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CROSS REFERENCE RELATED TO APPLICATION
[0001] This application claims the benefit of the following provisional application: U.S. Ser. No: 60/184,020, filed Feb. 22, 2000, under 35 USC 119(e)(i).
FIELD OF THE INVENTION
[0002] The present invention relates to (2S)-enantiomers of 2-aminoindan derivatives and a novel process for the preparation of them.
BACKGROUND OF THE INVENTION
[0003] Schizophrenia is a common and devastating mental disorder which is currently an unmet medical need. It is characterized by so-called positive (hallucinations, delusions) and negative (blunted affect, poverty of speech, social & emotional withdrawal) symptoms, as well as cognitive deficits (working memory impairment). About 1% of the world population is affected, men and women equally, with typical onset between ages 15 and 25. Antagonists of the neurotransmitter dopamine are known to block psychosis. The present invention provides compounds of formula I (wherein each R is independently C 1 -C 8 alkyl), a highly selective D 3 receptor antagonist, for the treatment of Schizophrenia and other CNS diseases.
[0004] Racemic forms of formula I and their preparations have been disclosed in PCT publication WO 97/45403. The present invention has discovered that the (2S)-enantiomer of formula I is the form that possesses the superior desirable bioactivity. The present invention also provides a process for the synthesis, in a large scale, of said (2S)-enantiomer in a highly enantiomerically enriched form, which solved an extremely challenging problem of a long period of time.
INFORMATION DISCLOSURE
[0005] PCT International Publication No. W097/45403 discloses aryl substituted cyclic amines as selective dopamine D3 ligands.
[0006] U.S. Pat. No. 5,708,018 discloses 2-aminoindans as selective dopamine D3 ligands.
SUMMARY OF THE INVENTION
[0007] The present invention provides compounds of formula I:
[0008] or a pharmaceutically acceptable salt thereof wherein each R is independently C 1 -8 alkyl.
[0009] More preferably, a compound of formula I of the present invention is (2S)-(+)-2-(dipropylamino)-6-ethoxy-2,3-dihydro-1H-indene-5-carboxamide or a pharmaceutically acceptable salt thereof.
[0010] In another aspect, the present invention also provides:
[0011] a process for the preparation of (2S)-enantiomers of formulas I in a highly enantiomerically enriched form;
[0012] novel intermediates in a highly enantiomerically enriched form useful for preparing compounds of formula I;
[0013] a pharmaceutical composition comprising a compound of formula I, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier (the composition preferably comprises a therapeutically effective amount of the compound or salt),
[0014] a method for treating a disease or condition in a mammal wherein a D 3 receptor is implicated and modulation of a D 3 receptor function is desired comprising administering a therapeutically effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof to the mammal;
[0015] a method for treating or preventing anxiety, obesity, depression, schizophrenia, a stress related disease (e.g. general anxiety disorder), panic disorder, sleep disorders, a phobia, mania, obsessive compulsive disorder, post-traumatic-stress syndrome, immune system depression, a stress induced problem with the gastrointestinal or cardiovascular system, or sexual dysfunction in a mammal comprising administering a therapeutically effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof to the mammal;
[0016] a method for treating or preventing ADHD (attention deficit hyperactivity disorder), migraine, substance abuse (including smoking cessation), cognitive deficits, memory impairment, alzheimer's disease, movement disorders including choreatic movements in huntington's disease or motor complications such as dystonias and dyskinesias in Parkinson's disease, extrapyramidal side effects related to the use of neuroleptics, and “Tics” including Tourette's syndrome in a mammal comprising administering a therapeutically effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof to the mammal.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The following definitions are used, unless otherwise described.
[0018] The term alkyl refer to both straight and branched groups, but reference to an individual radical such as “propyl” embraces only the straight chain radical, a branched chain isomer such as “isopropyl” being specifically referred to.
[0019] The carbon atom content of various hydrocarbon-containing moieties is indicated by a prefix designating the minimum and maximum number of carbon atoms in the moiety, i.e., the prefix C ij indicates a moiety of the integer “i” to the integer “j” carbon atoms, inclusive. Thus, for example, C 1 - 8 alkyl refers to alkyl of one to eight carbon atoms, inclusive.
[0020] Mammal refers to human or animals.
[0021] Pharmaceutically acceptable salts refer to organic acid addition salts such as tosylate, methanesulfonate, acetate, citrate, malonate, tartarate, succinate, benzoate, ascorbate, α-ketoglutarate, α-glycerophosphate, or suitable inorganic salts including hydrochloride, hydrobromide, sulfate, nitrate, bicarbonate, and carbonate salts, etc.
[0022] The term “chiral salt” refers to a salt containing a chiral acid. The term “chiral acids” refers to the acids having one or more chiral centers. Examples of chiral acids are tartaric acid, di-benzoyltartaric acid, di-para-toluoyltartaric acid, camphorsulfonic acid, and mandelic acid. The preferred chiral acid is mandelic acid.
[0023] All temperatures are in degrees Centigrade.
[0024] [α] D 25 refers to the angle of rotation of plane polarized light (specific optical rotation) at 25° C. with the sodium D line (589 A).
[0025] The compounds of formula I are active orally or parenterally. Orally the formula I compounds can be given in solid dosage forms such as tablets or capsules, or can be given in liquid dosage forms such as elixirs, syrups or suspensions as is known to those skilled in the art. It is preferred that the formula I compounds be given in solid dosage form and that it be a tablet.
[0026] Typically, the compounds of formula I can be given in the amount of about 0.5 mg to about 250 mg/person, one to three times a day. Preferably, about 5 to about 50 mg/day in divided doses.
[0027] The exact dosage and frequency of administration depends on the particular compound of formula I used, the particular condition being treated, the severity of the condition being treated, the age, weight, general physical condition of the particular patient, other medication the individual may be taking as is well known to those skilled in the art and can be more accurately determined by measuring the blood level or concentration of the active compound in the patient's blood and/or the patient's response to the particular condition being treated.
[0028] Thus, the subject compounds, along with a pharmaceutically-acceptable carrier, diluent or buffer, can be administrated in a therapeutic or pharmacological amount effective to alleviate the central nervous system disorder with respect to the physiological condition diagnosed. The compounds can be administered intravenously, intramuscularly, topically, transdermally such as by skin patches, buccally or orally to man or other vertebrates.
[0029] The compositions of the present invention can be presented for administration to humans and other vertebrates in unit dosage forms, such as tablets, capsules, pills, powders, granules, sterile parenteral solutions or suspensions, oral solutions or suspensions, oil in water and water in oil emulsions containing suitable quantities of the compound, suppositories and in fluid suspensions or solutions.
[0030] For oral administration, either solid or fluid unit dosage forms can be prepared. For preparing solid compositions such as tablets, the compound can be mixed with conventional ingredients such as talc, magnesium stearate, dicalcium phosphate, magnesium aluminum silicate, calcium sulfate, starch, lactose, acacia, methylcellulose, and functionally similar pharmaceutical diluent or carrier materials. Capsules are prepared by mixing the compound with an inert pharmaceutical diluent and filling the mixture into a hard gelatin capsule of appropriate size. Soft gelatin capsules are prepared by machine encapsulation of a slurry of the compound with an acceptable vegetable oil, light liquid petrolatum or other inert oil.
[0031] Fluid unit dosage forms for oral administration such as syrups, elixirs, and suspensions can be prepared. The forms can be dissolved in an aqueous vehicle together with sugar, aromatic flavoring agents and preservatives to form a syrup. Suspensions can be prepared with an aqueous vehicle with the aid of a suspending agent such as acacia, tragacanth, methylcellulose and the like.
[0032] For parenteral administration, fluid unit dosage forms can be prepared utilizing the compound and a sterile vehicle. In preparing solutions, the compound can be dissolved in water for injection and filter sterilized before filling into a suitable vial or ampoule and sealing. Adjuvants such as a local anesthetic, preservative and buffering agents can be dissolved in the vehicle. The composition can be frozen after filling into a vial and the water removed under vacuum. The lyophilized powder can then be sealed in the vial and reconstituted prior to use.
[0033] The present invention provides a process for preparing compounds of formula I in a highly enantiomerically enriched form as depicted in Scheme I. The starting material I-1 in Scheme I can be prepared according to the procedures described in Chart A of U.S. Pat. No. 5,708,018.
[0034] In step 1, compound I-1 is converted to compound I-2 as a racemic mixture via catalytic hydrogenation in the presence of an appropriate catalyst, such as palladium on carbon, W-2 Raney nickel or platinum on sulfide carbon, in an appropriate solvent, such as ethanol, THF, ethyl acetate or combinations thereof. The desired enantiomer I-2b can be obtained by treating structure 1-2 with an appropriate chiral acid in an appropriate solvent to form the corresponding chiral salt complex, which subsequently crystallizes from the solvent. Resolutions to separate an individual enantiomer I-2a or I-2b from a racemic mixture often pose a significant challenge in the quest to obtain enantiomerically pure compound. In general, a wide variety of enantiomerically pure acids can provide some measure of enantiomer enrichment. However, the choice of the particular chiral acid and solvent system proves very important to the efficiency of the resolution (enantiomeric purity and chemical yield). The preferred chiral acids in the present invention for the resolution include tartaric acid, di-benzoyltartaric acid, di-para-toluoyltartaric acid, camphorsulfonic acid, and mandelic acid. The most preferred chiral acid is mandelic acid. An examination of resolving acids and solvent systems indicate that (R)-(−)-mandelic acid and (1R)-(−)-10-camphorsulfonic acid perform very well for the resolution of racemic 1-2 to induce the crystallization of almost enantiomerically pure I-2b, with (R)-(−)mandelic acid being preferred. Note that it is not necessary to obtain enantiomer I-2b as 100% pure enantiomeric material at this stage of the synthesis since subsequent crystallization procedures in the following procedures will serve to provide a slight upgrade to the final enantiomeric purity. It will be apparent to those skilled in the art that other chiral acids commonly used to perform resolution of amines may also be useful for this resolution. Solvent systems in the present invention, which are found to be useful to optimize the recovery of compound I-2b, include alcohol solvents such as methanol, ethanol, isopropanol, etc. as well as co-solvents of alcohol(s), acetonitrile (ACN), or water in various proportions such as tetrahydrofuran (THF), ether, methyl tertiary butyl ether (MTBE), dimethoxyethane (DME), etc. The preferred solvent system in combination with (R)-(−)-mandelic acid is a mixture of methanol and tetrahydrofuran.
[0035] Next, alkylation of I-2b, in a form of free base or chiral salt complex, with an alkylation agent in the presence of an appropriate base and an appropriate polar solvent system at a temperature in a range of about 20° C. to 90° C. provides compound I-3. The appropriate base includes K 2 CO 3 , Na 3 PO 4 , Na 2 B 4 O 7 , etc. The preferred base is Na 3 PO 4 . The appropriate solvent includes ACN, dimethylformamide (DMF), or THF. The preferred solvent is ACN. The preferred temperature is in a range of from about 60° C. to about 75° C. Compound 1-3 is then converted to compound I-4 by acetylation followed by hydrogenolysis in the presence of an appropriate catalyst, such as palladium on carbon or platinum on sulfide carbon, and an appropriate acetylation reagent such as acetic anhydride, or acetyl chloride with catalytic dimethylaminopyridine, in an appropriate solvent, such as acetic acid, an alcohol, water or combinations thereof, at a temperature in a range of from about 20° C. to reflux. The preferred condition for this reaction is in acetic anhydride/acetic acid at a temperature in a range of from about 55° C. to about 70° C. Bromination of compound I-4 with a brominating reagent in the presence of an acid and a polar solvent system at a temperature in a range of from about −78° C. to about room temperature provides compound I-5. The instant bromination provides an unexpected improvement in regioselectivity for bromination at the desired position by using an appropriate brominating reagent. A suitable brominating reagent may be Br 2 , dibromantin, N-bromosuccinimide (NBS), pyridinium tribromide (pyrHBr 3 ). The preferred brominating reagent is pyridinium tribromide. The acid in the reaction is preferably a strong acid such as HBr, H 2 SO 4 , TiCl 4 , TFA, MeSO 3 H, Cl 3 CCO 2 H, Cl 2 CCO 2 H, or citric acid. The more preferred acid is TFA. The suitable polar solvent may be ACN, DMF, EtOAc, an alcohol such as methanol, CH 2 Cl 2 , MTBE, THF, etc. The preferred solvent is CH 2 Cl 2 . The preferred temperature is in a range from about −15° C. to room temperature. Finally, carboxamidation I-5 in the presence of transition metal such as palladium, palladium on carbon or palladium acetate and associated ligands such as mono or bidentate phosphines in an appropriate solvent with an appropriate base at a temperature in a range from about 70° C. to about 140° C. provides the desired compound I-6. Preferred ligands include triphenylphosphine, tri-orthotolulyphosphine, or 1,3-bis(diphenylphosphino)propane. Preferred temperature is in a range from about 95° C. to about 105° C. The appropriate solvents include dimethylformamide, dioxane, toluene, dimethoxyethane, dimetylacetamide, etc. The preferred solvent is dimethylformamide. The appropriate base include potassium carbonate, tertiary amine bases, Na 3 PO 4 , LiHMDS, Li-amides, alkoxides, etc. The preferred base is potassium carbonate.
[0036] Without further elaboration, it is believe that one skilled in the art can, using the preceding description, practice the present invention to its fullest extent. The following detailed example describe how to prepare the various compounds and/or perform the various processes of the invention and are to be construed as merely illustrative, and not limitations of the preceding disclosure in any way whatsoever. Those skilled in the art will promptly recognize appropriate variations from the procedures both as to reactants and as to reaction conditions and techniques.
EXAMPLE
Preparation of (2S)-(+)-2-(Dipropylamino)-6-ethoxy-2,3-dihydro-1H-indene-5-carboxamide
[0037] [0037]
[0038] Step 1: Preparation of 4-ethoxycinamic acid
[0039] 4-Ethoxybenzaldehyde (1) is condensed with malonic acid in the presence of base (Knovenagel reaction) to obtain the cinnamic acid derivative 2. This is accomplished by dissolving 1 in pyridine with 0.15 eq. of piperidine and heating the resulting solution to 50-135° C. (preferably 105-125° C.) after which a solution of malonic acid (2 eq.) dissolved in pyridine is added in a slow stream. Approximately 40% of the pyridine is slowly distilled off and the heating continued at 125° C. until TLC indicated that all of 1 has been consumed. Cool to 40° C. and add excess concentrated hydrochloric acid, keeping the temperature at around 40° C. Cool to below room temperature and filter the solid product (2), washing with water and then drying.
[0040] [0040] 1 H NMR (300 MHz, CDCl 3 ) δ1.43 (t, J=7.0 Hz, 3 H), 4.07 (q, J=7.0 Hz, 2 H) 6.31 (d, J=16.0 Hz, 1 H), 6.90 (d, J=8.8 Hz, 2 H), 7.49 (d, J=8.7 Hz, 2 H), 7.74 (d, J=15.9 Hz, 1 H).
[0041] Step 2: Preparation of 4-ethoxycinnamic acid
[0042] 4-Ethoxycinnamic acid (2) is hydrogenated at 40 p.s.i. with catalytic 5% palladium on carbon in tetrahydrofuran solvent to obtain 3-(4-ethoxyphenyl)propionic acid (3). A sample is recrystallized from ethyl acetate/hexane to obtain an analytically pure sample (m.p. 101-103° C.).
[0043] [0043] 1 H NMR (300 MHz, CDCl 3 ) δ1.40 (t, J=7.0 Hz, 3 H), 2.65 (t, J=7.7 Hz, 2 H 2.90 (t, J=7.7Hz, 2 H), 4.01 (q, J=7.0Hz, 2 H), 6.83 (d, J=8.6Hz, 2 H), 7.12 (d, J=8.6 Hz,2H).
[0044] Step 3: Preparation of 6-ethoxy-1-indanone
[0045] To carboxylic acid 3 is added thionyl chloride (2 eq.) and catalytic dimethylformamide. The solution is stirred until analysis indicated that all of the carboxylic acid had been converted to the acid chloride. Remove volatile reagents under vacuum. The acid chloride is dissolved in dichloromethane and added to a slurry of aluminum chloride (1.1 eq.) in dichloromethane over 15-60 minutes. The resulting mixture is heated to reflux for 30 minutes (until analysis indicated that all of the starting material had been consumed) and then cooled to 0−15° C. Water is added slowly to quench the reaction and then the mixture is extracted. The organic layer is washed with saturated aqueous sodium bicarbonate and the organic solution is stripped of dichloromethane solvent under vacuum to afford a residue that is redissolved in methyl t-butyl ether and then dried with magnesium sulfate. The solution is filtered and the solvent removed under vacuum to afford solid 4. The solid could be recrystallized from octane to afford an analytical sample (m.p. 57-58° C.).
[0046] [0046] 1 H NMR (300 MHz, CDCl 3 ) δ1.41 (t, J=7.0 Hz, 3 H), 2.66-2.71 (m, 2 H), 3.04 (t, J=5.7Hz, 2H), 4.04 (q, J=7.0Hz, 2 H), 7.13-7.18 (m, 2 H), 7.32-7.35 (m, 1 H).
[0047] Step 4: Preparation of 6-ethoxy-1H-indene-1,2(3H)-dione-2-oxime
[0048] A solution of 6-ethoxy-1-indanone and isoamylnitrite (1.5 eq.) in ethyl acetate are cooled to approximately 0° C. and concentrated hydrochloric acid (1.1 acid equivalents) is added at a rate to keep the temperature below 40° C. After the addition is completed the slurry is stirred at 5-10° C. until analysis indicated that all of the starting material is consumed. The product is filtered and rinsed with cold ethyl acetate. The oxime product (5) can be easily purified by refluxing as a slurry in anhydrous ethanol, cooling filtering, and then washing the solid with more ethanol and then drying (m.p. 220° C. decomp.).
[0049] [0049] 1 H NMR (300 MHz, DMSO-d 6 ) δ1.32 (t, J=7.0 Hz, 3 H), 3.65 (s, 2 H), 4.06 (q, J=7.0 Hz, 2 H), 7.14 (d, J=2.5 Hz, 1 H), 7.27 (dd, J=2.6, 8.4 Hz, 1 H), 7.49 (d, J=8.4 Hz, 1 H), 12.57 (s, 1 H).
[0050] Step 5: Preparation of (±)-trans-2-amino-6-ethoxy-2,3-dihydro-1H-inden-1-ol
[0051] 6-Ethoxy-1H-indene-1,2(3H)-dione 2-oxime is slurried in absolute ethanol, and approximately 0.5 eq. 2N sodium hydroxide is added. Palladium on carbon is added, and the mixture is hydrogenated in a Parr shaker with an initial hydrogen pressure of 40 psi for several hours (depending upon the scale of the reaction and the catalyst loading). After analysis indicated that all of the starting material is consumed, the catalyst is filtered from the solution and then the solvent is removed under vacuum, and the residue is diluted with water and extracted with ethyl acetate several times. The ethyl acetate extracts are combined and concentrated under vacuum. Hexane is added and the resulting slurry is cooled to 0-15° C. and the solid product (6) is rinsed with cold ethyl acetate/hexane (1:1). The product is dried under vacuum.
[0052] An analytical sample is obtained by combined an aliquot of the product (6) with p-toluene sulfonic acid, and the resulting salt is crystallized from methanol/diethylether to afford a material of m.p. 172-173° C.
[0053] [0053] 1 H NMR (300 MHz, CDCl 3 ) δ1.394 (t, J=7.0 Hz, 3 H), 2.51 (dd, J=8.3, 14.9 Hz, 1 H), 3.13 (dd, J=7.3, 15.1 Hz, 1 H), 3.43 (q, J=7.2Hz, 1 H), 4.02 (q, J=7.0Hz, 2 H), 4.73 (d, J=6.7 Hz, 1 H), 6.78 (dd, J=2.2, 8.2 Hz, 1 H), 6.90 (d, J=2.2 Hz, 1 H), 7.06 (d, J=8.2Hz, 1H).
[0054] Step 6: Preparation of (1S, 2S)-trans-(−)-2-amino-6-ethoxy-2,3-dihydro-1H-inden-1-ol (R)-(−)-mandelate
[0055] (±)-trans-2-Amino-6-ethoxy-2,3-dihydro-1H-inden-1-ol in a mixture of methanol and tetrahydrofuran is added to a warm solution of a slight molar excess of (R)-(−)-mandelic acid in tetrahydrofuran, so that the result is a solution at about 60° C. in about 3-4 ml/g methanol and about 40-50 ml/g tetrahydrofuran. The desired mandelate salt (7) crystallizes from solution and is isolated by filtration and drying. ( m.p. 170-195° C. ). When treated with (R)-(−)-10-camphorsulfonic acid in methanol, the desired enantiomer (7) crystallizes from solution as the sulfonic acid salt complex ( m.p. 238-239° C. ). [α] 25 D=−8° (c=0.94, methanol).
