still takes a position where tightening of the belt 23 by the tightening roller 2a is not caused. A further operation of the clutch lever 14 will cause a displacement or rotation of the rotatable arm 2b to its belt-tightening position while causing a tension of the spring 50 between the clutch arm 48 and control cable 51 shown in FIG. 8. Conversely, when the clutch lever 14 is released for a clutch-disengaging purpose, spring 50 becomes shortened so as to pull the cable 51 towards such spring 50. The clutch lever 14 will go down spontaneously to loosen the cable 24, and the rotatable arm 2b will be rotated by the force of spring 2c to disengage the main clutch 2. Then, the clutch arm 48 will be rotated by the force of spring 52 to the clutch-disengaging position P 1 shown in FIG. 8.
The walking mower shown in FIG. 2 is driven to travel for a mowing purpose with the clutch lever 14 being grasped by an operator behind the mower. Before a shifting operation of the key-shift transmission mechanism 8, the main and auxiliary clutches 2 and 13 are disengaged by releasing the clutch lever 14. These clutches are also disengaged when the operator intends to retreat the mower by pulling the steering handle 18 for unmowed turfs found behind him or the like.
When the clutch lever 14 is grasped again for engaging the main and auxiliary clutches, the main clutch 2 which may tighten the belt 23 gradually without causing a shock becomes engaged after the auxiliary clutch 13 has been engaged. Consequently, a sudden start of the rotation of rear wheels 7 which might cause a floating state of the front wheels 17 is well avoided and the mower will start in a smooth manner owing to a shock-free engaging of the main clutch 2.
In FIGS. 9 to 13, there is shown a second preferred embodiment of the present invention in which a ball clutch is employed as a clutch 13 for connecting and disconnecting between the speed-change shaft 5 and axle 6.
In this second embodiment, the hollow speed-change shaft 5 has a diameter-reduced end portion 5a which includes therein a pair of radial thorough bores 71. In these bores are received a pair of balls 72 which are movable radially of the change shaft 5. Within the end portion 5a of change shaft 5, the outer surface of axle 6 is formed with a pair of recesses 73 into which inner halves of the balls 72 may project. The interval D referred to before is also provided, and a clutch sleeve 74 is disposed within such interval. The sleeve 74 is mounted slidably and rotatably on the axle 6 and has at its inner circumference a first sloped cam surface 74a for pushing balls 72 radially inwardly of the axle 6 and a second sloped cam surface 74b for keeping balls 72 at their pushed-in positions or clutch-engaging positions.
When the clutch sleeve 74 is located at a position shown with respect to an upper half of such sleeve in FIGS. 9 and 10 and shown in FIGS. 11 and 12, each ball 72 is located at its clutch-engaging position where a side end surface of each bore 71 in the change shaft 5 pushes the ball against a side end surface of each recess 73 in the axle 6 so as to transmit a rotation of the change shaft 5 to axle 6. When the clutch sleeve 74 is displaced away from the change shaft 5 to another position shown with respect to a lower half of such sleeve in FIG. 9 and shown in FIG. 13, a reaction force, which is applied to each ball 72 by the axle 6 and has a component directed radially outwardly of the axle, will get the ball out of recess 73 so that the auxiliary clutch 13 becomes disengaged.
A snap ring 75 is disposed on the axle 6 for limiting a sliding movement of the clutch sleeve 74 towards the change shaft 5 at the clutch-engaging position of sleeve 74, as shown in FIG. 12. The other parts of the second embodiment are fashioned similarly to the corresponding parts of the first embodiment and are designated by like numerals.
Each of the auxiliary clutches 13 employed in the first and second embodiments is kept in its engaged condition by grasping a clutch lever continuously. During such grasping of the clutch lever, a biasing force of spring means, such as spring 52 shown in FIG. 8, for disengaging the clutch is applied continuously to operator's hands. Consequently, it is preferred to lower a force required for disengaging the clutch from an engaged condition thereof so that the biasing force of spring means set forth above may be reduced. In this respect, the auxiliary clutch employed in the second embodiment is superior to the one employed in the first embodiment by the reason which will be detailed hereinafter.
The auxiliary clutch 13 employed in the first embodiment requires, for detaching the meshing clutch teeth 43 and 44 shown in FIG. 1, to displace the clutch sleeve 41 against a frictional force acting between these teeth 43 and 44 and against another frictional force acting between the clutch sleeve 41 and a pin 42 shown or another means, such as a sliding key or spline, for connecting the clutch sleeve non-rotatally but slidably to the axle 6. The last-mentioned frictional force is considerably large at a condition where the key-shift transmission mechanism 8 is shifted to a lower speed ratio and rotation speed of the axle 6 is thus low. It is thus seen that the biasing force of the spring 52 shown in FIG. 8 must be large enough to disengage the clutch even at the lowest speed ratio of the transmission mechanism 8.
Contrarily to this, the clutch sleeve 74 employed in the second embodiment is mounted freely rotatably on the axle 6. Consequently, such clutch sleeve 74 may be displaced from the clutch-engaging position shown in FIG. 12 only against a frictional force acting between the ball 72 and clutch sleeve 74. In addition to this, the sleeve 74 includes a slightly sloped cam surface 74b by which a reaction force of the rotating axle 6 is applied through balls 72 to the clutch sleeve 74 effectively at an initial stage of clutch-disengaging operation. It is thus seen that spring means to be provided in the second embodiment for disengaging the auxiliary clutch 13 may have a relatively small biasing force.
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Within a transmission casing (3) having therein a drive shaft (4), driven by an engine (1) through a main clutch (2), and a hollow speed-change shaft (5), a key-shift transmission mechanism (8) is disposed which comprises a plurality of meshing gears (9I-9V, 10I-10V) mounted respectively on the drive and change shafts. An axle (6) drivingly connected to left and right drive wheels (7) extends through the hollow change shaft. One end of the change shaft is spaced from an inner wall surface of the transmission casing for disposing therebetween an auxiliary clutch (13) which is operable between the change shaft and axle. Both of the main and auxiliary clutches are operated together.
The transmission mechanism is provided for a plurality of variable speeds of a mower in a compact fashion owing to a co-axial arrangement of the hollow change shaft and the axle passing therethrough. The auxiliary clutch which is provided also in a compact fashion permits to shift the transmission mechanism lightly and to pull the mower for retreating same with ease.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of agricultural equipment, and particularly to center pivots.
[0003] 2. Description of the Related Art
[0004] Center pivots are commonly used to irrigate large areas of and that are typically a quarter mile on each side. The center pivot includes a base that is attached to the ground and number of segments attached together that are supported on wheels for allowing them to rotate around the base.
[0005] Due to landscape and other considerations, there are situations that require farmers to install center pivots in locations where it is possible that the center pivots will collide. Originally, farmers were required to watch their pivots to prevent collisions. With the advent of global position satellites (GPS), farmers were allowed to use computers to detect collisions. The method commonly employed with GPS is the “box method” where a region that center pivots may collide is described with a bounding box. If both pivot enters the box at the same time then action is taken to prevent the collision. The simplistic box method does not take into account the velocity or directions of the pivots and many times will report a collision and shutdown equipment when unnecessary. Current center pivot collision detection systems do not take velocity into account because center pivots move at a slow rate that cannot be detected with current GPS hardware. When a center pivot is shutdown unnecessarily a farmer incurs expenses in restarting the center pivot and for a loss in the yield of the crop. Therefore, there exists a need for a new and improved method and system for detecting collisions between center pivots.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] This invention is described in a preferred embodiment in the following description with reference to the drawings, in which like numbers represent the same or similar elements, as follows:
[0007] FIG. 1 is a schematic of center pivot.
[0008] FIG. 2 illustrates the prior art box method for detecting center pivot collision.
[0009] FIG. 3 depicts an example of center pivots in accordance with the present invention.
[0010] FIG. 4 illustrates a high level flow chart for a preferred embodiment of detecting center pivot collision of the present invention.
[0011] FIG. 5 shows a flow chart for a preferred embodiment of obtaining a center pivot velocity for detecting center pivot collision of the present invention.
[0012] In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] In the following detailed description of exemplary embodiments of the invention, specific exemplary embodiments in which the invention may be practiced 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 logical, architectural, programmatic, mechanical, electrical and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
[0014] When referring to the location of a center pivot, the location is the position of the end tower of the center pivot or the farthest most extension of the pivot pipe away from the pivot base.
[0015] The location of a center pivot is obtained with a position sensor. While referring to GPS coordinates and devices in conjunction with the figures, those familiar with the art will recognize that other types of position sensors may be utilized. For instance, an encoder type position sensor may be utilized to calculate the location of a center pivot.
[0016] As described herein, a database generally refers to the storage of information for later retrieval. A database is not confined to the storage of a single device and includes information that is stored on multiple devices that are in communication with one another.
[0017] A processor refers to a single computation device or multiple computational devices working together.
[0018] With reference now to the figures, and in particular with reference to FIG. 1 , there is shown an overhead schematic of a center pivot. Center Pivot Base 4 is located near the center of Growing Field 2 . The common size of a growing field is one quarter mile by one quarter mile; however, the size of a growing field may vary widely. Center Pivot Base 4 is attached to the ground and includes a rotation mechanism (not shown) that connects to Pivot Pipe 6 .
[0019] Pivot Pipe 6 is supported by Intermediate Tower 8 , 10 , 12 , and 14 . Intermediate Towers 8 , 10 , 12 , and 14 include wheels for allowing tangential movement with respect to Center Pivot Base 4 . Paths 18 , 20 , 22 , and 24 show the travel path of intermediate Towers 8 , 10 , 12 , and 14 , respectively, as they travel around Growing Field 2 . Intermediate Towers 8 , 10 , 12 , and 14 may travel in either clockwise or counter-clockwise direction. Those familiar with the art common refer to clockwise direction as travelling forward and counter-clockwise as travelling in reverse.
[0020] Pivot Pipe 6 terminates at End Tower 16 . End Tower 16 is similar to Intermediate Towers 8 , 10 , 12 , and 14 . In some instances, End Tower 16 may extend Pivot Pipe 6 to further without any additional ground support and include an end gun (not shown) for watering the corners of Growing Field 2 .
[0021] With referenced now to FIG. 2 , a schematic diagram of the “box method” for detecting center pivot collisions is illustrated. Pivot Base 202 is attached to Pivot Pipe 204 and follows Pivot Path 206 . Pivot Base 208 is attached to Pivot Pipe 210 and follows Pivot Path 212 . It is apparent from the figure that Pivot Pipe 204 and Pivot Pipe 210 may collide in Pivot Collision Box 214 . As Pivot Pipe 204 and 210 travel along their respective paths, a GPS coordinate is monitored. If the GPS coordinate falls within Pivot Collision Box 214 a collision is alerted and the farmer is notified and/or equipment is shut down.
[0022] Since center pivots move at a rate below one mile per hour, the velocity of center pivots has previously been unused to assist in determining when pivots would collide. Instead, prior art solutions rely on a the primitive box method that will signal a collision if two center pivots pipes, such as Pivot Pipe 204 and Pivot Pipe 210 , enter into a defined box, Pivot Collision Box 214 .
[0023] The prior art box method does not take into account the direction or velocity of either pivot which results in center pivots being shut off when no collision would have happened. Without having a means to represent the velocity of the center pivot, the future location of the center pivot may not be predicted. The present invention addresses this shortcoming.
[0024] With referenced now to FIG. 3 , a schematic diagram of a preferred embodiment of the present invention for detecting center pivot collisions is depicted. For Center Pivot A comprising Pivot Base 202 and Pivot Pipe 204 , a set of recent GPS coordinate and time information is recorded at Location 332 , 334 , and 336 . Similarly, for Center Pivot B comprising Pivot Base 208 and Pivot Pipe 210 , a set of recent GPS coordinate and time information is recorded at Location 320 , 322 , and 324 .
[0025] Based on the recent GPS information at Location 332 , 334 , and 336 , the angular velocity of Pivot Pipe 204 is calculated. Future Location 338 , 340 , and 342 represent positions Pivot Pipe 204 will be at future times. Likewise, based on the recent GPS information at Location 320 , 322 , and 324 , the angular velocity of Pivot Pipe 208 is calculated. Future Location 326 , 328 , and 330 represent positions Pivot Pipe 208 will be at future times.
[0026] The future spatial locations of Center Pivot A and Center Pivot B are compared to determine if the pivots will collide as is further described in conjunction with FIG. 4 and FIG. 5 . An added benefit of the present invention is that the time and location of a collision is calculated to allow equipment to operate as long as possible before a shutdown is required.
[0027] Those familiar with the art will recognize that while a sample of three previous locations is shown in FIG. 3 , any sample size with one or more locations would be sufficient to practice the present invention. Similarly, while three future locations are calculated for the pivot, any set of future locations that have one or more locations is within the scope and spirit of the present invention.
[0028] With referenced now to FIG. 4 , a flow chart of a preferred embodiment of the present invention for detecting center pivot, collisions is illustrated. By way of example, the flow chart of FIG. 4 shows the process of detecting a collision between Center Pivot A and Center Pivot B. The process begins at Step 402 where spatial information, such as the center pivot base location, center pivot length, end tower location, and velocity are obtained from a database for Center Pivot A and Center Pivot B. In a preferred embodiment, the velocity of the center pivots is calculated in degrees per hour. The process at Step 402 is explained in further detail in conjunction with FIG. 5 .
[0029] Following Step 402 , the process moves to Step 404 . At Step 404 one or more future positions of Pivot A and Pivot B are calculated. In a preferred embodiment, the future locations are based on the velocity calculated at Step 402 . In yet, another preferred embodiment, the velocity calculated in Step 402 is adjusted such that it is within a minimum and maximum velocity for the pivot.
[0030] At decision Step 406 a determination is made if Pivot A and Pivot B will collide. The decision is based on comparing the locations of Pivot A and Pivot B in the future. If Pivot A and Pivot B will occupy the same space at any of the future locations, a collision is indicated and the process advances to Step 408 , if no collision is indicated then the process ends.
[0031] In a preferred embodiment, the determination at Step 406 factors in a safety margin, expressed in a linear measurement such as feet. If Pivot A and Pivot B will be at any calculated future time less than the safety margin apart, a collision is indicated. Additionally, the distance between Pivot A and Pivot B is calculated as the closest distance between the pivot pipes. In yet another preferred embodiment, the distance between the center pivots is calculated as the distance between the center pivot end towers.
[0032] Following a determination of a collision, the process advances to Step 408 . At Step 408 , the farmer or equipment operator is notified of the collision and the center pivots are stopped. In a preferred embodiment, the farmer or equipment operator is notified in advance of the collision and given time to make corrections to the center pivots if the collision will not take place in the immediate future.
[0033] With referenced now to FIG. 5 , a flow chart for a preferred embodiment of obtaining a center pivot velocity for detecting center pivot collision of the present invention is shown. Those familiar with the art will recognize that the steps show in FIG. 5 may be executed in different orders or in parallel without departing from the spirit and scope of the present invention.
[0034] In a preferred embodiment, the process of calculating the velocities for two center pivots, Center Pivot A and Center Pivot B, being checked for collision starts at Step 502 . At Step 502 the center locations for Center Pivot A and Center Pivot B are retrieved from a database. The center locations are expressed in longitude and latitude coordinates.
[0035] The process advances to Step 504 where the lengths of Center Pivot A and Center Pivot B are retrieved from a database. The length of the pivots is expressed in feet, but other embodiments may use other units of measure.
[0036] After Step 504 , the process moves to Step 506 where recent locations are retrieved for Center Pivot A and Center Pivot B. The recent locations include a coordinate and a time the center pivot was at the coordinate. In a preferred embodiment, the number of recent locations is two or more. Further, in a preferred embodiment, the recent locations include the current location of the pivot.
[0037] The process then advances to Step 508 . At Step 508 the velocities of Center Pivot A and Center Pivot B are calculated based on the recent locations, in a preferred embodiment, the average angular velocity between the recent locations is calculated.
[0038] For an embodiment that does not utilize the current location of a pivot, the current location is calculated based on the last reported location, time since the last reported location, and the average angular velocity.
[0039] While the invention has been particularly shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. Any variations, modifications, additions, and improvements to the embodiments described are possible and may fall within the scope of the invention as detailed within the following claims.
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A system and method is described that allow for detecting center pivot collision and that provide more accurate and reliable collision indications. The system and method described are suitable for low-cost consumer grade GPS devices and other position sensors.
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BACKGROUND OF THE INVENTION
The present invention relates to a device for displaying a video signal, and more particularly, to a video display controlling device which enables an arbitrarily transformed image to be displayed on a monitor based upon a user's command.
This application regarding a video display controlling device is based upon Korean Patent Application No. 95-32198, filed Sep. 27, 1995, which is incorporated by reference herein for all purposes.
When a video signal is input to a video displaying device it is displayed on a monitor. In such a situation, a function of transforming the image upon a user's command and then displaying the transformed image is desirable.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a video display controlling device which can perform an image transformation, such as image compression or expansion, by manipulating a video signal to be displayed on a screen.
To accomplish the above object, there is provided a video display controlling device comprising a display means, a storing means, a reference pixel setting means, an image mode setting means, and an address generating means. The display means displays an image constituted by (N×M) pixel data on a screen. The storing means stores (N+a)×(M+b)! pixel data associated with an image, where addresses for reading the pixel data are composed of vertical addresses from 0 to (N+a-1) and horizontal addresses from 0 to (M+b-1), and the reference letters a and b are positive integers. The reference pixel setting means sets vertical and horizontal addresses of a reference pixel data among pixel data stored in the storing means. The image mode setting means sets an image mode for transforming an original image according to a predetermined pattern and displaying the transformed image on the screen of the displaying means. The address generating means generates addresses for selecting a predetermined pixel data among the (N+a)×(M+b)! pixel data, in accordance with the reference pixel data and the image mode. The pixel data read from the storing means at the vertical and horizontal addresses, which are generated by the address generating means, is displayed on the screen of the displaying means.
BRIEF DESCRIPTION OF THE DRAWINGS
The above object and advantage of the present invention will become more apparent as a preferred embodiment of thereof is described in detail with reference to the attached drawings in which:
FIG. 1 is a block diagram of a video display controlling device according to the present invention;
FIG. 2 shows an (N×M) pixel of a monitor and a (N+a)×(M+b)! pixel stored in a memory, respectively;
FIG. 3 shows an image which can be displayed using the (N+a)×(M+b)! pixel stored in the pixel memory;
FIGS. 4A & 5A each show address settings in accordance with a normal image display mode;
FIGS. 4B & 5B each show an image to be displayed in accordance with the normal mode address settings shown in FIGS. 4A & 5A, respectively;
FIGS. 6A and 6B show, respectively, an address setting and an image to be displayed according to the address setting, according to a vertical compression mode;
FIGS. 7A and 7B show, respectively, an address setting and an image to be displayed according to the address setting, according to a horizontal compression mode;
FIGS. 8A & 9A each show address settings according to a full compression mode;
FIGS. 8B & 9B each show an image to be displayed in accordance with the full compression mode address settings of FIGS. 8A & 9A, respectively;
FIGS. 10A & 11A each show an address setting according to an expansion mode;
FIGS. 10B & 11B each show an image to be displayed in accordance with the expansion mode address settings of FIGS. 10A & 11A, respectively; and
FIG. 12 shows a progression of address settings according to a "moving" mode.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the video display controlling device according to the present invention includes a monitor 18 which is a display device capable of displaying a video image composed of (N×M) pixel data. Pixel memory 17 stores (N+a)×(M+b)! pixel data associated with an image, wherein an address for reading the pixel data is comprised of vertical addresses from 0 to (N+a-1) and horizontal addresses from 0 to (M+b-1) (here, the reference letters a and b are positive integers). The initial value setting unit 11 sets vertical and horizontal addresses of reference pixel data among pixel data stored in the pixel memory 17. An image mode setting unit 16 sets an image mode, such as a mode for compressing or expanding an original image and then displaying it. Vertical address generating unit 12 sequentially generates vertical addresses, for accessing the pixel memory 17, starting from the vertical address set by the initial value setting unit 11. Likewise, horizontal address generating unit 13 sequentially generates horizontal addresses, for accessing the pixel memory 17, starting from the horizontal address set by the initial value setting unit 11. An address selection controlling unit 15 generates a control signal for controlling the selection of a predetermined pixel data among the (N+a)×(M+b)! pixel data in the pixel memory 17, depending on the address of the reference pixel data and the image mode. The address selecting unit 14 selects the vertical addresses generated by the vertical address generating unit 12 and the horizontal addresses generated by the horizontal address generating unit 13 (depending on the control signal form the address selection controlling unit 15) in sequence or in a predetermined interval unit, and then generates addresses for accessing the pixel memory 17.
The present invention is capable of operation according to the following image modes. In a normal mode, an original image is displayed without transformation. In a vertical compression mode the original image is compressed in a vertical direction before displaying it. In contrast, the horizontal compression mode compresses the original image in a horizontal direction before displaying it. The full compression mode compresses the original image in horizontal and vertical directions and displaying it, whereas the expansion mode expands a portion of the original image and displaying it. A moving mode is provided for displaying the original image with respect to an image stored in the pixel memory 17 as a plurality of images on the screen of the monitor 18.
FIG. 2 shows an (N×M) pixel matrix to be shown on the monitor 18, and a (N+a)×(M+b)! pixel matrix stored in the pixel memory 17. Here, the variable "N" represents the amount of pixels capable of being vertically displayed on the monitor 18, and thus the term (N+a) represents an amount of pixels which exceeds the capacity of the monitor 18. Likewise, the term (M+b) represents an amount of pixels which exceeds the amount "M" capable of being horizontally displayed on the monitor 18. The drawings show a display of pixel data having addresses from (0, 0) to (N-1, M-1) in the pixel memory 17.
FIG. 3 shows a full image representing image data which can be displayed by using the (N+a)×(M+b)! pixel data stored in the pixel memory 17. The pixel memory 17 stores more pixel data than will fit on the screen of the monitor 18.
Hereinbelow, address settings according to settings of an image mode and a reference pixel data, and an image to be displayed according to the address settings will be described referring to the drawings.
FIG. 4A shows an address setting for sequentially selecting the (N×M) pixel from the pixel memory 17 starting from address (0, 0). FIG. 4B shows the image displayed on the monitor 18 according to the address set shown in FIG. 4A. In this case, the image mode setting unit 16 sets the image mode as a normal mode. Accordingly, the initial value setting unit 11 sets the vertical and horizontal addresses of the reference pixel data to "0". The address selecting unit 14 sequentially generates vertical addresses from "0" to (N-1) and horizontal addresses from "0" to (M-1). That is, the pixel data of the pixel memory 17, having addresses from (0, 0) to (N-1, M-1), is selected and displayed on the screen of the monitor 18. In FIG. 4B, the shaded portion denotes pixel data stored in the pixel memory 17 which is not displayed on the monitor 18. Hereinbelow, this explanation is applied in a similar manner to the following drawings.
FIG. 5A shows an address setting for sequentially selecting the (N×M) pixel data from the pixel memory 17, starting from an arbitrary position, and FIG. 5B shows an image displayed on the monitor 18 according to the address set shown in FIG. 5A. In this case, the image mode is set as a normal mode as in FIGS. 4A and 4B, but the vertical and horizontal addresses of the reference pixel data are set as K1 and K2 (here, K1 and K2 are integers larger than zero), respectively. Here, the address selecting unit 14 sequentially generates vertical addresses from K1 to (N-1+K1) and horizontal addresses from K2 to (M-1+K2). That is, the pixel data, having addresses from (K1, K2) to (N-1+K1, M-1+K2) in the pixel memory 17, are selected and displayed on the screen of the monitor 18.
FIG. 6A shows an address setting for producing a vertically compressed image, and FIG. 6B shows the image displayed on the monitor 18 according to the address set shown in FIG. 6A. Here, the image mode setting unit 16 sets the image as a vertical compression mode, and the initial value setting unit 11 sets both the vertical and horizontal addresses of the reference pixel data to "0". The address selecting unit 14 sequentially generates horizontal addresses from "0" to (M-1) and vertical addresses starting from "0" and increasing by predetermined constant intervals. Here, the interval is set as 2. That is, when the pixel data of the pixel memory 17 is selected as described above, an original image is vertically compressed and displayed on the upper portion of the screen of the monitor 18.
FIG. 7A shows an address setting for producing a horizontally compressed image, and FIG. 7B shows the image displayed on the monitor 18 in accordance with the address set shown in FIG. 7A. Here, the image mode setting unit 16 sets the image as a horizontal compression mode, and the initial value setting unit 11 sets both the vertical and horizontal addresses of the reference pixel data to "0". The address selecting unit 14 sequentially generates vertical addresses from "0" to (M-1) and vertical addresses starting from "0" and increasing by predetermined constant intervals. Here, the interval is set as 2. That is, when the pixel data of the pixel memory 17 is selected as described above, an original image is horizontally compressed and displayed on the left side of the screen of the monitor 18.
FIG. 8A shows an address setting for producing a fully compressed image, and FIG. 8B shows the image displayed on the monitor 18 according to the address set shown in FIG. 8A. In this case, the image mode setting unit 16 sets the image mode as a full compression mode. The initial value setting unit 11 sets both the vertical and horizontal addresses of the reference pixel data as "0" and the address selecting unit 14 generates vertical addresses starting from "0" and increasing by first predetermined constant intervals and horizontal addresses starting from "0" and increasing by second predetermined constant intervals. Here, the first and second constant intervals are both set as being 2. That is, when the pixel data of the pixel memory 17 is selected as described above, an original image is horizontally and vertically compressed and displayed on the upper-left-most portion of the screen of the monitor 18.
FIG. 9A shows an address setting for producing a fully compressed screen with respect to an arbitrarily selected portion of an image, and FIG. 9B shows the image displayed on the monitor 18 according to the address set shown in FIG. 9A. In this case, the image mode is set as a full compression mode as in FIGS. 8A and 8B. However, both the vertical and horizontal addresses of the reference pixel data are set as being 20.
FIG. 10A shows an address setting for producing an expanded image, and FIG. 10B shows the image displayed on the monitor 18 according to the address set shown in FIG. 10A. In this case, the image mode setting unit 16 sets the image mode as an expansion mode. The initial value setting unit 11 sets both the vertical and horizontal addresses of the reference pixel data as "0", and the address selecting unit 14 sequentially selects both vertical and horizontal addresses starting from "0" and repeatedly generates the selected vertical addresses by a predetermined first repetition number and the selected horizontal addresses by a predetermined second repetition number. Here, the first and second repetition numbers (or repeating intervals) are both set as being 2, respectively. That is, when the pixel data of the pixel memory 17 is selected as described above, a partial original image is horizontally and vertically expanded and displayed on the screen of the monitor 18.
FIG. 11A shows an address setting for producing an expanded image of an arbitrarily selected image portion, and FIG. 11B shows the image displayed on the monitor 18 in accordance with the address set shown in FIG. 11A. In this case, the image mode is set as an expansion mode as in FIGS. 10A and 10B. However, both the vertical and horizontal addresses of the reference pixel data are set as being 20.
FIG. 12 shows an address setting for producing a moving image, wherein the upper row of illustration blocks each show an address setting for producing an image composed of (N×M) pixel data, and the lower row of illustration blocks each show which pixel data from the pixel memory 17 is accessed according to the address set shown directly above it. In this case, the image mode setting unit 16 sets the image mode as a moving mode. In the moving mode, pixel data corresponding to an original image stored in the pixel memory 17 is sequentially accessed and displayed so that the image on the screen of the monitor 18 moves by a predetermined interval of displacement upon incrementing the addresses.
According to the example of FIG. 12, the initial value setting unit 11 sets both the vertical and horizontal addresses of the reference pixel data to "0", and the address selecting unit 14 sequentially generates vertical addresses from "0" to (N-1) and horizontal addresses from "0" to (M-1) (shown in the left-most upper block of FIG. 12). That is, pixel data having addresses from (0, 0) to (N-1, M-1) in the pixel memory 17 (as shown in the left-most lower block of FIG. 12), is selected and displayed on the screen of the monitor 18. Next, the initial value setting unit 11 increases the vertical and horizontal addresses of the reference pixel data by one and the address selecting unit 14 sequentially generates an address capable of selecting (N×M) pixel data from the increased reference address. That is, pixel data of the pixel memory 17, accessed by the following addresses, are sequentially displayed on the screen of the monitor 18. The following is an example of the sequential address matrices according to the incrementing method.
(0, 0)×(N-1, M-1); (1, 1)×(N, M); (2, 2)×(N+1, M+1); . . . ; (20, 20)×(N+19, M+19); . . .
The progression of block from left to right in FIG. 12 illustrates this concept.
As described above, the video display controlling device of the present invention stores more pixel data than that capable of being displayed by a monitor and generates an address for accessing the pixel data of the memory, depending on the image modes, thus easily realizing functions such as image compression or extension in a video display device.
Although the present invention has been described with respect to a preferred embodiment, it will be appreciated that various modifications and changes may be made to the described embodiment without departing from the spirit and scope of the invention.
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Image transformation is performed via a video display controlling device. Image data is transformed from an image storage memory having a matrix size of (N+a)×(M+b) onto a display screen sized to display an image according to N×M size matrix. The video display controlling device operates according to any one (or a combination of) several image transformation modes, including a normal mode, an expansion mode, a compression mode, and a moving image mode. These transformations are accomplished by first setting vertical and horizontal addresses of a reference pixel among pixel data stored in the storage memory, and setting an image mode for transforming an original image in a predetermine pattern. Addresses are then generated, in accordance with the set reference pixel and the set image mode, for selecting an N×M set of pixel data from among the (N+a)×(M+b) pixel data in the storage memory.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 11/467,139, filed Aug. 24, 2006, now U.S. Pat. No. 8,177,662, which application is a continuation of Ser. No. 11/313,137, filed Dec. 20, 2005, now U.S. Pat. No. 7,189,169, which application is a continuation of Ser. No. 10/043,421, filed Jan. 10, 2002, now U.S. Pat. No. 7,004,852.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to golf clubs and, more particularly, to a golf club head in which the center of gravity, balance, and weight are customizable and can be altered to suit changing course conditions, weather conditions, and/or other user requirements.
2. Description of Related Art
Golfers have long recognized that they could alter the weight, balance, and performance characteristics by selectively adding weight to club heads. Typically, weight is added by applying thin strips of lead tape with an adhesive backing to the club head. In this manner the swing weight is increased and the center of gravity (CG) is altered to change the dynamics of the head during the swing and, therefore, the ball flight characteristics after contact. The location of the lead tape, however, is generally limited to the back, crown, and/or sole of the club heads where it would best stay affixed and not alter the look of the club, but this limits the adjustability options available to the golfer. For example, the lead tape could not be put on the face of the club to move the CG closer to the front of the club which is more desirable to some golfers who want the club to be easier to “work”, i.e., to shape shots both in a left-to-right manner and in a right-to-left manner.
Furthermore, this use of lead tape was generally an additive process whereby the swing weight and total weight of the club was increased, often times negatively effecting other performance characteristics of the club. Some golfers overcame this obstacle by grinding down or using other means to reduce the weight of the club. However, this often damaged the protective finish of the club or the shape and configuration intended by the club designer, negatively affected the after-market value of the club, and was difficult and time consuming for the golfer to adjust.
Furthermore, manufacturers of golf clubs have encountered problems when attempting to manufacture individual clubs to identical specifications because of variances of the individual components themselves and when assembled together. Generally, manufacturers build clubs to a weight at, or slightly below, a targeted weight specification and then add additional weight in the head and/or the shaft to increase the total weight and/or the swing weight to the desired specification. Additional weight is commonly added by pouring lead powder into the bottom of the shaft and sealing the shaft with a cork or other means. Alternatively, lead powder has been mixed with putty, epoxy, or other materials that are inserted into the end of the shaft of the assembled head and shaft to facilitate this final weight adjustment by the manufacturer. This method, however, alters the CG of the club away from the optimal location, adversely effecting performance and feel.
Additionally, a common practice has been to inject a hot melt glue or similar material into a hole in the club head during final assembly to arrive at a prescribed swing weight. The location that the glue puddles and adheres to the inner walls is determined by the orientation of the head while the glue is still hot and fluid. Furthermore, this technique has been used to customize the center of gravity of the club head for specific golfers' needs. The location of the glue, however, is generally limited to one broad area due to the closed process, and once the glue is set, the glue is not adjustable.
Several methods have been attempted to create a golf club that allows the weight, balance, and CG of golf club heads to be altered. One example is disclosed in U.S. Pat. No. 6,254,494 to Hasebe, et al. (hereinafter “Hasebe”), entitled, “Golf club head”. The weights, which effect CG location and club head dynamics during the swing and the ball flight after contact, can be changed during manufacturing. Once manufactured, however, the weights can not be altered or be customized for individual needs. Therefore, a club head must be manufactured for each desired weighting configuration.
Another example is disclosed in U.S. Pat. No. 6,248,025 to Murphy, et al. (hereinafter “Murphy”), entitled, “Composite golf club head and method of manufacturing”. Murphy discloses a weight strip within a ribbon of the body of the club head. Weights in the form of densified loaded films and/or ribbons of material denser than the primary composite material of the head are added to the internal structure assertedly to increase the forgiveness and playability characteristics, including the energy transfer. Murphy discloses that the location and configuration of the weights can be changed during manufacture to achieve varying characteristics, but, once the weights are added and the club head is completed in manufacturing, the weights can not be altered.
Yet another example is disclosed in U.S. Pat. No. 6,206,790 by Kubica, et al. (hereinafter “Kubica”), entitled “Iron type golf club head with weight adjustment member”. Kubica assertedly discloses a weight adjustment member located within a secondary cavity within the back of a cavity back iron golf club head. The weight adjustment member is said to be chosen from a plurality of weight adjustment members to overcome variances in manufacturing tolerances and to adjust golf club swing weights to custom fit various golfers' requirements. The weight adjustment member, however, does not allow the position of the CG to be altered.
Yet still another example is disclosed in U.S. Pat. No. 3,652,094, to Glover (hereinafter “Glover”), entitled, “Golf club with adjustable weighting plugs”. Glover assertedly discloses the use of threaded weight plugs to alter the CG. The location of the CG in Glover, however, is limited to the position of the threaded cavities. Similarly, U.S. Pat. No. 5,050,879 to Sun, et al. (hereinafter “Sun”), entitled, “Golf driver with variable weighting for changing center of gravity”, assertedly discloses three cavities that are sealed by a cover plate in the sole where weight members can be selectively installed. However, the user's options for the location of the weight members are limited to adjustment between the three predetermined cavities, in the horizontal plane from heel to toe, and near the sole only.
Yet still another example is disclosed in U.S. Pat. No. 6,306,048 to McCabe, et al. (hereinafter “McCabe”), entitled, “Golf club with weight adjustment”. McCabe assertedly discloses one or more weight chambers that the golfer uses to adjust the weight and CG of a club to customize it to his or her own needs. A filler material is used to set the weights in position. This method, however, limits the weights and weight changes to the location of the internal weight chamber, and, once the filler material is set, the golfer can no longer adjust the weight or center of gravity.
Therefore, there is a need for a golf club head with a customizable CG that allows the CG to be altered by a golfer and/or the manufacturer.
SUMMARY
This disclosure provides a metal golf club head that allows a user to customize the location of the center of gravity. The metal golf club head comprises hollow-body golf club head with a weighting port that allows the user to access the interior of the hollow-body golf club head. The weighting port allows a user to place weighting material, such as lead tape and the like, inside the golf club head, thereby customizing the location of the center of gravity.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a metal golf club head that embodies features of the present invention;
FIG. 2 illustrates a bottom view of a metal golf club head that embodies features of the present invention;
FIG. 3 illustrates a rear view of a metal golf club head with a weighting port cover removed that embodies features of the present invention;
FIG. 4 illustrates a cross-section view with the weighting port cover attached that embodies features of the present invention;
FIG. 5 illustrates a metal golf club head with the crown portion removed to indicate some positions of weighting material;
FIG. 6 illustrates a metal driver head embodying features of the present invention;
FIG. 7 illustrates a metal iron golf club head embodying features of the present invention;
FIG. 8 illustrates a metal putter head embodying features of the present invention; and
FIG. 9 illustrates an alternative embodiment of a golf club head.
DETAILED DESCRIPTION
Referring to FIG. 1 of the drawings, the reference numeral 100 generally designates a hollow golf club head embodying features of the present invention. The hollow golf club head 100 generally comprises a face portion 110 , an integrated sole and wall portion 112 , and a crown portion 114 defining a body 116 with an interior cavity 118 . A hosel portion 124 is connected to and/or integrated into the body 116 for receiving a shaft (not shown). Furthermore, a removable, port cover 120 , which is described in further detail below with reference to FIG. 3 , provides access to the interior cavity 118 , thereby allowing the placement of weighting material, such as lead tape, into the interior cavity 118 .
In the preferred embodiment, the hollow golf club head 100 comprises a two-piece golf club head. The first piece comprising the integrated sole and wall portion 112 and the face portion 110 , including the hosel portion 124 . The second piece comprises the crown portion 114 , which is welded or otherwise attached to the first piece. Other embodiments, such as a three-piece golf club head, however, may be used as is known in the art.
FIG. 2 is a bottom view of the hollow golf club head 100 , further illustrating the positioning and sizing of the weighting-port cover 120 in the preferred embodiment. Preferably, the weighting-port cover 120 is positioned on the bottom, i.e., the sole, of the hollow golf club head 100 and away from the face portion 110 . Therefore, the weighting-port cover 120 is preferably positioned such that the weighting-port cover 120 is not visible by a golfer when addressing a golf ball. Furthermore, the placement of the weighting-port cover 120 away from the face portion 110 allows placement of weighting material about, or on, the interior side of the face portion 110 , and along the heal/toe portions of the hollow golf club head 100 , as will be described in greater detail below with reference to FIG. 4 .
The weighting port cover 120 is preferably attached to the body 116 via a plurality of flush-mounted bolts 122 , and, optionally, may be coated with a friction-reducing material, such as Teflon. In order to reduce the friction, the possibility of the weighting-port cover to “snag” onto grass, thereby affecting the swing path, and the wear and tear, the weighting-port cover 120 is flush-mounted to the integrated sole and wall portion 112 by the plurality of flush-mounted bolts 122 .
FIG. 3 illustrates the hollow golf club head 100 with the weighting-port cover 120 removed. The body 116 preferably includes a recessed portion 310 configured for receiving an optional vibration-dampening ring 312 and the weighting-port cover 120 . The vibration-dampening ring 312 , such as a ring made from foam, rubber, and/or the like, allows the weighting-port cover 120 to be securely fastened, preventing a vibration/rattling noise that may occur as a result of swinging the club and/or striking a ball and sealing the interior cavity from exposure to outside elements, such as sand, water, and/or the like.
The plurality of flush-mounted bolts 122 pass through the weighting-port cover 120 and screw into the recessed portion 310 of the body 116 . Alternatively, other methods, such as a weighting-port cover that screws into the body 116 , latches, and/or the like, may be used. The preferred embodiment, however, allows for weighting-port cover 120 that is curved to match the contour of the body.
FIG. 4 illustrates a side view of the weighting-port cover 120 attached to the body 116 in accordance the one embodiment of the present invention depicted in FIG. 3 . As one skilled in the art will appreciate, the recessed portion 310 allows a smooth contour to be formed by the integrated sole and wall portion 112 and the weighting-port cover 120 when assembled. In an alternative embodiment, however, the weighting-port cover 120 is recessed from the integrated sole and wall portion.
FIG. 5 illustrates the hollow golf club head 100 with the crown portion 114 separated from the integrated sole and wall portion 112 in order to illustrate potential placements of weighting material in accordance with embodiments of the present invention. The illustrated positions are presented for illustrative purposes only and, therefore, should not limit the present invention in any manner. Furthermore, the positions may be used individually or in combination to further customize the location of the center of gravity.
Weight location 510 illustrates a low-front-center location, which is located on the integrated sole and wall portion 112 adjacent to the face portion 110 , that imparts less spin on the ball and a high trajectory, resulting in easier workability (the ability to hit the ball from left to right and vice versa) and more carry (the distance the ball travels in the air).
Weight location 512 illustrates a high-front-center location, which is located on the crown portion 114 adjacent to the face portion, that imparts less spin on the ball and a low trajectory, resulting in easier workability, less carry, and more rolling.
Weight location 514 illustrates a low-back-center location, which is located on the back-center of the integrated sole and wall portion 112 , that results in more forgiveness and a high trajectory.
Weight location 516 illustrates a high-back-center location, which is located on the back-center of the crown portion 114 , that results in more forgiveness and a low trajectory.
Weight location 518 illustrates a low-back-toe location, which is located on the back-center of the integrated sole and wall portion 112 along the toe, that results in more forgiveness and a high, fading trajectory.
Weight location 520 illustrates a high-back-toe location, which is located on the back-center of the crown portion 114 along the toe, that results in more forgiveness and a low, fading trajectory.
Weight location 522 illustrates a low-back-heel location, which is located on the back-center of the integrated sole and wall portion 112 along the heel, that results in more forgiveness and a high, drawing trajectory.
Weight location 524 illustrates a high-back-heel location, which is located on the back-center of the crown portion 114 along the heel, that results in more forgiveness and a low, drawing trajectory.
Weight location 526 illustrates a forward-center-center location, which is located on the center of the face portion 110 , that results in easier workability with a neutral trajectory.
Weight location 528 illustrates a back-center-center location, which is located in the vertical-center of the integrated sole and wall portion 112 , that results in neutrally forgiving club head.
Weight location 530 illustrates a low-center-center location, which is located on the center of the integrated sole and wall portion 112 , that results in a neutral side-spin with a high trajectory. Note that this location is located on the weighting-port cover 120 for illustrative purposes only. As stated above, the weighting-port cover 120 may be located at any desired location, and a weight may be placed on the weighting-port cover 120 if so desired.
Weight location 532 illustrates a high-center-center location, which is located in the center of the crown portion 114 , that results in a neutral side-spin with a low trajectory.
FIG. 6 illustrates a driver golf club head embodying features of the present invention in which the weighting-port cover 120 is located on the crown portion 114 .
FIG. 7 illustrates a hollow, iron golf club head embodying features of the present invention in which a weighting-port cover 710 is provided.
FIG. 8 illustrates a hollow, putter golf club head embodying features of the present invention in which a weighting-port cover 810 is provided.
It should be noted that the placement and size of the weighting port is shown for illustrative purposes only, and, therefore, should not limit the present invention in any manner.
FIG. 9 illustrates an alternative embodiment as described above wherein the weighting-port cover 902 screws into the body. In this embodiment, the cover 902 includes a substantially curved threaded outer perimeter 904 . A weight 906 attached to an inner portion of the cover 902 is shown in phantom. Reference numeral 908 is a seal, as has been described. The elements 902 , 904 , 906 and 908 comprise an assembly.
It is understood that the present invention can take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or the scope of the invention. For example, the weighting port may be of a different shape and/or there may be a different method of accessing the interior of the club head, such as removing the sole of the club head, the back of the club head, or the like.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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A metal golf club head that allows a user to customize the location of the center of gravity. The metal golf club head comprises a hollow body with a weighting port. The weighting port allows a user to place weighting material inside the hollow body, customizing the location of the center of gravity, the swing weight, the total weight, and the balance of the golf club.
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BACKGROUND OF THE INVENTION
The present invention relates to a burner, particularly a ceramic burner for use in the combustion shaft of a hot-blast stove, of the type including concentric chambers for the combustion media, e.g. combustion air and gas, which chambers are joined at an opening area of the combustion shaft, and a mixing element arranged centrally within such opening area.
Especially in hot-blast stoves having large dimensions, and which therefore are acted upon by large volumes of combustion media, it is extremely difficult to control the mixing of combustion air and combustion gas. This is particularly true since it is not possible to avoid variations in the burner load produced by variations in the heating value of the supply of combustion gas. Defective mixing as a preliminary stage for combustion again leads to an irregular combustion. There results an unstable burning which results in abnormal stresses, chiefly on the combustion shaft. When mixing is totally insufficient, combustion takes place in the form of constantly repeating explosion-type ignitions having distinct pressure amplitudes and oscillation periods. The burner pulsates noticeably. Such pulsation is propagated to the various parts of the hot-blast stove installations, e.g. the pipeline systems, and may produce considerable damage thereto.
German published application DT-OS No. 1,551,828/24c,10 discloses a hot-blast stove burner wherein the flow rate and the direction of flow of air and combustion gas are adjustably controlled in an attempt to secure an extensive mixing effect. Regulation is effected by means of an inner cone that is displaceable in the vertical direction, thereby widening the flow through the central burner chamber in an annular manner, and that is introduced into a similarly annular flow through an outer burner chamber. This arrangement does not however result in mixing and distribution of the air and combustion gas through the entire cross section of the combustion shaft at the opening of large volume hot-blast stove burners.
SUMMARY OF THE INVENTION
The object of the present invention is to improve the mixing effect, especially on large volume burners, while allowing variations in load and/or forces acting on the burner, insofar as such variations are within the scope of normal operationally caused variations of the combustion gas.
This object is achieved in accordance with the present invention by providing a disk-shaped mixing element, having therethrough a ring of passage openings extending substantially in the direction of flow, behind or downstream of a position of the burner whereat there is achieved at least a partial combination of the combustion media. Such a structure and arrangement of the mixing element produces more uniform flow rates together with strongly varying directions of flow, thereby resulting in an intensive mixing of air and combustion gas, so as to secure more stable combustion and to avoid disturbing pulsation.
The mixing element advantageously covers 25 to 40% of the cross-sectional area of the central burner duct, while the total cross-sectional area of the passages of the mixing element equals 10 to 30% of the total cross-sectional area of the mixing element. Even under differential loads of the burner, these surface ratios produce excellent mixing results, particularly in combination with the following further features of the invention. Specifically, the passages are arranged on a circle coaxial with the axis of the mixing element, with the central axes of the passages diverging outwardly in the direction of flow and being inclined up to 20° circumferentially of the circle. The height of each of the mixing element passages is 2.5 to 4 times the diameter thereof. The diameter of the circle is 50 to 70% of the outer diameter of the mixing element.
In burners employing two-stage combination of the combustion media, i.e. a primary and a secondary introduction of the annular flow of air into the concentric full-cross-sectional flow of combustion gas, the mixing element is expediently provided at the level of the second combination. The mixing element provides maximum mixing effect at such a position.
The mixing element in accordance with the invention has a convex upper surface and a plane lower surface. The plane surface provides a damming effect to the ascending media, and therefore the flow of the media through the passages of the mixing element is achieved at equal quantitative proportions, while the convex surface promotes the development of identical flow rates of all portions of the media.
The mixing element preferably is formed of a ceramic material body member and a metal base plate. Preferably, the mixing element is carried by a plurality of brickwork brackets extending inwardly from the wall of the central burner duct to the central axis of the burner, the mixing element being joined directly or indirectly to such brackets. Preferably, there are provided three brickwork brackets that divide the central burner duct in three similar longitudinal chambers each having a sectorial cross section. This arrangement provides the advantage of rendering uniform the flow through all portions of the cross section of the central burner duct.
In many cases, mainly involving the later incorporation of the mixing element into an existing hot-blast stove burner, it is of advantage to arrange the mixing element on a steel column, which is positioned at the longitudinal central axis of the burner by means of transverse and bottom anchors. This makes it possible to mount the mixing element in a simple manner, even when the hot-blast stove is stopped only for a short time.
When the mixing element is mounted on such a steel column, the mixing element may be provided with outlet nozzles, and the steel column may be provided with feed ducts for the supply of combustion media for a starting or pilot burner.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail below with reference to the exemplified embodiments thereof illustrated in the accompanying drawings, wherein:
FIG. 1 is a longitudinal section of a novel ceramic burner which is arranged in the base of the combustion shaft of a hot-blast stove and which is equipped with a mixing element;
FIG. 2 is a plan view of the central portion of FIG. 1;
FIG. 3 is a longitudinal section, on an enlarged scale, of the mixing element of the burner of FIGS. 1 and 2;
FIG. 4 is a plan view of the mixing element of FIG. 3;
FIGS. 5 and 6 are views similar to FIGS. 1 and 2, respectively, of a second embodiment of the invention;
FIG. 7 is a view similar to FIGS. 1 and 5 of a third embodiment of the invention;
FIG. 8 is a section, on an enlarged scale, of the mixing element arrangement of the burner of FIG. 7; and
FIG. 9 is a further enlarged detail view of the area A of FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1 and 2, a combustion shaft 1 of a hot-blast stove includes a refractory brickwork 2 and a sheet metal casing 3 surrounding the brickwork 2. A burner of refractory material is arranged in the base of combustion shaft 1 and includes a duct 4 concentric to the axis of the combustion shaft 1, and an annular duct 6 which is separated from duct 4 by an annular wall 5 and which is defined on the outer side or surface thereof by brickwork 2 of combustion shaft 1. Ducts 4 and 6 are provided with feed ducts 7 and 8, respectively. Feed ducts 7 and 8 respectively supply combustion components or media to ducts 4 and 6 and are oriented transversely to the longitudinal axes of ducts 4 and 6. Feed duct 7 of central duct 4 is arranged at the bottom of combustion shaft 1, while feed duct 8 associated with annular duct 6 is situated above feed duct 7. Each burner duct 4 and 6 is provided with a constriction orifice 9 and 10, respectively, which are formed by projections of the respective brickwork. Orifice 9 of central duct 4 is formed by brickwork wall 5 projecting inwardly in the form of a first ring nozzle having openings 11 therethrough which connect annular duct 6 to central duct 4. Above constriction orifice 10 at the top portion of annular duct 6, there is situated a second ring nozzle having openings 12 therethrough which also connect annular duct 6 to central duct 4 at a position above openings 11. Above openings 12 is burner opening 13 which widens upwardly toward the wall of combustion shaft 1.
Within duct 4, at approximately the vertical height of openings 12, and along the central longitudinal axis of the burner is a mixing element 15 supported by a column 16, which is supported by brickwork brackets 17 extending from the wall of central duct 4 inwardly toward the central longitudinal axis of the burner. In the illustrated arrangement there are provided three brickwork brackets 17 arranged in the form of a star and dividing central duct 4 in three identical conducting sections 4'.
As seen most clearly in FIGS. 3 and 4, mixing element 15 has the shape of a round disk comprising a convex top surface 18 and a plane base surface 19. Mixing element 15 includes a metal base plate 20 and a refractory top body member 21. Mixing element 15 has a plurality, e.g. eight, passage openings 22 extending therethrough. Openings 22 are all arranged around the circumference of a circle 23 concentric with the vertical central axis of mixing element 15, preferably with the axes of openings 22 at the upper ends thereof intersecting circle 23. Openings 22 each diverge upwardly and outwardly from base surface 19 to top surface 18, and openings 22 are also inclined in the circumferential direction of circle 23. Thus, a curved surface including the axes of openings 22 will be in the form of an upwardly widening cone. Perferably, the angle of inclination of the sides of such cone to the central longitudinal axis of mixing element 15 is 10° to 20°. Also preferably, the angle of inclination of the axes of openings 22 to radial planes through the central longitudinal axis of mixing element 15 is 10° to 20°.
The horizontal area of mixing element 15 preferably covers 25 to 40% of the horizontal cross-sectional area of the central burner duct. The total horizontal cross-sectional area of openings 22 equals 10 to 30% of the total horizontal cross-sectional area of mixing element 15. The height of each opening 22 is 2.5 to 4 times the diameter thereof. The diameter of circle 23, located on top surface 18, is 50 to 70% of the outer diameter of mixing element 15.
The above dimensional limitations and features produce excellent mixing of the combustion media by the mixing element 15.
The above described burner operates in the following manner.
Combustion gas flows through feed duct 7 into central burner duct 4, and combustion air flows through feed duct 8 into annular duct 6. When ascending in central duct 4, all of the combustion gas is oriented in the same direction of flow along brickwork brackets 17 and is distributed with uniform density throughout the cross section of flow by constriction orifice 9. The air flow in annular duct 6 is similarly subjected, by constriction orifice 10, to a uniform density distribution and to compression throughout the cross section of flow. Therefore, a first combination of air and combustion gas is effected at the first ring nozzle as a partial amount of air which flows over from annular duct 6 through openings 11, with the flow through the various openings being equal and uniform.
The first gas mixture produced at the first ring nozzle flows upwardly and passes mixing element 15, which exerts a damming effect on the flow. A partial quantity of the gas mixture flows past mixing element 15 around the periphery thereof, while the remaining fraction of the gas mixture passes through passage openings 22. The peripheral annular flow around mixing element 15 is admixed with the residue of combustion air arriving from constriction orifice 10 through openings 12 in the second ring nozzle to form a second gas-air combination or mixture, while the fraction of the first gas mixture passing through passage openings 22 exits therefrom in the form of a diverging annular fan of gas mixture jets. Due to this configuration, such fraction of the first gas mixture is intimately mixed with the second gas mixture produced between mixing element 15 and the second ring nozzle, so as to form a homogeneous mixed flow distributed uniformly through the cross section of the burner opening.
FIGS. 5 and 6 illustrate a second embodiment of the burner wherein, as a modification of the burner of FIGS. 1 and 2, a mixing element 25 is directly mounted in brickwork brackets 26, two passage openings 27 being provided through mixing element 25 between each pair of adjacent brackets.
In a third embodiment of the invention, as shown in FIG. 7, a mixing element 30 is mounted on and supported by a metal, e.g. steel, column 31 positioned at the central longitudinal axis of the burner. This embodiment has no brickwork brackets 17 or 26. Column 31 is supported by transverse ties or anchors 32, 33 and 34, and column 31 extends to the exterior of combustion shaft 1 through the bottom thereof. Column 31 is further supported by a bottom anchor 35 provided in the bottom area of the combustion shaft, and a flange coupling 36, still further supporting column 31, is attached to sheet metal casing 3 exterior of the combustion shaft. Upper transverse anchor 32 extends through an opening 11 of the first ring nozzle and abuts against the wall of refractory brickwork 2, while anchors 33 and 34 contact the wall of central combustion shaft 4.
As shown in FIGS. 8 and 9, a mixing element 30 and a steel column 38, in accordance with the invention, may be constructed as a pilot or starting burner. Column 38 is in the form of a double pipe, wherein fuel is fed through an inner pipe 39, while combustion air is fed through annular space 40 between an outer pipe 41 and inner pipe 39. Pipes 39 and 41 are provided with respective constriction orifices 42 and 43, each of which end in a mixing chamber 44 provided centrally within refractory body member 37 of mixing element 30. A nozzle plate 45 is imbedded within body member 37 and connects mixing chamber 44 with the combustion shaft. Plate 45 is fastened to body member 37, e.g. by means of tap bolts and anchors 46, such as shown in FIG. 9.
It is to be understood that modifications may be made to the above specifically described structural arrangements without departing from the scope of the present invention.
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A burner includes a central burner duct for passing combustion gas therethrough and an outer annular duct for the passage of combustion air and coaxial to the central burner duct. The ducts open or join at an opening area, upstream of which are one or two areas where the combustion gas and air are combined or brought together and mixed. A disk-shaped mixing element is positioned within the opening area centrally thereof and downstream of the first combination area and adjacent the second combination area. The mixing element has extending therethrough substantially in the direction of flow, a ring of separate passages.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a method and a corresponding system for checking the color quality of preforms intended for the manufacture of containers, in particular beverage bottles. In particular the present invention relates to a method and a corresponding system for checking the color quality of preforms, in which the preforms are transported by a transport device into a collection vessel by a transport device, and an image being made of the preforms by means of an imaging device and being transmitted to a processing device for checking.
[0002] It should be mentioned here that the term “preform”, used in the following, is not to be understood in a limiting way. In particular this term covers all pieces used for the manufacture of containers, for instance beverage bottles, but also all similar objects the production methods for which or respectively the structure and/or appearance of which are similar to the conventional preforms. Examples of such objects include in particular syringes (for medical or laboratory use), test tubes, cuvettes, etc. It is also possible to use this invention in the same way with other products, e.g. with plastic caps, among other things.
STATE OF THE ART
[0003] In the manufacture of containers, in particular beverage bottles, first used generally are so-called preforms, i.e. premoldings or blanks, and these preforms are then further processed into finished containers. These preforms are typically made of plastic, above all PET (polyethylene terephthalate). Other, similar articles, such as the above-mentioned syringes, test tubes, cuvettes, etc. but also plastic caps, among other things, are made in a similar way.
[0004] Because manufacturing processes are energy-intensive and because, as a rule, the manufacturing processes have to be stopped upon discovery of preforms that are not flawless (incurring higher costs), manufactured preforms as well as other mentioned preform-like articles are checked as a rule before they are sent to further processing. Possible defects in the manufactured preforms are above all imprecise dimensions, irregular shape, too thin or too thick wall areas, pin holes, burns, presence of foreign bodies and/or bubbles, but also deficient color quality.
[0005] Various systems and methods are known for checking preforms for these defects. In particular checking with the aid of digital imaging devices has become established. Preforms are thereby led past an imaging device so that one or more images of each preform are able to be made. An electronic processing device compares the images made with a reference image and determines whether it has certain defects. Reference values relating to non-conformance with quality standards lead to the elimination of the preform.
[0006] Common to all the previously known systems or respectively methods is that the objects to be checked have to be arranged and aligned so that the images of each object are able to be made in the desired position. In this way defects can be discovered very accurately and quickly. However this means that the examination of the objects to be checked cannot be carried out already in the manufacturing machine, but instead a separate checking system is always necessary downstream from the manufacturing machine. This once again means that the installation and the interface between the two systems are complex, and that they are only able to be achieved using qualified personnel. Moreover such checking systems require additional space, which is not always available with existing manufacturing machines.
DISCLOSURE OF INVENTION
[0007] Thus the object of the invention is to propose a method of checking the color quality of preforms as well as a system suitable for carrying out this method, in which the above-described drawbacks of the known methods and systems are completely overcome or at least greatly diminished.
[0008] In particular an object of the invention is to propose a method and the corresponding system for checking the color quality of preforms, thanks to which a reliable, quick and very easy automated checking of the color quality of a preform series is ensured with very little space requirements. Moreover the installation of this system should be able to be carried out very simply also on the existing manufacturing machines.
[0009] According to the present invention these objects are achieved in particular through the elements of the two independent claims. Further advantageous embodiments follow moreover from the dependent claims and the description.
[0010] In particular these objects of the invention are achieved in that, in the method of checking the color quality of preforms intended for the manufacture of containers, in particular beverage bottles, the preforms being transported by a transport device into a collection vessel, and an image of the preforms being made by an imaging device and being transmitted to a processing device for checking, the preforms are led in an unordered way into a collection vessel upon leaving the transport device, the image being made between the leaving of the transport device and the collection vessel, and the image being processed by the processing device in such a way that the color quality of the preforms is checked and/or defective preforms discovered.
[0011] Understood by unordered is thereby, for the time being, any type of order such as, for instance, the spacing to individual preforms with respect to one another and the alignment of the preforms in two-dimensional or three-dimensional space. Also to be understood as unordered is when the preforms have an irregular alignment to one another in one direction only.
[0012] The advantage of this invention lies in particular in the defective preforms being able to be discovered very simply, also in particular without their having to be specially aligned. Moreover hardly any adaptation to the existing facilities for preforms is required.
[0013] In one embodiment of this invention, the preforms are led in free fall into the collection device after leaving the transport device. This embodiment of this invention has inter alia the advantage that no additional feed devices have to be provided. Moreover the preforms can be received completely without their being partially or completely covered by any delivery devices.
[0014] In another embodiment of this invention the image of the preforms is made in front of a projection screen or a plate. The advantage of this embodiment is that the background in the pictures is able to be designed as individually so that an optimal evaluation is possible. In practice, undesired flaws owing to irrelevant elements can be completely excluded thanks to this embodiment.
[0015] Preferably the projection screen or the plate have a color having a good contrast to the color of the preforms. A good contrast is present if the colors of the preforms and of projection screen or plate are differ sufficiently so that a clear determination can be made about the color quality of the preforms or defects can be recognized. Concretely, the color of the plate can be white in many cases, but also other colors (such as black, for example) are absolutely conceivable. Likewise it is easily possible to take a metal-colored plate (e.g. stainless steel color). Thanks to the good contrast between the colors of the preforms and the color of the projection screen, or respectively of the plate, preforms are able to be especially well identified in the pictures taken, which leads to a better and faster evaluation of the image.
[0016] On the other hand it is also possible to use an at least partially transparent projection screen or respectively plate. For example, a glass window can be provided in such a non-transparent projection screen or respectively plate. The advantage of such a projection screen or respectively plate is the possibility of adapting the background of the images. Moreover the transparent area of the projection screen or respectively plate is able to be used for illumination of the preforms.
[0017] In still another embodiment of this invention attachment means are provided, thanks to which the projection screen, or respectively plate, can be positioned. This embodiment of the present invention has in particular the advantage that the projection screen or respectively plate (i.e. in particular also the inclination with respect to the perpendicular, as will be explained in the following) can also be adjusted depending upon the position of the imaging device in order to be able to ensure an optimal evaluation of the pictures taken.
[0018] In still another embodiment of the present invention, pluralities of images are evaluated in order to determine a flawless series of preforms. The advantage of this embodiment is that a statistically relevant number of pictures may be taken before a defect is determined. A certain tolerance in the evaluation can thereby be taken into account.
[0019] In another embodiment of this invention, the preforms are illuminated by means of at least one lighting fixture when making the image. The advantage of this embodiment is above all that when taking the pictures of the preforms to be checked a sufficient illumination of the preforms may be ensured. A good picture quality can thereby be guaranteed, which leads to a better evaluation of the images.
[0020] Preferably the at least one lighting fixture is positioned behind the projection screen or respectively the plate so that the preforms are illuminated from behind with respect to the imaging direction. Thanks to an illumination from behind (in relation to the direction of view of the imaging device) the preforms can be well illuminated, whereby the various deficiencies may also be detected much more easily and much more precisely. To this end the lighting fixture can be disposed advantageously behind the transparent region of the projection screen or respectively plate.
[0021] In another embodiment of the present invention, preforms slide over the plate, after leaving the transport device, in such a way that they are led into the collection vessel. Thanks to this plate the preforms can be channeled, on the one hand, and, on the other hand, they can be brought into one plane, it being possible for them to continue to be unordered in this plane. They can e.g. be e.g. at different spacings or in different alignment. This embodiment of the present invention has inter alia the advantage that the preforms are positioned optimally with respect to the imaging device, without special alignment devices having to be used. The preforms are aligned at a defined spacing to the imaging device. Moreover this plate also serves as the background in the pictures, as described above, so that an optimal evaluation of the image is made possible.
[0022] In another variant of the present invention the plate is perforated and is designed, for example, as a perforated plate. The use of such a plate has the advantage that the weight of the plate and of the entire facility can be reduced without the functionality of the plate becoming lost.
[0023] In a further variant of the present invention at least a portion of the plate is curved at least in one direction. For example, the curvature can extend transversely to the direction of the sliding of the preforms. Preferably it is possible for the plate to be curved in such a way that at least one channel is formed for the sliding preforms. In this way the sliding characteristics of the preforms may be better influenced, and it can be ensured that all preforms slide over a certain region of the plate. It is thereby possible to configure the taking of the picture of the sliding preforms more precisely since the distribution of the preforms in front of the imaging device can be limited in a further dimension. Thus with a channel-shaped plate the sliding preforms can be partially ordered so that the evaluation of the images can be made in a simpler and faster way.
[0024] It should still be mentioned here that, in addition to the above-described method of checking the color quality of preforms, the present invention also relates to a corresponding system.
[0025] The invention has been presented with reference to a plurality of embodiments. The individual technical features of one embodiment can by all means be also used in combination with another embodiment with the presented advantages. The description of the inventive technical features are therefore not limited to the respective embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Embodiments of the present invention will be described in the following with reference to examples. The examples of the embodiments are illustrated by the following attached figures:
[0027] FIG. 1 shows schematically a lateral view of a system for checking the color quality of preforms according to a first embodiment of the present invention.
[0028] FIG. 2 shows the system illustrated in FIG. 1 for checking the color quality of preforms in a view in perspective from the front.
[0029] FIG. 3 shows schematically a lateral view of a system for checking the color quality of preforms according to a second embodiment of the present invention.
[0030] FIG. 4 shows the system illustrated in FIG. 2 for checking the color quality of preforms in a view in perspective from the front.
[0031] FIGS. 5 a and 5 b show schematically a representation of a possible image, made for checking the color quality of preforms by an imaging system in the system of FIG. 1 or respectively FIG. 3 and evaluated by a processing unit.
[0032] FIG. 6 shows schematically a view in perspective from the front of a system for checking the color quality of preforms according to another variant of the second embodiment of the present invention.
[0033] FIG. 7 shows schematically a representation of a possible image for checking the color quality of preforms by an imaging system in the system of FIG. 6 and evaluated by a processing unit.
[0034] FIG. 8 shows schematically a view in perspective from the front of a system for checking the color quality of preforms according to still another variant of the second embodiment of the present invention.
[0035] FIG. 9 shows schematically a representation of a possible image for checking the color quality of preforms made by an imaging system in the system of FIG. 8 and evaluated by a processing unit.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0036] Illustrated in FIG. 1 and FIG. 2 is schematically a first embodiment of a system 1 for checking the color quality of preforms according to one embodiment of the present invention.
[0037] The preforms 2 produced in a conventional manufacturing machine or respectively in a conventional manufacturing system of plastic (e.g. PET) are transported unordered by the transport device 3 to a collection vessel 4 . Understood by the term unordered should be an arrangement of preforms that results “naturally”, i.e. without a previous ordering or respectively sorting. Of course it is also conceivable that the preforms 2 are passed on by the transport device not to a collection vessel 4 , but to a further transport device. However the present invention also works the same way also in this alternative case. The transport device 3 in FIGS. 1 and 2 is a conventional conveyor belt with a drive roller 3 a, which is driven via a drive (not shown). It is however conceivable of course to use another suitable transport device, for example a vacuum system or a gripping device.
[0038] After leaving the transport device 3 the transported preforms 2 reach a collection vessel 4 (indicated schematically). The collection vessel 4 can thereby be a simple cardboard box that is closed by the operating personnel after being filled and is carried away, or a more complex collection vessel, however, that can be used automatically or semi-automatically for packaging and storage of preforms 2 . Instead of the collection vessel 2 a further conveyor belt, a so-called cooling belt or another similar device can be foreseen. This is then used in particular when the examined preforms 2 must be subjected to another check and/or treatment.
[0039] As can be seen very well with reference to FIGS. 1 and 2 the preforms 2 are unordered during transport on the conveyor belt 3 as well as during the entry into the collection vessel 4 . In other words, the preforms 2 are brought directly out of the manufacturing machine with an alignment or an ordering onto the conveyor belt and in this state are transported to the collection vessel 4 . However, if the preforms 2 happen to come out of the manufacturing machine in an ordered way then it could also occur that they are also transported on the conveyor belt also in this ordered way. Clearly the present invention would also function in such a situation flawlessly, but it is in no way dependent upon such an alignment or respectively ordering.
[0040] Shown on the right-hand side in FIG. 1 or respectively in FIG. 2 is an imaging system 6 . This can be a very conventional digital camera, for instance, but the invention is not limited thereto, and one skilled in the art will readily know other imaging systems that can be used instead of the conventional digital camera. The imaging system 6 is connected to a processing unit (not shown).
[0041] The preforms 2 transported generally unordered on the transport device 3 leave this transport device 3 likewise in an unordered way and then fall (through the effect of gravity) into the collection vessel 4 . At this moment, i.e. precisely between leaving the transport device 3 and falling into the collection vessel 4 an image is made in each case of the preforms 2 falling past by the imaging system 6 and is transmitted to the processing device for checking. It is also conceivable for a series of several pictures to be made instead of a single image, so that in each case the taken picture for checking can be selected, in which at least one representative number of imaged preforms 2 to be checked has the optimal position. On the basis of this representative number then a determination may be made with respect to the total number of preforms.
[0042] In the first embodiment shown in FIGS. 1 and 2 a projection screen or respectively a screen device can be provided behind the falling preforms 2 (seen from the viewpoint of the imaging system 6 ), the function of which will be explained later. However it is also conceivable to achieve this first embodiment of the invention without the projection screen 5 .
[0043] Illustrated in FIG. 3 and FIG. 4 is schematically a system 1 for checking the color quality of preforms according to a second embodiment of the present invention. Same parts and installations corresponding to those of the first embodiment and having the same function are accorded the same reference numerals.
[0044] The preforms 2 transported basically in an unordered way on the transport device 3 leave this transport device 3 likewise in an unordered fashion and then reach a plate 5 ′, over which they are able to slide (in particular through the influence of gravity), in order to be introduced into the collection vessel 4 . During the sliding on the plate 5 ′ the preforms 2 are also unordered, but all are situated in one plane of the plate 5 ′. Thus during the sliding on the plate 5 ′, i.e. between leaving the transport device 3 and falling into the collection vessel 4 an image is made in each case of the preforms falling past by the imaging system 6 and is transmitted to the processing device. It is also conceivable to do a plurality of pictures instead of a single image so that in each case that taken image may be selected for checking in which the imaged preforms 2 to be checked have the optimal position.
[0045] One image is illustrated schematically in FIGS. 5 a and 5 b made with the system according to the first or respectively second embodiment of the invention. Images of a plurality of preforms may be identified in this picture. The projection screen can be seen in FIG. 5 a , and the plate 5 ′ in FIG. 5 b , in the background of the picture. In FIGS. 5 a and 5 b the images of preforms bear the reference number 7 (instead of 2 ) so that they are able to be distinguished from the “genuine” preforms. In other words, the preforms designated by 7 represent preforms that are representative for all preforms. The preforms 7 are in an area in front of the projection screen 5 that is suitable for obtaining images suitable for evaluation using the processing device. The area is defined e.g. by a spacing to the imaging system 6 .
[0046] In the image, given by way of example, according to FIG. 5 a it can be seen that the preforms 7 are unordered. In this sense the image of certain preforms 7 is incomplete under certain circumstances, since they are completely or partially covered by other preforms 7 . Moreover it can be seen that some preforms 7 in the picture taken are at an angle with respect to the projection screen 5 (or respectively with respect to the plane that is perpendicular to the angle of view of the imaging system 6 ) whereby one portion of their surface can be seen in the picture. In an extreme case it is conceivable that during free fall a preform 7 is located exactly in the angle of view of the imaging system 6 . In this situation only the image of the preform head or respectively of the preform floor would be able to be seen in the corresponding picture.
[0047] As can be seen in FIG. 5 b , in the case of a plate 5 ′, all preforms 7 lie in the same plane, i.e. in the plane of the plate 5 ′, so that they are always situated at an optimal angle with respect to the imaging system 6 . It can thereby be guaranteed that a large number of pictures taken of the preforms 7 can be used for evaluation.
[0048] The projection screen 5 can be made up of various materials, for instance plastic or textile. The plate 5 ′ can likewise be composed of many materials, for example plastic, glass or metal, but also of a combination of materials.
[0049] Preferably the projection screen 5 and the plate 5 ′ have a color such that a good contrast to the color of the preforms results. White is a good choice for many preform colors, but it is also conceivable also to use other colors, such as for instance black (for the checking of yellow preforms 2 ). A metal-colored projection screen or plate 5 ′ (e.g. of stainless steel) is also conceivable. Moreover the projection screen 5 or plate 5 ′ can also be designed at least partially transparent, for example in that it has a transparent area (in a manner of speaking a window). This transparent area can be made in a metal plate, for example, but other variants are absolutely conceivable. Finally the plate 5 ′ can also be perforated, or consist of a perforated sheet.
[0050] For attachment or respectively correct positioning of the projection screen 5 or plate 5 ′ special attachment means can be foreseen (not shown), for example frames or hanging hooks. In particular it is possible and advantageous to provide such attachment means with which the plate 5 ′ can be attached directly to the transport device 3 .
[0051] Visible in FIGS. 3 and 4 is also a lighting body 8 behind the plate 5 ′. It is practical if the lighting body 8 is positioned in such a way that the preforms 2 sliding on the plate 5 ′ are illuminated through the transparent area of the plate 5 ′. Thanks to the lighting body 8 , preforms 1 can be illuminated from behind in relation to the imaging system 6 in any case. Such a lighting body 8 is likewise conceivable for an embodiment with a projection screen 5 .
[0052] The images made are transmitted from the imaging system 6 to the processing device. The images for checking the color quality of preforms are subsequently evaluated by this processing unit. Concretely, in each evaluated image, first one or more preforms 7 are identified which were aligned during taking of the picture such that their whole length may be seen completely as completely as possible. These preforms 7 can be compared, for example, with a reference image of a correct preform in order to check the color quality of the preform 7 to be imaged. Thus, according to the invention, the correctly situated preforms with respect to position, angular position, overlapping parts, etc. are automatically detected in the picture taken so that they are each able to be compared with a reference image.
[0053] In the case of the first embodiment with a projection screen, e.g. those preforms are identified which, in free fall and during the taking of the picture were aligned at a certain direction with respect to the projection screen that their entire length in the image can be seen as completely as possible. Concretely it can be said that those preforms 7 are to be identified the longitudinal axis of which (at the moment of taking the picture) is situated at least parallel to the projection screen 5 . In FIG. 5 a the preforms having the reference numerals could be searched for.
[0054] In the case of the second embodiment with a plate 5 ′ those preforms are identified which are completely imaged, i.e. which lie completely covered in the picture region and are not covered by other preforms. With deviations from the reference picture (e.g. in the case of too great or too weak a coloring of the preform 7 ) a defective color of the preform can be directly detected. Instead of a reference picture in the narrower sense, it is also conceivable to use certain characteristic reference values, which, with the imaged preforms to be checked, are then compared with respect to the corresponding measurement results.
[0055] This method makes it possible, depending on the circumstances, not to subject all preforms 7 to examination since, seen statistically, there can also be such preforms 2 that during sliding are situated in such a way between the transport device 3 and the collection vessel 4 that their image cannot be very well evaluated in the described way. In an extreme case it is moreover thoroughly conceivable that no single image of preforms 2 is aligned in one picture such that its evaluation is possible by the processing device. Nevertheless these drawbacks can be taken into account since the color quality of all preforms 2 in the same series are normally identical or nearly identical so that the evaluation of a certain number of preforms 7 is completely sufficient in order to be able to determine the color quality of the whole series.
[0056] In this connection it is also thoroughly conceivable that the evaluation of each image is used directly in order to decide upon the color quality of a preform series. On the other hand it is also thoroughly possible that first a multiplicity of taken pictures must be evaluated before a conclusion about the color quality of the entire series may be made. Moreover it should be mentioned here that thanks to the present invention not only deficiencies in the color quality of preforms are able to be detected, but also many other possible defects, such as air bubbles, burns, soiling and the like. Thus the present description of the invention should not be interpreted in a limiting way.
[0057] According to the invention, it is moreover possible to offer the imaging system 6 , the respective processing device, the projection screen 5 or respectively the plate and the corresponding attachment means in each case together as a kit. In this case these elements could be installed by a person not specifically trained on a conventional manufacturing machine or respectively on a conventional manufacturing machine for preforms in a simple way and could be put into operation. Thanks to this possibility no adaptations in the manufacturing machine itself would have to be carried out.
[0058] Shown in FIGS. 6 to 9 are a second and a third variant of the system according to the second embodiment of the present invention. The 4 systems according to the present invention differ from the system illustrated in FIGS. 3 and 4 only in that the plate 5 ′, via which the preforms 2 slide after leaving the transport device 3 and before entry into the collection vessel 4 , are not designed flat. For this reason the elements in FIGS. 6 to 9 bear the same reference numerals as the elements in FIGS. 1 to 4 .
[0059] Concretely the plate 5 ′ in the system according to the second variant of the invention ( FIGS. 6 and 7 ) is curved in such a way that it is designed channel-like or trough-like. As can be seen very well in FIG. 6 , the plate 5 ′ has a shape making it possible in principle for all preforms 2 during the sliding to collect in the middle of the plate 5 ′ and the plate 5 ′ to be left in the middle of the lower rim. In this way the position or respectively the focus of the imaging system 6 may be adapted so that the pictures of the sliding preforms 2 are able to be made in an optimal way. Also the sliding performs 2 are partially sorted owing to the curved shape of the plate 5 ′, i.e. they align themselves necessarily in such a way that their longitudinal axes are disposed parallel to the direction of slide. Also this fact contributes to the taking of the pictures of the preforms 2 to be evaluated and their evaluation being able to be optimized. At the same time the preforms are unordered such that different spacings may arise or the preforms may have a surface in opposite directions.
[0060] Of course it is also conceivable for the curvature of the plate to be disposed or respectively designed in a different way, as is shown in FIG. 6 . One skilled in the art will however know how the curvature of the plate 5 ′ may be adapted to the special requirements.
[0061] In particular it is also conceivable that not the entire plate 5 ′ has a curvature. Such a variant is shown in FIGS. 8 and 9 . In contrast to the variant shown in FIGS. 6 and 7 , the plate 5 ′ in FIG. 8 has a curved area 5 a and a flat area 5 b. With this variant, the advantages of the systems according to the first embodiment ( FIGS. 1 and 2 ) and the second embodiment ( FIGS. 3 and 4 ) of the present invention may be combined. With this variant it is thus especially advantageous if two imaging systems 6 are provided, each making images of preforms 2 in one of the two areas 5 a and 5 b of the plate 5 ′. Such a double configuration is also possible however in other cases.
[0062] Moreover it would be possible in still another embodiment of the present invention for images of the preforms 2 to be made by the imaging system 6 not just before leaving the transport device 3 (thus while the preforms 2 are in free fall), but beforehand, still during transport of the preform on the transport device 3 ). For this purpose the imaging system 6 can be disposed over the transport device 3 , so that it is directed on the upper side of the transport device 3 . Images of the preforms 2 transported on the transport device 3 can then be made by the transport device being deigned completely or partially transparent so that a sufficient illumination of the preforms 2 is possible. The pictures of the preforms 2 taken in this way correspond substantially to the images taken with or without projection screen 5 in free fall or the pictures taken during the sliding on the plate 5 ′ so that the subsequent evaluation may be carried out in the same way.
[0063] It should be mentioned here that the present invention is not limited to the embodiment described. It will be clear to one skilled in the art that further developments and changes within the scope of the protected invention are easily possible. Thus, for example, system elements may be replaced, as needed, by other elements fulfilling the same (or similar) functions. It is also conceivable for the following method or respectively the following system to be used not exclusively for checking the color quality of preforms, but to check any other qualities. Likewise additional devices and/or elements could be provided, for example a multiplicity of imaging devices could be provided by means of which the preforms 2 to be checked may be imaged from different sides. Such measures and adaptations come however within the scope of protection of the invention defined by the following claims.
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The present invention relates to a method and the corresponding system for checking the color quality of preforms ( 2 ) intended for the manufacture of containers, in particular beverage bottles, the preforms ( 2 ) being transported to a collection vessel ( 4 ) by a transport device ( 3 ), and an image of the preforms ( 2 ) being made by means of an imaging device ( 6 ) and being transmitted to a processing device for checking, in which the preforms ( 2 ) are led unsorted into the collection vessel ( 4 ) upon leaving the transport device ( 3 ), the image being made between the leaving of the transport device ( 3 ) and the collection vessel ( 4 ), and in which the image is processed by the processing device in such a way that the color quality of the preforms ( 2 ) and/or defective preforms ( 2 ) are discovered.
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FIELD OF THE INVENTION
The present invention relates in general to bath alcoves and, more particularly, to an integrated bathtub and alcove construction.
BACKGROUND OF THE INVENTION
Description of the Prior Art
Heretofore, there have been numerous efforts to develop bathtub surrounds being generally of multi-panel construction with various means for endeavoring to mutually align and effectively interrelate such panels to bring about an attractive assembly with an independently installed bathtub. One such prior effort is revealed in Moore U.S. Pat. No. 3,740,908 which discloses a bathtub surround comprised of a back panel and side panels demonstrative of an effort to provide mutual adjustability for accommodating the particular structural recess receiving same. But expectedly there is no suggestion therein of any predetermined, interconnected relationship of such components with the bathtub.
Moore U.S. Pat. No. 3,845,600 also pertains to the provision of a surround, which consists of a biased wall panel of unitary, construction for permitting forceful adjustment of the inherent portions thereof for acceptance within the particular room opening. But here again, the thrust was to provide a surround devoid of any predetermined physical integration with a bathtub.
Reference may also be made to an earlier structure as shown in U.S. Pat. No. 3,564,788 wherein again the particular interconnection of the back panel and side panels of a surround constitute the inventive contribution; without suggestions as to any physical interengagement with the bathtub.
The foregoing thus exemplify that the teachings of the prior art have failed to reveal the inter-assembly of a bathtub and its surround, with all expected attendant benefits therefrom.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an integrated bathtub and alcove construction wherein the component members are physically interconnected so as to present a unified construction.
It is another object of the present invention to provide a bathtub and alcove construction wherein the bathtub serves fundamentally as an anchor for the surround so that the latter's relationship to the bathtub is of positive character; with the resulting ensemble being of overriding importance as distinguished from prior art structures wherein the aim was to locate the surround and then subsequently take all steps necessary to fit the bathtub therewithin.
It is a still further object of the present invention to provide novel means for securing the bathtub to the adjacent building structural components, as well as to the surround; which permit of facile mutual adjustability to assure of appropriate alignment both for operative effectiveness and pleasing appearance.
It is another object of the present invention to provide a bathtub and alcove construction wherein the constituents are fabricated of durable materials, yet sufficiently light in weight so that the installation does not require developed skill on the part of the particular assembler and, thus renders the same amenable to economic, high speed installation without peril of undesired imperfections.
It is still another object of th present invention to provide a bathtub and alcove construction of the type stated wherein novel means are provided for rigidifying the bathtub against shifting during usage.
It is another object of the present invention to provide a bathtub and alcove construction composed of a plurality of durably constructed components which are especially designed for facile interconnection; which are economic in production as well as installation; and which components coact to provide a bathtub and alcove construction of singular reliability and durability in usage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a bathtub and alcove construction constructed in accordance with and embodying the present invention.
FIG. 2 is a transverse sectional view taken on the line 2--2 of FIG. 1.
FIG. 3 is a vertical transverse sectional view taken on the line 3--3 of FIG. 1.
FIG. 4 is a vertical view, in partial section, taken on the line 4--4 of FIG. 3.
FIG. 5 is a vertical transverse sectional view taken on the line 5--5 of FIG. 1.
FIG. 6 is a vertical view taken on the line 6--6 of FIG. 5.
FIG. 7 is a fragmentary horizontal plan view taken on the line 7--7 of FIG. 1.
FIG. 8 is a vertical transverse sectional view taken on the line 8--8 of FIG. 1.
FIG. 9 is a vertical transverse sectional view taken on the line 9--9 of FIG. 8.
FIG. 10 is a vertical transverse sectional view taken on the line 10--10 of FIG. 8.
FIG. 11 is a bottom plan view, in perspective, of a bathtub constructed in accordance with and embodying the present invention, illustrating the apron braces in engaged condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now by reference characters to the drawings which illustrate the preferred embodiment of the present invention, A indicates an integrated bathtub and alcove construction comprising a bathtub B and a surround C, comprehending a back panel 1 and a pair of corresponding side panels 2,2'. Tub B and the components of surround C are preferably constructed of fiberglass or the like, being thus of relatively lightweight, water impervious, and extremely durable, tough material, which is expectedly amenable to molding.
For purposes of illustration, bathtub B and surround C are shown as being receivingly disposed within a stud pocket P which comprehends the usual upper and lower horizontals h with a plurality of interconnecting, vertically extending, studs such as of conventional "2×4" character, located on predetermined centers; the vertical studs defining the rear of pocket P being identified 3, whereas the like studs located at the opposite ends of pocket P are designated 4,4'. It is, of course, understood that the combination bathtub and surround could be unitarily installed against a masonry wall, but it is believed that reference to stud pocket P will be adequately revelatory for disclosure purposes. Furthermore, bathtub B may be installed over any desired surface during any stage of construction, but when the combined bathtub and surround are installed within stud pocket P, it is desirable that the same be unitarily located prior to wall finishing.
It will be understood that pocket P is of conventional construction and does not form a part of the present invention but is environmental in nature to illustrate the typical room recess provided for the intended reception.
Bathtub B comprises a rear wall 5, a front wall 6, and end walls 7,7' for disposition of the latter proximate surround panels 2,2', respectively; and a bottom wall b. Said bathtub walls incline slightly inwardly and downwardly in conformity to normal molding practice; and the upper edges of rear wall 5 and end walls 7,7' are continuous with an outwardly extending horizontal flange or ledge 8. The outer edge of the portion of flange 8 projecting from front wall 6 is continuous with the upper edge of a downwardly projecting front apron 9 having a length in excess of bathtub B and bridges the distance between surround side panels 2,2' for presenting a finished appearance as well as a protective, structurally rigidifying expedient. The inner edge portion of flange 8 is integral with an upstanding flange 10, as may be in the order of 11/2"; the vertical axis of which is perpendicular to the plane of flange 8 (see FIGS. 3 and 5). It will be seen that flange 10 includes at the lower end thereof, as at 11, a short extension 10' projecting slightly below flange 8, and having its terminus preferably roundedly contoured, as at 12, for purposes presently appearing.
Provided for spacedly selected disposition upon the back portion of flange 10 is a plurality of tub clips 13, which may be of any predetermined number, but in actual practice it has been found that with a bathtub having an overall length in the range of 6', four such clips have proved adequate.
With reference to FIGS. 3 and 4 it will be seen that each bathtub clip 13 comprises a flat, rectangular body 13'; formed of rigid metal plate stock, and having the lower extremity thereof formed, as at 14, arcuately for complementarily gripping the rounded terminus 12 of flange 10 in which state body 13' is located against the rearwardly directed face of flange 10. Upwardly spaced from lower end edge 11, each bathtub clip 13 is substantially centrally punched to effect the development of a forwardly and downwardly projecting finger 15, for embracing the upper edge of flange 10, whereby finger 15 and the lower contoured end 12 of clip 13 may securely be graspingly mounted upon flange 10, while permitting sufficiently limited play so each clip 13 can be shifted longitudinally with respect to flange 10 for alignment with a preselected stud 3. In its portion upwardly of the related finger 15, body 13' of each bathtub clip 13 is provided with a plurality of apertures, as indiciated generally at 16, whereby fasteners 17, such as nails, screws or the like, of suitable extent and strength, may be projected therethrough to effect snug securement of the related clip 13 with the proximate stud 3, thereby tying bathtub B to the structural recess or stud pocket P.
As shown in FIG. 2, two bathtub clips 13 are preferably engaged to studs 3 between the ends of bathtub B, while two other bathtub clips 13 are engaged to end studs, as indicated at 3', respectively, substantially aligned with the ends of bathtub B. Thus, it will be seen that bathtub clips 13 serve to promote the snug and reliable anchorage of bathtub B to the rear portion of stud pocket P with stability in position being assured. As pointed out, bathtub clips 13 are adapted for relative movement along the rearward portion of upstanding flange 10 so that the dispersion of securement of bathtub B to the appropriate studs 3,3' is attained.
Also mounted for disposition upon the rearward portion of flange 10 is a plurality of wall clips w. In actual practice, since clips w will be disposed between the particular adjacent studs 3 the same should desirably be located upon flange 10 prior to mounting of bathtub clips 13.
With reference now being made to FIGS. 5 and 6, it will be seen that each wall clip w also contains a flat, generally rectangular body t, formed as of metal, and having a lower end edge portion 18 contoured, as at c, for complementarily accepting the lower rounded end 12 of flange 10. Substantially intermediate the lower and upper ends of each clip w the same is provided with a forwardly punched out finger 19 for gripping the upper edge of flange 10 so that by means of finger 19 and lower rounded end 18 wall clips w are reliably secured upon flange 10 but, yet, with there being such limited clearance as to allow the same to be moved longitudinally of flange 10 for requisite positioning. The upper ends 20, spacedly above fingers 19, each wall clip w is bent for inclination forwardly and upwardly, at a predetermined angle of less than 90°; being thus configured for reception within a retainer channel 21 provided at the upper end of a plate 22 fixedly carried upon the rear face of surround back wall 1.
With reference being now made particularly to FIGS. 5, 6 and 2, it will be seen that each plate 22 is suitably mounted upon back panel 1 in spaced relationship to the rear face thereof by means of pairs of vertically aligned, longitudinally spaced upper and lower bosses 23,23' and 24,24' integral with panel 1 and extending rearwardly therefrom. Each lower boss 24,24' is internally threaded (not shown) to engage screws 25 by which the related plate 22 is rigidly secured in position and with the related upper bosses 23,23' serving as spacers to inhibit any tendency of the associated plate 22 to bend toward panel 1. It will thus be seen that two such plates 22 are adequate for effecting securement of back panel 1 in proper relationship to bathtub B; said clips w being of such length as to be presented between adjacent studs 3 and hence non-interferring with bathtub clips 13. By virtue of the pairs of bosses 23,23', 24,24' a marked distance between the planes of back panel 1 and flange 10 is created so that the lower end of back panel 1, below said bosses, is rearwardly and downwardly inclined, as at 26, for abutment of its bottom edge 26' against back flange 10 to create an artistic, finished appearance to the line of jointure between bathtub B and surround panel 1.
For reasons to be discussed hereinbelow, bathtub clips 13 and wall clips w may be similarly utilized in conjunction with side panels 2,2', flange 10, and studs 4,4', but are not illustrated in order to avoid obvious repetition.
With particular reference to FIGS. 2, 8 and 9, it will be seen that back panel 1, at the upper end portion thereof, is turned rearwardly toward studs 3 of stud pocket P to define a co-extensive horizontal surface 27 which latter is integral with an upwardly projecting vertical flange 28 for flatwise abutment against studs 3. Flange 28 may be used as a nailing flange for extension therethrough, and into the adjacent studs 3, of preferably large head roofing nails for perfecting the securement of back panel 1 in position.
At each of the ends thereof, back panel 1 is provided with a short, forwardly directed corner-developing portion 29,29', the upper ends of which are continuous with surface 27 of panel 1 and with each of corner portions 29,29' containing a forwardly opening narrow groove 30 in the portion thereof proximate the adjacent end studs 4,4', as the case may be. Each groove 30 is open through the upper and lower ends thereof and is dimensioned for snugly receiving a tongue-forming flange 31 provided on the inner end of the adjacent side panel 2,2', as the case may be. With reference to FIG. 2, it will be seen that each side panel 2,2' is, with exception of flange 31, of similar configuration as back panel 1 so that the outer face of each side panel 2,2' will be continuous with the outer face of back panel 1. The upper end of each side panel 2,2' is provided with a horizontal surface 32 continuous with surface 27 of back panel 1 for pleasing symmetry and balance. The inner end of surface 32 is continuous with an upstanding coextensive nailing flange 33 for tight abutment against the confronting face of studs 4,4'. Flanges 33 thus serve for direct securement, as by large head roofing nails, within stud pocket P for enhancing the anchoring of surround panels 2,2'. It will be seen that flange 33 does not project above tongue-forming flange 31 so that when the latter is engaged panel flanges 28 and 33 will abut edgewise to provide an appearance of unbroken continuity.
For further increasing the rigidity of the surround portion of the bathtub and alcove construction, a suitable adhesive, such as, for example only, a silicon adhesive, may be applied within each groove 30 for enhancing securement of the received flange 31.
Manifestly, one of the side panels, such as 2, must be fitted with the requisite openings for the customary bathtub hardware, such as, shower heads, faucets and the like, so that the same may be suitably secured into operative position upon installation of surround panels, 1, 2, 2'.
From the foregoing it will be seen that the development of the bathtub and alcove construction of the present invention is readily apparent. Understandably, stud pocket P has been preliminarily constructed to the requisite measurements and with all supply lines to valves, tub spout and shower riser having been previously located. Trial fitting of bathtub B within stud pocket P to be certain that the same is level should be effected, as it may be necessary to shim under the tub for maximum overall floor contact.
Tub clips 13 are then snapped onto bathtub flange 10, as described above, and shifted slidingly lengthwise of flange 10 for facile disposition proximate the associated stud 3, (FIG. 2). In FIG. 4, clips 13 are shown with two of the same positioned at the ends of back panel 1 and two therebetween. Thus, for the average bathtub B, four such clips 13 are adequate, although, if desired, an additional number may be used, depending upon the number of studs 3 forming the rear portion of stud pocket P. Accordingly, tub clips 13 reliably maintain bathtub B in proper disposition within pocket P and with end walls 7,7' of bathtub B in abutment against studs 4,4', respectively, at the opposite ends of stud pocket P.
Thereupon, wall clips w are embracingly engaged upon bathtub flange 10 so as to be disposed between proximate studs 3 and thereby avoid any interference with clips 13. Two such wall clips w are shown in FIG. 2 as utilized with back panel 1. By reason of the length of wall clips w relative to the spacing between adjacent studs 3 the same will necessarily have negligible slideability so that the positioning of back panel 1 is all the more secure. Then back panel 1 is appropriately positioned with retainer channels 21 receiving the upwardly inclined upper ends 20 of the related wall clip w (see FIG. 5). Back panel 1 may thus be shifted relative to clips 13 by virtue of the relative slideability of retainer channels 21 and tub clip upper ends 20 to assure accurate positioning of back panel 1, with the end corner portions 29,29' received snugly in corresponding corners, as at 34,34', respectively, provided by end stud 3 and the proximate end panel stud 4,4', as the case may be. Then, as indicated above, back panel flange 28 may be nailingly affixed to the abutting studs 3 for stable permanent disposition of panel 1.
Before mounting end panels 2,2', the user may apply a suitable adhesive throughout the length of each groove 30 and then insert therein the selected tongue-like flange 31 thereby integrating the panels 1,2,2' of the now formed alcove into a unitary, attractive surround; it being understood that tub clips 13 and walls clips w would function in the same manner as with respect to back panel 1. Flanges 33 of end panels 2,2' are then secured to the adjacent studs 4,4', as by nailing, all as discussed hereinabove.
Referring now to FIG. 11, a particular feature for enhancing the rigidity of bathtub B will now be described. The base 35 of tub B is molded so as to present a substantially non-yielding, heavy ribbed design. Provided for spanning the distance between the lower end of apron 9 and front wall 6 is a plurality of braces 36 which are illustrated as being three in number, although there may be others if desired. Each brace 36 is of rigid, elongated character and the normally outer end 37 of each is pivotally secured, as by means of a rivet or pin 38 to a bottom inturned flange 39 formed at the lower end of apron 9. The inner end 37' of each brace 36 contains an aperture 40 dimensioned for snugly receiving a pin 41 integral upon base 35 of bathtub B. Each pin 41 is of such cross-section with respect to the associated aperture 40 to assure of a jam fit which is facilitated by the slightly yieldable character of the material of construction of each pin 41 so that such may be forced through the related aperture 40.
Thus, in shipping, and prior to installation, each brace 36 may be compactly disposed lengthwise of apron flange 39 and then immediately before positioning bathtub B the same may be swung into appropriate position and interengagement between pins 41 and apertures 40 effected. It is quite apparent that braces 36 serve to provide a markedly rigidifying expedient for bathtub B; inhibiting any relative movement between the same and apron 9 whereby any inadvertent impact upon apron 9 during usage will not promote any dislocation of bathtub B. The use of braces 36 thereby conduce to the economic production of bathtub B from lightweight, economic materials of construction, foremost among which is fiberglass.
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For use with a building interior recess construction, such as, a stud pocket, a bathtub and alcove construction wherein there is provided a bathtub, and a back panel and a pair of side panels comprising a surround for said bathtub. First clip members are provided for fixedly engaging the bathtub to adjacent portions of the recess construction; and with there being second clip members also engaging said bathtub for cooperating with retainer elements carried on the back panel to assure of appropriate disposition of the developed surround with respect to the bathtub. The back panel contains at opposite ends forwardly directed, relatively shallow corner portions, each of which is provided with a vertically extending groove. Each side panel along one edge portion is provided with a tongue-like flange dimensioned for reliable and snug reception with the adjacent groove of the back panel. Brace elements are also provided for rigidifying the connection between the bathtub and a front apron integrally formed therewith.
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This is a continuation-in-part of application Ser. No. 09/133,995 filed Aug. 14, 1998, now U.S. Pat. No. 6,110,404.
FIELD OF THE INVENTION
The present invention is directed to a method of extruding thermoplastic elastomer foam using water as a blowing agent. More particularly, the present invention is directed to a method for extruding thermoplastic elastomer foam in which the water and the thermoplastic elastomer are introduced to an extruder simultaneously.
BACKGROUND OF THE INVENTION
It is known to use water as a mechanical blowing agent in the extrusion of thermoplastic elastomer foam, and particularly the extrusion of such structures. Water is a desirable blowing agent, at least in part because it is non-toxic. Known methods of water blowing thermoplastic elastomers typically introduce the water to the thermoplastic elastomer after the thermoplastic elastomer has melted. Experience with extruding thermoplastic elastomer foam using water as a blowing agent has shown that certain extrusion profiles can be extruded at a rate of 40 to 80 feet per minute.
It is known how to produce low density foams from thermoplastic elastomers using water as a blowing agent which have certain compression or deflection rates, and compression set values, and low water absorption characteristics. However, simpler methods, not requiring the post-melt introduction of water, are sought.
It is desired to have a process for forming thermoplastic elastomer foam with water as a blowing agent suitable for use at increased extrusion speeds.
It is also desired to have a process for foaming thermoplastic elastomer foam which provides better control of the cell structure and the skin characteristics.
It is also desired to have a process for forming thermoplastic elastomer foam in which the water is introduced to the extruder simultaneous with the thermoplastic elastomer.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a method for extruding foam of a thermoplastic elastomer, which is a blend of olefin rubber and polyolefin resin, includes the steps of mixing the thermoplastic elastomer with water, introducing the mix to an extruder, melting and compressing the thermoplastic elastomer and water and extruding the resultant mix as foam. In more detail, a first quantity of thermoplastic elastomer in pellet form is mixed with a second quantity of water. The thermoplastic elastomer is allowed to soak for a predetermined period of time after mixing. After soaking, the mixed water and thermoplastic is introduced to an extruder. The thermoplastic elastomer is melted and mixed with the water to a uniform mix of thermoplastic elastomer and water. The mix is extruded through a die, wherein the water expands in a vapor form to create foam cells with the cells having walls of the thermoplastic elastomer.
According to another aspect of the invention, a method for extruding foam of a thermoplastic elastomer, which is a blend of olefin rubber and polyolefin resin, includes the steps of exposing the thermoplastic elastomer to steam, introducing the thermoplastic elastomer having the retained water to an extruder, melting and compressing the thermoplastic elastomer mixing it with the retained water and extruding the resultant mix as foam. As the mix is extruded through the die, the water expands in a vapor form to create foam cells with the cells having walls of the thermoplastic elastomer.
The inventive process enables the use of water as a blowing agent at increased extrusion speeds.
The inventive process enables better control of the cell structure and the skin characteristics.
The inventive process also enables the forming of thermoplastic elastomer foam in which water is introduced as a blowing agent to the extruder simultaneous with the introduction of the thermoplastic elastomer to the extruder.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a tub receiving thermoplastic elastomer.
FIG. 2 is a perspective view of the tub of FIG. 1 receiving water.
FIG. 3 is a perspective view of the tub of FIG. 2 showing a mixing operation.
FIG. 4 is a perspective view of the tub of FIG. 3 in a sealed condition.
FIG. 5 is a schematic representation of an extrusion system.
FIG. 6 is a schematic representation of the extruder of FIG. 5 .
FIG. 7 is a partial cutaway view of a steaming pot, together with a lid and a heating element.
FIG. 8 is a perspective view of a plastic bag receiving thermoplastic elastomer.
FIG. 9 is a perspective view of the plastic bag of FIG. 8 in a sealed condition.
FIG. 10 is a schematic representation of an extrusion system being manually fed thermoplastic elastomer.
FIG. 11 is a schematic representation of an extrusion system extruding foam.
DETAILED DESCRIPTION
The inventive process or method includes the following steps. Selecting a thermoplastic elastomer. Selecting an extruding device. Mixing the water with the thermoplastic elastomer. Feeding the hydrated thermoplastic elastomer into the extruder. Adjusting the speed, the temperatures and the pressure of the extruding device as required. Synchronizing the speed of the cooling conveyor with the speed of the foam exiting the extruder. Each of the steps will now be discussed in more detail.
With regard to the selection of a thermoplastic elastomer, the inventive process was developed for use with a thermoplastic elastomer of the type marketed under the name Santoprene® by Advanced Elastomer Systems, L. P. of Akron, Ohio. U.S. Pat. No. 4,130,535, which is hereby incorporated by reference, describes a thermoplastic elastomer well suited for use in the inventive method. The thermoplastic elastomer is described as a thermoplastic vulcanizate, comprising blends of olefin rubber and thermoplastic olefin resin in which the rubber is completely cured. Even though the rubber is fully cured, the blends are nevertheless processable as a thermoplastic material. Similar compounds are described in U.S. Pat. No. 4,311,628 which is also incorporated herein by reference.
Santoprene® is available in a wide range of hardness. Santoprene® is also available in both black and in neutral (colorable) form. The grades of Santoprene® used in the development of the inventive process were on the Shore A durometer scale. Santoprene® having a Shore A durometer rating or hardness of 73 was successfully used in testing of the inventive method. It should be appreciated, however, that even though testing was limited to relatively soft grades of material, the process is tunable to making foam from material ranging from Shore A 55 to Shore D 50 if desired.
With regard to mixing the thermoplastic elastomer and water, two methods are discussed herein: first, mixing thermoplastic elastomer and water with the water in liquid form; second, mixing thermoplastic elastomer and water with the water in a gaseous form, or as steam.
Mixing with water in its liquid form is discussed first. Predetermined quantities of thermoplastic elastomer and water are measured out and mixed. During testing, 500 pounds of thermoplastic elastomer pellets 10 were measured out into a large container or tub 12 as shown in FIG. 1 and combined with 8% by weight, or 40 pounds, of water 14 as shown in FIG. 2 . However, alternative mixing methods, including continuous mixing of pellets and water are possible alternatives. Pellets 10 and water 14 are folded over using a shovel 16 as shown in FIG. 5 . After mixing, the tub 12 is sealed with plastic wrap 18 or some other suitable mechanism, with some air remaining at the top of tub 12 . The pellets are allowed to soak for a period of 24 hours. After 24 hours, tub 12 is unsealed and the pellets and water are again mixed, being folded over with shovel 16 so that very little standing water remains in tub 12 . The wet pellets are then drawn from tub 12 and fed into a first end 20 of an extruder 22 by a vacuum type device 24 . Some water is lost from extruder 22 , escaping past seals at first end 20 of the extruder. It was noted that increasing the percent by weight of water combined with the pellets increased the amount of water escaping past the seals of the extruder, but did not substantially change the characteristics of the foam extruded. Decreasing the amount of water to a much lower level, such as 2%, appeared to have a deleterious effect on the characteristics of the foam extruded.
Some tests were also run with 2.5% by weight of mica added to the mix as a nucleating agent.
Other tests where run with gas producing chemicals or chemical blowing agents being added to the water and pellet mix. The chemicals can be added in powder or pellet form and are supplied in polypropelene carriers. The gas producing chemicals have been of both the endothermic type and the exothermic type. Both types of chemicals are available from the Boehringer Ingelheim Chemical Company, Specialty Products Division. Hydrocerol is the name under which the endothermic chemicals are sold. Some foam samples were made with exothermic additive, others with endothermic additives and yet others with both endothermic and exothermic additives. The addition appeared to provide a finer cell structure.
Also, it would be possible to introduce a pressurized gas as a blowing agent to the water and thermoplastic elastomer within the extruder, preferably after the thermoplastic elastomer has melted. Extruder 22 is a single screw extruder having a barrel length to diameter ratio of approximately 30:1, and compresses and melts the thermoplastic elastomer. Extruder 22 receives material at the first end 20 . Extruded foam 26 passes through a die 28 at a second end 30 of extruder 22 . Die 28 helps control the cross sectional shape of the extruded foam 26 . A screen pack 32 is placed at second end 30 extruder just before die 28 and serves to both filter the extruded material and to raise the pressure within the extruder adjacent to die 28 . The combination of screens and the precise mesh sizes chosen for use in screen pack 32 can be varied to alter the pressure in front of die 28 as required. The temperature within extruder 22 and the rotational speed of the extruder screw (not shown) can also be varied to control flow rate and pressure. The pressure of the die can vary from 250 psi to 2500 psi depending on the shape and cross sectional area of the die. The speed at which foam leaves the extruder is largely a function of the pressure at the die. Pressure and screw speed are varied as required to control the dimensions of the extruded foam and the cell structure and skin characteristics, including the skin thickness, of the foam.
The extruder screw is preferably operated at 10 to 25 rpm for many of the foams made. However, foam can be formed at screw speeds varying anywhere from at least 1 to at least 60 rpm.
The extruder is divided into six temperature zones. The first temperature zone 34 is where the mix of water and thermoplastic enters the extruder. Temperature zones 36 , 38 , 40 , 42 and 44 are between zone 34 and second end 30 . Each temperature zone has independent heating and cooling devices for varying the temperature within each zone as desired. Cooling is commonly provided by water or air or oil flow while heat is provided by electro-resistive devices or oil flow. Exemplary temperatures are provided in the example cited below. The temperatures of a gate area between die 28 and second end 32 is also controlled by a heating mechanism. Because there is typically no need to cool die 28 , a cooling mechanism was not used, although should one be desired, one could be integrated into die 28 .
The objective of controlling the melt temperature at the point of extrusion is to obtain a melt temperature near die 28 low enough to get good strength but not so low that the melt has difficulty passing through screen 32 and die 28 . Heating die 28 melts the extrusion at its outermost surface, providing a smooth skin over the extrusion for protection against water intrusion and wear. Pressure of the melted thermoplastic elastomer proximate to die 28 is adjusted to an optimal level. The rate in units of length per units of time of material which can be extruded from the second end of the extruder is a function of many factors including the rotational speed of the screw and the cross sectional area of the die. It is necessary to synchronize the speed of a take-off conveyer 34 which receives the extruded foam 26 to the speed of the foam 26 leaving the extruder 22 . The take-off conveyer 34 is used to cool foam 26 and is run at speeds from approximately 100 to 200 feet per minute, depending on the precise characteristics of the profile being extruded. This is a substantial improvement over the rate of 40 to 80 feet per minute for the prior art processes. Extrusion at yet higher rates of speed is possible, but was not done because of equipment limitations.
It has been determined that if water content is over approximately 6% by weight of the thermoplastic elastomer, some of the water will drain from the extruder if the extruder is not watertight. It becomes undesirable to use a watertight extruder as water content increases beyond 6%. When water content reaches approximately about 8% by weight, and a watertight extruder is employed, the extrusion process becomes unstable and the ability to control the process is lost.
The following is an exemplary use of the above described method. Five hundred pounds of Santoprene® material having a Shore A hardness of 73 is mixed with 40 pounds (8% by weight) of water in tube 12 . The water 14 and pellets 10 are folded over with shovel 16 . Tub 12 is sealed. After a 24 hour soak, pellet 10 and water 14 are again mixed. The mixture, at 73 degrees Fahrenheit, is fed into extruder 22 . Screen pack 32 includes a breaker plate with one course screen. The extruder temperature zones are maintained at the following temperatures:
Temperature
(Degrees
Zone
Fahrenheit)
1
200
2
210
3
330
4
380
5
380
6
380
Gate
385
Die
420
The extruder's screw is rotated at 35 rpm. The extruded foam 26 leaves extruder 22 at a rate of 195 feet per minute. The pressure proximate to the die is 625 psi. The resultant profile of the foam is approximately ¼″ by ⅜″. A 1″ length specimen of the extruded profile was, after cooling, loaded to achieve a 50% deflection. Approximately 1.52 pounds of force was needed to compress the 1″ length specimen from 0.256″ to approximately 0.128″.
Mixing thermoplastic elastomer and water with the water in a vapor form is now discussed.
The thermoplastic elastomer is mixed with water in vapor form by exposing pellets 10 to steam. For the purpose of development testing and evaluation, the mixing was done in a batch processing fashion, which is described below. However, it is anticipated that in production it will be beneficial to use a continuous flow process to steam the thermoplastic elastomer. Pellets 10 could be passed through a steam chamber (not shown) and then fed to an extruder.
To steam the thermoplastic elastomer, a large steaming pot 46 , as might be used for pressure cooking and shown in FIG. 7, is filled with water to a height H of approximately 6 inches. A cylindrical support ring 48 is centered in the bottom of pot 46 . A first round perforated pan 50 having a fine mesh screen 52 disposed there over is placed on top of ring 48 . A second round perforated pan 50 having a fine mesh screen 52 disposed there over is placed over first perforated pan 50 and screen 52 . The plates 50 are of substantially the same outer diameter as an inner diameter of pot 46 so as to prevent pellets 10 from dropping into the water.
Pot 48 is placed over a heating element 54 . When the water reaches boiling temperature, and the liquid water is being converted to steam, pellets 10 are introduced to pot 46 . Sufficient pellets 10 are added to fill pot 46 . Pans 50 are held sufficiently high by ring 48 that none of pellets 10 are immersed in the boiling water. Pot 46 is then covered with a lid 56 and pot 46 monitored until steam begins to flow from a hole 58 in lid 56 . At the moment steam begins to flow from hole 58 , a timer is started. At the end of a predetermined period of time, ten minutes in one preferred embodiment of the invention, pellets 10 are removed and placed in a container 60 , such as a plastic bag 60 as shown in FIG. 8, and then sealed as shown in FIG. 9 . The size and precise character of container 60 may be varied with the quantity of pellets 10 . The next batch of pellets 10 are added to pot 46 , and the steaming process repeated until the desired quantity of pellets 10 is steamed. The temperature of the steam within pot 46 is varied by controlling the pressure within pot 46 .
In the course of testing, samples were prepared at several temperatures and pressures. Initial data indicates that, employing the above described method of steaming pellets 10 , steaming pellets at 212° F. and atmospheric pressure results in more water retention than steaming pellets 10 at 250° F. and correspondingly elevated pressure. It should be appreciated that the terms “water retention” and “retained water” as used herein includes both water absorbed and absorbed by pellets 10 .
Subsequent to steaming, but prior to introducing pellets 10 to extruder 22 , samples of pellets are tested for water content. A Max-50 Moisture Analyzer™ (not shown) is used to determine the amount of water retained by the selected pellets 10 . The Analyzer weighs the sample, subjects the sample to heat to drive out the retained water, reweighs the sample and compares the weight of the now dry sample to the original weight to arrive at a value for the percent of moisture of the original sample. A relatively small amount of material, only about seven grams, is required for such testing.
It has been determined that a preferred amount of retained water is in the range of 3% to 6.75%, and is preferably in the range of 4% to 5%.
It should be appreciated that with increased experience with batch processing or continuous flow processing, the need to check for the water content in pellets should be reduced and potentially eliminated once a preferred amount of water retention is decided upon. Instead, the variables which control the amount of water retained by pellets 10 would be closely monitored and controlled.
The steamed pellets 10 are suitable for making foam immediately after steaming. However, it was determined that allowing pellets 10 to soak or age in the sealed containers for approximately 24 hours or more had a beneficial effect on the foaming characteristics of the thermoplastic elastomer. Additional improvement was seen after 48 hours of aging, and slightly more improvement after two weeks of aging. When left in a sealed container, water in liquid form collects at the bottom of the container, so that the distribution of water throughout the container becomes uneven.
Foam having a specific gravity of 0.17 was formed from Santoprene® grade 201-73, having a Shore A hardness of 73 , in the following manner. First, the pellets 10 were steamed to achieve a retained water content of 4%. The pellets 10 , in this example, were aged for approximately 14 days before being employed. The hydrated or water retaining pellets were introduced to the extruder via a hopper 62 as shown in FIG. 10 . The entire contents of the container 60 , including any liquid water which may have collected at the bottom, were fed into hopper 62 .
The extruder zones in this exemplary embodiment were maintained at the following temperatures:
Temperature
(Degrees
Zone
Fahrenheit)
1
200
2
220
3
310
4
380
5
375
6
370
Gate
380
Die
480
The extruder's screw was rotated at 30 rpm. The extruded foam 26 left extruder 22 at a rate of 120 feet per minute as shown in FIG. 11 . The pressure proximate to die 28 was 500 psi. The resultant profile of the foam was D-shaped and approximately ¼ inch by ⅜ inch. A 1 inch length specimen of the extruded profile was, after cooling, loaded to achieve a 50% deflection. Approximately 1.70 pounds of force was needed to compress the 1 inch length specimen by 50%.
It is to be understood that the above detailed description and example are merely exemplary in nature. Many variations from the detailed description and the example are possible within the scope of the present invention. For example, materials of widely different durometers may be employed. Different mixing methods may be used to combine the water with the thermoplastic pellets. The amount of time that the pellets are allowed to soak or age may be varied or potentially even eliminated. Indeed, it may be possible to entirely eliminate the soaking period. Different amounts of water may be used. Different extruder lengths may be employed. Different screw speeds may be used in the extruder. Different feed rates may be employed. More or fewer temperature zones may be used on the extruder. The temperature within the different zones may be varied from those cited in the example. It is therefore to be understood that the scope of the invention is determined by the scope of the appended claims.
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A method for extruding foam of a thermoplastic elastomer, which is a blend of olefin rubber and polyolefin resin, includes the steps of mixing the thermoplastic with water, introducing the mix to an extruder, melting and compressing the thermoplastic elastomer and water and extruding the resultant mix as foam. In more detail, a first quantity of thermoplastic elastomer in pellet form is mixed with a second quantity of water. The mixed water and thermoplastic elastomer is introduced to an extruder. The thermoplastic elastomer is allowed to soak for a predetermined period of time after mixing. The thermoplastic elastomer is melted and mixed with the water to a uniform mix of thermoplastic elastomer and water. The mix is extruded through a die, wherein the water expands in a vapor form to create foam cells with the cells having walls of the thermoplastic elastomer.
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TECHNICAL FIELD
The technical field of the present invention is that of processes for manufacturing parts using diffusion bonding and superplastic forming methods.
The technical field of the invention also relates to the molds for implementing the processes for manufacturing the parts, such as those mentioned above.
PRIOR ART
Processes for manufacturing hollow parts using diffusion bonding and superplastic forming methods have formed the subject of many disclosures in the prior art.
For example, in the field of the aeronautical industry, methods are known for manufacturing hollow parts formed by metal sheets, which can be implemented so as to produce elements of the jet engine blade type or else elements of the fluid duct type for a turbomachine.
In general, these manufacturing methods comprise several separate steps carried out in succession.
Among these steps, the first consists in carrying out a diffusion bonding operation on a plurality of metal sheets. These metal sheets are superposed one on top of the other and brought into contact with a plane surface of a structure suitable for accommodating them. The assembly formed by the metal sheets is then subjected to a heat source and to an injection of pressurized gas so as to carry out the diffusion bonding and obtain a one-part assembly.
Once this operation has been completed, the assembly obtained must generally undergo a deformation so as to adopt a general shape relatively close to a final shape of a part to be produced. To do this, the assembly is brought into contact with a surface of a mold and then pressed against this surface using pressurized-gas injection means and a heat source, these two elements combined allowing the assembly to be deformed. The surface against which the assembly is pressed has a geometry approximately identical to a geometry of the assembly that it is desired to obtain after this deformation operation has been carried out.
The third and final step of these processes according to the prior art consists in inflating one or more internal cavities of the assembly, for the purpose of producing a part having at least one hollow portion. This operation is carried out using the known technique of superplastic forming, by injecting pressurized gas between the metal sheets of the assembly, while keeping this assembly at high temperature, in a mold, the geometry of an internal wall of which corresponds to the final external geometry of the part to be produced.
Because of the multiplicity of steps to be carried out, the cycle time for producing these parts is long, which generates time and cost constraints. In addition, this type of process requires substantial specific tooling, since three different molds are needed to carry out the steps of the process.
It should be noted that when the part to be produced does not a priori need to undergo the second deformation step, especially when this part has a relatively plane final external geometry, it is then possible to carry out the diffusion bonding step and the superplastic forming step in succession during a single heating operation.
However, this method can in no way be applied to parts of complex geometry, a step of deforming the assembly formed by the sheets bonded together then being necessary.
SUMMARY OF THE INVENTION
The object of the invention is therefore to present a process for manufacturing parts that include at least one internal cavity, said process using in particular the techniques of diffusion bonding and superplastic forming, this process remedying, among others, the abovementioned drawbacks.
The subject of the present invention is therefore to propose a process that considerably simplifies the implementation of the various steps, so as in particular to reduce the cycle time for producing the parts and the amount of components making up the tooling.
The object of the invention is also to provide a mold intended for manufacturing parts that include at least one internal cavity, this mold being furthermore able to be used for carrying out a process meeting the abovementioned object.
To do this, the subject of the invention is firstly a process for manufacturing parts that include at least one internal cavity, this process comprising, in succession, a diffusion bonding step in which at least two metal sheets are bonded together, a deformation step in which an assembly formed by said metal sheets bonded together is deformed, and an inflation step in which each of the internal cavities is inflated by superplastic forming. The process according to the invention is carried out using a mold making it possible, during a single heating operation performed on this mold, to carry out, in succession, the diffusion bonding step and the deformation step on at least one first part lying within a primary recessed portion of the mold, and to carry out the superplastic forming inflation step on at least one second part lying within a secondary recessed portion of the mold.
Advantageously, the process according to the invention leads to a reduction in the cycle time for manufacturing the parts in comparison with the times that would be needed to carry out an entire manufacturing cycle when implementing the processes of the prior art.
In addition, a single operation of heating the mold allows the three steps of the process to be carried out, the first two of which being carried out on at least a first part and the third on at least a second part. Thus, the manufacturing cost of the parts is reduced because of the considerable reduction in the number of furnace-charging operations to be performed.
In the process according to the invention, one advantage lies in the possibility of treating at least two parts simultaneously during a single operation of heating the mold used. This is because a first part is subjected in succession to the diffusion bonding step and then to the deformation step, while a second part undergoes the final, inflation step by superplastic forming.
By implementing the process in such a manner, the number of elements needed to make up the tooling is greatly reduced. A single suitable mold comprising several recessed portions is then required to carry out all the steps of the process according to the invention.
Preferably, for each first part, the diffusion bonding step is carried out by providing, inside the primary recessed portion of the mold, a first injection of pressurized gas that presses the metal sheets against a first plane surface of the primary recessed portion of the mold. Additionally, still in respect of each first part, the step of deforming the assembly formed by said metal sheets bonded together is carried out while purging the pressurized gas introduced into the primary recessed portion during the first injection of gas, and then while providing a second injection of pressurized gas, which presses the metal sheets bonded together against a second surface of the primary recessed portion of the mold.
Advantageously, the process uses a mold comprising a primary recessed portion having surfaces suitable for carrying out the first two steps of the process. Thus, a single recessed portion advantageously makes it possible to present two surfaces against which the metal sheets will be pressed so as to carry out two different operations.
Preferably, for each second part, the inflation step carried out on each of the internal cavities by superplastic forming is performed by providing a third injection of pressurized gas into each of the cavities, the inflation being carried out in such a way that a deformed assembly of at least two sheets bonded together conforms to an internal wall of the secondary recessed portion of the mold.
The single operation of heating the mold is advantageously carried out at a uniform temperature over the entire mold, this temperature preferably being close to about 920° C.
The subject of the invention is also a mold intended for manufacturing parts that include at least one internal cavity. This mold comprises at least one primary recessed portion and at least one secondary recessed portion, each primary recessed portion having a first surface and a second surface, the first surface being plane so as to allow diffusion bonding of at least two metal sheets when the latter are pressed against this first surface, the second surface allowing deformation of the assembly formed by the metal sheets bonded together when this assembly is pressed against this second surface. Moreover, each secondary recessed portion of the mold is capable of accommodating a deformed assembly of metal sheets bonded together and undergoing inflation by superplastic forming, said secondary recessed portion having an internal wall of geometry substantially identical to a final external geometry of a part to be produced.
Preferably, the mold furthermore includes a block comprising one of the first and second surfaces of a primary recessed portion. This block also partly includes an internal wall of a secondary recessed portion.
Advantageously, equalizing the pressure of the two recessed portions separated by a single block such as that described above makes it possible, inter alia, to reduce the bending stresses on this block. It is then conceivable for the mold, and in particular this block, to be lightened, which means that materials of lower strength, and consequently of lower cost, can be used.
Other advantages and features of the invention will become apparent in the following non-limiting description.
BRIEF DESCRIPTION OF THE DRAWINGS
This description will be given in conjunction with the appended drawings, in which:
FIG. 1 shows a schematic view of a mold in a preferred embodiment of the invention, when this mold accommodates, on the one hand, metal sheets undergoing diffusion bonding and, on the other hand, a deformed assembly of metal sheets bonded together that undergoes inflation by superplastic forming;
FIG. 2 shows a schematic view of a mold used for implementing a process according to a preferred embodiment of the invention, when the heating operation carried out on this mold has been completed;
FIG. 3 shows a schematic view of a mold according to another preferred embodiment of the invention, when this mold accommodates, on the one hand, metal sheets that undergo diffusion bonding and, on the other hand, a deformed assembly of metal sheets bonded together that undergoes inflation by superplastic forming.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2 , these show a mold 1 intended for manufacturing parts 2 that include at least one internal cavity 4 and preferably just one cavity.
To obtain such hollow parts 2 , the mold 1 according to the invention makes use of the known techniques of diffusion bonding and superplastic forming. This is because the mold 1 is used to implement a process for manufacturing parts with the aim of carrying out a diffusion bonding step on at least two metal sheets 14 , a deformation step carried out on an assembly formed by at least two metal sheets 14 bonded together and finally an inflation step by the superplastic forming of at least one internal cavity 4 of a deformed assembly comprising at least two metal sheets 14 bonded together.
The mold 1 has at least one primary recessed portion 6 and at least one secondary recessed portion 8 . Preferably, as may be seen in FIGS. 1 and 2 , the mold 1 has a single primary recessed portion 6 and a single secondary recessed portion 8 .
As regards the primary recessed portion 6 , this has two surfaces 10 , 12 facing each other. Of these surfaces, a first surface 10 is plane, the planarity of this first surface 10 being necessary in order to achieve diffusion bonding of metal sheets 14 that are positioned flat and bear on this first surface 10 . The number of metal sheets 14 is preferably two.
The primary recessed portion 6 also has a second surface 12 . This second surface 12 may include convex portions and/or concave portions, the object being that this second surface 12 has a geometry approximately similar to a geometry that it is desired to apply by deformation to an assembly comprising metal sheets 14 bonded together, before this assembly is subjected to an inflation operation by superplastic forming.
As regards the secondary recessed portion 8 , this is capable of accommodating a deformed assembly of metal sheets 14 bonded together. This secondary recessed portion 8 has an internal wall 16 of geometry approximately identical to a final external geometry of a part 2 to be produced. Thus, during an inflation operation carried out by superplastic forming of a deformed assembly of metal sheets 14 bonded together, this assembly deforms until it conforms to the internal wall 16 of the secondary recessed portion 8 so as to adopt a final external shape corresponding to the shape of a part 2 that it is desired to produce.
The mold 1 also cooperates with various elements allowing the abovementioned various operations to be carried out.
Firstly, the mold is subjected to a heating operation, the applied temperature of which is about 920° C. This temperature may of course be modified by a person skilled in the art, according to his assessment of the criteria, such as the volume of the mold 1 or else the precise composition of the materials making up the metal sheets 14 .
In addition, during a phase of manufacturing parts 2 , the mold 1 is also connected to various pressurized-gas injection means (not shown).
Thus, the mold 1 is capable of undergoing a first injection of pressurized gas into its primary recessed portion 6 so as to press the metal sheets 14 , positioned one on top of the other, against the plane first surface 10 of the primary recessed portion 6 (as shown by the arrow A in FIG. 1 ). Through the effect of the heating and the injection of pressurized gas applied, the metal sheets 14 then undergo diffusion bonding. What is thus obtained is an assembly consisting of a single part comprising a plurality of metal sheets 14 bonded together.
FIG. 2 shows the mold 1 is again capable of undergoing an injection of pressurized gas, and again inside this primary recessed portion 6 . Before this injection, the gas resulting from the first pressurized-gas injection is purged in order to be replaced with the gas coming from a second injection of pressurized gas. This action has the consequence of pressing and deforming the assembly formed by the metal sheets 14 bonded together, to give this assembly a shape approximately identical to the shape of the second surface 12 . The arrow B in FIG. 2 symbolizes the pressing of the metal sheets 14 against the second surface 12 .
In the secondary recessed portion 8 , a third injection of gas may be provided in order to achieve, using the applied heat, inflation by superplastic forming. The inflation by superplastic forming therefore makes it possible to develop the internal cavity 4 inside the secondary recessed part 8 . Thanks to this third injection, the deformed assembly of metal sheets 14 bonded together adopts an external geometry corresponding approximately to the geometry of the internal wall 16 of the secondary recessed portion 8 . The metal sheets 14 may then conform to the internal wall 16 of the secondary recessed portion 8 and give the assembly an external shape corresponding to the external shape of a part 2 that it is desired to produce. The arrows C that are visible in FIGS. 1 and 2 symbolize the pressing of the metal sheets 14 against the internal wall 16 of the secondary recessed portion 8 .
It may also be noted that, to perform the various injections of pressurized gas, it is possible to use an inert gas, preferably a gas of the argon type.
Again with reference to FIGS. 1 and 2 , in a preferred embodiment of the invention, the mold 1 includes a block 18 that separates the primary recessed portion 6 from the secondary recessed portion 8 .
This block 18 in fact includes one of the first 10 and second 12 surfaces of the primary recessed portion 6 and also partly includes the internal wall 16 of the secondary recessed portion 8 . In other words, this block 18 , forming an integral part of the mold 1 , has two surfaces, each of which is used to at least partly constitute the primary 6 and secondary 8 recessed portions.
Preferably, the mold 1 comprises an upper block 20 a , an intermediate block 18 and a lower block 22 . These three blocks are superposed one on top of the other, thus defining the primary recessed portion 6 and the secondary recessed portion 8 . This configuration of the mold 1 is particularly beneficial because of the simplicity of the design, but also because of the simplicity that it offers when this mold 1 is being handled. In addition, when the three blocks 18 , 20 a and 22 of the mold 1 are fastened together, for the purpose of undergoing a heating operation, the various injections of pressurized gas carried out equalize the pressures of the primary and secondary recessed portions 6 , 8 , thereby greatly reducing the bending stresses on the intermediate block 18 . The immediate consequence of such pressure balancing on either side of the intermediate block 18 is therefore the possibility of lightening the latter, thereby consequently reducing the cost of the mold 1 .
FIGS. 2 and 3 show that the primary recessed portion 6 lies above the secondary recessed portion 8 , these relative positions of one portion with respect to the other possibly being, for example, those adopted when the mold 1 undergoes a furnace operation.
In this situation, it will be possible, as an alternative, to provide for the plane first surface 10 to lie on the intermediate block 18 ( FIG. 2 ), or for this plane first surface 10 to lie on the upper block 20 b ( FIG. 3 ). These two possibilities therefore correspond to two different preferred embodiments of the mold according to the invention.
The invention also relates to a process for manufacturing parts 2 that include at least one internal cavity 4 . As will be recalled above, the process must perform three separate steps in order to result in a final part 2 . These steps include a diffusion bonding step carried out on at least two metal sheets 14 , a deformation step carried out on an assembly comprising at least two metal sheets 14 bonded together and finally an inflation step carried out by thermoplastic forming of at least one internal cavity 4 of a deformed assembly of at least two metal sheets 14 bonded together.
To implement this process, a mold 1 is used that is made to undergo a single heating operation, preferably at a temperature of about 920° C.
During this single operation of heating the mold 1 , the process according to the invention is able to treat several parts 2 a , 2 b at the same time, by making them undergo different steps depending on the recessed portion of the mold 1 in which they are found.
Preferably, the process treats two parts 2 a , 2 b simultaneously.
It should therefore be noted that there is a first part 2 a and a second part 2 b , the first part 2 a undergoing the successive operations of diffusion bonding and deformation in a primary recessed portion 6 , while the second part 2 b undergoes, during the same furnace treatment, an inflation operation by superplastic forming in a secondary recessed portion 8 .
There are therefore three operations carried out during the same heating of a single mold 1 , whereas the processes of the prior art consist of three separate and successive heating steps, using in addition three different molds.
As may be seen in FIG. 2 , at the end of each part manufacturing cycle, that is to say when the single operation of heating the mold 1 has been completed, what is obtained is a part 2 having a geometry approximately identical to the geometry of a final part to be produced, this part 2 lying in the secondary recessed portion 8 .
In addition, there is also a deformed assembly of metal sheets 14 bonded together lying in the primary recessed portion 6 , this assembly being intended, during a following heating cycle of the mold 1 , to be positioned in the secondary recessed portion 8 so as to undergo inflation of its internal cavity 4 by superplastic forming.
This process is particularly beneficial within the context of the production of hollow parts used in the aeronautical industry.
Of course, various modifications may be made by a person skilled in the art to the process and to the mold that have just been described solely by way of non-limiting examples.
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A method for producing parts including at least one internal cavity. In the method at least two metal sheets are diffusion bonded; then the bonded metal sheets are bent; and then each of internal cavities is inflated by superplastic forming. The method is carried out by a mold allowing at least one first part to be diffusion bonded and then bent while inflating at least one second part by superplastic forming during a single operation, whereby the mold is heated. The method can be applied, e.g., to the field of aeronautics.
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BACKGROUND OF THE INVENTION
[0001] Organizations and businesses of all sizes and missions, buy a diverse array of assets. In diversity, these can extend from computer equipment to cattle. Yet the control, movement, resources available and management of these assets, the ongoing costs to maintain them, their purpose and even where they are located is not obvious to many of their owners. In addition many organizations must comply to industry or government standards with respect to the maintenance of such assets which adds significantly to the “need to know” factors surrounding them. The reliance by organizations on these often high value assets is constant and growing. Yet the costs of securing, managing and maintaining assets are prohibitively expensive and often are not visible to key stakeholders. Decision making as a result occurs in a financial and needs analysis vacuum. The challenge is exacerbated by organizations being at breaking point in terms of budgetary, technology, physical space constraints and a shortage of staff. Due to a lack of transparency and visibility every asset has the potential of being used inefficiently, lost all together or even stolen. Today many organizations cannot find assets, tell you the value of them or their use or be able to see changes in their status. Yet countless hours are spent by employees trying to achieve these through basic applications, spreadsheets and in many cases manual processes. In today's world there are real question marks as to what value these assets are really delivering and much time is wasted in this pursuit. While technology has revolutionized almost every area of business life, technological advancement has paradoxically made it difficult to efficiently take control over these challenges.
[0002] There are numerous point based solutions that seek to address parts of the problem but there has not until now been a total solution that covers assets in multiple locations that can deliver critical information in the right form to multiple stakeholders. Point based systems are often very expensive, do not embrace the latest technologies and either can't integrate with other important systems organizations have or find doing so extremely difficult. Their mechanisms are often too cumbersome when seeking to manage assets day to day. It is also typically very tedious and manually intensive to maintain up-to-date information in these solutions.
SUMMARY
[0003] The present invention provides a system for semantically modeling relationships and dependencies between groups, enclosures, assets, and support entities according to an industry specific manner. An exemplary system includes a user interface device, a relational database, and a processor in data communication with the database and the user interface device. The processor receives relationship and dependency information between groups, enclosures, assets, and support entities for a corporation from the user interface device, receives attributes with associated measurements for the groups, enclosures, assets, and support entities for the corporation from the user interface device. The attributes with associated measurements are formatted according the specific industry of the corporation. The relationship and dependency information and the attributes are stored with associated measurements into the relational database.
[0004] In accordance with further aspects of the invention, the system includes a plurality of data transmission devices. Each of the plurality of data transmission devices associated with one of the groups, enclosures, assets, and support entities for the corporation. The plurality of data transmission devices include data of the associated one of the groups, enclosures, assets, and support entities. The system also includes a plurality of data collection devices in signal communication with the processor and the plurality of data transmission devices. The plurality of data collection devices retrieves the data from the plurality of data transmission devices. The data transmission devices and data collection devices include at least one of radio frequency identification (RFID) tags, antenna, readers or concentrators. The processor enters the data received from the data collection devices into the relational database.
[0005] In accordance with other aspects of the invention, the processor executes a plurality of data Application Program Interfaces (APIs) that integrate data received from the data collection devices into a comprehensive view of the groups, enclosures, assets, and support entities based on the relational database.
[0006] In accordance with still further aspects of the invention, the processor allows a user to create at least one of a graphical or text based report regarding one or more of the groups, enclosures, assets, and support entities. The report includes at least one of absolute values, ranges or comparative values of at least a portion of the attributes. The report filters, sorts, or orders the groups, enclosures, assets, and support entities.
[0007] In accordance with yet other aspects of the invention, the processor calculates return on investment based on the asset data. The asset data includes a cost to replace value or a cost of ownership value.
[0008] In accordance with still another aspect of the invention, the processor allows a user to define one or more perimeters within which each of the assets are located and to identify the assets within the one or more perimeters.
[0009] In accordance with still further aspects of the invention, the database includes a supplier database that stores all assets in an individual group and across all groups.
[0010] In accordance with yet another aspect of the invention, the system includes a remote access device that is in data communication with the processor via a public or private data network. The remote access device includes a mobile device, a laptop computer, a tablet computer or a desktop computer.
[0011] In accordance with further aspects of the invention, the processor generates a graphical user interface that provides a three dimensional (3D) visualization of the groups, enclosures, assets, and support entities.
[0012] In accordance with still further aspects of the invention, the processor allows a user to modify records of the assets, enclosures, groups, and support entities, display values of the attributes, and edit the values of the attributes within the relational database.
[0013] In accordance with additional aspects of the invention, the processor allows a user to semantically map the received attributes from disparate sources and the supplier database. The semantically mapped attributes provide context to the received attributes and the attributes' relation to assets, enclosures and groups.
[0014] In accordance with yet additional aspects of the invention, the processor allows a user to uniquely identify a location of an asset and physical orientation based on data received using at least one of a Radio Frequency Identification (RFID) system, a Real-time Locating System (RTLS) or Global Positioning System (GPS).
[0015] In accordance with still additional aspects of the invention, the processor allows a user to uniquely identify asset identifiers to associate, capture, monitor and timestamp, data with other data pertaining to the asset within the system.
[0016] In accordance with other additional aspects of the invention, the processor allows a user to share asset information comprising at least one of a physical asset component data, financial data, contractual data and utilization data and permit the management, display and analysis of asset information on a single user interface.
[0017] In accordance with still other aspects of the invention, the processor allows a user to perform at least one of a query, an interrogation, a forecast, a what if scenario and to perform modeling of return on investment based on any change to assets, enclosure and groups.
[0018] In accordance with further aspects of the invention, the processor provides trending information and analysis of the user's industry as compared to the user's specific asset deployments.