[0056] Step 7: Preparation of (1S, 2S)-trans-2-(dipropylamino)-6-ethoxy-2,3-dihydro-1H-inden-1-ol
[0057] Aminoalcohol mandelate salt (7) is added to acetonitrile solvent with excess tribasic sodium phosphate and n-bromopropane and stirred until analysis indicates that starting material is completely converted to the dipropyl-substituted material (8). The preferred procedure is to heat the slurry at 60-70° C. for two—three days. The reaction is cooled, filtered, and the solids rinsed with methyl t-butyl ether. The solution is concentrated under vacuum and then more methyl t-butyl ether is added and the solution extracted with aqueous sodium hydroxide. The organic layer is washed with excess dilute aqueous hydrochloric acid and the aqueous hydrochloric acid extracts are combined and back-washed with methyl t-butyl ether and then made basic with concentrated aqueous sodium hydroxide. This aqueous solution is then washed with methyl t-butyl ether. The ether is removed under vacuum to obtain the dipropyl compound (8) as a solid. It is apparent to those skilled in the art that other similar alkylating reagents can be utilized in place of n-bromopropane, such as n-propyliodide, etc. Also, other bases can be utilized in place of the phosphate base, such as sodium carbonate, organic tertiary amine bases such as diisopropylethylamine, etc. The preferred procedure is to use n-bromopropane and tribasic sodium phosphate. Additionally, it is apparent to those skilled in the art that reductive amination procedures can also be used to perform this chemical transformation, including using propanal in the presence of a hydride transfer reducing reagent such as sodium triacetoxyborohydride, sodium cyanoborohydride, etc. Alternatively, the amine can be repetitively acylated to form the propionamide of the amine and then reduced to the amine with lithium aluminum hydride, diisobutylhydride, a borane reagent, etc. two times to introduce the required propyl groups. The preferred method to obtain 8 is to heat 7 with n-bromopropane in the presence of tribasic sodium phosphate. An analytical sample can be crystallized from ethyl acetate/hexane (m.p. 74-75° C.).
[0058] [0058] 1 H NMR (300 MHz, CDCl 3 ) δ0.90 (t, J=7.4 Hz, 6 H), 1.40 (t, J=7.0 Hz, 3 H) 1.52 (sextet, J=7.3 Hz, 4 H), 2.38 (br.s, 1 H), 2.47-2.64 (m, 4 H), 2.72 (dd, J=9.1, 15.1 Hz, 1 H), 2.89 (dd, J=7.8, 15.1 Hz, 1 H), 3.41 (dd, J=7.7, 16.6 Hz, 1 H), 4.02 (q, J=7.0 Hz, 2 H), 5.07 (d, J=7.4 Hz, 1 H), 6.78 (dd, J=2.4, 8.2 Hz, 1 H), 6.92 (d, J=2.2 Hz, 1 H), 7.06 (d, J=8.2 Hz, 1 H); [α] 25 D=34° (c=1.01, methanol).
[0059] Step 8: Preparation of (S)-5-ethoxy-2,3-dihydro-N,N-dipropyl-1H-inden-2-amine
[0060] (1S)-Trans-2-(dipropylamino)-6-ethoxy-2,3-dihydro-1H-inden-1-ol 8 is placed into a hydrogenation reactor with a catalytic amount of 5% palladium on carbon and acetic acid added as solvent. Acetic anhydride (excess over one equivalent—sufficient to completely convert all of 8 to the unisolated acetate intermediate) is also added and the mixture is hydrogenated at 40 p.s.i. while heating to 25°-80° C. (preferred temperature is 60°-70° C. When analysis indicated that 8 had been completely converted into 9 the mixture is cooled and filtered. The solvent is removed by heating under vacuum and the residue is extracted with methyl t-butyl ether and aqueous sodium hydroxide (added until the solution indicated a pH greater than 12). The aqueous layer is back extracted with more methyl t-butyl ether and the combined organic layers are washed with dilute aqueous sodium hydroxide solution. The methyl t-butyl ether solution is then extracted twice with 1 N aqueous hydrochloric acid, adding sufficient acid to wash all of the amine product into the aqueous layer). The aqueous acid layers are combined and washed with methyl t-butyl ether after which the aqueous layer is adjusted to a pH greater than 12 and then extracted with two portions of dichloromethane. The dichloromethane is washed with water and the solvent removed by heating under vacuum to afford 9. An analytical sample can be prepared as the p-toluenesulfonic acid salt from methanol/diethylether to afford crystals (m.p. 136-138° C.).
[0061] [0061] 1 H NMR (free base, 300 MHz, CDCl 3 ) δ0.88 (t, J=7.3 Hz, 6 H), 1.39 (t, J=7.0 Hz, 2 H), 1.49 (sextet, J=7.5 Hz, 4 H), 2.46-2.51 (m, 4 H), 2.75-3.01 (m, 4 H), 3.64 (quintet, J=8.2 Hz, 1 H), 3.99 (q, J=7.0 Hz, 2 H), 6.68 (d, J=8.2 Hz, 1 H), 6.73 (s, 1 H), 7.05 (d, J=8.1 Hz, 1 H); [α] 25 D=11°(c=0.82, methanol).
[0062] Step 9: Preparation of (R)-5-bromo-6-ethoxy-2,3-dihydro-N,N-dipropyl-1H-inden-2-amine
[0063] Pyridinium perbromide 1-1.5 equivalents (preferably 1.3-1.4 equivalents) is added to dichloromethane solvent and cooled between −60° C. and 25° C. (−15° C. to 25° C. is the preferred temperature range). A−15° C. solution of (S)-6-ethoxy-2,3-dihydro-N,N-dipropyl-1H-inden-2-amine (9) and trifluoroacetic acid (1-5 equivalents with 3 equivalents being preferred) dissolved in dichloromethane is added. After stirring for several hours the reaction is warmed to 0° C. When analysis indicated that all of 9 had been consumed, the reaction is quenched with a reducing agent such as aqueous sodium bisulfite. Aqueous sodium hydroxide is then added to make the pH greater than 12 and most of the dichloromethane and pyridine are removed by heating under vacuum. The residue is extracted several times with methyl t-butyl ether, the organic layers are combined, stirred with magnesium sulfate to dry, filtered, and the solvent removed by heating under vacuum to afford 10 in crude form. If necessary, this is crystallized from methanol/methyl t-butyl ether as the hydrochloride salt to afford purified 10 as its hydrochloride salt (m.p. of an analytical sample 202-204° C.).
[0064] It will be apparent to one skilled in the art that other methods of brominating 9 exist, such as direct treatment with bromine, N-bromosuccinimide, dibromohydantoin, etc. Other acid catalysts can also be utilized, such as acetic acid and other low molecular weight carboxylic acids, mineral acids, organic sulfonic acids, etc. Trifluoroacetic acid is the preferred acid catalyst.
[0065] [0065] 1 H NMR (free base, 300 MHz, CDCl 3 ) δ0.86 (t, J=7.4 Hz, 6 H), 1.41-1.55 (m, 7 H), 2.43-2.49 (m, 4 H), 2.76-2.99 (m, 4 H), 3.57 (quintet, J=8.2 Hz, 1 H), 4.05 (q, J=7.0 Hz, 2 H), 6.73 (s, 1 H), 7.31 (s, 1 H); [α] 25 D=5°(c=1.01, methanol).
[0066] Step 10: Preparation of (S)-(+)-(dipropylamino)-6-ethoxy-2,3-dihydro-1H-indene-5-carboxamide
[0067] Compound 10 (as its hydrochloride salt) is combined with dimethylformamide with a catalytic amount of palladium acetate (0.008-0.08 equiv., with 0.01-0.04 equiv. being preferred) and 1,3-bis(diphenylphosphino)propane (approximately twice the number of molar equivalents as the palladium catalyst), potassium carbonate, and hexamethyldisilylazane. The reaction is heated to 70°-120° C. (100° C. being preferred) under an atmosphere of carbon monoxide until analysis indicated that all of 10 had been consumed. The reaction is cooled, diluted with methyl t-butyl ether (MTBE) and water, and filtered to remove solids. The two-phase mixture is made basic and product is extracted into MTBE. The extracts are washed with dilute base, then water. The solution is placed under vacuum and heated to remove volatile reagents and solvents. The residue is slurried with aqueous hydrochloric acid and filtered. The filtrate is extracted with MTBE. The aqueous phase is made basic with aqueous sodium hydroxide, and the product is extracted into methyl t-butyl ether. The extracts are washed again with water and then dried by distillation. The resulting MTBE solution is treated with magnesium silicate adsorbent, which is removed by filtration. The methyl t-butyl ether filtrate is concentrated and heptane added at approximately 50° C. followed by gradual cooling to induce the crystallization of 11 which is filtered and dried. It is readily apparent to one skilled in the art that a variety of palladium catalysts (PdCl 2 , Pd n (dba) m , etc.) and associated ligands (triphenylphosphine, tri-ortho-tolulyphosphine, etc) can be utilized in varying catalytic quantities.
[0068] Additionally, 10 in its free base form can be dissolved in an etheral solvent such as tetrahydrofuran and cooled to −20° to −78° C. (preferably −25° to −50° C.) and a solution of an alkyllithium such as t-butyllithium added. Trimethylsilylisocyanate (see Parker, K. A.; Gibbons, E. G. “A Direct Synthesis of Primary Amides from Grignard Reagents”, Tetrahed. Lett. 1975, 981-984) is then added and the solution is allowed to slowly warm to 10° C. and then quenched by the addition of water. Methyl t-butyl ether is added and the mixture is extracted. The organic layer is dried with magnesium sulfate and the solvent removed to afford 11 which is purified as the hydrochloride salt by treating with a methanol solution of hydrochloric acid, concentrating under vacuum, and recrystallizing the solid from ethyl acetate. The crystals are converted to the freebase by treatment with aqueous sodium hydroxide, extraction into ethyl acetate, drying with magnesium sulfate, and removal of the solvent under vacuum (m.p. 100-101° C.).
[0069] [0069] 1 H NMR (CDCl 3 ) δ7.99 (s, 1 H), 7.87 (bs, 1 H), 6.78 (s, 1 H), 6.12 (bs, 1 H), 4.17-4.11 (q, J=7.0 Hz, 2 H), 3.72-3.61 (m, 1 H), 3.06-2.78 (m, 4 H), 2.48-2.43 (m, 4 H), 1.54-1.41 (m, 7 H), 0.87 (t, J=7.3 Hz, 6 H; [α] 25 D=+4.94°(c=0.842, MeOH).
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The present invention relates to (2S)-enantiomers of 2-aminoindan derivatives of formula I:
and a novel process for the preparation of them.
| 2
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PRIORITY APPLICATION
[0001] This is a continuation of U.S. patent application Ser. No. 13/547,474, filed on Jul. 12, 2012, which is a continuation of U.S. patent application Ser. No. 10/744,555, filed Dec. 23, 2003, now U.S. Pat. No. 8,223,632, all of which are hereby incorporated herein by reference in their entireties.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] The present application is related to U.S. patent application Ser. No. 10/348,077, entitled “Method and System for Obtaining Logical Performance Data for a Circuit in a Data Network,” filed on Jan. 21, 2003, and U.S. patent application Ser. No. 10/348,592, entitled “Method and System for Provisioning and Maintaining a Circuit in a Data Network,” filed on Jan. 21, 2003. This application is also related to and filed concurrently with U.S. patent application Ser. No. 10/745,117, entitled “Method And System For Providing A Failover Circuit For Rerouting Logical Circuit Data In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/744,281, entitled “Method And System For Utilizing A Logical Failover Circuit For Rerouting Data Between Data Networks,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/745,047, entitled “Method And System For Automatically Renaming Logical Circuit Identifiers For Rerouted Logical Circuits In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/745,170, entitled “Method And System For Automatically Identifying A Logical Circuit Failure In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/744,921, entitled “Method and System For Automatically Rerouting Logical Circuit Data In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/745,168, entitled “Method And System For Automatically Rerouting Logical Circuit Data In A Virtual Private Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/745,116, entitled “Method And System For Automatically Rerouting Data From An Overbalanced Logical Circuit In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/744,555, entitled “Method And System For Real Time Simultaneous Monitoring Of Logical Circuits In A Data Network,” filed on Dec. 23, 2003. All of the above-referenced applications are assigned to the same assignee as the present application and are expressly incorporated herein by reference.
TECHNICAL FIELD
[0003] The present disclosure relates to the routing of data using logical circuits in a data network. More particularly, the present disclosure is related to rerouting data in a data network.
BACKGROUND
[0004] Data networks contain various network devices, such as switches, for sending and receiving data between two locations. For example, frame relay and Asynchronous Transfer Mode (“ATM”) networks contain interconnected network devices that allow data packets or cells to be channeled over a circuit through the network from a host device to a remote device. For a given network circuit, the data from a host device is delivered to the network through a physical circuit such as a T1 line that links to a switch of the network. The remote device that communicates with the host through the network also has a physical circuit to a switch of the network. A network circuit also includes a logical circuit which includes a variable communication path for data between the switches associated with the host and the remote device. Logical circuits may be provisioned with certain quality of service (“QoS”) parameters or traffic descriptors which describe the level of priority given to data communicated through a data network. For example, an ATM circuit provisioned for constant bit rate (“CBR”) service carries higher priority data (such as voice traffic) than unspecified bit rate (“UBR”) service. CBR service assures that high priority data, such as voice traffic, which is sensitive to delay, is communicated at a guaranteed data rate for quality service. Conversely, UBR service assures no quality guarantees making data communicated at this level highly susceptible to delay and network congestion.
[0005] In large-scale networks, the host and remote end devices of a network circuit may be connected across different local access and transport areas (“LATAs”) which may in turn be connected to one or more Inter-Exchange Carriers (“IEC”) for transporting data between the LATAs. These connections are made through physical trunk circuits utilizing fixed logical connections known as Network-to-Network Interfaces (“NNIs”).
[0006] Periodically, failures may occur to the trunk circuits or the NNIs of network circuits in large-scale networks causing lost data. Currently, such failures are handled by dispatching technicians on each end of the network circuit (i.e., in each LATA) in response to a reported failure to manually repair the logical and physical connections making up the network circuit. Some modern data networks also include redundant physical connections for rerouting data from failed physical connections in a network circuit while the failed physical connections are being repaired. These “self-healing” networks however, do not account for existing QoS parameters for failed network circuits, resulting in the data being communicated at the lowest available quality of service (e.g., UBR) over the redundant physical connections. As a result, the communication of high priority data packets or cells from the failed circuit may be delayed or dropped entirely.
[0007] It is with respect to these considerations and others that the present invention has been made.
SUMMARY
[0008] In accordance with the present disclosure, the above and other problems are solved by a method and system for prioritized rerouting of logical circuit data in a data network. When a logical circuit failure is detected, the data in the logical circuit may be rerouted to a logical failover circuit at the same quality of service provisioned for the failed logical circuit.
[0009] According to the method, logical circuit failure is identified in the data network. Following the identification of the logical circuit failure, a quality of service parameter for the communication of data in the failed logical circuit is determined. Then a logical failover circuit comprising an alternate communication path for communicating the data in the failed logical circuit is identified. Next, a quality of service parameter for the communication of data in the logical failover circuit is determined. If the quality of service parameter for the failed logical circuit is equal to the quality of service parameter for the logical failover circuit, then the data from the failed logical circuit is rerouted to the logical failover circuit.
[0010] The method may further include rerouting the data to the logical failover circuit when the quality of service parameter for the failover circuit is indicative of a lower level of quality if authorization is received for the reroute. The quality of service parameter may include a traffic descriptor for logical circuit data. The quality of service parameter may be a variable frame relay (“VFR”) real time parameter, a VFR non-real time parameter, a constant bit rate (“CBR”) parameter, a variable bit rate (“VBR”) parameter, or an unspecified bit rate (“UBR”) parameter.
[0011] The logical failover circuit may include a dedicated failover logical connection in a failover data network. The logical circuit and the logical failover circuit may be identified by logical circuit identifiers. The logical circuit identifiers may be data link connection identifiers (“DLCIs”) or virtual path/virtual circuit identifiers (“VPI/VCIs”). The dedicated failover logical connection may be a network-to-network interface (“NNI”). The logical failover circuit may be either a permanent virtual circuit (“PVC”) or a switched virtual circuit (“SVC”). The data network may be either frame relay network or an asynchronous transfer mode (“ATM”) network.
[0012] In accordance with other aspects, the present disclosure relates to a system for prioritized rerouting of logical circuit data in a data network. The system includes a network device for communicating status information for a logical circuit in the data network. The logical circuit includes a communication path for communicating data. The system also includes a logical element module, in communication with the network device, for receiving the status information for the logical circuit in the data network. The system further includes a network management module, in communication with the logical element module, for identifying a failed logical circuit in the data network, determining a quality of service parameter for the communication of data in the failed logical circuit, identifying a logical failover circuit including an alternate communication path for communicating the data in the failed logical circuit, and determining a quality of service parameter for the communication of data in the logical failover circuit. If the quality of service parameter for the failed logical circuit is equal to the quality of service parameter for the logical failover circuit, then the data is rerouted to the logical failover circuit. If the quality of service parameter for the failed logical circuit is not equal to the quality of service parameter for the logical failover circuit, then authorization is obtained prior to rerouting the data to the logical failover circuit.
[0013] In accordance with still other aspects, the present disclosure relates to a system for prioritized rerouting of logical circuit data in a data network. The system includes a network device for communicating status information for a logical circuit in the data network. The logical circuit includes a communication path for communicating data. The system also includes a logical element module, in communication with the network device, for receiving the status information for the logical circuit in the data network. The system further includes a network management module, in communication with the logical element module, for identifying a failed logical circuit in the data network, determining a quality of service parameter for the communication of data in the failed logical circuit, and provisioning a logical failover circuit comprising an alternate communication path for communicating the data in the failed logical circuit. The logical failover circuit is provisioned having a quality of service parameter equal to the quality of service parameter for the failed logical circuit. The network management module then reroutes the data from the failed logical circuit to the provisioned logical failover circuit.
[0014] These and various other features as well as advantages will be apparent from a reading of the following detailed description and a review of the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates a data network according to an embodiment of the disclosure.
[0016] FIG. 2 illustrates a local access and transport area (“LATA”) in the data network of FIG. 1 , according to an embodiment of the disclosure.
[0017] FIG. 3 illustrates a network management system which may be utilized for prioritized rerouting of logical circuit data in the data network of FIG. 1 , according to an embodiment of the disclosure.
[0018] FIG. 4 illustrates a failover data network for rerouting logical circuit data, according to an embodiment of the disclosure.
[0019] FIG. 5 illustrates a flowchart describing logical operations for prioritized rerouting of logical circuit data in a data network of FIG. 1 , according to an embodiment of the disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Embodiments of the present disclosure provide for a method and system for prioritized rerouting of logical circuit data in a data network. When a logical circuit failure is detected, the data in the logical circuit may be rerouted to a logical failover circuit at the same quality of service provisioned for the failed logical circuit. In the following detailed description, references are made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments or examples. Referring now to the drawings, in which like numerals represent like elements through the several figures, aspects of the present disclosure and the exemplary operating environment will be described.
[0021] Embodiments of the present disclosure may be generally employed in a data network 2 as shown in FIG. 1 . The data network 2 includes local access and transport areas (“LATAs”) 5 and 15 which are connected by an Inter-Exchange Carrier (“IEC”) 10 . It should be understood that the LATAs 5 and 15 may be data networks operated by a commonly owned Local Exchange Carrier (“LEC”). It should be further understood that the IEC 10 may include one or more data networks which may be operated by a commonly owned IEC. It will be appreciated by those skilled in the art that the data network 2 may be a frame relay network, asynchronous transfer mode (“ATM”) network, or any other network capable of communicating data conforming to Layers 2-4 of the Open Systems Interconnection (“OSI”) model developed by the International Standards Organization, incorporated herein by reference. It will be appreciated that these networks may include, but are not limited to, communications protocols conforming to the Multiprotocol Label Switching Standard (“MPLS”) networks and the Transmission Control Protocol/Internet Protocol (“TCP/IP”), which are known to those skilled in the art.