[0019] In accordance with still further aspects of the invention, the 3D visualization includes annotation of groups with at least one of bounds, extents, photographs and related media elements, wherein the 3D visualization comprises at least one of a diagrammatic image or a figurative image. The user interface allows a user to perform at least one of browse, find, create, update or delete information associated with the assets, the enclosures, the groups, and the support entities, and the relationship information. The processor can show via the graphical user interface changes to status of an asset. The processor generates a unique identifier based on a user defined asset search. The unique identifier provides a visual indication of the presence and location of all assets that match the user defined asset search. The processor allows a virtual walkthrough of the 3D visualization as presented on the display device based on user entered commands from the user input device. The processor displays asset attributes based on a user entered selection signal from the user input device during the virtual walkthrough.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings:
[0021] FIG. 1 is a block diagram showing a conventional computer system, various computer peripherals, and various communication means formed in accordance with an embodiment of the invention;
[0022] FIG. 1-1 is a topological view of the system and its components according to the embodiment of the current invention;
[0023] FIG. 2 is a logical, semantic view of the relationships between group, enclosure and asset entities and examples of such interrelations used by the system of FIG. 1 for capturing and managing assets in disparate locations, indoors, outdoors, locally or geographically dispersed according to an embodiment of the invention;
[0024] FIG. 2-1 shows a typical example of FIG. 2 as it relates to datacenters providing a logical, semantic view of the relationships between group, enclosure and asset entities within a datacenter environment.
[0025] FIG. 3 is a further schematic sample view of the system for capturing and managing datacenter assets in disparate locations and how other information from other data sources are semantically mapped to entities according to an embodiment of the invention;
[0026] FIG. 4 is a schematic view of the underlying four tier architecture of the system for capturing and managing assets in disparate locations and how that information is stored, managed and communicated according to an embodiment of the invention;
[0027] FIG. 5 shows a datacenter example of the topological schematic view of the system for capturing and managing inventoried and tagged assets in disparate locations and how that information once in the database is accessed by user and allows specific requirements to be achieved according to an embodiment of the invention; and
[0028] FIGS. 6 through 17 show illustrative embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one skilled in the art will understand that the invention may be practiced without these details or with various combinations of these details. In other instances, well-known systems and methods associated with, but not necessarily limited to, asset management and methods for operating the same may not be shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments of the invention.
[0030] An embodiment of the invention is deployed on or used in conjunction with, but is not limited to an internet based service and a browser. There are pluralities of components for managing critical assets, integrating all the critical information pertaining to the asset and delivering this information in the needed form for individual stakeholders. Stakeholders have the ability to spatially navigate to an assets location, for example in a building, a field, locally or across the globe, in 2 or 3 Dimensions from their desktop, even when they are hundreds or thousands of miles from the physical asset location. These components may include but are not limited to a desktop browser, mobile device applications, asset information repositories and API's; local or remote information synchronization and maintenance of information pertaining to assets and their interdependencies.
[0031] FIG. 1 is a diagram showing a conventional computer, various computer peripherals, and various communication means formed according to an embodiment of the invention. For purposes of brevity and clarity, embodiments of the invention may be described in the general context of computer-executable instructions, such as program application modules, objects, applications, models, or macros being executed by a computer, which may include but are not limited to personal computer systems, hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, mini computers, mainframe computers, and other equivalent computing and processing sub-systems and systems. Aspects of the invention may be practiced in distributed computing environments where tasks or modules are performed by remote processing devices linked through a communications network. Various program modules, data stores, repositories, models, federators, objects, and their equivalents may be located in both local and remote memory storage devices.
[0032] By way of example, a conventional personal computer, referred to herein as a computer 100 , includes a processing unit 102 , a system memory 104 , and a system bus 106 that couples various system components including the system memory to the processing unit. The computer 100 will at times be referred to in the singular herein, but this is not intended to limit the application of the invention to a single computer because, in typical embodiments, there will be more than one computer or other device involved. The processing unit 102 may be any logic processing unit, such as one or more central processing units (CPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. Unless described otherwise, the construction and operation of the various blocks shown in FIG. 1 are of conventional design. As a result, such blocks need not be described in further detail herein, as they will be understood by those skilled in the relevant art.
[0033] The system bus 106 can employ any known bus structures or architectures, including a memory bus with memory controller, a peripheral bus, and a local bus. The system memory 104 includes read-only memory (“ROM”) 108 and random access memory (“RAM”) 110 . A basic input/output system (“BIOS”) 112 , which can form part of the ROM 108 , contains basic routines that help transfer information between elements within the computer 100 , such as during start-up.
[0034] The computer 100 also includes a hard disk drive 114 for reading from and writing to a hard disk 116 , and an optical disk drive 118 and a magnetic disk drive 120 for reading from and writing to removable optical disks 122 and magnetic disks 124 , respectively. The optical disk 122 can be a CD-ROM, while the magnetic disk 124 can be a magnetic floppy disk or diskette. The hard disk drive 114 , optical disk drive 118 , and magnetic disk drive 120 communicate with the processing unit 102 via the bus 106 . The hard disk drive 114 , optical disk drive 118 , and magnetic disk drive 120 may include interfaces or controllers (not shown) coupled between such drives and the bus 106 , as is known by those skilled in the relevant art. The drives 114 , 118 , 120 , and their associated computer-readable media, provide nonvolatile storage of computer readable instructions, data structures, program modules, and other data for the computer 100 . Although the depicted computer 100 employs hard disk 116 , optical disk 122 , and magnetic disk 124 , those skilled in the relevant art will appreciate that other types of computer-readable media that can store data accessible by a computer may be employed, such as magnetic cassettes, flash memory cards, digital video disks (“DVD”), Bernoulli cartridges, RAMs, ROMs, smart cards, etc.
[0035] Program modules can be stored in the system memory 104 , such as an operating system 126 , one or more application programs 128 , other programs or modules 130 and program data 132 . The system memory 104 also includes a browser 134 for permitting the computer 100 to access and exchange data with sources such as web sites of the Internet, corporate intranets, or other networks as described below, as well as other server applications on server computers such as those further discussed below. The browser 134 in the depicted embodiment is markup language based, such as Hypertext Markup Language (HTML), Extensible Markup Language (XML) or Wireless Markup Language (WML), and operates with markup languages that use syntactically delimited characters added to the data of a document to represent the structure of the document. Although the depicted embodiment shows the computer 100 as a personal computer, in other embodiments, the computer is some other computer-related device such as a personal data assistant (PDA), a cell phone, or other mobile device.
[0036] The operating system 126 may be stored in the system memory 104 , as shown, while application programs 128 , other programs/modules 130 , program data 132 , and browser 134 can be stored on the hard disk 116 of the hard disk drive 114 , the optical disk 122 of the optical disk drive 118 , and/or the magnetic disk 124 of the magnetic disk drive 120 . A user can enter commands and information into the computer 100 through input devices such as a keyboard 136 and a pointing device such as a mouse 138 . Other input devices can include a microphone, joystick, game pad, scanner, etc. These and other input devices are connected to the processing unit 102 through an interface 140 such as a serial port interface that couples to the bus 106 , although other interfaces such as a parallel port, a game port, a wireless interface, or a universal serial bus (“USB”) can be used. A monitor 142 or other display device is coupled to the bus 106 via a video interface 144 , such as a video adapter. The computer 100 can include other output devices, such as speakers, printers, etc.
[0037] The computer 100 can operate in a networked environment using logical connections to one or more remote computers, such as a server computer 146 . The server computer 146 can be another personal computer, a server, another type of computer, or a collection of more than one computer communicatively linked together and typically includes many or all the elements described above for the computer 100 . The server computer 146 is logically connected to one or more of the computers 100 under any known method of permitting computers to communicate, such as through a local area network (“LAN”) 148 , or a wide area network (“WAN”) or the Internet 150 . Such networking environments are well known in wired and wireless enterprise-wide computer networks, intranets, extranets, and the Internet. Other embodiments include other types of communication networks, including telecommunications networks, cellular networks, paging networks, and other mobile networks. The server computer 146 may be configured to run server applications 147 .
[0038] When used in a LAN networking environment, the computer 100 is connected to the LAN 148 through an adapter or network interface 152 (communicatively linked to the bus 106 ). When used in a WAN networking environment, the computer 100 often includes a modem 154 or other device, such as the network interface 152 , for establishing communications over the WAN/Internet 150 . The modem 154 may be communicatively linked between the interface 140 and the WAN/Internet 150 . In a networked environment, program modules, application programs, or data, or portions thereof, can be stored in the server computer 146 . In the depicted embodiment, the computer 100 is communicatively linked to the server computer 146 through the LAN 148 or the WAN/Internet 150 with TCP/IP middle layer network protocols; however, other similar network protocol layers are used in other embodiments. Those skilled in the relevant art will readily recognize that the network connections are only some examples of establishing communication links between computers, and other links may be used, including wireless links.
[0039] The server computer 146 is further communicatively linked to a legacy host data system 156 typically through the LAN 148 or the WAN/Internet 150 or other networking configuration such as a direct asynchronous connection (not shown). Other embodiments may support the server computer 146 and the legacy host data system 156 on one computer system by operating all server applications and legacy host data system on the one computer system. The legacy host data system 156 may take the form of a mainframe computer. The legacy host data system 156 is configured to run host applications 158 , such as in system memory, and store host data 160 such as business related data.
[0040] A 3-Dimensional (3D) Visualization component provides a real-time 3D visualization, navigation and reporting of all assets both physically and virtually. The 3D Visualization component automates the monitoring, analysis and interrogation of assets to optimize every functional aspect. The 3D Visualization component is accessed though a powerful web graphical user interface (GUI) dashboard.
[0041] Using the 3D Visualization component a user can select an asset or assets that are of interest. The Asset Halo Glow Identifier maps and highlights all assets that match the specific asset search and allows the visual differentiation between selected and non-selected assets. Non-exhaustive lookup examples would include assets that are of a specific age, livestock of a particular breed, assets that are moving versus not moving and assets that need servicing, Once the visualization has highlighted where those assets are the user can virtually walk up to them. Once there, the user can click or mouse-over on the asset or series of assets and be shown detailed attribute information about the Asset and all its credentials based on the particular stakeholder view. This for example could be financial information about the Asset, when it was purchased, weight, consumption, and how much is it costing. As another example one may want to know details about the movement of an asset; where it has been over the past month and where it is now. Whatever view the stakeholder wishes, based on their role, can be satisfied by the 3D Visualization component.
[0042] A semantic database is a hub that centralizes and models all information and brings assets into a unified intelligent infrastructure. The database is a hosted database accessed through a powerful web GUI dashboard that allows customers to manage, analyze, report on and visualize assets, assets in buildings and/or outdoors and all the information pertaining to them. The database provides the business intelligence and knowledge based on which asset management, location management, capacity management and planning takes place. All existing asset information, their utilization, location, maintenance schedules and financial data is captured by the database. Each Organization, Enclosure, and Asset, and support entities having attributes with associated measures specific to their industry. By way of example:
a. A non-exhaustive example for an Asset modeling a computer would be weight, power, cooling, height, width, length b. A non-exhaustive example for an Asset modeling livestock would be weight, birth date, inoculations, breed and sex
[0045] The database allows customers to intuitively manage resource usage, forecast and introduce new capacity simply and quickly. Stakeholders from across an organization including asset owners, facility managers, administrators and finance can access the critical information they need from the database eliminating the cost and expense of having multiple sources and the errors that inevitably result.
[0046] The system integrates and semantically aligns information directly accessed from source providers of assets capturing all key specification data and automatically populating this information as entities within the database for existing and newly acquired assets. It further enables the same from any other valid source of information that allows a complete picture of an asset and all its attributes. Such information is downloaded and stored in the database. In doing so, additional entities can be added to model behaviors and relationships specific to each Industry.
a. In the IT industry for example, a Project entity can be created which tracks such things as project budget and name, and have relationships to the Organizations and Assets involved. b. In the livestock industry, a Contract entity could be added, which then has relationships to the animal involved in a given sales contract, specifies the price per head, and has relations to the Organizations representing the buyer and seller of the cattle.
[0049] The system allows users to undertake detailed analysis of assets based on all the multi-dimensional information provided. It provides comprehensive “what if” and “time machine” capabilities that allows users to model scenarios or see the status of an asset in a snapshot moment in time. One can further for example draw comparisons of existing assets with alternatives, challenge methods for asset optimization, use and deployment, and identify any costs to replace or extend their use.
[0050] The system captures and consolidates asset data pertaining to all customer using the system within an industry. The system then provides back to each customer consolidated trending information pertaining to the assets they collectively have. In doing so the system delivers industry insights to aid the decision making process and learnings from actual dynamics across an industry. Then by way of a single example a customers can review trends in swapping or replacing assets and run replacement scenarios on existing asset with new potential alternatives.
[0051] The system allows the definition and mapping of perimeter extents of an Enclosure through the Perimeter Interface Module. A non-exhaustive example of perimeter types by industry include a datacenter room, a barn, a freight container or a casino room. Assets are the able to be located and identified within the perimeter. The Perimeter Interface Module works with passive and active assets. The Perimeter Interface Module has been designed to be generic and does not require modification for different vertical markets such as Datacenter, Retail, Security, Livestock and Gaming, since it is independent of layered applications and databases that manages and collects asset information for statics output.
[0052] The system allows the unique identification of an Asset. Unique identifiers in a datacenter example would be an asset's serial number combined with the RFID Tag number and signal associated with that asset. The combination of these two attributes enables the system to associate, capture, monitor and timestamp data from other data sources that pertain to the Asset within the system and ensures its accuracy and integrity.
[0053] Through the use of advanced, low cost local Radio Frequency Identification (RFID), Real-time Locating Systems (RTLS) or Global Positioning System (GPS) tags and sensors, the present invention provides a real-time synchronized view between the system and the “real time location of assets geospatially”. Tags and sensors send information to “in-theater” readers, scanners and concentrators, that integrate to the Datacollector and sent via the network whether intranet or internet to the system. The system then monitors asset provisioning, movement and use thereby reducing and in some cases eliminating the need for human intervention in physical “in-theater” monitoring. It provides the ultimate in asset security and theft deterrence identifying an asset's status, immediately flagging all movements to key stakeholders.
[0054] A comprehensive asset and event management Application Program Interface (API) preferably includes a set of API's to support integration of information from disparate sources pertaining to each individual asset or group of assets. These API's support specifying products and the on-boarding of new assets, events and updates, detailed analysis whether historic, current or futuristic and establishing relationships between people and the assets in question and/or sharing information with colleagues or important 3rd parties. The ability to share information with other users/stakeholders delivers to each broad access to important data that would otherwise be unavailable or require users to manually intervene with disparate sources/applications to access the data. The system provides the automation and delivery of an information sharing paradigm through API's into unified Graphical User Interface. API's also provide the ability to obtain aggregate, statistical and individual reporting data, including, but not limited to the type, number, cost, location and usability information about assets.
[0055] Using RFID, RTLS or GPS readers, scanners and concentrators, an audit component identifies moves, additions or changes to an asset. Audit sensors and reader devices, integrated to the Datacollector and sent via the network whether an intranet or the internet to the system which receives downloaded information concerning the assets at a particular locations. The audit component then verifies that all of the assets have an active tag. If not, data entry is performed on new assets. The audit component then performs a tag scan and if an asset is missing, the audit component verifies and records the missing asset; if an asset is new (new, known tag), the audit component performs data entry.
[0056] The present invention has the ability to analyze and make decisions based on the integration of facts concerning every aspect of an asset and use of tools provided to support and validate such decisions.
[0057] All assets have logistical implications, cost to run or maintain, cost to replace, and benefits/implications of replacement. In particular it is important to know and plan what alternatives exist and the timing options for replacement. An embodiment of the system provides capabilities for assessing and planning these types of scenarios and provides the mechanisms to properly account for them.
[0058] Information about assets is made available through the system infrastructure, optionally using a GUI. This information may be available to users via standard reports or the “user defined” report building capability for the purposes of managing the effectiveness of assets including their cost to maintain, usability, security, viability end of life and replacement strategy. The system further provides a user defined alert capability that lets key users know when certain important events take place.
[0059] The systems provides the Smart Algorithms module that allows users to seamlessly automate the analysis, data mining, calculation and visualization of return on investment by comparing re-fresh scenarios between current Assets information including but not limited to cost to replace, cost of ownership, consumption, space allocation and performance with future alternatives.
[0060] FIG. 1-1 provides a topological map of the systems and its current components. It shows the inter-relationships between the components and embodiments of the invention.
[0061] FIG. 2 describes an embodiment of the invention in the underlying Omnibus technology architecture namely, a system capable of defining arbitrarily nestable and classifiable entities, which represent purely semantic relationships. There are three primary entity types:
[0062] 1. Groups: Logical groupings of other groups/enclosures i.e. Division, Company, etc such as “Organization” e.g. a company, a farm, a freight liner or a casino
[0063] 2. Enclosures: A Group with ‘extent’, and other attributes. A system capable of defining arbitrarily nestable and classifiable Enclosures, which include both a semantic label, and an extent, a position, and a physical orientation in space relative to its parent or some global coordinate system. Represent organizational units that have a physical presence of some kind These can be classified arbitrarily, “Server Room”, “Datacenter”, “Container”. They can be associated with users, projects or contracts. They can have other Enclosures or Assets as children. By way of example Enclosures:
Can be used to model a Datacenter, with an Enclosure root node labeled as “Building”, and given a extent modeling the building volume, and its position in latitude and longitude. This has sub-enclosures such as “Floor” and “Room”, each with its own size, and position relative to the parent using the Perimeter Mapping Module. Can be used to model any enclosures within any organization. In the case of a farm, enclosure examples include Field with sub-enclosure Barn with sub-enclosure Stall using the Perimeter Mapping Module. Can then be associated with any applicable Group that own(s) them.
[0067] 3. Assets: Physical items with physical presence, physical traits and measurable attributes (Weight, Temperature, Size, Age, Value) and can be classified arbitrarily, such as “Computer Server”, “Horse”, “Painting”. All Assets can contain sub-asset classes.
[0068] FIG. 2-1 describes an embodiment of the invention as it specifically relates to datacenters within the underlying Omnibus technology architecture where the system capable of defining arbitrarily nestable and classifiable entities such as locations, buildings, floors and machine rooms.
[0069] Furthermore, for each area of applicability, Application Specific Entities can be added with their own attributes, which are then associated with an enclosure that contains them.
Computer equipment as Asset entities can be associated with the Enclosure modeling a datacenter room Enclosure on a particular floor Enclosure. Horses as entities can be associated with the stall enclosure they are in and the higher level barn Enclosure.
[0072] FIG. 3 illustrates an embodiment of the invention that allows other objects, groups and their separate trees to be further added to model other special purpose objects, semantic groupings and their interrelationships to existing objects to model and manage the inter-relationships between Groups. These may be for example in a datacenter scenario:
A “Contract” object that can be used to denote the support relationship between a separate Organization providing maintenance services. Groups and Assets/Enclosures encapsulating a cross-department or multi-company project. A “Source” that is the originating organization of the asset facilitating the capture of specific information pertaining to an Asset.
[0076] In this embodiment, the Persistence/Data Tier, Business Services and Web Services tiers are implemented using the Java EE 6 platform which enables broad industry integration and inter-operability.
[0077] FIG. 4 is a schematic view of the underlying 4 Tier Omnibus Architecture developed as the underlying technology used for the system according to an embodiment of the invention.
[0078] A Persistence/Data Tier provides an abstraction layer with respect to how the data is stored. It deals with storage and retrieval of the data in a storage neutral manner. In the current embodiment, JPA 2.0, a part of the Java EE 6 framework, is utilized to manage storage and retrieval of data from various databases in a vendor neutral manner.
[0079] A Business Service Tier contains the application software and services. This tier is designed to be independent of the persistence/data tier so that applications can be built independent of the data storage technology and vice versa. The business logic tier handles enforcing security, validation of data, and enforcement of constraints so as to ensure a consistent model of the system being managed. The current embodiment uses a variety of Java EE6 services and features to provide these features, including Java CDI, EJB 3.1 and JAAS.
[0080] A Web Service Tier provides access to a variety of clients potentially using a variety of technologies, such as REST, Java RMI, and others. The current embodiment of this invention uses the JAX-RS technology supplied by Java EE 6 to provide a REST interface to the underlying services and data. The REST architectural style is widely used on the World Wide Web. Its architecture characterizes and constrains the macro-interactions of the four components of the Web, namely origin servers, gateways, proxies and clients, without imposing limitations on the individual participants. In this way, it provides simplified access to its services to a wide variety of clients. As business needs change, the current embodiment can easily be extended to support other service styles as well, such as JAX-WS, and Java RMI.
[0081] A Client Tier represents external and internal customers interacting with the current embodiment of this invention through a variety of client devices and applications. In the current embodiment of this invention, this is done through its REST based web services interface, but as stated above, the web service tier can be expanded to support clients that utilize different protocol technologies such as RMI.
[0082] FIG. 5 shows a datacenter example of the topological schematic view of the system for capturing and managing assets in disparate locations and how that information is translated into specific user requirements according to an embodiment of the invention. When “Active” RFID technology is deployed, sensor concentrators are deployed and run onsite at a customer location. The Sensor Concentrators capture asset information in real-time or near real-time information from RFID readers which in turn checks the heartbeat. The heartbeat includes a timer that fires, sending heartbeat messages and tag observations including asset temperature updates, reader updates showing motion when a tag moves from one reader to another, activator updates when motion forces the activation of a tag, usually when it moves through an activation field at a door. The Sensor Concentrators send all captured data through the gateway and across secure network, intranet or internet connections to the backend database. Once in the database users can observe what is happening at each location for each asset and manage their needs appropriately.
[0083] Defining Services for Asset Management and a Single Interface for Managing, Analyzing, Visualizing and Reporting
[0084] An embodiment of the invention provides a toolset for managing, analyzing, visualizing and reporting on assets in multiple, disparate locations in a single GUI user interface. Below are two illustrative examples of the systems use, firstly in a datacenter and secondly on a farm.
[0085] Datacenter Example: To populate the system ( FIG. 5 ), the assets are tagged with passive or active RFID tags. These tags are matched with the serial number of the asset to provide the database location; physical building location, room, rack and uPosition, asset information; manufacturer, model, configuration, power rating and other identification information. This information is gathered automatically through sensors and readers, passes through proprietary LightsOn API's and interfaces and then loads into the database. A user may also add assets manually to the database. Once the data capture has been complete the user can choose the manage, analyze, report or visualize options depending on the specific need. The locations can be selected and then asset information uniquely selected allowing any stakeholder, irrespective of their need to get the precise information they desire. This interface focuses on displaying not just the assets themselves, but also their key details and metrics. Once created, the “new datacenter” may be selected by picking it off the drop down bar in the menu window.
[0086] The Manage Capability
[0087] A Manage UI allows a user to see assets captured electronically and create and populate existing or new locations for assets manually. Manage then allows a user to view, analyze, add, change or delete assets. FIG. 6 shows the initial Manage template with a list of typical types of data being captured. Within Manage a user can see in detail the status of assets, which projects they are assigned to, their physical location, the contracts they were procured under, which RFID readers are tracking the asset and the RFID tags associated with the assets. A user can also manage and manipulate the racks in which assets are stored. FIG. 7-1 shows the Manage UI according to an embodiment of the invention.
[0088] Due to the 3 dimensional nature of assets and enclosures and their physical/geospatial attributes the system captures the location and orientation of each asset so that it can be identified and tracked on any movement. For example, FIG. 12-1 shows the Manage Capability for datacenter racks highlighting the orientation attributes captured for this type of enclosure including “X” and “Y” co-ordinates and the direction the front of the asset is facing. As another example, FIG. 16 highlights the orientation and geospatial data being captured in a farming scenario.
[0089] The Manage UI allows a user to filter, search and drill down on a specific asset to see the details of each asset that match the criteria selected. One can see information concerning the assets composition, tagging references, environmental factors, key dates, financial and contract information.
[0090] Specific Asset Drill Down
[0091] FIG. 7-2 illustrates a detail asset information or data entry screen.
[0092] The Report Capability
[0093] FIG. 8 shows the Report user interface according to an embodiment of the invention. A Report UI allows a user to select from any of the dimensions, properties or measures needed for any enquiry. The selectable properties and measures available appear in the user defined query and report builder section of the UI and user can apply conditional filters to these attributes as needed. User can further determine the layout of the report choosing which columns of information it will contain. Any multiple of these can be selected by a user.
[0094] Building Queries Using the GUI Report Builder
[0095] The Report UI allows the build out of uniquely required views of information by creating a user defined query that allows the selection of multiple properties to which can be applied selected filters, operators and values to further hone and qualify. These criteria can be added to build a “nested query” capability. This allows any authorized user, irrespective of their need to get the precise information they need. FIG. 9 shows a nested query example and the use of selectable drop down options that are available for each property, filter or operator specific to a single asset property or multiple data requirements to gain a specific user defined view. A user can select any of these attributes to report on by mousing over the property, clicking on it and picking the specific one needed. This process can be repeated with other properties and the user can decide where to position information by grabbing columns in the reported results at the bottom of the screen. Through this process a user builds custom reports, precisely containing the information they need and in the order and format they require.
[0096] Printing Reports and Exporting Queries
[0097] The Report UI allows a user, once the required view of information is reached, to save the query, print normally, create pivot tables, print as an Adobe .pdf format or download the specific information to Microsoft Excel. FIG. 10 shows Export Icons within Report.
[0098] GUI Tools to Select a Locate Criteria
[0099] A Visualize UI provides a three dimensional visualization of each location. One can select the location from those available in a drop down box and then use mouse controls tools to zoom in or out and pan/tilt tools. FIG. 11 shows location selection and navigation tools in the Visualize UI.
[0100] Users can filter their selection based on any information including asset type, manufacturer, age, owner, project etc. FIG. 12 shows Drop down filtering criteria.
[0101] In order to orientate and geospatially align assets within their enclosures, the system captures and employs physical location information. FIG. 12-1 is an illustrative example of the orientation and geospatial data captured for a rack enclosure within a datacenter including “X” “Y” co-ordinates and the direction in which the rack is facing. This data is used to virtually map the data center within the Visualize UI.
[0102] The Visualize UI provides a consistent drop-down capability to allow users to select the criteria for the assets they are looking for. FIG. 12-2 shows the HaloGlow effect based on the selection of a single filter attribute. Within this simple datacenter example, all racks containing assets with that filter criteria are highlighted with a HaloGlow. Those that have no matching assets are not highlighted enabling the differentiation between the two.
[0103] Once assets have been highlighted with HaloGlow, users can navigate through the datacenter to a specific asset using the 3D Walkthrough capability. FIG. 12-3 shows an example of Walkthrough zooming in to a specific asset and then accessing its more detailed attributes by a simple mouse over.
[0104] Three Dimensional Visualization
[0105] Once the filter criteria have been selected, the Visualize UI highlights where the assets that match those criteria are precisely located. By moving the cursor over each asset a “pop-up” box appears to give basic information on the asset in question. The filter criteria is automatically provided unique colors to enhance the user experience and see the varying conditions/ranges of that filter. FIG. 13 shows assets conforming to selection criteria.
[0106] Having established the filtering criteria and being able to see the results for a whole datacenter, a user can then zoom in on any specific rack location or asset as they see fit or navigate around the datacenter as if one was literally walking the aisle to see what assets conform to the query. FIG. 14 shows the specific information concerning one specific asset by positioning the cursor over the asset in question.
[0107] Integration Between Manage, Report and Visualize
[0108] Due to the full integration of all the embodiments of this solution a user can now click on a specific asset and see all its specific information. FIG. 15 shows by clicking on the asset the system provides complete details and every attribute pertaining to the asset including physical attributes, financial information, age and ownership in a single fully integrated view.
[0109] Farm Example ( FIG. 16 ) To populate the system in this example follows the exact same logic as that show in the datacenter example as does the use of the Manage Capability, Asset Filtering, Report Capability, User Defined Nested Report Builder, Printing Reports, Exporting Queries and GUI Tools. It further gives examples of the system Perimeter modeling capability that in this case would be used to map the extents of farms, fields, stable and stalls and the orientation and geospatial data captured.
[0110] From a visualize standpoint one can view the farm geospatially from the air selecting field or building locations. The zoom capability in this example allows closer scrutiny of certain building and the selection of one that is of interest. Once done the floor layout of the building is superimposed.
[0111] On entering the building the system allows comprehensive visualization in both 2D, 3D or both depending on which alternative best suits the application. In this example the image shows horses in stalls within the building.
[0112] As with the datacenter example one can monitor and manage information pertaining to the assets, in this case horses. Having established the filtering criteria and being able to see the results for a whole stable, a user can then zoom in on any specific stall or asset as they see fit or navigate around the stable as if one was literally walking the floor to see what assets conform to the query, in this case the horses' age.
[0113] Furthermore all the Report capabilities demonstrated in the earlier example would equally apply in this instance. As a result the system allows the selection from any of the dimensions or measures needed for any enquiry. A list of all the selectable dimensions and measures available appear in scrollable areas on the left hand side of the user interface. Any multiple of these can be selected by a user.
[0114] Finally due to the full integration of all the embodiments of this solution a user can now click on a specific horse and see all its specific information—see FIG. 17 .
[0115] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.
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A system for semantically modeling relationships and dependencies between groups, enclosures, assets, and support entities according to an industry specific manner. An exemplary system includes a user interface device, a relational database and a processor. The processor receives relationship information and receives attributes with associated measurements for the groups, enclosures, assets, and support entities for the corporation from the user interface device. The attributes with associated measurements are formatted according the specific industry of the corporation. The processor generates a three dimensional (3D) visualization of the groups, enclosures, assets, and support entities and allows a virtual walkthrough of the 3D visualization as presented on the display device based on user entered commands from the user input device.
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FIELD OF THE INVENTION
[0001] The present invention relates to electrodes, electrode components, apparatus comprising electrodes and to methods of manufacturing electrodes and electrode components as well as tubes and tubular bodies and to apparatus for use in said methods.
BACKGROUND TO THE INVENTION
[0002] There are known electrodes having a range of constructions and applications. Cold cathode electrodes for example have been found effective for lighting applications including cold cathode fluorescent lamps (CCFL) as backlights for LCD displays. However, such electrodes are of a small size and can thus be difficult to manufacture.
[0003] A known electrode comprises Molybdenum and has a tubular body which is blind at one end and to which end a stem (or pin) is attached. The tubular body is formed in a single part by a deep-drawing process and may consequently have a number of disadvantages.
[0004] The deep-drawing process can be inefficient resulting in wastage of materials and consequently increased manufacturing costs.
[0005] Additionally, with a deep drawing process the length of the tubular body may be restricted to a maximum of around 5 times its diameter. However, for longer electrode life and greater lamp brightness, longer electrodes having higher surface areas are desirable.
[0006] To improve the electrodes performance and/or lifespan it may also be desirable to coat the inner and/or outer surfaces of the tubular body. However, it may be difficult to coat the inside of the body, particularly if the body is long.
[0007] There thus remains a need for alternative electrodes and manufacturing methods.
[0008] Accordingly, the present invention aims to address at least one disadvantage associated with the prior art whether discussed herein or otherwise.
SUMMARY OF THE INVENTION
[0009] According to the present invention in a first aspect there is provided an electrode emission source component comprising an open ended tube and a cap wherein the tube is formed from a metal sheet which is formed into a tubular configuration and the cap is located onto the tube to form a tubular body which is blind at one end.
[0010] The metal sheet may be rolled into a tubular configuration. Suitably, the metal sheet is bent into a tubular configuration.
[0011] Suitably, the tubular body has a length of between 1 and 20 times its diameter, preferably between 3 and 15 times its diameter, for example around 10 times its diameter.
[0012] Suitably, the length of the tube is at least 5 times its diameter, for example at least 6, 7, 8, 9, 10, 11 or 12 times its diameter. Such ratios may result in a lamp comprising an electrode which comprises the electrode emission source component having a longer lifetime and/or greater brightness than lamps employing known electrodes.
[0013] Suitably, the electrode emission source component has an outer diameter of between 0.5 and 5 mm.
[0014] Suitably, the electrode emission source component has a length of between 0.5 and 12 mm.
[0015] Suitably, the cap has walls having a thickness of between 0.01 and 0.1 mm, preferably between 0.02 and 0.1 mm, for example around 0.055 mm.
[0016] Suitably, the metal sheet has a thickness of between 0.01 and 0.01 mm, preferably between 0.02 and 0.1 mm, for example around 0.08 mm. The tube may thus have a wall having a thickness of between 0.01 and 0.1 mm, preferably between 0.02 and 0.1 mm, for example around 0.08 mm. The wall may have double this thickness where edges of the metal sheet overlap.
[0017] Suitably, the tube has a substantially circular cross section.
[0018] Suitably, the tube comprises a bent metal sheet which is substantially planar prior to being formed into the tube.
[0019] Suitably, the tube comprises a bent metal sheet which is substantially rectangular prior to being formed into the tube.
[0020] Suitably, opposed first and second edges of the metal sheet lie substantially adjacent one another when formed into the tube.
[0021] Suitably, first and second edge regions of the metal sheet overlap when formed into the tube. The tube may thus have a double wall thickness at a seam which closes the tube circumferentially.
[0022] Suitably, the first and second edge regions of the metal sheet overlap by between 0.1% and 10% of the circumference of the tube, for example by between 0.5% and 8%.
[0023] Suitably, the cap comprises a unitary body. Suitably, the cap is formed by deep-drawing. Alternatively, the cap may be formed by extrusion.
[0024] Suitably, the cap comprises a generally cylindrical hollow form. Suitably, the cap comprises a tube which is blind at one end and open at the other.
[0025] Suitably, the cap holds the bent metal sheet in a tubular configuration. Suitably, the cap is arranged to locate over an end of the tube such that the tube fits snugly therein.
[0026] Suitably, the cap is located over the tube such that the cap overlaps an end region of the tube by between 0.1 and 30% of the tube length, preferably by between 0.5 and 20% of the tube length, for example by between 2 and 15% of the tube length.
[0027] Suitably, the cap overlaps the tube by between 0.1 mm and 10 mm. Suitably, the cap overlaps the tube by at least 0.1 mm, preferably by at least 0.3 mm, for example by at least 0.5 mm.
[0028] The overlap of the cap and tube may be arranged to provide an electrode emission source component having a double wall thickness at a region which may be prone to develop holes when the component is employed as an emission source in an electrode. This construction may thus result in the electrode component having a longer life than a component having a single thickness wall throughout its extent.
[0029] Suitably, the electrode component comprises one or more welds to secure the bent metal sheet in a tubular configuration. Suitably, one or more welds are formed to join overlapping parts of the metal sheet. Suitably, overlapping parts of the metal sheet are laser welded together. Suitably, the welds are spot welds.
[0030] Suitably, the cap is secured to the tube by one or more welds. Suitably, the cap is secured to the tube by a plurality of welds. Suitably, the tube and cap are laser welded together. Suitably, the welds are spot welds.
[0031] Suitably, the cap is secured to the tube by a first weld located at a region in which the first and second edges of the metal sheet overlap and in which the tube and cap overlap. Suitably, the tube and cap are secured by one or more further welds, preferably by two further welds spaced between 90 and 150 degrees, for example around 120 degrees, either side of the first weld.
[0032] The tube may comprise a metal sheet which comprises a pure metal. Alternatively, the tube may comprise a metal sheet which comprises an alloy.
[0033] Suitably, the metal sheet has a melting point of greater than 1100° C. Suitably, the metal sheet has a thermal conductivity of between 0.2 Watts/cm 2 .° C. and 5.0 Watts/cm 2 .° C. Suitably, the metal sheet has a coefficient of linear expansion of between 1×10 −6 /° C. and 30×10 −6 /° C. at ambient temperature.
[0034] Suitably, the tube comprises a metal sheet which comprises a transition metal. Suitably, the metal sheet comprises a metal selected from the group consisting of Nickel (Ni), Molybdenum (Mo), Niobium (Nb), Tantalum (Ta) and Tungsten (W). Suitably, the metal sheet comprises Molybdenum. Alternatively, the metal sheet may comprise Nickel which may be coated on at least one side.
[0035] The cap may comprise a pure metal. Alternatively, the cap may comprise an alloy.
[0036] Suitably, the cap has a melting point of greater than 1100° C. Suitably, the cap has a thermal conductivity of between 0.2 Watts/cm 2 .° C. and 5.0 Watts/cm 2 .° C. Suitably, the cap has a coefficient of linear expansion of between 1×10 −6 /° C. and 30×10 −6 /° C. at ambient temperature.
[0037] Suitably, the cap comprises a transition metal. The cap may comprise a metal selected from the group consisting of Nickel (Ni), Molybdenum (Mo), Niobium (Nb), Tantalum (Ta) and Tungsten (W). Suitably, the cap comprises Molybdenum.
[0038] The cap and tube may comprise the same metal. Alternatively, the cap and tube may comprise distinct metals. The tube and cap may thus be made from distinct materials chosen for their specific properties and functional performance in the overall electrode component combination.
[0039] The inner face of the electrode component may comprise a surface coating.
[0040] The surface coating may be provided on the tube and cap or just on the tube or just on the cap.
[0041] The tube may comprise a metal sheet which is provided with a surface coating on a first side and then formed into a tube such that said first side forms the inner face of the tube. Thus, it may be possible to form a tubular body having a tube of substantial length which is coated substantially evenly over its inner extent.
[0042] The surface coating may be arranged to improve the performance and/or lifespan of the electrode component.
[0043] The surface coating may have a thickness of between 0.001 mm and 0.1 mm.
[0044] The surface coating may comprise micro and/or nano sized particles to increase the surface area of the electrode component. This may result in higher brightness and/or lower operating temperatures for lamps employing electrodes comprising the electrode emission source component.
[0045] The surface coating may comprise a metal which has a higher activity than the metal forming the component that it coats. A metal having a higher activity may have an increased resistance to ion bombardment and/or improved electron emission properties which may be due to the metal having a lower work function and/or higher electrical conductivity. The surface coating may comprise Molybdenum or Tungsten or other suitable elements or alloys. The electrode emission source component may thus be constructed from a cap and/or tube comprising a metal, such as Nickel, coated with a more active but more expensive metal, such as Molybdenum or Tungsten. This may allow effective electrodes to be manufactured more economically.
[0046] The surface coating may comprise a material having a low work function and/or high resistance to ion bombardment. The surface coating may for example comprise diamond or polycrystalline silicon.
[0047] The outer face of the electrode component may comprise a surface coating.
[0048] The surface coating may be provided on the tube and cap or just on the tube or just on the cap.
[0049] The tube may comprise a metal sheet which is provided with a surface coating on a second side and then formed into a tube such that said second side forms the outer face of the tube.
[0050] The surface coating may be arranged to improve the performance and/or lifespan of the electrode component.
[0051] The surface coating may comprise a coating as described in relation to the inner face of the electrode emission source component.
[0052] The surface coating applied to the outer face may be the same as that applied to the inner face or may be distinct there from. Thus, a surface coating applied to the second side of the metal sheet may be the same as that applied to a first side of the metal sheet or may be distinct there from.
[0053] A surface coating may be applied to a part of the electrode emission source component by a number of known methods, for example any of sputter coating, electrochemical deposition, metal-organic vapour phase deposition, in-situ precipitation, sol-gel processes, spraying, brushing or coil coating may be suitable.
[0054] Once the coating is applied it may be necessary to convert it to a suitable metallic form by a thermal and/or chemical treatment before the part of the electrode emission source component is employed to manufacture the electrode emission source component.
[0055] The tube may comprise a metal sheet which is provided with a surface coating which is then converted into a suitable metallic form prior to the metal sheet being formed into a tube.
[0056] According to a second aspect of the present invention there is provided an electrode comprising an electrode emission source component according to the first aspect and a stem attached to the cap of the electrode emission source component.
[0057] The stem may be formed integrally with the cap. The stem may be welded to the cap.
[0058] Suitably the stem extends substantially parallel to the axis of the tube. Suitably, the tube and stem have a substantially common axis.
[0059] The stem may comprise a pure metal. Alternatively, the stem may comprise an alloy.
[0060] Suitably, the stem has a melting point of greater than 1100° C. Suitably, the stem has a thermal conductivity of between 0.2 Watts/cm 2 .° C. and 5.0 Watts/cm 2 .° C. Suitably, the stem has a coefficient of linear expansion of between 1×10 −6 /° C. and 30×10 −6 /° C. at ambient temperature.
[0061] Suitably, the stem comprises a transition metal. The stem may comprise a metal selected from the group consisting of Nickel (Ni), Molybdenum (Mo), Niobium (Nb), Tantalum (Ta) and Tungsten (W). The stem may comprise KOVAR (an Iron, Nickel, Cobalt and Chromium alloy).
[0062] Suitably, the stem comprises the same material as the cap.
[0063] Suitably, the electrode comprises a glass ring mounted on the stem. The glass ring may provide an attachment point by which the electrode may be secured into a housing.
[0064] According to a third aspect of the present invention there is provided an electrical apparatus comprising an electrode according to the second aspect.
[0065] The electrical apparatus may comprise a lighting apparatus. The electrical apparatus may comprise a cold-cathode fluorescent lamp, used for example in a back light for an LCD display.
[0066] According to a fourth aspect of the present invention there is provided an apparatus for forming a tube by bending a metal sheet, the apparatus comprising a forming station comprising a forming pin around which said metal sheet can be wrapped and a plurality of form fingers radially spaced around the forming pin and moveable relative to the forming pin for wrapping the metal sheet around the forming pin.
[0067] Suitably, the forming pin comprises a cylinder having a circular cross-section. Suitably, the axis of the forming pin is arranged to extend substantially vertically.
[0068] Suitably, the apparatus is arranged to locate the metal sheet substantially tangentially to the forming pin.
[0069] Suitably, each form finger is moveable relative to the axis of the forming pin.
[0070] Suitably, the apparatus comprises three or more, for example four or more form fingers. Suitably, the apparatus comprises only four form fingers.
[0071] Suitably, the apparatus comprises feed means arranged to feed a metal sheet to the forming station.
[0072] Suitably, the metal sheet comprises a metal tape. The feed means may thus be arranged to feed metal tape to the forming station.
[0073] Suitably, the apparatus comprises a cutter arranged to cut a length of tape from a supply of tape to provide a metal sheet which can be formed into a tube.
[0074] Suitably, the apparatus is arranged to feed a metal tape from a tape supply to the forming station and then cut the tape to provide a metal sheet, by separating a length of tape from the tape supply, and then form the metal sheet into a tube.
[0075] Suitably, the feed means is arranged to feed the metal tape into the forming station substantially tangentially to the forming pin.
[0076] Suitably, the apparatus is arranged such that the metal tape is fed into the forming station such that it lies near to, suitably within 5 mm, preferably within 0.1 mm of the forming pin. Suitably the apparatus is arranged such that the metal tape substantially does not engage the forming pin as it is fed into the forming station.
[0077] Suitably, a first form finger is arranged to move substantially perpendicular to the direction in which the metal tape is fed into the forming station.
[0078] Suitably, the first form finger is moveable substantially linearly. Suitably, the first form finger is moveable substantially perpendicularly to the axis of the forming pin.
[0079] Suitably, the first form finger is moveable to a clamping position such that it can clamp the metal tape against the forming pin to hold it in position substantially without deforming the tape. The tape may thus be held in position whilst a length of tape is cut by the cutter to form the metal sheet.
[0080] Suitably, the apparatus is arranged such that once a length of tape is cut by the cutter to form the metal sheet the metal sheet may be held in position by the forming pin and first form finger.
[0081] Suitably, the apparatus is arranged such that during the tube forming process at any given time whilst the metal sheet is being wrapped around the forming pin a part of the metal sheet is clamped between the forming pin and a form finger. Thus, the apparatus may be arranged to precisely form tubes.
[0082] Suitably, the first form finger is moveable to a wrapping position in which it can cause the metal sheet to bend around the forming pin. Suitably, the first form finger is arranged to engage a mid region of the metal sheet.
[0083] Suitably, the wrapping position of the first form finger lies closer to the forming pin than the clamping position. The metal sheet may thus remain clamped between the first form finger and forming pin when the form finger is in the wrapping position.
[0084] Suitably, the first form finger comprises a tip having a forming face. Suitably, the forming face comprises a concave arc arranged to engage the metal sheet when in the wrapping position.
[0085] Suitably, the forming face comprises an arc of around 180 degrees.
[0086] Suitably, the forming face is arranged to substantially correspond to the outer surface of the forming pin.
[0087] Suitably, the first form finger is arranged to wrap the metal sheet around the forming pin to form a U shaped arc, suitably of around 180 degrees.
[0088] The first form finger may be mounted to an actuator arranged to move it linearly relative to the axis of the forming pin.
[0089] Suitably, the first form finger remains in contact with the metal sheet from the time it first engages the sheet until the sheet has been wrapped into a tube.
[0090] The apparatus may be arranged such that the tape is fed and cut to provide a cut edge lying closer to the clockwise side of the first form finger than to the anti-clockwise side thereof. Alternatively, the apparatus may be arranged such that the tape is fed and cut to provide a cut edge lying closer to the anti-clockwise side of the first form finger than to the clockwise side thereof.
[0091] The form fingers suitably operate sequentially and their relative positions may depend upon the direction from which the tape is fed. For convenience, all references to relative directions herein relate to a situation in which the tape is fed from a clockwise side of the form finger. It will however be appreciated that the alternate embodiment in which the tape is fed from an anti-clockwise side of the form finger are encompassed by the present invention.
[0092] Suitably, the apparatus comprises a second form finger. Suitably, the second form finger is arranged to move substantially linearly. Suitably, the second form finger is arranged to move substantially perpendicularly to the axis of the forming pin.
[0093] Suitably, the second form finger has a tip having a forming face. Suitably, the forming face comprises a concave arc.
[0094] Suitably, the forming face comprises an arc of around 30 degrees.
[0095] Suitably, the forming face is arranged to substantially correspond to the outer surface of the forming pin.
[0096] The second form finger may be mounted to an actuator arranged to move it linearly relative to the axis of the forming pin.
[0097] Suitably, the second form finger is arranged to move on a path which is radially disposed relative to the path on which the first form finger is arranged to move by between 70 and 110 degrees, for example by around 90 degrees. Suitably, the second form finger is radially disposed relative to the first form finger by said angle in an anti-clockwise direction.
[0098] Suitably, the second form finger is arranged to move substantially perpendicularly to the first form finger.
[0099] Suitably, the second form finger is moveable to a wrapping position in which it can cause a metal sheet to bend around the forming pin. Suitably, the second form finger is arranged to engage a first edge region of the metal sheet.
[0100] Suitably, the metal sheet is clamped between the second form finger and the forming pin when the second form finger is in the wrapping position.
[0101] Suitably, the apparatus comprises a third form finger. Suitably, the third form finger is arranged to move axially relative to the forming pin. Suitably, a tip of the third form finger is arranged to move on an arcuate path as it approaches the forming pin.
[0102] Suitably, the third form finger is arranged to move on a path which is substantially equidistantly spaced from that of the first and second form fingers.
[0103] Suitably, the third form finger is arranged to move on a path which is radially disposed relative to the path on which the first form finger is arranged to move by between 100 and 160 degrees, for example by around 130 to 140 degrees. Suitably, the second form finger is radially disposed relative to the first form finger by said angle in a clockwise direction.
[0104] Suitably, the third form finger has a tip having a forming face. Suitably, the forming face comprises a concave arc.
[0105] Suitably, the forming face comprises an arc of around 90 degrees.
[0106] Suitably, the forming face is arranged to substantially correspond to the outer surface of the forming pin.
[0107] Suitably, the third form finger is moveable to a wrapping position in which it can cause a metal sheet to bend around the forming pin. Suitably, the third form finger is arranged to engage the metal sheet between a mid region, engaged by a first form finger, and a second edge region of the metal sheet.
[0108] Suitably, the metal sheet is clamped between the third form finger and the forming pin when it is in the wrapping position.
[0109] Suitably, the third form finger is arranged to move generally perpendicularly to the axis of the forming pin but for a tip thereof to follow an arcuate path as it approaches the forming pin.
[0110] The third form finger may be mounted to an actuator arranged to move it linearly relative to the axis of the forming pin. The third form finger may be pivotally mounted to the actuator and the apparatus may comprise an engagement pin arranged to engage the third form finger and cause it to pivot relative to the actuator as it approaches a wrapping position. The tip of the second form finger may thus be caused to follow an arcuate path as it moves towards the forming pin and rotates relative to the actuator and forming pin simultaneously. This action may minimise the risk of the third form finger creating kinks in the metal sheet as it engages it.
[0111] Suitably, the third form finger remains in contact with the metal sheet from the time it first engages the sheet until the sheet has been wrapped into a tube.
[0112] Suitably, the third form finger is arranged to move to its wrapping position after the first and second form fingers move to their wrapping positions.
[0113] Alternatively, the third form finger may be arranged to move to its wrapping position after the first form finger moves to its wrapping position but before the second form finger moves to its wrapping position.
[0114] Suitably, the apparatus comprises a fourth form finger. Suitably, the fourth form finger is arranged to move linearly. Suitably, the fourth form finger is arranged to move substantially perpendicularly to the axis of the forming pin.
[0115] Suitably, the fourth form finger has a tip having a forming face. Suitably, the forming face comprises a concave arc.
[0116] Suitably, the forming face comprises an arc of around 70 degrees.
[0117] Suitably, the forming face is arranged to substantially correspond to the outer surface of the forming pin.
[0118] The fourth form finger may be mounted to an actuator arranged to move it linearly relative to the axis of the forming pin.
[0119] Suitably, the fourth form finger is arranged to move on a path which is radially disposed relative to the path on which the first form finger is arranged to move by between 100 and 150 degrees, for example by around 130 to 140 degrees. Suitably, the fourth form finger is radially disposed relative to the first form finger by said angle in an anti-clockwise direction.
[0120] Suitably, the fourth form finger is moveable to a wrapping position in which it can cause a metal sheet to bend around the forming pin. Suitably, the fourth form finger is arranged to engage the metal sheet near to a second edge region thereof.
[0121] Suitably, the apparatus is arranged such that the second form finger is removed from contact with the metal sheet before the fourth form finger engages the metal sheet. Suitably, the first and third form fingers remain in contact with the metal sheet.
[0122] Suitably, the metal sheet is clamped between the fourth form finger and the forming pin when the form finger is in the wrapping position.
[0123] Suitably, the apparatus is arranged such that once the fourth form finger is in the wrapping position first and second edges of the metal sheet substantially overlie one another.
[0124] Suitably, the apparatus is arranged such that once the fourth form finger has been moved to a wrapping position the second form finger can be returned to a wrapping position. The second form finger may thus cause the second edge region of the metal sheet to be wrapped over the first edge region thereof. The second edge region may be clamped over the first edge region to form a circumferentially closed tube.
[0125] Suitably, the apparatus further comprises handling means for holding the metal sheet in the tubular configuration as the form fingers are removed from engagement therewith once the tube is formed.
[0126] Suitably, the handling means comprises a collet assembly arranged to clamp the tube. Suitably, the collet assembly is arranged to engage the outside of the tube around substantially the entirety of its circumference. The collet assembly may be arranged to allow the tube to open slightly to release cleanly from around the forming pin.
[0127] Suitably, the apparatus comprises a welding station at which the bent metal sheet may be welded to secure it in a tubular configuration. The welding station suitably comprises means for laser welding.
[0128] The handling means may be arranged to convey the tube to the welding station.
[0129] Suitably, the apparatus comprises means to install a cap to the end of the tube to form a tubular body which is blind at one end.
[0130] Suitably the apparatus is arranged to install the cap before the tube is conveyed to a welding station. Suitably, the tube may be welded to the cap at the welding station.
[0131] Suitably, the handling means is arranged to locate the tube into a cap. The collet assembly may be arranged to decrease the tube diameter slightly and insert it into a cap and then allow the tube to open slightly to seat snugly in the cap. The collet assembly may then release the tube.
[0132] A further handling means may then convey the tubular body to a welding station. For example, the cap may be held by a further handling means which can convey it and the tube to a welding station.
[0133] Suitably, the apparatus is arranged to produce an electrode emission source component according to the first aspect.
[0134] The apparatus may further comprise means for attaching a stem to a cap or may be arranged to handle a cap having a stem attached thereto. The apparatus may thus be arranged to manufacture an electrode according to the second aspect.
[0135] According to a fifth aspect of the present invention there is provided a method of forming a tube, the method comprising wrapping a metal sheet around a forming pin such that the metal sheet adopts a tubular configuration substantially corresponding to the outer face of the forming pin.
[0136] Suitably, the metal sheet is wrapped around a forming pin by a plurality of form fingers. The form fingers may press the metal sheet against the forming pin to form the tube.
[0137] Suitably, the forming pin comprises a substantially circular cross section. Alternatively, the form finger may comprise a square, rectangular or triangular cross section.
[0138] The metal sheet may be such that once formed into the tubular configuration it substantially retains said configuration.
[0139] The method may comprise the step of securing the metal sheet in the tubular configuration. Said securement step may comprise welding edges of the metal sheet together in the tubular configuration.
[0140] Alternatively, or in addition, the securement step may comprise installing a cap onto the tube which may hold the metal sheet in the tubular configuration. The tube and cap may be welded together. The method may thus comprise forming a tubular body which is blind at one end.
[0141] The tubular body formed by the method may comprise an electrode emission source component according to the first aspect.
[0142] A stem may be attached to the cap and the method may thus comprise a method of manufacturing an electrode.
[0143] Suitably, the method comprises wrapping a mid region of a metal sheet around a forming pin and then wrapping a first edge region of the metal sheet around a forming pin and then wrapping the remainder of the metal sheet around the forming pin such that a second edge region of the metal sheet overlaps the first and the metal sheet forms a tube.
[0144] Suitably, the method employs an apparatus according to the fourth aspect. The method may employ any step referred to in relation to the fourth aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0145] The present invention will now be illustrated by way of example with reference to the accompanying drawings in which:
[0146] FIG. 1 is a perspective view of an electrode emission component;
[0147] FIG. 2 is a cross section of the electrode emission component of FIG. 1 showing hidden detail;
[0148] FIG. 3 is an end view of the electrode emission component of FIG. 1 ;
[0149] FIG. 4 is a plan view of a forming station of an assembly apparatus;
[0150] FIG. 5 is a detail plan view of a part of the forming station of FIG. 4 ;
[0151] FIGS. 6A-H are schematic representations of a tube forming operation;
[0152] FIG. 7 is a cross section of a collet assembly of a handling means;
[0153] FIG. 8 is an end view of part of the collet assembly of FIG. 7 holding a tube; and
[0154] FIG. 9 is a cross section of a cold-cathode fluorescent lamp comprising the electrode emission source component of FIGS. 1 to 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0155] As illustrated by FIGS. 1 to 3 an electrode emission source component 1 comprises a tubular body 3 which is blind at a first end 5 and open at an opposed second end 7 . The tubular body 3 comprises a tube 9 formed from a bent metal sheet 11 and a cap 13 into which the tube 9 is inserted.
[0156] The cap 13 itself comprises a tubular body which is blind at one end and comprises a cylindrical wall 15 extending from a base wall 17 .
[0157] The cap 13 comprises molybdenum and is formed by deep-drawing.
[0158] The metal sheet 11 comprises molybdenum and is fabricated into a tube 9 by being bent. The metal sheet 11 is bent such that first and second edge regions 19 , 21 thereof overlap. A first side 25 of the metal sheet forms an inner face 29 of the electrode emission source component 1 and a second side 27 forms an outer face 31 thereof.
[0159] The cap 13 and tube 9 are laser welded at weld points 23 to secure the cap 13 to the tube 9 and to retain the metal sheet 11 in a tubular configuration. A first weld point is located within a zone in which the cap 13 and edge regions 19 , 21 of the tube 9 overlap. Two further weld points are spaced around the cap 13 within a zone which overlaps with the tube 9 such that they lie approximately 120 degrees either side of the first weld point. An additional weld point is located at the second end 7 of the tubular body 3 within a zone in which the edge regions 19 , 21 overlap.
[0160] The electrode emission source component 1 has a length of around 5 mm and a diameter of around 1 mm.
[0161] FIG. 9 illustrates a cold cathode fluorescent lamp 201 comprising an electrode 203 comprising electrode emission source components 1 each having a stem 205 attached thereto. The lamp 201 comprises a glass body (housing) 207 through which the stems 205 extend. The interior of the glass body 207 is provided with a phosphor coating 209 and the body 207 is evacuated and charged with a small quantity of mercury.
[0162] The tube 9 can be fabricated using apparatus illustrated by FIGS. 4 and 5 .
[0163] The apparatus 100 comprises a forming station 102 comprising a pin 101 having a substantially circular cross section and which is orientated such that its axis extends substantially vertically. Arranged around the forming pin 101 at the forming station 102 are first, second, third and fourth form fingers 110 , 120 , 130 140 . Each form finger 110 , 120 , 130 , 140 is mounted upon an actuator 111 , 121 , 131 , 141 arranged to move the respective form finger substantially linearly and perpendicularly relative to the axis of the forming pin 101 .
[0164] Each form finger 110 , 120 , 130 , 140 comprises a tip 113 123 , 133 , 143 having a forming face 115 , 125 , 135 , 145 comprising a convex arc. Said forming faces are arranged to generally correspond to the outer face 103 of the forming pin.
[0165] In use, the form fingers 110 , 120 , 130 , 140 are moveable to wrapping positions in which they can cause a metal sheet to be bent around the forming pin 101 . The form fingers are radially spaced from one another around the forming pin 101 such that when in a wrapping position their forming faces form a ring, which has only minor gaps, around the forming pin 101 .
[0166] As well as being moveable relative to the forming pin 101 the third form finger 130 is also pivotable relative to the third actuating means 131 . This is achieved by the third form finger 130 being mounted to the third actuating means about a pivot 137 . The third form finger 130 is also provided with an arm 139 arranged to engage an engagement pin 105 as the tip of the form finger is moved towards the forming pin 101 . The engagement pin 105 is axially fixedly positioned relative to the forming pin 101 . Thus, in use, as the arm engages the actuating pin it is restricted from moving towards the forming pin 101 , continued movement of the third form finger 130 towards the forming pin 101 by the actuator 131 thus causes the form finger 130 to rotate about pivot 137 . The tip 133 of the third form finger 130 may thus follow an arcuate path as it approaches the forming pin 101 . This movement may, in use, minimise any kinking of the metal sheet as it is bent around the forming pin 101 .
[0167] In addition to the forming station 102 the apparatus comprises feed means (not shown) for feeding metal tape 150 from a supply of tape to the forming station. A cutter 170 (shown schematically in FIGS. 6A-G ) is provided to cut a length from the tape 150 to provide a metal sheet 11 .
[0168] The apparatus also comprises a handling means for conveying a formed tube from the forming station 102 . The handling means comprises a collet assembly 160 (illustrated by FIGS. 7 and 8 ) arranged to hold the metal sheet 11 in a tubular configuration once the tube 9 is formed.
[0169] The collet assembly 160 comprises three segments 161 arranged to form a circular aperture 163 at their centre to receive the tube 9 and lightly grip it. The collet assembly 160 may thus convey the tube 9 substantially without deforming it. To release the tube 9 the segments 161 can be moved apart to enlarge the aperture 163 . The collet assembly further comprises an ejector pin 165 for pushing the tube 9 from the collet assembly's grip.
[0170] To provide the electrode emission source component illustrated by FIGS. 1 to 3 the apparatus is arranged such that the collet assembly 160 inserts an end of the tube 9 into a cap 13 and then releases the tube 9 . The tube 9 can then open out slightly to seat snugly in the cap 13 . The apparatus further comprises a further handling means (not shown) arranged to convey the cap and tube to a welding station (not shown) to secure them together and secure the metal sheet 11 in a tubular configuration.
[0171] In an alternative embodiment, not illustrated, the apparatus may form a tube 9 having no cap by conveying a bent metal sheet 11 to a welding station to secure the sheet in a tubular configuration.
[0172] The tube forming process is best illustrated by FIGS. 6A-H which schematically represent the movement of the form fingers.
[0173] To form a tube 9 from a metal sheet 11 a length of tape 150 is first fed to a forming station 102 with the forming pin 101 and form fingers 110 , 120 , 130 , 140 arranged generally as illustrated by FIG. 6A .
[0174] As illustrated by FIG. 6B the first form finger 110 then moves toward the forming pin 101 to adopt a clamping position in which the tape 150 is held between the form finger and forming pin. When the first form finger 110 is in the clamping position only prongs 117 on the tip 113 of the form finger (defining edges of the forming face 115 ) engage the tape 150 . Thus the tape is substantially un bent. With the tape 150 clamped between the form finger and forming pin the cutter 170 moves to a cutting position to cut a length from the tape 150 to provide a metal sheet 11 which is substantially planar and has opposed first and second edge regions 19 , 21 .
[0175] As illustrated by FIG. 6C the cutter 170 then retracts to a non-cutting position and the first form, finger 110 moves closer to the forming pin 101 to reach a wrapping position. When the form finger is in the wrapping position a first (inner) face 25 of the metal sheet 11 is pressed against the forming pin 101 and a second (outer) face 27 of the metal sheet is pressed against the forming face 115 of the first forming finger 110 . A mid region of the metal sheet 11 is thus caused to wrap around the forming pin 101 .
[0176] As illustrated by FIG. 6D the second form finger 120 is then moved to a wrapping position in which the first edge region 19 of the metal sheet 11 is pressed between the outer face 103 of the forming pin 101 and the forming face 125 of the second form finger. The edge region 19 is thus wrapped around the forming pin 101 .
[0177] Next, as illustrated by FIG. 6E the third form finger 130 is moved to a wrapping position in which a further mid-region of the metal sheet 11 is pressed between the outer face 103 of the forming pin 101 and the forming face 135 of the second forming finger. The further mid-region is thus wrapped around the forming pin 101 . The second form finger 120 is removed from engagement with the metal sheet 11 at this time such that it does not subsequently interfere with the wrapping of the remainder of the metal sheet 11 .
[0178] As illustrated by FIG. 6F the fourth form finger 140 then moves to a wrapping position in which a region near the second edge 21 a of the metal sheet 11 is pressed between the outer face 103 of the forming pin 101 and the forming face 145 of the fourth forming finger. The metal sheet 11 is thus wrapped around the forming pin 101 such that the second edge region 21 overlies the first edge region 19 .
[0179] To complete the tube 9 the second form finger is returned to a wrapping position as illustrated by FIG. 6G such that the second edge region 21 of the metal sheet 11 is pressed between the outer face 103 of the forming pin 101 and the forming face 145 of the second forming finger. The second edge region 21 of the metal sheet and the forming pin 101 are interposed by the first edge region 19 of the metal sheet 11 and thus the metal sheet 11 is wrapped to form a tube 9 .
[0180] As shown by FIG. 6H the first and fourth form fingers 110 , 140 are taken out of engagement with the metal sheet 11 such that the metal sheet 11 is held in a tubular configuration by the second and third form fingers 120 , 130 and the forming pin 101 .
[0181] To form an electrode component the following steps are then performed.
[0182] The collet assembly 160 is located over the forming pin in an open configuration. The forming pin 101 then raises substantially vertically lifting the tube 9 partially clear of the second and third form fingers 120 , 130 and into the aperture 163 of the open collet assembly 160 . The second and third form fingers 120 , 130 are then moved away from the tube 9 which thus expands slightly into the open collet assembly 160 . The forming pin 101 is then lowered away from the tube. The collet assembly 160 then closes to reduce the aperture 163 and thus tube 9 to a diameter which is slightly smaller than that of a cap 13 into which the tube 9 is to be inserted.
[0183] The collet assembly 160 then conveys the tube 9 to a cap 13 and an ejector pin 165 ejects the tube 9 into the cap 13 and the collet assembly 160 opens to enlarge aperture 163 and withdraws. The tube 9 is pushed into the cap 13 to the required extent to control the overall length of the tubular body 3 thus formed and then a welding operation is performed.
[0184] A polycrystalline diamond pin (not shown) is inserted into the open end of the body 3 for the full length of the body 3 to act as a heat and vapour sink. A gas mixture of 90% Nitrogen and 10% Hydrogen or Argon is then applied as a shielding/reducing gas. Three laser spot welds 23 are then produced simultaneously through the cap 13 into the tube 9 , 120 degrees apart with one weld 23 centred on the overlapping edges 19 , 21 of the metal sheet 11 of the tube 9 . The polycrystalline diamond pin is then removed from the component.
[0185] The open end of the tubular body 3 is then clamped using two semi circular control jaws (not shown) to give the correct diameter and shape and a laser spot weld is produced perpendicular to the tube 9 centred on the overlapping edges 19 , 21 of the metal sheet 11 adjacent the open second end 7 .
[0186] It will be appreciated that electrode emission source components according to preferred embodiments of the present invention may be advantageous. In particular, they may be efficient to produce and may have enhanced lifetimes compared to known components.
[0187] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
[0188] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0189] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0190] The invention is not restricted to the details of the foregoing embodiments(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
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There is provided apparatus ( 100 ) for forming a tube ( 9 ) by bending a metal sheet ( 11 ). The apparatus ( 100 ) comprises a forming station ( 102 ) comprising a forming pin ( 101 ) around which a metal sheet ( 11 ) can be wrapped and a plurality of form fingers ( 110, 120, 130, 140 ) radially spaced around the forming pin ( 101 ) and moveable relative thereto. Also provided are electrode emission source components ( 1 ) The components ( 1 ) comprise an open ended tube ( 9 ) and a-cap ( 13 ), wherein the tube ( 9 ) is formed from* a metal sheet ( 11 ) which is formed into a tubular configuration. Further provided are electrodes, electrical apparatus and methods of forming tubes.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotary blade capable of a damping of noises generated during rotation, and further relates to a construction of the rotary blade useful for cutting a stone, concrete, asphalt and the like.
2. Prior Art
A rotary blade capable of damping noises has been disclosed in Japanese Patent Publication No. Sho 50-10040. In this rotary blade, a plurality of grooves having a suitable width, for example 1.5 m, and a suitable length, for example about 10% of an outside diameter of a saw member, are formed at regular intervals from the vicinity of a base portion toward almost a center of the blade on a circumferential edge of the rotary substrate. The respective grooves are filled with setting synthetic resins having a hardness lower than that of the rotary substrate to fixedly mount the setting synthetic resins on the grooves.
It has been described that, according to this construction, low sound waves generated from the setting synthetic resin layer interfere with sound waves generated from the blade to hinder the tuning and resonance of sound waves, thereby changing simple high sounds to complicated low sounds, and thus high and sharp metal sounds are deadened, as a whole.
The blade formed on the circumferential portion of the rotary substrate is rotated at a high speed to produce a turbulent air flow, thereby generating sounds. The blade thus receives an external force resulting from the generation of this turbulent flow to be vibrated, or receives an external force resulting from a load on a material to be cut to be compulsorily vibrated, and thus this vibration is resonant with vibration of the rotary substrate to generate large sounds. According to the Japanese Patent Publication No. Sho 50-10040, a plurality of grooves are formed from the vicinity of the base portion toward almost the center of the blade portion and filled with setting synthetic resins having a hardness lower than that of the blade to act as a buffer zone for the propagation of vibration, thereby partially stopping the propagation of vibration in the rotary substrate, and thus reducing also the resonance.
However, according to the Japaneses Patent Publication No. Sho 50-10040, the buffer zone of vibration is arranged in a radial direction from the center, so that the vibration resulting from the blade portion is damped in the circumferential direction on the rotary substrate, but the vibration generated in the blade portion is reflected in the central portion, whereby the generated vibration can not be sufficiently damped.
OBJECTS AND SUMMARY OF THE INVENTION
In view of the above described problems, it is an object of the present invention to damp the vibration resulting from the blade (saw toothed-portion) in the circumferential portion of the rotary substrate causing the increased vibration in not only the circumferential direction on the rotary substrate but also the direction toward the center from the circumferential portion of the rotary substrate.
In order to achieve the above object, in a rotary blade in which a number of chips formed with super grinding diamond particles integrally by a metallic bond material are placed at an internal on an outer edge of the rotary substrate a plurality of first semicircular slits open toward a center of rotation of the substrate are formed at regular intervals with a first circumference positioned in the vicinity of an outer edge of the rotary substrate. A plurality of second semicircular slits open in a direction opposite to the direction, in which the first slits open partially interrupting the direction, in which the first slits open. The second slits are formed at a second circumferential position inside the first slits. All of the slits are filled with fillers to integrate the slits with the rotary substrate.