[0022] The data network 2 includes a network circuit which channels data between a host device 112 and a remote device 114 through the LATA 5 , the IEC 10 , and the LATA 15 . It will be appreciated by those skilled in the art that the host and remote devices 112 and 114 may be local area network (“LAN”) routers, LAN bridges, hosts, front end processors, Frame Relay Access Devices (“FRADs”), or any other device with a frame relay, ATM, or network interface. It will be further appreciated that in the data network 2 , the LATAs 5 and 15 and the IEC 10 may include network elements (not shown) which support interworking to enable communications between host and remote devices supporting dissimilar protocols. Network elements in a data network supporting interworking may translate frame relay data packets or frames sent from a host FRAD to ATM data packets or cells so that a host device may communicate with a remote device having an ATM interface. The LATAs 5 and 15 and the IEC 10 may further include one or more interconnected network elements, such as switches (not shown), for transmitting data. An illustrative LEC data network will be discussed in greater detail in the description of FIG. 2 below.
[0023] The network circuit between the host device 112 and the remote device 114 in the data network 2 includes a physical circuit and a logical circuit. As used in the foregoing description and the appended claims, a physical circuit is defined as the physical path that connects the end point of a network circuit to a network device. For example, the physical circuit of the network circuit between the host device 112 and the remote device 114 includes the physical connection 121 between the host device 112 and the LATA 5 , the physical connection 106 between the LATA 5 and the IEC 10 , the physical connection 108 between the IEC 10 and the LATA 15 , and the physical connection 123 between the LATA 15 and the remote device 114 . Routers and switches within the LATAs 5 and 15 and the IEC 10 carry the physical signal between the host and remote end devices 112 and 114 through the physical circuit.
[0024] It should be understood that the host and remote devices may be connected to the physical circuit described above using user-to-network interfaces (“UNIs”). As is known to those skilled in the art, an UNI is the physical demarcation point between a user device (e.g, a host device) and a public data network. It will further be understood by those skilled in the art that the physical connections 106 and 108 may include trunk circuits for carrying the data between the LATAs 5 and 15 and the IEC 10 . It will be further understood by those skilled in the art that the connections 121 and 123 may be any of various physical communications media for communicating data such as a 56 Kbps line or a T1 line carried over a four-wire shielded cable or over a fiber optic cable.
[0025] As used in the foregoing description and the appended claims, a logical circuit is defined as a portion of the network circuit wherein data is sent over variable communication data paths or logical connections established between the first and last network devices within a LATA or IEC network and over fixed communication data paths or logical connections between LATAs (or between IECs). Thus, no matter what path the data takes within each LATA or IEC, the beginning and end of each logical connection between networks will not change. For example, the logical circuit of the network circuit in the data network 2 may include a variable communication path within the LATA 5 and a fixed communication path (i.e., the logical connection 102 ) between the LATA 5 and the IEC 10 . It will be understood by those skilled in the art that the logical connections 102 and 104 in the data network 2 may include network-to-network interfaces (“NNIs”) between the last sending switch in a LATA and the first receiving switch in an IEC. It should be understood that in data networks supporting interworking (i.e., utilizing both frame relay and ATM devices), data may be communicated over frame relay circuits over the UNI connections between the host or remote device and the LATA (or IEC) data network, and over ATM circuits over the NNI connections within the LATA (or IEC) data network.
[0026] As is known to those skilled in the art, each logical circuit in a data network may be identified by a unique logical identifier. In frame relay networks, the logical identifier is called a Data Link Connection Identifier (“DLCI”) while in ATM networks the logical identifier is called a Virtual Path Identifier/Virtual Circuit Identifier (“VPI/VCI”). In frame relay networks, the DLCI is a 10-bit address field contained in the header of each data frame and contains identifying information for the logical circuit as well as information relating to the destination of the data in the frame, quality of service (“QoS”) parameters, and other service parameters for handling network congestion. For example, in the data network 2 implemented as a frame relay network, the designation DLCI 100 may be used to identify the logical circuit between the host device 112 and the remote device 114 . It will be appreciated that in data networks in which logical circuit data is communicated through more than one carrier (e.g., an LEC and an IEC) the DLCI designation for the logical circuit may change in a specific carrier's network. For example, in the data network 2 , the designation DLCI 100 may identify the logical circuit in the LATA 5 and LATA 15 but the designation DLCI 800 may identify the logical circuit in the IEC 10 .
[0027] Illustrative QoS parameters which may be included in the DLCI include a Variable Frame Rate (“VFR”) real time parameter and a VFR non-real time parameter. As is known to those skilled in the art, VFR real time is a variable data rate for frame relay data frames communicated over a logical circuit. Typically, VFR real-time circuits are able to tolerate small variations in the transmission rate of data (i.e., delay) and small losses of frames. Typical applications for VFR real time circuits may include, but are not limited to, voice and some types of interactive video. VFR non-real time circuits also communicate data frames at a variable data rate but are able to tolerate higher variations in the transmission rate and thus more delay as these circuits are typically “bursty” (i.e., data is transmitted in short, uneven spurts) in nature. Typical applications for VFR non-real time circuits include, but are limited to, inter-LAN communications and Internet traffic.
[0028] Illustrative service parameters which may be included in the DLCI include a Committed Information Rate (“CIR”) parameter and a Committed Burst Size (“Be”) parameter. As is known to those skilled in the art, the CIR represents the average capacity of the logical circuit and the Be represents the maximum amount of data that may be transmitted. It will be appreciated that the logical circuit may be provisioned such that when the CIR or the Be is exceeded, the receiving switch in the data network will discard the frame. It should be understood that the logical circuit parameters are not limited to CR and Be and that other parameters known to those skilled in the art may also be provisioned, including, but not limited to, Burst Excess Size (“Be”) and Committed Rate Measurement Interval (“Tc”).
[0029] In ATM networks, the VPI/VCI is an address field contained in the header of each ATM data cell and contains identifying information for the logical circuit as well as information specifying a data cell's destination, QoS parameters, and specific bits which may indicate, for example, the existence of congestion in the network and a threshold for discarding cells. Illustrative QoS parameters which may be included in the VPI/VCI include a Committed Bit Rate (“CBR”) parameter, a Variable Bit Rate (“VBR”) parameter, and an Unspecified Bit Rate (“UBR”) parameter. As is known to those skilled in the art, CBR defines a constant data rate for ATM cells communicated over a logical circuit. Typically, CBR circuits are given the highest priority in a data network and are very intolerant to delay. Typical applications for CBR circuits may include, but are not limited to, video conferencing, voice, television and video-on demand. VBR circuits communicate ATM cells at a variable data rate and are able to tolerate varying degrees of delay. Similar to frame relay variable service parameters, VBR circuits may be further subdivided into VBR real time and VBR non-real time. VBR non-real time circuits are able to tolerate more delay. Typical applications for ATM VBR circuits may include the same applications as frame relay VFR circuits. UBR circuits communicate ATM cells at an unspecified bit rate and are extremely tolerant to delay. UBR circuits are typically reserved for non-time sensitive applications such as file transfer, email, and message and image retrieval.
[0030] It should be understood that the logical circuit in the data network 2 may be a permanent virtual circuit (“PVC”) available to the network at all times or a temporary or a switched virtual circuit (“SVC”) available to the network only as long as data is being transmitted. It should be understood that the data network 2 may further include additional switches or other interconnected network elements (not shown) creating multiple paths within each LATA and IEC for defining each PVC or SVC in the data network. It will be appreciated that the data communicated over the logical connections 102 and 104 may be physically carried by the physical connections 106 and 108 .
[0031] The data network 2 may also include a failover network 17 for rerouting logical circuit data, according to an embodiment of the disclosure. The failover network 17 may include a network failover circuit including physical connections 134 and 144 and logical connections 122 and 132 for rerouting logical circuit data in the event of a failure in the network circuit between the host device 112 and the remote device 114 . The failover network 17 will be described in greater detail in the description of FIG. 4 below. The data network 2 may also include a network management system 175 in communication with the LATA 5 , the LATA 15 , and the failover network 17 . The network management system 175 may be utilized to obtain status information for the logical and physical circuit between the host device, 112 and the remote device 114 . The network management system 175 may also be utilized for rerouting logical data in the data network 2 between the host device 112 and the remote device 114 . The network management system 175 will be discussed in greater detail in the description of FIG. 3 below.
[0032] FIG. 2 illustrates the LATA 5 in the data network 2 described in FIG. 1 above, according to an embodiment of the present disclosure. As shown in FIG. 2 , the LATA 5 includes interconnected network devices such as switches 186 , 187 , and 188 . It will be appreciated that the data network 2 may also contain other interconnected network devices and elements (not shown) such as digital access and cross connect switches (“DACS”), channel service units (“CSUs”), and data service units (“DSUs”). As discussed above in the description of FIG. 1 , the connection data paths of a logical circuit within a data network may vary between the first and last network devices in a data network. For example, as shown in FIG. 2 , the logical circuit in the LATA 5 may include the communication path 185 between the switches 186 and 188 or the communication path 184 between the switches 186 , 187 , and 188 . As discussed above, it should be understood that the actual path taken by data through the LATA 5 is not fixed and may vary from time to time, such as when automatic rerouting takes place.
[0033] It will be appreciated that the switches 186 , 187 , and 188 may include a signaling mechanism for monitoring and signaling the status of the logical circuit in the data network 2 . Each time a change in the status of the logical circuit is detected (e.g., a receiving switch begins dropping frames), the switch generates an alarm or “trap” which may then be communicated to a management station, such as a logical element module (described in detail in the description of FIG. 3 below), in the network management system 175 . The trap may include, for example, status information indicating network congestion.
[0034] In one embodiment, the signaling mechanism may be in accord with a Local Management Interface (“LMI”) specification, which provides for the sending and receiving of “status inquiries” between a data network and a host or remote device. The LMI specification includes obtaining status information through the use of special management frames (in frame relay networks) or cells (in ATM networks). In frame relay networks, for example, the special management frames monitor the status of logical connections and provide information regarding the health of the network. In the data network 2 , the host and remote devices 112 and 114 receive status information from the switches in the individual LATAs they are connected to in response to a status request sent in a special management frame or cell. The LMI status information may include, for example, whether or not the logical circuit is congested or whether or not the logical circuit has failed. It should be understood that the parameters and the signaling mechanism discussed above are optional and that other parameters and mechanisms may also be utilized to obtain connection status information for a logical circuit.
[0035] FIG. 3 illustrates the network management system 175 which may be utilized for prioritized rerouting of logical circuit data in the data network of FIG. 1 , according to an embodiment of the disclosure. The network management system 175 includes a service order system 160 , a network database 170 , a logical element module 153 , a physical element module 155 , a network management module 176 , and a test module 180 . The service order system 160 is utilized in the data network 2 for receiving service orders for provisioning network circuits. The service order includes information defining the transmission characteristics or QoS parameters for the logical circuit portion of the network circuit. The service order also contains the access speed, CIR, burst rates, and excess burst rates. The service order system 160 communicates the service order information to a network database 170 over management trunk 172 . The network database 170 assigns and stores the parameters for the physical circuit portion of the network circuit such as a port number on the switch 186 for transmitting data over the physical connection 121 to and from the host device 112 .
[0036] The network database 170 may also be in communication with an operations support system (not shown) for assigning physical equipment to the network circuit and for maintaining an inventory of the physical assignments for the network circuit. An illustrative operations support system is “TIRKS”® (Trunks Integrated Records Keeping System) marketed by TELECORDIA™ TECHNOLOGIES, Inc. of Morristown, N.J. The network database 170 may also be in communication with a Work Force Administration and Control system (“WFA/C”) (not shown) used to assign resources (i.e., technicians) to work on installing the physical circuit.
[0037] The network management system 175 also includes the logical element module 153 which is in communication with the switches in the data network 2 through management trunks 183 . The logical element module 153 runs a network management application program to monitor the operation of logical circuits which includes receiving trap data generated by the switches which indicate the status of logical connections. The trap data may be stored in the logical element module 153 for later analysis and review. The logical element module 153 is also in communication with the network database 170 via management trunks 172 for accessing information regarding logical circuits such as the logical identifier data. The logical identifier data may include, for example, the DLCI or VPI/VCI header information for each data frame or cell in the logical circuit including the circuit's destination and QoS parameters. The logical element module 153 may consist of terminals (not shown) that display a map-based graphical user interface (“GUI”) of the logical connections in the data network. An illustrative logical element module is the NAVISCORE™ system marketed by LUCENT TECHNOLOGIES, Inc. of Murray Hill, N.J.
[0038] The network management system 175 further includes the physical element module 155 in communication with the physical connections of the network circuit via management trunks (not shown). The physical element module 155 runs a network management application program to monitor the operation and retrieve data regarding the operation of the physical circuit. The physical element module 155 is also in communication with the network database 170 via management trunks 172 for accessing information regarding physical circuits, such as line speed. Similar to the logical element module 153 , the physical logical element module 155 may also consist of terminals (not shown) that display a map-based GUI of the physical connections in the LATA 5 . An illustrative physical element module is the Integrated Testing and Analysis System (“INTAS”), marketed by TELECORDIA™ TECHNOLOGIES, Inc. of Morristown, N.J., which provides flow-through testing and analysis of telephony, services.
[0039] The physical element module 155 troubleshoots the physical connections for a physical circuit by communicating with test module 180 , which interfaces with the physical connections via test access point 156 . The test module 180 obtains the status of the physical circuit by transmitting “clean” test signals to test access point 156 (shown in FIG. 2 ) which “loops back” the signals for detection by the test module 180 . It should be understood that there may be multiple test access points on each of the physical connections for the physical circuit.
[0040] The network management system 175 further includes the network management module 176 which is in communication with the service order system 160 , the network database 170 , the logical element module 153 , and the physical element module 155 through communications channels 172 . It should be understood that in one embodiment, the network management system 175 may also be in communication with the LATA 15 , the IEC 10 , and the fail over network 17 . The communications channels 172 may be on a LAN. The network management module 176 may consist of terminals (not shown), which may be part of a general-purpose computer system that displays a map-based GUI of the logical connections in data networks. The network management module 176 may communicate with the logical element module 153 and the physical element module 155 using a Common Object Request Broker Architecture (“CORBA”). As is known to those skilled in the art, CORBA is an open, vendor-independent architecture and infrastructure which allows different computer applications to work together over one or more networks using a basic set of commands and responses. The network management module 176 may also serve as an interface for implementing logical operations to provision and maintain network circuits. The logical operations may be implemented as machine instructions stored locally or as instructions retrieved from the logical and physical element modules 153 and 155 . An illustrative method detailing the provisioning and maintenance of network circuits in a data network is presented in U.S. patent application Ser. No. 10/348,592, entitled “Method And System For Provisioning And Maintaining A Circuit In A Data Network,” filed on Jan. 23, 2003, and assigned to the same assignee as this application, which is expressly incorporated herein by reference. An illustrative network management module is the Broadband Network Management System® (“BBNMS”) marketed by TELECORDIA™ TECHNOLOGIES, Inc. of Morristown, N.J.
[0041] FIG. 4 illustrates an illustrative failover data network for rerouting logical circuit data, according to one embodiment of the present disclosure. As shown in FIG. 4 , the failover network 17 includes an IEC 20 , a LATA 25 , and an IEC 30 . The failover network further includes a network failover circuit which includes a physical failover circuit and a logical failover circuit. The physical failover circuit includes the physical connection 134 between the LATA 5 (shown in FIG. 1 ) and the IEC 20 , the physical connection 136 between the IEC 20 and the LATA 25 , the physical connection 138 between the LATA 25 and the IEC 30 , and the physical connection 144 between the IEC 30 and the LATA 15 (shown in FIG. 1 ). Similarly, the logical failover circuit may include the logical connection 122 between the LATA 5 (shown in FIG. 1 ) and the IEC 20 , the logical connection 124 between the IEC 20 and the LATA 25 , the logical connection 126 between the LATA 25 and the IEC 30 , and the logical connection 132 between the IEC 30 and the LATA 15 (shown in FIG. 1 ). It should be understood that in one embodiment, the network failover circuit illustrated in the failover network 17 may include a dedicated physical circuit and a dedicated logical circuit provisioned by a network service provider serving the LATAs 5 , 15 , and 25 and the IECs 20 and 30 , for rerouting logical data from a failed logical circuit.
[0042] FIG. 5 illustrates a flowchart describing logical operations 500 for prioritized rerouting of logical circuit data in the data network 2 of FIG. 1 , according to an embodiment of the disclosure. It will be appreciated that the logical operations 500 may be initiated when a customer report of a network circuit failure is received in the data network 2 . For example, a customer at the remote device 114 may determine that the remote device 114 is dropping frames or cells sent from the host device 112 (e.g., by reviewing LMI status information in the host device). After receiving the customer report, the network service provider providing the network circuit may open a trouble ticket in the service order system 160 to troubleshoot the logical circuit.
[0043] The logical operations 500 begin at operation 505 where the network management module 176 identifies a failed logical circuit in the data network 2 . It will be appreciated that a logical circuit failure may be based on status information received in communications with the logical element module 153 to request trap data generated by one or more switches in the data network 2 . The trap data indicates the status of one or more logical connections making up the logical circuit. For example, in the data network 2 shown in FIG. 1 , the “X” marking the logical connections 102 and 104 indicates that both connections are “down beyond” the logical connections in the LATA data networks 5 and 15 . It will be appreciated that in this example, the logical circuit failure lies in the IEC data network 10 . An illustrative method detailing the identification of logical circuit failures in a data network is presented in co-pending U.S. patent application Ser. No. 10/745,170, entitled “Method And System For Automatically Identifying A Logical Circuit Failure In A Data Network,” filed on Dec. 23, 2003, and assigned to the same assignee as this application, which is expressly incorporated herein by reference.
[0044] After identifying a failed logical circuit at operation 505 , the logical operations 500 continue at operation 510 where the network management module 176 determines the QoS parameter for the communication of data in the failed logical circuit. As discussed above in the description of FIG. 1 , the QoS parameters for a logical circuit are contained within the DLCI (for frame relay circuits) or the VPI/VCI (for ATM circuits). The QoS parameters for logical circuits may also be stored in the network database 170 after the circuits are provisioned in the data network. Thus, in one embodiment of the present disclosure, the network management module 176 may determine the logical identifier for the failed logical circuit from the trap data received from the logical element module 153 and then access the database 170 to determine the QoS parameter for the circuit. The logical operations then continue from operation 510 to operation 515 .
[0045] At operation 515 , the network management module 176 identifies a logical failover circuit for communicating failed logical circuit data over an alternate communication in the data network 2 . For example, if as shown in FIG. 1 , it is determined that the failure in the logical circuit in the data network 2 has been isolated to the IEC data network 10 , a logical failover circuit in the failover network 17 may be automatically selected to reroute the logical data such that it bypasses the IEC data network 10 . For example, the logical failover circuit may be selected including the logical connections 122 , 124 , 126 , and 132 (as shown in FIG. 4 ) to reroute the logical data from the host device 112 , through the LATA 5 , the IEC 20 , the LATA 25 , the IEC 30 , the LATA 15 , and finally to the remote device 114 .
[0046] It should be understood that the network management module 176 may select the logical failover circuit by identifying a logical connection or NNI in the overbalanced logical circuit. Information related to each logical connection in a logical circuit may be stored in the database 170 including the first and second ends of the logical circuit to which the logical connection belongs. Once the ends of a logical circuit are determined by accessing the database 170 , the network management module 176 may select a logical failover circuit having a communication path including the first and second ends of the overbalanced logical circuit for rerouting data.
[0047] It will be appreciated that in one embodiment, the logical failover circuit selected may be a dedicated circuit which is only utilized for rerouting logical data from the failed logical circuit (i.e., the failover circuit does not normally communicate data traffic). In this embodiment, the logical failover circuit may be provisioned with the same QoS parameter as the logical circuit to which it is assigned. In another embodiment, the logical failover circuit may be an existing logical circuit which is normally utilized for communicating data traffic in the data network 2 . In this embodiment, the selection of the logical failover circuit may also include determining whether one or more logical connections in the logical circuit are currently communicating data traffic or are currently unused. If currently unused, the logical connections may be selected for rerouting logical data. For example, a technician at the logical element module 153 or the network management module 176 may utilize a map-based GUI displaying the logical connections in the LATA data networks 5 and 15 and their status. A dedicated logical failover circuit (or a currently unused logical circuit with available logical connections) may then be selected as a logical failover circuit for communicating logical data from a failed logical circuit. The logical operations 500 then continue from operation 515 to operation 520 .
[0048] At operation 520 , the network management module determines the QoS parameter for the previously identified logical failover circuit. It will be appreciated that the identification of the QoS parameter for the logical failover circuit may be made by identifying the logical circuit ID for the logical failover circuit and then accessing the network database 170 to retrieve the QoS parameter for the circuit. The logical operations 500 then continue from operation 520 to operation 525 .
[0049] At operation 525 the network management module 176 compares the QoS parameters for the failed logical circuit and the logical failover circuit to determine if they are the same. If the QoS parameters are the same, the logical operations continue to operation 535 where the failed logical circuit data is rerouted over the logical failover circuit. An illustrative method detailing the rerouting of failed logical circuits in a data network is presented in co-pending U.S. patent application Ser. No. 10/744,921, entitled “Method And System For Automatically Rerouting Logical Circuit Data In A Data Network,” filed on Dec. 23, 2003, and assigned to the same assignee as this application, which is expressly incorporated herein by reference.
[0050] For example, if the network management module 176 determines that the QoS for the failed logical circuit and the logical failover circuit is CBR, then the failed logical circuit data is rerouted over the logical failover circuit while maintaining the same quality of service. It will be appreciated that in data networks supporting interworking (i.e., both frame relay and ATM devices), the network management module 176 may be configured to reroute logical circuit data based on similar QoS parameters from each protocol. For example, if the failed logical circuit has a frame relay QoS parameter of VFR real time, the network management module 176 may reroute the data to an ATM logical failover circuit having a QoS parameter of VBR real time, since these quality of service parameters are defined to tolerate only small variations in transmission rates. Similarly, a failed logical circuit having an ATM QoS parameter of UBR may be rerouted over a frame relay logical failover circuit having a QoS of VFR non-real time since both of these parameters are tolerant of delay and variable transmission rates.
[0051] If, however, at operation 525 , the network management module 176 determines that the QoS parameters for the failed logical circuit and the logical failover circuit are not the same, then the logical operations continue from operation 525 to operation 530 where the network management module 176 obtains authorization to reroute the logical circuit data. Once authorization is received, the logical operations 530 then continue to operation 535 where the failed logical circuit data is rerouted over the logical failover circuit. It will be appreciated that authorization may be obtained if the logical failover circuit is provisioned for a lower quality of service than the failed logical circuit. For example, authorization may be obtained from an ATM circuit customer with a QoS parameter of CBR to reroute logical circuit data to a failover logical circuit with a QoS parameter of VBR real time. It will be appreciated that in some instances, a customer unwilling to accept delay and variable transmission rates for high priority data (such as voice) may not wish data to be rerouted over a lower priority circuit. The logical operations 500 then end.
[0052] It will be appreciated that in an alternative embodiment of the present disclosure, the network management module 176 may be configured to provision an appropriate logical failover in real time upon identifying a failure in a logical circuit. In this embodiment, the network management module 176 , after identifying the QoS parameter for the failed logical circuit, may build a failover circuit with logical connections having the same QoS parameter for rerouting the failed logical circuit data. It should be understood that for portions of the logical failover circuit passing through a data network operated by a different carrier (such as an IEC data network), the rerouting carrier may negotiate a comparable quality of service so that quality may be maintained between a host device and a remote device.
[0053] It will be appreciated that in one embodiment of the present disclosure, the prioritization applied to the rerouting of logical circuit data logical circuit failover procedure may be initiated as a service offering by a Local Exchange Carrier (LEC) or an Inter-Exchange Carrier (IEC) to priority customers for rerouting logical circuit data. If a priority customer is not a subscriber, the service may still be initiated and the priority customer may be billed based on the length of time the prioritized logical failover circuit was in use.
[0054] It will be appreciated that the embodiments of the disclosure described above provide for a method and system for prioritized rerouting of logical circuit data in a data network. When a logical circuit failure is detected, the data in the logical circuit may be rerouted to a logical failover circuit at the same quality of service provisioned for the failed logical circuit. The various embodiments described above are provided by way of illustration only and should not be construed to limit the invention. Those skilled in the art will readily recognize various modifications and changes that may be made to the present invention without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present disclosure, which is set forth in the following claims.
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An example method involves, when a first quality of service parameter for a failed logical circuit is equal to or less than a second quality of service parameter for a logical failover circuit, rerouting data from the failed logical circuit to the logical failover circuit without requiring authorization from a customer to communicate the data at the second quality of service parameter. When the second quality of service parameter for the logical failover circuit is a lower level of quality than the first quality of service parameter for the failed logical circuit: a customer is prompted for an authorization to communicate the data via the logical failover circuit at the second quality of service parameter; when the authorization is received, the data is rerouted from the failed logical circuit to the logical failover circuit; and when the authorization is denied, the data is not rerouted to the logical failover circuit.
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TECHNICAL FIELD
This invention relates to portable machines used for welding or fusing individual thermoplastic sheets and for repairing tears and ruptures in existing thermoplastic membranes. More particularly, it relates to a heating and welding system for such machines wherein a strip of thermoplastic sheeting is used as the material to join overlapping or abutting edges of individual thermoplastic sheets by heat and pressure.
BACKGROUND ART
The construction of large, impermeable, thermoplastic membranes is typically accomplished by transporting rolls of bulk thermoplastic materials to a work site. Individual sheets are unrolled, cut to length, and then positioned on a supporting structure so that the edges of the sheets may be welded or fused together in situ to form a singular unitary membrane. Such membranes are used as roof coverings, lagoon and reservoir liners, and also as large tarpaulins, among others.
The welding or fusing of the thermoplastic sheets, in the field, by means of portable welding machines is conventionally achieved by abutting or overlapping the edges of the individual sheets. Heat is applied to the edges until they have changed from a solid to a tacky viscous fluid state. The heated portions are then compressed together while they are hot so that the sheets, upon cooling, become a single unitary membrane consisting of a multiple of fused sheets.
The welding together of individual sheets in situ is accomplished in the prior art in one of two ways. The first is where the sheets are initially laid out with their edges overlapping. In that case an upper and a lower sheet, referred to as opposing sheets, are separated and a heat source is interposed between them. The heat source heats a bottom portion of the upper sheet along its edge, and a top portion of the lower sheet along its edge. The two heated portions are then compressed together while they are hot to form a welded membrane. For the other way, the individual sheets, referred to as primary sheets, are laid out with either abutting or overlapping edges and the sheets are fused by welding a strip or tape of thermoplastic material along the butt or overlap, forming a seam. In that case, three individual sheets are involved, the two primary sheets and a strip or tape. The strip or tape is fused equally to both primary sheets.
Conventionally, the tape or strip is applied from the top and placed onto the two primary sheets below which are lying on the supporting structure. In that case, the tape or strip is the upper sheet. The heat source is interposed between the tape or strip and the primary sheets below. The bottom of the tape or strip is heated along with the top of the edges of the primary sheets. The strip is the opposing sheet relative to the primary sheets. The weld is completed following the compression of the heated portions into a unitary membrane. In either case, a heat source is interposed between an upper and a lower sheet or sheets and the primary or opposing sheets are heated in preparation for the compression. The upper and lower sheet or sheets are hereinafter referred to as opposing sheets for all cases. In the latter type of cases, tape or strip is hereinafter referred to as strip.
Machines of the referenced type are generally motor driven, self-propelled machines in which a drive motor is connected through a drive train to one or more drive wheels. A heating means, commonly a hot-air blower, and a sheet handling means are provided on the machine for guiding at least one of the opposing sheets through the machine and past the heating means as the machine travels along. The edges of the opposing sheets are heated and then laid or placed together while hot. The laminate of hot sheets then passes through a compression means and out of the machine as the weld is completed automatically.
In conventional portable welding machines, a single heat or temperature source heating means heats the opposing sheets until a fluid or semi-solid state has been achieved to allow for the compression and fusion of the sheets. When using a single heat means which operates at a constant temperature a problem is presented when different thermoplastic sheet materials are to be fused. A similar problem is presented when the same or different thermoplastic sheet materials are to be fused but the sheets are of different thicknesses.
Thermoplastic sheet materials have a range of thermal properties. For example, a typical molding temperature for plasticized vinyl begins at 285° F. and that for polypropylene typically begins at 350° F. It is often desirable to fuse two such different materials, particularly when called upon to repair a tear or rupture in an existing membrane.
The quantity of heat required to fuse thermoplastic materials varies with the thicknesses of the sheets to be fused. It is often desirable to fuse sheets of different thicknesses, particularly when using a strip to fuse two primary sheets. When fusing sheets of different thicknesses, the different thermal requirements of each of the opposing sheets lead to different temperature or heat means differential output requirements for each of opposing sheets. The differential requirements are compounded when the sheets are of both different thermoplastic materials and different thicknesses.
A similar heat differential problem exists when similar or different individual sheets have been exposed to different ambient environments prior to the time when welding begins. This situation typically occurs when the individual sheets, which are to become a roofing membrane, are laid out in the sunlight and reach high temperatures due to natural solar radiation and the welding is started by using a strip of material previously stored in a sheltered location and thus is at ambient air temperatures.
Conventionally, an operator uses a single heat source operating at a single temperature until the opposing sheets are somewhat fluidized. In other words the different thermal requirements of the opposing sheets are generally disregarded in conventional systems. The result of this technique, typically achieved by single temperature hot-wedge or hot-plate machines, is often a faulty weld caused by the over curing or hardening of the sheet with the lower thermal requirements. Since a hardened membrane cracks and fails, this result is undesirable. A similar result is achieved by single heat source hot air machines where the operator either manually distributes the heat between the opposing sheets using intuition, experience, or skill, or applies heat generally as is done with the hot-wedge machines.
The aforementioned temperature and heat differential problems are solved by the present invention. The present invention is limited to electric radiant heat sources in order to overcome other environmental problems typically encountered in the field when using portable hot air machines. The hot air machine, while amendable to a dual heat source welder, is too sensitive to outdoor wind conditions to be a practical solution to the aforementioned problems. The natural wind often blows away the hot air leading to ineffective or spotty heating and welds.
A second problem is presented when the opposing heated sheets are compressed together with conventional portable welding machines. Following the heating of the sheets with a conventional machine, the sheets are fused, by a compression means, into a unitary membrane. The conventional compression means consists of a single roller or wheel and thus the sheets are compressed once and essentially instantaneously as the machine travels on. The region of compression action is in the shape of a line transverse to the major axis of the weld and beneath the roller. That line region then travels along the seam automatically at the linear velocity of the machine.
The conventional compressing technique creates problems. Impurities, particularly bubbles, which are trapped between the sheets prior to the compression, have a tendency to be distributed along the seam or are trapped within the weld without lateral expulsion or dissolution. This creates undesirable welds containing impurities. The problem is compounded when combined with the aforementioned thermal differential requirements. In cases where a bubble is trapped in the weld and the upper opposing sheet has been overheated, the bubble forms a hardened dome, a burned-bubble, which is easily fractured.
There is therefore a need for a portable machine that provides compression of the hot sheets for an extended period of time to decrease the incidence of impurity entrapment in the weld, particularly with respect to bubbles. This problem is solved by the present invention.
BRIEF DISCLOSURE OF INVENTION
In accordance with the above objects for the improvement of thermoplastic sheet weld quality, substantial improvements can be made by providing heating means comprising two independent, proportionally controlled electric radiant heat sources. When embodied within a portable machine and interposed between the opposing sheets, each radiant heat source is dedicated to, directed at, and adjusted for the thermal requirements of one of the opposing sheets. By using different radiant heat source output temperatures to achieve the different melting points of each of the opposing sheets, at essentially the same time, each sheet can be correctly and consistently melted to allow for a complete and uniform fusion along the weld.
The advantages of the present invention result from the elimination of the aforementioned prior art thermal differential requirement problems. Those problems are solved by controlling the temperature and the amount of heat that each opposing sheet is exposed to.
With the present invention, when one of the opposing sheets requires more or less heat than the other, the heat source output dedicated to that sheet is increased or decreased accordingly. As a result, higher quality and more consistent welds are achieved. Reduced installation costs also result because fewer sheets are destructively burned when being welded to different opposing sheets that have higher thermal requirements. Additionally, greater flexibility of use is a result of the invention due to the choice of thermoplastic materials for use in repairing and splicing thermoplastic sheets now available. For example, low melting point strips may be used to repair tears and ruptures in existing high melting point membranes without seeking out the manufacturer of the membrane in order to match the thermal properties of the materials.
Substantial improvements are also made, in accordance with the above objects, by providing compression means which distribute the compressive forces over a plane, rather than in a line, and for a greater duration of time, rather than relatively instantaneously. By providing an endless belt and by providing for an increased time of compression, impurities found in the fluids have time to move laterally and be expelled from the weld or to be dissolved or compressed before the materials cool and return to a relatively solid state. As a result, the incidence of large bubble entrapment is reduced and thus, a higher quality weld is produced.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagrammatic side view showing the structural relationship of the primary components comprising the instant invention to the materials and process affected thereby.
FIG. 2 is a view in side elevation showing the preferred embodiment of FIG. 1.
FIG. 3 is a view in top elevation showing the preferred embodiment of FIG. 1.
FIG. 4 is a view in rear elevation showing the preferred embodiment of FIG. 1 with the direction of travel being away from the viewer.
FIG. 5 is a view in front elevation showing the preferred embodiment of FIG. 1.
FIG. 6 is a view in bottom elevation of the preferred embodiment of FIG. 1.
FIG. 7 is an electrical diagram showing the control means relationships of the primary components comprising the preferred embodiment.
FIG. 8 is a view of the preferred embodiment in use.
In describing the preferred embodiment of the invention, which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION
Referring to FIG. 1, there is shown a diagrammatic side view representing the structural relationships of the primary components comprising this invention. With reference also to FIG. 8, the perspective, the assembly of the membrane is commenced by laying out, in situ, individual thermoplastic sheets 20 on a supporting structure 22, such as a structural roof deck. The layout may be by either abutting or overlapping the edges of the individual sheets since the object is to fuse multiple individual sheets to form a larger unitary membrane 46.
The machine is initially positioned over the edges of two of the individual sheets 20, if they are abutted, or the uppermost edge if the sheets are overlapped. A roll of thermoplastic weld material 24, centered within the machine, is centered over the edges. A strip 28 from the roll 24 is fed through and laterally held in position by a strip guide 26.
The strip 28 is guided past a first electric radiant heat source 30 where the bottom side of the strip 28 is exposed to heat and radiant energy. The strip 28 travels past the heat source 30 at the forward velocity of the machine while tension in the strip 28 causes new unexposed material from the roll 24 to be drawn into position for heating. As the machine moves in a forward direction 12 at a uniform velocity, the strip 28 is heated at a uniform rate. The length of strip 28 that is heated is equal to the distance that the machine travels over any given time span. After the strip 28 is exposed to the first radiant heat source 30, the strip 28 is pulled unguided into contact with the lower opposing sheets 20. A line of contact 34 is made while the strip 28 is still hot.
Simultaneously with the heating of the strip 28, the fixed lower sheets 20 are exposed to a second electric, radiant heat source 32. The lower radiant electric heat source 32 travels above the lower sheets 20 at a uniform velocity equal to the forward velocity of the machine because it is attached to the machine. The length of materials that are heated is always equal to the distance that the machine travels over any given time span.
As the machine moves forward and heats the top of the lower sheets 20, the strip 28 is drawn down upon the lower sheets 20 while all of the sheets 20 and 28 are still hot. They meet at a forward moving line of initial contact 34.
The upper radiant heat source 30 is dedicated to the heating of the bottom of the strip 28. The lower radiant heat source 32 is dedicated to the heating of the tops of lower sheets 20. The outputs of heat sources 30 and 32 are adjusted proportionately by proportionate control means 14 as means to affect the independent dedication. With both radiant heat sources 30 and 32 mounted within a single housing 31, said sources are interposed between the sheets 20 and the strip 28.
A compression belt 36 compresses the sheets together while they are still hot. The belt 36 travels around a pair of rollers 38 and 40 and relative to the initial line of contact 34. The belt 36 rolls over the line of contact 34 and fuses the sheets 20 and 28 together by gravity driven compression. The compression is applied over the length of the belt 36. The welding process is completed as the machine travels over a completion line 44, the end of the welding process. A welded sheet 46, a unitary membrane, is thus produced.
The initial radiant energy output level of each independent heat source 30 or 32 may be established by reference to data, operator experience, or iteration based on observation and testing. For example, by directly observing the heated strip 28 just prior to the initial line of contact 34, or by touching it with a small probe, the operator can decide whether the bottom of the strip 28 is tacky or behaves more like a semisolid than a solid. If it is not tacky or if it behaves like a solid, the output of the upper heat source 30 is increased by proportional control means 14. The process is then repeated for the top of the lower sheets 20 with the lower heat source 32. This initialization process is repeated until an optimum output of each of the heat sources 30 and 32 has been established. An experienced welder may make the aforementioned adjustments by observing and testing the completed weld; if not sheets are burned or hardened and the weld depth is approximately the thickness of the sheets, the outputs are correctly set.
Referring to FIGS. 2 through 6, the preferred embodiment of the portable, thermoplastic sheet, welding machine has a protective housing 10 which contains the electric control and power circuitry and drive motor and drive means connected to drive wheels 13. The electric control means 14 are mounted on a detachable panel 15 on the face of the housing 10 for access. It is inclined for visibility. A hand-held electric remote control means 16 is connected to the panel 15. An enabling power source 18 is interconnected therein.
A roll of thermoplastic strip 24 provides a supply of welding material. The roll 24 spins freely within the housing 10 and is supported on the housing walls by a horizontal shaft 25. The roll 24 is centered relative to the strip guide 26. Hand slots 27 are cut from the housing walls for manually transporting and positioning the machine. A carrying handle is located approximately above the center of gravity of the machine.
An upper, independent, electric radiant heat source 30 is attached within a heater housing 31 in a near vertical orientation. A lower independent radiant heat source 32 is also attached within the housing 31, but in a near horizontal orientation. The heater housing 31 is closed on four sides and open on the bottom and back sides for the application of the heat to the thermoplastic sheets 20 and 28. The bottom opening is dedicated to the lower heat source 32 and the back opening is dedicated to the upper heat source 30. The lower heat source 32 heats the top of the lower sheets 20; the upper heat source 30 heats the bottom of the strip 28. Because both heat sources 32 and 30 are attached within a single heater housing 31, and the heater housing 31 is located for the heating of the opposing faces of the opposing sheets 20 and 28, the heat sources 30 and 32 are interposed between opposing sheets. The heater housing 31 is attached to the housing 10 by hinge means 33. The heater housing 31 contains a roller 48 or a skid on its leading edge to rotate the housing 31 around the hinge means 33 when contour of the underlayment changes. The roller 48 and the hinge means 33 keep the lower heat source 32 a fixed distance from the lower sheets 20 when traversing surfaces with changing contours.
An endless compression belt 36 is contained in a detachable belt housing 37 for access and maintenance. The belt housing 37 is connected to housing 10 by a gimbal means 41 to provide uniform compression across the compression plane. The endless belt 36 rotates around a pair of rollers 38 and 40. The rollers 38 and 40 are free-wheeling and attached to the inside walls of the belt housing 37. A pair of drive wheels 13 are contained in a separate detachable wheel housing. The wheel housing is connected to the housing 10 and contains drive means and means for the rotation of the wheel housing for steering.
Referring particularly to FIG. 8, the preferred embodiment is shown in perspective in operating position. Subsequent to the set-up, the operator stands to the side and steers the machine while the weld is completed automatically. Under fluctuating environmental conditions, the independent radiant heat sources 30 and 32 may be further adjusted by control means 14 according to the aforementioned procedures. Remote control means 16 are used to steer the machine and to control its forward speed.
Referring to FIG. 7 and FIG. 3, the aforementioned electric control means 14 are more particularly described as follows. An enabling power source 18 is connected thereto. A master switch 58 enables the circuitry. A drive motor speed controller means 52 controls the forward speed of the machine. Right and left tracking is controlled by controller means 50. The total heat output of both radiant heat sources is controlled at controller means 54 and that energy is divided between the two sources proportionally by proportional control means 56, in whatever proportion is required as determined by the differential heat requirements of the opposing sheets. Controller means 54 is, in one embodiment, a conventional triac power control circuit which controls the power by controlling the duty cycle or the conduction angle. Proportion control 56 is, in one embodiment, two such conventional power control circuits having inversely proportional duty cycles or conduction angles. Other conventional circuits which are obvious to those of ordinary skill in the electronic and electrical control arts are also contemplated by the invention.