In addition, according to the present invention, a large number of grooves are formed in the outer circumference of the substrate and similarly filled with fillers.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described below in more detail with reference to a preferred embodiment shown in the accompanying drawings, wherein:
FIG. 1 is a plan view showing a preferred embodiment of a rotary substrate for use in a blade according to the present invention;
FIG. 2(a) is an enlarged view showing portion B--B in FIG. 1;
FIG. 2(b) is an enlarged partial sectional view of FIG. 1 taken along line A--A thereof;
FIGS. 3(a), and (b) are diagrams showing a preferred embodiment of a rotary blade according to the present invention;
FIG. 4 is a perspective view describing a cassette structure of the blade;
FIG. 5 is a side view of FIG. 4; and
FIG. 6 is a side view showing a conventional cassette structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the whole of a rotary substrate for use in a rotary blade according to the present invention.
Reference numeral 1 designates the rotary substrate, formed of a punched steel plate or stainless steel plate in a circular shape. Reference numeral 2 designates an axial hole formed at a center of the rotary substrate 1, reference numeral 3 designates a blade, and reference numerals 4 and 5 designate first and second semicircular slits, respectively.
FIG. 2(a) is an enlarged view showing a portion surrounded by lines B--B in FIG. 1 and FIG. 2(b) is an enlarged sectional view of FIG. 1, taken along line A--A thereof. Referring to FIG. 2(b) reference numeral 6 designates fillers.
As shown in FIG. 1, the present preferred embodiment 24 first slits 4 and 12 second slits 5 are formed. The thickness of the substrate is, for example, 4 to 9.5 mm, and the diameter is, for example, 30 to 100 inches (75 to 254 cm).
A first circumference 7 is established in the vicinity of an outer edge of the rotary substrate 1, with the center of the rotary substrate 1 as 0 the 24 semicircular slits 4 are formed all about the outside circumference of the first circumference 7. An interval d between ends 9 and 9' of adjacent slits 4 is set so as to be smaller than 2 times an inside radius r of the formed semicircular slits 4.
The respective semicircular slits 4 have a shape opening in a direction toward the center 0 of the rotary substrate 1, and may have a circular arc slightly larger or smaller than a semicircle.
These semicircular slits 4 are formed by means of a laser processing machine so as to be made round at both end portions thereof. A slit width of about 0.4 mm is suitable.
The slits, which have been formed in the above described manner, are referred to as the first semicircular slits.
Subsequently, a second circumference 8 is established inside of the first circumference 7, with the center 0 as a fundamental point, and 12 semicircular slits 5, which open in a direction opposite to the direction in which the adjacent slits 4 open (slits 5 opening outward). The slits 5 simultaneously cross over both end portions 9 and 9' to partially interrupt the direction in which the adjacent slits 4 to open, and are formed for every two adjacent slits 4 inside of the circumference 8. The circumference 8, the radii connecting both end portions 9 and 9' of the first adjacent semicircular slits 4 and the center 0 of the substrate are standards.
The processing and the width of the slits 5 are same as those of the slits 4.
In the above described case, a difference l between the first circumference 7 and the circumference 8 in diameter is dependent upon the mechanical strength of the rotary substrate 1 when subjected to a cutting load.
The shape and arrangement of the slits lead to the possibility that the whole length of the slits themselves can be increased without decreasing the rigidity of the substrate (the rigidity of the substrate for holding the blade within an appointed plane during a high-speed rotary grinding) operation, thereby increasing the quantity of fillers and improving the sound damping effect.
In addition, the semicircular slits 4 and 5 may be the same or slightly different in diameter.
All of the semicircular slits 4 and 5 are filled with fillers obtained by compounding heat resistant, pressure resistant and shake-proof sealing agents to synthetic resins. The most suitable synthetic resins for filling have, hardness which can be regulated, ranging from a rigid state to a flexible state, and are water-proof to such an extent that they are difficult to dissolve in cutting water. Further, a strong adhesion to metals, to such an extent that they do not fall out by centrifugal force due to the high rotation frequency, and a low viscosity required for easy filling, are most suitable. The sealing agents used contain, for example, asbestos and glass fibers. The fillers are adapted to have a hardness lower than that of the rotary substrate after setting.
Referring to FIG. 1 and FIGS. 2(a), (b) and the blade 3 is formed by fixedly brazing and welding chips, which have been obtained by sintering diamond particles integrally with metals, to stand portions formed by U-shaped grooves 10 on an outer edge of the substrate 1 at regular intervals or by a cassette construction.
The cassette construction of the blade is here described in detail. A cutting chip has been directly fixed to the substrate in many cases, but as disclosed in Japanese Utility Model Laid-Open No. Sho 62-198058, a chip which is detachable by means of a fixture, the chip having a dovetail groove type cassette construction, has been known.
Of the conventional chips, the chip having an easily detachable dovetail groove type cassette construction as shown in FIG. 6 is most easily used. However, with this construction, disadvantages have occurred in that a female die of a cassette stand 22 is apt to be unstable in strength under severe operating conditions, and both sides 29 and 29' of a male die and the female die are subjected to a taper machining, so that the accuracy is apt to fluctuate and the engagement position is apt to be not fixed. In addition, with respect to the construction, a blade having a cassette construction cannot be produced by casting, but must be produced by machining, so that the cost is increased.
The cassette construction of the blade, which is part of the present invention, has solved the problems described in the preceding page by changing the conventional dovetail groove type cassette, that is, an up and down engagement, to a side surface engagement, by means of a stand having a concave section along a direction perpendicular to the direction of blade rotation.
TEST EXAMPLE 1
Rotary substrates having diameters of 40, 60, 72, 80 and 100 inches (about 100 to 254 cm) and thicknesses of 5.0 to 7.0 and 6.59 to 9.0 mm, the substrates having 24 first semicircular slits and 12 second semicircular slits having a width of 0.2 mm formed thereon the slits are filled with fillers comprising low-viscosity flexibility-adjustable epoxy molding resins as a main ingredient of 40 or more % by weight, a hardener of 55 or less % by weight and a heat resistant, pressure resistant and shake-proof sealing agent of 10 to 15% by weight, which are subsequently set, were produced and tested with regard to sound damping effect. The results are shown in Table 1.
In addition, a measuring distance was set at 1 m in a low-noise room and the A scale of NA-09 manufactured by Rione, Ltd. was used for the measurement.
TABLE 1______________________________________ Resin- Rotation Usual Slitted filled frequencySize (inch) subst. subst. subst. r.p.m.______________________________________40 101 dB 101 dB 92 dB 55060 101 dB 102 dB 91 dB 35072 102 dB 102 dB 91 dB 30080 102 dB 102 dB 91 dB 300100 103 dB 104 dB 92 dB 230______________________________________
On the other hand, a rotary substrate having a size of 40 inches (about 100 cm), which is shown in Table 1, with four grooves of 1.5 mm width and 4 inches (about 10 cm) long, shown in the publication, formed from the vicinity of the base portion of the saw-toothed portion toward the center, and then filled with synthetic resin fillers having the same composition as the fillers, was produced and tested with regard to sound damping effect under the same conditions, with the result of 94 dB.
Next, the rotary blade according to the present invention using the slitted substrate is described with reference to FIGS. 3 (a) and (b).
FIG. 3 (a) shows a portion corresponding to the circumferential blade of the substrate shown in FIG. 1. Reference numeral 10 designates U letter-shaped grooves formed on the outer edge of the substrate 1 at regular intervals, which let ground powders go and serve as radiating portions. Chips 12, obtained by sintering diamond powders integrally with metals or by sintering tungsten carbide, are fixedly brazed and welded to whole stands 11 formed of the U letter-shaped grooves 10 to form the blade, or the blade is formed by the cassette construction.
According to the present invention, subsequently, the U letter-shaped grooves 10 are filled with fillers 6 having the same composition as the fillers used and described above. However, their composition may not always be the same as that of these fillers. The upper surface 13 of the fillers 6 is adapted to be within the groove and leave the groove room for depth between the preceding chip 12 and the subsequent chip 12.
FIG. 3 (b) shows a rotary blade provided with a key groove 14 in place of the U letter-shaped groove in the preferred embodiment shown in FIG. 3(a). As to the fillers 6, both are the same. Thus rotary blade is formed.
TEST EXAMPLE 2
24 first semicircular slits and 12 second semicircular slits were formed on a rotary substrate having a diameter of 40 inches and a thickness of 5.0 mm according to the TEST EXAMPLE, the respective slits being filled with fillers, chips being fixedly mounted on the whole stand portion on the circumference on the rotary substrate, and U letter-shaped grooves being filled with the fillers to produce a rotary blade. The resulting rotary blade was rotated at 550 r.p.m. without applying a grinding load with the result that the noise amounted to 92 dB as measured by the same method as in TEST EAXMPLE 1 for both the rotary substrate and the rotary blade.
The latter was ground with loading with the result that the noise amounted to 100 dB as measured in the same manner. It was found from this that the noise was reduced by about 10 dB or more in comparison with that of the conventional rotary substrate having the same shape and subjected to no sound damping measures.
TEST EXAMPLE 3
Referring to FIGS. 4 and 5, reference numeral 23 designates an outside portion of a substrate of a blade made of an iron plate and the like. A cassette stand 22 having a concave section is fixedly mounted on an end face of said outside portion 23 of the substrate by welding and the like. Reference numeral 21 designates cutting chips obtained by bonding super grinding material particles, such as diamond particles, with metals. A cassette stand 22 having a concave section is fixedly mounted on an inside end face of the cutting chips 21. Both cassette stands 22 are engaged in such a manner that the lower protrusion of the cassette stand 22, with the cutting chip 21 being fixed on the upper surface thereof, and which forms a concave section of the cassette stand 22, is attached to the concave portion the cassette stand 22 on the substrate 23. Either the upper or lower side forming the concave portion of each cassette stand 22 is made longer than the other, and the outside of the longer sides are fixed to the substrate and the chip, respectively.
An acute-angled taper 24 is formed in a sectional direction and a tapered surface 25 inclined in an opposite direction in correspondence to the acute-angled taper 24 is formed in a longitudinal direction on an inside of the longer side.
The shorter side 27 is engagedly put in the concave portion 26 of the other cassette stand, so that a plane 28 corresponding to the taper 24 and the tapered surface 25 meeting at right angles with the sectional direction is formed. A plurality of cassette stands 22 are fixedly mounted on the outside of the substrate 23 at intervals, as shown in FIGS. 4 and 5, but the tapered direction of the tapered surface 25 is the same.
The respective cassette stands 22 are fixedly mounted with a large number of cutting chips 21 are taperedly engaged with the substrate 23 in a direction shown by an arrow in FIG. 4 to be bonded integrally with the substrate 23.
It goes without saying that a direction of rotation or direction of advance of the substrate during the cutting is opposite to the direction shown by the arrow and the bonding strength is high. The cassette stand having the above described construction can be easily produced by shaving soft steel materials and the like, the powder metallurgy and the casting.
In addition, although the taper 24 in the sectional direction is formed on two concave sides and the tapered surface 25 in the direction meeting at right angles with the sectional direction is formed on merely one side, the contrary arrangement may be adopted and also the tapered surface 25 may be formed on two sides.
The comparison test results of the strength of the stands according to the preferred embodiments according to the present invention shown in FIGS. 4 and 5 and the conventional stand shown in FIG. 6 are shown in Table 2.
In the test of the rotary blade having a diameter of 80 inches, the stand was made of stainless steel (SUS 304) and W was set at 8 mm, H at 15 mm, L at 30 mm, T at 3 mm, and the taper of the tapered surface 25 was 1/25.
TABLE 2______________________________________ EX- AM- Conventional PLES example Note______________________________________Lateral bending 564 kgf 439 kgf The greaterstrength value is better.Force required for 255 kgf 230 kgf The greaterdrawing out the stand value isstriken in the direc- better.tion shown by an arrowin FIG. 4 by means of ahammerLength of the stand 2.22 mm 2.87 mm Thewithdrawn when a load smallerof 1.0 ton was applied value isin the same direction better.as in the abovedescribed itemLength of the stand 5.64 mm The stand Thewithdrawn when a load is disconnect- smallerof 2.5 tons was applied ed to make the value isin the same direction measurement better.as in the above describ- impossible.ed itemForce required for 664 kgf 452 kgf Thedrawing out the stand greaterstriken in the same valuedirection as in the isabove described item by better.a load of 1.0 ton______________________________________
As is obvious from the above described results, the present invention can not exhibit the effects thereof until the formed semicircular slits are filled with the fillers containing the synthetic resins and the sealing agents to integrate the semicircular slits with the substrate. In addition, it can be found that the rotary substrate according to the present invention exhibits a sufficient sound damping effect in comparison with the conventional rotary substrate in which the grooves extending toward the center are filled with the synthetic resins.
In addition, the rotary blade, in which the rotary substrate according to the present invention is used, the blade being fixedly mounted with stand portion formed on the circumference of the substrate, and the grooves between the blades being filled with the fillers, exhibits a sufficient sound damping effect in the above described manner and can improve the working environment where this kind of rotary blade is used.
Furthermore, the cassette construction of the blade is achieved by the side surface engagement, in which the concave insides of the cassette stands having a section intertwined, so that the construction is more stable in comparison with the conventional up and down engagement by means of the dovetail grooves, and can be easily produced with higher dimensional accuracy, thereby being capable of easy, stable use in the installation and detachment thereof.
With respect to the construction, not only is it easier in machining in comparison with the dovetail grooves, but it can also be produced by powder metallurgy using a press mold and casting using a casting mold, so that the cost of production can be reduced.
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A rotary blade has a rotary substrate with chips disposed about the outer edge of the substrate. The substrate further has two sets of semicircular slits. The first set of semicircular slits is disposed annularly about the rotary substrate on a circle coaxial with the center of rotation of the rotary blade. The semicircular slits open toward the center of rotation. The second set of semicircular slits are disposed on a circle inside of the circle of first slits. These slits open outwardly, thus blocking, at least partially, the first semicircular slits from the center of rotation. A filler material is filled into the semicircular slits, the slits thus providing a vibration damping effect. The chips may be attached to the outer edge of the rotary substrate by concave profiled cassette stands.
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The following is a continuation of U.S. patent application Ser. No. 09/051,178, filed Sep. 4, 1998 which is a 371 of PCT/IL96/00068 filed Jul. 29, 1996.
FIELD OF THE INVENTION
This invention relates to an improved vehicle parking method and systems, more particularly to a method and systems which do not require the use of parking meters or parking cards and which permit charging each user with the appropriate parking fees and crediting the appropriate parking authorities with said fees.
BACKGROUND OF THE INVENTION
Numerous parking systems have been described and are known in the art. Most of them, however, are relatively complicated and/or imperfect for various reasons, e.g. they may not assure that parking fees are debited to the appropriate persons or accredited to the appropriate parking authority, or they may make fraudulent use of the system possible, and so forth. Most parking systems require the use of parking meters, of more or less complicated structure and operation, and/or parking cards, the use of which may be complicated and inconvenient and which may require recharging or exchanging them, and so forth It would be desirable to eliminate these drawbacks and to provide a system which is simple, economical, easy to operate, and foolproof.
WO 93/20539 describes a system in which a unique alphanumeric code is assigned to each parking space and a vehicle is also assigned a unique alphanumeric code. When the vehicle has been parked in the parking space, the driver dials on a telephone the code of that parking space, the vehicle code and the personal or payment responsibility code. This code combination is sent via a transmitter and a relay station to a database, and the information concerning the parking space, the vehicle using it and the person responsible for paying the parking fee are registered. When the driver collects the vehicle from the parking space, he or she sends again the aforesaid information to said database over the vehicle telephone, and the database records that the parking period has been terminated. In this way the parking cost is debited by an appropriate authority or company.
This system, however, is defective in several ways. Firstly, it is extremely difficult to detect illegal parking, since this require acquiring a graphic picture of the parking areas supervised and checking with the aid of a computer whether the vehicle's code have been registered in the data base. Since there is no control of the information which the user sends via the telephone, the difficulties involved in this data comparison make parking frauds easy. Further, there is no way to detect immediately whether a vehicle is parking overtime. Such detection requires registering the plate numbers of all the parked vehicles and asking a central computer to check whether the driver of any of them may not have falsely indicated that the vehicle has left the parking space. This is certainly impractical and inefficient. With this technique it is possible to request and terminate the parking from outside the car, which is highly undesirable.
It is a purpose of this application to provide a parking method and apparatus that are simple, easy to use, economical and foolproof.
It is another purpose of this invention to provide a parking method and apparatus which do not require the use of parking meters or parking cards.
It is a further purpose of this invention to provide a parking method and apparatus which permit easy supervision of the parking location and immediate identification of the illegally parked vehicles.
It is a still further purpose to provide a parking method and apparatus which exclude all possible abuses or frauds on the part of the users.
It is a still further purpose to provide a parking method and apparatus that are very attractive and convenient both to users and to parking authorities.
It is a still further purpose to provide a parking method and apparatus which can be supervised easily and efficiently.
It is a still further purpose to provide a parking method and apparatus which render the allocation and distribution of the parking fees both simple and extremely accurate.
It is a still further purpose to provide a parking method and apparatus which permit the public agency, which exercises its authority over the parking zones, e.g. the city administration, to decide the parking time and other parking conditions according to zones.
It is a still further purpose to provide a parking method and apparatus which prevent damaging of parking apparatus, due to vandalism or other reasons
It is a still further purpose to provide a parking method and apparatus which prevent the scattering of refuse, such as used parking cards, in or in the vicinity of parking zones.
It is a still further purpose to provide a parking method and apparatus which do not require recharging of parking meters or exchange of parking cards.
It is a still further purpose to provide an integrated vehicle location system and parking network.
Other purposes and advantages of the invention will appear as the description proceeds.
SUMMARY OF THE INVENTION
The following nomenclature, used in this specification and claims, should be clearly defined for a complete understanding of the invention. Let us consider a public agency, such as a city, province, county or region administration which exercises its authority over a given territory. Such agency will be called “the public authority” or “the authority”—briefly, “the PA”. The territory will comprise, in general, a plurality of parking zones and the parking fees and fines, if any, will in the end be collected by the authority, which will also take any steps required to enforce the traffic laws and apply any penalties for their violation, which steps, however, are outside the scope of the parking method according to the invention. The PA will also establish the parking fees and other parking conditions and limitations.
In each territory, controlled by a public authority, or in one or more parking zones contained therein, one or, generally, a plurality of agencies will be authorized to operate the parking method according to the invention. Such agencies will be called “operating agencies” briefly, “OA”s. The territory or the plurality of parking zones in which an OA operates will be called “the territory” of that OA. The territories of different OA's may overlap, viz. a plurality of OA's may operate in the same parking zone or zones. The array of apparatus and devices for carrying out the parking method of the invention in any given territory of an OA will be considered and called “a parking network”. In general, therefore, there will be a parking network for each OA; but if an OA should operate in several separate territories, there will be several parking networks operated by said OA. The parking network, if there is only one; or the parking networks, if there is a plurality of them, constitute the apparatus or system according to the invention. The OA's generally, though not necessarily, are companies operating systems or networks of devices that can receive and transmit radio signals or messages, which devices will be collectively designated as transmitter-responder devices (hereinafter “TRD”). Examples of TRD are cellular phones, message recorders, pagers, private alarms, vehicle location units, and the like. As is well known, a plurality of such companies usually operate in the same territory.
Each person that is interested of making use of a parking network, or, as may be said, of entering a parking network, will be called hereinafter a “subscriber”. The subscriber need not necessarily be the driver or owner of a vehicle that will be parked according to the method of the invention. The person who actually parks the vehicle will be called hereinafter the “driver”. It is one of the advantages of the parking method according to the invention that it is irrelevant whether the driver is also the subscriber: the OA recognizes only the subscriber and attributes to it any communication it receives.
Each parking network according to the invention comprises, generally, a central computer, or, possibly, a number of central computers, operated by the OA, and, for each subscriber, in combination with a TRD, e.g. but not exclusively a cellular telephone, it comprises a complementary box, which can be coupled to said TRD, and only to it, and permits said TRD to communicate with said central computer. Each central computer is assigned a numerical address—hereinafter “the computer's nominal number”—which is public and known to all subscribers, but the computer will not accept any TRD communication unless the nominal number is dialed together with a numerical code stored in the memory of the complementary box (hereinafter also called “the integrating code”). The nominal number may include the designation of the parking zone and any other relevant information, in order to simplify the connection with the OA. The combination of the nominal number and the integrating code will be called “the computer's address”. The TRD identifies the subscriber for the purpose of charging him with parking fees, either through the TRD number, which is recorded by the central computer when parking is requested through the TRD, or through another code of any kind which can be transmitted by the TRD or associated with it. If the computer's line is open when the TRD dials the computer's address, the parking procedure, hereinafter described, will take place immediately. If said line is busy, the computer will so signal, and the delayed parking procedure, hereinafter described, will take place.
During the parking procedure, or at least at its beginning, the complementary box is intended to be coupled with the TRD. Said box is provided with display means, visible from outside the vehicle to a parking supervisor, for signaling authorized parking and the expiration of the allowed parking time, and other pertinent information, if any. If the complementary box has not been coupled with the TRD, the parking procedure cannot be carried out and no parking can be authorized, and said box indicates this by failing to signal that it is activated. The same is true if, for any other reason, the parking is not authorized by the central computer. When the authorized parking period has ended, the complementary box display means cease to indicate legal parking and indicates overtime parking. This is preferably achieved by providing said box with timing means, which registers the allowed parking time and measures the actual, elapsed 'parking time. In all cases in which the vehicle is not legally parked, information as to this fact can be transmitted to PA, as part of the supervising procedure, hereinafter described.
The term “coupling” is herein usually intended to indicate a physical coupling between the TRD and the complementary box, but it should be well understood that it may also refer to a coupling realized by radiation, e.g., electromagnetic waves.
Preferably, said complementary box comprises identification marks or indices, e.g. numerical identification means such as a bar code or the like, which can be scanned and registered from outside the vehicle, generally through the windshield. Said identification marks correspond to the TRD identification number, so that they also identify the subscriber. The absence of the complementary box renders the parking illegitimate.
It should be noted that, although this has not been illustrated, the complementary box need not be in a single piece, but may be constituted, for example, by two components, one of which may be a standard or universal one mounted by the car manufacturer, while the other one, provided and coupled to it when requested by a subscriber, will be adapted to the particular TRD used by the subscriber.
According to an embodiment of the invention, the complementary box includes:
a microcontroller or CPU which controls the operations of the box;
memory means for storing numerical addresses or “nominal numbers” of central computers that are part of the parking system and integrating codes;
means for storing and transmitting to said microcontroller identification numbers or marks, which correspond to the TRD identification number;
timer means for timing the duration of the parking;
a display;
driver means for communicating to the display the signals required for carrying out the supervision steps hereinbefore defined;
parallel/serial input/output means;
buffer means for transmitting information to the IRD and buffer means for receiving information from the TRD;
power supply backup means for connecting to a main power supply; and general bus means for establishing the required connections between all the aforesaid components.
A particular embodiment of such a complementary box will be described hereinafter.
Preferably, each parking network according to the invention additionally comprises a number of parking control devices, for use by parking supervisors, each of which comprises scanning means for reading the identification marks and the display signs of the complementary boxes, validation means, memory means for registering the information obtained from the scanning and any other pertinent information, and coupling means for coupling the control device to a terminal or computer or other information receiving device belonging to the PA.
The invention further provides a parking apparatus, comprising a plurality of networks as hereinbefore described.
The method of controlling vehicle parking and charging parking fees to the user, according to the invention, comprises therefore the steps of:
1. providing at least one central computer;
2. providing, for each subscriber, at least one transmitter-responder device and a complementary box, exclusively coupled the one to the other and correspondingly identified, the complementary box having display means for visually indicating its activation and the nonexpiration or expiration of the allowed parking time, and other pertinent information, if any;
3. once the vehicle has been parked, coupling said TRD to said complementary box, unless they were already so coupled;
4. controlling the specific parking location, its code and any other necessary parameters, if any, associated with it (said code and parameters being derived from a sign placed at the parking zone or being known to the user by other means);
5. dialing the central computer's nominal number, integrated with a code stored in the memory of the complementary box, to constitute the computer's address, and further, dialing the said parking zone's code and necessary parameters;
6. if the connection of the TRD with the central computer is effected, carrying out the following steps:
I. sending from the central computer to the TRD a parking authorization, the allowed parking time, and any other pertinent data, if any, thereby completing the parking procedure;
II. if the parking procedure has been completed, activating in the complementary box display a sign indicating legitimate parking and the parking zone;
III. downcounting, by means of a timer comprised in the complementary box, the actual parking time, viz. continuously counting the time that has passed and subtracting it from the allowed or maximum parking time;
7. if the connection of the TRD with the central computer is not effected, carrying out the following steps:
A. storing in the central computer's memory the data dialed by the TRD, placing the TRD in a waiting list and sending to the TRD a signal indicating that step A has been carried out;
B. activating, in the complementary box display, a sign indicating legitimate parking and the parking zone and beginning to downcount, by means of a timer comprised in the complementary box, the actual parking time;
C. when the connection of the TRD with the central computer has been effected, continuing the countdown of the actual parking time;
8. if the vehicle leaves the parking space before the end of the allowed parking time, signaling this fact from the TRD to the central computer, stopping the downcounting of the parking time and deactivating the complementary box display;
9. if, at the end of the allowed parking time the TRD has not signaled that the vehicle has left the parking space, deactivating in the complementary box display the sign indicating legitimate parking and activating a sign indicating overtime parking.
10. communicating from the central computer to the PA the subscriber's number, the parking location, the actual parking time, and other data, if any, required for the PA to collect the parking fees from the subscriber.
The parking fees could also be collected by the OA, based on the same data, and transferred accordingly to the PA.
If the allowed parking time elapses before the parking has. ended, the sign indicating legitimate parking in the complementary box display is deactivated and a sign indicating overtime parking is activated.
In carrying out the aforesaid parking method, it may occur that the connection of the TRD with the central computer is not effected and cannot be effected within an acceptably short time, because of a failure in the central computer or a breakdown of communication for any reason. In this case, means are preferably provided in the complementary box for signaling to the driver the impossibility of establishing communication, or it may be that such means are not provided or do not operate, but the driver becomes aware of an excessively long delay in establishing communication with the central computer. To account for such occurrences, in an embodiment of the invention, buffer memory means, activatable by the driver, are provided in the complementary box for registering the same operations that would have occurred had the normal parking operations been carried out. Specifically, the complementary box is programmed to register in the buffer memory an assumed parking authorization, an assumed allowed parking time, and any other assumed, pertinent data that may be required. The assumed allowed parking time and other data are determined by the parking location's code and by any other parameters associated with it, as in any parking. The sign indicating legitimate parking is actuated and the countdown is carried out. At the end of the parking, said sign is deactivated and the time is registered in the buffer memory. The driver may then leave the parking space, and, if appropriate, take the TRD with him. Thereafter, when a parking authorization is requested for a first time, or prior to that. at any time selected by the driver, the contents of the buffer memory are transmitted to the central computer. The central computer verifies that the registered parking procedure was correct, viz. that it would have transmitted to the TRD, if communication had been established when the parking actually occurred, the same data that are registered in the buffer memory, including the parking authorization, the allowed parking time, and any other pertinent data. If it is verified that the registered parking operations are correct, the central computer communicates to the PA the subscriber's number, the parking location, the actual parking time, and other data, if any, required for the PA to collect the parking fees from the subscriber, as it would have done as a result of normal parking operations; and then communicates to the TRD the authorization to resume normal operation. Until said authorization has been received, the complementary box does not allow any other parking to be carried out; and if it is refused, or has not been received within a given, predetermined time, it displays a signal indicating illegal parking. The central computer also registers an illegal parking, for all relevant purposes.
In addition to the steps of the parking method, set forth hereinbefore, the following supervision steps are a preferred part of the invention:
a—providing the supervisors of parking locations with control devices for validating the complementary boxes and for scanning and registering from outside the vehicles their identification codes;
b—registering, for each such identification code, the fact of legitimate or illegitimate parking and, optionally, the reason of this latter (e.g. inactivation of the complementary box or overtime parking) and any other pertinent data:
c—preferably, periodically, e.g. at the end of the supervisor's shift, transmitting to the PA the data contained in the memory of said supervisor's control device.
According to an embodiment of the invention, a VLU is used as TRD. Vehicle location units are apparatus that are well known in the art and are widely used for various purposes. Among such purposes are: locating stolen vehicles, for which purpose the VLU is activated if the vehicle is stolen; signaling the position of a vehicle in case of the vehicle's failure or in other emergency situations; and monitoring the position of various vehicles constituting a fleet, e.g. of transport trucks or public vehicles of any kind.
The VLU is part of a system which includes a control center, a plurality of fixed stations, having transmitting and receiving antennae, and the VLU apparatus itself. In a type of VLU systems, the VLU apparatus, carried by the vehicle, holds an identifying address code. The control center transmits a modulated signal, viz. a referencing signal, to the vehicle to be located, via the fixed stations. The VLU receives the signal and compares it to its identifying address. If it corresponds to it, the VLU sends an answer signal. The answer signal is received by the fixed stations. and is transmitted to the control center, which compares the information received from the fixed stations, in order to determine, e.g., the distance of the vehicle from each one of said stations and to compute therefrom the location of the vehicle. A VLU of this kind is described in UK patent application 2234140A.
Alternatively, the VLU may transmit to the fixed stations, once it has been activated by the driver or automatically (as in case of theft) a signal comprising an identifying code of its own, and the fixed stations and the control center will operate as set forth above.
Now, according to said embodiment of the invention, the vehicle parking system comprises, as TRD, a vehicle location unit. Additionally, however, the vehicle that is part of the parking system comprises means for placing the VLU in communication with the central computer or with a central computer of the parking system. These means, as well as other elements hereinbefore mentioned, which are not part of a normal VLU, should be considered as constituting the complementary box according to the invention.
If the VLU is intended to be used only for emergency situations, it will not normally transmit a signal, and the aforesaid complementary means will be activated by the driver when he starts parking and deactivated when the parking ceases. When the signal of the VLU, which will contain a vehicle identifying code and may contain the identification of the parking place and other pertinent data, is received by the central computer, this will operate to monitor the parking, determine its duration, and transmit to the complementary box the signals required for carrying out the supervision procedure.
However, it may be that the VLU is to operate continuously for a longer or shorter length of time while the vehicle is in motion. This may occur if the VLU system is used to track the vehicle at all times, so that its position may be always known to a control center; of it the driver actuates the VLU when he intends to seek a parking position or when the vehicle approaches such a position. In such cases, during the time in which the VLU is operated, the central computer will constantly know the position of the vehicle and will not require any activating signal when parking begins, because whenever the vehicle stops moving, it will compare the location of the vehicle to the parking locations which it controls, and if it is one of said parking locations, will start the 'parking procedure. It is clear that in this case the central computer must receive from the vehicle location control center the information relative to the position of the vehicle. Therefore, said central computer and said control center will be connected by information exchange means, which will be activated when the VLU starts operating, by the same signal which activates the vehicle location system.
In the previously mentioned case, viz. if the VLU is activated by the driver only for purposes of starting a parking procedure and only at the moment of parking, the same operational phases may take place, viz. the signal which starts the operation of the VLU will also cause the central computer to be placed in information exchange connection with the vehicle location control center; however, alternatively, the driver may communicate to the central computer a parking code, containing identification of the parking zone, as herein described, and in this case there will be no need for exchange of information between the vehicle location system control center and the central computer.
Consequently, this invention comprises a method of controlling vehicle parking and charging parking fees to the user, which comprises the steps of:
1. providing at least one central computer;
2. providing a vehicle location system, comprising a control center, a number of fixed stations and a VLU for each subscriber;
3. signaling to said central computer, at any desired time, a request that the vehicle location be monitored for parking control purposes;
4. when said signal is sent, sending from said central computer to said control center a request for vehicle location data;
5. when said request for vehicle location data has been sent, sending from said control center to said central computer the requested data;
6. monitoring the vehicle position, based on said vehicle location data, and determining therefrom when and where the vehicle has stopped;
7. comparing the location at which the vehicle has stopped with a list of parking locations controlled by said central computer, and, if said location at which the vehicle has stopped is one of them, registering the beginning of a parking;
8. activating a sign visible from outside the vehicle indicating legitimate parking;
9. counting the actual parking time;
10. when the vehicle begins to change its location, registering the end of the parking;
11. communicating from the central computer to the PA the subscriber's number, the parking location, the actual parking time, and other data, if any, required for the PA to collect the parking fees from the subscriber.
Once the central computer has identified the parking location, it will know whether there is a maximum parking time or other limitations in that location and will send to the VLU or to the display, if this is provided with autonomous receiving means, a signal embodying said limitations, and any violation thereof will be recognized by parking supervisors upon checking the display. In particular, if the maximum parking time has elapsed and the central computer has not registered that the vehicle has moved and therefore has not sent to the VLU or to the display a signal that the parking has ended, the display will indicate illegal parking.
In an embodiment of the invention wherein a VLU is used as TRD, the complementary box may be provided with buffer memory means for registering assumed parking operations, if communication with the central computer cannot be established, as hereinbefore described with reference to a generic TRD. When the data registered in the buffer memory are sent to the central computer, this latter will check the correctness of said data, obtaining from the control center of the vehicle location system the location of the vehicle as it was at the time the data were registered. If the control center is normally unable to supply retroactive location data, means may be provided for the VLU to request that it register the vehicle location at the relevant time, so as to be able to communicate it to the central computer when this latter requests it, or means my be provided for the driver to request that the control center communicate said location to the VLU, which can then register it in the buffer memory of the complementary box.
The invention further comprises an integrated vehicle location system and parking network, which comprises;
a—the components of a vehicle location system, viz. at least a control center, a number, e.g. three, of fixed stations and a VLU for each subscriber; and
b—the components of a parking network, comprising at least one central computer, and, for each subscriber, in combination with said VLU, means for permitting said VLU to communicate with said central computer.
According to one aspect of the invention, said integrated vehicle location system and parking network further comprises means for exchanging information between said vehicle location system control center and said parking network central computer, e.g. means in said computer for requesting location data from said control center and means in said control center for sending location data to said central computer.
Preferably, said integrated vehicle location system and parking network further comprises accessory means and components, such as: display means associated with the VLU, visible from outside the vehicle, for signaling authorized parking and the expiration of the allowed parking time, and any other pertinent information;
timing means, which registers the allowed parking time and measures the actual, elapsed parking time;
control means for parking supervisors and any other means required for carrying out the parking supervision steps.
As noted hereinbefore, said means for permitting said VLU to communicate with said central computer, said display means and said timing means, when present, and any other elements not included in conventional VLU's. should be considered as constituting the complementary box according to the invention, although they might in fact not be separate elements combined with a conventional VLU, but integral elements of a VLU modified to permit or improve its use as the TRD of a parking system and device. Their provision is, in any case, within the scope of this invention.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is a schematic illustration of the parking system according to an embodiment of the invention;
FIG. 2 is a schematic perspective view from inside a vehicle of a portable telephone applied to a complementary box;
FIG. 3 is a schematic view from the front of a complementary box as seen from the outside of the vehicle;
FIG. 4 is a block diagram of an embodiment of a complementary box;
FIG. 5 is a schematic illustration of a control device;
FIG. 6 is a block diagram of a complementary box according to another embodiment of the invention; and
FIG. 7 is a block diagram illustrating a parking system in which a VLU is used as a TRD.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference now to FIG. 1, each parking network according to the invention comprises at least one central computer 10 , located at a suitable location, generally remote from the parking zones. For each subscriber to the network, this latter comprises at least one TRD. In this particular embodiment, for purposes of illustration, the TRD is generally indicated at 11 as a cellular telephone, but this should not be construed as a limitation, as any transmitter-responder device could be used in place of cellular telephone 11 . The TRD is mechanically supported by any convenient support member, such as e.g. commonly provided in cars for supporting cellular telephones and the like, indicated at 18 (FIG. 2 ). The parking system also comprises, for each subscriber, at least one complementary box, generally indicated at 12 . Telephone 11 and complementary box 12 are shown in the drawing as operatively connected at 13 , for establishing the desired connection between their circuits, when the two devices are coupled. The operative connection may be of any suitable kind, and may e.g. comprise electrical cable means and a junction box, and requires no further description, as it may easily be provided by skilled persons. Power means are preferably provided for feeding electrical power to the complementary box. These means may include the battery of the car in which the box is mounted and an electrical connection between said battery and the box. Autonomous power means, however, could be provided for the box. The TRD, generally, has its own power means, such as batteries, but it may be connected, when in use according to the invention, to the car battery.
The complementary box 12 comprises a display 19 , shown in the drawing as separate, but actually forming the front of the box 12 , consisting for example of two lights 14 and 15 (FIG. 3) of different color, say red and green, and an identification code, say a numerical code such as a bar code or the like, that can be scanned and registered from the outside, indicated at 16 (FIG. 3 ). The device can also display other information, such as the end of the allowed parking time, etc, as schematically indicated in the display 17 (FIG. 2 ). The complementary box permits the telephone 11 to communicate with the central computer 10 via antenna 22 , by communicating to it the appropriate integrating code, to form, together with the computer's nominal number, the computer's address. The telephone keys, generally indicated at 20 , permit to dial and also to transmit other coded information to the central computer 10 . 21 and 22 designate antennae of the complementary box and of the central computer, respectively. In lieu of using an antenna which is part of the complementary box, the TRD's antenna could be used. 25 is a control box, to be described hereinafter. 26 is the computer of the PA.
FIG. 2 shows in schematic perspective an example of telephone 11 and a complementary box 12 , seen from the interior of the vehicle, while FIG. 3 schematically shows the display 17 of the complementary box 12 , as seen through the windshield.
FIG. 4 is a block diagram of a complementary box 12 according to an embodiment of the invention. 30 indicates the CPU of said box. 31 indicates the part of the CPU which recognizes that the appropriate TRD has been connected to the box and provides the validation or consent for the box to carry out its functions. The CPU receives information from the TRD at 32 and sends information to it at 33 . 34 is a unit by means of which the validation procedure to be described, for determining that the box 12 is an authentic one, is carried out. 35 is the timing circuitry which effects the countdown of the actual parking time. The complementary box receives power from any convenient source, e.g. the car battery, said power input being indicated by arrow 36
Each parking network according to the invention is used in the following manner. When the vehicle is parked and the telephone 11 (or other TRD) is coupled with the complementary box 12 , the telephone 11 can connect with the central computer 10 by dialing its nominal number. If the telephone is not coupled with the complementary box, the dialing of said number will produce no results, and the telephone will not be connected with the central computer. If the telephone is coupled with the complementary box and said nominal number is dialed, the complementary box integrates it, as has been said, by an integrating code stored in the complementary box memory, to form the computer's address and permits it to receive the communication from the TRD. The driver also dials (desirably by means of the usual keys, though other special keys could be provided) a code number or code numbers identifying the parking zone and all the relevant parameters relating to it. The parking zone may be incorporated in the nominal number.
If the central computer's line is open and connection is made between it and the TRD, the computer will signal to this latter its acceptance of the parking request and any other useful information—unless that particular telephone is disqualified for any reason (either connected to the phone itself, e.g. failure to pay earlier phone bills, or communicated by the PA, e.g. because it is not associated with a solvent charging account, or because parking in that particular location is not allowed at that time). It will also communicate the maximum allowable parking time and any other pertinent information. The central computer's reply will cause the complementary box to activate the signal which indicates legal parking and to begin downcounting the parking time, viz. continuously measuring the time passed and subtracting it from the allowed parking time. This will complete the parking procedure.
If, when the driver dials the computer, the line is busy, the computer will so advise, place the subscriber in a waiting list, and activate the legal parking time. The parking procedure will be completed when the line becomes free, even if the telephone has been removed meanwhile from the complementary box.
Once the parking procedure has been completed, or the subscriber has been put on a waiting list, the TRD can be removed from the complementary box and used in a normal way by the driver; but it cannot communicate with a central computer and request parking anywhere or extension of the allowed parking time, until it is coupled once again to the complementary box.
When the driver leaves the parking space, he calls once again the central computer and communicates the end of parking. The central computer deactivates the complementary box and registers the time elapsed in parking. Based on these data, the OA collects the parking fees, or more precisely, debits the subscriber's account with said fees, which are the paid to the PA. Alternatively, said data may be transmitted to the. PA, which, in that case, directly debits the subscriber's account with the corresponding fee.
The parking supervisor passes periodically among the parked vehicles with a control device which includes scanning and memory, preferably random-access memory, means. FIG. 5 schematically illustrates such a device, generally indicated at 40 . It is provided with an antenna 41 , keys 42 and a display 43 . It is further provided with a bar code reader or other device for reading the identification marks of the complementary box 12 , indicated at 44 . 45 indicates means for coupling the device to the PA computer or to a terminal leading to it.
As the supervisor passes near a vehicle or stops in front of it, a validation procedure is firstly carried out, to assure that the complementary box of the vehicle is an authentic, and not a counterfeit or otherwise illegitimate, one. There are several variants of the way in which such a procedure can be carried out. One of them is for the supervisor to send to the box, by infrared or ultrasound or other radiation, a message to which the box responds, according to a program stored in its memory, by showing a coded response in its display. To render circumvention of this procedure more difficult, a number of programs may be stored in each box memory and the supervisor may choose one of them in a random manner. Or the supervisor may change, in a random or other manner, the message he sends to the box. Another validation procedure requires that the box send, by infrared or ultrasound or other radiation, continuously or at short intervals, a message the authenticity of which can be checked by the control device.
Once the validation has given a positive result, the scanning means of the control device scan the identification marks of the complementary box (as has been said, a bar code or any other convenient identification means, either numerical or other) and this identification is registered in the control device memory. If the supervisor sees that a vehicle is illegally parked, because the complementary box is inactivated or signals overtime parking, or for any other reason, he registers this fact in the control device by an appropriate code identifng the particular parking violation. If the complementary box is missing, he may register the plate number of the vehicle. If the complementary box indicates legal parking, he may also enter this fact in the memory of the control device. The communication between the control device and the complementary box, for carrying out the above operations, is schematically indicated at 46 in FIG. 1 .
At the end of a specified period, usually at the end of the supervisor's shift or working day, or at any other convenient time, the supervisor will bring his control device to a location designated by the PA, and there he will couple it to a computer or a terminal operated by the PA and transfer to it the content of his control device's memory. The PA may react in any suitable way—which is not a part of the parking method of the invention—to any illegal parking registered by the control device.
The parking networks according to the invention, as has been seen, are based on components which are available in the art or which it is easily within the capability of skilled persons to procure or to design. A central element of each network is constituted by the coupling of the TRD and the complementary box. As has been said, central computers will not accept a communication from any TRD which dials its nominal number, unless this is integrated by a specific code that can be sent only by a complementary box A block diagram of a complementary box, according to an embodiment of the invention, is shown in FIG. 5, merely for illustration purposes.
Each complementary box has a CPU, which comprises memory means, preferably a ROM. When the subscriber purchases a complementary box, the device manufacturer or seller will register in its memory the number of the TRD, e.g. cellular telephone, which the subscriber intends to use. This can be done in many ways, for instance by coupling the TRD to the complementary box and actuating it, or in any other manner easily understood by skilled persons. Thereafter the complementary box will refuse to communicate in any way with a TRD having a different number, that is, its circuitry will remain inactive until a consent or validation is given by the CPU, which consent is dependent on its having received from a TRD, coupled to the complementary box, the TRD number registered in the box memory. Once the consent has been given, the complementary box will still remain inert as long as the TRD coupled to it does not dial the nominal number of a central computer, and when it dials it, the box will integrate said number with the code stored in its memory. Generally, each subscriber will dial one and only one computer, since each subscriber generally subscribes to a single parking network, as hereinbefore defined, and each such network generally includes one and only one central computer; and therefore only one such code will be stored in the box's memory. However, if a subscriber may have to dial more than one central computer—as might occur if he subscribes to more than one parking network (e.g., if he uses two or more cellular phones belonging to different cellular phone networks) or if the parking network to which he subscribes covers such a wide territory that more than one central computer is required to cover it—the box's memory will store a list of the nominal numbers of such central computers and the corresponding integrating codes. The subscriber will know what central computer is to be contacted in each case, or he will obtain this information from a sign posted at the parking location.
Also, the complementary box has in it a timer which will be set to the allowed parking time and will count the actual parking time. As has been said, the expiration of the allowed time will cause the legal parking sign to be switched off and the illegal parking sign to be switched on. In many cases the legal parking sign will be a green light and the illegal parking sign will be a red light, but different display means can be provided without difficulty.
The supervisor's control device comprises, as has been said, scanning and memory means, means for carrying out the validation procedure, and means for accessing the computer of the PA. Such a device can easily be designed and made by persons skilled in the art.
Referring now the block diagram of FIG. 6, it is assumed that the TRD is a cellular telephone, but it should be clear that it can be any other TRD without requiring any change in the complementary box and therefore this latter could be used in any embodiment of the invention. The complementary box includes an inner circuit generally indicated at 50 and a display, generally indicated at 51 . Circuit 50 and display 51 may be embodied in a single physical structure or box, or may be part of separate structures or boxes functionally connected.
The circuit 50 comprises a general bus 60 for connecting the several functional components together. The diagram indicates particular types of the several components which are available on the market, and can be used to construct a specific embodiment of the invention. However it will be obvious that other components, having similar functions, can be used in place of those identified in FIG. 6 . Said components, therefore, include a microcontroller or CPU 61 , and a non-volatile memory 62 . It further comprises an external identification unit 63 , which identifies the TRD (in this example, the cellular telephone) and an internal identification unit 64 , which identifies the device (complementary box) itself A timer 65 , is further provided for timing the parking. Buffers 66 and 67 are provided to provide buffers for transmission and reception of data between the complementary box and the server. telephone. Drivers 68 connect complementary inner circuit 50 to display 51 , which can receive infrared or other radiation signal at 70 , during the supervision procedure. Power is received by circuit 50 at 71 from a power supply through a power supply backup 72 , which assures that the data stored in the device will not be canceled if the device is cut off from its normal power source. Finally, numneral 73 indicates a parallel/serial input/output unit for sending and receiving data at 74 and 75 . These have the purpose of permitting the user to request and extract data from the device, for verification or other purpose. As hereinbefore stated, suitable components, for a particular embodiment of the inventions, are identified in FIG. 6, but others may be used by skilled persons.
FIG. 7 is a block diagram illustrating a parking system wherein VLU's are employed as TRD's.
In this embodiment of the invention, a vehicle (not shown in the block diagram) belonging to a subscriber to the parking system, has mounted therein a VLU 80 , which may be active at all times when the vehicle is operated, or may be activated by the driver at a chosen time during the vehicle's operation, in order that the vehicle be monitored over a considerable length of time or when the vehicle approaches the parking lot and the driver wishes to prepare for the parking procedure. The activation of the VLU causes a signal to be sent to the central computer 82 which controls the parking lot, and the signal comprises an identification code of the vehicle. The computer 82 then sends a signal to the vehicle location system control center 84 requesting the vehicle location data. Concurrently the VLU sends a normal vehicle location signal, which is received by fixed stations e.g. three stations 85 , 86 and 87 , which transmit data to the control center. The control center computes the location of the vehicle 80 and sends to computer 82 a signal comprising the location data, if they have been requested by said computer. When the signals received by the computer 82 indicate that the vehicle has stopped, the computer compares the coordinates received from the control center 84 to a list of parking lot coordinates contained in its memory, and if it finds that a vehicle has stopped at a parking lot, initiates the parking procedure as hereinbefore described. As a result, the display 89 , associated with the VLU and which may be considered part of the complementary box of the parking device, shows that the vehicle is properly parked.
The parking time is now counted. This is preferably done by the central computer, which will consider the parking as ended when the location data it continues to receive from said control center indicate that the vehicle has started moving. A timer, however, can be associated with the VLU, particularly for showing the time elapsed on the display. If such a timer is provided, a signal indicating the end of the parking could also be sent by the VLU to the central computer, but this is not necessary and may be undesirable. In any case, while the parking is in progress, the parking supervisor can see from the display 89 that the vehicle is properly parked and can derive from it and/or exchange with it all useful information, as detailed herein. At the end of the parking, the central computer registers the parking data.
The same operation as described in FIG. 7 can be effected if the driver activates the VLU only when he is in the parking lot. In that case he can send a signal to computer 82 , identifying the parking lot, and the intervention of fixed stations 85 to 87 and of the control center 84 is not required. However, alternatively, the system illustrated in FIG. 7 can still be used, in which case, when the driver enters the parking lot, he activates the VLU, the VLU sends a signal to the computer, the computer sends a signal to the control center, etc. as described with reference to FIG. 7 . In this case, the signal sent from the VLU to the computer is merely an activating signal and does not need to identify the parking lot, since this will be identified through the location of the vehicle.
In any embodiment of this invention, all the elements of the VLU that are required for its normal operation as part of a vehicle location system may be considered as the TRD of a parking device, while those elements that are part of or associated with the VLU, but are not so required, may be considered as constituting together a complementary box of a parking device.
As noted above, the coupling between the TRD and the complementary box does not necessarily require physical contact between them for initiating the parking procedure. The coupling may be accomplished by connecting the TRD and the complementary box by radiation, e.g., electromagnetic waves, although this has not been illustrated. The TRD and the complementary box may be provided with specific code to allow them communicate exclusively via specific wave frequency, so that the central computer will recognize that the TRD is actually coupled to the complementary box, said complementary box being therefore able to receive the updated data from said central computer. In this way, the subscriber may gain the advantage of prolonging the parking time without being forced to return back to the car. The communication between the various components of the system, required for carrying out the parking procedure, will be as described above, the TRD and the complementary box behaving as if they were coupled physically.
While embodiments of the device have been described for purposes of illustration, it will be apparent that the invention will be carried into practice with many modifications, variations and adaptations, without departing from its spirit or exceeding the scope of the claims.
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A vehicle parking network comprises a transmitter-responder device (TRD) for each subscriber and a complementary box which can be coupled to the TRD and only to it, and permits it to communicate with a central computer. The complementary box is provided with identification marks that can be scanned from the outside and includes a microcontroller, memory means and timing means. Once the vehicle is parked, the TRD is used to obtain from the computer a parking authorization and an allowed parking time. Then a legitimate parking sign is displayed and the parking time is down counted until the allowed time has been completed or until the vehicle leaves the parking space. If communication with the computer cannot be established, the complementary box carries out an assumed parking procedure, stores its data in a buffer memory, and later transmits them to the computer for verification and registration. The computer communicates the data of each parking to the Public Authority charged with collecting the parking fees. Examples of TRD's are cellular phones, message records, pagers, private alarms and vehicle location units (VLU). If a VLU is used, the central computer obtains vehicle location data from the control center of the vehicle location system, monitors the vehicle position, and carries out the parking procedure.
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The present application, U.S. Pat. application Ser. No. 11/026,721 is a continuation of U.S. Pat. application Ser. No. 10/788,146 now U.S. Pat. No. 6,839,505.
The present application also finds itself in the following family of related applications claiming priority to U.S. Pat. application Ser. No. 09/976,176, now U.S. Pat. No. 6,701,066; U.S. Pat. application Ser. No. 09/788,146, now U.S. Pat. No. 6,839,505; U.S. Pat. application Ser. No. 10/787,692; and U.S. Pat. application Ser. No. 11/026,721.
BACKGROUND OF THE INVENTION
The present invention relates in general to vapor delivery systems for deposition processes, and in particular to systems and methods for reliably delivering solid precursors to a deposition chamber.
Chemical vapor deposition (CVD) is a common process used in the manufacturing of films, coatings, and semiconductor devices. In a CVD process, a layer is formed on a substrate such as a semiconductor wafer by the reaction of vapor phase chemicals on or near the surface of the substrate. CVD processing is highly desirable in many applications due to it's relatively fast processing times and ability to form highly conformal layers on irregular shaped surfaces including deep contact openings.
CVD processes typically deliver one or more gaseous reactants to the surface of substrates positioned within a deposition chamber under temperature and pressure conditions favorable to the desired chemical reactions. As such, the types of layers that can be formed on a substrate using CVD techniques is limited by the types of reactants or precursors that can be delivered to the surface of the substrate.
Liquid precursors are commonly used in CVD processes due to the ease of their delivery to the deposition chamber. In typical liquid precursor systems, the liquid precursor is placed in a bubbler and heated sufficiently to transform the precursor to the vapor phase. A carrier gas typically either travels through the liquid precursor or passes over the bubbler at a controlled rate thus saturating the carrier gas with the precursor. The carrier gas then carries the liquid precursor to the surface of the substrate. Liquid precursors are commonly employed in CVD processes because the amount of liquid precursor can be precisely and consistently controlled.
The techniques developed for the delivery of liquid precursors cannot be used to reliably deliver solid precursors however. It is difficult to vaporize a solid precursor at a controlled rate such that reproducible flows are achieved. As a solid precursor sublimates, the shape and morphology of the remaining solid precursor changes. The changing volume of the solid precursor results in a continuously changing rate of vaporization. The changing rate of vaporization is notable particularly in thermally sensitive compounds. Additionally, an oversupply of vaporized solid precursor can result in condensation of the vapor back into a solid thus clogging vapor delivery lines and other monitoring equipment. Further, the use of a carrier gas is substantially ineffective as a means to implement rapid changes to the flow of the solid precursors.
Despite the difficulties in delivering solid precursors in CVD processes, there are many desirable precursor materials including for example, organometallic precursors, that are readily available in solid form. Further, many desirable precursor materials including organic and inorganic precursor materials may not be readily available in gas or liquid form. Also, solid precursors are particularly useful in the deposition of metal-based films, such as metal nitrides and metal silicides.
Therefore, there is a need in the art for a vapor delivery system for delivering solid precursors in a CVD process at a controllable rate.
SUMMARY OF THE INVENTION
This need is met by the present invention wherein systems and methods are provided for delivering solid precursors in deposition processes. A flow monitor is used to measure the flow of vaporized solid precursor material. The flow monitor is capable of measuring vapor flow that is maintained at a high temperature and low inlet and outlet pressure to avoid condensation of the precursor. The vapor flow measured by the flow monitor is fed back to a controller arranged to adjust the supply of vapor at the inlet of the flow monitor.
In accordance with one embodiment of the present invention, a solid precursor material is sublimated in a vaporization chamber by heating the solid precursor material with a fast response heater. As the vaporized solid precursor material is fed from the vaporization chamber into a deposition chamber, a flow monitor measures the vapor flow. The vapor flow measurements are input into a controller that communicates with the fast response heater to effect rapid changes to the temperature applied to the solid precursor material. As such, the temperature changes affect the rate at which the solid precursor sublimates, and thus the vapor flow is controlled.
In accordance with another embodiment of the present invention, a solid precursor material is sublimated in a vaporization chamber and fed into a deposition chamber. As the vaporized solid precursor material is fed into the deposition chamber, a flow monitor measures the vapor flow. The vapor flow measurements are input into a controller that communicates with a valve positioned upstream of the flow monitor to adjust the amount of excess vapor siphoned by the valve, and thus the vapor flow is controlled.
In accordance with another embodiment of the present invention, a solid precursor material is sublimated in a vaporization chamber by heating the solid precursor material with a fast response heater. As the vaporized solid precursor material is fed from the vaporization chamber into a deposition chamber, a flow monitor measures the vapor flow. The vapor flow measurements are input into a controller that communicates with the fast response heater to effect rapid changes to the temperature applied to the solid precursor material and/or the controller communicates with a valve positioned upstream of the flow monitor to adjust the amount of excess vapor siphoned by the valve, and thus the vapor flow is controlled.
Accordingly, it is an object of the present invention to provide systems and methods of delivering a solid precursor to a deposition process.
It is an object of the present invention to provide systems and methods to reliably measure the vapor flow of a solid precursor.
It is an object of the present invention to provide systems and methods to reliably and rapidly change the flow of vapor supplied to a deposition process.
Other objects of the present invention will be apparent in light of the description of the invention embodied herein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The following detailed description of the preferred 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 vapor delivery system for a deposition process according to one embodiment of the present invention;
FIG. 2 is a flow chart illustrating a simplified controller scheme;
FIG. 3 is a schematic illustration of the vapor delivery system of FIG. 1 , further illustrating multiple controller inputs and the use of a pressure regulator;
FIG. 4 is a flow chart illustrating a simplified controller scheme incorporating a check to determine whether vapor is within a pressure guard band;
FIG. 5 is a schematic illustration of the vapor delivery system of FIG. 1 , further illustrating an external pressure sensor positioned along the delivery line upstream of a flow monitor;
FIG. 6 is a schematic illustration of a vapor delivery system for deposition processing according to another embodiment of the present invention;
FIG. 7 is a schematic illustration of the vapor delivery system of FIG. 4 , further illustrating the use of a pressure regulator; and
FIG. 8 is a schematic illustration of a vapor delivery system for deposition processing according to another embodiment of the present invention.
DETAILED DESCRIPTION
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, and not by way of limitation, specific preferred embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention.
Referring to FIG. 1 , a vapor delivery system 100 for the controlled delivery of solid precursors is illustrated. A vaporization chamber 102 includes a housing 104 and a first surface 106 that is coupled to a heating device 108 . The heating device 108 regulates the temperature of the first surface 106 and includes a variable temperature control 110 to adjust the temperature that the heating device 108 supplies to the first surface 106 . The temperature control 110 is arranged to vary the temperature of the heating device 108 over a range of temperatures as more fully explained herein.
During deposition processing, a solid precursor material 112 is positioned on the first surface 106 of the vaporization chamber 102 , and the heating device 108 heats the first surface 106 to a temperature sufficient to transform the solid precursor material 112 to a vapor 114 . As such, at least a portion of the temperatures within the range of temperatures controllable by the temperature control 110 are sufficient to sublimate or otherwise transform the solid precursor material 112 to a vapor 114 .
The heating device 108 does not need to be in direct contact with the first surface 106 . Rather, it will be understood that any coupling can be used to transfer the energy generated by the heating device 108 to heat the first surface 106 . The exact relationship between the heating device 108 and the first surface 106 will depend upon such factors including the construction of the vaporization chamber 102 , the type of heating device 108 used, and the intended solid precursor material 112 . For example, the heating device 108 may comprise a fast response heater such as a thermoelectric heater that is based upon the thermoelectric (Peltier) effect. The temperature control 110 can be implemented as any device that adjusts the temperature output by the heating device 108 . For example, the temperature control 110 may comprise an analog switch, circuit, a PID temperature controller or other digital circuit.
As a solid precursor material 112 sublimates, the shape and morphology of the remaining solid precursor material 112 changes. The changing volume of the solid precursor results in a continuously changing rate of vaporization. As such, the heating device 108 is preferably capable of regulating the temperature of the first surface 106 over a wide range of temperatures, room temperature to 400 degrees Celsius for example. Further, the heating device 108 should be capable of rapid temperature change. For example, a change of 20-30 degrees within milliseconds is preferable. The present invention is in no way limited by the rate in which the heating device 108 can change temperatures, however, as explained more fully herein, results of controlling vapor flow may vary depending upon the ability of the heating device 108 to change temperature.
The vapor 114 travels out the vaporization chamber 102 and into a delivery line 116 . The delivery line 116 comprises any tubing or conduit suitable for routing the vapor 114 . A flow monitor 118 is positioned along the delivery line 116 in such a manner as to be able to measure the vapor flow therethrough. As illustrated, the flow monitor 118 is positioned inline with the delivery line 116 such that a first delivery line section 120 routes the vapor 114 from the vaporization chamber 102 to the flow monitor 118 , and a second delivery line section 122 routes the vapor 114 from the flow monitor 118 to a deposition chamber 124 .
The vapor 114 flows through the deposition chamber 124 and onto one or more substrates, wafers, or other surfaces 126 . Residual vapor is drawn from the deposition chamber 124 through the exhaust port 128 by the pump 130 . The deposition chamber 124 is also sometimes referred to as a process chamber, reactor chamber, or deposition reactor. It will be appreciated that the vapor delivery system 100 of the present invention can be configured to supply vaporized solid precursors to any deposition chamber 124 for material deposition performed using established CVD or any other deposition processes as are known in the art.
The flow monitor 118 comprises a device capable of accurately measuring the vapor flow therethrough. The flow monitor 118 must be capable of generating accurate flow measurements at both high temperatures and low inlet and outlet pressures with minimal and preferably no restriction to the vapor flow. The high temperatures and low pressures are required to maintain the solid precursor material 112 in the vapor phase. As illustrated, the flow monitor 118 comprises an inlet 132 , an outlet 134 , a flow sensor 136 , and associated electronics 140 . The flow monitor 118 may also optionally include therein, a flow restrictor 138 , a pressure sensor 142 , a temperature sensor 144 , or both. The electronics 140 provides the ability to output the measured flow, and optional temperature and pressure measurements. The electronics 140 may also perform calculations or processes required by the flow monitor 118 .
The flow monitor 118 may be implemented for example, as either an analog or digital mass flow controller. However, a digital mass flow controller based upon either pulsed gate flow or sonic nozzle technologies are preferred due to the accuracy and control afforded by such devices. It will be appreciated that the flow monitor 118 may require additional hardware depending upon its implementation. For example, a thermal mass flow controller gas stick may require additional components such as pressure transducers, filters, bypass valves, and in some cases, pressure regulators (not shown). Further, some mass flow controllers determine vapor flow based upon a measured pressure. As such, one pressure sensor and the appropriate electronics can output both the vapor flow and pressure. Accordingly, one physical sensor or device can embody one or more of the sensors schematically illustrated herein.
The flow monitor 118 is capable of controlling the flow rate into the deposition chamber 124 . By controlling the flow rate into the deposition chamber 124 , the deposition rate of the solid precursor material 112 onto the surface of the substrate 126 positioned within the deposition chamber 124 is controlled. The flow monitor 118 controls the flow rate of the vapor 114 into the deposition chamber 124 by choking the flow of vapor in the first delivery line section 120 to let the desired amount of flow through. This is accomplished for example, by closing the flow restrictor 138 within the flow monitor 118 . However, as the flow is choked off, the pressure upstream of the flow restrictor 138 increases. Should the pressure rise too much, condensation will occur as the vaporized solid precursor material 112 transforms back into the solid phase. If the solid precursor material 112 transforms from the vapor phase back to the solid phase, the flow monitor 118 and first delivery line section 120 can clog, jam, or otherwise suffer performance degradation.
To maintain the solid precursor material 112 in the vapor phase, a controller 146 is used to adjust the temperature of the heating device 108 to account for detected or expected changes in pressure. The controller 146 has a first input 148 coupled to the flow monitor 118 . The first input 148 receives as an input, the vapor flow measured by the flow monitor 118 . The controller 146 further includes a first output 150 coupled to the temperature control 110 of the heating device 108 . The first output 150 is arranged to adjust the temperature generated by the heating device 108 in such a manner to control the flow of vapor 114 through the vapor delivery system 100 . By reducing the flow of vapor 114 , the pressure in the first delivery line section 120 is also reduced.
It will be appreciated that the controller 146 can be implemented in a number of ways. For example, the controller 146 may be implemented as dedicated hardware, as a microprocessor based circuit, as a dedicated turnkey computer system, or a general-purpose computer running the appropriate software to implement the present invention.
Referring now to FIG. 2 , a controller scheme 200 is illustrated. The measured vapor flow is read in block 202 . The measured vapor flow is then compared to a desired vapor flow in block 204 . In decision block 206 , the measured vapor flow is tested to determine whether the measured vapor flow is at too low a rate for the given deposition process. If the measured flow rate is too low, the flow rate is increased in block 208 , and a new measurement is taken by feeding back control to block 202 . If the measured flow is not too low, the measured flow is tested to determine whether it is too high in block 210 . If the measured flow is too high, the flow rate is reduced or choked in block 212 and a new measurement is taken by feeding back control to block 202 . Otherwise, the flow rate is acceptable, and control is fed back to block 202 to take a new measurement. It will be understood that this flow chart is only representative of the possible implementations of the invention more fully described herein. Further, the desired flow may actually be represented as a range of acceptable flows.
Referring back to FIG. 1 with reference to FIG. 2 , for a given solid precursor material 112 , the controller 146 (such as a general purpose computer) has preprogrammed therein, a desired flow rate or range of acceptable flow rates to achieve a desired deposition layer. When the deposition process begins, the controller 146 reads the measured flow and compares the measured flow to the desired flow rate. If the measured vapor flow is too low, the controller 146 adjusts the temperature of the first surface 106 of the vaporization chamber 102 by sending a control signal to the temperature control 110 of the heating device 108 to affect the necessary adjustment, for example, to increase the temperature of the first surface 106 . If the measured flow exceeds the desired flow, the output of the controller 146 signals the temperature control 110 to reduce the temperature applied to the first surface 106 of the vaporization chamber 102 thus lowering the quantity of solid precursor material 112 that vaporizes and thus reduces the vapor flow. It will be appreciated that the amount of a particular adjustment will depend upon the type of solid precursor, the response time of the heating device 108 used, the reaction time of the flow monitor 118 to determine the vapor flow rate, and other factors. Further, the desired flow rate may have different values during various portions of the deposition process. The system continues to monitor the vapor flow through the flow monitor 118 and make adjustments as necessary until the deposition process is complete.
The vapor delivery system 100 optionally includes pressure regulation to assist in maintaining the solid precursor material 112 in the vapor phase. There are a number of ways to accomplish pressure regulation. According to one embodiment of the present invention, an inert gas is fed into the delivery line 116 as illustrated in FIG. 3 . The inert gas 152 is provided by a gas source 154 and is fed into the vaporization chamber 102 through a gas line 156 . A flow regulator 158 is provided to control the amount of inert gas 152 that enters the vaporization chamber 102 . The controller 146 optionally comprises a second output 160 that couples to the flow regulator to adjust the amount of inert gas 152 that is introduced during deposition processing.
It will be observed that any number of optional flow monitors 162 and valves 164 may be positioned inline with the gas line 156 before entering the inlet of the vaporization chamber 102 . Further, while schematically, the second output 160 of the controller 146 is illustrated as being coupled to the flow regulator 158 , it will be understood that other control schemes may be implemented. For example, if an optional flow monitor 162 , such as a digitally controlled mass flow controller is positioned inline with the gas line, the second output 160 of the controller 146 may couple to the mass flow controller to regulate the amount of inert gas 152 that enters the vaporization chamber 102 and delivery line 116 .
Additionally, depending upon the selection of solid precursor material 112 , an optional carrier gas 166 may be used to assist the vapor 114 in transmitting from the vaporization chamber 102 to the deposition chamber 124 . It will be appreciated that the carrier gas 166 is supplied by the carrier gas source 167 and may utilize a second gas line 168 , flow regulator 170 , flow monitor 172 , and other components as is known in the art. The carrier gas 166 may be fed into the vaporization chamber 102 using a second inlet (not shown), or alternatively, the carrier gas 166 may tie into the inert gas line 156 downstream from the inert gas flow regulator 158 .
If the flow monitor 118 includes the optional pressure sensor 142 and is capable of generating an output signal representing the measured pressure, this signal may be fed into the controller 146 as a second input 174 . Likewise, if the flow monitor 118 includes the optional temperature sensor 144 and is capable of generating an output signal representing the measured temperature, this signal may be fed into the controller 146 as a third input 176 .
The addition of measured pressure and temperature data allows for more sophisticated processing by the controller 146 . For example, the controller 146 contains predetermined data that provides the temperature and pressure conditions required to maintain a particular solid precursor in the vapor phase. This information may be stored for example, in the form of a formula or lookup table. Based upon given temperature conditions, a guard band, or range of acceptable pressures is determined. The guard band will vary depending upon the type of solid precursor being sublimated for deposition processing. The controller 146 can now monitor both the flow rate to ensure proper deposition processing, and make sure the pressure is maintained within the guard band to avoid condensation from forming in the flow monitor 118 and delivery line 116 .