While certain embodiments of the present invention have been disclosed in detail, it is to be understood that various modifications may be adopted without departing from the spirit of the invention or scope of the following claims.
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This invention relates to portable machines for welding together individual thermoplastic sheets in situ. The machine heats different and opposing thermoplastic sheets using independently controlled electric, radiant heat sources and then compresses the sheets beneath an endless compression belt to complete the weld thus forming a unitary membrane.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application claims one or more inventions which were disclosed in Provisional Application No. 61/413,083, filed Nov. 12, 2010, entitled “METHOD AND APPARATUS FOR RAPID PREPARATION OF MULTIPLE SPECIMENS FOR TRANSMISSION ELECTRON MICROSCOPY”. The benefit under 35 USC §119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is in the technical field of methods of sample preparation and manipulation for preparing a specimen for transmission electron microscopy (TEM) examination. More particularly, the present invention is in the technical field of sample preparation and manipulation by methods of in-situ lift-out techniques.
[0004] 2. Description of Related Art
[0005] The standard in-situ lift-out method involves moving a micromanipulator probe to a sample membrane that was previously milled from a wafer by use of a focused ion beam/scanning electron microscope (FIB/SEM) or similar machine. This leaves the sample membrane approximately 1-2 microns thick with varying length and height (typically 5-15 micron length and 5-15 micron height). The micromanipulator probe is then welded to the sample membrane by ion beam assisted metal deposition. When the weld is secured, the sample membrane is then cut from the wafer by a focused ion beam (FIB) and extracted from the wafer.
[0006] The probe then moves the sample to a transmission electron microscope (TEM) grid where it is welded to the TEM grid by ion beam assisted metal deposition. When the sample membrane is secured to the TEM grid, the probe is cut from the sample by FIB. The sample membrane is then milled again by FIB until it is thin enough for use in a TEM, typically between 50-200 nanometers thick. The entire method is done within the FIB/SEM machine chamber while it is activated and under vacuum.
[0007] The current method of in-situ lift-out has a low productivity, as the number of samples that are produced is relatively low in comparison to the total amount of time and effort that is used for this purpose. Features that shorten the time of preparing a sample and/or increase user productivity are highly desirable in this field.
[0008] The current method also has problems in metal deposition steps where excess material may sputter on, and contaminate unintended objects.
SUMMARY OF THE INVENTION
[0009] The present invention provides a method and apparatus for in-situ lift-out rapid preparation of samples for electron microscopy. The invention uses adhesives and/or spring-loaded locking-clips in order to place multiple sample membranes on a single support grid and eliminates the use of standard FIB-assisted metal deposition as a bonding scheme. Therefore, the invention circumvents the problem of sputtering from metal deposition steps and also increases overall productivity by allowing for multiple samples to be produced without opening the FIB/SEM vacuum chamber.
BRIEF DESCRIPTION OF THE DRAWING
[0010] FIG. 1 is a flowchart demonstrating the method.
[0011] FIG. 2 is a perspective view of a lift-out system.
[0012] FIG. 3 is a perspective view of the continuation of a lift-out system from FIG. 2 .
[0013] FIG. 4 is a perspective view of the continuation of a lift-out system from FIG. 3 .
[0014] FIG. 5-A is a perspective view of an alternate embodiment of a lift-out system.
[0015] FIG. 5-B is a perspective view of an alternate embodiment of a lift-out device.
[0016] FIG. 5-C is a side view of an alternate embodiment of a lift-out device of FIG. 5-B .
[0017] FIG. 6 is a wide perspective view of a continuation of a lift-out system from FIG. 4 .
[0018] FIG. 7 is a close up perspective view of FIG. 6 and continuation of a lift-out system from FIG. 6 .
[0019] FIG. 8 is a close up perspective view of FIG. 6 and continuation of a lift-out system from FIG. 7 .
[0020] FIG. 9-A is a wide perspective view of a repetition of a lift-out system.
[0021] FIG. 9-B is a wide perspective view of an alternate embodiment of FIG. 9-A .
[0022] FIG. 9-C is a wide perspective view of an alternate embodiment of FIG. 9-A .
[0023] FIG. 10-A is a wide perspective view of an alternate embodiment of FIG. 9-A .
[0024] FIG. 10-B is a close up cross sectional view of FIG. 10-A .
DETAILED DESCRIPTION OF THE INVENTION
The Method
[0025] Referring now to FIG. 1 , there is shown a flowchart 100 of the method. The method is comprised of the following steps shown in the flowchart
101 : Place wafer, microprobe assemblies and TEM support grid into FIB/SEM chamber—Set up all the necessary parts in order to do an in-situ lift-out according to the method shown in the flowchart 100 . A wafer, microprobe assemblies, and TEM support grids are loaded into a FIB/SEM chamber, which is then activated, placing all its contents under vacuum. 102 : Place microprobe assembly in micro gripping and manipulation device—a micro gripping and manipulation device reaches and grasps a micromanipulator probe, which has an adhesive or a spring loaded locking clip at the end of it. 103 : Ion mill sample membrane from wafer—the FIB/SEM is used to create a sample membrane by etching out portions of the wafer using an ion beam. The sample membrane will be approximately 5-15 microns long, 5-15 microns deep, and less than 200 nanometers thick when the step is completed. The sample membrane will also be partially cut away from the wafer. 104 : Attach microprobe assembly to sample membrane—the micro gripping and manipulation device moves the micromanipulator probe so that the adhesive or spring loaded locking clip will touch and attach to the sample membrane. The sample membrane is attached to both the wafer and the microprobe assembly. 105 : Detach sample membrane from wafer—the sample membrane is completely severed from the wafer by the FIB/SEM ion beam. The sample membrane is now only attached to the microprobe assembly. 106 : Move microprobe assembly with attached sample membrane to a TEM support grid—the microprobe assembly is moved from the wafer to the TEM support grid so that the sample membrane is over a hollow viewing window. 107 : Secure microprobe assembly with attached sample membrane to a TEM support grid—the microprobe assembly is attached to the TEM support grid using an adhesive or a spring loaded locking clip so that it is secured to the TEM support grid. 108 : Release microprobe assembly from micro gripping and manipulation device—the micro gripping and manipulation device releases the microprobe assembly with sample membrane only attached to the TEM support grid. 109 : Repeat Process?—the process may be repeated to create and attach more sample membranes to the TEM support grid.
[0035] If yes, return to step 102 and repeat the method;
[0036] If no, go on to the last step.
110 : Remove TEM support grid from FIB/SEM for examination—the TEM support grid has as many sample membranes attached to it as required by the user and the FIB/SEM is deactivated, releasing the vacuum chamber. The TEM support grid is removed so that it can by viewed by a TEM.
The Apparatus
[0038] Referring now to FIG. 2 to FIG. 4 , there is shown a microprobe assembly 1 held by a micro gripping and manipulation device 2 , which is next to a wafer 6 . The microprobe assembly 1 consists of a micromanipulator probe 3 with a sample attachment element—in this embodiment shown as an adhesive 4 —at the end opposite the end held by device 2 . A sample membrane 5 is part of the wafer 6 .
[0039] In more detail, still referring to FIG. 2 to FIG. 4 , the microprobe assembly 1 is moved by the micro gripping and manipulation device 2 to the sample membrane 5 . The sample membrane 5 was previously ion milled by FIB from the wafer 6 . The micromanipulator probe 3 is attached to the sample membrane 5 by the adhesive 4 . After the adhesive 4 bonds the sample membrane 5 to the micromanipulator probe 3 , the sample membrane 5 is detached from the wafer 6 and moved by the micro gripping and manipulation device 2 holding the microprobe assembly 1 with respect to the wafer 6 .
[0040] In reference to the flowchart 100 shown in FIG. 1 , FIG. 2 is shown after the following steps were previously completed; “Place wafer, microprobe assemblies and TEM support grid into FIB/SEM chamber” 101 ; “Place microprobe assembly in micro gripping and manipulation device” 102 ; “Ion mill sample membrane from wafer” 103 . FIG. 3 is shown after the step, “Attach microprobe assembly to sample membrane” 104 . FIG. 4 is shown after the step, “Detach the sample membrane from wafer” 105 .
[0041] In further detail, still referring to FIG. 2 to FIG. 4 , the wafer 6 is loaded into a Focused Ion Beam/Scanning Electron Microscope (FIB/SEM) machine chamber along with the micromanipulator probe 3 and adhesive 4 before beginning the process. The micro gripping and manipulation device 2 is attached to the FIB/SEM machine so that it may manipulate the micromanipulator probe 3 . The microprobe assembly 2 must be sufficiently small to capture the sample membrane 5 typically in sizes of five to fifteen microns long, five to fifteen microns deep and approximately 200 nanometers thick or less, but not subject to these limits. The micromanipulator probe 3 may vary in size, length, or geometry, but must be usable with typical manipulating devices that are compatible with FIB/SEM machines. The adhesive 4 may either be preloaded on the micromanipulator probe 3 prior to insertion into a FIB/SEM machine or a small amount of the adhesive may be placed in the FIB/SEM machine where it is accessible to the micromanipulator probe 3 .
[0042] The construction details of the invention as shown in FIG. 2 to FIG. 4 are that the micromanipulator probe 3 be made of a metal typically used in the art, such as tungsten, molybdenum, or others. The micromanipulator probe 3 is cylindrical and tapers to a point where the adhesive 4 is placed. The adhesive 4 , in its preferred embodiment would be usable in vacuum chamber environments of a FIB/SEM machine and would also be curable by exposing it to charged electron particles such as particles exerted from a FIB/SEM machine.
[0043] Referring now to FIG. 5-A to FIG. 5-C , there is shown a sample wafer 24 attached to a microprobe assembly 20 , which is held by a micro gripping and manipulation device 21 , which is near a wafer 25 . The microprobe assembly 20 consists of a micromanipulator probe 22 attached to a spring-loaded locking clip 23 at its end.
[0044] In more detail, still referring to FIG. 5-A to FIG. 5-C , the microprobe assembly 20 attaches the sample membrane 24 to the micromanipulator probe 22 using the spring loaded locking clip 23 . The sample membrane 24 is held in place by the force applied from the spring loaded locking clip 23 . The sample membrane 24 was previously ion milled by FIB from the wafer 25 . This is an alternate embodiment of the invention.
[0045] In further detail, still referring to FIG. 5-A to FIG. 5-C , the wafer 25 is loaded into a Focused Ion Beam/Scanning Electron Microscope (FIB/SEM) machine chamber along with a micromanipulator probe 22 and spring loaded locking clip 23 before beginning the process. The micro gripping and manipulation device 21 is attached to the FIB/SEM machine so that it may manipulate the micromanipulator probe 22 . The microprobe assembly 20 must be sufficiently small to capture the sample membrane 24 typically in sizes of five to fifteen microns long, five to fifteen microns deep, and approximately 200 nanometers thick or less, but not subject to these limits.
[0046] The micromanipulator probe 22 may vary in size, length, or geometry, but must be usable with typical manipulating devices that are compatible with FIB/SEM machines. The spring loaded locking clip 23 is securely attached to the micromanipulator probe 22 and must apply sufficient force in order to latch and hold onto the sample membrane 24 .
[0047] The construction details of the invention as shown in FIG. 5-A to FIG. 5-C are that the micromanipulator probe 22 be made of a metal typically used in the art, such as tungsten, molybdenum, or others. The spring loaded locking clip 23 is made of a metal typically used in the art, such that the metal is pliable as to exert a force suitable to hold the sample membrane 24 without inflicting damage to the sample membrane 24 . The spring loaded locking clip 23 may vary in shape, size, and geometry as long as it can deliver the same function.
[0048] Referring now to FIG. 6 to FIG. 8 , there is shown a sample membrane 5 attached to a microprobe assembly 1 held by a micro gripping and manipulation device 2 and attached to a grid adhesive 7 which is attached to a modified TEM mesh support grid 8 . The microprobe assembly 1 consists of a micromanipulator probe 3 and an adhesive 4 at the end.
[0049] In more detail, still referring to FIG. 6 to FIG. 8 , the microprobe assembly 1 with the sample membrane 5 attached by the adhesive 4 is moved by the micro gripping and manipulation device 2 to the modified TEM mesh support grid 8 . The microprobe assembly 1 is then bonded by the grid adhesive 7 to the TEM mesh support grid 8 in such a way that the attached sample membrane 5 will be in a hollow viewing window of the modified TEM mesh support grid 8 . When the grid adhesive 7 is sufficiently cured so that the microprobe assembly 1 is bonded to the modified TEM mesh support grid 8 , the micro gripping and manipulation device 2 releases the microprobe assembly 1 . In reference to the flowchart 100 shown in FIG. 1 , FIG. 6 and FIG. 7 is shown after the following steps; “Move microprobe assembly with attached sample membrane to a TEM support grid” 106 ; “Secure microprobe assembly with attached sample membrane to a TEM support grid” 107 . FIG. 8 is shown after the step, “Release microprobe assembly from micro gripping and manipulation device” 108 .
[0050] In further detail, still referring to FIG. 6 to FIG. 8 , the modified TEM mesh support grid is placed in a FIB/SEM chamber before beginning the process as shown in the flowchart of FIG. 1 . The grid adhesive 7 would be preloaded onto the modified TEM mesh grid 8 or a small amount of the grid adhesive 7 may be placed in the FIB/SEM machine where it is accessible to the microprobe assembly 1 . The modified TEM mesh support grid 8 is built with hollow viewing windows where the sample membrane 5 may be viewed later by a TEM or similar machine.
[0051] The construction details of the invention as shown in FIG. 6 to FIG. 8 are that the grid adhesive 7 would be curable either inside or outside the vacuum chamber of a FIB/SEM machine. The grid adhesive 7 must also be able to sufficiently secure the microprobe assembly 1 to the modified TEM mesh support grid 8 . A modified TEM mesh support grid 8 is a standard 3 millimeter mesh support grid, typically made of metals used in the art, such as copper, molybdenum or others with mesh of viewing windows incorporated into its structure. It would typically be approximately 20-50 microns thick and circular or semicircular with a typical diameter of 3 millimeters. It has been modified by cutting a portion of the mesh support grid off to expose the viewing windows at the edge of the cut.
[0052] Referring now to FIG. 9-A , there is shown a modified TEM mesh support grid 32 attached to a group of microprobe assemblies 30 which are each individually attached to a sample membrane 31 .
[0053] In more detail, still referring to FIG. 9-A , the modified TEM mesh support grid 32 has been processed with multiple sample membranes 31 from their attached microprobes assemblies 30 . The method in the flowchart shown in FIG. 1 is repeated until the desired number of sample membranes 31 are placed onto the modified TEM mesh support grid 32 . In reference to the flowchart 100 shown in FIG. 1 , FIG. 9-A is shown after the following step, “Repeat Process?” 109 , has occurred multiple times. The step “Repeat Process?” 109 , repeats the method starting at the step, “Place microprobe assembly in micro gripping and manipulation device” 102 . When the process no longer needs to be repeated, then the last step, “Remove TEM support grid from FIB/SEM for examination” 110 , would follow.
[0054] Referring now to the invention shown in FIG. 9-B , there is shown a micro gripping and manipulation device 40 near a group of micromanipulator probes 41 that are attached to a temporary bonding agent 42 , which is attached to a modified TEM slotted support grid 43 .
[0055] In more detail, still referring to FIG. 9-B , the micro gripping and manipulation device 40 may detach the micromanipulator probe 41 and use the previously described method as shown in the flowchart in FIG. 1 . After the method described is completed, the micromanipulator probe 41 may be returned to the modified TEM slotted support grid 43 . The temporary bonding agent 42 may allow for the micromanipulator probe 41 to detach and reattach to the modified TEM slotted grid 43 . This is an alternate embodiment of the invention.
[0056] In further detail, still referring to FIG. 9-B , the modified TEM slotted support grid 43 with the temporary bonding agent 42 is placed in a FIB/SEM machine chamber before beginning the process as shown in the flowchart of FIG. 1 . The temporary bonding agent 42 allows the micromanipulator probe 41 to bond to the modified TEM slotted grid 43 . The micro gripping and manipulation device 40 may grab the micromanipulator probe 41 and pull it from the modified TEM slotted grid 43 . The micro gripping and manipulation device 40 may also move a micromanipulator probe 41 to the modified TEM slotted grid 43 where contact with the temporary bonding agent 42 will allow the pieces to bond.
[0057] The construction details of the invention as shown in FIG. 9-B are that the temporary bonding agent 42 to be strong enough to securely hold a micromanipulator probe 41 but weak enough to detach the micromanipulator probe 41 from it without damage to the micromanipulator probe 41 when force is applied by the micro gripping and manipulation device 40 . The temporary bonding agent 42 may also be able to reattach a micromanipulator probe 41 to the modified TEM slotted support grid 43 by contact and force applied without damage to the micromanipulator probe 41 .
[0058] The modified TEM slotted support grid 43 is a typical TEM slotted support grid used in the art. It is approximately 3 millimeters in diameter with a slotted hole in the middle. It is made of typical metals used in the art, such as copper, molybdenum or others. The TEM slotted support grid is modified by cutting a portion away from the grid so that the cut is roughly parallel with the long axis of the hollow slot. The extent of cut is variable, but leaves the hollow slot of the slotted TEM grid intact.
[0059] Referring now to 9 -C, there is shown a micro gripping and manipulation device 50 near a micromanipulator probe 51 which is attached to a temporary bonding agent 52 , which is attached to a modified TEM slotted support grid 53 .
[0060] In more detail, still referring to FIG. 9-C , the micro gripping and manipulation device 50 may manipulate the micromanipulator probe 51 and use the previously described method shown in the flowchart of FIG. 1 . After the method described is completed, the micromanipulator probe may be returned to the modified TEM slotted support grid 53 . The temporary bonding agent 52 may allow for the micromanipulator probe 51 to detach and reattach to the modified TEM slotted support grid 53 . This is an alternate embodiment of the invention.
[0061] In further detail, still referring to FIG. 9-C , the modified TEM slotted support grid 53 with the temporary bonding agent 52 is placed in a FIB/SEM machine chamber before beginning the process as shown in the flowchart of FIG. 1 . The temporary bonding agent 52 allows a micromanipulator probe 51 to bond to the modified TEM slotted support grid 53 . The micro gripping and manipulation device 50 may grab the micromanipulator probe 51 and pull it from the modified TEM slotted support grid 53 . The micro gripping and manipulation device 50 may also move a micromanipulator probe 51 to the modified TEM slotted support grid 53 where contact with the temporary bonding agent 52 will allow the pieces to bond.
[0062] The construction details of the invention as shown in FIG. 9-C are that the temporary bonding agent 52 be strong enough to securely attach a micromanipulator probe 51 but weak enough to be able to detach the micromanipulator probe 51 from it without damage to micromanipulator probe 51 when force is applied by the micro gripping and manipulation device 50 . The temporary bonding agent 52 will also be used to reattach the micromanipulator probe 51 to the modified TEM slotted support grid 53 by contact and force applied without damage to the micromanipulator probe 51 . The modified TEM slotted support grid 53 is based on a typical TEM slotted support grid used in the art or a close variation of it. It is approximately 3 millimeters in diameter with a slotted hole in the middle. It is made of typical metals used in the art, such as copper, molybdenum or others. A TEM slotted support grid is modified by cutting a portion away from the grid so that it is roughly parallel with the long axis of the slot. The extent of the cut is variable, but leaves the slotted portion of the grid intact. The micromanipulator probe 51 is flat and made of a metal typically used in the art, such as copper, molybdenum or others.
[0063] Referring now to FIGS. 10-A and 10 -B, there is shown a micro gripping and manipulation device 63 near a micromanipulator probe 60 which is attached to a spring loaded locking clip 61 , which is attached to a modified TEM slotted support grid 62 .
[0064] In more detail, still referring to FIG. 10-A and FIG. 10-B , the micro gripping and manipulation device 63 may manipulate the micromanipulator probe 60 and use the previously described method shown in the flowchart of FIG. 1 . After the method described is completed, the micromanipulator probe 60 may be returned to the modified TEM slotted support grid 62 . The spring loaded locking clip 61 may allow for the micromanipulator probe 60 to detach and reattach to the modified TEM slotted support grid 62 . This is an alternate embodiment of the invention.
[0065] In further detail, still referring to FIG. 10-A and FIG. 10-B , the modified TEM slotted support grid 62 with the spring loaded locking clip 61 is placed in a FIB/SEM machine chamber before the process begins as described in the flowchart of FIG. 1 . The spring loaded locking clip 61 allows a micromanipulator probe 60 to attach to the modified TEM slotted support grid 62 . The micro gripping and manipulation device 63 may grab the micromanipulator probe 60 and pull it from the modified TEM slotted support grid 62 . The micro gripping and manipulation device 63 may also move a micromanipulator probe 60 to the modified TEM slotted support grid 62 where contact and applied force with the spring loaded locking clip 61 will allow the micromanipulator probe 60 to attach to the modified TEM slotted support grid 62 .
[0066] The construction details of the invention as shown in FIG. 10-A and FIG. 10-B are that the spring loaded locking clip 61 is strong enough to hold a micromanipulator probe 60 but weak enough to be able to detach the micromanipulator probe 60 from it without damage to the micromanipulator probe 60 when force is applied by the micro gripping and manipulation device 63 . The spring loaded locking clip 61 must also be able to reattach a micromanipulator probe 60 to a modified TEM slotted support grid 62 by contact and force applied without damage to the micromanipulator probe 60 . The spring loaded locking clip 6 may vary in shape, size, and geometry as long as it can deliver the same function.
[0067] The modified TEM slotted support grid 62 is a typical TEM support slotted grid used in the art or a close variation of it. It is typically approximately 3 millimeters in diameter with a slotted hole in the middle. It is made of typical metals used in the art, such as copper, molybdenum or others. The modified TEM slotted support grid 62 is modified by cutting a portion away from the grid so that it is roughly parallel with the long axis of the slot. The extent of cut is variable, but leaves the slotted portion of the support grid intact.
[0068] The advantages include, without limitation, that it allows for multiple sample membranes to be placed on a single TEM support grid for viewing by a TEM or similar machine. The method further avoids the need for assisted metal weld deposition and its inherent metal sputtering on and around the area of interest for microscopy. The method further allows for SEM only type of machines to continue the lift-out process, thereby freeing the more expensive FIB/SEM machine from the downtime of the in-situ lift-out attachment process.
[0069] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.
[0070] Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
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A method and apparatus for in-situ lift-out rapid preparation of TEM samples. The invention uses adhesives and/or spring-loaded locking-clips in order to place multiple TEM-ready sample membranes on a single TEM support grid and eliminates the use of standard FIB-assisted metal deposition as a bonding scheme. Therefore, the invention circumvents the problem of sputtering from metal deposition steps and also increases overall productivity by allowing for multiple samples to be produced without opening the FIB/SEM vacuum chamber.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation-In-Part of copending application Ser. No. 12/164,515 filed Jun. 30, 2008, the contents of which are hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The field of this invention generally relates to a process and composition for removing a scale deposit.
DESCRIPTION OF THE RELATED ART
[0003] During processes, e.g., chemical and petrochemical processes, various fluids can be directly or indirectly associated for transferring energy or mass. As an example, often fluids are associated for heat transfer operations in equipment, such as heat exchangers.
[0004] During such operations, the heat exchanger can become fouled with scale deposits on the various surfaces, including internal components. The scale deposits can contain a variety of components, such as coke and metal sulfides. In some instances, the scale deposits can become quite thick.
[0005] As a result, scale deposits can reduce the heat transfer of the equipment and often can impact performance. In severe cases, the equipment may require replacement. In addition, the scale deposit may become friable, loosen, and foul the internals of downstream equipment.
[0006] As a consequence, it would be desirable to clean such equipment of scale deposit during, e.g., a maintenance shutdown. Unfortunately, cleaning solutions can either be of insufficient strength to remove the scale deposits, or too aggressive and damage the equipment. Consequently, there is a desire to identify a cleaning composition with sufficient strength to remove scale deposits but not damage the equipment.
SUMMARY OF THE INVENTION
[0007] One exemplary embodiment can be a process for removing one or more scale deposits formed on a surface. The process can include contacting the surface with a composition for a period of time sufficient to remove the one or more scale deposits. Generally, the composition includes an effective amount of an organic acid and/or a salt thereof, and an effective amount of an oxidizing agent.
[0008] Another exemplary embodiment may be a process for making a scale removal composition. The process may include combining effective amounts of an organic acid and/or a salt thereof and an oxidizing agent with water forming a composition for removing a scale deposit comprising sulfur.
[0009] A further exemplary embodiment may be a scale removal composition. The scale removal composition can be made by comprising an effective amount of citric acid and/or a salt thereof, an effective amount of hydrogen peroxide, and water.
[0010] The exemplary process and composition disclosed herein is effective for removing scale deposits without aggressively impacting the surface of the apparatus. Thus, the embodiments herein can permit the cleaning of equipment rather than replacing, and allow improving, e.g., the heat transfer efficiency, after cleaning of the equipment. The scale deposits that are being removed are primarily metal sulfides such as iron sulfide, nickel sulfide, iron-nickel sulfide, chromium sulfide, iron-chromium sulfide and mixtures thereof. The scale deposits may also include carbon, most often in the form of coke.
DEFINITIONS
[0011] As used herein, hydrocarbon molecules may be abbreviated C1, C2, C3 . . . Cn where “n” represents the number of carbon atoms in the hydrocarbon molecule.
[0012] As used herein, the term “scale deposit” generally means any accumulation of a material on a surface. The accumulation can be a precipitate or a crystal of one or more of coke or sulfides of iron, nickel or chromium or mixtures thereof.
[0013] As used herein, the term “surface” generally means one or more interior and/or exterior portions of an apparatus, a vessel, or other processing equipment, such as piping; and may have any shape, such as curved, circular, angular, tubular, or flat.
BRIEF DESCRIPTION OF THE DRAWING
[0014] FIG. 1 is a cross-sectional, elevational view of an exemplary heat exchanger.
[0015] FIG. 2 is a cross-sectional, elevational view along line 2 - 2 of FIG. 1 of the exemplary heat exchanger.
DETAILED DESCRIPTION
[0016] Referring to FIGS. 1 and 2 , an exemplary apparatus 100 is depicted, which in this desired embodiment is a shell-and-tube heat exchanger 110 . However, it should be understood that other apparatuses, such as furnaces, reboilers, reactors, or other heat exchangers, may also be suited for application of the embodiments disclosed herein. Particularly, equipment with tubular structures may be particularly suited for application. Equipment, apparatuses, and/or vessels can be fabricated from any suitable material, such as carbon steel, stainless steel and/or titanium. The exchanger 110 can include a shell inlet 112 and a shell outlet 114 for a first fluid and a tube inlet 116 and a tube outlet 118 for a second fluid. The exchanger 110 can further include a shell 120 and one or more tubes 130 , typically in the form of a bundle.
[0017] Such an exchanger 110 can be used in many hydrocarbon processes, such as reforming, aromatic complexing, cracking, alkylating, polymerizing, hydrotreating, dehydrogenating, and isomerizing. Exemplary processes can include dehydrogenation of C3 to C5 paraffins to their corresponding olefins, and the conversion of C3 to C5 hydrocarbons to aromatics. In such processes, often dimethyl disulfide and/or hydrogen sulfide is injected to minimize coke formation in a reactor.
[0018] Unfortunately, the hydrogen sulfide can facilitate the formation of scale deposits 200 on one or more tubes 130 in the exchanger 110 that can reduce heat transfer and foul downstream equipment. Typically, a scale deposit 200 can include any material. Often, the material can include iron and sulfur, but may include other materials such as chromium, carbon, nitrogen, and/or aluminum.
[0019] A scale removal composition can be utilized for removing the scale deposit 200 . The composition can include an effective amount of an organic acid and/or a salt thereof, and an effective amount of an oxidizing agent. The organic acid and/or a salt thereof and the oxidizing agent can be provided in a medium, such as a solvent. An exemplary medium is water, which may include other impurities, such as less than about 500 mg per liter of dissolved solids.
[0020] The organic acid can be citric acid, oxalic acid, nitrilotriacetic acid, and polyacetic acid, with citric acid being preferred. Specific salts of the organic acid can include ammonium citrate, sodium citrate, and potassium citrate, with ammonium citrate being preferred.
[0021] The oxidizing agent can be a compound that evolves oxygen, such as a peroxide, a chlorate, a perchlorate, a nitrate, or a permanganate. Exemplary oxidizing agents are hydrogen peroxide, sodium peroxide, and potassium peroxide, with hydrogen peroxide being preferred.
[0022] The organic acid and/or the salt thereof, and the oxidizing agent in the composition may be in any suitable proportion. Preferably, the organic acid and/or the salt thereof, and the oxidizing agent are in a weight ratio of about 10:1 to about 1:10, about 5:1 to about 1:5, or about 2.5:1 to about 1:2.5. In one preferred composition, the organic acid or salt thereof can be citric acid or ammonium citrate, and the oxidizing agent can be hydrogen peroxide. The weight ratio of the citric acid or ammonium citrate to the hydrogen peroxide can be about 10:1 to about 1:10, about 5:1 to about 1:5, or about 2.5:1 to about 1:2.5.
[0023] The proportions of organic acid and/or the salt thereof, and the oxidizing agent are maintained so that the pH of the composition is neutral, i.e. less than about 7.5 or below and preferred between 5 and 6. The conditions must be maintained to avoid polythionic acid stress corrosion cracking until the scale has been fully removed. It is known that the combination of water and oxygen with the sulfide scale can produce polythionic acid. Once polythionic acid forms during a shutdown, it can cause cracking of sensitized stainless steel. Accordingly, the present invention does not require the normal preventive neutralization practice. Therefore, a basic pH is not needed to prevent the formation of polythionic acid as required by the National Association for Corrosion Engineers recommended practice for preventing polythionic acid stress corrosion cracking, the industry standard. NACE method RP0170 for Protection of Austenitic Stainless Steel and other Austenitic Alloys from Polythionic Acid Stress Corrosion Cracking during Shutdown of Refinery Equipment states that a neutralization solution to prevent polythionic acid stress corrosion cracking must have a pH greater than 9. Maintaining the active oxidizer prevents polythionic acid stress corrosion cracking until the scale has been fully removed. Once the scale has been removed, polythionic acid stress corrosion cracking is no longer an issue.
[0024] The composition can include any suitable amount of the medium in combination with the organic acid or salt thereof. Generally, the composition includes at least about 50%, preferably at least about 80%, and optimally at least about 90%, by weight of the medium. In some preferred embodiments, the medium can include water and the composition may include at least about 50%, preferably at least about 80%, and optimally at least about 90%, by weight of water.
[0025] The composition can be made by combining the organic acid and/or salt, the oxidizing agent, and the medium in any order at ambient conditions, i.e., a temperature of about 20° C. and a pressure of about 100 kPa, in any suitable container. Afterwards, the combination can be stirred until the components are sufficiently mixed.
[0026] The composition can be applied to scale deposits for any suitable time, such as at least about 30, at least about 60, or even at least about 120 minutes at a temperature of about 30° to about 80° C., preferably about 60° C., at a pressure of about 100 to about 10,000 kPa, preferably about 100 to about 1,000 kPa. Desirably, a plurality of applications or leaches are made, such as one, two, three, or even four with each stage of application being, independently, at least about 30, at least about 60, or even at least about 120 minutes. In some preferred embodiments, the applications or leaches can even be longer, such as at least about 1—at least about 3 days for each leach. The time, temperature, pressure, and number of stages can vary depending on the type and amount of scale deposit, and the dimension and location of the surface within the apparatus or vessel. The composition can be applied in a batch or continuous process. As much as about 50%, even at least about 70%, by weight, of the scale can be removed by the embodiments herein.
Illustrative Embodiments
[0027] The following examples are intended to further illustrate the subject matter disclosed herein. These illustrations of embodiments of the invention are not meant to limit the claims of this invention to the particular details of these examples. These examples are based on engineering calculations and actual operating experience with similar processes.
EXAMPLE 1
[0028] Various chemicals are applied to a scale deposit that includes in percent, by weight: 37.5 Fe, 8.6 Cr, 4.3 Ni, 1.0 Al, 32.6 S, and 12.5 C, with a remainder of 3.5% of other components. Several solutions are made at room temperature and atmospheric pressure. Solution A is made by adding 0.15 gram citric acid and 0.2 ml of peroxide to 4 ml of water to yield a solution of about 4%, by weight, of citric acid in water. Solution B is a 5%, by volume, of hydrochloric acid in water. Solution C is obtained by adding 0.15 ml of 30%, by weight, hydrogen peroxide to 2 ml of water to yield a solution of about 8%, by weight, hydrogen peroxide. Solution D is obtained by adding nitric acid to Solution C to obtain 11%, by weight, of nitric acid and hydrogen peroxide. Solution E is obtained by adding 0.15 gram ammonium citrate and 0.2 ml of peroxide to 4 ml of water to yield a solution of about 4%, by weight, of ammonium citrate in water. The results are depicted in the table below.
[0000]
TABLE 1
Total Dissolved Iron
Percent,
Solutions
Chemicals
By Weight
A
Citric Acid and Hydrogen Peroxide
~6-10
B
Hydrochloric Acid
~25
C
Hydrogen Peroxide
~3
D
Nitric Acid and Hydrogen Peroxide
~70
E
Ammonium Citrate and Hydrogen Peroxide
~15
[0029] The amount of iron removed from a scale deposit is depicted above in Table 1. A mineral acid such as HCl and HNO 3 is too aggressive toward the metallurgy of the underlying surface. As depicted above, citric acid or ammonium citrate with hydrogen peroxide is effective, with ammonium citrate and hydrogen peroxide being more effective.
EXAMPLE 2
[0030] A first composition is made by combining 4 ml of H 2 O with 2 ml of H 2 O 2 and 0.15 gram ammonium citrate in a first open beaker, and a second composition is made by combining 4 ml of H 2 O with 2 ml of H 2 O 2 and 0.15 gram citric acid in a second open beaker. Respective quantities of 0.2 gram of the scale deposit of Example 1 are placed into each beaker. The solution is heated to 60° C. for 30 minutes. The scale deposit and solution is centrifuged, and the supernatant is removed and replaced with a fresh solution. The supernatant wash solutions are analyzed by Inductively Coupled Plasma Emission Spectroscopy (ICP) for metals. After four leaches of 30 minutes almost three-fourths of the iron may be dissolved using the ammonium citrate, while only about one-fourth of the iron may be dissolved using citric acid. Results are depicted below.
[0000]
TABLE 2
Percent, By Weight, of Selected Dissolved Metals
Ammonium Citrate
Citric Acid
Leach
Fe
Ni
Cr
Fe
Ni
Cr
#1
18.1
28
1.2
7.2
2.3
1.1
#2
25.3
~100
1.2
5.6
4.6
2.2
#3
18.1
98
1.2
4.8
0
0
#4
13.3
0
0
5.6
0
0
Total
74.8
~100
3.6
23.2
6.9
3.3
EXAMPLE 3
[0031] A composition or solution (Solution F) is made by combining 50 ml of H 2 O, 1.85 gram of ammonium citrate, and 5 ml of H 2 O 2 at 60° C. and is agitated at a rate of 100 agitations per minute. Next, 2.5 gram of the scale deposit of Example 1 is placed into the solution. The initial pH is 5.2 and increases to a pH of 7.2 after 21 hours, and the solution can generate pressure as oxygen evolves. At specified intervals of 21 hours and 45 hours, a sample aliquot is removed and analyzed for iron by ICP and sulfate by ion chromatography (IC) by ASTM D 4327-03 method. After 45 hours, a fresh portion of Solution F is applied to the scale deposit, and a sample of aliquot is removed and analyzed after 24 more hours using the same testing procedures for the samples withdrawn at 21 and 45 hours above. The results are depicted below.
[0000]
TABLE 3
Percent, By Weight, of Dissolved Scale Deposit Components
Time
Fe
Ni
Cr
S
1. After 21 hours
36.5
32
5
18.1
2. After 45 hours
39.7
34
5
21.8
3. New Solution after 24 hours
22.1
15
4
7.8
Total Dissolved
62
49
9
30
(Sum of Lines 2 + 3)
[0032] A significant amount of the components are dissolved from the scale deposit after 21 hours, but lesser amounts are dissolved after 45 hours as compared to the first 21 hours. However, 24 hours after application of a fresh solution more components are dissolved from the scale deposit as compared to the previous 24 hours (between 21 and 45 hours).
EXAMPLE 4
[0033] The Solution F of Example 3 is compared to another sample made with the same composition, except without hydrogen peroxide, and by the same procedure according to Example 3. Both compositions are applied to the same amount of the scale deposit of Example 1 in the same manner. The results are depicted below:
[0000]
TABLE 4
Percent, By Weight, of the Dissolved Scale Deposit Iron and Sulfur
Fe
S
With Hydrogen Peroxide 21 hours
36.5
18.1
Without Hydrogen Peroxide 24 hours
6.0
0.2
[0034] Ammonium citrate without hydrogen peroxide dissolves a small amount of the scale deposit as compared to a composition including ammonium citrate and hydrogen peroxide. As depicted, including hydrogen peroxide with the ammonium citrate can dissolve greater amounts of iron and sulfur from a scale deposit.
EXAMPLE 5
[0035] The pH of the Solution F is measured during the first 21 hours of dissolving the scale deposit, as discussed in Example 3.
[0000]
TABLE 5
pH and Percent, By Weight, of the Dissolved
Scale Deposit Components
Time (Hr)
pH
Fe
Ni
Cr
S
0
5.18
—
—
—
—
1.25
5.01
7.9
15
0.7
6.1
2
5.05
12.4
15
0.7
5.8
4
5.09
20.6
19
1.2
7.7
6
5.16
27.5
22
1.2
10.1
21
7.2
36.5
32
5
18.1
[0036] The percent of dissolved scale is shown above as a function of time. After 6 hours the pH may change very little, while the dissolution of the scale deposit continues.
[0037] A composition including ammonium citrate and hydrogen peroxide can clean surfaces of scale deposits in processing equipment and vessels, such as a hot combined heat exchanger. Under suitable conditions, a scale deposit may dissolve iron and sulfur components at a rate of about 3 to about 4%, by weight per hour based on the total iron and sulfur present in the scale deposit. Although not wanting to be bound by theory, it is believed that the hydrogen peroxide can enable the oxidation of sulfide to sulfate, as evidenced by the drop in pH at the beginning of the treatment and the detection of sulfate in a solution. Fresh ammonium citrate solution can further dissolve components from the scale deposits as compared to a used solution possibly due to the limited solubility of iron citrate.
[0038] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
[0039] In the foregoing, all temperatures are set forth uncorrected in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.
[0040] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
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One exemplary embodiment can be a process for removing one or more scale deposits formed on a surface. The process can include contacting the surface with a composition for a period of time sufficient to remove the scale deposits that comprise coke or metal sulfides or mixtures thereof. Generally, the composition includes an effective amount of an organic acid and/or a salt thereof, and an effective amount of an oxidizing agent.
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BACKGROUND OF THE INVENTION
In the Bayer process for the extraction of alumina from bauxite, finely ground calcined bauxite is charged into a heated pressure vessel containing a solution of caustic soda of about 45% strength. With a properly calcined material, the alumina passes into solution as sodium aluminate. When solution is complete, a matter of some hours, the pressure is released from the vessel and the contents are discharged into a receiving vessel.
To handle the strong hot solution one or more valves are required in the piping arrangement. A common occurrence is for material to deposit upon the elements of a valve such that the valve may become locked or the seating surfaces on the valve and the valve's orifice may become encrusted with material from the caustic solution with the result that the valve may be held in an open position or locked in a closed position.
Many of the prior art valves used in such a system are well summarized in the patent to Crawford U.S. Pat. No. 4,177,825 of Dec. 11, 1979 which also deals with such a valve. Although the valve described in Crawford U.S. Pat. No. 4,177,825 performs in a satisfactory manner at low and medium pressures, at high pressures, i.e., at pressures in excess of about 250 psi, the axially disengaging clutch mechanism of this valve may not always be substantially immediately responsive and may not provide the desired release, particularly at pressures in the vicinity of about 600 psi which limits its operational range. In contrast to the Crawford valve, the valve of the instant invention, due to the use of a radial clutch mechanism, allows the use of this valve over the entire pressure range presently existing in the usual Bayer process alumina plants.
The valve of the present invention is of lower cost, more rugged and of a simpler design than the Crawford valve. The valve of the present invention utilizes a radial clutch which disengages the valve disc from the drive shaft when a predetermined torque (disc/seat friction) is exceeded. This is accomplished by the use of heavy leaf springs acting on pawls which engage the disc body, the pawl leaf spring assembly being mounted on a rotor keyed to the valve stem.