Referring now to FIG. 4 , a controller scheme 300 including pressure guard band testing is illustrated. The measured vapor flow is read in block 302 . The measured vapor flow is then compared to a desired vapor flow in block 304 . In decision block 306 , the measured vapor flow is tested to determine whether the measured vapor flow is at too low a rate for the given deposition process. If the measured flow rate is too low, the flow rate is increased in block 308 , and a new measurement is taken by feeding back control to block 302 . If the measured flow is not too low, the measured flow is tested to determine whether it is too high in block 310 . If the measured flow is not too high, then control is fed back to block 302 and a new flow measurement is taken. If the measured flow is too high, the flow rate is reduced or choked in block 312 . The measured pressure is checked against the pressure guard band in block 314 if the measured pressure is within the guard band, a new flow measurement is taken by feeding back control to block 302 . If the measured pressure is outside the guard band, the pressure is reduced in block 316 . It will be understood that this flow chart is only representative of the possible implementations of the invention more fully described herein. Further, the desired flow may actually be represented as a range of acceptable flows.
Referring back to FIG. 3 , it will be appreciated that the temperature input can also come from the heating device 108 . For example, the heating device 108 may have a temperature output that couples to the third input 176 of the controller 146 . Under such an arrangement, the temperature sensor 144 in the flow monitor 118 is not required. It will be appreciated that numerous factors affect the decision to use a separate temperature sensor or whether the heating device 108 can generate sufficient temperature measurements including for example, the length of the first delivery line section 120 and the type of outputs available on the heating device 108 .
The optional temperature and pressure sensors 142 , 144 need not physically reside within the flow monitor 118 . Referring to FIG. 5 , the flow monitor 118 does not include a built in pressure sensor. Rather, a pressure sensor 178 is provided in line with the delivery line 116 . It is preferable to locate the pressure sensor 178 proximate to, and upstream from the flow monitor 118 , however, the pressure sensor 178 may also be positioned downstream of the flow monitor 118 . Further, the pressure sensor 178 may be positioned in any desired position along the delivery line 116 . It will be appreciated that a temperature sensor may also be positioned along the delivery line 116 (not shown) in a similar fashion as that described for the pressure sensor 178 .
Referring to FIG. 6 , a vapor delivery system according to another embodiment of the present invention is illustrated. As pointed out above, the flow monitor 118 controls the flow rate of the vapor 114 into the deposition chamber 124 through the second delivery line section 122 by choking the flow of vapor in the first delivery line section 120 to let the desired amount of flow through. However, as the vapor flow is choked off, pressure upstream of the flow monitor 118 increases. Whereas an embodiment of the present invention discussed above with reference to FIGS. 1–5 offsets the increased pressure during choked off periods by adjusting the temperature of the heating device 108 , the embodiment illustrated in FIG. 6 offsets the increased pressure by bleeding off excess vapor 114 .
The delivery line 116 further includes a third delivery line section 180 that couples to the first delivery line section 120 upstream of the flow monitor 118 . A valve 182 is positioned inline with the third delivery line section 180 , and a pump 184 is provided to draw vapor 114 in the direction of the third delivery line section 180 . The valve 182 can be any implemented with any number of valve arrangements, including a mass flow controller. For example, the valve 182 may comprise a pulsed gate flow or sonic nozzle mass flow controller 146 . Digital valves and pulsed gate flow devices are preferred over analog counterparts due to the fast response time and control typically afforded by such devices.
The controller 186 includes a first output 188 coupled to the valve 182 , and the logic in the controller 186 is configured to adjust the valve 182 to selectively bleed off vapor 114 in the first delivery line section 120 by siphoning excess vapor 114 through the third delivery line section 180 . That is, the measured vapor flow is compared to a predetermined vapor flow. If the measured vapor flow exceeds the desired vapor flow, any excess vapor is bled of by opening the valve 182 to draw a portion of the vapor 114 into the third delivery line section 180 and away from the flow monitor 118 . The controller 186 inputs and variations thereof are similar to those described more fully herein with reference to FIGS. 1–5 .
The heating device 108 is schematically illustrated as having a variable temperature control 110 because the temperature applied to the first surface 106 may require adjustment when switching from one solid precursor material 112 to the next. However, in this embodiment, it is not required that the heating device 108 be a fast response heater.
FIG. 7 illustrates the embodiment as illustrated in FIG. 6 with the addition of optional pressure regulation to assist in maintaining the solid precursor material 112 in the vapor phase. Similar to the pressure system discussed with reference to FIG. 3 , the inert gas 152 is provided by the gas source 154 and is fed into the vaporization chamber 102 through the gas line 156 . A flow regulator 158 is provided to control the amount of inert gas 152 that enters the vaporization chamber 102 . The controller 186 optionally comprises a second output 190 that couples to the flow regulator 158 to adjust the amount of inert gas 152 that is introduced during deposition processing. Further, depending upon the selection of solid precursor material 112 , an optional carrier gas 166 may be used to assist the vapor 114 in transmitting from the vaporization chamber 102 to the deposition chamber 124 . The carrier gas 166 is provided by a carrier gas source 167 , and is fed into the vaporization chamber 102 using a second gas line 168 , flow regulator 170 , and other components separate from the inert gas source 154 . FIG. 7 also illustrates the use first, second and third controller inputs 148 , 174 , and 176 from the flow sensor 136 , pressure sensor 142 , and temperature sensor 144 respectively. As previously described herein, the pressure and temperature sensors 142 , 144 are optional.
FIG. 8 illustrates another embodiment of the present invention. The vapor delivery system is similar to that described with reference to FIGS. 6–7 , and further includes a third output 192 that feeds back control from the controller 186 to the temperature control 110 of the heating device 108 . This structure allows a high degree of flexibility in the implementation of the controller 186 . For example, according to one embodiment of the present invention, the controller 186 is configured to adjust the temperature of the first surface 106 when coarse adjustments are required to the vapor flow. The controller 186 is configured to regulate the valve 182 when fine adjustments are required. It will be appreciated that depending upon such factors as the ability of the pump 184 to create a vacuum and the length of the third delivery line section 180 , the opening and closing the valve 182 can result in faster response times than regulating the heating device 108 .
According to another embodiment of the present invention, the controller 186 is arranged to regulate the valve 182 and adjust the temperature applied to the first surface 106 by adjusting the temperature control 110 generally at the same time. Alternatively, the controller 186 adjusts vapor flow by adjusting the third output 192 to change the temperature of the heating device 108 , and thus affecting vapor flow, and adjusting the first and second outputs 188 , 190 to adjust for measured pressure.
While illustrated having a pressure sensor 178 and a flow sensor 118 that includes a built in temperature sensor 144 , it will be appreciated that the inputs to the controller 186 can include any of the configurations discussed above with reference to FIGS. 1–7 .
Although the invention described above with reference to FIGS. 1–8 are illustrated with a single vaporization chamber 102 and a single solid precursor material 112 , it will be appreciated that any number of vaporization chambers 102 may feed into a single deposition chamber 124 using the techniques, methods, and system described herein.
Further, any number of additional features of conventional vapor delivery systems may be used with the present invention as is known in the art. For example, optional delivery line heaters may be used to maintain the solid precursor in the vapor phase. The use of delivery line heaters may be advantageous under conditions where excessive line length is required to deliver the solid precursor.
Having described the invention in detail and by reference to preferred 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.
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Systems and methods are provided for delivering solid precursors. In certain embodiments of the present application, a flow monitor is used to measure and regulate the flow of vaporized solid precursor material from a vaporization chamber to a deposition chamber. The flow monitor chokes the supply of vapor into the deposition chamber to regulate vapor flow. To avoid condensation of the solid precursor material in the delivery lines or flow monitor, a controller is placed in a feed back loop to monitor the flow rate and make adjustments to the amount of vapor available at the inlet of the flow monitor. Additional embodiments are disclosed and claimed.
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This is a division, of application Ser. No. 22,202 filed Mar. 19, 1979, now U.S. Pat. No. 4,334,577, which, in turn, is a continuation-in-part of application Ser. No. 804,594 filed June 8, 1977, now U.S. Pat. No. 4,157,984.
BACKGROUND OF THE INVENTION
It has heretofore been known that antioxidant properties are possessed by tempeh, a fermented soybean product obtained by fermenting soybeans with a fungus, either Rhizopus oligosporus or Rhizopus oryzae. Food products containing tempeh, such as fish or fatty meat food products exhibit improved stability, see U.S. Pat. No. 3,681,085 (1972). Further, it has heretofore been found that by extracting tempeh with a mixture of hexane and ethanol, a component of tempeh, namely oil of tempeh, can be recovered, see U.S. Pat. Nos. 3,762,933 (1973) and 3,855,256 (1974), which exhibits enhanced antioxidant properties relative to those of tempeh. It has also been previously known that the average serum cholesterol levels of persons living in Indonesia where tempeh is a food staple are reduced relative to those of persons living in Western countries.
SUMMARY OF THE INVENTION
The present invention involves the discovery that ergostadientriols which possess antioxidant properties are produced by the fungi Rhizopus oligosporus and Rhizopus oryzae and may be recovered therefrom. Alternatively, these ergostadientriols may be chemically synthesized. The ergostadientriols of this invention have the structure: ##STR1## wherein X may be hydrogen or a hydroxyl group provided that X twice be hydroxyl. This structure is intended to cover both α and β stereoisomers of the substituents at the 5 and 7 positions and accordingly for the purposes of this application no distinction shall be made between the α and β isomers.
These compounds possess antioxidant properties and may be utilized in the stabilization of a wide variety of food products including edible fats and oils. Furthermore, antioxidant compositions which include one or more ergostadientriol in accordance with the present invention and one or more isoflavone have been found to be especially effective in stabilizing various food products.
A particularly significant aspect of the present invention involves the discovery that pharmaceutical compositions which include one or more ergostadientriol having the structure set forth hereinabove and a pharmaceutically acceptable carrier are useful in reducing serum cholesterol levels.
One or more of the ergostadientriols of the present invention may be prepared by culturing the fungus R. oligosporus or the fungus R. oryzae and recovering the compound or compounds therefrom. The fungus typically produces a mixture of ergostadientriols in the presence of ultraviolet light. Specific sterols can then be separately recovered. If the fungus is cultured in the present of visible light, the formation of one of the sterols is favored, specifically, the ergostadientriol having the structure: ##STR2## Compound II can then be isolated and recovered from the fungus. Additionally, one or more of the ergostadientriols can be prepared by fermenting soybeans with R. oligosporus or R. oryzae, contacting the resulting fermented soybean product, i.e. tempeh, with methanol to separate from the fermented soybean product an extract containing one or more of the ergo-stadientriols and recovering the compound or compounds from the methanol extract. As is the case where the ergostadientriols are prepared by culturing of one of the fungi identified hereinabove, the presence of visible light during fermentation of the soybeans results in preferential formation of ergostadientriol II. Alternatively, the ergostadientriols may be prepared by chemical synthesis.
Finally, the present invention provides methods of preventing and/or treating diseases involving increased serum cholesterol levels which involve administering an effective amount of a pharmaceutical composition such as described herein to a patient or subject having an abnormally high serum cholesterol level.
Thus, it is a primary object of the present invention to provide pharmaceutical compositions which include one or more ergostadientriol and a pharmaceutically acceptable carrier.
It is another object to provide a novel compound useful in pharmaceutical and/or antioxidant compositions.
It is a related object to provide methods of preparing such compounds.
It is still another object to provide methods of preventing and/or treating diseases which are associated with increased serum cholesterol levels. Such therapeutic methods involve administration of an effective amount of a pharmaceutical composition which includes one or more of the ergostadientriols of the present invention.
It is a final object of this invention to provide antioxidant compositions which include one or more of the ergostadientriols in accordance with this invention.
How these and other objects of this invention are accomplished will become apparent upon reading the detailed description of the invention including the examples set forth, and the claims which follow. In at least one embodiment of the present invention at least one of the foregoing objects will be achieved.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with one embodiment of this invention, ergostadientriols having the structure: ##STR3## wherein X may be hydrogen or a hydroxyl group provided that X twice be hydroxyl have been prepared. These novel ergostadientriols possess antioxidative properties. They are "Emmerie Engel" positive at the same order of magnitude as Vitamin E, that is, they reduce Fe +++ to Fe ++ at room temperature, the latter forming a brilliant red complex in the presence of α, α-dipyridil. In combination with various isoflavones, these sterols provide antioxidant compositions with exceptional properties. The ergostadientriols I have been characterized by ultraviolet, infrared, and high resolution mass spectrometry as 3-hydroxy-ergosterols. The molecular formula of these compounds is C 28 H 46 O 3 , and their molecular weight 430. One such ergostadientriol has been identified as having the structure: ##STR4##
This ergostadientriol is a known compound, e.g., see Fieser and Fieser, Steroids, p. 98, (compound identified as Triol I(6)), Reinhold Publishing Corporation, New York (1959). However, its usefulness in reducing serum cholesterol levels has not previously been taught or suggested.
Another ergostadientriol has been identified as having the following structure: ##STR5##
This ergostadientriol is a novel compound.
As indicated hereinabove, in a preferred embodiment, the present invention provides pharmaceutical compositions which are useful in reducing serum cholesterol levels. Such pharmaceutical compositions comprise one or more compound having the structure: ##STR6## wherein X may be hydrogen or a hydroxyl group provided that X twice be hydroxyl, and a pharmaceutically acceptable carrier. Particularly preferred for use in such pharmaceutical compositions in ergostadientriol II which has the hydroxyl groups at the 5 and 8 positions. As used herein, pharmaceutically acceptable carrier includes without limitation all of the conventional carriers. Merely by way of illustration the following are set forth, namely, talc, starch, lactose, tragacanth, and magnesium sterate. Countless others are useful in the practices of the present invention and the choice of any specific carrier is one well within the skill of a person in the art.
Such pharmaceutical compositions may include one or more of the ergostadientriols of the present invention in amounts by weight ranging from about 0.001 to 10 percent, perferably, about 0.01 to 1.0 percent based upon the weight of said compositions. By administering such compositions to a patient or subject in an effective amount, such as an amount in the range 0.01-10 mg per kg of the patient's or subject's weight, serum cholesterol levels can be reduced. Accordingly, the present invention provides methods of preventing and/or treating diseases associated with increased serum cholesterol levels, such as atherosclerosis, which comprises administering to a subject or patient an effective amount of a pharmaceutical composition in accordance with the present invention.
In accordance with another embodiment of this invention, antioxidant compositions may be prepared which include one or more of the ergostadientriols I. As is disclosed more fully in co-pending, co-assigned application Ser. No. 804,594, filed June 8, 1977 referred to hereinabove and incorporated by reference into the present disclosure, compositions containing one or more ergostadientriol and one or more isoflavone provide exceptionally effective antioxidative properties. Specifically, antioxidant compositions which include an ergostadientriol having the structure: ##STR7## wherein X may be hydrogen or a hydroxyl group provided that X twice be hydroxyl, and one or more isoflavone having the structure: ##STR8## wherein the dashed lines may be carbon-carbon single bonds or carbon-carbon double bonds, and wherein X may be two hydrogen atoms or oxygen, and further wherein each of R, R' and R" may be a methyl group or hydrogen provide exceptional antioxidative properties as set forth in the examples hereinbelow.
Such antioxidant compositions can be included in food products to produce stabilized food compositions. Accordingly, food products such as fish, fatty meat or derivatives thereof, may be stabilized by the addition thereto of an antioxidant composition which includes one or more of the ergostadientriols described hereinabove in an amount from about 0.001 to 10 percent by weight. Additionally, stabilized edible oil and/or fat compositions may be prepared by including in edible oils or fats an antioxidant composition which includes one or more of the ergostadientriols of the present invention. Effective amounts of such antioxidant compositions in terms of improving the stability of oils or fats, such as for example, lard, corn oil, olive oil, soybean oil or palm oil, and the like are amounts in the range 0.01 to 1.0 percent by weight, more or less.
The ergostadientriols I may be produced by fermentation of soybeans with a fungus, either R. oligosporus or R. oryzae. The ergostadientriols may also be produced by and recovered from either of these fungi directly after growth on a suitable culture medium. Suitable fungi for producing the ergostadientriols are Rhizopus oligosporus ATCC No. 22959 and Rhizopus oryzae ATCC No. 9363. If the fermentation of soybeans with fungus, or the culturing of fungus directly is carried out in the presence of ultraviolet light, a mixture of ergostadientriols, each of which falls within the scope of structure I is produced including compounds II and III. However, it has been found that if the fermentation or culturing is carried out in the presence of visible light, there is a preferential formation of ergostadientriol II which has the hydroxyl groups at the 5 and 8 positions as shown hereinabove. The ergostadientriol or ergostadientriols so prepared may be recovered in the following manner. Dry, e.g., lyophilized, tempeh powder or cultured fungus is contacted with a 60-70% aqueous methanol solution for an extended period of time, for example, overnight, at a temperature of about 4° C. thereby producing an extract of methanol-soluble components including one or more of the ergostadientriols I. The methanol extract solution, after removal of insoluble material, is evaporated to dryness, preferably in vacuo, at an elevated temperature, for example, about 40°-60° C. A solid residue is produced, most of which is redissolved upon contact with dry methanol. That portion of the residue which is methanol insoluble is separated from the soluble components by centrifugation and discarded. After centrifugation the methanol supernatant is extracted with hexane several times, for example, two to three times, in order to remove any traces of hexane-soluble impurities, such as lipids. After discarding the resulting hexane extract, the remaining methanol supernatant is evaporated to reduce its volume to a minimal fraction, for example, about 20 ml, and kept at a temperature of about -20° C. for about 15-20 minutes. This results in formation of additional precipitate which is removed and discarded.
The ergostadientriols may then be recovered from the methanol supernatant or extract as follows. The supernatant is subjected to molecular sieve chromatography, for example, chromatography on Sephadex LH20 using a suitable size column, for example, 2×40 cm, and a suitable mobile phase, for example, n-propanol:ethylacetate:water in a ratio 5:5:1. One of the fractions resulting from this chromatographic separation is fluorescent with emission in the blue range of the visible spectrum. This blue fluorescent fraction is separated and subjected to adsorption chromatography on a suitable matrix, for example, silica gel, using an appropriate mobile phase, for example, ethylacetate:propanol:water=95:2:3. The resulting blue flurorescent fraction is then re-chromatographed on an adsorptive matrix, for example, silica gel again, employing a different mobile phase, for example, cyclohexane:dichloromethane:ethyl formate:formic acid=35:30:30:5. Each of the ergostadientriols present can then be recovered in essentially pure form using its differential mobility on the silica gel plate.
Additionally, the ergostadientriols may also be obtained in pure form from the methanol supernatant or extract by preparative high pressure liquid gas chromatography.
Alternatively, the ergostadientriols may be chemically synthesized. For example, ergostadientriol II may be prepared from ergosterol by the method outlined in Fieser and Fieser, Steroids, p. 98 and referred to hereinabove.
In addition to the ergostadientriols discussed hereinabove it would appear that compounds having the structure ##STR9## wherein R 1 may be --OH, ═O, --H, --O--Alkyl, --O--Acyl, --COOH, --COOAlkyl or C.tbd.N and wherein R 2 may be ##STR10## including without limitation the various sterochemically possible connections of Rings A,B,C and D, the reduction and addition reaction products which may be obtained by reactions involving the double bond on C 6 , particularly the epoxidation and hydroxylation products, and compounds having an additional double bond between C 9 and C 11 may be useful in lowering serum cholesterol levels.
EXAMPLE I
Ergostadientriol II was compared with β-sitosterol, a commercially available hypocholesterolemic agent to determine its effect upon serum cholesterol levels in chicks feed a high cholesterol diet.
In the bioassey there were four groups of three pens per group and five chicks per pen. Each group was fed a high cholesterol diet for seven days prior to blood sampling. One group served as control. Two groups were fed β-sitosterol at the level of 1.0% and 0.1% of the feed and one group was fed ergostadientriol II at a level of 0.1% of the feed. The results were as follows:
______________________________________ Serum Cholesterol (mg %)______________________________________Control 330.7 ± 15.80.1% β-sitosterol 333.3 ± 7.91.0% β-sitosterol 286.9 ± 14.90.1% ergostadientriol II 283.8 ± 23.4______________________________________
Statistical analysis of the data shows that the addition of 0.1% ergostadientriol II to the feed decreased serum cholesterol by 14.2% compared to the controls. 1.0% β-sitosterol was required to reduce cholesterol by 13.2% compared to the controls. Thus, ergostadientriol II was more than 10 times as active as β-sitosterol in reducing serum cholesterol.
The results of this test would indicate to one skilled in the art that the ergostadientriol would be effective in reducing serum cholesterol levels in human patients. Furthermore, these results would strongly suggest to one skilled in the art that the ergostadientriol would be useful in treating and/or preventing diseases associated with increased serum cholesterol levels such as athersclerosis.
EXAMPLE II
In a standard test assay involving oxidation of lard by exposure to air at 60° C. for 72 hours, ergostadientriol III may be added at a concentration of 0.1 percent by weight. This addition of the ergostadientriol should result in about 50% protection against oxidation.
EXAMPLE III
The same test as in Example II may be carried out except that the concentration of ergostadientriol III is 0.01 percent by weight. This reduced concentration should still provide about 25% protection against oxidation.
EXAMPLE IV
An antioxidant composition may be prepared by mixing ergostadientriol III and an isoflavone having the structure: ##STR11## When added to lard at concentrations of each component of 0.01%, this composition should provide essentially 100% protection against oxidation in the standard assay.
EXAMPLE V
An antioxidant composition may be prepared by mixing ergostadientriol II and an isoflavone having the structure ##STR12## At a concentration of 0.01-0.1% by weight of each compound this antioxidant composition would provide substantial protection against oxidation.
As will be obvious to one skilled in the art, many modifications, variations, alterations and the like may be made in the practices of this invention without departing from the spirit and scope thereof as set forth in the claims which follow.
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The present invention concerns ergostadientriols which may be recovered from either the fungus R. oligosporus or the fungus R. oryzae as well as from soybeans which have been fermented with either of these fungi. Alternatively, the sterols may be chemically synthesized. The sterols of this invention are antioxidants which may be used in anti-oxidant compositions alone or preferably with one or more isoflavone. Of particular significance is the discovery that the ergostadientriols of this invention are useful in lowering serum cholesterol levels. Accordingly, this invention in a particularly preferred embodiment discloses pharmaceutical compositions containing one or more ergostadientriol. Finally, therapeutic methods which utilize pharmaceutical compositions in accordance with this invention are disclosed.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of U.S. patent application Ser. No. 09/975,471, filed Oct. 11, 2001, now allowed, which is a continuation-in-part of U.S. patent application Ser. No. 09/789,936, filed Feb. 15, 2001, now abandoned, the disclosures of which are hereby incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates generally to a spinal implant assembly for implantation into the intervertebral space between adjacent vertebral bones to simultaneously provide stabilization and continued flexibility and proper anatomical motion, and more specifically to such a device which utilizes a spirally slotted belleville washer, having radially spaced concentric grooves, as a restoring force generating element.
BACKGROUND OF THE INVENTION
[0003] The bones and connective tissue of an adult human spinal column consists of more than 20 discrete bones coupled sequentially to one another by a tri-joint complex which consists of an anterior disc and the two posterior facet joints, the anterior discs of adjacent bones being cushioned by cartilage spacers referred to as intervertebral discs. These more than 20 bones are anatomically categorized as being members of one of four classifications: cervical, thoracic, lumbar, or sacral. The cervical portion of the spine, which comprises the top of the spine, up to the base of the skull, includes the first 7 vertebrae. The intermediate 12 bones are the thoracic vertebrae, and connect to the lower spine comprising the 5 lumbar vertebrae. The base of the spine is the sacral bones (including the coccyx). The component bones of the cervical spine are generally smaller than those of the thoracic spine, which are in turn smaller than those of the lumbar region. The sacral region connects laterally to the pelvis. While the sacral region is an integral part of the spine, for the purposes of fusion surgeries and for this disclosure, the word spine shall refer only to the cervical, thoracic, and lumbar regions.
[0004] The spinal column of bones is highly complex in that it includes over twenty bones coupled to one another, housing and protecting critical elements of the nervous system having innumerable peripheral nerves and circulatory bodies in close proximity. In spite of these complications, the spine is a highly flexible structure, capable of a high degree of curvature and twist in nearly every direction.
[0005] Genetic or developmental irregularities, trauma, chronic stress, tumors, and degenerative wear are a few of the causes that can result in spinal pathologies for which surgical intervention may be necessary. A variety of systems have been disclosed in the art which achieve immobilization and/or fusion of adjacent bones by implanting artificial assemblies in or on the spinal column. The region of the back which needs to be immobilized, as well as the individual variations in anatomy, determine the appropriate surgical protocol and implantation assembly. With respect to the failure of the intervertebral disc, the interbody fusion cage has generated substantial interest because it can be implanted laparoscopically into the anterior of the spine, thus reducing operating room time, patient recovery time, and scarification.
[0006] Referring now to FIGS. 1 and 2 , in which a side perspective view of an intervertebral body cage and an anterior perspective view of a post implantation spinal column are shown, respectively, a more complete description of these devices of the prior art is herein provided. These cages 10 generally comprise tubular metal body 12 having an external surface threading 14 . They are inserted transverse to the axis of the spine 16 , into preformed cylindrical holes at the junction of adjacent vertebral bodies (in FIG. 2 the pair of cages 10 are inserted between the fifth lumbar vertebra (L 5 ) and the top of the sacrum (S 1 ). Two cages 10 are generally inserted side by side with the external threading 14 tapping into the lower surface of the vertebral bone above (L 5 ), and the upper surface of the vertebral bone (S 1 ) below. The cages 10 include holes 18 through which the adjacent bones are to grow. Additional material, for example autogenous bone graft materials, may be inserted into the hollow interior 20 of the cage 10 to incite or accelerate the growth of the bone into the cage. End caps (not shown) are often utilized to hold the bone graft material within the cage 10 .
[0007] These cages of the prior art have enjoyed medical success in promoting fusion and grossly approximating proper disc height. It is, however, important to note that the fusion of the adjacent bones is an incomplete solution to the underlying pathology as it does not cure the ailment, but rather simply masks the pathology under a stabilizing bridge of bone. This bone fusion limits the overall flexibility of the spinal column and artificially constrains the normal motion of the patient. This constraint can cause collateral injury to the patient's spine as additional stresses of motion, normally borne by the now-fused joint, are transferred onto the nearby facet joints and intervertebral discs. It would therefore, be a considerable advance in the art to provide an implant assembly which does not promote fusion, but, rather, which nearly completely mimics the biomechanical action of the natural disc cartilage, thereby permitting continued normal motion and stress distribution.
[0008] It is, therefore, an object of the present invention to provide a new and novel intervertebral spacer which stabilizes the spine without promoting a bone fusion across the intervertebral space.
[0009] It is further an object of the present invention to provide an implant device which stabilizes the spine while still permitting normal motion.
[0010] It is further an object of the present invention to provide a device for implantation into the intervertebral space which does not promote the abnormal distribution of biomechanical stresses on the patient's spine.
[0011] Other objects of the present invention not explicitly stated will be set forth and will be more clearly understood in conjunction with the descriptions of the preferred embodiments disclosed hereafter.
SUMMARY OF THE INVENTION
[0012] The preceding objects of the invention are achieved by the present invention which is a flexible intervertebral spacer device comprising a pair of spaced apart base plates, arranged in a substantially parallel planar alignment (or slightly offset relative to one another in accordance with proper lordotic angulation) and coupled to one another by means of a spring mechanism. In particular, this spring mechanism provides a strong restoring force when a compressive load is applied to the plates, and may also permit rotation of the two plates relative to one another. While there are a wide variety of embodiments contemplated, a preferred embodiment includes a belleville washer utilized as the restoring force providing element, the belleville washer being spirally slotted and having radially spaced concentric grooves.
[0013] More particularly, as the assembly is to be positioned between the facing surfaces of adjacent vertebral bodies, the base plates should have substantially flat external surfaces which seat against the opposing bone surfaces. Inasmuch as these bone surfaces are often concave, it is anticipated that the opposing plates may be convex in accordance with the average topology of the spinal anatomy. In addition, the plates are to mate with the bone surfaces in such a way as to not rotate relative thereto. (The plates rotate relative to one another, but not with respect to the bone surfaces to which they are each in contact with.) In order to prevent rotation of a plate relative to the bone, the upper and lower plates can include a porous coating into which the bone of the vertebral body can grow. (Note that this limited fusion of the bone to the base plate does not extend across the intervertebral space.)
[0014] In some embodiments (not in the preferred embodiment), between the base plates, on the exterior of the device, there is included a circumferential wall which is resilient and which simply prevents vessels and tissues from entering within the interior of the device. This resilient wall may comprise a porous fabric or a semi-impermeable elastomeric material. Suitable tissue compatible materials meeting the simple mechanical requirements of flexibility and durability are prevalent in a number of medical fields including cardiovascular medicine, wherein such materials are utilized for venous and arterial wall repair, or for use with artificial valve replacements. Alternatively, suitable plastic materials are utilized in the surgical repair of gross damage to muscles and organs. Still further materials that could be utilized herein may be found in the field of orthopedic in conjunction with ligament and tendon repair. It is anticipated that future developments in this area will produce materials that are compatible for use with this invention, the breadth of which shall not be limited by the choice of such a material.
[0015] As introduced above, the internal structure of the present invention comprises a spring member, which provides a restoring force when compressed. More particularly, it is desirable that the restoring forces be directed outward against the opposing plates, when a compressive load is applied to the plates. In addition, in certain embodiments, it is necessary that the restoring force providing subassembly not substantially interfere with the rotation of the opposing plates relative to one another. In the preferred embodiment, the spring subassembly is configured to allow rotation of the plates relative to one another. In other embodiments, the spring subassembly can be configured to either allow rotation of the plates, or prevent rotation of the plates (through the tightening of a set screw as discussed below). As further mentioned above, the force restoring member comprises at least one belleville washer.
[0016] Belleville washers are washers which are generally bowed in the radial direction. Specifically, they have a radial convexity (i.e., the height of the washer is not linearly related to the radial distance, but may, for example, be parabolic in shape). The restoring force of a belleville washer is proportional to the elastic properties of the material. In addition, the magnitude of the compressive load support and the restoring force provided by the belleville washer may be modified by providing slots and/or grooves in the washer. In the preferred embodiment of the present invention, the belleville washer utilized as the force restoring member is spirally slotted, with the slots initiating on the periphery of the washer and extending along arcs which are generally radially inwardly directed a distance toward the center of the bowed disc, and has radially uniformly spaced concentric grooves of uniform width and depth.
[0017] As a compressive load is applied to a belleville washer, the forces are directed into a hoop stress which tends to radially expand the washer. This hoop stress is counterbalanced by the material strength of the washer, and the strain of the material causes a deflection in the height of the washer. Stated equivalently, a belleville washer responds to a compressive load by deflecting compressively, but provides a restoring force which is proportional to the elastic modulus of the material in a hoop stressed condition. With slots and/or radially spaced concentric grooves formed in the washer, it expands and restores itself far more elastically than a solid washer.
[0018] In general, the belleville washer is one of the strongest configurations for a spring, and is highly suitable for use as a restoring force providing subassembly for use in an intervertebral spacer element which must endure considerable cyclical loading in an active human adult.
[0019] In the preferred embodiment of the present invention, a single modified belleville washer, which is of the slotted variety and has radially spaced concentric grooves as described above, is utilized in conjunction with a ball-shaped post on which it is free to rotate through a range of angles (thus permitting the plates to rotate relative to one another through a corresponding range of angles). More particularly, this embodiment comprises a pair of spaced apart base plates, one of which is simply a disc shaped member (preferably shaped to match the end of an intervertebral disc) having an external face (having the porous coating discussed above) and an internal face having an annular retaining wall (the purpose of which will be discussed below). The other of the plates is similarly shaped, having an exterior face with a porous coating, but further includes on its internal face a central post portion which rises out of the internal face at a nearly perpendicular angle. The top of this post portion includes a ball-shaped knob. The knob includes a central threaded axial bore which receives a small set screw. Prior to the insertion of the set screw, the ball-shaped head of the post can deflect radially inward (so that the ball-shaped knob contracts). The insertion of the set screw eliminates the capacity for this deflection.
[0020] As introduced above, a modified and spirally slotted belleville washer having radially spaced concentric grooves is mounted to this ball-shaped knob in such a way that it may rotate freely through a range of angles equivalent to the fraction of normal human spine rotation (to mimic normal disc rotation). The belleville washer of this design is modified by including an enlarged inner circumferential portion (at the center of the washer) which accommodates the ball-shaped portion of the post. More particularly, the enlarged portion of the modified belleville washer includes a curvate volume having a substantially constant radius of curvature which is also substantially equivalent to the radius of the ball-shaped head of the post. The deflectability of the ball-shaped head of the post, prior to the insertion of the set screw, permits the head to be inserted into the interior volume at the center of the belleville washer. Subsequent introduction of the set screw into the axial bore of the post prevents the ball-shaped head from deflecting. Thereby, the washer can be secured to the ball-shaped head so that it can rotate thereon through a range of proper lordotic angles (in some embodiments, a tightening of the set screw locks the washer on the ball-shaped head at one of the lordotic angles).
[0021] This assembly provides ample spring-like performance with respect to axial compressive loads, as well as long cycle life to mimic the axial biomechanical performance of the normal human intervertebral disc. The spiral slots and radially spaced concentric grooves of the belleville washer allow the washer to expand radially as the slots and grooves widen under the load, only to spring back into its undeflected shape upon the unloading of the spring. As the washer compresses and decompresses, the annual retaining wall maintains the wide end of the washer within a prescribed boundary on the internal face of the base plate which it contacts, and an annular retaining ring maintains the wide end of the washer against the internal face.
[0022] Finally, inasmuch as the human body has a tendency to produce fibrous tissues in perceived voids, such as may be found within the interior of the present invention, and such fibrous tissues may interfere with the stable and/or predicted functioning of the device, some embodiments of the present invention (although not the preferred embodiment) will be filled with a highly resilient elastomeric material. The material itself should be highly biologically inert, and should not substantially interfere with the restoring forces provided by the spring-like mechanisms therein. Suitable materials may include hydrophilic monomers such as are used in contact lenses. Alternative materials include silicone jellies and collagens such as have been used in cosmetic applications. As with the exterior circumferential wall, which was described above as having a variety of suitable alternative materials, it is anticipated that future research will produce alternatives to the materials described herein, and that the future existence of such materials which may be used in conjunction with the present invention shall not limit the breadth thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a side perspective view of an interbody fusion device of the prior art.
[0024] BRIEF FIG. 2 is a front view of the anterior portion of the lumbo-sacral region of a human spine, into which a pair of interbody fusion devices of the type shown in FIG. 1 have been implanted.
[0025] FIGS. 3 a and 3 b are side cross-section views of the upper and lower opposing plates of the preferred embodiment of the present invention.
[0026] FIGS. 4 a and 4 b are top and side cross-section view of a belleville washer having radially uniformly spaced concentric grooves of uniform width and depth and spiral slots, for use in a preferred embodiment of the present invention.
[0027] FIGS. 5 a - 5 c are top and side cross-section views of a belleville washer having radially non-uniformly spaced concentric grooves of varying width and depth and spiral slots, for use in an alternate embodiment of the present invention.
[0028] FIG. 6 a is a top view of the upper plate of FIG. 3 a , with the belleville washer of FIGS. 4 a and 4 b fitted within a retaining wall and a retaining ring of the upper plate.
[0029] FIG. 6 b is a top view of the lower plate of FIG. 3 b.
[0030] FIG. 7 is a side cross-section view of the preferred embodiment of the present invention, which utilizes a belleville washer of the type shown in FIGS. 4 a and 4 b , showing the plates of FIGS. 6 a and 6 b assembled together.
[0031] FIG. 8 a is a top view of the upper plate of FIG. 3 a , with the belleville washer of FIGS. 5 a - 5 c fitted within a retaining wall and a retaining ring of the upper plate.
[0032] FIG. 8 b is a top view of the lower plate of FIG. 3 b.
[0033] FIG. 9 is a cross-section view of an alternate embodiment of the present invention, which utilizes a belleville washer of the type shown in FIGS. 5 a - 5 c , showing the plates of FIGS. 8 a and 8 b assembled together.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which particular embodiments and methods of implantation are shown, it is to be understood at the outset that persons skilled in the art may modify the invention herein described while achieving the functions and results of this invention. Accordingly, the descriptions which follow are to be understood as illustrative and exemplary of specific structures, aspects and features within the broad scope of the present invention and not as limiting of such broad scope. Like numbers refer to similar features of like elements throughout.
[0035] Referring now to FIGS. 3 a and 3 b , side cross-section views of upper and lower plate members 100 , 200 of the preferred embodiment of the present invention are shown. As the device is designed to be positioned between the facing surfaces of adjacent vertebral bodies, the plates include substantially flat external face portions 102 , 202 which seat against the opposing bone surfaces. In addition, the plates are to mate with the bone surfaces in such a way as to not rotate relative thereto. It is, therefore, preferred that the external faces of the plates include a porous coating 104 , 204 into which the bone of the vertebral body can grow. (Note that this limited fusion of the bone to the base plate does not extend across the intervertebral space.) A hole (not shown) can be provided in the upper plate such that the interior of the device may be readily accessed if a need should arise.
[0036] The upper plate 100 includes an internal face 103 that includes an annular retaining wall 108 and an annular retaining ring 109 . The lower plate 200 includes an internal face 203 that includes a central post member 201 which rises out of the internal face 203 at a nearly perpendicular angle. The top of this post member 201 includes a ball-shaped head 207 . The head 207 includes a series of slots which render it compressible and expandable in correspondence with a radial pressure (or a radial component of a pressure applied thereto). The head 207 includes a central threaded axial bore 209 which extends down the post 201 . This threaded bore 209 is designed to receive a set screw 205 . Prior to the insertion of the set screw 205 , the ball-shaped head 207 of the post 201 can deflect radially inward because of the slots (so that the ball-shaped head contracts). The insertion of the set screw 205 eliminates the capacity for this deflection.
[0037] Referring now to FIGS. 4 a and 4 b , a spirally slotted belleville washer 130 having radially spaced concentric grooves is provided in top and side cross-section views. The belleville washer 130 is a restoring force providing device which comprises a circular shape, having a central opening 132 , and which is radially arched in shape. The belleville washer 130 has a radial convexity 134 (i.e., the height of the washer 130 is not linearly related to the radial distance, but may, for example, be parabolic in shape). The restoring force of the belleville washer 130 is proportional to the elastic properties of the material.
[0038] The belleville washer 130 comprises a series of spiral slots 131 formed therein. The slots 131 extend from the outer edge of the belleville washer, inward along arcs generally directed toward the center of the element. The slots 131 do not extend fully to the center of the element. In preferred embodiments, the slots may extend anywhere from a quarter to three quarters of the overall radius of the washer, depending upon the requirements of the patient, and the anatomical requirements of the device.
[0039] The belleville washer 130 further comprises a series of grooves 133 formed therein. The grooves 133 are concentric and radially spaced from the outer edge of the belleville washer toward the center of the element. In the preferred embodiment shown in FIGS. 4 a and 4 b , the width 135 of each groove 133 is uniform along the length of the groove 133 . Further in the preferred embodiment, the depth 137 of each groove 133 is uniform along the length of the groove 133 . Further in the preferred embodiment, each groove 133 has a different width configuration and a different depth configuration than each other groove 133 . More specifically, in the preferred embodiment, the width dimension and the depth dimension both vary from groove to groove, each increasing incrementally from groove to adjacent groove with increasing distance from the center of the washer 130 . Stated alternatively, grooves that are relatively more narrow and more shallow than the other grooves are closer to the center of the washer, whereas grooves that are relatively wider and deeper than the other grooves are closer to the outer edge of the washer. This is illustrated by example in FIGS. 4 a and 4 b , which show three concentric grooves 133 a - c , with the outermost groove 133 c being deeper and wider than groove 133 b , which is in turn deeper and wider than groove 133 a . Further in the preferred embodiment, the radial spacing of the grooves is uniform.
[0040] It should be understood that in other embodiments, one or both of the depth and the width of each groove can be (1) increasing along the length of the groove, (2) decreasing along the length of the groove, or (3) varied along the length of each groove, either randomly or according to a pattern. Moreover, in other embodiments, it can be the case that each groove is not formed similarly to one or more other grooves, with or without respect to width and depth dimensions, but rather one or more grooves are formed in any of the above-mentioned fashions, while one or more other grooves are formed in another of the above-mentioned fashions or other fashions. Also, in other embodiments, it can be the case that the radial distance between the grooves is not the same, but rather the spacing increases the closer the space is to the outer edge of the washer, decreases the closer the space is to the outer edge of the washer, or varies either randomly or according to a pattern. Also, while the grooves of the preferred embodiment and the illustrated alternate embodiment have lengths that form closed loops, it should be noted that in other embodiments, the concentric grooves can have lengths that form open loops or arcs; for example, a two concentric grooves forming open loops or arcs can be used in place of a single concentric groove forming a closed loop. It should be clear that any concentric groove pattern can be implemented without departing from the scope of the present invention. To illustrate an alternate embodiment showing an alternate radially spaced concentric groove pattern, FIGS. 5 a - 5 c show a belleville washer 130 having radially spaced concentric grooves 133 in top and side cross-section views, with each groove 133 having a width and a depth each varying along the length of the groove 133 , with each groove 133 being formed differently than at least one other groove 133 , with the radial spacing of the grooves 133 being varied, and with both closed loops and open loops or arcs being used. In this alternate embodiment, the difference between the grooves 133 is characterized in that the wider and deeper portion of any particular groove 133 is on a different side of the washer 130 than the wider and deeper portion of at least one other groove 133 .
[0041] As a compressive load is applied to the belleville washer 130 of the present invention, the forces are directed into a hoop stress which tends to radially expand the washer. This hoop stress is counterbalanced by the material strength of the washer, and the force necessary to widen the spiral slots 131 and the radially spaced concentric grooves 133 along with the strain of the material causes a deflection in the height of the washer. Stated equivalently, the belleville washer 130 responds to a compressive load by deflecting compressively; the spiral slots and/or radially spaced concentric grooves cause the washer to further respond to the load by spreading as the slots and/or the grooves in the washer expand under the load. The spring, therefore, provides a restoring force which is proportional to the elastic modulus of the material in a hoop stressed condition.
[0042] More particularly, the central opening 132 of the belleville washer is enlarged. This central opening 132 includes a curvate volume 233 for receiving therein the ball-shaped head 207 of the post 201 of the lower plate 200 described above. More particularly, the curvate volume 233 has a substantially constant radius of curvature which is also substantially equivalent to the radius of the ball-shaped head 207 of the post 201 . In this embodiment, the spiral slots 131 do not extend all the way to the central opening 132 , and approach the opening only as far as the material strength of the washer can handle without plastically deforming under the expected anatomical loading. Preferably, the center of the washer is flat; therefore, the central opening 132 can be formed from flat edges. It should be understood that this is not required, but rather is preferred.
[0043] Referring now to FIG. 6 a , a top view of the upper plate 100 of FIG. 3 a , with the spirally slotted and concentrically grooved belleville washer 130 of FIGS. 4 a and 4 b fitted within a retaining wall 108 and a retaining ring 109 of the upper plate 100 , is shown. The diameter of the retaining wall 108 is preferably slightly wider than the diameter of the undeflected belleville washer 130 such that the loading thereof can result in an unrestrained radial deflection of the washer 130 . FIG. 6 b shows a top view of the lower plate 200 of FIG. 3 b.
[0044] FIG. 7 shows the fully assembled preferred embodiment of the present invention. The spirally slotted and radially grooved belleville washer 130 of FIGS. 4 a and 4 b is placed with its wide end against the top plate 100 within the annular retaining wall 108 as shown in FIG. 6 b . The annular retaining ring 109 is provided to hold the belleville washer 130 against the internal face 103 of the upper plate 100 within the retaining wall 108 . The post 201 of the lower plate 200 is fitted into the central opening 132 of the belleville washer 130 (the deflectability of the ball-shaped head 207 of the post 201 , prior to the insertion of the set screw 205 , permits the head 207 to be inserted into the interior volume 233 at the center of the belleville washer 130 . Subsequent introduction of the set screw 205 into the axial bore 209 of the post 201 eliminates the deflectability of the head 207 so that the washer 130 cannot be readily removed therefrom, but can still rotate thereon. In some embodiments (not in this preferred embodiment), the post head 207 can be locked tightly within the central volume 233 of the belleville washer 130 by the tightening of the set screw 205 , to prevent any rotation of the plates 100 , 200 . Compressive loading of the assembly causes the washer 130 to deflect (with the spiral slots and the radially spaced concentric grooves enhancing the deflection) so that the wide end radially expands while being maintained centrally against the upper plate 100 by the retaining wall 108 and the retaining ring 109 . When the load is removed, the washer 130 springs back to its original shape.
[0045] Referring now to FIG. 8 a , a top view of the upper plate 100 of FIG. 3 a , with the spirally slotted and concentrically grooved belleville washer 130 of FIGS. 5 a - 5 c fitted within a retaining wall 108 and a retaining ring 109 of the upper plate 100 , is shown. The diameter of the retaining wall 108 is preferably slightly wider than the diameter of the undeflected belleville washer 130 such that the loading thereof can result in an unrestrained radial deflection of the washer 130 . FIG. 8 b shows a top view of the lower plate 200 of FIG. 3 b.
[0046] FIG. 9 shows a fully assembled alternate embodiment of the present invention. The spirally slotted and concentrically grooved belleville washer 130 of FIGS. 5 a - 5 c is placed with its wide end against the top plate 100 within the annular retaining wall 108 as shown in FIG. 6 b . The annular retaining ring 109 is provided to hold the belleville washer 130 against the internal face 103 of the upper plate 100 within the retaining wall 108 . The post 201 of the lower plate 200 is fitted into the central opening 132 of the belleville washer 130 (the deflectability of the ball-shaped head 207 of the post 201 , prior to the insertion of the set screw 205 , permits the head 207 to be inserted into the interior volume 233 at the center of the belleville washer 130 , and the washer 130 to be rotated into the desired angulation; subsequent introduction of the set screw 205 into the axial bore 209 of the post 201 eliminates the deflectability of the head 207 so that the washer 130 cannot be readily removed therefrom, but can still rotate thereon.). The post head 207 can be locked tightly within the central volume 233 of the belleville washer 130 by the tightening of the set screw 205 , to prevent any rotation of the plates 100 , 200 . Compressive loading of the assembly causes the washer 130 to deflect (with the spiral slots and radially spaced concentric grooves enhancing the deflection) so that the wide end radially expands while being maintained centrally against the upper plate 100 by the retaining wall 108 and the retaining ring 109 . When the load is removed, the washer 130 springs back to its original shape.
[0047] Inasmuch as the human body has a tendency to produce fibrous tissues in perceived voids, such as may be found within the interior of the present invention, and such fibrous tissues may interfere with the stable and/or predicted functioning of the device, some embodiments of the present invention (although not the preferred embodiment) will be filled with a highly resilient and biologically inert elastomeric material. Suitable materials may include hydrophilic monomers such as are used in contact lenses. Alternative materials include silicone jellies and collagens such as have been used in cosmetic applications.
[0048] While there has been described and illustrated specific embodiments of an intervertebral spacer device, it will be apparent to those skilled in the art that variations and modifications are possible without deviating from the broad spirit and principle of the present invention. The invention, therefore, shall not be limited to the specific embodiments discussed herein.
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An intervertebral spacer device includes a first plate having a bone engaging face and an inner face, and a second plate having a second bone engaging face and a second inner face, the first and second plates being juxtaposed with one another so that the first inner face of the first plate opposes the second inner face of the second plate. The spacer device also includes a belleville washer disposed between the first inner face of the first plate and the second inner face of the second plate for counteracting compressive loads applied to the first and second plates. The belleville washer has at least one concentric groove and at least one spiral slot, whereby the at least one concentric groove has a depth and a width, with at least one of the widths and the depths varying along the length of the at least one concentric groove.
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FIELD OF THE INVENTION
This invention pertains generally to induction heating and cooking apparatus, and in particular to a new and improved cooking assembly of the ceramic cooking support plate, the inductive heating coil and the associated trim, which improves cooking performance and reduces magnetic flux leakage.
BACKGROUND OF THE INVENTION
Apparatus for magnetically coupling an induction heating coil with a ferrous cooking utensil to thereby electromagnetically heat the contents of the utensil have been widely known and used for many years. In such apparatus, the induction coil is usually located below a nonmagnetic cooking surface and an alternating current through the coil causes a continuously changing magnetic field to be generated. The magnetic field extends through the cooking surface to link with the cooking utensil to cause eddy currents in the utensil and allow it to heat up.
Commercial versions of induction cooking apparatus provide for a plurality of cooking areas on a smooth-top cooking surface made from a single continuous rectangular piece of ceramic material. Each designated cooking area on the cooking surface has an induction cooking coil located thereunder so that cooking utensils placed on the designated cooking areas will be linked by the magnetic field generated by the cooking coil.
One problem associated with this construction is cost; the ceramic cooktop is more expensive than a comparably sized sheet steel cooktop typically used in conventional electric or gas ranges.
Another problem is electromagnetic leakage. The electromagnetic leakage problem is aggravated by a variety of factors. One factor is the misalignment of a cooking utensil with the magnetic field generated by the cooking coil. This problem is addressed in the context of a conventional induction cooking construction by providing utensil presence and position detection apparatus which insure that the induction coil is not energized unless the cooking utensil is both present on the cooktop and centered over the induction heating coil.
These sensing arrangements are designed to insure that the high intensity electromagnetic fields which emanate from the induction heating coil are generated only when a utensil is in position and centered over the induction heating coil, thereby limiting the undesirable transmission or leakage of electromagnetic flux into the free space surrounding the cooking appliance. Neither of these approaches, however, addresses the problem of electromagnetic leakage resulting from the high reluctance gap present in the flux path between the edges of the cooking utensil and the flux-shaping coil support structure. This latter situation creates an undesirable condition which results in the leakage of excessive magnetic flux into the space surrounding the cooking surface, which leakage may cause interference with television and radio signals and other communication systems. For this reason, among others, governmental regulating agencies have set limits on the magnetic field leakage of this type attendant to the use of induction heating appliances. Since the intensity of flux leaking into surrounding space increases as a result of operation of an induction heating unit with such high reluctance gaps, it is desirable to provide an arrangement for operation of the unit without such gaps or with a reduced number of them.
OBJECTS AND SUMMARY OF THE INVENTION
A primary object of the invention, therefore, is the provision of an induction cooking arrangement which is simple in design, and inexpensive in implementation.
A further object of the invention is the provision of an induction cooking apparatus which employs small individual ceramic plates as cooking surfaces for each cooking area, each plate being supported in a main horizontal sheet metal cooktop surface.
A further object is the provision of an induction cooking apparatus having a plurality of cooking units, each unit including a ceramic plate supported in an opening in an otherwise continuous sheet metal support surface.
A still further object of the invention is to provide an improved arrangement for limiting the intensity of the magnetic field leaked into the space surrounding an operating induction heating/cooking apparatus by confining the field by means of substantially closed, high relative permeability, flux shaping means.
Yet another object is the provision of an induction cooking arrangement having a relatively low reluctance path for flux linking the cooking utensil to the induction cooking coil.
A further object is the provision of a metal trim frame for supporting a ceramic induction cooking plate in an opening in a horizontal support surface, the cooking plate being provided with a metallic layer on its surface to form a low reluctance flux path between a cooking utensil supported on the plate and the frame to thereby eliminate a main source of leakage flux from the unit.
These and other objects are accomplished according to the principle of the invention by provision of an induction heating apparatus having a cooktop including a plurality of induction surface heating units. The cooktop comprises a horizontally disposed planar metal support surface having a plurality of openings therein. A ceramic smooth-top plate is supported in each of the openings and adapted to support a cooking utensil thereon. An induction heating coil is supported subjacent the ceramic plate in a position to generate a magnetic field which passes through the plate to link the cooking utensil. Each plate is supported in the openings by a metallic trim frame and a conductive layer is provided on the plate, the frame and layer combining to provide a low reluctance flux path for flux generated by the coil and linking the utensil, the low reluctance path operating to reduce the magnetic flux leaked into the space surrounding the heating apparatus during operation.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details of the present invention and many additional advantages of this invention will be apparent from a detailed consideration of the remainder of this specification and the accompanying drawings in which:
FIG. 1 is a generalized perspective view of an induction heating/cooking apparatus embodying the principles of the invention; and
FIG. 2 is an illustrative vertical cross section showing the relationship in an induction heating/cooking unit between the cooking utensil, the ceramic insert which provides cooking support surface, the induction heating coil, and the metal cooktop, in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and initially to FIG. 1, the induction heating/cooking apparatus generally designated 10 includes an upstanding substantially box-like metal body 12 having a substantially horizontal cooktop 14. The cooktop 14 includes four surface cooking units 20 located at the right rear, left rear, right front and left front positions. An upstanding control and display panel 16 is located at the rear of the cooktop 14. The control and display panel in a conventional manner provides a means whereby a user of the cooking apparatus may control the cooking process or any or all of the surface cooking units 20 by utilizing suitable manually-actuatable controls associated with the various cooking units. Suitable display devices may also be included on the panel 16 to indicate to the user the current operational state of these cooking units, such as temperature, cooking time, etc. A hinged oven door 18 having a suitable handle 19 for opening and closing thereof provides access to an oven cooking area (not shown).
The cooking units 20 are generally of the induction heating type, and FIG. 2 shows a cross sectional view of a preferred embodiment of one of the units 20 utilizing the principles of the invention, with a cooking utensil 22 resting thereon, the other cooking units being substantially identical in construction to the one shown.
Referring to FIG. 2, it is seen that each cooking unit 20 comprises a support plate 21 on which a suitable cooking utensil 22 is adapted to rest. The utensil 22 is preferably, but not necessarily, made of a ferromagnetic material, such as iron or stainless steel, so as to heat up more efficiently when subjected to a changing magnetic field of the type used in induction heating units.
Plate 21 is made of a material which is electrically insulating and thermally transmissive as well as being highly wear and thermal shock resistant, and resistant to the physical and chemical attacks of foods and liquids which may come in contact with the plate during the cooking process. Such materials are usually milk-white or black in color, opaque, and sold under the trademarks "PYROCERAM", "CER-VIT", and "HERCUVIT". The plate 21 is also non-ferromagnetic in nature so as to allow the flux generated by the induction heating coil to pass therethrough into linking relationship with the cooking utensil 22. While the term glass-ceramic or crystalline glass will be used throughout in referring to the material which comprises plate 21, it should be understood that the invention encompasses other materials with similar characteristics, such as quartz, high silica glass, high temperature glasses and different ceramic materials. While the plate 21 is preferably circular in shape, other configurations may be used satisfactorily.
The plate 21 has deposited thereon a thin, ring-shaped, conductive layer 27 covering the outermost peripheral portions of the plate 21. The layer 27 is preferably ferromagnetic and its purpose and operation will be addressed in greater detail hereinafter.
The circular plate 21 is supported by a circular metal trim frame 23 of thin sheet stock of stainless steel or like material. The trim frame 23 includes a flat annular rim 24 adjacent its outer periphery which is adapted to overlie and rest on a generally flat horizontal sheet metal surface 25 forming the major portion of the cooktop 14. The trim frame 23 also includes a bifurcated formation on its inner periphery facing the plate 21 which has inwardly extending arms 31 and 32. The top arm 31 contacts the top surface of the conductive layer 27, and the bottom arm 32 in turn supports on annular lip 33 of a pan-like member 34 in which is supported an induction heating coil 35. While the trim frame 23 is preferably circular, it would, of course, conform to whatever shape is selected for the plate 21. The trim frame 23 is thus seen to support both the cooking plate 21 and the induction cooking coil 35 from the horizontal surface 25.
Another pan-like member 40 which is generally U-shaped in cross section serves to provide additional support for the cooking unit. Specifically, the member 40 is provided with an outer rim 41 which extends radially a sufficient distance to rest on an inwardly extending flange 42 of the support surface 25 located below the cooktop surface. The upper surface of the rim 41 in turn abuts the bottom wall of the pan 35 and is attached thereto, as by welding.
The induction coil 35 preferably has a flat pancake-like shape and is mounted such that the central axis 36 of the coil, if extended upwardly through the cooking plate 21, passes through the approximate geometric center of the cooking area on which the pan 22 is to be located. The surface cooking unit also includes an inverter circuit (not shown) well known in the art, which is coupled to the coil 35 for producing an ultrasonic magnetic field linking the cooking utensil 22. The utensil 22 acts as a single turn, shorted secondary to be heated by the energy contained in the field. In a known manner, the field is produced by causing bi-directional current pulses in the coil 35.
The cooking unit 20 is thus adapted, by virtue of the formation of the pan members 40, 34 and the trim frame 23, to be inserted as a unit from above a circular opening in the support surface 25. Suitable connections are, of course, provided to couple the electrical power supply to drive the cooking unit to the induction coil 35 when in place.
In addition to providing physical support for the cooking unit 20, the pan 34, trim frame 23, and layer 27 cooperate with the utensil 22 to form a flux shaping means for the magnetic field generated by coil 35. More specifically, the high relative permeability materials from which these elements are made serve to shape and confine the flux generated by the coil 35 during the induction heating process and to thereby reduce undesirable leakage of magnetic flux into the surrounding space.
In contrast to this arrangement, prior art induction systems are much less effective in preventing flux leakage because of the high reluctance gaps in the flux-shaping paths, notably a gap 51 between the utensil and the flux shaping means which supports the induction coil. More specifically, in the prior art, since the cooking plate on which the utensil rests is a large continuous glass surface which extends far beyond the cooking area, a high reluctance gap 51 is presented between the utensil 22 and the flux shaping conductive support for the induction coil, which is located below the cooking surface. Thus, the magnetic circuit for flux linking the cooking utensil with the flux shaping means adjacent the heating coil includes a high reluctance gap 51, causing fringing or leakage of flux into the surrounding space.
By the addition of the conductive layer 27, as shown in FIG. 2, a uniform low reluctance flux path is provided between the utensil 22 and the flux shaping members which surround the inductive coil. Thus, with a utensil 22 in place on the plate 27 and positioned as shown, the flux generated by the coil 35 is confined in a substantially closed area bounded by the members 34, 23, layer 27 and the bottom wall of the utensil 22. This substantially closed low reluctance flux shaping system thereby more effectively confines the magnetic field and reduces unwanted leakage emission.
While the above-noted closed surface flux confining arrangement has been illustrated as being accomplished by means of a metal trim frame 23 which couples the field shaping means below the plate (pan 34) with the field shaping means above the plate (layer 27) it is possible, though less practical, to utilize a large continuous ceramic sheet which extends beyond a given cooking unit area, but which incorporates a low reluctance conductor passing through the sheet to serve as a link to magnetically couple the utensil to the flux shaping means below the sheet.
Additionally, while the layer 27 in FIG. 2 as shown is higher than the top surface of the plate 21, it is equally possible to provide a recess in the glass surface in the area which carries this layer. With this arrangement, the layer 27 would be flush or level with the top surface of the cooking plate 21.
Other modifications of this invention will occur to those skilled in the art; therefore, it is to be understood that this invention is not limited to the particular embodiments disclosed but that it is intended to cover all modifications which are within the spirit and scope of the invention as expressed in the accompanying claims.
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An induction heating apparatus having a cooktop including a plurality of induction surface heating units. The cooktop comprises a horizontally disposed planar metal support surface having a plurality of openings therein. A ceramic smooth-top plate is supported in each of the openings and adapted to support a cooking utensil thereon. An induction heating coil is supported subjacent the ceramic plate in a position to generate a magnetic field which passes through the plate to link the cooking utensil. Each plate is supported by a metallic trim frame, which abuts a conductive layer on the plate, the frame and layer combining to provide a low reluctance flux path, the low reluctance path operating to reduce the magnetic flux leaked into the space surrounding the heating apparatus during operation thereof.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to provisional patent application Ser. No. 60/234,588, filed Sep. 22, 2000, incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with United States government support awarded by the following agency: NIH 9723830. The government has certain rights in this invention.
BACKGROUND OF THE INVENTION
Cell physiology is characterized by the interplay of numerous metabolic pathways and processes. Integration is essential to create a metabolism that is robust, yet adaptable to complex environmental conditions, such as growth in the presence or absence of oxygen. Although aerobic respiration provides a substantial energetic advantage, it necessarily generates toxic oxygen species that can damage macromolecules (Gonzalez-Flecha, B. and Demple, B., J. Biol. Chem. 270:13681-7, 1995; Imlay, J. A. and Fridovich, I., J. Biol. Chem. 266:6957-65,1991. For example, superoxide radicals (O 2 − ) can oxidize labile [4Fe-4S] to inactive [3Fe-4S] clusters (Flint, D. H., et al., J. Biol. Chem. 268:22369-76, 1993; Kuo, C. F., et al., J. Biol. Chem. 262:4724-7,1987). Such oxidation has at least two detrimental consequences, inactivation of enzymes containing [Fe—S] clusters (Flint, D. H., et al., supra, 1993; Gardner, P. R. and Fridovich, I., Arch. Biochem. Biophys. 284:106-11, 1991; Gardner, P. R. and Fridovich, I., J Biol Chem 266:1478-83,1991; Gardner, P. R. and Fridovich, I., J. Biol. Chem. 266:19328-33,1991), and increased DNA damage (Imlay, J. A. and Linn, S., Science 240:1302-9, 1988; Keyer, K. and Imlay, J. A., Proc. Natl. Acad. Sci . USA 93:13635-40,1996). DNA damage results from ferrous ions, released during the oxidation of [4Fe-4S] clusters. These ions participate in Fenton chemistry (Fe(II)+H 2 O 2 +H+→Fe(III)+H 2 O+OH●), with the hydroxyl radicals damaging DNA and other macromolecules (Keyer, K. and Imlay, J. A., supra, 1996; Liochev, S. I. and Fridovich, I., Free Radic. Biol. Med. 16:29-33, 1994; Srinivasan, C., et al., J. Biol. Chem. 275:29187-92, 2000). It would not be surprising that many cellular anomalies caused by increased superoxide concentration result from oxidization of [Fe—S] clusters (Keyer, K. and Imlay, J. A., supra, 1996).
Several systems exist to reduce the potential for damage by superoxide radicals (Storz, G. and Imlay, J. A., Curr. Opin. Microbiol. 2:188-94, 1999). In general, these systems either prevent the damage from occurring or repair it. The Sox regulon is a good example of the former. This regulon includes a number of genes that are induced under conditions of oxidative stress via the SoxRS regulatory system (Hidalgo, E. and Demple, B., Embo J. 16:1056-65,1997; Gaudu, P., et. al., J. Biol. Chem. 272:5082-6,1997; Liochev, S. I., et al., J. Biol. Chem. 274:9479-81, 1999). One component of this system is the superoxide dismutase enzymes (SOD, EC 1.15.1.1) that catalyze the formation of molecular oxygen and hydrogen peroxide from two superoxide radicals (O 2 − +O 2 − +2H + →O 2 +H 2 O 2 ). The resulting hydrogen peroxide (H 2 O 2 ) is a substrate for catalase (hydroperoxidase) enzymes (EC 1.11.1.6,1.11.1.7) that convert it to water and molecular oxygen. A distinct way of protecting [Fe—S] clusters is shown by the FeSII protein of Azotobacter vinelandii . The FeSII, or Shetna protein, forms a complex with nitrogenase under periods of high oxygen exposure, thus protecting the essential [Fe—S] cluster from oxidation (Lou, J., et al., Biochemistry 38:5563-71, 1999; Shethna, Y. I., et al., Biochem. Biophys. Res. Commun. 31:862-8,1968).
In addition to eliminating superoxide per se, mechanisms to repair damage incurred by the superoxide radicals have evolved. This second strategy includes multiple repair systems that are specific for DNA damage (McCullough, A. K., et al., Annu. Rev. Biochem. 68:255-85,1999; Cadet, J., et al., Mutat. Res. 462:121-8, 2000; Boiteux, S. and Radicella, J. P., Biochimie 81:59-67,1999). The DNA glycosylase MutY, which itself contains an [Fe—S] cluster (Michaels, M. L., et al., Nucleic Acids Res. 18:3841-5, 1990; Porello, S. L., et al., Biochemistry 37:6465-75, 1998), recognizes the mispairing of an oxidized guanine base (8-oxo-guanine) with adenine and cleaves the relevant adenine (Michaels, M. L., et al., Biochemistry 31:10964-8, 1992). This cleavage product becomes the target for additional repair enzymes that prevent the generation of a G●C to T●A transversion mutation.
Another example involves direct repair of oxidized [Fe—S] clusters in vivo. The enzyme paradigm for the majority of studies addressing the in vivo and in vitro reconstitution of [Fe—S] clusters is aconitase (Acn, EC 4.2.1.3) (Kennedy, M. C. and Beinert, H., J. Biol. Chem. 263:8194-8, 1988; Gardner, P. R. and Fridovich, I., J. Biol. Chem. 267:8757-63,1992; Gardner, P. R. and Fridovich, I., Arch. Biochem. Biophys. 301:98-102, 1993). Part of the catalytic [4Fe-4S] center in aconitase is exposed to the solution and is not sequestered by the enzyme; thus the enzyme is sensitive to attack by superoxide (Gardner, P. R and Fridovich, I., supra, 1992; Beinert, H., et al., Chem. Rev. 96:2335-2373, 1996). Although extensive work has been preformed to characterize in vitro reactivation of oxidized [Fe—S] clusters (Kennedy, M. C. and Beinert, H., supra, 1988), the participants in [Fe—S] cluster repair in vivo are less well defined (Gardner, P. R. and Fridovich, I., supra, 1993). The benefit of in vivo repair of [Fe—S] clusters is at least two fold, first the restoration of enzyme activity, and second, the decrease of free iron.
Several experiments have suggested that glutathione (GSH) is involved in the in vivo repair and possibly biosynthesis, of the [Fe—S] center in aconitase (Gardner, P. R. and Fridovich, I., supra, 1993). When Escherichia coli strains in vivo were challenged with oxygen total aconitase activity decreased, as expected for an enzyme with a labile [Fe—S] cluster. However, when the oxygen challenge was removed, unlike the wild-type strain, gshA (encodes y-I-glutamyl-I-cysteine synthetase, EC 6.3.2.2) mutants were unable to regain aconitase activity in the absence of protein synthesis (Gardner, P. R. and Fridovich, I., supra, 1993).
Further, gshA mutants of E. coli have reduced total aconitase activity (Gardner, P. R. and Fridovich, I., supra, 1993).
Needed in the art is an improved method of protecting cells and oxygen-labile enzymes from superoxide damage.
BRIEF SUMMARY OF THE INVENTION
We disclose herein that increased levels of the YggX protein reverse several metabolic defects attributed to a lack of GSH, increase resistance to superoxide stress, and decrease the spontaneous mutation frequency in S. enterica . The phenotypic consequences of increased YggX protein are consistent with a model in which this protein protects labile [Fe—S] clusters from oxidative damage.
In one embodiment, the present invention is a method of reducing superoxide damage to a cell, comprising the step of engineering the cell to produce more than the native amount of the YggX protein or its homolog, wherein the cells are rendered more resistant to oxidative damage. A preferred method additionally comprises the step of analyzing the protein to determine that the cells are rendered more resistant to superoxide damage.
Another embodiment of the present invention comprises increasing the resistance of oxygen-labile proteins to oxidative damage, comprising the step of co-expressing the oxygen-labile protein with the YggX protein or a homolog of the YggX protein. Preferably, one additionally examines the oxygen-labile protein to determine the amount of superoxide damage.