SUMMARY OF THE INVENTION
It is in general the broad object of the present invention to provide an improved valve construction which is particularly useful in the processing of an alumina containing caustic solution generated in the aforementioned Bayer process for the treatment of bauxite ores. In that process multiple pumping and valve controlled operations are utilized with the aforementioned buildup of hydrated alumina alkali or silica scale on the wetted surface of the valve elements, particularly the valve seats, usually necessitating extensive and expensive maintenance practices.
It is another object to provide a valve mechanism in which the valve disc is rotated relative to the valve seat to effect relative grinding as part of the normal closing operation. The rotary movement is controlled by a cam actuated clutch mechanism which interrupts the rotary movement of the valve disc when a preselected frictional force is encountered between the disc and seat. Further, the clutch mechanism disengages from the valve disc during the opening cycle so that no grinding takes place.
Another object is to provide such a valve in which the frictional force between the valve disc and seat may be adjusted for different grinding requirements.
A further object is to provide a self grinding valve mechanism which has particular utility with large valves, in the order of 600 lbs., and which are used in adverse environments, such as in the aforementioned Bayer process. The valve of the present invention has the features of having the valve stem carry the valve disc for positive axial movement therewith but to allow relative rotary movement. The rotary movement is controlled by a trip mechanism which is dependent on the sliding frictional forces between the disc and seat. The positive axial movement of the stem and associated disc assures positive closing of the valve and also facilitates opening the valve against the high operating system pressures encountered in such valves.
A still further object is to provide an operating nut for the stem that includes a compressible spring assembly which permits a limited free axial movement of the stem while maintaining a preselected reaction force on the seat and disc during the grinding operation. At the end of the free movement the axial motion of the nut is stopped and a positive stem movement closes the valve.
Another object of the invention is to provide such a valve which can function in adverse environments without operator assistance and which may be operated from a remote location. Similarly, the working parts of the valve are sealed and shielded from the slurry and the contacting seal and disc seat are formed of hardened material to assure long time, trouble free operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross section of a valve showing the best mode of carrying out the construction of my invention.
FIG. 2 is a section taken along the line 2--2 in FIG. 1.
FIG. 3 is a perspective view of the valve disc shown in seating relation with the valve seat.
FIG. 4 is a section taken along the line 4--4 showing details of construction of a clutch arrangement utilized in the seating.
FIG. 5 is an enlarged cross section of the valve seating arrangement showing details of the construction and particularly of the grinding elements provided upon the valve element in the valve seat and taken along the line 5--5 in FIG. 4.
FIG. 6 is an enlarged sectional view showing construction and operation of the release of the valve element.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The valve comprises a main body 11 having an inlet 12 defined by a flange 13 and an outlet 14 provided at an angle to the inlet 12. A seat 15 between the inlet and outlet cooperates with the valve closure element 16 to control the flow of material and fluid through the valve. Mounted upon the main body 11 is a bonnet 17 secured to the main body by stud and nut fasteners 18. The bonnet 17 includes a transverse flange 19 upon which is mounted a bearing 21 providing a slidable support for a sleeve 22 which extends upwardly from movable valve disc 16 through a stuffing gland generally indicated at 28 and having packing 29 provided about the sleeve 22. The packing gland is secured to flange 19 by several fasteners 31. The sleeve 22 fits snugly about the valve stem 41, the upper end of which is threaded as at 42 with a left hand thread. The lower end of the valve stem 41 is secured to the valve closure element 16.
The valve closure element 16 includes an annular seating face 43 cooperatively positioned with respect to annular seating face 44. In accordance with this invention, the surface of these two areas are coated with an extremely hard, well bonded, wear resistant coating. This material is applied by a unit designated by its manufacturer, Union Carbide Corporation, Linde Division, Coatings Service Department of Indianapolis, Ind. and known as a Detonation Gun. Union Carbide's description of the operation of this Gun is as follows:
"The D-Gun resembles a large-caliber machine gun. When measured quantities of oxygen, acetylene and particles of coating material are metered into the firing chamber, a timed spark detonates the mixture. This creates a hot, high-speed gas stream which instantly heats the particles to a plastic state and hurls them at supersonic velocity (2500 fps) from the gun barrel. The near molten particles impinge onto the surface of the workpiece where a microscopic welding action produces a tenacious bond. Rapid-fire detonations, during automatically controlled passes across the workpiece, build up the coating to a specified thickness. "
"Although temperatures above 6,000° F. are reached inside the gun, the workpiece remains below 300° F. Thus, metallurgical properties of the base material are not changed during the coating process. Low temperatures in the substrate also eliminate the possibility of warpage, distortion or other physical change in precision parts."
The particular material is designated by Union Carbide as LW-5 and comprises 73% tungsten carbide, 20% chromium and 7% nickel. Reference is made to U.S. Pat. Nos. 2,714,563 and 3,071,489 of Union Carbide Corporation.
Mounted on the upper end of the threaded portion of the valve stem 41 is an assembly provided as a nut structure generally indicated at 51 (see FIG. 2). The structure 51 includes an operating nut 52 having a threaded bore 53 for receiving threaded stem 41. Nut 52 is slidable axially within the bonnet along glides 54 held to the upper end of bonnet 17 by machine screws 56. Upward travel of nut 52 is limited by transverse stop element 57 secured to the upper end of bonnet 17. Depending from element 57 are four threaded rods 58 which support nut 52 through bores 59 and lower stop nuts 61. Springs 62 interposed between stop element 57 and spring retainer sockets 63 on operating nut 52 bias the nut toward the stop nuts 61, that is in the downward direction as viewed in FIG. 1. This arrangement allows limited axial movement of the nut between stop 57 and stop nuts 61 and therefore a similar movement of the stem 41 and closure element 16 as is conventionally used, such as in the aforementioned Crawford patent.
A spur gear 66 is secured on the upper end of the valve stem 41 by a nut structure 67. The spur gear is rotated by a pinion gear 68, the pinion gear being mounted on extension 69 on the upper end of the bonnet 17. Spur gear 66 is journaled for rotation in bearings 71 at the top of bonnet 17 and carries key 72 in longitudinal keyway 73 in threaded stem 41. Rotation of gear 66 turns threaded stem 41 and causes axial movement of the closure element 16 through the action of nut structure 51 and also causes rotational movement of closure element 16 through the action of clutch structure 77 as will be described hereinafter. Rotation of pinion gear 68 may be actuated by an electric or hydraulic motor 60 mounted on coupling 65 and controlled as from a remote location. Rotation of the gear 68 can also be effected by socket 70 in a well known manual manner. It should be appreciated that the force needed to operate the closing element is much reduced from prior similar valves, especially during the opening cycle, because of the unique features of the clutch structure 77.
Clutch structure 77 is operative to rotate the valve closure element 16 when the stem is turning in the direction of arrow 81 during the closing cycle. When the valve stem is opening (in the direction of arrow 82) the clutch elements disengage and this releases any torque force between the closing element 16 and seat 15. Thus the valve can be opened without overloading the system or the stem or actuator. The grinding is effected only upon rotation in one direction, specifically the closing direction and not in the opening direction during which the combined loads of disc/seat friction, calcined cementation and system pressure would have to be overcome.
Looking to FIGS. 3 through 6, clutch structure 77 is carried at the lower end of stem 41 between upper and lower members 78 and 79 of closure element 16. A rotor 81 is fixed to stem 41 through keys 82 and is axially positioned between shoulder 83 and lower cap plate 84. Thrust forces are transmitted between the closure element 16 and stem 41 and rotor assembly 81 through retaining nuts 86 and lower spherical surface 87 seated on pad 88. Annular ring 91 carried between upper and lower members 78 and 79 and affixed thereto by machine screws 92 forms a cavity 93 in which rotor 81 is free to turn. The inner surface of ring 91 has a cam profile 94 which includes an annular race 96 interrupted by three equidistantly spaced lugs 97. Each lug has an elongated sloping ramp 98 and an abrupt catch surface 99. Trip members 101 slidably carried equidistantly about rotor 81 in radial slots 102 are confined by upper plate 103 secured to rotor 81 by screws 104. The inner ends of trip members 101 have cylindrical faces 106 which contact leaf spring assemblies 107 to bias the trip members radially outward to ride along cam surface 94. The outer face of members 101 is profiled to compliment catch 99 on one face and is rounded on the other face.
As shown in FIGS. 4 and 6, spring assemblies 107 include a series of leaf springs 108 secured at one end by fixtures 109 in slots 111 of rotor 81 and having their distal ends free to bear on trip members 101. The spring force of spring assemblies 107 is chosen to cooperate with the springs 62 of upper traveling nut 51 as will be described hereinafter. It should be noted that the rotor, sliding trip members, cam surface and spring assemblies are carried in cavity 93 where they may be supplied with a proper lubricant and are isolated from the adverse effects of the slurry or other fluid flowing through valve 11. Similarly coil springs 62, bearing 71 and any hydraulic actuator are spaced on bonnet 17 away from the effects of the heated slurry.
In operation, during the closing cycle, stem 41 is rotated by the spur gear drive 66 and will move valve element 16 in a longitudinal path from the dotted line position in FIG. 1 toward the valve seat 15. As can best be seen in FIG. 1, nut 52 is not fixed but is restrained from rotation by bonnet-yoke 17, two guides 54, so that nut 52 will move upwardly when the reaction force between disc and body seats overcomes springs thrust 62. Thus, nut 52 can move from the position shown in solid lines to the position shown in phantom so that nut 52 moves upwardly closing the gap between transverse stop element 57 and nut 52 when the frictional force will trip overload clutch 81, 101, 107 and seat reaction thrust on spring 62 is overcome. Nut 52 will be in its lower position from the previous cycle and spring 62 extended. Trip members 101 will be extended by leaf spring assemblies 107 to confront catch 99 of cam surface 94 and cause element 16 to rotate. As hardened surface 43 contacts any calcified residue around the seat area 44, the friction between the valve disc 16 and valve seat will increase. This will cause nut 52 to move upward compressing springs 62 to keep a fairly constant axial force by the disc on the seat and will maintain this force during rotation of the disc during the grinding operation which should be about 11/2 revolutions. When the frictional force between the seat/disc becomes greater than the leaf spring force holding the trip members out, the trip members will move inward along lug 97 and disengage the rotor torque from sealing element 16. Continued stem rotation will further move nut 52 into contact with stop 57 at which time positive displacement of element 16 will occur and element 16 will be firmly seated. From the foregoing, it will be noted that it is the interplay between the forces of seal/disc frictional torque as defined by nut springs 62 and leaf springs 108 that determine the duration of the grinding cycle. Thus, when the valve is dry and the seal/disc frictional force is greater there is less grinding than when the seals are wetted. This overcomes the adverse effects of galling the seats by grinding them in the dry state which was a problem with current valves.
During the opening cycle, when stem 41 rotates, nut 52 will start to move downward and rotor 81 will rotate in cavity 93 but because trip members 101 now move along the elongated ramp portion 98 of the cam this rotary motion is not transmitted to element 16. At some point, either the force in the nut springs 62 will overcome the fluid system pressure or the nut will contact stop nuts 61 and stem 41 will move longitudinally upward to pull seal element 16 from seat 15. As mentioned earlier, since the disc is not rotating during the opening cycle the force needed to turn stem 41 is much reduced and the overall load on the entire system and actuator is greatly reduced over prior valves which is especially important in the larger size valves.
From the foregoing it will be seen that I have provided an improved self grinding valve in which the operative mechanism may work under preselected conditions of force and one-way operation which has particular utility for use under adverse conditions such as those found in the alumina industry.
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A valve structure is provided which can be opened and closed under operating conditions without any adjustment in conditions existing in the system in which the valve is an element. The valve element can be turned with respect to the seat to provide for proper relation between the valve element and the valve seat to grind one with respect to the other during the operating cycle. The valve also includes a clutch having a radial acting trip overload that prevents the valve seat from being damaged during grinding which is effected by turning the valve through the clutch while moving the valve toward the seat during the closing cycle and produces a controlled grinding operation independent of pressure within the valve.
When the valve is operated in the opposite direction, the clutch disengages and the actuator mechanism encounters only the thrust forces during the opening cycle. This allows the valve to be easily opened without overloading the system.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a reproducing apparatus, and more specifically, enlarging processing performed when encoded image data is reproduced.
[0003] 2. Related Background Art
[0004] Video cameras for picking up image data and recording the image data as digital signals on a magnetic tape, a memory card or the like to reproduce the image data have been around for some time. This type of apparatus records picked-up image data after encoding the image data by JPEG or other encoding methods.
[0005] Some video cameras have a function of enlarging, reducing or rotating reproduced image data to be displayed. For example, in enlarged display processing, image data reproduced from a recording medium is decoded and, a part of the decoded image data is extracted and enlarged to display a reproduced image enlarged.
[0006] In a known structure, decoded image data is stored in a memory and a part of the stored image data, corresponding to a designated area of the memory, is read out to be subjected to enlarging processing (see for example Japanese Patent Application Laid-open No. H09-44130 (corresponding U.S. Pat. No. 5,999,161)).
[0007] The structure disclosed in Japanese Patent Application Laid-open No. H09-44130 needs to decode all of reproduced image data and store in a memory in order to display an enlarged image.
[0008] This raises the frequency of access to the memory and, accordingly, the memory has to be accessible at high speed. The structure thus poses a problem by increasing cost and power consumption of the video camera or similar apparatus.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to solve the above-mentioned problem.
[0010] Another object of the present invention is to provide an apparatus that requires less frequent access to a memory and consumes less power during enlarging processing of encoded image data.
[0011] To achieve the above objects, according to one aspect of the present invention, a reproducing apparatus of the present invention comprises: reproducing means for reproducing, from a recording medium, moving image data including plural frames whose information amount has been compressed by intraframe encoding; a memory for storing the moving image data reproduced by the reproducing means; decoding means for read out the frames of the moving image data from the memory and decoding the read-out data, the decoding means reading out the moving image data in succession starting from an upper end of a screen for each frame to decode the read-out moving image data; instruction means for instructing to enlarge the moving image data; enlarging area setting means for setting, for each frame of the moving image data, a partial area on which enlarging processing is to be performed; control means for controlling the decoding means in accordance with the enlarging instruction given by the instruction means, the control means stopping reading out the one frame of moving image data from the memory, which is performed by the decoding means, in case that moving image data of the partial area in the one frame of the moving image data is decoded; and output means for modifying, in accordance with the number of pixels of the display device, the moving image data of the partial area decoded by the decoding means, and outputting the modified image data to the display device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Other objects and characteristics of the present invention than those mentioned above will become more apparent by the following detailed description of embodiments when read in conjunction with the accompanying drawings in which:
[0013] FIG. 1 is a block diagram showing the schematic structure of an embodiment of the present invention;
[0014] FIG. 2 is a flow chart showing the flow of displaying operation according to the embodiment;
[0015] FIG. 3 is a detailed flow chart of a stop mode (S 6 );
[0016] FIGS. 4A, 4B and 4 C are diagrams showing display examples according to the embodiment; and
[0017] FIG. 5 is a diagram showing the order of reading image data from a memory in encoding and decoding processing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] A detailed description will be given below on an embodiment of the present invention with reference to the accompanying drawings.
[0019] FIG. 1 is a block diagram showing the system structure of an image pickup apparatus according to this embodiment.
[0020] The image pickup apparatus of FIG. 1 is capable of picking up and recording moving image data that is made up of 30 frames of image data per second as well as reproducing a recorded moving image. The apparatus can take still pictures in addition to moving images.
[0021] A Central Processing Unit (CPU) 100 controls the entire image pickup apparatus. Denoted by 101 is an interface circuit (I/F) for the CPU 100 , 102 denotes a recording medium such as a memory card, and 103 denotes an interface circuit (I/F) for the recording medium 102 . Reference numeral 106 denotes a Dynamic Random Access Memory (DRAM) where image data, program and the like are stored. Reference numeral 104 denotes a system controller, which is engaged in sequential control, bus arbitration control, and the like. Reference numeral 107 denotes an image pickup lens, and 108 denotes an image pickup element composed of a one-chip Charge-Coupled Device (CCD).
[0022] Denoted by 109 is an A/D conversion circuit to convert an analog signal into a digital signal. Reference numeral 110 denotes a signal processing circuit and 111 , a magnification circuit to reduce or enlarge image data in a horizontal or vertical direction through thinning-out processing, linear interpolation processing, or the like. Reference numeral 112 denotes a raster-block conversion circuit, which converts raster scan image data magnified by the magnification circuit 111 into block scan image data. Denoted by 113 is a buffer memory for raster-block conversion. The memory 113 is used to convert raster data into block scan data. Reference numeral 114 denotes a compression circuit, which employs JPEG to encode image data outputted block by block from the raster-block conversion circuit 112 and to thereby compress the amount of the data.
[0023] When a moving image is picked up, the raster-block conversion circuit 112 denotes frames of moving image data that are in raster scan order into an order of blocks having predetermined number of pixels in length and width, and outputs the converted data. The compression circuit 114 encodes, when a moving image is picked up, frames of image data outputted from the raster-block conversion circuit 112 by JPEG. JPEG is, as well known, an intraframe encoding method which encodes image data are using only image data in the same frame.
[0024] The raster-block conversion circuit 112 at this point reads out frames of image data stored in the buffer memory 113 starting from a block 501 , which is located at the upper left corner of the screen as shown in FIG. 5 . The raster-block conversion circuit 112 next reads out the block to the right of the block 501 on the screen, and then continues on in this way until the rightmost block on the screen is reached. After the rightmost block is read out, blocks immediately below the current row of blocks are read out in a similar manner starting from the leftmost block.
[0025] A memory control circuit 105 transfers, during recording, by DMA transfer, image data outputted from the compression circuit 114 to the DRAM 106 , and transfers image data stored in the DRAM 106 via the system controller 104 and the I/F 103 to the recording medium 102 , where the transferred image is recorded. When image data is to be reproduced, the memory control circuit 105 reads out compressed image data from the recording medium 102 , transfers, by DMA transfer, the read data to the DRAM 106 via the interface circuit 103 and the system controller 104 , and transfers, by DMA transfer, the image data in the DRAM 106 to a reproduction circuit 121 , which will be described later.
[0026] The CPU 100 uses a predetermined program to create decoded image data through software processing in which JPEG-encoded image data is decoded. The CPU 100 performs thinning-out processing and linear interpolation processing to reduce and enlarge, respectively, a decoded image.
[0027] The reproduction circuit 121 performs modulation, addition of synchronized signals, digital/analog conversion and the like on image data that is reproduced from the recording medium 102 and decoded, to thereby convert the reproduced and decoded data into a form suitable for display on a monitor 122 .
[0028] The number of pixels of an image that can be outputted to and displayed on the liquid crystal monitor 122 , which serves as a display unit, is smaller than the number of pixels of the image pickup element.
[0029] Denoted by 123 is an operation unit, which is composed of a switch SPLAY, a switch SFWD, a switch SREV, a switch SZUP, a switch SZDOWN, and a switch SSTOP. Denoted by 124 is a four-way operational key composed of a switch SUP, a switch SDOWN, a switch SRIGHT, and a switch SLEFT.
[0030] The functions of the switches of the operation unit 123 will be described. The switch SPLAY is a switch used to command that an image be played. When the switch SPLAY is turned on, an image recorded on the recording medium 102 is displayed on the liquid crystal monitor.
[0031] The switch SFWD is a switch for playing one still image ahead, and the switch SREV is a switch for playing one still image back.
[0032] The switch SZUP is a switch used to command the apparatus to enlarge an image being played, and the switch SZDOWN is a switch used to command the apparatus to reduce in size an image being played.
[0033] The switch SSTOP is a switch used to command the apparatus to pause a moving image that is being played. Each time the switch SSTOP is operated, one of an instruction to resume playing a moving image and an instruction to pause playing is outputted in an alternating manner.
[0034] The switch SUP, the switch SDOWN, the switch SRIGHT and the switch SLEFT correspond to the upper, lower, right and left portions of the four-way operational key 124 , respectively. The four-way operational key 124 is, as will be described later, effective when a reproduced image is displayed enlarged. The switch SUP is a switch used to command the apparatus to scroll up over an enlarged image, the switch SDOWN is a switch used to command the apparatus to scroll down, the switch SRIGHT is a switch used to command the apparatus to scroll to the right, and the switch SLEFT is a switch used to command the apparatus to scroll to the left.
[0035] FIGS. 4A to 4 C are diagrams showing a reproduced image and how the image is displayed on the monitor. FIG. 4A shows frames of a moving image before the image is enlarged and displayed. FIG. 4B shows areas of the moving image data of FIG. 4A that are decoded and stored in the DRAM 106 to extract and enlarge a part of each frame of the moving image data. FIG. 4C shows the screen of the monitor 112 which is displayed when the monitor 112 displays the moving image of FIG. 4A .