Another embodiment of the present invention comprises a method of screening compounds for antibiotic properties, comprising the step of examining a test compound's ability to effect YggX activity or the activity of a YggX homolog, wherein decreased YggX activity indicates that the compound is a likely candidate as an antibiotic.
It is an object of the present invention to protect cell and oxygen-labile proteins from superoxide damage.
Other objects, features and advantages of the present invention will become apparent to one of skill in the art after review of the specification, claims and drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 . Physical parameters of yggX and its gene product. (A) Alignment of YggX homologs. (B) Operon structure of mutY/yggX in E. coli and S. enterica LT2. Promoters were mapped by Gifford and Wallace in E. coli (Gifford, C. M. and Wallace, S. S., J. Bacteriol. 181:4223-36,1999).
FIG. 2 . Increased levels of YggX protein in yggX* mutant. Western blot analysis was preformed according to Harlow and Lane (Harlow, E. and Lane, D. (1988) Antibodies (Cold Spring Harbor Laboratory, USA). Proteins were visualized using alkaline phosphatase conjugated to anti-rabbit secondary antibody (Promega, Madison, Wis.). Lanes A, B and C were loaded with crude cell-free extracts (1 μg protein) from strains DM5104, DM5105 (yggX*) and DM5647 (yggX::Gm), respectively. Lane D was loaded with 1 ng purified YggX.
FIG. 3 . The yggX* mutation does not increase MNNG resistance of gshA mutants. Strain LT2 was grown in LB with (▾) and without (Δ) 60 μM MNNG. Both gshA (◯) and gshA yggX* (●) mutant strains were grown in LB with 60 μM MNNG.
FIG. 4 . The yggX* mutation increases resistance of S. enterica to PQ. Panel A shows growth of gshA (◯) and gshA yggX* (●) mutant strains in LB with 4 μM PQ.
Panel B shows growth of LT2 (Δ) and yggX* (▾) strains in LB with 40 μM PQ.
FIG. 5 . yggX* does not require soxR to mediate resistance to PQ. Strains LT2 (♦), soxR (⋄) and soxR yggX* (▴) were grown in LB with 4.0 μM PQ.
FIG. 6 . Model showing how YggX protects S. enterica from oxidative damage. The result of superoxide attack on [Fe—S] clusters is depicted. We hypothesize that YggX is able to block oxidative damage to labile clusters and thus prevents the normal downstream consequences of such oxidation.
DETAILED DESCRIPTION OF THE INVENTION
In brief, the present invention involves the use of YggX, a protein identified from Salmonella enterica Serovar Typhimurium, or the homolog of this protein to protect cells or oxygen-labile enzyme from oxidated damage. By “homolog” we mean a protein with a function substantially identical to the Salmonella typhimurium YggX protein with at least a 45%, preferably 55%, amino acid identity. FIG. 1A compares the YggX homologs of various bacterial species. Of the 17 invariable amino acids, a homolog suitable for the present invention will comprise at least 14 and preferably all 17. We have compared a number of sequences and have found that 14 of the residues are invariant throughout all sequences examined. The conserved motif of suitable homologs is
MXRXXXCXXX XXXXXXXXXX XXPXXXGXXX XXXXXXXXWX XWXXXQTXLX NEXXLXXXXX XXRXX (SEQ ID NO: 1), wherein X is any amino acid.
These 14 residues are represented by dark shading in FIG. 1A . A preferred sequence of the present invention will comprise these 14 invariant residues and will be approximately the same size as the YggX protein.
In one aspect of the present invention, one would overexpress the YggX protein or its homolog in a cell to provide resistance to superoxide damage. (By “overexpress”, we mean that the protein will be expressed at greater than native levels.) One would preferably first amplify the YggX gene from the bacterial chromosome and ligate the gene into a standard expression vector suitable for the strain to be protected. One would use the expression of the YggX gene and, preferably, examine the strain to determine resistance to oxidative damage.
Resistance to oxidative damage would preferably be determined by the ability of the cell to grow in an increased concentration of super oxide producing compounds (e.g. paraquat) compared to the cell with lower levels of YggX protein.
In another embodiment of the present invention, one would co-express the YggX protein or its homolog with an oxygen-labile protein, preferably one with an iron sulfur cluster center. In this manner, one would protect the particular protein from superoxide damage. If one wished to co-express YggX to stabilize an oxygen-labile protein, one would first amplify the yggX gene from a bacterial chromosome that contains a homolog using standard PCR techniques. One would then ligate the yggX gene into a standard expression vector and transform the yggX expression vector into a strain that can express the oxygen-labile protein of interest. When inducing the strain to express the protein of interest, one would also induce expression of the yggX gene. The “stabilization” of oxygen-labile proteins would preferably be measured by detecting increased activity of an oxygen-labile protein or by recovering increased yield of the active protein. Preferred oxygen-labile proteins are those containing at least one [FE] cluster.
While we have performed experiments thus far in bacterial cells we anticipate a similar mechanism of protection to occur with YggX in other cell types, including yeast, mammalian and plant cells. This expectation is due to the similarity of structure, function and oxygen lability of [Fe—S]-containing proteins in each of these cell types.
One could obtain the YggX protein through standard molecular biology techniques and reference to Gralnick and Downs, Proc. Natl. Acad. Sci. 98(14):8030-8035, 2001, incorporated by reference. Applicants note that the amino acid sequence of the E.Coli YggX is listed at GenBank accession number AAC75999 (SEQ ID NO:11).
In another aspect of the present invention, one would use the YggX protein or its homologs as the target for antibiotics. In one embodiment, one would examine test compounds to determine whether the compound affected the activity of the YggX protein. Successful compounds would make excellent candidates for antibiotics.
Successful compounds that affect the activity of YggX could be identified as those that reverse the growth advantage (i.e., increased resistance to paraquat) that is allowed by increased levels of YggX protein. One would develop an in vitro assay fro YggX, and these compounds would be expected to alter the kinetic parameters YggX in the assay.
EXAMPLES
We disclose herein that elevated levels of the YggX protein increase the resistance of Salmonella enterica to superoxide stress, reverse enzymatic defects attributed to oxidized [Fe—S] clusters, and decrease the spontaneous mutation frequency. The data are consistent with a model in which YggX protects protein [Fe—S] clusters from oxidation.
Materials and Methods
Strains, media and DNA manipulations. Strains used were derivatives of S. enterica Serovar Typhiumurium strain LT2. Media, antibiotics, and insertion nomenclature have been described previously (Gralnick, J., et al., J. Bacteriol. 182:5180-7, 2000). All chemicals were purchased from Sigma Chemical Co.
Enzymes for DNA manipulations were purchased from Promega and used as per the manufacturer's instructions. Sequencing was carried out by the University of Wisconsin Biotechnology Center. PCR amplification of S. enterica yggX used E. coli ORFmers (b2962-A, b2962-C) with conditions specified by the manufacturer (Sigma-Genosys).
Genetics i) Transduction. The methods of transduction using P22 (HT105/1, int-201) (Schmieger, H., Mol. Gen. Genet. 119:75-88, 1972) and purification of transductants has been described (Downs, D. M., J. Bacteriol. 174:1515-21, 1992).
ii) Isolation of mutants overexpressing YggX (yggX*). Cells from an overnight nutrient broth (NB) culture were pelleted, washed twice with NaCl (85 mM), and aliquots plated on minimal glucose medium. Colonies arose after 2-3 days of 37° C. incubation. A Tn10d (Cm) insertion (Way, J. C., et al. Gene 32:369-79, 1984) linked to the causative mutation was identified by standard genetic techniques (Kleckner, N., et al. J. Mol. Biol. 1 16:125-59, 1977).
iii) Identification of yggX locus. Genomic DNA from a suppressed gshA strain was partially digested with Sau3A, ligated into vector pSU19(Cm), and the resulting DNAs were electroporated into LT2 cells. Electroporants were selected for Cm R and screened for increased resistance to paraquat PQ (100 μL 0.1% PQ spread on a NB plate). Plasmid DNA was isolated, electroporated into strains DM271 (apbE) and DM4620 (gshA) and prototrophy scored. One clone, pPQR4 ( FIG. 1 ), satisfied all requirements, and was used further.
iv) Generation of chromosomal yggX insertion. Plasmid pYGGX3A::Gm was transduced into a polA-deficient strain (DM3961). The transduction was allowed to proceed for 1 hour, cells were then washed twice in LB+5 mM EGTA and incubated at room temperature overnight prior to spreading onto NB/Gm plates. Colonies that arose on NB/Gm plates were screened for Cm S , indicating loss of the parent plasmid by a double crossover event. The Gm R cassette from Gm R Cm S strains was transduced into wild type LT2; the insertion in yggX was confirmed by PCR amplification.
v) Strain construction. A soxR deletion strain of Escherichia coli (DJ901) was obtained and the marker (zjc-2204::Tn10 (Km)) linked to the deletion (Greenberg, J. T., et al., Proc. Nat. Acad. Sci. USA 87:6181-5,1990) was transduced into S . enterica LT2 via a mutS intermediate as described (O'Brien, K., et al., Gene 11813-9,1992; Beck, B. J., et al., J. Bacteriol. 179:6504-8,1997). Transductants were scored for the ΔsoxR901 allele (sensitivity to 4 μM paraquat, (PQ)). An isogenic pair of strains with (DM5317) and without (DM5319) the ΔsoxR901 allele was constructed. The presence of the yggX* mutation in relevant strains was confirmed by backcross into a gshA strain (DM4620).
vi) Nutritional requirements. Nutritional requirements were tested with solid medium, soft agar overlays and growth curves in micro-titer plates (Petersen, L., et al., Genetics 143:37-44, 1996; Christian, T. and Downs, D. M., Can. J. Microbiol. 45:565-72, 1999).
vii) Spontaneous mutation frequency. Cultures were grown by shaking overnight in LB at 37° C. Aliquots (100-200 μl) were plated on solid LB media containing 100 μg/ml rifampacin, and incubated overnight at 37° C. In the case of d-cycloserine resistance, cultures were grown overnight in defined medium. Aliquots (10-100 μl) were plated on minimal glucose plates containing 0.2 mM d-cycloserine (0.2 M stock in phosphate buffer pH 8.0), and incubated overnight at 37° C. Colony-forming units (CFUs) were determined by plating on non-selective media.
Enzyme assays. i) Aconitase. Aconitase activity was assayed in cell-free crude extracts by the protocol of Gruer and Guest (Gruer, M. J. and Guest, J. R., Microbiology 140:2531-41,1994), as modified by Skovran (Skovran, E. and Downs, D. M., J. Bacteriol. 182:3896-903, 2000). Specific activity was described in Units/mg protein where a unit was the change in absorbance at 240 nm per minute. Protein concentration was determined by the Bradford Assay (Bradford, M. M., Anal. Biochem. 72:248-54,1976).
ii) Superoxide Dismutase (EC 1.15.1.1). SOD assays were modified from McCord and Fridovich (McCord, J. M. and Fridovich, I., J. Biol. Chem. 244:6049-55, 1969). Cultures (5 mL of LB grown overnight at 37° C.) were washed once with 3 mL 50 mM KH 2 PO 4 /0.1 mM EDTA, then resuspended in 1 mL of this buffer. Cells were kept on ice and sonicated 3 times 10 seconds (0.5 second pulses, power set to 3) using a Sonic Dismembrator 550 (Fischer Scientific). Extracts were centrifuged to remove cell debris and unbroken cells, and kept on ice until assayed. A unit of SOD activity was as described (McCord, J. M. and Fridovich, I., supra, 1969).
YgqX overexpression and purification. The yggX gene was cloned into the Ndel and Smal sites of the pTYB2 expression vector (New England Biolabs) contained in the IMPACT T7 Kit. The resulting plasmid, pJAG100, was electroporated into strain BL21 (γDE3). Overexpression and purification were performed per manufacturer's recommendations, with the exception that the dithiothreitol (DTT) concentration used during the on-column cleavage step was 50 mM. Protein was concentrated using an Ultrafree-15 centrifugal filter device (Millipore Corporation) with a 5K MW cutoff. Anti-YggX polyclonal rabbit antibodies against purified YggX were generated at the University of Wisconsin Animal Care Unit.
Results
A suppressor of gshA mutant phenotypes. We recently demonstrated that gshA mutants of Salmonella typhimrium serovar Typhimurium strain LT2 are thiamine auxotrophs (Gralnick, J., et al., supra, 2000). When a gshA mutant strain was incubated on minimal glucose plates for 2-3 days, colonies arose at a frequency of ˜10 −5 . Genetic analyses of 10 independent colonies demonstrated that prototrophic growth resulted from a single lesion. An insertion (zgf-8077::Tn10d(Cm)) was 80% linked by P22 transduction to the causative mutation in each of the 10 revertants. The suppressing allele was designated yggX*, to be consistent with annotation of the E. coli genome.
An intact yggX locus is required for suppression. A plasmid library was generated using genomic DNA from a gshA yggX* double-mutant strain (DM5015). Assuming the yggX* mutation was dominant, clones were screened for ability to confer PQ resistance (see below), and prototrophic growth to strain DM4620 (gshA). One such plasmid (pPQR4) is diagrammed in FIG. 1 , and was further characterized. Sequence analysis determined that plasmid pPQR4 contained two full genes (yggx, mItC), and part of a third (mutY). Since additional independent clones also carried yggX, the involvement of this gene in prototrophic growth was pursued. A DNA fragment containing yggX and reduced flanking sequences was PCR-amplified from pPQR4 and used to generate plasmid pYGGX3A ( FIG. 1 ). This plasmid conferred the same growth phenotype as pPQR4, establishing the sufficiency of the yggX gene for suppression.
To investigate the role of yggX in the growth phenotype, a targeted null mutation was generated. A cassette encoding gentamycin resistance (Schweizer, H. D., Biotechniques 15:831-4, 1993) was engineered into a unique Bg/II site in the yggX coding sequence on plasmid pYGGX3A. The resulting plasmid, pYGGX3A::Gm, failed to restore growth of strain DM4620 (gshA) on minimal glucose medium. When the chromosomal yggX::Gm insertion was transduced into strain DM5015 (yggX* gshA), the suppression of the thiamine requirement was lost. We concluded that an intact yggX locus was required for the phenotypic suppression caused by a yggX* mutation. No nutritional requirement was detected for the single yggX null mutant (data not shown).
Increased expression of yggX is sufficient for phenotypic suppression of gshA mutants. Three results led to the conclusion that the yggX* mutation results in increased levels of YggX protein that cause the phenotypes attributed to this mutation. First, there were no differences in the yggX coding sequence between wild-type and yggX* strains. Second, ORFmers were used to amplify the yggX coding sequence from wild-type and yggX* mutant strains and generate plasmids containing only the yggX coding region in each of two orientations. Only the two plasmids with inserts properly oriented with respect to the plasmid encoded lac promoter restored prototrophic growth of the gshA mutant.
Third, Western-blot analyses of cell-free extracts showed that strain DM5105 (yggX*) had increased levels of YggX protein (11 kDa) compared to the isogenic strain DM5104 ( FIG. 2 ). In fact, YggX was not detectable in the wild-type strain by this assay. The above results demonstrated that increasing the levels of YggX was sufficient to cause the phenotypes associated with the yggX* mutation and they were consistent with the yggX* mutation affecting expression of yggX.
The yggX gene is located at minute 66 on the E. coli and S. enterica chromosomes. In a number of organisms, yggX is located adjacent to mutY (encoding adenine DNA glycosylase), and at least in E. coli , these genes appear to be co-transcribed (Gifford, C. M. and Wallace, S. S., J. Bacteriol. 181:4223-36, 1999). The gene organization of mutY and yggX appears to be conserved in at least 17 out of the 23 eubacteria. We have not found yggX sequences in any archeal or eukaryotic genome sequences available in the GenBank Database at NCBI.
Increased level of YqgX does not act by increasing the cellular levels of free thiols. Inactivation of gshA results in loss of GSH, the predominant free thiol in the cell (Apontoweil, P. and Berends, W., Biochim. Biophys. Acta 399:10-22, 1975). Since the phenotypes of a gshA mutant must be explained in the context of this loss, it was conceivable that the phenotypic suppression by yggX* could be due to either gshA-independent formation of GSH, or elevation of a distinct free-thiol pool. The results of two experiments eliminated both of these possibilities. First, GSH levels of 14.0 pmol/mg wet weight were detected in wild-type strain (LT2) using a glutathione cycling assay (Anderson, M. E., Methods Enzymol. 113:548-55, 1985), yet no GSH (<0.1 pmol) was detectable in either gshA or gshA yggX* mutant strains (DM5014 and 5015, respectively). Second, the yggX* mutation did not alter the sensitivity of a gshA mutant to N-methyl-N′-nitro-N-nitrosguanidine (MNNG). MNNG is a common mutagen whose toxicity is accelerated by the presence of free thiols in the cell (Lawley, P. D. and Thatcher, C. J., Biochem. J. 116:693-707,1970). Growth analyses were preformed in the presence of 60 μM MNNG and the results are presented in FIG. 3 . As expected, strain DM5014 (gshA) was significantly more resistant to MNNG than wild-type strain LT2 (Kerklaan, P., et al., Mutat. Res. 122:257-66, 1983), and the yggX* mutation had no deleterious affect on this resistance. In fact the gshA yggx* double mutant (DM5015) appeared to have a slightly increased growth rate. A general stimulation of growth rate was obseryed in several strains containing the yggX* mutation or the overexpression plasmid, and was attributed to the general effect of increased levels of YggX on distinct areas of metabolism described below. The resistance of gshA yggX* double mutants to MNNG suggested that an increased level of YggX did not elevate the pool size of a free thiol.
The breadth of phenotypes suppressed by increased levels of YggX suggests a role for this protein in protecting [Fe—S] clusters. Mutants defective in gshA belong to a recently defined class of thiamine auxotrophs that share several phenotypic similarities (Gralnick, J., et al., supra, 2000; Skovran, E. and Downs, D. M., supra, 2000) including a requirement for the thiazole moiety of thiamine that can be eliminated by anaerobic growth. It has been proposed that this defect reflects an inability to repair the oxidized [Fe—S] cluster in the ThiH biosynthetic enzyme (Gralnick, J., et al., supra, 2000). Although the function of their gene products has not been determined, lesions in apbC (Petersen, L. A. and Downs, D. M., J. Bacteriol. 179:4894-900, 1997) and apbE (Beck, B. J. and Downs, D. M., J. Bacteriol. 180:885-91, 1998; Beck, B. J. and Downs, D. M., J. Bacteriol. 181:7285-90, 1999) result in a thiamine phenotype similar to that caused by a gshA mutation. The effect of the yggX* mutation on thiamine-independent growth in these mutant strains was quantified, and data from representative experiments are shown in Table 1. The data showed that the requirement for thiamine was eliminated by a yggX* mutation in a strain defective in gshA, apbC, or apbE (Table 1, lines 2-7). These results were consistent with thiamine synthesis in these mutant strains being disrupted by a similar mechanism.
TABLE 1
yggX* mutation eliminates thiamine requirement of gshA mutants
Growth rate, μ
Line
Strain
Relevant genotype
Minimal
Min + Thi
1
LT2
Wild type
0.45
0.47
2
DM5014
gshA
0.11
0.32
3
DM5015
gshA yggX*
0.46
0.35
4
DM5784
apbE
0.09
0.31
5
DM5783
apbE yggX*
0.44
0.42
6
DM1774
apbC
0.20
0.37
7
DM1773
apbC yggX*
0.46
0.45
Specific growth rate was determined by using μ = In(X/X 0 )/T, where X is Abs 650 during the log portion of the growth curve and T is time. Numbers shown are representative of at least two experiments.
Mutations in the isc gene cluster of S. enterica (Skovan, E. and Downs, D. M., supra, 2000) and E. coli (Schwartz, C. J., et al., Proc. Natl. Acad. Sci. USA 97:9009-14, 2000; Lauhon, C. T. and Kambampati, R., J. Biol. Chem. 275:20096-103, 2000) cause a number of metabolic phenotypes, two of which are relevant here. A polar mutation in iscA caused a requirement for thiazole similar to that described for the class of mutants discussed above (Skovan, E. and Downs, D. M., supra, 2000). This requirement was eliminated by the presence of either the yggX* mutation or plasmid pYGGX3A (data not shown). Further, the nicotinic acid requirement generated by lack of the iscS gene was eliminated by the overexpression of YggX (Skovan, E. and Downs, D. M., supra, 2000), unpublished results). The nicotinic acid requirement can be traced back to a reduced activity of NadA (quinolinic synthetase) (Skovan, E. and Downs, D. M., supra, 2000; Zhu, N. in Biology (Thesis, University of Utah, Salt Lake City, 1990, an enzyme that also contains an oxygen-labile [Fe—S] center (Gardner, P. R. and Fridovich, I., supra, 1991).
The emerging correlation between increased YggX levels and activity of [Fe—S] proteins prompted us to address aconitase activity. In both E. coli (Gardner, P. R. and Fridovich, I., supra, 1993) and S. enterica (Gralnick, J., et al., supra, 2000), gshA mutants have reduced total aconitase activity. This loss in activity was suggested to reflect an inability to repair the oxidized [Fe—S] center of Acn in the absence of GSH (Gardner, P. R. and Fridovich, I., supra, 1993). The specific activity of aconitase in cell-free extracts of wild-type, gshA and gshA yggX* mutant strains was 3.50±0.32, 1.23 ±0.22, and 3.66+0.23 Units/mg protein, respectively.
Increased levels of YggX restored activity of at least two enzymes when assayed nutritionally (ThiH, NadA) and one when assayed biochemically (Acn). The ability of the yggX* mutation to completely restore Acn activity makes it feasible that suppression of the nutritional requirements reflects a significant change in the relevant enzyme activities. Experiments below identified additional metabolic consequences of increased levels of YggX, all of which could be accounted for by a model in which YggX was either limiting oxidation of [Fe—S] centers and/or facilitating their repair.
Increased levels of YggX result in soxR-independent resistance to superoxide. Strains carrying the yggX* mutation, or the expression plasmids described above, displayed increased resistance to superoxide. Supplementing the growth medium with the redox-cyling herbicide paraquat (PQ) increased the concentration of superoxide (Hassan, H. M., Methods Enzymol. 105:523-32, 1984). FIG. 4 illustrates the effect of the yggX* mutation on the growth of four strains in the presence of PQ. Data in FIG. 4A show that wild-type S. enterica grew slowly in the presence of 40 lM PQ, and that a yggX* mutation restored rapid growth. A gshA mutant was sensitive to the presence of 4 μM PQ, as shown in FIG. 4B (Gralnick, J., et al., supra, 2000), and the yggx* mutation improved growth, restoring it to a wild-type rate. In other experiments using phenazine methosulfate (PZ, 16 μM) as the generator of superoxide, similar trends were seen. In a representative experiment, the specific growth rates of a gsha (DM5014) and a gshA yggX* mutant strain (DM5015) in LB containing PZ were 0.15 and 0.51, respectively.
Growth in PQ induces expression of genes in the soxRS regulon, currently the best understood system to combat superoxide stress (Liochev, S. I., et al., supra, 1999). To test if the increased resistance of the yggX* mutants to PQ was mediated through the soxRS regulon, various strains with lesions in soxR were constructed and analyzed. Some of the data from these experiments are shown in FIG. 5 . In our system, as in others, a soxR mutant (DM5317) was more sensitive to PQ than the isogenic soxR + strain (DM5319). The growth data showed that a yggX* mutation significantly increased the resistance of the soxR strain to PQ (0.4 μM), but was unable to restore resistance to the wild-type level. We obseryed that a yggX* mutation restored prototrophic growth to a gshA mutant strain, even in the presence of the soxR mutation (data not shown). Together, these results indicated that the resistance to PQ allowed by increased levels of YggX was not mediated through the soxRS system. Since inactivation of enzymes containing labile [Fe—S] centers contributes to the lethality of PQ, these results were also consistent with a model in which YggX protects [Fe—S] centers from oxidation.
It was formally possible that YggX overexpression increased the cellular level of SOD activity independent of the soxRS system. When SOD activity of the wild-type (DM5104) and yggX* mutant strain (DM5105) were measured to address this possibility, they were found to be 6.78±0.49 and 6.61±0.49 units, respectively.
Increased levels of YqqX result in a decreased frequency of spontaneous mutations. A role for YggX in mutagenesis was explored for two reasons. First, the conserved location of yggX adjacent to mutY raised the possibility that YggX was associated with MutY function. It was intriguing that MutY itself contains an [Fe—S] center, while it functions under conditions of oxidative stress in the repair of oxidatively damaged DNA (Boiteux, S. and Radicella, J. P., supra, 1999; Michaels, M. L., et al., supra, 1990; Michaels, M. L., et al., supra, 1992). In a more general context, our working model suggests that YggX reduces the oxidation of [Fe—S] clusters (see below). Thus, YggX would reduce the loss of Fe(II) ions from clusters. The resulting decrease in free-iron levels would generate fewer hydroxyl radicals and thus reduce DNA damage (Keyer, K. and Imlay, J. A., supra, 1996). As an initial test of this aspect of the model, the frequency of spontaneous mutants acquiring resistance to rifampicin or d-cycloserine was determined in several strains. Representative data for these two assays of mutation frequency are shown in Table 2. As shown by the data in Table 2, in an otherwise wild-type background, the yggX* mutation reduced the number of spontaneous mutations by greater than ten-fold. As predicted by our working model, a gshA mutant displayed an increased mutation frequency. When the yggX* mutation was present in the gshA mutant background, the frequency of Rf colonies was decreased from 176 to a background level of 1-2/10 8 . A similar trend was noted in the frequency of spontaneous mutants resistant to d-cycloserine.
Discussion
This work was initiated to characterize a frequent mutation that suppresses the requirement of a class of thiamine auxotrophs (Gralnick, J., et al., supra, 2000). Molecular analysis found the causative mutation, yggX*, increased the level of the YggX protein. Overexpression of the yggX gene was found to alter several metabolic processes “unrelated” to thiamine synthesis. The phenotypes resulting from YggX overexpression are broad enough to suggest a role for this protein in a central metabolic process. Our working model holds that YggX protects labile [Fe—S] clusters from attack by oxygen species, including superoxide.
FIG. 6 depicts the consequences of superoxide radicals relevant to our model for the function of YggX. Superoxide (and/or other oxygen species) attack the labile [Fe—S] centers in a number of proteins (e.g., aconitase) (Flint, D. H., et al., supra, 1993; Gardner, P. R. and Fridovich, I., supra, 1991; Gardner, P. R. and Fridovich, I., supra, 1991; Gardner, P. R. and Fridovich, I., supra, 1992; Flint, D. H., et al., J. Biol. Chem. 268:14732-42. 1993). This molecular attack results in inactivation of the respective enzymes, and release of both free-iron and hydrogen peroxide that generates DNA damaging hydroxyl radicals via Fenton chemistry (Keyer, K. and Imlay, J. A., supra, 1996; Liochev, S. I . and Fridovich, I., supra, 1994; Srinivasan, C., et al., supra, 2000). It was suggested that in a wild-type cell, glutathione minimizes the effects of oxidation damage by providing reductant to facilitate reconstitution of the [Fe—S] clusters (Gardner, P. R. and Fridovich, I., supra, 1993), completing a cycle of damage and repair to the [Fe—S] clusters that remains in equilibrium under normal growth conditions. When GSH is absent (e.g., a gshA mutant), the effects of these oxygen species are exacerbated and the resulting phenotypes include, reduced activity of enzymes with labile [Fe—S] centers (i.e., ThiH, Acn), increased sensitivity to the superoxide (e.g., growth in PQ), and increased mutation frequency. Increasing the level of YggX reversed each of these phenotypes. One interpretation of these results is that YggX acts prior to the damage and protects labile [Fe—S] clusters from oxidation. In this scenario, blocking the initial attack on the [Fe—S] clusters would abrogate the above phenotypes ( FIG. 6 ). It is formally possible the YggX acts to remove superoxide or to facilitate GSH independent repair of the oxidized clusters. We observed no increased superoxide dismutase activity in yggX* mutant extracts, and elevated levels of YggX increased the resistance of a wild-type strain (i.e., not limited for GSH) to superoxide suggesting that cluster repair is not the affected step.
This work and the model described above are consistent with the suggestion that the requirement of gshA mutants for the thiazole moiety of thiamine was due to the oxygen lability of the ThiH enzyme (Gralnick, J., et al., supra, 2000). The recent identification of ThiH as a member of a SAM radical protein family is consistent with this notion since members of this family share a motif that is indicative of an oxygen labile [Fe—S] cluster (Sofia, H. J., et al., Nucleic Acids Res. 29:1097-106, 2001; Frey, P. A. and Booker, S., Advances in Free Radical Chem. 2:1-43, 1999). Thus, the characterization of YggX presented here supports our hypothesis that the role of GSH in thiamine synthesis is in repair of the oxidized [Fe—S] cluster in ThiH (Gralnick, J., et al., supra, 2000).
This work raises a number of provocative questions for future studies. The phenotypes characterized here were the result of relatively high levels of YggX. The conserved location of yggx adjacent to mutY is intriguing. MutY contains an [Fe—S] center and must function under conditions of oxidative stress to perform its role in repairing oxidatively damaged DNA. Considering results herein, we suggest that YggX protects the [Fe—S] cluster of MutY under conditions of oxidative stress. Although in vitro studies on the homolgous enzyme Endonuclease III suggest the [Fe—S] cluster in MutY is not accessible to oxidation (Cunningham, R. P., et al., Biochemistry 28:4450-5, 1989), the need for protection in vivo or perhaps during protein folding following synthesis, maturation, and/or conformation changes associated with function are not ruled out.
The model proposed for the function of YggX in vivo encourages us to develop an in vitro assay for protection of oxygen labile [Fe—S] clusters. Such in vitro experiments may distinguish between various mechanisms that could explain the in vivo results and also help frame questions to dissect the possible connection between MutY and YggX functions.
In summary, our work has provided insight on the function of a previously uncharacterized ORF in S.enterica . By the serendipitous use of a strain that was sensitive to the lack of GSH we were able to identify a phenotype associated with increased cellular levels of YggX and offer a plausible model for the role of YggX in cellular metabolism.
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A method of reducing superoxide damage to a cell is disclosed. In one embodiment, this method comprises the step of engineering the cell to produce more than a native amount of the YggX protein or its homolog, wherein the cells are rendered more resistant to superoxide damage.
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This application is a Continuation of currently pending PCT/IB2010/050784 filed Feb. 23, 2010, which Application claims priority of Spanish Patent Application P200900505 filed Feb. 24, 2009.
FIELD OF THE INVENTION
The present invention relates to a method for reducing interstitial elements in cast alloys. Specifically, it relates to a method for reducing hydrogen in steel castings. The present invention also relates to a system for performing this method, which can be integrated into a mold or a continuous casting system.
BACKGROUND OF THE INVENTION
Throughout this document, the term interstitial elements refers to those atoms that, because of their small size with respect to the main elements in the alloy, are able to diffuse interstitially, that is, via the spaces in the metallic crystalline lattice, without the need to displace other atoms from their positions in the lattice. In the case of many alloys, like steel, atoms like hydrogen, nitrogen carbon and others can act like interstitial elements.
It is known that hydrogen is an interstitial element that can cause the embrittlement of steel components. Specifically, the sensitivity to hydrogen embrittlement is more evident in high-strength alloys.
Various mechanisms have been described as responsible for said embrittlement. These mechanisms do not begin to materialize as long as the temperature does not drop below a given threshold so that the interstitial elements in question feature a reduced mobility and an insufficient solubility, and tend to combine with other elements to form embrittling compounds.
It is known that hydrogen features a solubility which varies from one metallurgical phase to another and at the same time, solubility increases within each phase as temperature increases. For example, in the case of the solid phases of steel, hydrogen solubility ranges between 8 ppm in high temperature austenite (1400° C.), and less than 1 ppm in room temperature ferrite, and it is approximately 30 ppm in the liquid phase at 1600° C.
It can be considered that the phenomenon of diffusion of interstitial elements is governed mainly by the interstitial atom's thermal agitation within the crystalline lattice, i.e., at higher temperatures, greater thermal agitation and, therefore, greater probability of diffusion. Although the situation usually considered is the diffusional flux occurring from high concentration regions towards regions of lower concentration this is not the only possible scenario. Rigorously, the driving force behind diffusional fluxes is the free energy reduction of the system. To be still more precise, diffusion occurs from areas of high chemical potential to areas of lower chemical potential.
Nevertheless, it can be shown that whenever the atomic mobility is sufficient, and in absence of composition differences or other factors which could cause a more important flux, a high temperature gradient also causes a net flux of interstitial elements towards higher temperature regions. This effect is produced because, on the one hand, as regions at higher temperature are in a state of lower saturation, as they feature greater solubility, and therefore they would have a lower chemical potential than regions at higher saturation in the same temperature conditions. On the other hand, the flux towards high temperature regions is encouraged by the increase in atomic mobility as the temperature increases.
The presence of hydrogen in metallic alloys, especially in steels, is due to several reasons, from the presence of humidity in the raw materials or equipment or the decomposition of compounds present in the later, as well as actions performed during the alloy casting and refining process, for example those where hydrogen is blown through the molten metal with the aim of eliminating other elements, with the final consequence that some fraction of the hydrogen used remains dissolved in the molten metal.
During the casting process, heat extraction from the metal occurs through the walls of the mold and from the free surfaces of the cast metal.
In this manner, the cast metal generally cools from the surface to the core of the casting. That is, the casting's core remains at higher temperature than its surface, producing an increasing temperature gradient from the surface towards the core.
This marked temperature gradient, at temperatures at which interstitial elements such as hydrogen still feature a high mobility, produces a flux of interstitial elements towards the casting core, due to its higher temperature and greater capacity to dissolve said elements with respect to the adjacent regions which are at lower temperatures.
This diffusive flux tends to concentrate the total content of the interstitial element in question in the core region of the casting.
Due to the damaging effect of hydrogen in the mechanical properties of the components produced, traditionally different systems have been used to eliminate it.
These systems can be divided into two families: The use of certain additions during the refining process or the exposure of the molten metal to a reduced pressure.
The first of these methods consists in the addition of refining elements or substances that would combine with hydrogen (or other elements) and form insoluble substances that could be then eliminated during the refining process.
The second system consists in exposing the molten metal to an atmosphere with reduced pressure, as hydrogen solubility in the molten metal is function of pressure as well as of temperature and crystalline structure.
This second system produces a better hydrogen elimination rate, although at the expense of a large increase in the investment for the necessary equipment. For its part, the first system entails a much smaller investment, but it has also a lower hydrogen reduction rate, so that it is much less effective. Furthermore, this first system has the added issue that implies the modification of the alloy composition.
Therefore, the need is clear for a method which reduces interstitial elements, particularly hydrogen, in a casting process, without the modification of the alloy composition (with the exception of interstitial elements themselves) and furthermore, without requiring a large investment such as in the case of vacuum casting and refining.
BRIEF SUMMARY OF THE INVENTION
The previously discussed drawbacks are resolved by the method and the system of the invention, featuring other advantages which will be described below.
According to one aspect, the method for reducing interstitial elements in alloy castings of the present invention comprises the steps of:
injecting said alloy in a system for the formation of a casting or a continuous cast; allowing said alloy to cool; wherein at least a peripheral region of the casting is heated, so that the flux of interstitial elements occurs towards at least one the peripheral region.
Consequence of this feature, a method is achieved where most of the interstitial elements concentrate in one or several regions in the surface region of the casting. Later on, such elements can easily be eliminated from these regions by means of a thermal surface treatment or surface machining of the casting.
Preferably, at least one peripheral region is heated before the alloy cools to a temperature low enough for the formation of embrittling compounds.
According to another aspect of the invention, at least one peripheral region is heated at a temperature between 900° C. and the melting point of the alloy.
Such heating of each peripheral region is preferably maintained until any part of the piece, different than the peripheral regions, is at a temperature of less than 400° C.
According to a further aspect of the invention, the interstitial elements are hydrogen, carbon, nitrogen, boron, argon, or other interstitial elements or other elements which feature high diffusivity in the alloy matrix, and said alloy is a steel alloy, iron, copper, nickel, titanium, cobalt, chrome or others with melting points greater than 800° C., as well as some alloys with lower melting points, such as aluminium alloys.
According to still another aspect of the invention, the system for reducing interstitial elements in cast alloys comprises at least one heating element situated on the periphery of the cast.
According to still a further aspect of the invention, each heating element is an electric resistor or an induction coil, and each heating element is complemented with a temperature sensor.
According to sill another aspect, the complete system of the invention can be applied both to mold casting and continuous casting systems.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary as well as the following detailed description of the invention will be best understood when considered in conjunction with the accompanying drawings, and wherein:
FIGS. 1 and 2 are schematic views of a casting system according to the present invention, representing the flux of interstitial elements and the isothermal curves in the cast alloy; and
FIG. 3 is a schematic view of a continuous casting system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
It should be noted that although the present description corresponds to the case of hydrogen reduction during steel casting, the scope of application of the method of the present invention extends to any alloy casting wherein a reduction in the amount of dissolved hydrogen or of any other interstitial element is desired, such as, for example, carbon, nitrogen, boron and others.
Unlike the method of the previously described techniques, according to the method of the present invention the existence of a increasing temperature gradient is forced and directed towards one or more points on the surface of the piece, so that the flux of interstitial elements occurs towards the surface, instead of towards the core of the casting.
In this way, the interstitial elements will be eliminated from the casting by simple diffusion through the surface of the piece, and any remainder concentrates in a region close to the surface, so that it can easily be eliminated by means of a subsequent thermal surface treatment and/or surface machining of the casting.
In order to obtain a temperature gradient favourable to force the interstitial element flux towards the surface of the casting, it is necessary to maintain at least one region of the surface of the casting at a sufficiently high temperature during the solidification and cooling process, so that it is maintained at a higher temperature than the rest of the casting till the end of the process.
In the event of wanting to eliminate an element such as hydrogen, which tends to combine with other atoms, forming embrittling compounds, it is important to ensure that this method is initiated before the piece cools to temperatures at which said embrittling compound formation reactions occur.
As observed in the figures, the system, in this case a mold, indicated generally by means of the numeric reference 1 , comprises a heating element 2 .
It must be pointed out that even though one heating element 2 has been represented in the figures for the sake of simplicity, it is clear that there can be any suitable number of heating elements, depending on the shape and dimensions of the mold.
The or each heating element 2 , which is integrated into the mold wall 1 and begins to actuate during the pouring of the molten alloy into the mold, can consist of an induction coil, duly protected from the liquid metal, or of an electric resistor, or any suitable heating element.
One requirement of this heating element is that it must be built into the mold, at a distance which is sufficiently close to the inner surface of the mold and which reliably permits the region of the surface of the piece to be kept at a suitable temperature.
Another essential requirement of the heating element is its capacity to endure temperatures higher than that of the alloy's melting point, and especially the thermal shock produced during the filling of the mold.
For example, in the event of treating cast steel pieces, the temperature to be maintained can exceed 1400° C., and the temperature of the molten metal can exceed 1600° C.
In the event that an electric resistor is used as a heating element, this can be built integrated into the wall of the mold, surrounded and protected for example by an alloy resistant to the temperature, or ceramic refractory material, or even integrated into the wall of the mold in the case of sand casting.
Heating elements using an electric resistor are expected to be tougher and less expensive, and might require a simpler control system, than in the case of an induction coil, although they feature a larger heat lag.
If the heating element is realised using an induction coil, the surrounding material must not be conductive in order to prevent the generation of induced currents, since these induced currents would heat the heating element or the walls of the mold, instead of the surface of the casting.
Each heating element 2 is connected to a temperature sensor 3 , a control system 4 and an energy supply system 5 .
The control system 4 is required to adjust the temperature of the heated peripheral region (or hot spot) and could be similar to those normally used for automated surface induction heat treatments.
Additionally, the type and the placement of the temperature sensor 3 must be suitable to prevent the magnetic field generated by the induction coil from distorting the temperature measurement, and this must be situated so that it directly measures the temperature of the surface of the casting.
In this sense, a heating element 2 based on an induction coil it is expected to require a slightly greater investment than that based on a resistor, but has the advantage that it permits a much quicker and precise modulation of the temperature obtained.
An alternative embodiment to mold 1 of FIG. 1 has been represented in FIG. 3 , which depicts the application of he method to a continuous casting system. In this embodiment, the same numeric references have been maintained to identify elements equivalent to those in the previous embodiment.
A continuous casting system 10 , whose main functioning is identical to that of the mold 1 , is represented in FIG. 3 .
In this case, the molten metal is deposited in a distribution tank 11 , wherefrom it forms a cast bar 12 by means of a cooled ingot mold 13 .
At the outlet of the ingot mold 13 , the cast bar 12 is cooled on one side by means of a cooling section 14 , while the heating elements 2 are situated in contact with one of the surfaces of the cast bar 12 . Its ideal arrangement is next to the outlet of the ingot mold 13 and along the section of the refrigeration 14 on its opposite side.
The cast bar 12 can be cooled with water jets or spray, as it is conventional practice, although protecting from said cooling process the side where the heat is applied for the elimination of the interstitial elements (the heated peripheral region or hot spot).
Table 1 contains some examples of the range of temperatures implied in the method of the present invention, for different alloys.
It must be pointed out that the temperature whereat the peripheral regions of the mold have to be maintained have to be as high as possible from a practical point of view, but comfortably less than the melting point of the alloy.
TABLE 1
Illustrative values, for different alloys, of the melting
temperature, the temperature at which hot spots on
the surface of the casting should be kept at and the
critical core temperature.
Hot spot
Critical
Alloy
Melting point
temperature
temperature
Low C steel
1750° C.
1000° C.-1700° C.
400° C.
High C steel
1580° C.
1000° C.-1500° C.
400° C.
Alloy steel
1700° C.
1000° C.-1600° C.
400° C.
Cast iron
1400° C.
1000° C.-1350° C.
400° C.
Copper
1350° C.
900° C.-1300° C.
400° C.
Nickel alloys
1550° C.-1700° C.
1000° C.-1600° C.
400° C.
Regarding the holding time necessary at each heated peripheral region or hot spot, this time at temperature depends on the volume and the geometry of the casting in question. Nevertheless, it must be stressed the importance that the heating elements produce the hot spots on the surface of the casting must be active from the moment when the mold is filled. These hot spots must also be held at the suitable temperature until the temperature of the core of the casting has decreased below a critical temperature (approximately 400° C.).
Once the core reaches such said critical temperature, the power applied to the heating element can be slowly reduced, always guaranteeing that the hot spot is at a higher temperature than the core regions of the casting, until both are below the critical temperature. The time necessary to cool the core below the critical temperature can be estimated from some simple modelling of mold and casting cooling.
Despite having referred to a specific embodiment of the invention, it is clear for a person skilled in the art that the method and the mold disclosed can undergo numerous variations and modifications, and that all of the mentioned details can be substituted for other technically equivalent details, without departure from the scope of protection defined by the attached claims.
For example, possible modifications can be as follows:
instead of using a temperature measurement system, the control system can be managed by other means (for example, simply by determining, via modelling or experimentally the holding time necessary for each hot spot(s) to produce the right effect and setting their heating time accordingly); the heat applied to the surface of the casting do not need to be continuous, but followed a suitable function, with varying intensity; the surface heating of the surface of the casting is maintained until the core temperature drops below 400° C.; the interstitial elements do not need only to be diffused to the region below the surface where the heating is being applied, but due to the proximity of such surface, a fraction of such interstitial elements could diffuse out of the metal (desorption) and, therefore, obtaining their elimination from the casting; and the heating elements could be implemented either integrated in the mold walls, or as removable attachments associated therewith.
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The method for reducing interstitial elements in alloy castings which comprises the following steps: pouring the alloy for the formation of a casting; and allowing said alloy to cool. According to the method, at least a peripheral region of the casting is heated, so that the flux of interstitial elements is caused towards the at least one peripheral region. The method is achieved where most of the interstitial elements concentrate in at least one region in the surface region of the casting. At later stages these elements can be easily eliminated from the respective regions by means of a thermal surface treatment or surface machining of the casting.
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This is a division of Ser. No. 08/934,265, filed Sep. 19, 1997, and a formal application replacing provisional application Ser. No. 60/026,829, filed Sep. 27, 1996.
This invention relates to means for and methods of preparing a glue or adhesive, on a batch basis, for making corrugated board and especially for introducing more lye during a preparation of a glue used in a corrugation machine.
BACKGROUND OF THE INVENTION
There are special characteristics for glue which is used in a system for making corrugated cardboard. Among other things, these characteristics include a gelatinization of starch in order to obtaining a desired gel point at a faster rate. The starch gelatinizes in response to a certain quantity of NaOH (Lye) which is introduced into a compound that includes at least water and starch. With the development of machines that produce corrugated board at speeds that are much higher than previous speeds, much higher demands are being placed on the glue or adhesive that is used and the speed at which such glue or adhesive is produced.
Currently, most starch-based glues or adhesives and their production are based on the "Stein-Hall" patent (U.S. Pat. No. 2,102,937). These adhesives are based on:
a gelatinized starch carrier which is used at a viscosity that keeps the secondary starch in suspension and which determines the rheology, the structure, and the visco-stability of the glue. These characteristics greatly influence the amount of glue that is applied on the glue rolls and thus on the paper in the corrugator.
uncooked starch (raw starch) that gelatinized in situ at the corrugator machine results in a rapid gelatinization and formation of a "wet tack, green bond" between the corrugated medium and the liner.
alkaline reagents, commonly caustic soda, assist in the gelatinization of the carrier starch and a lowering of the gelatinization temperature of the uncooked starch. This speeds up the gelatinization "in situ" of the raw starch.
"borax", increases the viscosity (wet tack, green bond) when the uncooked starch is gelatinized on the corrugator.
An example of currently used formulations contain 80-77% water, 2-3% gelatinized starch, 25-18% raw starch, 0.1-0.5% caustic soda, and 0.05-0.5% borax.
The gelatinized starch can be unmodified maize (corn), wheat, tapioca or potato starch. Or it is a modified crosslinked starch which enhances the rheological characteristics of the glue that improve its runnability on the machine.
The raw starch can be native or modified crosslinked maize, wheat, potato, or tapioca. The best suited starch has a natural low gelatinization temperature and a high viscosity when gelatinized "in situ" on the corrugator. When this happens, a minimal amount of chemicals (caustic soda and borax) is needed, especially borax, since boron is toxic.
To increase the production speed of the corrugated board machine, a faster adhesive formulation can be prepared. The "Stein-Hall" adhesive can be modified in two ways:
the amount of caustic soda is increased in order to decrease the gelatinization temperature of the uncooked starch. This results in a faster gelatinization and the formation of a bond between the medium and the liner.
the amount of uncooked starch is increased in order to decrease the amount of water that has to be evaporated from the board. The board is then dry with less time and energy.
Currently, most "Stein-Hall" adhesives are prepared in a one tank system in the corrugated board factory.
A sequence for making such an adhesive is:
make a slurry of the carrier starch which is 10 to 17% dry solid
heat to 30-55° C.
and add caustic soda
stir until the viscosity is stable
dilute with water
add raw starch
add borax
stir until the viscosity is stable
Now formulas are used with a higher amount of caustic soda (lye) and higher amount of raw starch in order to increase the dry solids and to increase the binding speed of the adhesive. The concentration of the caustic soda in the slurry is so high that, when the secondary starch is added into the slurry, the first part of the raw starch partial gelatinizes. This also happens when a gelatinized carrier starch is added to a slurry of raw starch, which this causes an increase in viscosity and deteriorates the viscosity stability of the glue. It also limits the maximum concentration of dry solids in the glue. More important, a premature gelatinization tends to limit the amount of lye that can be added.
A method for the batch preparation of a glue for corrugated board is known from European patent application No. 0 391 477 which provides an excellent result. However, since lye is added at one time, the rapid gelatinization limits the amount of lye that can be introduced into the carrier.
According to Example 1 of this European patent application, the carrier is prepared by adding water, starch, and a NaOH-solution to a first, relatively large, mixing vessel. The contents of the first, relatively large mixing vessel, are circulated from and to the first mixing vessel via a recirculation pipe, in which a second and comparatively smaller mixing vessel is incorporated. The smaller vessel is also provided with means for exerting a shearing force upon the mixture. The shearing forces are much greater in the smaller vessel than in the large mixing vessels. In the second step, water, starch, and powdered borax are supplied to the carrier, which has been prepared in the first mixing vessel, with continuous stirring and recirculating.
Further research has shown that it is possible to improve the properties of the glue which is thus prepared. In particular, is possible to prepare a homogeneous glue. An inhomogeneity may be eliminated by a prolonged circulation of the mixture via the recirculation pipe and the relatively small mixing vessel which is present therein.
SUMMARY OF THE INVENTION
The invention is particularly focused on preventing the swelling of the raw starch in the glue or adhesive by dosing liquid caustic soda (lye) in a controlled manner. Caustic soda is a catalyst for causing a chemical reaction in starch slurries. The raw starch should only swell "in situ" on the corrugator.
Accordingly, an object of the invention is to provide a method of preparing a glue which enables a relatively short mixing time. As a result, the production capacity is increased in comparison with the production capacity of the prior art method using approximately the same amount of equipment. It is also possible to process starches having a high peak viscosity.
According to an aspect of the invention, part of the caustic soda (lye) is added after the addition of raw starch to the preparation. When adding liquid caustic soda into a starch slurry in a continuously or semi-continuously controlled manner within a mixing zone, it is possible to prevent the swelling of the raw starch. Also, liquid caustic soda is slowly added to a slurry to prevent a partially solubilizing of the starch. The purpose of this use of caustic soda is to prevent a loss of efficiency and to have a constant reaction in each starch granule. This makes it possible to have higher dry solids and a viscosity stable adhesive with a lower gel temp.
Heretofore, the industry has not prevented the solubilizing of the starch in order to prevent viscosity increases. The purpose of this invention is to increase the efficiency of the chemical reaction with the starch granule.
In keeping with a further aspect of the invention, a system for preparing a glue that is used to make corrugated cardboard has a first and relatively large mixing vessel containing a stirrer. A second and smaller mixing vessel is connected thereto via a recirculation pipe. The second mixing vessel includes a stirring means for exerting a shearing force which is greater than the shearing force exerted in the first mixing vessel. The preparation is carried out in two steps. A first step is to prepare a carrier starting from water, starch, and lye. Then, a second step adds the remaining amount of starch, water, lye by injecting it into second mixing vessel, and then borax is added to the carrier. The aggregate is mixed into a homogeneous mixture. The amount of starch used in the first step is smaller than the amount of starch used in the second step.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be better understood by studying the following description taken with the attached drawings, in which:
FIG. 1 schematically shows a preferred system for making glue or adhesive for a corrugator;
FIG. 2 graphically shows how potato, corn, and wheat starch changes with temperature and time;
FIGS. 3 and 4 graphically show how the potato, wheat, and corn starch gel point changes with the amount of caustic soda (lye) that is applied in one shot and the percentage of lye to starch that is used and;
FIGS. 5 and 6 are similar to FIG. 3 and graphical show how the gel point changes with the amount of caustic soda (lye) that is applied in two shots.
SYSTEM APPARATUS
In greater detail, a system (FIG. 1) for carrying out a batch preparation of glue for corrugated board comprises a first and large mixing vessel 1, containing a stirrer 3, and comprising pipes 15, 10 for supplying starting materials, such as starch and water, respectively. A discharge pipe 12 discharges a glue product from vessel 1. The first mixing vessel 1 is coupled to a recirculation pipe 20, in which a second and comparatively smaller mixing vessel 2 is incorporated. The second and smaller mixing vessel 2 contains a stirring means 4 for exerting a shearing force which is greater than the shearing force exerted in the first mixing vessel 1. Preferably, means 4 comprises at least two chambers, each of which contains a mixing disc. These two mixing vessels 1 and 2, together with discharge pipe 12 and recirculation pipe 20, make up the recirculation system or the reactor in which the preparation of the glue takes place.
According to the invention, the second mixing vessel 2 is provided with a pipe 16 for supplying caustic soda (lye). The advantage of supplying of lye to the second mixing vessel 2 is that the means 4 exerts a shearing force which is higher than the shearing force exerted in the first mixing vessel 1; therefore, the lye comes into contact with the starting materials at a location where a vigorous mixing takes place (in the second mixing vessel), which prevents inhomogeneity.
Preferably, the second mixing vessel is connected to a source of borax via a supply pipe 17. It is preferable to supply borax to the second mixing vessel 2, in which vigorous mixing takes place, in order to prevent large viscosity fluctuations caused by poor mixing.
In operation, container 5 supplies starch to the first or large mixing vessel 1 via pipe 15. Water is supplied to mixing vessel 1 via pipe 10. Lye, in particular caustic soda, is supplied from container 6 to mixing vessel 2 via pipe 16.
The carrier is formed by starch, water and lye. Borax is supplied from supply 7 to the second or smaller mixing vessel 2, via pipe 17. If desired, the borax may also be supplied to mixing vessel 1 as well as to mixing vessel 2. The preferred form of the borax is a solution or a suspension.
Mixing vessel 1 may be heated by supplying steam thereto via pipe 11. During the preparation of the glue, the temperature is maintained at 20-40° C. The pump 13 sends the reaction mixture from mixing vessel 1 to mixing vessel 2 via recirculation pipe 12 and valve 14. The greater shearing forces exerted in vessel 2 obtain the desired viscosity more quickly. Container 8 holds a different type of starch for the secondary carrier supplied through pipe 18 into vessel 1.
As soon as the desired final product homogeneity of the glue is reached, valve 14 may be adjusted so that the desired final end product is discharged to a distribution system via pipe 9. This system may include any well known corrugator for making corrugated board.
According to the present invention, it is possible to use starches which have a high peak viscosity, such as potato starch. The amount of lye which is metered in two steps is larger than the amount of lye which is metered in a single step. Furthermore, a lower gelling point is obtained with lye being metered in with two steps, in comparison with the gel point when the lye is metered in a single step, as is usual in the prior art.
In the inventive device, it is possible to prepare the carrier from starch, water and lye after stirring for about 5 minutes. The remaining components of the glue are supplied to the carrier in order to produce a final composition, having the desired homogeneity and viscosity, within 15 minutes.
DETAILED DESCRIPTION OF THE INVENTION
In the first step, water and starch are supplied to form a carrier in the first mixing vessel and then the resulting carrier is transported to the second mixing vessel. Lye is first added in a controlled manner in the second mixing vessel to prepare the carrier. The carrier reaches a stable viscosity after a recirculation from the first to second mixing vessels has taken place. After the remaining amounts of starch and water have been added to the carrier, lye is supplied in an even manner to the second mixing vessel and thereafter that borax is added. During a period involving a means for exerting great shearing forces upon the concentration, a homogeneous composition is obtained directly in the second mixing vessel. As a result, the mixing time is reduced.
The term "stable viscosity" is used herein to mean a viscosity value that will remain stable even if the carrier is thereafter stirred or recirculated over a prolonged period of time.
According to another preferred embodiment of the invention, after supplying the remaining amounts of starch and water to the prepared carrier, an additional amount of lye is supplied to the second mixing vessel before borax is added thereto. By metering lye in two stages, it becomes possible to supply an amount of lye in the first step which is smaller than the total amount of lye that is required. The secondary starch (that is, the starch to be added in the second step) is not affected by any excess amount of lye that may be present in the carrier. Hence, there is little or no limitation imposed by a premature gelatinization.
After the water and starch have been mixed in the first step, an amount of lye sufficient to cause the desired swelling or gelling of the starch is added to the mixture of water and starch via the second mixing vessel. Then, a vigorous mixing takes place in the second mixing vessel, after which water and starch are supplied via the first mixing vessel to the mildly alkaline carrier that is being prepared. Because the carrier prepared in the first step contains only a limited amount of lye that is adapted to the amount of starch that is present at that moment, the starch supplied thereto in the second step is not affected. After the starch and water have been added in the second step, the additional amount of lye is added to the carrier, followed by a metering of borax into the mix.
The amount of lye supplied to the carrier prepared in this manner leads to a lowered gelling point. In practice, it has been found that the gelling point of maize starch is lowered by about 5° C. per gram of NaOH (lye) added to one liter of a carrier (whereby this NaOH (lye) is converted into 100% solid matter). The 5° C. per gram may vary somewhat depending upon the alkaline sensitivity. Thus, in accordance with the inventive method, it is possible to lower the gelling point by about 40° C. That is, a dose of 8 g/liter of lye is used. The maximum lowering of the gelling point that can be achieved with the prior art method is about 36° C.
Research has shown that the lowering of the gelling point depends on the type of starch that is used. Thus, for example, a lowering of about 2.5° C. per gram of NaOH (lye) added to one liter of carrier is achieved with potato starch. In practice, it is desirable for the gelling point to be lowered because then a higher processing speed of the glue is possible.
More particularly, the total amount of lye supplied in the first and the second step is greater than the total amount of lye supplied in a single step. By supplying lye in two stages, the amount of lye supplied in the first stage is sufficient to control a swelling of the starch present in the carrier that is being prepared. A carrier which is mildly alkaline is obtained. As a result, the amount of starch to be supplied in the second step is not affected, after which the remaining amount of lye for lowering the gelling point is supplied, preferably in the second mixing vessel, to the slurry which has been thus prepared. In other words, the amount of lye supplied in the first step for preparing the carrier according to the present invention is less than the amount of lye supplied in the second step according to the prior art. Because the secondary starch is not affected, it is possible to use a larger amount of lye than is used in the when lye is supplied in a single step.
The invention will be further understood by a study of the following examples.
EXAMPLE 1
In this example, a glue making system shown in FIG. 1 has a capacity of 2000 liters (net capacity: 1900 liters). A cross-linked potato starch, a solution of caustic soda, and a solution of borax were used.
To prepare the carrier, 200 liters of water were supplied to the first and larger mixing vessel 1 and heated to 40° C. Next, 40 kg of potato starch were added. The water and starch were mixed and circulated for about 30 seconds, during which the stirrer in mixing vessel 2 was set to 1500 revolutions, per minute. Then, 20 kg of a 33% lye solution were supplied to the second and smaller mixing vessel 2 during a period of 3 minutes.
After stirring and circulating for 7 minutes, 1184 liters of water were supplied to the first mixing vessel. A total of 17.8 kg of borax solution (Eurobox 3X borax 10 AQ, 1.5%) was supplied simultaneously to the smaller mixing vessel 2. Finally, the remaining amount of starch (405 kg of potato starch) was supplied to the larger mixing vessel 1 during a period of 2 minutes.
The resulting composition was subsequently mixed for 1 minute, after which 2027 kg of glue was obtained in 22 minute. The contents of mixing vessel 1 were discharged to distribution system 9 for 5 minutes.
EXAMPLE 2
A carrier was prepared according to the method of Example 1, with a difference that a natural starch was used. Because natural starch was used, the amount of lye used during the preparation of the carrier was less than the amount that was used in Example 1. The carrier which was thus prepared included 400 liters of water, 80 kg of natural starch, and 20 kg of a 33% lye solution (supplied to mixing vessel 2). After supplying 1184 kg of water and 17.8 kg of borax solution in the second step, 365 kg of natural starch were added. From this, it appears that the capacity of the inventive device was larger when natural starch was used than when a modified starch was used. The modified starch was cross-linked potato starch, as described in Example 1.
EXAMPLE 3
The carrier of Example 1 was produced, except that 12 kg of a 33% lye solution (supplied via the smaller mixing vessel 2) was used for preparing the carrier during the first step. Then, after adding the remaining amounts of water and starch to mixing vessel 1, a second amount of 10 kg of a 33% lye solution was supplied to the second mixing vessel before supplying borax thereto. The glue which was thus prepared had a gelling point of 46 ° C. This gelling point is lower than the gelling point of the glue prepared in Example 1, which had a gelling point of 50° C. The amount of lye supplied in Example 3 was 22 kg of a 33% lye solution, while the amount of lye supplied in Example 1 was 20 kg of a 33% lye solution. The lowering of the gelling point was ascribed to the increased amount of lye that was added in two steps. On the other hand, the amount of lye in Example 1 was added in a single step.
COMPARATIVE EXAMPLE
In this comparative example, the starch was a modified maize starch (mylbond BKF) used with a solution of caustic soda and borax as the solid substance. This comparative example corresponds to Example 1 of European Patent Application 0 391 477.
In order to prepare the carrier, 430 liters of water, 43 kg of starch, and 11 liters of a 30% NaOH-solution were supplied to the larger mixing vessel 1. The stirrer 3 in mixing vessel 1 was set to 1500 revolutions per minute. The temperature in the mixing vessel 2 was maintained at about 20° C. The stirrer 4 was set to 1500 revolutions per minute while pump 13 circulated the contents of mixing vessel 1.
For the second step, 680 liters of water, 257 kg of starch, and 2.5 kg of borax were supplied to form the carrier, which was prepared in the first mixing vessel. The stirring and recirculating were continued. The carrier under preparation had to be stirred for at least 15 minutes in order to obtain a homogeneous mixture. In addition, it was only possible to prepare a homogeneous carrier by vigorously stirring in mixing vessel 2. The viscosity of the carrier appeared to change, even after 10 minutes.
It should be apparent that, when all starting materials are added to the first mixing vessel in order to prepare the glue, a longer mixing time is required to obtain a homogenous solution as compared to the mixing time with the inventive embodiment where lye was added to the second mixing vessel, as described in Example 1. In addition, it has become apparent that the adhesive power of the glue prepared in accordance with the comparative example is lower than the adhesive power of the glue prepared in accordance with Examples 1-3.
COMPARISON OF ONE-SHOT/TWO-SHOT SYSTEM
During preparation, dosing the NaOH (lye) into the glue in two portions can obtain a lower gel point as compared to the conventional way by dosing all of the required NaOH at one time, especially for glue used in the double-backer corrugating machine. With two doses the native powder in the glue does not swell. A minimal quantity of a NaOH is necessary to enable a complete gelatinization of the carrier starch. The rest of the NaOH takes care of the desired gel point and can be dosed as a last component to be added to the glue.
Another important fact is the concentration and the temperature of the glue. When the concentration and temperature are higher, the secondary starch swell faster.
During research, the maximum quantity of NaOH (lye) that can be dosed under certain conditions was studied and the differences between potato starch, wheat starch, and corn starch during this process were noted. At least, theoretically, the lowest gel point with the lowest NaOH quantity can only be achieved with potato starch. Also, theoretically, it is to be expected that with a concentration of 0.6% NaOH on water, the starch will start swelling. A concentration of 1% NaOH on starch will lower the gel point with about 6.5° C.
For the investigation, a 25% alkaline slurry (on dry material) of native corn, wheat, and potato starch was chosen. No complete glue was made with just a carrier and borax. The reaction temperature was 30° and 40° C. The research also included "one shot" tests carried out in the manner of the prior art and "two-shot" tests carried out in the manner of the invention.
One-shot NaOH: all NaOH is placed in the water, and then used for dosing the starch.
Two-shot NaOH: first a part of the NaOH is placed in the water, then in starch, and last the rest of the NaOH is added.
Raw Materials Used:
Potato Starch: Food quality, 18.7% moisture
Corn starch: Amylum, 11% moisture
Wheat starch: latenstein, 11% moisture
NaOH: 33% concentration
The starches were used and tested for alkaline-sensitivity; no granule damage perceptible.
______________________________________Apparatus Used:______________________________________Waterbath IKA 30° c.q. 40°Mixer IKA 500 rpm + 3 wing propellerStarch dosing screw Retsch Capacity 150 kg/min.Viscosity meter Brookfield RVT 20 and 100 rpmGelcup Elgebee Plate 200° C. and magnet mixer 800-1000 rpmpH meter Radiometer measurement at 30° c.q. 40° C.______________________________________
The results of this research is set forth below:
______________________________________A. Potato Starch______________________________________ONE-SHOT(Prior Art)NaOH on starch 1.0% 1.2% 1.5% 1.8%NaOH on water 0.33% 0.4% 0.5% 0.6%Analyses at 30° C.pH 12.15 12.3 12.5Brookf.20/100 0/20 20/60 1160/1120Gelpoint 52° 49.5° 47°Analyses at 40° C.pH 11.9 12.1 12.3Brookf.20/100 0/28 125/170 3000/2800Gelpoint 54° 52° 49.5°TWO-SHOT(Invention)First shot 1.0% 1.0% 1.0% 1.0% 1.0%Second shot 0.2% 0.5% 0.8% 1.1% 1.4%NaOH on starch 1.2% 1.5% 1.8% 2.1% 2.4%NaOH on water 0.4% 0.5% 0.6% 0.7% 0.8%Analyses at 30° C.pH 12.35 12.4 12.5 12.7Brookf.20/100 0/20 0/27 5/40 80/110Gelpoint 49.5° 47° 44.5° 42°Analyses at 40° C.pH 12.15 12.25 12.35Brookf.20/100 0/30 240/220 950/730Gelpoint 52° 49.5° 47°______________________________________B. WHEAT STARCH______________________________________ONE-SHOT(Prior Art)NaOH on starch 1.0% 1.2% 1.5% 1.8%NaOH on water 0.33% 0.4% 0.5% 0.6%Analyses at 30° C.pH 12.15 12.25 12.4Brookf.20/100 0/30 30/60 20000/8000Gelpoint 55.5° 53° 50.5°Analyses at 40° C.pH 11.9 12.1 12.35Brookf.20/100 0/25 15/40 28000/10000Gelpoint 58° 55.5° 53°TWO-SHOT(Invention)First shot 1.0% 1.0% 1.0% 1.0%Second shot 0.2% 0.5% 0.8% 1.1%NaOH on starch 1.2% 1.5% 1.8% 2.1%NaOH on water 0.4% 0.5% 0.6% 0.7%Analyses at 30° C.pH 12.1 12.3 12.45 12.7Brookf.20/100 0/20 7/35 35/60 100/140Gelpoint 55.5° 53° 50.5° 48°Analyses at 40° C.pH 12.1 12.25 12.4Brookf.20/100 11/40 100/140 800/600Gelpoint 55° 53° 50.5°______________________________________C. MAIZE (CORN) STARCH______________________________________ONE-SHOT(Prior Art)NaOH on starch 1.2% 1.8% 2.4% 3.0%NaOH on water 0.4% 0.6% 0.8% 1.0%Analyses at 30° C.pH 12.3 12.45 12.75 12.95Brookf.20/100 0/20 0/20 25/75 2400/2400Gelpoint 63° 60° 56.5° 53°Analyses at 40° C.pH 12.3 12.5 12.7Brookf.20/100 0/20 0/20 660/800Gelpoint 63° 60° 56.5°TWO-SHOT(Invention)First shot 1.8% 1.8% 1.8%Second shot 0.6% 1.2% 1.5%NaOH on starch 2.4% 3.0% 3.3%NaOH on water 0.8% 1.0% 1.1%Analyses at 30° C.pH 12.75 12.95 13.0Brookf.20/100 0/30 0/40 30/72Gelpoint 56.5° 53° 50°Analyses at 40° C.pH 12.7 12.9Brookf.20/100 18/62 2800/4200Gelpoint 56.5° 53°______________________________________
OBSERVATIONS
The gel point measurements were hampered because of the extremely high concentration and the absence of carrier and borax. This is why the swelling is very abrupt. Further, it was more difficult to have the second shot NaOH (lye) well spread than it would have been if it was done with a commercial mixing device, as distinguished from a laboratory appliance. This was especially true with the wheat starch test.
The Brookfield viscosity gives a clear image of the degree and speed of the swelling. With the two-shot system, the swelling is much slower than with the normal one-shot system, where wheat shows the fastest progression.
______________________________________Achievable minimum gel points in 25% concentrations: Potato Wheat Corn______________________________________One-shot 30° C. 50° C. 53° C. 55° C.Two-Shot 30° C. 45° C. 50° C. 53° C.One-shot 40° C. 54° C. 55° C. 59° C.Two-shot 40° C. 51° C. 53° C. 56° C.______________________________________
The data of the measurement test results are shown in Table A.
TABLE A______________________________________ 1 2 3______________________________________Product name Potato starch Corn starch Wheat starchpH Value before measurement 7.40 5.68 6.35pH value after measurement 6 6.45 6.7Starting viscosity 21 20 24Gel temperature 64.8 84.7 71.4Peak viscosity 1374 360 35peak temperature 88.5 89.5 71.4Viscosity 90° C. 1348 172 396Viscosity 90° C., 20 min. 931 362 600Viscosity 75° C. 962 331 588Viscosity 60° C. 1074 345 700Viscosity 45° C. 1264 394 945Viscosity 30° C. 1489 461 1409Viscosity 20° C. 1511 477 1594Viscosity 20° C., 20 min. 1385 503 2543Measure head 250 250 250Concentration 2 5 8______________________________________
The advantages of the invention should now be clear. Caustic soda (lye) is added in two parts so that the total amount of caustic soda (lye) can be higher than it would be when it is dosed in only the carrier. The way of doing this is by injecting the caustic directly into the second mixing vessel. Otherwise, the starch will gel in an uncontrolled manner if too much lye is added in the first mixing vessel.
If the total amount of caustic soda (lye) is dosed in only the carrier, the concentration of the caustic soda in the resulting slurry is still to high even after the secondary water has been dosed. What happens then is that part of the secondary starch will swell as soon as it enters the slurry.
With the inventive two shot method, only a small amount of caustic is dosed in order to swell the carrier starch. After the carrier is mixed and the viscosity is brought down to a stable value, secondary water and starch is added. The slurry now has a much bigger quantity of caustic so that the additional amount of caustic can be higher. However, this bigger quantity of caustic must be added in the second mixing vessel in a controlled manner.
By having more caustic in the glue, the gel temperature is lower which give the opportunity to produce corrugated board at a higher speed because less heat is needed.
Those who are skilled in the art will readily perceive how to modify the invention. Therefore, the appended claims are to be construed to cover all equivalent structures which fall within the true scope and spirit of the invention.
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The invention provides a process for the preparation of a starch based glue for making corrugated board. The process is carried out in a system which includes a first and relatively large mixing vessel containing a stirrer. A second and smaller mixing vessel is connected to the first vessel via a recirculation path. The second and smaller mixing vessel contains means for exerting a shearing force which is greater than the shearing force exerted in the first and larger mixing vessel. The process is carried out in two steps. A first step is to make a carrier by combining water, starch and a limited amount of lye in the large vessel. A second step adds further amounts of starch, water, borax, and a second shot of lye to the carrier while in the small vessel. Adding lye in two steps is a principal aspect of the invention. If all lye is added in one step, it must be limited to an amount which does not prematurely gelatinize the starch to a level which defeats the glue making.
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CROSS REFERENCE TO RELATED APPLICATION(S)
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
TECHNICAL FIELD
[0004] The present invention is directed toward geocomposites for use in geotechnical construction sites, and particularly toward geonets usable with geotextiles in forming such geocomposites.
BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEMS POSED BY THE PRIOR ART
[0005] Geotechnical engineering and the usage of geosynthetic materials are very common in today's civil engineering marketplace. One of the most common geosynthetic material available today are drainage products. Drainage products are generally comprised of a geonet or material or a geonet combined with a filtration fabric which may be one of many varieties. These products are used for a broad variety of applications. Common applications include drainage/leachate collection layers in waste storage facilities, leak detection layers in waste storage facilities, the use of a geosynthetic drainage material for gas venting in water and wastewater storage and treatment facilities, the use of geosynthetic drainage layers in roadway, rail and transportation applications and many others. In all of these applications, there are generally two performance factors which determine the suitability of the drainage media. These performance factors are the transmissivity (flow capacity) of the drainage media and the maximum allowable overburden pressure which the drainage media can support and still perform the functions required of it.
[0006] Waste collection sites are, of course, one well known type of geotechnical construction site, and are unavoidably required in today's societal structures. Such sites can require large amounts of valuable land, particularly in urban areas where large amounts of waste are generated and, at the same time, land is most in demand. Also, while desirable uses can be made of such lands (for example, golf courses have been built on such sites), such desirable uses typically have to wait until the land is no longer being used for collect further waste and the often high pile of waste has stabilized. While use and stabilization of such sites can take many years, there is nevertheless a desire to have that accomplished as quickly as possible, not only to increase the safety of those who might have to be at the site but also to allow for the desired use of others (for example, golfers) and to enhance the environment of those who live in the area as soon as is reasonably possible.
[0007] Toward that end, bioreactor landfills have been used to modify solid waste landfills by re-circulating and injecting leachate/liquid and air to enhance the consolidation of waste and reduce the time required for landfill stabilization. To accomplish this, generally horizontal flow of the leachate/liquid beneath the surface of the landfill is required. In some instances, vertical injection pipes and horizontal pipe fields have often been used to facilitate this leachate/liquid flow. With these structures, geocomposites are commonly provided in spaced layers of the built up land masses. Other masses may use such geocomposites where drainage (e.g., along a highway edge), leachate collection (e.g., at the bottom of a landfill), or gas removal (e.g., under a building slab) are required. Such geocomposites facilitate desired lateral drainage, collection and/or circulation of fluids (including liquids and/or gases) in the land mass. U.S. Pat. No. 6,802,672 discloses one advantageous system directed toward such problems.
[0008] It is desirable to provide geotextiles which will allow for large fluid flow rates along the geotextile. However, given the large loads which such geotextiles are subjected to as more and more layers of land mass are piled on top of the layers, compression and/or collapse of the geotextile and result, thereby reducing the flow rate through the geotextile. Further, while additional components, etc. may be added to strengthen the geotextile against collapse, those additional components may themselves block and thereby reduce the flow rate as well.
[0009] The present invention is directed toward overcoming one or more of the problems set forth above.
SUMMARY OF THE INVENTION
[0010] In one aspect of the present invention, a geonet for use in a geotechnical construction site is provided with a length substantially greater than its width. The geonet includes no more than first and second layers of strands, where a first plurality of substantially parallel strands extends in the lengthwise direction and defines the first layer of strands, and a second plurality of substantially parallel strands is disposed on top of the first plurality of strands and defines the second layer of strands, the second plurality of strands being at an angle relative to the first plurality of strands. The first and second plurality of strands are substantially incompressible and secured to one another at crossover locations.
[0011] In one form of this aspect of the present invention, at least one of the first and second plurality of strands is substantially round in cross-section.
[0012] In another form of this aspect of the present invention, the geonet is stored in a roll having X number of layers with each strand of the first layer of strands being rolled X times.
[0013] In still another form of this aspect of the present invention, the first layer of strands is the bottom layer of strands when installed, and strands of the first plurality of strands are substantially round in cross-section.
[0014] In yet another form of this aspect of the present invention, the strands of the second plurality of substantially parallel strands are at an angle of 45° to 70° relative to the first plurality of strands.
[0015] According to another form of this aspect of the present invention, the strands are polyethylene (PE).
[0016] In another aspect of the present invention, a geocomposite for use in a geotechnical construction site is provided, including a geonet having a length substantially greater than its width, and with no more than first and second layers of strands. A first plurality of substantially parallel strands extends in the lengthwise direction and defines the first layer of strands, and a second plurality of substantially parallel strands disposed on top of the first plurality of strands defines the second layer of strands. The second plurality of strands is at an angle relative to the first plurality of strands, and the first and second plurality of strands are substantially incompressible and secured to one another at crossover locations. A geotextile is bonded to at least one side of the geonet.
[0017] In one form of this aspect of the present invention, at least one of the first and second plurality of strands is substantially round in cross-section.
[0018] In another form of this aspect of the present invention, both of the first and second plurality of strands are substantially round in cross-section.
[0019] In yet another form of this aspect of the present invention, the geotextile is non-woven textile laminated to the outer faces of the layers of strands. In a further form, the strands are polyethylene (PE) and, in another form, the geotextile is non-woven needlepunched textile laminated to strands on both sides of the geonet.
[0020] In still another form of this aspect of the present invention, the geocomposite is stored in a roll having X number of layers with each strand of the first layer of strands being rolled X times.
[0021] In another form of this aspect of the present invention, the geotextile is spun-bonded or needlepunched non-woven textile laminated to strands on both sides of the geonet.
[0022] In still another aspect of the present invention, a landfill includes alternating layers of fill and geocomposites, with the geocomposites each disposed beneath a layer of fill to facilitate draining of liquid from the landfill. The geonet has a length substantially greater than its width with a geotextile bonded to at least one side. The geonet has no more than first and second layers of strands, where a first plurality of substantially parallel strands extends in the lengthwise direction and defines the first layer of strands, and a second plurality of substantially parallel strands is disposed on top of the first plurality of strands and defines the second layer of strands. The second plurality of strands are at an angle relative to the first plurality of strands, and the first and second plurality of strands are substantially incompressible and secured to one another at crossover locations.
[0023] In one form of this aspect of the present invention, at least one of the first and second plurality of strands is substantially round in cross-section.
[0024] In another form of this aspect of the present invention, the strands are polyethylene (PE).
[0025] In yet another aspect of the present invention, a method of making a geonet for use in a geotechnical construction site includes first providing a mold for extruded material. The mold includes a first mold member having an outer boundary cylindrical about an axis and defining a first plurality of strand defining openings open at the outer boundary and spaced around the outer boundary, and a second mold member concentric with the first mold member and having a cylindrical inner boundary defining a second plurality of strand defining openings open at the inner boundary and spaced around the inner boundary. Further to the method, extruded material is forced through the first and second plurality of strand defining openings while one of the first and second mold members is stationary and the other of the first and second mold members rotates to define a cylindrical net with the strands defined by the openings of the one of the first and second mold members each extending substantially parallel to the axis and the strands defined by the openings of the other of the first and second mold members spiraling around the cylindrical net. According to the method, the strands defined by the other of the first and second mold members are then cut along a line substantially parallel to the axis, the cut cylindrical net is flattened to generally orient the strands in a plane, and the flattened net is rolled whereby the strands defined by the one of the first and second mold members are coiled.
[0026] In one form of this aspect of the present invention, the openings of the first plurality of openings are open to openings of the second plurality of openings when the openings of the first and second plurality of openings are aligned along a radius of the axis during relative rotation of the first and second mold members.
[0027] In another form of this aspect of the present invention, one of the first and second plurality of openings is substantially rectangular in cross-section.
[0028] In still another form of this aspect of the present invention, the other of the first and second mold members rotates at a rate whereby the strands molded thereby are at an angle of 45° to 70° relative to the strands molded by the one of the first and second mold members.
[0029] In yet another aspect of the present invention, a method of making a landfill includes alternating layers of fill and geonets so that the geonets are each disposed beneath a layer of fill to facilitate draining of liquid from the landfill. The method includes rolling a geonet made according to the previously described aspect of the invention beneath each layer of landfill in the direction of expected drainage flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a perspective view of one embodiment of a geonet according to the present invention;
[0031] FIG. 2 is a cross-sectional view of the one embodiment of a geonet according to the present invention, taken along line 2 - 2 of FIG. 1 ;
[0032] FIG. 3 is an enlarged cross-section view of a geocomposite according to the present invention including a geotextile on both the top and bottom of the geonet of FIGS. 1-2 , oriented according to line 3 - 3 of FIG. 1 ;
[0033] FIG. 4 is a perspective view of another embodiment of a geonet according to the present invention;
[0034] FIG. 5 is a cross-sectional view of the geonet of the second embodiment, taken along line 5 - 5 of FIG. 4 ;
[0035] FIG. 6 is an enlarged side view of a geocomposite according to the present invention including a geotextile on both the top and bottom of the geonet of FIGS. 5-6 , oriented according to line 6 - 6 of FIG. 4 ;
[0036] FIG. 7 is an end view of a mold structure which may be used to make the geonets of FIGS. 4-5 ;
[0037] FIG. 8 is a perspective view illustrating the unwrapping of the molded cylindrical geonet to a flat longitudinal layer;
[0038] FIG. 9 is a partial view of another mold structure which may be used to make other geonet configurations embodying some aspects of the present invention; and
[0039] FIG. 10 is a cross-section of a landfill in which the geocomposite of the present invention is used.
DETAILED DESCRIPTION OF THE INVENTION
[0040] One embodiment of a geonet 12 according to the present invention is shown in FIGS. 1-2 . The geonet 12 consists of substantially incompressible longitudinal strands 14 (e.g., formed of polyethylene [PE], including but not limited to high density polyethylene [HDPE]), including a lower set of a plurality of substantially parallel strands 14 a and an upper set of a plurality of substantially parallel strands 14 b. Advantageously, one set of strands 14 a extends parallel to the longitudinal direction of the geonet 12 , and the other set of strands 14 b is at an angle of 45° to 70° relative to the longitudinal strands 14 a so that a crisscrossed grid 20 is formed (see FIG. 1 ).
[0041] It should be understood that as used herein, “substantially incompressible” is meant to refer to materials such as HDPE which, though susceptible to bending, breaking, fracture and/or creep, does not appreciably compress in the vertical direction when vertical forces are applied.
[0042] At their overlapping intersection, the strands 14 a, 14 b are suitably secured together whereby a relatively rigid geonet 12 is provided in the plane of the geonet 12 (i.e., the geonet 12 is substantially rigid against compressive forces directed along the plane of the geonet 12 , while still providing some flexibility for bending when laid on uneven ground).
[0043] In accordance with this embodiment, the lower set of strands 14 a of the geonet 12 are substantially round in cross-section with connected areas 24 at the overlapping intersections. Such a cross-section provides a reduced risk of failure due to the strands 14 a laying or folding over due to the pressures encountered in use. Advantageously, the diameter of the strands 14 a, 14 b may, for a given design use, be substantially the same as the longer dimension of the prior art flat strands.
[0044] A geocomposite 28 incorporating the geonet 12 of FIGS. 1-2 is shown in FIG. 3 . In the illustrated geocomposite 28 , geotextiles 30 , 32 (such as, e.g., non-woven needlepunched geotextiles, spun-bonded or laminated textiles, as are known in the art) are suitably secured to both sides of the geonet 12 , such as by heat laminating.
[0045] A second embodiment of a geonet 12 according to the present invention is shown in FIGS. 4-5 . (Comparable reference numerals to those used in describing the FIGS. 1-2 embodiment are used herein, with similar but modified components having the same reference numeral with prime [′] added [e.g., 12 in FIGS. 1-2 is 12 ′ in FIGS. 4-5 ]).
[0046] The geonet 12 ′ consists of substantially incompressible longitudinal strands 14 ′ (e.g., formed of polyethylene [PE], including but not limited to high density polyethylene [HDPE]), including a lower set of a plurality of substantially parallel strands 14 a ′ and an upper set of a plurality of substantially parallel strands 14 b ′. Advantageously, one set of strands 14 a ′ extends parallel to the longitudinal direction of the geonet 12 ′, and the other set of strands 14 b ′ is at an angle of 45° to 70° (advantageously 60°) relative to the longitudinal strands 14 a ′ so that a crisscrossed grid 20 ′ is formed (see FIG. 4 ).
[0047] At their overlapping intersection, the strands 14 a ′, 14 b ′ are suitably secured together whereby a relatively rigid geonet 12 ′ is provided in the plane of the geonet 12 ′ (i.e., the geonet 12 ′ is substantially rigid against compressive forces directed along the plane of the geonet 12 ′, while still providing some flexibility for bending when laid on uneven ground).
[0048] In accordance with this embodiment, both the lower and upper sets of strands 14 a ′, 14 b ′ are substantially rectangular in cross-section with connected areas 24 ′ at the overlapping intersections. Advantageously, the height of the strands 14 a ′, 14 b ′ may, for a given design use, be substantially the same as the longer dimension of the prior art flat strands.
[0049] A geocomposite 28 ′ incorporating the geonet 12 ′ of the FIGS. 4-5 is shown in FIG. 6 . In the illustrated geocomposite 28 ′, geotextiles 30 , 32 are suitably secured to both sides of the geonet 12 ′, such as by heat laminating.
[0050] FIG. 7 illustrates an exemplary mold structure through which extruded material may be forced (pulled) to advantageously form the geonet 12 ′ of FIGS. 4-5 . Specifically, the geonet 12 ′ may first be formed in a tubular shape with a cylindrical inner mold 60 having rectangular strand defining openings 64 spaced around the exterior boundary of the mold 60 . An outer mold 70 is supported for rotation around the central axis 72 and includes strand defining openings 74 spaced around its inner cylindrical surface.
[0051] As generally illustrated in FIG. 8 , the formed cylindrical geonet 80 may be longitudinally cut as it is molded with the geonet 80 then spread out to a suitable flat configuration ( 82 ) having a width substantially equal to the diameter of mold 60 times π (pi) and virtually any selected length in the direction of arrow 84 . It should be appreciated that maintaining mold 60 stationary while rotating mold 70 during molding will result in the desired longitudinal orientation of strands 14 a ′ in the direction of arrow 84 and the angled orientation of strands 14 b ′. Desired significant lengths of the geonet 80 may be cut, geotextiles 30 ′, 32 ′ added as desired, and then rolled into a coil for convenient transport and handling. When rolled, the geonet 80 is in a coil having X number of layers (as measured outwardly from the coil center) with each of the longitudinal strands 14 a ′ being rolled X times (meaning that each longitudinal strand 14 a ′ is coiled from the center of the roll to the outer layer of the roll).
[0052] FIG. 9 shows an alternate mold configuration, in which the inner mold 60 ′ includes round openings 64 ′ and the outer mold 70 ′ also includes round openings 74 ′, such as may be used to provide round strands in both sets of strands. Round strands have been found to be particularly advantageous in some applications as disclosed in U.S. patent application Ser. No. 11/271,396, filed Nov. 10, 2005, the disclosure of which is hereby incorporated by reference. It should, however, be understood that various advantages of the present invention could be obtained with a wide variety of strand shapes. For example, round openings in the inner mold and rectangular openings in the outer mold would be used to produce the geonet 12 illustrated in FIGS. 1-2 .
[0053] FIG. 10 illustrates, in cross-section, a landfill 90 in which geocomposites 28 according to the present invention may be advantageously used. As the landfill is made, a first layer of geocomposites 28 a is laid down on the surface of the area on which the landfill 90 is being formed. Of course, the area being covered may be extremely large, and therefore more than one section or roll of geocomposite 28 a will typically be required to cover the entire area at each layer. In accordance with this aspect of the invention, the geocomposite 28 a is rolled in the direction of expected fluid flow so that the longitudinal strands 14 a are oriented in the direction of expected fluid flow.
[0054] Fill 92 a will then be placed on top of the geocomposite 28 a to a desired depth such as is known in the art, and then a second layer of geocomposites 28 b is then laid down on that area in the orientation of expected fluid flow for that layer. Further layers of fill 92 b - 92 e and geocomposites 28 c - 28 e are similarly added according to the design of the landfill 90 . As is known to those skilled in the art, geocomposites 28 a - 28 e such as illustrated may be used to facilitate fluid flow through the landfill 90 . Moreover, other structures, such as pumps and vertical and horizontal pipes, may also be used in conjunction with such geocomposites 28 a - 28 e if desired to intentionally circulate leachate through the landfill and thereby facilitate stabilization of the landfill 90 so that it may thereafter be returned to other productive uses more quickly. Further, geocomposites 28 only about 0.200 inch thick may be used, for example, in place of twelve inch layers of sand and aggregate, thereby requiring much less height and concomitantly having less environmental impact and/or allowing for more fill (e.g., waste in a landfill).
[0055] It has been found that desired high transmissivities may be provided by geonets having the strands configured according to the present invention, with transmissivities maintained in the direction of the bottom strands 14 a, 14 a ′ under the wide range of conditions which may be encountered (including interface, gradient, seat time and pressure). Moreover, this configuration allows for extremely high flow rates while at the same time using a very low weight per unit are of the material for such geonets 12 , 12 ′. For example, at higher pressures such as 10,000 pounds per square foot, such as may be encountered in site designs involving several hundred thousand to over a million square feet and projected overburden heights of zero to over two hundred feet, significantly greater fluid flow along the generally horizontal geonet 12 may be provided, and/or significantly less geonet materials may be used, than with geonets not embodying the present invention. Thus, geocomposites 28 such as described herein may be advantageously used particularly in large landfills where they are subjected to high pressures over long periods of time. However, it should further be understood that geonets 12 and geocomposites 28 according to the present invention, though advantageously usable in geotechnical construction sites such as landfills 90 as described above, may also be advantageously usable in a wide variety of geotechnical construction sites, including not only common horizontal orientations facilitating drainage over a site but also vertical orientations such as in mechanically stabilized earth walls.
[0056] Still other aspects, objects, and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims. It should be understood, however, that the present invention could be used in alternate forms where less than all of the objects and advantages of the present invention and preferred embodiment as described above would be obtained.
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A geonet having a length substantially greater than its width and including no more than first and second layers of strands. A first plurality of substantially parallel strands extends in the lengthwise direction and defines the first layer of strands, and a second plurality of substantially parallel strands is disposed on top of, and at an angle relative to, the first plurality of strands and defines the second layer of strands. The first and second plurality of strands are substantially incompressible and secured to one another at crossover locations. Geocomposites include geotextile bonded to at least one side of the geonet. The geonets/geocomposites are laid in geotechnical construction sites in the direction of expected drainage flow.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a self-propelled building machine, in particular a road cutting machine or a surface miner, having a machine frame and a chassis that comprises running gear that rests on the ground below. Furthermore, the present invention relates to a method for operating such a building machine.
2. Description of the Prior Art
Self-propelled building machines of the above type comprise a working device that is arranged on the machine frame, which comprises a working roller that has to be brought into contact with the ground to work the ground below. This working roller can be in the form of a milling or a cutting roller, by means of which, for example, damaged layers of road can be removed, or mineral resources can be extracted from the ground.
In known road cutting machines and surface miners, the working roller is located in a roller housing which is open at the bottom, that is closed by a pressure element arranged in the direction of working in front of the working roller and by a stripper device arranged in the direction of working behind the roller. On at least one side, the roller housing is closed by a plate extending in the direction of working, which is designated as an edge protection.
The height of the machine frame of the known building machines can be adjusted in relation to the surface of the ground if the machine is positioned with the running gear resting on the ground. For this purpose, such building machines comprise a device for adjusting the height of the machine frame, which is activated by a control unit. As the working device is arranged on the machine frame, this adjustment affects not only the height of the machine frame, but also that of the working roller. In addition, the height of the working device can be adjusted in relation to the machine frame.
During the operation of the building machine, the height of the machine frame is set in such a way that the cutting roller of the working device penetrates the ground. At the same time, if necessary, the height of the pressure element and the stripper device and also of the edge protection can be adjusted in relation to the machine frame. In general, the pressure element, the stripper device and the edge protection are mounted in a floating manner, so that the height can be adjusted independently. This has the effect that the pressure element, the stripper device and the edge protection can follow the surface of the ground and the roller housing is always closed at the bottom.
When adjusting the working depth of the working device, the problem arises that, when the machine frame is lowered, the working roller does not penetrate the ground quickly enough. The speed at which the working roller penetrates the ground is determined by the condition of the working roller, the condition of the ground and the weight of the building machine. If the working roller does not penetrate the ground quickly enough and the machine frame is lowered further, there is a risk that the working roller will sink too deep into the ground. This problem is known in practice as a “sighting hole”.
It can also happen during the operation of the building machine that the edge protection, the stripper device or the pressure element, which are height-adjustably suspended or mounted on the machine frame, can become jammed while being adjusted. If the machine frame is lowered with the edge protection, the stripper device or the pressure element in a jammed state, it can happen that the building machine jerks backwards onto the running gears or the working roller if the jamming is suddenly released. This can damage the working roller or the drive train, for example.
SUMMARY OF THE INVENTION
It is therefore the aim of the present invention to propose a self-propelled building machine in which an uncontrolled lowering of the machine is prevented when the working depth of the working device is adjusted. A further aim of the present invention is to propose a method for operating a building machine whereby an uncontrolled lowering of the machine is avoided.
According to the present invention, this aim is achieved by the features contained in the independent claims of the patent. The objects of the dependent claims relate to preferred embodiments of the invention.
The building machine according to the present invention provides for an operating mode to adjust the working depth of the working device, in which the machine frame is lowered. This operating mode is characterised by the fact that although the working device is driven, the machine is at a standstill. In this respect, this operating mode differs from the operating mode in which the working device is driven so that the ground can be worked during the forward movement of the machine.
The basic principle of the present invention lies in the fact that, in order to prevent any uncontrolled sinking of the building machine in the above operating mode, the imposed weight exercised by the building machine on the running gears has to be measured, whereby it is assumed that the uncontrolled sinking of the building machine occurs if the running gears are not resting on the ground when the cutting roller is lowered.
The machine frame of the building machine is lowered as a result of the relative movement of the running gears and the machine frame. If the machine frame is to be lowered at a faster rate than that at which the working roller penetrates the ground, the running gears are lifted off the ground, so that the imposed weight is less than a predetermined threshold weight measured against the imposed weight of the building machine and the running gears on the ground. In practice, the imposed weight falls to zero at the moment at which the running gears are lifted off the ground and all control over the lowering process is immediately lost.
In the building machine according to the present invention and the method according to the present invention, the lifting of the running gears is identified by measuring the imposed weight, whereby depending on the imposed weight, the lowering action will be either controlled or uncontrolled. If the lowering action is uncontrolled, appropriate steps must be taken.
In principle, the imposed weight can only be measured on one of the running gears, on a part of the running gears or on all height-adjustable running gears. Preferably, the imposed weight is measured on all height-adjustable running gears, whereby preferably an uncontrolled lowering can be determined in relation to the imposed weight if at least one of the running gears is lifted off the ground.
For the purpose of the present invention, the term “running gear” is understood to signify any means by which the building machine rests as intended on the ground. The running gears can be, for example, wheels or crawler tracks.
The building machine according to the present invention is characterised by a measuring device, which comprises a means for measuring the imposed weight applied by the building machine on at least one of the running gears or alternatively a physical value correlating to the imposed weight. In practice, the calculation of a value correlating to the imposed weight enables a simple calculation to be made of the measurement using methods known to the state of the art.
Furthermore, the building machine according to the present invention comprises an evaluation device, which, according to the measured imposed weight or the physical value correlating to the imposed weight, generates a signal in the operating mode of the lowering of the building machine, referred to below as a control signal, that signals an unwanted and uncontrolled lowering of the building machine, if the imposed weight reaches or falls below a predetermined threshold value, and/or generates a signal that signals a controlled lowering of the building machine if the imposed weight exceeds a predetermined threshold value.
In this connection, the term “control signal” is understood to represent any value, by which the information of a controlled lowering or an uncontrolled lowering is indicated. In a preferred embodiment, electrical signals are used for the transmission of information, whereby an electrical signal is understood to be either a digital or an analogue signal.
In a preferred embodiment of the present invention, the control unit for adjusting the height of the machine frame functions together with the evaluation unit in such a way that in the operating mode of the lowering of the building machine any further lowering of the building machine is prevented if the control unit receives a control signal from the evaluation unit indicating that an uncontrolled lowering of the building machine has been signalled. Alternatively, it is also possible not to carry out any height adjustments until the control unit has received a control signal from the control unit indicating a controlled lowering of the building machine.
A further preferred embodiment provides for a signalling unit having an acoustic and/or a visual signal and/or a tactile signal emitter, with the signalling unit emitting an acoustic and/or a visual and/or a tactile signal if the signalling unit receives a signal from the evaluation unit indicating an uncontrolled lowering of the building machine. Alternatively a controlled lowering can be signalled.
The automatic interruption or release of the height adjustment and the signalling of an uncontrolled or a controlled lowering can also be combined, so that the machine operator is notified of an action taking place in the machine control system.
For the purpose of the invention it is not important which parts of the building machine are brought into contact with the ground when the height of the machine frame is being adjusted. In practice, there is above all the danger that the building machine with the working roller is placed on the ground before the working roller has been able to penetrate the ground.
However, if the working roller is arranged in a roller housing that is open at the bottom, and is closed on at least one side by a height-adjustable edge protection and/or is closed on the front side in the direction of working by a height-adjustable pressure element and/or is closed on the rear side by a height-adjustable stripper device, both the method according to the present invention and the device according to the present invention will prevent the building machine from falling onto the running gears or the working roller if these parts of the working device should become jammed and are then released as the machine frame is lowered.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, different embodiments of the present invention are described with reference to the figures.
These show:
FIG. 1 a side aspect of a road cutting machine,
FIG. 2 a block diagram of the control unit, the measuring device, the evaluation unit and the signalling unit of the road cutting machine,
FIG. 3 a greatly simplified schematic representation of a lifting column and a running gear of the road cutting machine, whereby the running gear rests on the ground and
FIG. 4 a greatly simplified schematic representation of a lifting column and a running gear of a road cutting machine, with the running gear lifted off the ground.
DETAILED DESCRIPTION
FIG. 1 shows the side aspect of a road cutting machine, which represents a small cutting machine. The road cutting machine comprises a machine frame 1 , which is supported by a chassis 2 . The chassis comprises running gears 3 , which include one front wheel 3 A and two rear wheels 3 B. In FIG. 1 , only the rear right-hand wheel 3 B is visible. In known building machines, the chassis can comprise, for example, crawler tracks instead of wheels.
The cutting machine comprises a working device 4 , which is arranged on the machine frame 1 . The working device 4 comprises a working roller, which is in the form of a cutting roller. The cutting roller, which is not visible in FIG. 1 , is arranged in a cutting roller housing 6 of the working device. The cutting roller housing 6 on the left and right side of the direction side of working A is enclosed by an edge protection 7 . In FIG. 1 only the edge protection 7 in the direction of working is visible. At the front side in the direction of working A, the cutting roller housing 6 is enclosed by a pressure element 8 and at the rear side in the direction of working A by a wiper device 9 . Above the cutting roller housing 6 , there is the control stand for the cutting machine with the operator's seat 11 and the control panel 12 .
The height of the machine frame 1 of the cutting machine is adjustable in relation to the surface 13 of the ground 14 . The device 15 to adjust the height of the machine frame comprises in the direction of working A a left-hand rear lifting column and a right-hand rear lifting column, which support the machine frame. The left-hand lifting column is attached to the left-hand running gear 3 and the right-hand lifting column is attached to the right-hand running gear 3 . FIG. 1 shows only the right-hand lifting column 16 . When the running gears 3 are resting on the ground 14 , the machine frame 1 is raised by the outward and return movements of the lifting columns 16 , which are controlled by a control unit 17 . As the working device 4 is attached to the machine frame 1 , the height of the cutting roller above the surface of the ground can be adjusted by adjusting the height of the machine frame. By adjusting the height of the machine frame, the height of the edge protection 7 , the pressure element 8 and the wiper device 9 , which are also arranged on the machine frame are also adjusted. However, the height of the edge protection, the pressure element and the wiper device is also adjustable in relation to the machine frame. The devices to adjust the height of the edge protection, the pressure element and the wiper device, which are not shown in FIG. 1 , ensure a floating position to the edge protection, the pressure element and the wiper device, in which the edge protection, the pressure element and the wiper device rest on the ground in a floating manner.
The control device 17 comprises an operating mode, in which the machine frame 1 of the cutting machine is lowered to adjust the cutting depth. This process is also known as “sighting”. The machine operator can engage this operating mode, for example, by activating a control on the control panel 12 , for example a press-button or a switch.
In addition to the control unit 17 to control the device 4 to adjust the height of the machine frame with the left-hand and the right-hand lifting column 16 , the cutting machine also comprises a measuring device 18 , an evaluation unit 22 and a signalling unit 30 , which are shown in FIG. 2 together with the lifting columns 16 in a block diagram. All units can form separate building elements or can be a part of the central control system of the building machine.
The lifting columns 16 are hydraulically operated. The hydraulic system is not shown in FIG. 2 . By means of the control unit 17 , the hydraulic lifting columns 16 can be operated in such a way that the lifting columns are moved inwards and outwards allowing the machine frame 1 to be raised or lowered when the running gears 3 are resting on the ground.
The measuring device 18 comprises means 19 to measure the imposed weight of the cutting machine on the running gears. The means for measuring the imposed load include a first measurement indicator 19 A for measuring the imposed weight on the rear left-hand running gear and a second measurement indicator 19 B for measuring the imposed weight on the rear right-hand running gear. These are described individually in detail below with reference to the FIGS. 3 and 4 .
The measuring device 18 is connected to the evaluation unit 22 via a data connection 20 , which is in turn connected via a data connection 21 to the control unit. The measurement indicators 19 A, 19 B generate signals on the basis of the imposed load. In simple terms, the measurement indicators generate a signal if the running gear is resting on the ground and it generates no signal if the running gear is not resting on the ground or vice versa. However, the measurement indicators can also generate a signal that is proportional to the size of the imposed weight, for example an alternating voltage, with the amplitude increasing in direct proportion to the imposed weight. The evaluation unit 22 compares the output signal from the first and the second measurement indicators 19 A, 19 B respectively with a threshold value, which, in the simplest case is zero. If the output signal from the first indicator is equal to zero and/or the output signal from the second measurement indicator is equal to zero, the evaluation unit 22 generates a control signal indicating an uncontrolled lowering of the building machine indicating that at least one of the two rear running gears is not resting on the ground. On the other hand, the evaluation unit 22 does not generate the control signal if the output signal from the first and second measurement indicators is greater than zero, i.e. both running gears are resting on the ground. In this case, the evaluation unit 22 can also generate a second control signal that indicates a controlled lowering of the building machine. However, a signal evaluation of this type is to be understood as being only one of a number of possible embodiments, as the generation of corresponding signals and their evaluation belongs as such to the state of the art.
The signalling unit 30 comprises an acoustic and/or a visual and/or a tactile signal emitter 20 A, 20 B, 20 C. If the signalling unit 30 receives a control signal from the evaluation unit 22 indicating an uncontrolled lowering of the building machine during the operating mode selected by the machine operator for adjusting the cutting depth, the signalling unit sends the machine operator an acoustic and/or a visual and/or a tactile signal, so that he can take the necessary steps to restore the machine to a controlled state.
By way of example, it is assumed that, in the operating mode for adjusting the cutting depth, the machine operator lowers the machine frame more quickly that the cutting roller can penetrate the ground. Consequently, at least one of the two running gears loses contact with the ground, so that the evaluation unit 22 generates a signal indicating an uncontrolled lowering of the building machine. This is immediately communicated to the machine operator by means of the signalling unit 30 . The machine operator can then restore a controlled lowering by interrupting the lowering of the machine frame immediately, although he can also raise the machine frame again if this should be necessary.
A further embodiment of the present invention provides for the fact that not only the evaluation unit 22 but also the control unit 17 for adjusting the height of the machine frame 1 receives a control signal indicating an uncontrolled sinking. The control unit is configured in such a way that, after a control signal is received, it can prevent or interrupt any adjustment to the height by the lifting columns 16 . Additionally, the signalling unit 30 can communicate the automatic correction to the machine operator. Moreover, after receiving the control signal, the control unit 17 can intervene further in the control of the machine in order to return the machine to a controlled state, for example, it can lower a running gear 3 that has already been slightly raised until the evaluation unit receives a signal indicating a controlled lowering. These corrections can be made by the control unit on the basis of a predetermined program. This ensures that an uncontrolled lowering can be corrected immediately if the correction is not carried out manually by the machine operator.
FIGS. 3 and 4 show in a simplified schematic representation one of the two rear lifting columns 16 and the respective running gear 3 , in which one wheel is supposed to be resting on the ground. The lifting column 16 comprises a piston/cylinder arrangement 23 , which is arranged in an upper and a lower conductor pipe 24 , 32 , that concentrically encloses the piston/cylinder arrangement 23 . The upper conductor pipe 24 is connected to the area of the lower part of the machine frame 1 , which is only notionally indicated. On the upper side, the upper conductor pipe 24 is closed by means of a cover 25 , which comprises a bore-hole 26 . The piston 23 B of the piston/cylinder arrangement 23 has, at its upper side, a guiding piece 28 , that can be longitudinally displaced along the bore-hole 26 of the cover 25 . A plate 29 is connected to the upper side of the guiding piece 28 , the diameter of which is greater than that of the bore-hole in the cover. Consequently, the cylinder 23 A can move in both an upwards and a downwards direction in the conductor pipes 24 , 32 within the predetermined area, whereby the size of the gap 31 between the lower side of the plate 29 and the upper side of the lid 25 increases or reduces. When the running gear 3 rests on the ground 14 , the cylinder 23 A is supported with its upper side against the lower side of the cover 25 . FIG. 3 shows the lifting column 16 , when the running gear 3 rests on the ground 14 , while FIG. 4 shows the lifting column once the running gear has lost contact with the ground.
The piston/cylinder arrangement 23 may also be referred to as a length adjustable holder 23 . The upper conductor pipe 24 and cover 25 of the lifting column 16 may be described as fixed components of the lifting column fixed relative to the machine frame 1 . In FIG. 3 the length adjustable holder 23 is shown in a first position relative to the fixed components 24 and 25 , in which the length adjustable holder 23 supports the fixed component 25 of the lifting column 16 . In FIG. 4 the length adjustable holder 23 is shown in a second position relative to the fixed components 24 and 25 , in which the length adjustable holder does not support the fixed component 25 .
In the present embodiment, the measurement indicator 19 is, for example, an inductive or a capacitive proximity switch that measures the distance between the lower side of the plate 29 and the upper side of the cover 25 . However, instead of the proximity switch an electrical switching contact can be used, which is closed or opened when an imposed weight is applied by the building machine onto the running mechanism. Together with a distance gauge, the play-free mounting of the piston/cylinder arrangement 23 allows a simple and a reliable means of detecting any uncontrolled lowering of the machine.
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A self-propelled building machine, especially a road cutting machine or a surface miner, has a machine frame and a chassis, comprising running gears resting on the ground. In addition, the present invention relates to a method for operating such a building machine. In an operating mode for adjusting the working depth of the working device the imposed weight applied by the building machine on the running gear is measured, whereby depending on the imposed weight either a controlled or an uncontrolled lowering of the building machine is indicated. A measuring device comprises a sensor for measuring the weight imposed by the building machine on at least one of the running gears. Depending on the measured imposed weight, a signal is generated indicating an uncontrolled lowering of the building machine, if the imposed weight falls short of a predetermined value and/or a signal indicating a controlled lowering of the building machine is generated if the imposed weight reaches or exceeds a predetermined threshold value.
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The present invention relates to a method to minimize corrosion and particularly build-up in sections, including associated feed conduits, of a flue-gas system where significant amounts of moisture and/or sulfuric acid are present.
BACKGROUND OF THE INVENTION
In most flue-gas systems, for safety and environmental reasons, as a means of conserving heat, the flue-gas leaving the furnace at relatively high temperatures is passed through a variety of treatment devices before escaping into the atmosphere. Among these devices are, usually in sequence, a boiler or heater, a precipitator, a gas/gas heater, and a scrubber, the flue-gas returning to the gas/gas heater on its way to the stack. The temperature of the flue-gas decreases as the gas passes through the system, and in the course of that temperature decrease moisture, as water and often as sulfuric acid, comes into being. It has long been customary to add substances to the flue-gas to minimize or prevent corrosion of the exposed surfaces of the system. (My prior U.S. Pat. No. 4,842,617 of Jun. 27, 1989 entitled “Combustion Control By Addition of Magnesium Compounds of Particular Particle Sizes”, and U.S. Pat. No. 5,034,114 of Jul. 23, 1991 entitled “Acid Neutralizing Composition Additive With Detergent Builder” are representative of the use of such additives.) The corrosive action of sulfuric acid on exposed surfaces of the system is obviously undesirable and it is therefore common to add such substances as limestone or magnesium oxide to the system to neutralize the sulfuric acid. Because a solid/liquid reaction rate is generally slow, relatively large amounts of such additives must be provided. They are usually pneumatically injected into the affected portion of the system through conduits, usually in the form of pipes, using pressurized air as the vehicle to transport the additives through the conduit to the injection location in the system. The act of compressing air generates both heat and moisture, and hence the pressurized air which does the conveying is usually both moisture-laden and hot. Movement of the pressurized additive through the conduits results in some condensation of the moisture on the conduit surface and this enhances the tendency of the solid additives to stick to and build-up on those surfaces. As a result it is periodically necessary to take the injection equipment off line for cleaning, a process which is itself costly and time consuming, and while the injection equipment is off line no anti-corrosion additive is fed to the system, thus increasing the likelihood of corrosion.
When the system is provided with a scrubber the flue-gas emanating from the scrubber has a comparatively high moisture content and a comparatively low temperature, thus leading to the condensation of comparatively large volumes of moisture, significantly including sulfuric acid in its liquid form because its temperature is below its dew point. When, as is usually the case, the output from the scrubber is fed back to the gas/gas heater the moisture content of the flue-gas becomes a significant corrosion-producing factor.
SUMMARY OF THE INVENTION
I have discovered that the build-up of additives such as, typically, limestone or magnesium oxide in the conduits conveying those additives to the system can be significantly reduced and the anti-corrosion effect of the limestone, magnesium oxide or other anti-corrosion additives can be enhanced, by including with the additives, particularly as they are conveyed through their conduit and enter the system, and also importantly while the additives are in the gas/gas heater, relatively small amounts of a generally inert bulking agent in expanded form. Expanded vermiculite and expanded perlite are representative of such substances, which exhibit a crystal structural change to a “popcorn” type expanded material when heated to elevated temperatures, usually of 800° F. or higher, and retaining that expanded characteristic after the high temperature has been reduced. The expansion is normally on the order of 2 to 5 times the original volume.
The precise mechanism by which these expanded materials perform their good offices when thus used in flue-gas systems is not known for certain, but is believed that it is because they may be able to absorb within their interstices substantial quantities of the moisture which is present without congealing or settling out.
Moisture appears to be a factor in forming accumulations of the additive on affected surfaces of a flue-gas system and in particular on the surfaces of the additive feed conduits, and the reduction in the amount of available moisture when the method of the present invention is carried out appears to be responsible for a significant lessening of the conduit build-up, as well as a lessening of corrosion throughout the treated portions of the system.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 discloses diagrammatically a typical flue-gas system in which the method of the present invention is particularly useful.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A typical flue-gas system such as is shown in FIG. 1 comprises a furnace or boiler 2 where steam is generated. Ambient air enters the system at 4 and passes through a primary air heater 6 in which it is heated to perhaps 150° F. and it then enters the furnace 2 to combine with fuel for combustion purposes. A waste product from the combustion in the furnace 2 is the flue-gas which exits the furnace at 8 at a temperature of perhaps 800° F. The flue-gas passes through the air heater 6 , providing the means for the initial heating of the ambient air, and the flue-gas which leaves the air heater 6 , at 10 , will have lost a great deal of its heat and be at a temperature of about 350°-400° F. It then passes into an electrostatic precipitator 12 in which certain impurities are removed, and it escapes from the precipitator 12 at 14 at a further reduced temperature of about 200°-275° F. Because of its reduced temperature the flue-gas may now have a significant moisture content of perhaps 5-15%. The flue-gas then goes into the upper portion 16 A of the gas/gas heater 16 from which it escapes to point 18 at a temperature of about 200°-225° F. and it then passes through a scrubber 20 which it leaves at a temperature of perhaps 100°-150° F. and with a moisture content of perhaps as high as 40-50%. The gas is then fed back through the lower portion 16 B of the gas/gas heater 16 and escapes through the stack at 24 .
The gas/gas heater 16 has structural parts which rotate from the upper portion of 16 A to the lower portion of 16 B on a continuous basis. It will be apparent that exposed surfaces of the gas/gas heater 16 , and particularly those surfaces thereof which at any given moment are in the lower portion 16 B of the heater, are very susceptible to acid corrosion because of the high moisture content to which they are subjected. From the point of view of minimizing corrosion in the gas/gas heater 16 it is at the area 14 immediately up-stream of the gas/gas heater 16 where the usual corrosion-minimizing additives are injected into the system, as indicted by the arrow 26 .
The susceptibility of the gas/gas heater 16 to corrosion can perhaps be best appreciated by considering that a scrubber 20 more easily and effectively absorbs impurities from the flue-gas when the flue-gas is at or below its dew point, and when the flue-gas exits the scrubber 20 its temperature is below the dew point to an even greater degree, thereby increasing its moisture content and making corrosion more likely. Also, because structural parts of the gas/gas heater 16 rotate sequentially through the upper and lower portions 16 A and 16 B thereof, they are constantly subjected to variations in temperature, and the constant heating and cooling of the structural parts of the gas-gas heater 16 , coupled with the resultant high moisture content of the flue-gas as that passes through the heater, produces a situation ideal for corrosion and for deposit build-up.
Also, as has been pointed out above, the pressurized feeding of the conventional anti-corrosion additive facilitates build-up in the conduit feeding those additives to the system. The additives are preferably injected into the system between the precipitator 12 and the gas/gas heater 16 , as indicated by the arrow 26 , so that they can perform their desired action where that action is most needed, to wit, in the gas/gas heater 16 .
The conventional anti-corrosion additives are usually basifying agents which act to neutralize the acidic constituents, usually sulfuric acid, of the flue-gases. Typically such basifying agents are calcium oxide, calcium hydroxide, calcium carbonate, dolomite, dolomitic lime, lime, calcium hydrate, limestone, magnesium oxide, magnesium hydroxide, magnesium carbonate, potassium or aluminum oxides, hydroxides or carbonates, as well as bicarbonates of each, i.e., calcium, magnesium, potassium or aluminum, as well as combinations thereof such as calcium/magnesium oxides and hydroxides.
Because of the apparent slowness of the reaction between these basifying additives and the sulphur or other oxides that they are designed to neutralize, those additives must be provided in relatively large quantities, well in excess of the stoichiometric amount required to neutralize the acidic constituents. As a result the problem involved in preventing build-up in the conduits through which those basifying agents are fed is intensified.
According to the present invention the build-up problem, particularly in the additive conduit, is significantly improved and the corrosion problem, particularly in the gas/gas heater 16 , is minimized when there is combined with the normal additive a generally inert bulking agent in expanded form, such as expanded perlites, vermiculites and other mineral substances that have undergone a physical expansion when exposed to elevated temperatures. Such minerals, when heated to high flame temperatures, alter their physical characteristics by greatly expanding, in a manner reminiscent of popcorn.
The effectiveness of the use of expanded bulking agents such as expanded vermiculite in minimizing build-up is shown by the following laboratory demonstration. In each of the following samples a mixture of 30 cc of water, 3 cc of diluted sulfuric acid (5 cc concentrated sulfuric acid in 25 cc water) and 2 gm of powdered additive was observed at room temperature after stirring and after incubation at 130° C. for three hours, and gave the results set forth in Table I.
TABLE I
Results
At Room
Sample
Composition
Temperature
After Incubating
No.
of Additive
after Stirring
at 130° for 3 hrs.
BB-1
Magnesium Oxide (92%)
Settling
Hard layer-
difficult to
break apart.
Tenacious.
BB-2
75% MgO (as in BB-1)
Dispersed
Soft-easily
25% “Expanded” Ver-
penetrated.
miculite
BB-3
75% MgO (as in BB-1)
Settled
Somewhere between
25% Regular-micron
BB-1 and BB-2,
Vermiculite
but on hard side,
and much closer
to BB-1.
BB-6
75% Lime
Milky
Crusty (somewhat
-i.e., hard
moist). Tena-
to observe if
cious.
there is any
degree of
settlement
BB-7
75% Lime
Dispersed
Crushable
25% “Expanded”
Vermiculite
From the above it will be seen that using the normal anti-corrosion alone, a tenacious adhering deposit was formed, when the normal additive was combined with unexpanded vermiculite essentially the same results were obtained, but when expanded vermiculite was used the incubated mixture could be broken up easily.
In another series of experiments the results of which are shown in Table II, samples of the type described in connection with Table I were mixed thoroughly, with the results shown in the Table. Potentially hard crusts were formed without incubation even when unexpanded vermiculite was employed, but with expanded vermiculite there was no crust; instead the mixture remained totally fluid.
TABLE II
Sample
Results After 15 mins. Stirring
1.
MgO
A bottom hard crust.
2.
MgO + expanded
Totally dispersed-homogeneous
Vermiculite
(Source 1)
3.
MgO + expanded
Totally dispersed-homogeneous
Vermiculite
Source 2)
4.
MgO + micron
A bottom hard crust.
Vermiculite
(Source 1)
5.
MgO + micron
A bottom hard crust.
Vermiculite
(Source 2)
The relative proportions of bulking agents and normal additives may vary widely, from 10 parts of bulking agent per 90 parts of normal additive to 90 parts of bulking agent per 10 parts of normal additive.
The total amount of normal additives and bulking agents required is based on the flow rates of the flue-gas itself and the recirculating water solution from the scrubbers 20 , as well as the acidity existing in the system. Basically, the total amount to be used is determined primarily by the normal amount of usual additive that is required, but it is believed that using the bulking agent of the present invention in combination with the normal additive results in a diminution of the amount of normal additive usually required.
With a boiler of 200 megawatts, an SO 2 content of 6000 mg/Nm, and sulfuric acid content at the gas/gas heater of 10.5 mg/Nm 3 , and with a treatment rate with MgO of 40-100 Kg./Hr., the following results were obtained. The acidity with the use of MgO alone as in Table I was reduced to 5.0 mg/Nm 3 . Comparable results were obtained with lime (calcium hydroxide) at a treatment rate of 150-500 Kg./Hr., and in the case of limestone at 800-1500 Kg./Hr.
With the combination of the expanded vermiculite bulking agent, good results were obtained using only 15 Kg./Hr. of the MgO, and 5 Kg./Hr. of the bulking agent, a total of 20 Kg./Hr. for the combination, compared to 40 Kg./Hr. when using only the MgO, a reduction of 50% of the magnesium oxide, and with greatly improved cleanliness of the metal surface when both additives were used in combination.
In another example, with a treatment rate of 30 Kg./Hr. of a 25/75 blend of normal additive with an expanded vermiculite bulking agent there was a considerable reduction of the total amount of chemicals that were required, particularly when compared with the use of lime at 150 Kg./Hr., an 80% reduction, or with limestone at a rate of 800 Kg./Hr., a 96% reduction in additive rate. The extent of deposition build-up with the combination was in every case considerably less, and what build-up there was was much softer when compared to the singular use of any of the normal additives, such as lime, limestone, magnesia, or dolomite.
The most cost effective treatment rates may vary from boiler to boiler and will depend upon the megawatts of the boiler, the temperature at the inlet and outlet of the gas/gas heater, the acidity of the return flow rate from the scrubber to the gas/gas heater, the design of the gas/gas heater and the amount of sulfur dioxide and sulfuric acid present.
In actual practice, one can adjust the amounts of each additive and their relative ratios as has always been done by those versed in the art with additives generally.
The employment of the expanded substances as here described will be confirmed in and of itself, but it will also be effective when used with other additives, such as, for example, are disclosed in my earlier patents above identified.
I have called the additives of the present invention “bulking agents” because they appear to retain the bulk of the normal additives in the normal flow of materials through conduits and the system, but it may be that what those additives are doing is expanding the additives in the general flow of gas and liquids, so that the additives of the present invention might also be termed chemical expanding agents.
While a limited number of embodiments of the subject invention have been here specifically disclosed, and in particular while the use of the bulking agents has been described primarily in combination with certain specified basifying additives known to the prior art, and while the bulking agents here described appear to have particularly advantageous effects in combination with those conventional agents, it is believed that the bulking agents here described have significant value in and of themselves when used in analogous situations in flue-gas systems using other additives and even when used alone. It therefore will be apparent that many variations may be made in the details of the method here disclosed, all within the scope of the instant invention as defined in the following claims.
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A method for minimizing corrosion and the build-up of deposits on surfaces of a flue-gas system exposed to moist substances and elevated temperatures, and particularly those surfaces which are used to convey other additives to the system and the surfaces of gas/gas heaters which receive the output from scrubbers, which method involves adding to the system, particularly in those conduits and at the surfaces of the gas/gas heater, generally inert bulking agents such as perlite and vermiculite in expanded form, such agents, apparently by acting under the operating conditions to which they are subjected to retain substantial quantities of water without becoming dissolved, accomplishing the desired results.
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This application claims priority from German patent application serial no. 10 2012 212 370.9 filed Jul. 16, 2013.
FIELD OF THE INVENTION
The invention concerns a manual transmission for a motor vehicle.
BACKGROUND OF THE INVENTION
Manual transmissions of countershaft design and that can be actuated with manual shifting devices have long been in use in drive-trains of motor vehicles. In a conventional countershaft transmission loose wheels and fixed wheels, which mesh in pairs, are usually arranged in a number of gearset planes. In each case, the shifting of transmission gears is accomplished by opening a gear clutch of a gear that is engaged and closing a gear clutch of a target gear, whereby a rotationally fixed connection between a loose wheel and a gear shaft on which the loose wheel concerned is mounted to rotate is released, whereas another rotationally fixed connection between a loose wheel and a transmission shaft is formed. Before the formation of the force closure in the drive-train, the rotating components of the target gear that have to be engaged are synchronized. In order to save space and weight the gear clutches, i.e. the synchronizing devices or claw clutches of the shifting devices, are where possible formed as dual clutches such that two gear clutches or synchronizing devices at a time are arranged in shifting packets that can be actuated from both sides. The number of gears in such transmissions usually corresponds to the number of gearset planes.
To obtain more gears with a given number of gearset planes or, for a set number of gears, to produce a more compact and cost-saving structure with fewer gearset planes, it is already known to set up shifting logic systems in which, to produce the transmission gears, existing gearset planes and gear clutches are used more than one at a time. In such manual transmissions, due to the smaller number of components, to produce a force flow in the transmission when the gears are engaged in each case more than one gear clutch is closed or is kept closed.
The design of a manual shifting device for such a transmission is relatively complex, as shown for example by DE 10 2008 017 862 A1 from which an operating device for a 7-gear manual transmission with an H-type shifting pattern is known.
Thus, such transmissions are usually actuated by means of actuators which are controlled automatically by a control unit by virtue of a shifting program. But if such a compact manual transmission is to be operated by a driver as a manually shifted transmission with shift-lever actuation in a logical shift pattern, then in order to limit the design complexity it is appropriate to actuate at least part of the gearshift, i.e. in each case at least one of the gear clutches to be engaged for the gearshift, automatically with the help of an actuator.
When the shift lever is guided in the gearshift consoles of such a manual-shift device of an at least partially automated transmission, shift processes are initiated by actuator means and/or control elements of the transmission are operated manually. For this, gear clutches can be actuated both by shifting movements in the shifting gates of the gearshift console and also by selector movements in the selection gates of the gearshift console. This entails a correspondingly high level of complexity for the actuators and their control.
DE 10 2005 057 813 A1 describes a manual shift transmission with an input shaft, an output shaft arranged coaxially with and behind it, and a countershaft arranged with its axis parallel to these shafts. The transmission gears can be engaged in each case by closing more than one gear clutch. The transmission comprises five gearset planes for the production of six forward gears and one reverse gear, such that the fifth gear is designed as a direct gear and the sixth gear as an overdrive gear, i.e. a fast-driving gear. The third and fourth gearset planes consist in each case of two meshing loose wheels, the loose wheels on the countershaft side of the two gearset planes being firmly connected with one another. On the input shaft, the output shaft and the countershaft are arranged a total of seven gear clutches, arranged as three dual gear clutches and one single clutch. By suitable adaptation of the radial dimensions of the gear clutches, all the gear clutches can be mechanically actuated by way of a single shifting shaft or shifting roller.
DE 10 2010 043 564 A1 describes a manual shift transmission with a manual shifting device, which is designed as a group transmission. This transmission comprises an input shaft, an output shaft arranged coaxially with and behind it, and a countershaft arranged parallel to the shafts. With five gearset planes, six forward and one reverse gear can be obtained. The first two gearset planes act as a splitter group, wherein the second gearset plane is also active with the other gearset planes in a main group. Of the total of six gear clutches three are formed as dual clutches, and one of the dual clutches is connected to the input shaft while the other two dual clutches are connected to the output shaft. All the loose wheels are arranged on the input shaft and the output shaft, whereas all the fixed wheels are connected to the countershaft. The transmission can be shifted in an H-shifting pattern having a plurality of shifting gates and a selection gate orientated transversely thereto, such that when any gear is engaged, two of the gear clutches are in each case closed and in the shifting gates with two opposite gears in each case one of the gear clutches in the two gears is closed. Several of the gear clutches can be actuated both in the selection gates and also in one or more of the shifting gates. A comparable transmission is also known from DE 197 53 061 C1.
SUMMARY OF THE INVENTION
Against this background the purpose of the present invention is to introduce a compact manual transmission with which a comparatively large number of gears can be obtained, which can be actuated by means of a manual shifting device, which can be actuated in a manner that is simple in terms of both design and control technology, and which can be manufactured inexpensively.
The invention is based on the recognition that a manual transmission in which more than one gear clutch is engaged in each gear can be adapted to a manual shifting device, by designing a gearset with the gear clutches or synchronizers grouped into selection synchronizers and shifting synchronizers. This makes possible a shifting logic for shift actuation in a logical multiple-H shifting pattern in which some of the gear clutches, namely the selection synchronizers, need only a single actuator for automated shifting. For the remaining gear clutches, namely the shifting clutches, a relatively simple conventional manual or mechanical shifting device is sufficient.
Accordingly, the invention begins from a manual transmission of a motor vehicle, which can be actuated by means of a manual shifting device comprising a gearshift console with a selection gate in the form of a transverse slot and a number of shifting gates in the form of longitudinal slots for guiding a selector lever in a multiple-H shifting pattern, with an input shaft, with an output shaft arranged coaxially behind the input shaft and with a countershaft arranged axis-parallel to the two transmission shafts, wherein gearwheels are arranged in a number of gearset planes, the gearwheels being arranged as fixed wheels or loose wheels on the transmission shafts, respectively in a rotationally fixed manner or able to be connected rotationally fixed to the transmission shafts by means of gear clutches, such that the transmission gears can be engaged in each case by closing at least two of the gear clutches, and in which, in shifting gates having opposite gears, in each case one of the gear clutches in the two gears is engaged.
To achieve the stated objective the invention also provides that the gear clutches are divided into a selection group and a shifting group, such that the gear clutches of the selection group can be actuated exclusively by selection movements of the shift lever in the selection gates, whereby the input shaft can be coupled to the countershaft, and the gear clutches of the shifting group can be actuated exclusively by shifting movements of the shift lever in the shifting gates, whereby the output shaft can be coupled to the countershaft, and wherein the gear clutch engaged in the two respective gears in shifting gates having opposite gears is a gear clutch of the selection group.
In what follows, the gear clutches of the selection group are also referred to as selection synchronizers or simply as selection clutches, and the gear clutches of the shifting group are also referred to as shifting synchronizers or simply as shifting clutches. Preferably, all the gear clutches of the transmission are designed as synchronizing devices.
Furthermore, a dual clutch or dual synchronizer is understood to be a gear-shifting device in which two gear clutches or synchronizing devices are assembled in a shifting packet that can be actuated from both sides. A single clutch is correspondingly understood to be a single gear clutch or synchronizing device that can only be actuated from one side.
The functional grouping of the gear clutches enables a simple partial automation of a transmission that can be actuated in a multiple-H shifting pattern.
Thus, it can be provided that the gear clutches of the selection group can be engaged by shift lever movements actuated by external force and in an automated manner, so that just one controllable actuator is provided by means of which all the gear clutches of the selection group can be actuated.
Accordingly, only one actuator is needed for the automated part of the shift. The actuator is controlled for its actuation by an associated control unit, as soon as the latter detects by means of suitable sensors a selection movement of the shift lever for engaging the gear clutch concerned. A dual utilization of gear clutches by selection movements of the shift lever on the one hand and by shifting movements of the shift lever on the other hand, as is usual in known designs for compact transmissions, is avoided. This results in design and control-technological simplification of the operation of the transmission. The partially automated selection synchronization and manual shift synchronization of the transmission can thus be achieved relatively inexpensively.
A gearset of a transmission that conforms to the invention is designed such that those gear clutches which are or will be engaged in the gears by virtue of the selection movement of the shift lever, are not required in any of the shifting gates. Accordingly, to engage a gear, first of all a first gear clutch is engaged by a selection movement and then a second gear clutch is engaged in the appropriate shifting gate by means of the shifting movement. The gear clutch engaged in the shifting gate is correspondingly first opened when the gear is disengaged again. For a gearshift in a shifting gate into an opposite gear, there is no need for a repeated actuation of the gear clutch already previously engaged by the selection movement. For a gearshift in a shifting gate which ends in the selector gate, i.e. without an opposite gear or into another shifting gate, i.e. into a not-opposite gear, during the selection movement the appropriate gear clutches in the selector gate are automatically opened or engaged one after another, or they remain still engaged.
In this way the gear clutches of the selector group can be actuated by just one actuator in such manner that all the adjacent gearshifts can be carried out with the smallest possible number of shifting operations, and any conceivable gear intervals can be obtained.
In an embodiment of the invention, a gearset can be provided, in which six gearset planes for obtaining seven forward gears and at least one reverse gear are arranged, wherein all the loose wheels and all the gear clutches are arranged on the input shaft and the output shaft, wherein all the fixed wheels are arranged on the countershaft, wherein seven gear clutches are provided, which are in the form of three dual clutches and one single clutch, wherein one dual clutch and the single clutch form the selection group and are connected to the input shaft, whereas the other two dual clutches form the shifting group and are connected frictionally to the output shaft.
This gearset arrangement provides a 7-gear manually shifted transmission with a multiple-H shifting gate, which in a partially automated embodiment requires only one actuator for a selection synchronizer during the selection of the gears in the selection gate of the multiple-H shifting pattern. The gearset provides a 7-gear manually shifted transmission whose structure is more compact than a conventional 6-gear manual transmission. The arrangement of all the gear clutches on the input shaft and the output shaft gives the further advantage that loose component rattling, which can be produced by the drive engine due to non-uniform rotations in the transmission, is reduced.
In a shifting logic system of this 7-gear manually shifted transmission it can be provided that a first gear clutch of the selector group is associated with a first gear, a second gear and a first reverse gear, a second gear clutch of the selector group is associated with a third gear, a fourth gear and an optional second reverse gear, and a third gear clutch of the selector group is associated with a fifth gear, a sixth gear, a seventh gear and an optional third reverse gear.
This gives three groups of gears, each associated with just only the gear clutch of the selection group. The gear clutches of the shifting group, in contrast, are used more than once in two, or in all three gear groups. With this shifting logic the gear clutches of the selection group can be selected in such manner that they only have to be shifted if, starting from a middle shifting gate of a multiple-H shifting pattern, a selection movement to the right or to the left takes place. During the other selection movements, the engaged gear clutch of the selection group can remain engaged.
By virtue of this shifting logic, with which in the multiple-H shifting pattern a particular selection synchronizer is selected in a central position, any selection movement to the right of that position selects a particular second selection synchronizer and any selection movement to the left of that position selects a particular third selection synchronizer, so that one actuator is sufficient for controlling all three selection synchronizers provided in the embodiment of the gearset described.
Furthermore this enables the transmission to be operated with relatively few shifting operations, which increases the shifting comfort and reduces the shifting times.
The gradation or spread and the shifting logic of the transmission can be varied by exchanging individual gearset planes, in such manner, however, as to abide by the concept that during gear changes in the gear groups none of the selection synchronizers has to be shifted.
In particular it can be provided that a fifth gear can be engaged as a direct gear. The direct gear can be engaged by direct coupling of the input shaft to the output shaft by closing two of the gear clutches. The sixth and the seventh gears can then have overdrive gear ratios.
It is also possible that by closing the same two gear clutches, a fourth gear can be engaged as a direct gear, so that the fifth, sixth and seventh gears provide three overdrive gears. In this, the division into gear groups is retained.
Moreover it can be provided that the gear clutches of the shifting group can be shifted manually by the shifting movements. In that case, in comparison to a conventional manually shifted transmission, the shifting synchronizers can be controlled or engaged directly by the driver.
Basically, however, it is also possible for the gear clutches of the shifting group, i.e. the shifting synchronizers, to be engaged by the shift lever movements in an automated and auxiliary force actuated manner. Together with the automated control of the selection synchronizers this gives a manually shifted transmission that can be actuated by actuators in a completely automated manner. This also enables a connection of the manual shifting device to a so-termed shift-by-wire shifting system in which all shift lever movements are detected electronically and relayed to an electronic transmission control unit by way of signals transmitted via a data connection such as a data bus, the control unit then actuating the appropriate actuators. This entirely eliminates any need for a mechanical or hydraulic coupling of the manual shifting device to the transmission. Consequently the multiple-H shifting pattern, with which shifts of the individual gearshift devices are initiated in the selection gates and the shifting gates, can be produced comparatively simply and inexpensively with only one actuator for the selection synchronizers, as in the partially automated embodiment, and with a plurality of actuators for the shifting synchronizers.
BRIEF DESCRIPTION OF THE DRAWINGS
To clarify the invention further the description of a drawing illustrating an example embodiment is attached. The drawing shows:
FIG. 1 : A transmission according to the invention, shown in longitudinal section,
FIG. 2 : A schematic representation of the transmission shown in FIG. 1 ,
FIG. 3 : A shifting pattern for a manually shifted device applicable to the transmission represented schematically in FIG. 2 ,
FIG. 4 : A tabulated shifting scheme, arranged according to gears, associated with the shifting pattern of FIG. 3 ,
FIG. 5 : A tabulated shifting scheme, arranged according to gear groups with a fifth gear as direct gear, associated with the shifting pattern of FIG. 3 , and
FIG. 6 : A tabulated shifting scheme, arranged according to gear groups, with a fourth gear as direct gear.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A manual transmission 1 is designed as a countershaft transmission with an input shaft 2 on the drive input side, an output shaft 3 on the drive output side arranged coaxially with and behind the input shaft, and a countershaft 4 with its axis parallel to the transmission shafts 2 , 3 .
The six gearset planes a to f are in each case in the form of meshing spur gear pairs a 1 /a 2 , b 1 /b 2 , c 1 ,/c 2 , d 1 /d 2 , e 1 /e 2 and f 1 /f 2 , the last of these gearset planes f comprising in addition a rotatably mounted gearwheel f 3 for reversing the rotational direction in order to obtain reversing gears. The spur gear pairs a 1 /a 2 , b 1 /b 2 , c 1 ,/c 2 , d 1 /d 2 , e 1 /e 2 and f 1 /f 2 in each case comprise a loose wheel a 1 , b 1 , c 1 , d 1 , e 1 , f 1 , which is mounted to rotate on the input shaft 2 or the output shaft 3 and can be connected in a rotationally fixed manner to the shafts 2 , 3 by means of an associated gear clutch S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7 , as well as a fixed wheel a 2 , b 2 , c 2 , d 2 , e 2 , f 2 connected in a rotationally fixed manner to the countershaft 4 . The loose wheels a 1 , b 1 of the first two gearset planes a, b are arranged on the input shaft 2 whereas the loose wheels c 1 , d 1 , e 1 , f 1 of the rest of the gearset planes c, d, e, f are arranged on the output shaft 3 .
The seven gear clutches S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7 are designed as synchronizing devices and except for one gear clutch are assembled in each case into shifting packets that can be actuated from both sides. A first shifting packet S 1 /S 2 on the input side is connected to the input shaft 2 and is arranged between the first and second gearset planes a, b. By means of this first dual synchronizer S 1 /S 2 , a rotationally fixed connection can be formed selectively between the loose wheel a 1 of the first gearset plane a or the loose wheel b 1 of the second gearset plane b and the input shaft 2 .
Furthermore the gear clutch S 3 is designed as a single synchronizing device and is connected rotationally fixed to the end of the input shaft 2 remote from the drive input. By means of this gear clutch S 3 , a rotationally fixed connection can be formed between the input shaft 2 and the adjacent loose wheel c 1 of the third gearset plane c. In addition the loose wheel c 1 can be connected rotationally fixed to the output shaft 3 by means of the adjacent gear clutch S 4 of the second dual synchronizer S 4 /S 5 . Thus, the loose wheel c 1 is the only loose wheel that has two gear clutches S 3 , S 4 associated with it. By closing the two gear clutches S 3 , S 4 a direct connection can be formed between the input shaft 2 and the output shaft 3 , i.e. between the transmission input and the transmission output. The second and third gear clutches S 4 /S 5 and S 6 /S 7 formed in each case as dual synchronizers, selectively connect the other loose wheels c 1 or d 1 and e 1 or f 1 to the output shaft 3 .
Thus the first three spur gear stages a, b, c can be coupled to the input shaft 2 by the first three gear clutches or synchronizers S 1 /S 2 , S 3 , and the third and fourth spur gear stages c, d and the fifth and sixth spur gear stages e, f by the fourth to the seventh gear clutches or synchronizers S 4 /S 5 and S 6 /S 7 .
The transmission 1 shown in FIGS. 1 and 2 provides seven forward gears 1 G, 2 G, 3 G, 4 G, 5 G, 6 G, 7 G and up to three reverse gears R 1 , R 2 , R 3 . The force flow in the individual gears is indicated by a force-flow diagram shown in FIG. 2 under the transmission layout. The force flow lines are associated at their jump-points with the respective gearsets that are transmitting torque.
The shifting scheme for this transmission 1 can be seen in the table shown as FIG. 4 . According to this, in each gear two of the gear clutches S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7 are engaged, while a fifth gear 5 G can be engaged as a direct gear. The two gears 6 G, 7 G higher than that are provided as overdrive gears.
The shifting scheme in FIG. 4 can be applied with a manual shifting device for this transmission 1 , which is illustrated in FIG. 3 . According to this, to operate the transmission 1 in a multiple-H shifting pattern 5 a gearshift console gate 6 with a shift lever (not shown) that can be guided therein is provided, having five shifting gates 8 a , 8 b , 8 c , 8 d and 8 e connected to one another by a selection gate 7 arranged perpendicularly thereto. The first shifting gate 8 a is intended for a reverse gear R 1 and the last shifting gate 8 e for the highest, namely the seventh gear 7 G. Between these are arranged three more shifting gates 8 b , 8 c , 8 d , in which in each case two gears 1 G/ 2 G, 3 G/ 4 G, 5 G/ 6 G are positioned in a logical arrangement and in increasing sequence opposite one another.
The operation of the transmission by means of this manual shifting device takes place in two functional steps, a selection synchronization and a shifting synchronization.
For the selection synchronization the input shaft 2 is coupled to the countershaft 4 during a selection movement of the shift lever. The first three synchronizers S 1 , S 2 , S 3 shown in FIG. 2 act as selection synchronizers. These are chosen such that they only have to be shifted when they are selected by moving to the right or left out of the middle shifting gate 8 c , in which the third and fourth gears G 3 , G 4 can be engaged. When changing gates between the first two shifting gates 8 a , 8 b , i.e. between the first two gears 1 G, 2 G and the reverse gear, and also when changing gates between the last two shifting gates 8 d and 9 e , i.e. between the fifth, sixth and seventh gears 5 G, 6 G, 7 G, no actuation of the respective selection synchronizers S 1 , S 3 is necessary. Likewise, no actuation of the selection synchronizer S 2 is needed when changing gear in the middle gate 8 c , i.e. between the third gear 3 G and the fourth gear 4 G.
Thus, there are three gear groups and each of these is associated with one selection synchronizer S 1 , S 2 , S 3 . These associations are indicated in the table constituting FIG. 5 , from which it can be seen that within the gear groups the selection synchronizers S 1 , S 2 , S 3 are in each case predetermined, whereas the shifting synchronizers S 4 , S 5 , S 6 corresponding to the gears vary. The seventh synchronizer S 7 is used for the reverse gear R. The possible additional reverse gears R 2 , R 3 are not taken into account in the shifting pattern 5 shown in FIG. 3 .
Consequently, all three selection synchronizers S 1 , S 2 and S 3 can be controlled with only one actuator. Correspondingly, for this part of the gearshift an actuator (not shown) is provided for automatic actuation of the appropriate shifting elements, which is controlled in accordance with the respective selection movements of the shift lever.
For the shifting synchronization that follows the selection synchronization, the output shaft 3 is coupled to the already synchronized unit comprising the countershaft 4 and the input shaft 2 during the shifting movement of the shift lever. The other synchronizers S 4 , S 5 , S 6 and S 7 , which do not act as selection synchronizers, are provided as shifting synchronizers. The shifting synchronizers S 4 , S 5 , S 6 , S 7 are actuated manually by the driver. Thus, the transmission 1 works as a partially automated manual shift transmission.
It should be mentioned that alternatively to the shifting scheme shown in FIGS. 2 to 5 , in which a fifth gear 5 G can be engaged as a direct gear, a shifting scheme with a fourth gear 4 G as the direct gear 4 D is possible. This is only indicated in the table forming FIG. 6 , wherein three gear groups are again provided, each of them associated with a respective selection synchronizer S 1 , S 2 , S 3 , so that in the groups no selection synchronizer has to be shifted.
Accordingly, analogously to the first example embodiment, the third and fourth synchronizers S 3 , S 4 produce the direct gear 4 D. The selection synchronizer for a first gear group 1 G, 2 G, R can be the first or second synchronizer S 1 or S 2 , while the selection synchronizer for a third gear group 5 G, 6 G. 7 G can be the other of the first two synchronizers S 1 , S 2 . The shifting synchronizers S 4 , S 5 , S 6 , S 7 can each be associated with these gear groups.
LIST OF INDEXES
1 Transmission
2 Input shaft
3 Output shaft
4 Countershaft
5 Shifting pattern
6 Gearshift console
7 Selection gate
8 a Shifting gate
8 b Shifting gate
8 c Shifting gate
8 d Shifting gate
8 e Shifting gate
a Gearset plane
b Gearset plane
c Gearset plane
d Gearset plane
e Gearset plane
f Gearset plane
a 1 Loose wheel
b 1 Loose wheel
c 1 Loose wheel
d 1 Loose wheel
e 1 Loose wheel
f 1 Loose wheel
a 2 Fixed wheel
b 2 Fixed wheel
c 2 Fixed wheel
d 2 Fixed wheel
e 2 Fixed wheel
f 2 Fixed wheel
f 3 Wheel for reversing the rotational direction
S 1 Gear clutch, selection synchronizer
S 2 Gear clutch, selection synchronizer
S 3 Gear clutch, selection synchronizer
S 4 Gear clutch, shifting synchronizer
S 5 Gear clutch, shifting synchronizer
S 6 Gear clutch, shifting synchronizer
S 7 Gear clutch, shifting synchronizer
1 G First gear
2 G Second gear
3 G Third gear
4 G Fourth gear
5 G Fifth gear
6 G Sixth gear
7 G Seventh gear
R 1 First reverse gear
R 2 Second reverse gear
R 3 Third reverse gear
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A manual transmission of a motor vehicle, is actuated by manually shifting a shift lever in a gearshift console having a selector gate and shifting gates in a multiple-H shifting pattern, with coaxial input and output shafts and a parallel countershaft, and with a number of gearset planes. Transmission gears are implemented by engaging at least two associated gear clutches. The gear clutches are divided into a selection group and a shifting group. The selection group gear clutches can be actuated exclusively by moving the shift lever in the selection gate so as to couple the input and counter-shafts. The shifting group gear clutches can be actuated exclusively by moving the shift lever in the shifting gates so as to couple the output and counter-shafts, and the gear clutch respectively engaged in the shifting gates having the two opposite gears is a selection group gear clutch.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority of French Application No. 02 12586 filed Oct. 10, 2002 and United States Provisional Application No. 60/477,008 filed Feb. 13, 2003, the teachings of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an applicator for applying a substance, for example, nail varnish, to nails.
BACKGROUND OF THE INVENTION
[0003] A nail varnish applicator is known from European patent EP 0 651 955, comprising a rod, and bristles fixed in a housing of the rod, the housing being of oblong cross-section. In the examples shown in that patent, the opening of the housing has in cross-section a contour that matches the contour of the rod in the shape of a kidney or with two main sides slightly concave outwardly, such that the thickness of the wall surrounding the housing is constant.
[0004] A nail varnish applicator is also known from JP-4-28812, having a rod that includes a plurality of longitudinal grooves distributed in substantially uniform manner over its entire periphery.
SUMMARY OF THE INVENTION
[0005] A need exists to facilitate applying a substance such as nail varnish and to enable it to be spread more precisely. The Applicant has observed that with known applicators, the substance which flows along the rod and reaches the sides of the brush is relatively difficult to spread with precision.
[0006] According to one or more embodiments of the present invention, an applicator comprises a rod and bristles fixed in a housing of an end portion of the rod, the housing having an opening of oblong cross-section with a long axis X, and the rod having a wall of varying thickness around the housing.
[0007] In one aspect of the invention, in the end portion of the applicator including the housing that receives the bristles of the brush, the rod has a cross-section having an outer contour that is not concave, with the exception of one or more grooves situated opposite each other. The groove(s) extend along at least a portion of the rod and are situated substantially mid-way along the long axis X of the housing when the rod is observed in cross-section. According to certain embodiments, the outer contour of the rod may be convex and, where appropriate, it may include at least one flat side.
[0008] In one of more embodiments of the invention, the thickness or depth around the rod of the substance for application is greater in the groove(s) than on the sides. According to these embodiments, the substance which flows along the rod when the applicator is removed from the receptacle thus reaches the bundle of bristles preferentially in a substantially central region of said bundle, so that the substance can be spread under good conditions. The quantity of substance reaching the sides of the brush is small.
[0009] As mentioned above, the rod may include a second groove, opposite the first, and the applicator may be symmetrical about a mid plane. The two grooves can thus be symmetrical about a mid-plane parallel to the long axis X, but within the scope of the present invention for the grooves to be of different shapes.
[0010] In certain embodiments, the opening of the housing may advantageously have a cross-section that is substantially rectangular, thereby enabling a substantially uniform distribution of substance on the bristles to be obtained, but other shapes are within the scope of the present invention, for example, an oval cross-section.
[0011] According to one or more embodiments, in cross-section, the end portion of the rod may have two opposite sides that are outwardly convex, for example, in the shape of circular arcs, each connecting one of the sides including a groove to the opposite side. In cross-section, the or each groove may have a contour in the shape of a circular arc, for example.
[0012] In other embodiments, the housing may have a cross-section that tapers progressively towards its end wall, said taper matching the divergence desired for the bristles. The end wall of the housing may include a recess in which the bristles are fixed, and which opens out into a portion of the housing which flares out towards the opening of the housing, the portion enabling the bristles to splay apart from one another so as to impart a wider shape to the brush.
[0013] In certain embodiments, the housing may be arranged so that the bristles extend outside the housing over a width, measured parallel to the long axis X, that is greater than the width of the rod at the housing. A relatively wide brush is thus obtained.
[0014] According to some embodiments, the length of the portion of the bristles which projects from the housing of the rod can lie in the range of about 5 millimeters (mm) to about 20 mm, for example. In certain embodiments, the free ends of the bristles may substantially describe an arc of a circle, having a radius of curvature lying in the range of about 2 mm to about 15 mm, for example, and in particular in the range of about 4 mm to about 10 mm. According to certain embodiments, the width of the opening of the housing, measured perpendicularly to the long axis X, may be no greater than about 2 mm.
[0015] Close to the longitudinal ends along the long axis X of the housing, the walls of the rod may be relatively thin. Thus, in an embodiment of the invention, the rod may have wall thickness around the housing that is smaller when measured at a longitudinal end of the housing than when measured mid-way along the housing.
[0016] Still in a particular embodiment, the thickness of the wall extending around the housing passes through a minimum in the portions that are adjacent to the longitudinal ends of the long axis of the housing. In another particular embodiment, at its widest point, the portion of the rod that is immersed in the substance contained in the receptacle when the applicator is in place on said receptacle may be no greater than to 5 mm. In certain embodiments, the rod may be arranged so as to be fixed to a closure cap of the receptacle; in a variant, the rod may be made in a single integral piece with a closure cap of the receptacle, by molding plastics material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention will be better understood on reading the following detailed description of non-limiting embodiments thereof, and on examining the accompanying drawings, in which:
[0018] [0018]FIG. 1 is a side, elevational, cross-sectional view of a device in accordance with one embodiment of the present invention for applying a substance to the nails;
[0019] [0019]FIG. 2 is a side, elevational, cross-sectional fragmentary view of the applicator shown in the device of FIG. 1;
[0020] [0020]FIG. 3 is a side, elevational, cross-sectional view of the rod of the applicator shown in FIG. 1;
[0021] [0021]FIG. 4 shows a detail of the housing receiving the bristles of the brush;
[0022] [0022]FIG. 5 is a side, elevational, cross-sectional partial view taken along section V-V in FIG. 4;
[0023] [0023]FIG. 6 is a sectional view on V-V of variant embodiment of the end portion of the rod;
[0024] [0024]FIG. 7 is a sectional view on V-V of variant embodiment of the end portion of the rod;
[0025] [0025]FIG. 8 is a sectional view on V-V of variant embodiment of the end portion of the rod;
[0026] [0026]FIG. 9 is a sectional view on V-V of variant embodiment of the end portion of the rod;
[0027] [0027]FIG. 10 is a sectional view on V-V of variant embodiment of the end portion of the rod;
[0028] [0028]FIG. 11 is a sectional view on V-V of variant embodiment of the end portion of the rod;
[0029] [0029]FIG. 12 is a sectional view on V-V of a variant embodiment of the end portion of the rod;
[0030] [0030]FIG. 13 shows a variant configuration of the housing, showing a different distribution of the bristles outside the rod;
[0031] [0031]FIG. 14 shows a variant configuration of the housing, showing a different distribution of the bristles outside the rod;
[0032] [0032]FIG. 15 shows, in isolation, an end portion of the bristles of the brush; and
[0033] [0033]FIG. 16 is a fragmentary longitudinal section of the rod made integrally with a cap.
DETAILED DESCRIPTION
[0034] Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or carried out in various ways.
[0035] [0035]FIG. 1 shows an exemplary embodiment of a device 1 for applying a substance to the nails, for example, a nail varnish V, the device comprising a receptacle 2 containing the varnish V, and an applicator 3 comprising a rod 4 made of plastics material, provided at one end with a flat brush 5 , and at the other end with a handle member 10 also constituting a closure cap of the receptacle 2 . In the embodiment shown in FIG. 1, the receptacle 2 also contains a bead 6 , e.g. a metal ball-bearing, enabling the varnish V to be homogenized before application, by shaking the device 1 .
[0036] In FIGS. 1 to 3 , it can be seen that the top end of the rod 4 has a skirt 8 enabling it to be fixed in a housing of the cap 10 , said cap being configured so as to be screwed onto the neck 11 of the receptacle 2 . A collar 12 is formed at the base of the skirt 8 so as to bear against the top edge of the neck 11 when the applicator is in place on the receptacle 2 .
[0037] Beneath the collar 12 , the rod 4 includes a cone-shaped portion 13 suitable for contributing to sealing the closure of the receptacle 2 when the applicator 3 is in place on said receptacle. Sealing could also be obtained through cooperation between the surface of the cap 10 and of the neck of the receptacle. The rod 4 also includes a bottom end portion 14 which is provided with a housing 15 inside which the bristles of the brush 5 are held, e.g. by stapling, gluing, heat sealing, or overmolding.
[0038] As can be seen in FIG. 4, the free end of the rod 4 may be beveled at 20 . In the example shown, the rod 4 includes two opposite longitudinal grooves 18 extending along a major fraction of its length up to its distal end 17 . In the embodiment shown, the housing 15 has an opening of rectangular cross-section of elongate shape with a long axis X perpendicular to the longitudinal axis of the rod 4 . In the embodiment under consideration, the outside contour of the rod 4 and the housing 15 are symmetrical about the axis X and about a mid-axis Y perpendicular to the axis X.
[0039] It can be seen in FIG. 5 that the wall thickness of the material surrounding the housing 15 is not constant. Apart from the grooves 18 , the outside contour 16 of the rod 4 is convex, when said rod is observed in cross-section. More particularly, in the embodiment under consideration, the contour of the rod 4 is defined in the grooves 18 by circular portions 16 a , the portions 16 a being united at their ends by circular portions 16 b that are outwardly convex and that are of smaller radius of curvature than the portions 16 a.
[0040] As can be seen in FIG. 4, the housing 15 can have a cross-section which tapers towards the end wall 19 of the housing. The bristles of the brush 5 splay apart when the brush is applied to a nail. Depending on the shape of the housing 15 , a narrower or wider bundle of bristles can be obtained, as shown in FIGS. 13 and 14.
[0041] It can be seen in FIG. 13 that by providing a housing 15 with a substantially constant cross-section, a brush is obtained having bristles that are relatively close together, whereas by providing the housing 15 with an outwardly flaring shape, the bristles are able to splay further apart from one another so as to form a relatively wide bundle.
[0042] In its end wall, the housing 15 can be made with a recess 15 a in which the bristles are secured to the rod. The recess 15 a can open out into a portion 15 b which flares out towards the open end of the housing 15 , enabling the bristles to splay apart from one another.
[0043] As can be seen in FIG. 14, the housing 15 can thus be made in such a manner that the maximum transverse dimension l 2 of the brush, measured parallel to the long axis X, is greater than the transverse dimension l 1 of the rod at the housing 15 .
[0044] As can be seen in FIG. 15, the free ends of the bristles of the brush 5 can be situated along a substantially circular curve C, for example. In a variant, the free ends of the bristles could be situated substantially along a straight line, for example. The length e of the portion of the bristles which projects from the housing 15 lies in the range of about 5 mm to 20 mm, for example.
[0045] The device 1 can be used as follows. The user shakes the receptacle 2 so as to enable the bead to homogenize the varnish V, and then the user unscrews the cap 10 and uses the brush 5 to apply the varnish.
[0046] When the applicator 3 is removed from the receptacle 2 , substance is present on the rod 4 and said substance flows by gravity towards the brush 5 . The thickness or depth of substance is greater in the grooves 18 , which can retain more substance by capillarity. The substance preferably flows into the central region of the brush, thereby enabling it to be spread more easily and more precisely.
[0047] It will be understood of course that the invention is not limited to the embodiment described above. In particular, it is possible to modify the shape of the housing and/or the shape of the end portion of the rod in which said housing is made. By way of example, FIGS. 6 to 12 show various, non limited examples of possible shapes of housing, from among other possible shapes.
[0048] It can be seen in FIG. 6 that the rod can include a single groove 18 only. It can be seen in FIG. 7 that the opening of the housing can have a cross-section that is not rectangular but oblong, e.g. elliptical. It can be seen in FIG. 8 that the opening of the housing can have a cross-section having two slight concavities 15 c in its long sides, the two concavities being less pronounced, however, than the concavities formed by the grooves 18 .
[0049] It can be seen in FIG. 9 that the grooves 18 can be relatively narrow, so as to increase further the retention of substance by capillarity, for example. It can be seen in FIG. 10 that the grooves 18 can have a triangular profile in cross-section. FIG. 11 illustrates the fact that the wall thickness e 1 in the vicinity of the longitudinal ends of the housing 15 can be smaller than the wall thickness e 2 substantially mid-way along the housing 15 . If necessary, the thickness e 1 can correspond to a minimum. A small thickness e 1 enables a housing 15 to be made to be longer along the long axis X, thereby enabling a brush to be obtained that is very wide or that is capable of widening easily. FIG. 12 shows the possibility of having two grooves 18 of different shapes. The rod 4 can also be made in a single integral piece with the closure cap of the receptacle, as shown in FIG. 16.
[0050] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents.
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An applicator for applying a substance to nails is disclosed. The applicator comprises a rod having an end portion, the end portion having a housing, the housing having an opening of oblong cross-section with a long axis, the rod having a wall of varying thickness around the housing. In the end portion, the rod has a cross-section having an outer contour that is not concave, with the exception of one or more grooves situated opposite each other.
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[0001] This application claims benefit from prior Provisional Application Serial No. 60/135,290, filed May 21, 1999.
TECHNICAL FIELD
[0002] This invention relates to an apparatus and method for the construction and utilization of molecular deposition domains. More specifically, this invention is a method for the construction and utilization of molecular deposition domains into a high density molecular array for identifying and characterizing molecular interaction events.
BACKGROUND
[0003] Interactions between molecules is a central theme in living systems. These interactions are key to myriad biochemical and signal transduction pathways. Messages from outside a cell travel along signal transduction pathways into the cell's nucleus, where they trigger key cellular functions. Such pathways in turn dictate the status of the overall system. Slight changes or abnormalities in the interactions between biomolecules can effect the biochemical and signal transduction pathways, resulting in inappropriate development, cancer, a variety of disease states, and even cell senescence and death. On the other hand, it can be extremely beneficial to develop reagents and effectors that can inhibit, stimulate, or otherwise effect specific types of molecular interactions in biochemical systems; including biochemical and signal transduction pathways. Reagents and effectors that effect nucleus interactions may often become very powerful drugs which can be used to treat a variety of conditions.
[0004] Current Technology
[0005] Several recent studies have shown that a scanning probe microscope “SPM” may be used to study molecular interactions by making a number of measurements. The SPM measurements may include changes in height, friction, phase, frequency, amplitude, and elasticity. The SPM probe can even perform direct measurements of the forces present between molecules situated on the SPM probe and molecules immobilized on a surface. For example, see Lee, G. U., L. A. Chrisey, and R. J. Colton, Direct Measurement of the Forces Between Complementary Strands of DNA. Science, 1994. 266: p. 771-773; Hinterdorfer, P., W. Baumgartner, H. J. Gruber, and H. Schindler, Detection and Localization of Individual Antibody - antigen Recognition Events by Atomic Force Microscopy, Proc. Natl. Acad. Sci., 1996. 93: p. 3477-3481; Darnmer, U., O. Popescu, P. Wagner, D. Anselmetti, H. -J. Guntherodt, and G. N. Misevic, Binding Strength Between Cell Adhesion Poteoglycans Measured by Atomic Force Microscopy. Science, 1995. 267: p. 1173-1175; Jones, v. et al. Microminiaturized Immunoassays Using Atomic Force Microscopy and Compositionally Patterned Antigen Arrays, Analy. Chem., 1998 70(7): p. 1233-1241; and Rief, M., F. Oesterhelt, B. Heymann, and H. E. Gaub, Single Molecule Force Spectroscopy on Polysaccharides by Atomic Force Microscopy, Science, 1997. 275: p. 1295-1297. The above studies illustrate that it is possible to readily and directly measure the interaction between and within virtually all types of molecules by utilizing an SPM. Furthermore, recent studies have shown that it is possible to use direct force measurement to detect changes in molecular complex formation caused by the addition of a soluble molecular species. A direct force measurement may elucidate the effect of soluble molecular species on the interaction between a molecular species on an SPM probe and a surface.
[0006] Molecular Arrays
[0007] The ability to measure molecular events in patterned arrays is an emerging technology. The deposition material can be deposited on a solitary spot or in a variety of sizes and patterns on the surface. The arrays can be used to discover new compounds which may interact in a characterizable way with the deposited material. Arrays provide a large number of different test sites in a relatively small area. To form an array, one must be able to define a particular site at which a deposition sample can be placed in a defined and reproducible manner.
[0008] There are four approaches for building conventional molecular arrays known in the art. These prior art methods include 1) mechanical deposition, 2) in situ photochemical synthesis, 3) “ink jet” printing, and 4) electronically driven deposition. The size of the deposition spot (or “domain”) is of particular importance when utilizing an SPM to scan for molecular recognition events. Current SPM technology only allows a scan in a defined area. Placing more domains in this defined area allows for a wider variety of molecular interaction events to be simultaneously tested.
[0009] Mechanical deposition is commonly carried out using a “pin tool” device. Typically the pin tool is a metal or similar cylindrical shaft that may be split at the end to facilitate capillary take up of liquid. Typically the pin is dipped in the source and moved to the deposition location and touched to the surface to transfer material to that domain. In one design the pin tool is loaded by passing through a circular ring that contains a film of the desired sample held in the ring by surface tension. The pin tool is washed and this process repeated. Currently, pin tool approaches are limited to spot sizes of 25 to 100 microns or larger. The spot size puts a constraint on the maximum density for the molecular deposition sites constructed in this manner. A need exists for a method that allows for molecular domains of smaller dimensions to be deposited.
[0010] In situ photochemical procedures allow for the construction of arrays of molecular species at spatial addresses in the 1-10 micron size range and larger. In situ photochemical construction can be carried out by shining a light through a mask. Photochemical synthesis occurs only at those locations receiving the light. By changing the mask at each step, a variety of chemical reactions at specific addresses can be carried out. The photochemical approach is usually used for the synthesis of a nucleic acid or a peptide array. A significant limitation of this approach is that the size of the synthetic products is constrained by the coupling efficiency at each step. Practically, this results in appreciable synthesis of only a relatively short peptide and nucleic acid specimen. In addition, it becomes increasingly improbable that a molecule will fold into a biologically relevant higher order architecture as the synthetic species becomes larger. A need exists for an alternative method for deposition of macromolecular species that will preserve the molecular formation of interest in addition to avoiding the cost of constructing the multiple masks used in this method.
[0011] Ink jet printing is an alternative method for constructing a molecular array. Ink jet printing of molecular species produces spots in the 100 micron range. This approach is only useful for printing a relatively small number of species because of the need for extensive cleaning between printing events. A key issue with ink jet printing is maintenance of the structural/functional integrity of the sample being printed. The ejection rate of the material from the printer results in shear forces that may significantly compromise sample integrity. A need exists for a method that will retain the initial structure and functional aspects of the deposition material and that will form smaller spots than are possible with the above ink jet method.
[0012] Electronic deposition is yet another method known for the construction of molecular arrays. Electronic deposition may be accomplished by the independent charging of conductive pads, causing local electrochemical events which lead to the sample deposition. This approach has been used for deposition of DNA samples by drawing the DNA to specific addresses and holding them in a capture matrix above the address. The electronic nature of the address can be used to manipulate samples at that location, for example, to locally denature DNA samples. A disadvantage of this approach is that the address density and size is limited by the dimensions of the electronic array.
[0013] A need exists for a molecular deposition technique that will allow for smaller deposition spots (domains). Smaller deposition domains allow for an array to be constructed with a greater density of domains. More domains further allow for a wider variety in the deposition material to be placed on the same array, allowing a user to search for more molecular interaction events simultaneously.
[0014] A further need exists for the ability to place these spots at a defined spatial address. Placing the domains at defined spatial addresses allows the user to know exactly what deposition material the SPM is scanning at any given time.
[0015] Furthermore, a need exists for a method to make deposition domains with large molecular weight samples that also retains the desired chemical formation. Finally, a need exists for the efficient construction of these molecule domains into an array.
[0016] Molecular Detection
[0017] All of the above examples are further limited because they require some type of labeling of the deposition sample for testing. Typical labeling schemes may include fluorescent or other tags coupled to a probe molecule. In a typical molecular event experiment, an array of known samples, for example DNA sequences, will be incubated with a solution containing a fluorescent indicator. In the DNA example this would be fluorescently or otherwise labeled nucleic acids, most often a single stranded DNA of an unknown sequence. Specific sequence elements are identified in the DNA sample by virtue of the hybridization of the label to addresses containing known sequence elements. This process has been used to screen entire ensembles of expressed genes in a given population of cells at a particular time or under a particular set of conditions. Other labeling procedures have also been employed, including RF (radio frequency) labels and magnetic labels. These methods are less frequently used, however, than the fluorescent label methods desired above. All of these labels hinder experiments with extra steps, reagents, and in some cases, risk.
[0018] Other methods for the detection of the interactions of molecules on a molecular array include inverse cyclic voltametry, capacitance or other electronic changes, radioactivity (such as with isotopes of phosphorous), and chemical reactions. In virtually all cases, some form of labeling of the probe molecule that is added to the array is required. This is a significant limitation of current arrays. A need exists for a method that does not require this extra labeling step.
[0019] Scanning Probe Microscopy
[0020] A wide variety of SPM instruments are capable of detecting optical, electronic, conductive, and other properties. One form of SPM, the atomic force microscope (AFM), is an ultra-sensitive force transduction system. In the AFM, a sharp tip is situated at the end of a flexible cantilever and scanned over a sample surface. While scanning, the cantilever is deflected by the net sum of the attractive and repulsive forces between the tip and sample. If the spring constant of the cantilever is known, the net interaction force can be accurately determined from the deflection of the cantilever. The deflection of the cantilever is usually measured by the reflection of a focused laser beam from the back of the cantilever onto a split photodiode, constituting an “optical lever” or “beam deflection” mechanism. Other methods for the detection of cantilever deflection include interferometry and piezoelectric strain gauges.
[0021] The first AFMs recorded only the vertical displacements of the cantilever. More recent methods involve resonating the tip and allowing only transient contact, or in some cases no contact at all, between it and the sample. Plots of tip displacement or resonance changes as it traverses a sample surface are used to generate topographic images. Such images have revealed the three dimensional structure of a wide variety of sample types including material, chemical, and biological specimens. Some examples of the latter include DNA, proteins, chromatin, chromosomes, ion channels, and even living cells.
[0022] In addition to its imaging capabilities, the AFM can make extremely fine force measurements. The AFM can directly sense and measure forces in the microNetwon (10 −6 ) to picoNewton (10 −12 ) range. Thus, the AFM can measure forces between molecular pairs, and even within single molecules. Moreover, the AFM can measure a wide variety of other forces and phenomena, such as magnetic fields, thermal gradients and viscoelasticity. This ability can be exploited to map force fields on a sample surface, and reveal with high resolution the location and magnitude of these fields, as in, for example, localizing complexes of interest located on a specific surface.
[0023] Direct Force Measurement
[0024] To make molecular force measurements, the AFM probe is functionalized with a molecule of interest. This bio- or chemi-active probe is then scanned across the surface of interest. The molecule tethered to the probe interacts with the corresponding molecule or atoms of interest on the surface being studied. The interactions between the molecule functionalized on the probe and the molecules or atoms on the surface create minute forces that can be measured by displacement of the probe. The measurement is typically displayed as a force vs. distance curve (“force curve”).
[0025] To generate a force curve, the tip or sample is cycled through motions of vertical extension and retraction. Each cycle brings the tip into contact with the sample, then pulls the tip out of contact. The displacement of the cantilever is zero until the extension motion brings the tip into contact with the surface. Then the tip and sample are physically coupled as the extension continues. The physical coupling is the result of hard surface contact (Van der Waals interactions) between the probe and the surface. This interaction continues for the duration of the extension component of the cycle. When the cycle is reversed and the tip retracted, the physical contact is broken. If there is no attractive interaction between the tip and sample the tip separates from the sample at the same position in space at which they made contact during extension. However, if there is an adhesive interaction between the tip and sample during retraction, the cantilever will bend past its resting position and continue to bend until the restoring force of the cantilever is sufficient to rupture the adhesive force.
[0026] In the case of extendable molecular interactions, the distance between the tip and surface at which a rupture is observed corresponds to the extension length of the molecular complex. This information can be used to measure molecular lengths and to measure internal rupture forces within single molecules. In a force curve an adhesive interaction is represented by an “adhesion spike.” Since the spring constant of the probe is known, the adhesive force (the unbinding force) can be precisely determined. Upon careful inspection of a typical adhesion spike, many small quantal unbinding events are frequently seen. The smallest unbinding event that can be evenly divided into the larger events can be interpreted as representing the unbinding force for a single molecular pair.
[0027] The spectra produced by these binding events will contain information about the coupling contacts holding the molecules together. Thus, it is possible to interpret the signature generated by a mechanical denaturation experiment with regard to the internal structure of the molecule. An SPM can further utilize height, friction, and elasticity measurements to detect molecular recognition events. Molecular recognition events are when one molecule interacts with another molecule or atom in, for example, an ionic bond, a hydrophobic bond, electrostatic bond, a bridge through a third molecule such as water, or a combination of these methods.
[0028] In an alternative approach, the AFM probe is oscillated at or near its resonance frequency to enable the measurement of recognizance parameters, including amplitude, frequency and phase. Changes in the amplitude, phase, and frequency parameters are extremely sensitive to variations in the interaction between the probe and the surface. If the local elasticity or viscosity of the surface changes as a result of a molecular recognition event, there is a shift in one or more of these parameters.
[0029] Others have reported using AFMs and STMs for the deposition of materials. One report is from Chad Mirkin (Northwestern University) in which he used an AFM to write nanometer scale molecule features with short alkane chains. Hong, S., J. Zhu, and C. A. Mirkin, Multiple Ink Nanolithography: Toward A Multiple - Pen Nano - Plotter, Science. 1999, p. 523-525. A need exists, however, for a molecular domain deposition method that is not limited to short chain length molecules. A need exists for a method for depositing longer chain length macromolecules that does not change or hinder the formation of the deposited molecule.
[0030] A need exists for an improved apparatus and method for utilization in the detection of molecular interaction events. A need exists for a method for the creation of small, sub-micron scale molecular domains at defined spatial addresses. This apparatus should enable the user to test for a variety of different types of events in a spatially and materially efficient manner by facilitating the deposition, exposure, and scanning of molecular domains to detect a resultant molecular interaction event. Furthermore, an apparatus is needed that enables the placement of a large number of molecular domains in a relatively small area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] [0031]FIG. 1 is a block diagram of the method of forming a deposition domain.
[0032] [0032]FIG. 2 is a block diagram of the method of forming an array and utilizing the same.
[0033] [0033]FIG. 3 is a side view of the deposition device used with the present invention.
[0034] [0034]FIG. 4 is a side view of the deposition device and the microspheres of the present invention.
[0035] [0035]FIG. 5 is a side view of a microsphere attached to a deposition device.
[0036] [0036]FIG. 6 is an alternative attachment of the microsphere to the deposition device.
[0037] [0037]FIG. 7 a is a side view of the deposition device before loading the deposition material on it.
[0038] [0038]FIG. 7 b is a side view of a capillary bridge between the deposition material and the microsphere during loading of the deposition material
[0039] [0039]FIG. 8 a is a side view of a microsphere with deposition material loaded on the microsphere.
[0040] [0040]FIG. 8 b is a side view of a capillary bridge between the microsphere and a surface during the deposition of a deposition domain.
[0041] [0041]FIG. 9 is a side view of a deposition domain on an array just after the microsphere has been withdrawn.
[0042] [0042]FIG. 10 is a perspective view of an array of the present invention.
[0043] [0043]FIG. 11 is an outline view of an example scan of an array after exposure to a target medium.
SUMMARY
[0044] A method for the construction of a molecular deposition domain on a surface, comprising, providing a surface, depositing a deposition material on a deposition device, and depositing the deposition material on the surface using said deposition device, forming a molecular deposition domain smaller than one micron in total area.
[0045] Another embodiment comprises method for constructing an array of molecular deposition domains including the steps of providing a surface, providing an at least one deposition material, depositing a first deposition material on a deposition device, depositing the first deposition material on the surface in a known position, forming a first molecular deposition domain smaller than one micron in total area, cleaning the deposition device, and repeating the above steps with an at least one other deposition material, creating an array of two or more deposition domains on said surface.
[0046] Yet another embodiment comprises a method for detecting a target sample, the method comprising, forming a molecular array on a surface, the molecular array including an at least one molecular deposition domain, said at least one molecular deposition domain smaller than one micron in total area, exposing the surface to a sample medium, the sample medium containing one or more target samples which cause a molecular interaction event in one or more of the at least one deposition domain, and scanning the surface using a scanning probe microscope to detect the occurrence of the molecular interaction event caused by the target sample.
[0047] A still further embodiment comprises a molecular array for characterizing molecular interaction events, comprising a surface, and an at least one molecular deposition domain deposited on said surface wherein the spatial address of the domain is less than one micron in area.
[0048] Another embodiment comprises a method for the processing of multiple arrays including forming an array in a substrate, the array comprising a plurality of deposition domains formed of a deposition material, exposing the array to one or more materials which contain an at least one sample molecule that causes a molecular interaction event with one or more of the deposition samples, and scanning the array utilizing a scanning probe microscope to characterize the molecular interaction events that have occurred between the target sample and the deposition material.
[0049] One object of this invention is the construction of relatively small molecular domains with large molecular species.
[0050] Another object of this invention is the construction of molecular arrays comprised of molecular domains, each containing as little as a solitary molecule.
[0051] Another object of the present invention is an apparatus and method for the creation of a molecular array comprised of one or more molecular domains, each with an area smaller than one micron.
[0052] Another object of this invention is the utilization of molecular domain arrays without having to perform a labeling step to allow for the detection of a molecular event.
[0053] Another object of this invention is a molecular deposition array that has an effective screening limit at the single molecule level.
[0054] Another object of the present invention is a method for using an AFM in a high throughput format to detect and evaluate interactions between molecules.
[0055] Another object of this invention is the placement of molecular deposition domains at a defined spatial address.
DETAILED DESCRIPTION
[0056] I. Definitions
[0057] The following are some definitions that may be helpful in understanding the description of the present invention. These are intended as general definitions and should in no way limit the scope of the present invention to those terms alone, but are put forth for a better understanding of the following description.
[0058] A. Deposition Material: This is a selected sample placed on a surface that can be recognized and/or reacted with by a target sample. The deposition material will ideally have a change inflicted upon it by one or more target samples that can be detected by later scanning with an SPM. This is the known material placed in the domain. Examples of deposition materials include, but are not limited to, biomolecules, proteins, a variety of chemicals, DNA, RNA, antibodies, or any other substance recognized by one skilled in the art which may have usefulness within the teaching of the present invention.
[0059] B. Deposition Domain: A deposition domain is a spot on a surface upon which a deposition material is placed. The domain may be of any size, shape, and pattern and may contain as little as one molecule of the deposition material. These deposition domains may alternatively be referred to as “spots” or “points.” The boundary of the domain is defined by the boundary of the material placed therein.
[0060] C. Array: Alternatively referred to using the term “array,” “bioarray,” “molecular array,” or “high density molecular array.” The term array will be used to describe the one or more molecular domains deposited on the surface.
[0061] D. Target Sample: A substance with a particular affinity for one or more deposition domains. These target samples may be natural or man-made substances. The target samples may be known or unknowns present in a solution, gas, or other medium. These target samples may bind to the deposition domain or simply alter the deposition in some other cognizable way. Examples of target samples may include, but are not limited to, antibodies, drugs, nucleic acids, proteins, cellular extracts, antibodies, etc. The target medium may likewise be artificially made or, in the alternative, a biologically produced product.
[0062] E. AFM: As noted above, AFM's are a type of scanning probe microscope. The AFM is utilized in the present invention as an example of an SPM. The invention, however, is not limited for use with one specific type of AFM, but can also be incorporated for use with SPM's of various makes, models, and technological improvements.
[0063] F. Deposition Device: The deposition device of the following description is a modified AFM probe and tip. The basic probe and tip of the AFM is well known to one reasonably skilled in the art. The modified probe and tip that is the deposition device of the present invention may alternatively be referred to herein as “tip,” “probe tip,” or “deposition device.” Other deposition devices can be substituted by one reasonably skilled in the art, including the use of a dedicated deposition device manufactured for the express purpose of sample deposition.
[0064] II. General
[0065] The apparatus and method of the present invention allows for the placement of an at least one deposition sample in an at least one molecular deposition domain forming an array. The method of creating the present invention deposition domain may result in deposition domains smaller than one micron in total area. Furthermore, this method allows the deposition of relatively large molecular species, as large as 1 kilodalton and larger, without shearing or changing the molecular formation. This array can be exposed to a sample medium that may contain a target sample, the presence of which may be ascertained and characterized by detecting molecular interaction events. The molecular interaction event detection may be performed utilizing an atomic force microscope.
[0066] The deposition domains of the present invention may be formed as small or smaller than one micron in area. The present invention allows the direct detection of molecular interaction events in the deposition domain of the array. The molecular interaction event is detected without the need for the labeling of the deposition material or of the target sample. While labeling may still be performed for use with the present invention, the present invention does not require labeling to be utilized.
[0067] The present invention utilizes a scanning probe microscope to interrogate the various deposition domains of the present invention array. As the probe is scanned over a surface the interaction between the probe and the surface is detected, recorded, and displayed. If the probe is small and kept very close to the surface, the resolution of the SPM can be very high, even on the atomic scale in some cases.
[0068] In the present embodiment, an AFM may be used as the deposition tool, but this does not exclude other types of SPM's being used in alternative embodiments. An unmodified AFM probe has a sharp point with a radius of curvature that may be between 5 and 40 nm. The method herein uses a microfabricated deposition device with an apical radius on the order of 10-50 nm. Due to the small radius of curvature of the deposition device used herein, the spot size generated by the present method can range from larger spots to as small as 0.2 microns or smaller. The difficulties with the prior art method need for labeling, such as with radioactivity, fluorescence, enzymatic labeling, etc., are also avoided.
[0069] As one reasonably skilled in the art will appreciate, the molecular material deposited by the present invention may be of almost any size and type. The following materials and methods are not intended to exclude other materials that may be compatible with the present invention, however, the present example is given for better understanding of the scope of the present invention.
[0070] Surface Preparation
[0071] As shown in FIG. 1, block 10 , and FIG. 2, block 18 , a surface may first be provided. The deposition domains that form the array will be constructed on this surface. The surface used for the deposition of the present embodiment molecular domain should facilitate scanning by an AFM as well as facilitate the deposition of the deposition material. A surface which can accept and bind tenaciously to the deposition material may also be desired. The present embodiment utilizes a solid glass substrate. This solid glass substrate may be a glass slide well known to those reasonably skilled in the art. Other embodiments may use other substrates including, but not limited to, mica, silicon, and quartz. The present embodiment may further cover this surface with a freshly sputtered gold layer.
[0072] The ion beam sputtering of gold onto a surface is well known by those reasonably skilled in the art. Sputtering gold may produce an extremely smooth surface upon which a variety of chemistry and molecular binding may be performed. In other embodiments, the gold may be sputtered onto glass coverslips, smooth silicon, quartz or a similar flat surface. The smoothness required of the underlying substrate is a function of the sensitivity requirement of a particular test. For example, detection of a virus particle binding to antibodies on a surface requires only the smoothness of a typical glass coverslip. In contrast, detection of binding of a small ligand to a surface immobilized protein may require a supporting substrate with a surface roughness of one nanometer over an area of several microns.
[0073] In alternative embodiments, other surfaces besides that achieved by gold sputtering may be likewise utilized, such as, but not limited to, glass, Si, modified Si, (poly) tetrafluoroethylene, functionalized silanes, polystyrene, polycarbonate, polypropylene, or combinations thereof.
[0074] The gold of the present embodiment is sputtered onto the glass surface. This area of gold defines the boundary of the present embodiment array. The deposition material will be deposited in domains contained in this area.
[0075] Depositing the Deposition Sample on the Deposition Device
[0076] With reference to FIG. 1 block 12 , FIG. 2 block 20 , and FIG. 3, the deposition of the sample on the deposition device 40 will be described. The basic shape of the deposition device 40 is shown in FIG. 3. Before the deposition material is formed into a molecular domain on the above surface, the deposition material must first be placed onto the deposition device 40 . The deposition device 40 of the present embodiment may be a deposition device 40 and tip 42 commonly utilized by an AFM. The present embodiment starts with a standard silicon-nitride AFM probe under the tradename “DNP Tip” produced by Digital Instruments, Inc. These probes are generally available and well known in the art. In the present embodiment, the deposition device 40 may be first placed on the deposition instrument. A Digital Instrument, Inc., Dimension 3100 may be used in the present embodiment, controlled by a standard computer and software package known in the art.
[0077] In the present embodiment, the deposition instrument may be modified with a microsphere 52 to facilitate the loading (depositing) of the deposition material 56 . While other embodiments may not utilize such a microsphere on the deposition device 40 , attaching a microsphere on the deposition device 40 allows the loading of a greater amount of deposition material upon the deposition device 40 , enabling a greater number of deposition domains 64 to be deposited before reloading with new material. Borosilicate glass spheres up to 25 microns or larger in diameter may be utilized in the present embodiment as the microspohere 52 .
[0078] First, a small amount of epoxy resin is placed upon a surface, usually glass. A standard ultraviolet activated epoxy resin, such as Norland Optical Adhesive #81, may be utilized, though those reasonably skilled in the art may fine other types of epoxies useful as well. The deposition device 40 is moved by the instrumentation and dipped slightly in the epoxy and withdrawn, retaining a small amount of the epoxy on the tip 42 . As shown in FIG. 4, on another surface 50 are placed a number of the microspheres 52 . Using the instrumentation controls, one or more of the borosilicate glass beads is touched by the end of the deposition device 40 . Because of the epoxy, the microsphere 52 sticks to the end of the deposition device 40 as it is pulled away. The deposition device 40 is then exposed to ultraviolet light to set the epoxy and permanently affix the microsphere glass bead 52 to the tip 42 of the deposition device 42 . As shown in FIGS. 5 and 6, the microsphere 52 may bind to the tip 42 of the deposition device 40 in various places without affecting the present invention.
[0079] The present embodiment places one microsphere 52 on the deposition device 40 . This microsphere 52 allows the deposition device 40 to retain more of the material to be deposited on the probe while still allowing the creation of deposition domains 64 on the sub-micron scale. As noted above, as little as one microsphere 52 may be deposited on the tip in the above process. Furthermore, the surface of the microsphere 52 allows for alternative types of surface chemistry to be performed when, in alternative embodiments, the deposition material is being bonded to the surface.
[0080] The microspheres 52 used in the present embodiment are commercially available and well known in the art, ranging in size to smaller than 0.05 microns. With a smaller the microsphere 52 , a smaller deposition domain 64 may be achieved, however less sample can be deposited on the tip at any one time, slowing down the construction of the array. Modification of the deposition device 40 may also be accomplished in a number of alternative ways, including spontaneous adsorption of molecular species, chemical derivitization of the AFM tip followed by covalent coupling of the probe molecule to the tip, or the addition of microspheres to the tip which may be coupled to molecules by standard chemistry. In additional embodiments, a laser may be used to locally heat the deposition device 40 and bond microspheres (such as polystyrene spheres) by a “spot welding” technique.
[0081] As shown in FIG. 1 block 12 , and FIG. 2 block 20 , after the microsphere 52 is placed on the deposition device 40 , the deposition material 56 may be loaded on the deposition device 40 by forming a capillary bridge 60 . The deposition material 56 may be placed on a surface as shown in FIG. 7 a . This large spot of deposition material 56 can be reused a number of times, depending on the number of domains 64 that are to be created. Though not drawn to scale, FIG. 7 a shows material that may have been micro-pipetted onto a surface for loading on the deposition device 40 .
[0082] In one embodiment, the deposition device 40 may be brought into direct contact with the material 56 on the surface. In alternative embodiments, the deposition device 40 and microsphere 52 may be brought into a near proximity to the deposition material 56 on the surface and achieve the same capillary action. The exact distance between the microsphere 52 and the deposition material 56 may vary and still have the formation of a capillary bridge 60 . This depends on conditions like relative humidity, microsphere 52 size, contaminants, etc. In the present embodiment, this distance may vary between touching to several nanometers or more.
[0083] The capillary bridge 60 , shown in FIG. 7 b , may be formed by controlling the humidity by timing a blast of humid gas. Longer bursts may result in a greater amount of material to be placed on the tip. Short bursts allow for less material to be used, but must be long enough to effectively transfer deposition material 56 from the surface 62 to the deposition device 40 . The optimal parameters are determined empirically, however a typical time of exposure to the humid gas is on the order of 500 milliseconds or longer. It has also been noted that a capillary bridge 60 may be spontaneously generated when the relative humidity of the air is more than approximately 30%. In cases such as this, it may be advantageous to have a controlled dry environment or to have a stream of dry air flowing over the surface which is interrupted by the humid blast of gas which forms the capillary bridge 60 . In other embodiments, this spontaneous capillary bridge 60 can be used to deposit the deposition material 56 , though less control of the process may result.
[0084] In the present invention the humidity may be controlled by several methods known to those reasonably skilled in the art. The present embodiment incorporates a small tube and argon gas source which creates the bridge by rapidly increasing the level of humidity around the probe and the deposition material. The tube of the present embodiment may be a flexible polymer material, such at “Tygon” tubing, with an inner diameter of 0.5 to 1.0 cm. This material is readily available, but other materials that will not introduce contaminants into the deposition material would likewise suffice. The small tube must first be filled with water.
[0085] The water used in the present embodiment should be of a highly purified nature, such as purified water with a resistance of 18 megaohms or more. It should be free of particulates by filtration and is usually sterilized by filtration and or autoclaving. Additionally, an argon gas source may be positioned at one end of the tube and may be controlled by the action of a needle valve and solenoid.
[0086] The water is then drained from the tube, leaving a humid gas in the tube. When the humidity blast is desired, the solenoid is activated to pulse a discrete amount of humidified argon through the tube and over the probe 40 , deposition material 56 , and surface 62 . As shown in FIG. 7 b , the capillary bridge 60 may be formed between the surface 62 and the deposition device 40 . The deposition device 40 is then moved away from the surface 62 , leaving a small amount of the deposition material 56 on the deposition device 40 , as shown in FIG. 8 a.
[0087] As shown in FIG. 8 a , the deposition material 56 is now on the deposition device 40 . Whether the deposition material 56 adsorbs onto the microsphere's 52 surface, the pores, or some other area, may vary depending on the type of microsphere 52 and the deposition material 54 . As shown in FIG. 1 block 14 , the deposition material 56 may now be dried on the deposition device 40 . The drying may be immediate and spontaneous due to the relatively little amount of wet material on the surface of the deposition device 40 . This is, of course, dependent on the relative humidity of the surrounding air. Drying the deposition material 56 on the microsphere 56 may facilitate the deposition of the material 56 on the surface 62 as laid out in the next step. For labile samples, drying could result in inactivation, and should be avoided, but this is not the case for robust samples such as antibodies, peptides and nucleic acids.
[0088] In an alternative embodiment, the deposition tip may be loaded with the deposition material 56 by direct immersion. The tip of the probe may be immersed in a solution containing up to 50% glycerol, 0.1-5 mg/ml of the deposition sample, and a buffer-electrolyte such as Tris-HCl at pH 7.5. A small amount of the above solution may be made by standard bench chemistry techniques known to those skilled in the art. Typically 1-10 microliters are made. Because of the nature of solutions, when the probe is dipped into the solution and withdrawn a small amount of the solution will cling to the surface of the tip in a manner known to those reasonably skilled in the art. In still further embodiments, other solutions, such as 10 mM NaCl and 1 mM MgCl 2 , phosphate buffered saline, or a sodium chloride solution, may be substituted by those reasonably skilled in the art. Alternative methods for loading the deposition material 56 on the deposition device 40 include spraying, chemically mediated adsorption and delivery, electronically mediated adsorption and delivery, and either passive or active capillary filling.
[0089] In still further embodiments, other probes may also be used, for example, AFM probes lacking a tip altogether (tipless levers), may also be used. The type of probe used may impact the spatial dimensions of the deposition domain 64 and may be influenced by the choice of the deposition sample.
[0090] Depositing the Sample on the Surface
[0091] The next step in creating the deposition domain 64 and array 66 is depositing hte sample on the surface. See FIG. 1 block 16 and FIG. 2 block 22 . Varying the humidity level surrounding the deposition device 40 and deposition material 56 may be taken advantage of to deposit the deposition material 56 onto the surface in a deposition domain 64 less than one micron in area. The capillary bridge 60 is illustrated by FIG. 8 b . This step may be performed in much the same way as depositing the deposition material 56 on the deposition device 40 . The degree of binding to the surface and the deposition device 40 is a function of the hydrophilicity and hydrophobicity of the two surfaces. Therefore, it may often be desirable to use deposition tools and surfaces that are free of oils and other hydrophobic contaminants to facilitate wetting of both surfaces.
[0092] Utilizing the AFM and the control computer and software, the deposition device 40 , with the deposition material 56 , may be brought into contact, or close proximity, with the deposition surface. The humid gas may then be released by activation of the solenoid. In the present embodiment the humidity is ramped up, and the capillary bridge 60 formed, for a time of approximately 400 milliseconds or less, depending on the amount of material the user wishes to deposit. The spots are on the sub-micron scale because the contact surfaces are on the order of microns or smaller and the degree of sample diffusion (which determines the final size of the deposition domain) is carefully controlled by regulating the amount and timing of the humid gas burst. When depositing the deposition sample 56 on the surface, in order to better control the length of time the capillary bridge 60 exists, a tube of dry air may be blown over the area by a solenoid in rapid succession after the humid air. This results in a very short burst of humid air, a capillary bridge 60 , and then the termination of the capillary bridge 60 , all in a very short time period. As illustrated in FIG. 9, when the deposition device 40 is withdrawn, and the bridge 60 severed, a very small amount of the deposition material 56 has been deposited on the surface 62 in a deposition domain 64 . The transfer of large macromolecules may be achieved utilizing the burst of humid gas. As will be appreciated by one reasonably skilled in the art, the capillary bridge 60 may be broken by withdrawing the deposition device 40 or by the blast of dry air.
[0093] Because of the fine control of the deposition device 40 that may be possible with the AFM instrumentation, the exact surface spot in which the deposition takes place may be noted. Noting the surface point for each deposition domain 64 may ameliorate the detection of the molecular interaction event caused by the target sample. The pattern writing program can be one that is provided by an AFM manufacturer (e.g., the Nanolithography program provided by Digital Instruments, Inc.) or it can be created in-house. In the latter case, one example is to use a programming environment such as Lab View (National Instruments) with associated hardware to generate signal pulses which control the positioning of the deposition probe.
[0094] The steps laid out above produce the deposition domain 64 of the present embodiment. Repeating these steps with one or more deposition materials 56 , FIG. 2 block 26 , produces the array 66 of the present invention. This array is shown in FIG. 10. The number and size of the deposition domains 64 may be varied depending on the desire of the user.
[0095] One advantage to the present embodiment is the small size of the deposition domain 64 produced by the method. Furthermore, because of the manner in which the array 66 is produced, the user may be able to record and track the position of each of the particular deposition domains 64 . Finally, the above method allows the deposition of as little as a single macromolecule, which previous methods were unable to perform.
[0096] Once the array 66 has been formed, the user may desire to immediately utilize the array 66 on site, or may desire shipment of the array 66 for exposure to a sample medium at another location. The array 66 produced by the above steps may be ideal for shipment to a location, exposure, and return shipment for the scanning by an AFM.
[0097] Subsequent Depositions
[0098] In an alternative embodiment, the probe may be reloaded with a second deposition material 56 after one or more molecular domains are created with the first deposition material 56 . FIG. 2 block 26 . Using the probe with a variety of deposition materials 56 enables the creation of a number of deposition domains 64 on one surface. The different deposition materials 56 in the molecular domains that are deposited on the surface form the array 66 of the present invention. Because of the size of the molecular domain containing the deposition material 56 , the molecular domains can be placed on the surface in a an ultra high density array 66 , as shown in FIG. 10. In the present embodiment of this invention, the pitch (the distance from the center of one domain to the center of the next domain) of the molecular domains may be as small or smaller than one micron. The array 66 produced with these small molecular domains may be easily scanned by the AFM array 66 after the array 66 is exposed to the sample medium containing the target sample in the next step. Furthermore, the small sized array 66 requires exposure to a smaller amount of the sample medium of the next step, conserving both the deposition material 56 and the medium material.
[0099] The number of times the probe may be reloaded in this alternative embodiment may be only limited by the surface size and the number of samples the user desires to deposit. As will be appreciated by those skilled in the art, this ultra high density array 66 presents a unique advantage.
[0100] Cleaning the Probe
[0101] Before the probe is reloaded with subsequent deposition samples, the probe must be cleaned. FIG. 2 block 24 . The probe of the present embodiment AFM may be cleaned in several ways. In the present embodiment, the very tip of the probe is immersed in a small aliquot of a cleaning solution. The present embodiment cleaning step utilizes pure water as the solution. A few microliters of water is pipetted onto a surface and, using the instrunentation's piezo device (which is utilized to help the AFM scan surfaces), the tip is oscillated at up to 1000 Hz or more. Resonating the probe at 1000 hertz will effectively sonicate the tip, helping to effectuate reusing the tip to deposit other deposition materials 56 .
[0102] Exposing the Array to a Sample Medium
[0103] Once a high density array 66 is formed by the present invention, the array 66 may be exposed to a sample medium. FIG. 2 block 28 . The sample medium may contain a target sample that the user has placed therein. In other types of experiments, the user may be looking for the presence of an unknown target sample, utilizing the array 66 of the present invention to test for its presence. The usefulness of such arrays 66 are well known to those reasonably skilled in the art.
[0104] The array 66 may be dipped in a solution or exposed to a gas. The solution may include, but is not limited to, waste water, biological materials, organic or inorganic user prepared solutions, etc. The exposure time of the array 66 to the medium depends on what types of molecular interaction events the user may be studying. The target sample tested for should ideally cause a readable molecular change in one or more of the deposition materials 56 of the molecular domains placed on the array 66 . These molecular changes may include binding, changes in stereochemical orientation in morphology, dimensional changes in all directions, changes in elasticity, compressibility, or frictional coefficient, etc. The above changes are what the AFM scans and reads in the next step of the present embodiment.
[0105] Molecular Event Detection
[0106] After the molecular deposition array 66 is exposed to the test medium, it may be scanned by the AFM. See FIG. 2 block 30 . Use of an AFM in this manner to characterize a material deposited on a surface is well known to those reasonably skilled in the art. The present embodiment may utilize one scan for every deposition domain 64 of the array 66 to look for changes in the recorded features of the domains. Furthermore, the AFM may look at specific portions of the array 66 using site locators. As will be appreciated by one skilled in the art, various methods may be used to undertake the scanning of the array 66 of the present invention.
[0107] After the scan is taken, the scan must be analyzed. FIG. 2, block 32 . The present embodiment utilizes the detection of changes in height at defined spatial addresses, as described by Jones et al., supra. As shown in FIG. 11, height changes only occur at those addresses containing deposition material 56 to which the target sample is capable of binding. Since the identity of the molecules at each of the sample addresses is known, this process immediately identifies those deposition materials 56 capable of binding to the target sample. In FIG. 11, point 66 shows the normal height of the deposition domain 64 as scanned by the AFM. Point 68 shows how the AFM will recognize some feature that the molecular interaction event has affected in the deposition domain 64 .
[0108] In addition, the AFM can measure whether new materials have bonded to the deposition material 56 by testing for changes in shape (morphology) as well as changes in local mechanical properties (friction, elasticity, compressibility, etc.) by virtue of changes in the interaction between the probe and the surface. The typical parameters detected by an AFM include height, torsion, frequency (the oscillation frequency of the AFM probe in AC modes of operation), phase (the phase shift between the driving signal and the cantilever oscillation in AC modes) and amplitude (the amplitude of the oscillating cantilever in AC modes of operation).
[0109] The AFM scan may also be used to tell when the probe is interacting with different forces of adhesion (friction) at different domains on the surface. This interaction force is a consequence of the interaction between the molecules on the probe and on the surface. When there is a specific interaction, the force value is typically higher than for non-specific interactions, although this may not be universally true (since some non-specific interactions can be very strong). Therefore, it may be useful to include both known positive and negative control domains in the scan area to help distinguish between specific and non-specific force interactions. The target sample may affect the deposition material 56 that can be read by this scanning technique. A still further embodiment may directly measure the interaction forces between a molecular probe coupled to the AFM tip and the surface. The direct measurement of molecular unbonding forces has been well described in the art in addition to measuring changes in the elasticity.
[0110] In the screening methods described above, once it has been established that a molecular binding event has occurred, changes in the degree of binding upon introduction of additional sample molecules may also be analyzed. The potential for a third molecular species to enhance or inhibit a defined molecular interaction is of utility in locating new drugs and other important effectors of defined molecular interactions.
[0111] In the above examples an AFM is used for illustration purposes. The type of deposition instrumentation incorporated into the present invention is not limited to AFM's, or other types of SPM's. In one alternative embodiment, a dedicated deposition instrument may be used which may provide for extremely accurate control of the deposition probe. In this alternative embodiment, a DC stepper motor and a piezoelectric motion control device may be incorporated for sample and probe control. In still further embodiments, a force feedback system may be included to minimize the force exerted between the deposition tool and the surface.
[0112] One advantage to the present invention is the elimination of the labeling step required in other array 66 techniques. Radioactive and fluorescent labeling may be cost prohibitive and complex. The present invention eliminates the need for the labeling of molecular deposition domains 64 in an array 66 .
[0113] Another advantage to the present invention is the creation of molecular domains in an array 66 wherein each domain has a deposition area of less than one micron. Since the size of each domain is extremely small, a large number of domains may be placed in a small area, requiring less materials, a smaller medium sample for exposure, and the ability to perform a quicker scan.
[0114] Another advantage to the present invention array 66 is the ability to quickly scan for multiple molecular events in a reasonably short period of time.
[0115] III. Alternative Deposition Examples
[0116] The following are a few of the variations in the deposition method and array 66 apparatus that may be used within the scope of the present invention. These examples are given to show the scope and versatility of the present invention and are not intended to limit the invention to only those examples given herein. In each of these examples, the deposition material 56 may be deposited on the deposition device 40 and then to the surface utilizing the method described above, however the surface may be coated with other materials that will react in some way with the deposition material 56 , to bind the latter to the surface in the deposition domain 64 .
[0117] A. Surface Modification
[0118] One alternative embodiment for the covalent tethering of biomaterials to a surface for use in the present invention may be to use a chemically reactive surface. Such surfaces include, but are not limited to, surfaces with terminal succinimide groups, aldehyde groups, carboxyl groups, vinyl groups, and photoactivatable aryl azide groups. Other surfaces are known to those reasonably skilled in the art. Biomaterials may include primary amines and a catalyst such as the carbodiimide EDAC (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide). Furthermore, the spontaneous coupling of succinimide, or in the alternative, aldehyde surface groups, to primary amines at a physiological pH may be incorporated for attaching molecules to the surface. In still another embodiment, photoactivatable surfaces, such as those containing aryl azides, may be utilized. These photoactivatable surfaces form highly reactive nitrenes that react promiscuously with a variety of chemical groups upon ultraviolet activation. Placing the deposition sample on the surface and then activating the material can create deposition domains 64 in spots or patterns, limited only by the light source activated.
[0119] Another embodiment for the tenacious and controlled binding of biomaterials to surfaces is to exploit the strong interactions between various biochemical moieties. For example, histidine binds tightly to nickel. Therefore, both nucleic acid and protein biomaterials may be modified using recombinant methods to produce runs of histidine, usually 6 to 10 amino acids long. This His-rich domain then allows these molecules to bind tightly to nickel coated surfaces. Alternatively, sulfhydryl groups can be introduced into protein and nucleic acid biomaterials, or preexist there, and can be used to bind the biomaterials to gold surfaces by virtue of extremely strong gold-sulfur interaction. It is well documented that gold binds to sulfur with a binding force comparable to that of a covalent bond. Therefore, gold-sulfur interactions have been widely exploited to tether molecules to surfaces. Jones, V. W., J. R. Kenseth, M. D. Porter, C. L. Mosher, and E. Henderson, Microminiaturized Immunoassays Using Atomic Force Microscopy and Compositionally Patterned Antigen Arrays 66, Anal Chem. 1998, p. 1233-41.
[0120] B. APTES
[0121] In this alternative embodiment, the surface may be treated with APTES (aminopropyl triethoxy silane). The APTES placed on the surface may present positively charged amino groups that can bind tightly to a negative charge. Materials such as DNA and RNA containing negatively charged groups may therefore bond to the surface after the APTES treatment. The details of the adsorption mechanism involved in this spontaneous attachment are not well defined. Therefore, in alternative embodiments, it may be advantageous to deposit biomaterials onto surfaces that can be covalently or otherwise tenaciously coupled to the target sample. DNA and RNA bind through interaction between their negative net charge and the net positive charge of the APTES surface.
[0122] C. Photochemical Sample Deposition
[0123] In this alternative embodiment, glass surfaces may be modified sequentially by two compounds, aminopropyltriethoxysilane (APTES) and N-5-azido-2-nitrobenzoyloxysuccinimide (ANB-NOS). The glass may first be treated with APTES to generate a surface with protruding amino groups (NH 2 ). These groups may be then reacted with the succinimide moiety of ANB-NOS in the dark. These steps produce a surface with protruding nitrobenzene groups. The photosensitive surface may be then reacted with the first deposition material 56 in the dark, then a focused light source, like a laser, may be used to illuminate a portion of the surface. These acts result in localized covalent binding of the first deposition material 56 to the surface. The deposition material 56 not bonded to the surface may then be washed away and second deposition material 56 added by repeating the process. Reiteration of this process results in the creation of a biomolecular array 66 with address dimensions in the 1 micron size range. A limitation of this deposition method is that the sample size is dependent on the size of the illuminating light field.
[0124] A variation of the above embodiment may be to utilize the deposition device 40 and humidity ramping deposition technique described to place various molecular species at defined locations in the dark. After construction of the desired array 66 , the entire surface is exposed to light, thereby cross linking the molecular species at discrete spatial domains. This process may overcome the spatial limitation imposed by use of a far field laser or other type of light beam.
[0125] D. Photocoupling
[0126] In this embodiment a near field scanning optical microscope (NSOM) may be used to supply the light energy necessary to accomplish photocoupling of the sample molecule to a surface at a defined spatial address. The NSOM may overcome the diffraction limit which constrains the address size created by far field photocoupling as described in Example 2. The photoactive surface is prepared as described in Example II. The first molecule to be coupled is added to the surface and subjected to a nearfield evanescent wave emanating from the aperture of the NSOM. The evanescent wave energy may then activate the photosensitive surface and result in coupling of the sample molecules to a spatial address in the 10 to 100 nm size range. The first sample molecule is washed away and the process repeated with a second sample molecule. Reiteration of this process may result in the production of an array 66 of sample molecules coupled at spatial addresses with submicron dimensions.
[0127] An alternative approach may be to utilize both the sample manipulation and near field light delivery capabilities of the NSOM. In this approach, the NSOM probe may be first loaded with a molecular species as described in Example I. Then the same probe is used to provide the light energy to couple the molecule to the surface. The probe may then be washed and reused to create a spatial array 66 of molecular species covalently coupled to defined domains.
[0128] One advantage of coupling the deposition material 56 to the surface may be that the molecule may remain attached at a defined spatial domain even under stringent wash and manipulation conditions. Moreover, by coupling the molecule, the orientation of the molecules on the surface may be controlled by the careful selection of a tethering method.
[0129] Yet another advantage to coupling the molecule is that by controlling the coupling chemistry, the minimization of the chances of surface induced molecular denaturation may be achieved. Coupling the molecules to the surface may be especially advantageous when depositing biomolecules.
[0130] The information and examples described herein are for illustrative purposes and are not meant to exclude any derivations or alternative methods that are within the conceptual context of the invention. It is contemplated that various deviations can be made to this embodiment without deviating from the scope of the present invention. Accordingly, it is intended that the scope of the present invention be dictated by the appended claims rather than by the foregoing description of this embodiment.
[0131] All publications cited in this application are incorporated by reference in their entirety for all purposes.
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The invention is a method for the formation and analysis of novel miniature deposition domains. These deposition domains are placed on a surface to form a molecular array. The molecular array is scanned with an AFM to analyze molecular recognition events and the effect of introduced agents on defined molecular interactions. This approach can be carried out in a high throughput format, allowing rapid screening of thousands of molecular species in a solid state array. The procedures described here have the added benefit of allowing the measurement of changes in molecular binding events resulting from changes in the analysis environment or introduction of additional effector molecules to the assay system. The processes described herein are extremely useful in the search for compounds such as new drugs for treatment of undesirable physiological conditions. The method and apparatus of the present invention does not require the labeling of the deposition material or the target sample and may also be used to deposit large size molecules without harming the same.
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