[0036] Described next with reference to FIGS. 2 and 3 is processing for playing a moving image.
[0037] In this embodiment, a frame of moving image data before encoded has an aspect ratio of 4:3, and 1280 pixels (h)×960 (v). Such moving image data is reproduced from the recording medium 102 and is displayed on the monitor 122 , which has a resolution of 640 pixels (h)×480 pixels (v). As has been described, each frame of moving image data is encoded by JPEG and, to reproduce the moving image data, data of a frame is decoded by JPEG separately from data of another frame.
[0038] The CPU 100 goes into a play mode when it is detected that the switch SPLAY has been turned on. In step S 201 , the CPU 100 controls the interface circuit 103 and the system controller 104 to start reading out a desired moving image file from of the recording medium 102 . The image data read out from the recording medium 102 is transferred to and stored in the DRAM 106 in order.
[0039] In step S 202 , the display magnification is initialized and ×1 display magnification is set to display the whole image on the monitor 122 .
[0040] In step S 203 , the CPU 100 sets a still image stored at the head of the moving image file, and starts a timer set in accordance with a desired frame rate.
[0041] In step S 204 , a state of the switch SPLAY is judged. When the switch SPLAY is off, the CPU 100 ends the play mode whereas the play mode is maintained and the CPU 100 moves to the next step when the switch SPLAY is on.
[0042] In step S 205 , a state of the switch SSTOP is judged. When the switch SSTOP is on, the CPU 100 pauses playing a moving image and moves to step S 206 . When the switch SSTOP is off, the moving image is kept played and the CPU 100 moves to the next step. Stop mode processing in step S 206 will be described later.
[0043] In step S 207 , states of the zoom switches SZUP and SZDOWN, which are used to specify a display magnification, are judged. As a user operates either one of the zoom switches, the CPU 100 moves to step S 208 . In the case where neither of the switches SZUP and SZDOWN is operated, the CPU moves to step S 217 .
[0044] In step S 217 , whether the display magnification is ×1 magnification or not is judged. When an image is displayed enlarged, the CPU 100 moves to step S 218 , and to step S 220 when the display magnification is ×1 magnification.
[0045] In step S 220 , the display magnification is set to ×1. In step S 221 , the original image size, namely, 1280 pixels (h)×960 pixels (v), is set as the size in which the image data is to be read out from the DRAM 106 in accordance with the display magnification set in step S 220 .
[0046] In step S 222 , the CPU 100 sequentially reads out, via the memory control circuit 105 , from the DRAM 106 , image data in the head frame of the moving image file set in step S 203 , and decodes the read image data. The decoded image data is sequentially written in the DRAM 106 block by block via the memory control circuit 105 .
[0047] In step S 223 , whether decoding processing has been completed for one frame of image data or not is checked. In the case where decoding processing for one frame of image data has been completed, the CPU 100 moves to step S 224 .
[0048] In step S 224 , the CPU 100 changes the resolution of decoded image data from the original image size to the resolution of the monitor 122 .
[0049] Specifically, the CPU 100 reads out stored image data from the DRAM 106 via the memory control circuit 105 and converts the resolution of the image data. When the display magnification is ×1, the original image size, 1280 pixels (h)×960 pixels (v), is reduced by ½ in width and by ½ in height. The converted image data is sequentially written in a display area in the DRAM 106 . Thus 640 pixels (h)×480 pixels (v) image data for display is stored in the DRAM 106 . The stored image data is displayed as shown in screens 60 and 61 of FIG. 4C .
[0050] In step S 214 , whether the frame that is currently displayed is the last frame of the moving image data or not is judged. In the case where it is the last frame, the moving image play mode is ended. In the case where it is not the last frame, the CPU 100 moves to step S 215 .
[0051] In step S 215 , which frame is to receive reproduction processing next is set.
[0052] In step S 216 , the timer set in step S 203 is checked to determine whether a predetermined period of time has passed or not. In the case where the predetermined time has passed, the CPU 100 proceeds to processing the next frame of the image data.
[0053] Subsequently, steps S 204 to S 216 are repeated.
[0054] Described next is the operation of displaying a moving image that is being played enlarged. A user operates the switch SZUP for enlarged display while a moving image is being played at ×1 magnification. Then the CPU 100 judges in step S 207 that the switch SZUP has been operated, and moves to step S 208 .
[0055] In step S 208 , a larger magnification is set each time the user operates the switch SZUP (to ×2 at one flick of the switch SZUP, ×4 at the next flick) whereas a smaller magnification is set each time the user operates the switch SZDOWN (to ×2 at one flick of the switch SZDOWN, ×1 at the next flick). In this embodiment, the display magnification is changed to ×2 by operating the switch SZUP while a moving image is being displayed at ×1 magnification.
[0056] In this embodiment, an area of the original image is extracted in accordance with the enlarging magnification, and the extracted portion of image data is subjected to enlarging processing in accordance with the number of pixels of the monitor 122 .
[0057] In step S 209 , the size of the area to be extracted is obtained from the original image size and the magnification set in step S 208 , to set a range to be extracted for enlarged display on the original screen.
[0058] For instance, when the display magnification set in step S 208 is ×2, the size of the extracted area is set to 640 pixels (h)×960 pixels (v) by multiplying 1280 pixels×960 pixels by ½ in width and length, respectively. Similarly, the display magnification set in step S 208 is ×4, the size of the extracted area is set to 320 pixels (h)×240 pixels (v) by multiplying the original image size by ¼ in width and length, respectively. Here, the display magnification set in step S 208 is 2.
[0059] In step S 210 , the CPU 100 reads out one frame of stored image data from the DRAM 106 via the memory control circuit 105 , and decodes the read-out image data block by block. At this point, the CPU 100 sequentially reads out one frame of image data stored in the DRAM 106 starting from a block at the upper left corner of the screen as shown in FIG. 5 , and decodes the read-out image data. The decoded image data is sequentially transferred to and stored in the DRAM 106 via the memory control circuit 105 .
[0060] After decoding processing is started in order from the upper left corner block on the screen in this way, the CPU 100 compares in step S 211 the position on the screen of the decoded image data against the extraction range set in step S 209 . The CPU 100 continues the processing of reading out encoded image data from the DRAM 106 and the processing of decoding the read-out image data until the position of the decoded image data exceeds the extraction range. When it is judged that the extraction range is exceeded, the CPU 100 moves to step S 212 .
[0061] In step S 212 , the processing of decoding encoded image data is stopped. As a result, the DRAM 106 now stores image data of the range shown in 52 of FIG. 4B in a decoded state whereas image data of an area below this range on the screen remains encoded. In FIG. 4B, 520 indicates the extraction range set in step S 209 .
[0062] In step S 213 , the CPU 100 converts the resolution of the image data in the extracted area set in step S 209 into the resolution of the monitor 122 .
[0063] In other words, the CPU 100 has the memory control circuit 105 read out image data of an extraction area, specifically, image data in the extraction range 520 of FIG. 4B , from the DRAM 106 , and converts the resolution of the read image data into the resolution of the monitor 122 in accordance with a set display magnification.
[0064] For instance, when the display magnification is ×4, image data of 320 pixels (h)×240 pixels (v) extraction area is doubled in the horizontal direction and the vertical direction each. When the display magnification is ×2, there is no need to convert the resolution and the image data is displayed as it is since the size of the extraction range is 640 pixels (h)×480 pixels (v).
[0065] The image data with the resolution thus converted is written in a display memory area of the DRAM 106 in order. In this way, enlarged image data having 640 pixels (h)×480 pixels (v) is stored in the display memory area of the DRAM 106 , and the stored image data is displayed as a×2 magnification image on the monitor as shown in a screen 62 of FIG. 4C .
[0066] Subsequently, steps S 214 to S 207 are repeated to set the next frame.
[0067] In the case where the switches SZUP and SZDOWN are found to be off in step S 207 , the CPU 100 moves to step S 217 .
[0068] In step S 217 , the display magnification is checked to judge whether it is ×1 magnification or not. When the display magnification is judged to be larger than ×1 magnification, the CPU 100 moves to step S 218 . When the display magnification is judged as ×1 magnification, the CPU 100 moves to step S 220 .
[0069] In step S 218 , the CPU 100 judges states of the switches SUP, SDOWN, SRIGHT and SLEFT of the four-way operational key 124 . When the user operates any one of the four switches to instruct the apparatus to change the display position, the CPU 100 moves to step S 219 . When none of the switches SUP, SDOWN, SRIGHT and SLEFT is operated, the CPU 100 moves to step S 210 . In the case where the four-way operational key is not operated while the screen 62 of FIG. 4C is displayed, a screen 63 is displayed without changing the current display range.
[0070] Subsequently, steps S 210 to 218 are repeated to display the continuous frames 62 and 63 of a moving image enlarged.
[0071] On the other hand, when the user operates the four-way operational key 124 to change the display position while a moving image is being played enlarged, the CPU 100 checks the states of the switches SUP, SDOWN, SRIGHT and SLEFT and moves to step S 219 . In step S 219 , the CPU 100 sets a new area to be extracted for enlarged display in a direction that is designated via the switches.
[0072] For example, in the case where the switch SLEFT is operated while a screen 53 of FIG. 4B is displayed, the extraction range is moved to the left of the range 530 to set a new extraction range 540 . As a result, the display screen of the monitor 122 is switched to a screen 64 of FIG. 4C .
[0073] Subsequently, steps S 210 to S 213 are repeated.
[0074] Pausing processing will be described next.
[0075] The user operates the switch SSTOP in step S 205 to pause a moving image that is being played enlarged. This causes the CPU 100 to move into a stop mode where playing of a moving image is paused. FIG. 3 is a flow chart showing processing of the stop mode in step S 206 .
[0076] In step S 301 , the CPU 100 initializes display settings and sets a parameter Disp to 0. In step S 302 , the CPU 100 reads out one frame of image data stored in the DRAM 106 via the memory control circuit 105 , and decodes the read-out image data in order. The decoded image data is sequentially transferred to and stored in the DRAM 106 via the memory control circuit 105 .
[0077] In step S 303 , completion of decoding one frame of image data is waited. Image data stored at this point in the DRAM 106 is as shown in a screen 55 of FIG. 4B . In other words, when instructed to pause playing, the CPU 100 decodes all of image data of one frame, including an area of image data below the extraction range 550 for enlarged display, and stores the decoded image data in the DRAM 106 .
[0078] When decoding one frame of image data is completed, the CPU 100 judges in step S 304 states the zoom switches SZUP and SZDOWN, which are used to specify a display magnification.
[0079] In the case where the user operates either one of the zoom switches, the CPU 100 moves to step S 305 . In the case where the user operates neither the switch SZUP nor the switch SZDOWN, the CPU 100 moves to step S 310 .
[0080] In step S 310 , the state of the display magnification is judged. When the display magnification is judged to be larger than ×1 magnification, the CPU 100 moves to step S 311 . When the display magnification is judged as ×1 magnification, the CPU 100 moves to step S 314 .
[0081] In step S 311 , the CPU 100 judges the states of the switches SUP, SDOWN, SRIGHT and SLEFT of the four-way operational key 124 . When the user operates any one of the four switches to instruct the apparatus to shift the display range, the CPU 100 moves to step S 313 . When none of the switches SUP, SDOWN, SRIGHT and SLEFT is operated, the CPU 100 moves to step S 312 .
[0082] In step S 312 , the value of the variable Disp is checked. When it is judged that a still image is being displayed at a pause command (Disp=1), the CPU 100 moves to step S 309 . On the other hand, when it is judged that a moving image, not a still image, is being displayed (Disp=0), the CPU 100 moves to step S 307 .
[0083] In step S 307 , the CPU 100 converts the resolution of image data in the extraction range that is stored in the DRAM 106 , in accordance with the resolution of the monitor 122 .
[0084] In other words, of image data stored in the DRAM 106 , the CPU 100 reads image data in the extraction range and converts the resolution of the read image data in accordance with a set display magnification. For instance, when the display magnification is ×4, 320 pixels (h)×240 pixels (v) extraction range image data is doubled in the horizontal direction and the vertical direction each. When the display magnification is ×2, the 640 pixels (h)×480 pixels (v) extraction range image data is outputted as it is.
[0085] The converted data is written in a display memory area of the DRAM 106 in order. Thus 640 pixels (h)×480 pixels (v) image data is stored in the display memory area of the DRAM 106 . While the pause playing command is effective, the one frame of moving image data stored in the display memory area is repeatedly read out and outputted to the monitor 122 , to thereby display an enlarged image as a still image as shown in a screen 65 of FIG. 4C .
[0086] In step S 308 , the parameter Disp indicating whether a moving image or a still image is being displayed is set to 1.
[0087] In the case where the user operates the switch SSTOP in step S 309 in order to cancel the pause command while playing is paused, the CPU 100 ends the stop mode to resume playing a moving image in response. When the SSTOP is off, the CPU 100 moves to step S 304 .
[0088] When it is judged in step S 310 that the display magnification is ×1 magnification, the original image size, namely, 1280 pixels (h)×960 pixels (v), is set in step S 314 as a size in which image data is read out from the DRAM 106 .
[0089] In step S 315 , the CPU 100 converts the resolution of the decoded image data from the original image size to the resolution of the monitor 122 . Then the CPU 100 sets the parameter Disp to 1 and moves to step S 309 .
[0090] In the case where an instruction made by the user to change the display position is detected by detecting in step S 311 that any one of the switches SUP, SDOWN, SRIGHT and SLEFT of the four-way operational key 124 has been operated, the CPU 100 moves to step S 313 .
[0091] In step S 313 , the CPU 100 sets moves the extraction range in a direction designated through the four-way operational key 124 . Specifically, in the case where the switch SRIGHT is operated while the screen 65 of FIG. 4C is displayed, the extraction range is changed from 550 of FIG. 4B to 560 , with the result that a screen 66 of FIG. 4C is displayed on the monitor 122 . During the change, the monitor 122 keeps displaying a still image.
[0092] As has been described, according to this embodiment, one frame of encoded image data stored in the DRAM 106 is read out and decoded sequentially starting from an upper end of the screen in response to an enlargement command given while a moving image is played. As image data in an extraction range necessary in enlarged display is decoded, processing of reading out encoded image data from the DRAM 106 is ended, and decoding processing on this frame is stopped to proceed to processing of the next frame.
[0093] In this way, there is no need to read out a portion of encoded image data that is unnecessary for enlarged display, from the DRAM 106 , and to process decoding on this portion. Accordingly, the DRAM is accessed less frequently and the load of the CPU is thus lightened.
[0094] In addition, an enlarged play function can be obtained without increasing the load of the CPU even when the number of pixels per frame is increased, and at the same time, the power consumption can be reduced. Another technological advantage of this embodiment is improved ease of use in pausing an enlarged moving image since the display position can be moved as processing of expanding a still image is completed.
[0095] The above embodiment describes a case of playing a moving image, but similar processing can be performed when a still image is to be played.
[0096] The expansion processing and magnification processing of a still image, which are performed by the CPU in the above-described example, may be carried out by hardware.
[0097] The object of the present invention can also be achieved by providing a storage medium storing program codes for performing the aforesaid processes to a reproduction apparatus, reading out the program codes, by a CPU or MPU of the reproduction apparatus, from the storage medium, then executing the program.
[0098] In this case, the program codes read out from the storage medium realize the functions according to the embodiments, and the storage medium storing the program codes constitutes the invention.
[0099] Further, the storage medium, such as a floppy disk, a hard disk, an optical disk, a magneto-optical disk, CD-ROM, CD-R, a magnetic tape, a non-volatile type memory card, and ROM, and computer network, such as LAN (local area network) and WAN (wide area network), can be used for providing the program codes.
[0100] Furthermore, besides aforesaid functions according to the above embodiments are realized by executing the program codes which are read out by a CPU from the reproduction apparatus, the present invention includes a case where an OS (operating system) or the like working on the computer performs a part or entire processes in accordance with designations of the program codes and realizes functions according to the above embodiments.
[0101] Furthermore, the present invention also includes a case where, after the program codes read from the storage medium are written in a function expansion card which is inserted into the reproduction apparatus or in a memory provided in a function expansion unit which is connected to the reproduction apparatus, CPU or the like contained in the function expansion card or unit performs a part or entire process in accordance with designations of the program codes and realizes functions of the above embodiments.
[0102] In a case where the present invention is applied to the aforesaid storage medium, the storage medium stores program codes corresponding to the flowchart of FIGS. 2 and 3 described in the embodiments.
[0103] The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore to apprise the public of the scope of the present invention, the following claims are made.
[0104] This application claims priority from Japanese Patent Application No. 2004-213788 filed Jul. 22, 2004, which is hereby incorporated by reference herein.
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A reproducing apparatus includes: a reproducing portion for reproducing, from a recording medium, moving image data including plural frames whose information amount has been compressed by intraframe encoding; a memory for storing the moving image data reproduced by the reproducing portion; a decoding portion for reading out the frames of the moving image data stored in the memory and decoding the read-out data, the decoding portion reading out the moving image data in succession starting from an upper end of a screen for each frame to decode the read-out moving image data; an instruction portion for instructing enlargement of the moving image data; an enlarging area setting portion for setting, for each frame of the moving image data, a partial area on which enlarging processing is to be performed; a control portion for controlling the decoding portion in accordance with the enlarging instruction, the control portion stopping reading out the one frame of moving image data from the memory, which is performed by the decoding portion, in case that moving image data of the partial area in the one frame of the moving image data is decoded; and an output portion for modifying, in accordance with the number of pixels of the display device, the moving image data of the partial area decoded, and outputting the modified image data to the display device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to tie down devices, and, more particularly, to an improved lockable, tie down strap for hard-to-lock down loads, having no locking passage or element therein.
2. Description of Related Art
When storing or transporting valuable items or loads in or on boats, pallets, racks, shelves, vehicles, or the like, the item or load is often secured in place by a bungie cord, rope, strap, or the like. In addition, if the item or load is left unattended over a periods time, some type of locking mechanism, such as a cable lock or padlock, is used in an attempt to lock the item or load and prevent theft. Items or loads held in racks mounted on the tops of vehicles, such as surfboards and the like, are particularly susceptible to theft and should utilize some type of easily used and available locking tie down device, to prevent theft.
Many prior art locking systems and tie down devices are known. However, these known devices are not cost effective, nor are they particularly effective in providing security from theft for substantially all types of valuable items or loads. For example, many valuable items or loads do not have an opening or holding portion through which a cable or padlock can pass to lock down such item or load. Therefore, if a cable or lock is used to restrain an item or load, the item or load may be easily removed or stolen by merely loosening or shifting the cable or lock. Therefore, specifically designed locking assemblies, which are only designed to work with special fittings or the like, must be used if particular equipment or loads are to be locked down. These specifically designed locking assemblies tend to be expensive and complicated, and limited in use.
For example, it can be difficult to effectively lock a canoe, inflatable raft, kayak, small boat, surfboard, water skis or windsurfing equipment and the like, to a roof rack of a vehicle, without using such complicated, expensive tie down systems or racks with built-in locking arrangements. The known locking systems for racks or other holding assemblies are often inconvenient and/or hard to use. Therefore, persons in a hurry, or who are not handy, tend to forego engaging such locking devices or systems, and merely loosely tie down valuable items or loads, such as water sports equipment. As a result, such items are often lost, stolen, or used without permission.
Examples of known prior art locking devices and tie down systems are shown in U.S. Pat. Nos. D365,236 to Stockwell, 715,948 to Beveridge, 3,831,976 to Iden, Sr., 4,340,376 to Williams, 4,526,125 to Bain, Jr., 4,685,315 to Comolli, 4,712,394 to Bull, 4,860,408 to Johnson, 4,918,790 to Cirket et al., 4,938,040 to Humphreys, Jr., 4,951,365 to Loyd, 5,095,722 to Chapmond et al., 5,193,368 to Ling, 5,387,183 to Jones, 5,243,710 to Craycroft, 5,582,044 to Bolich and 5,706,680 to Wroble. These prior art devices and locking systems use different types of straps, which may be secured by easily taken apart hook and loop systems, buckles, or the like. Some of these devices or systems may have locks inserted in openings therein. Additionally, these known prior art patents disclose specifically designed locking devices for surfboards, kayaks and the like, which are limited in use since they must pass through openings in the item to be protected, or clamped to a portion of the equipment, such as to a fin of a surfboard.
U.S. Pat. No. 4,685,315 to Comolli shows a strap lock to hold suitcases, bags or the like together. This strap includes a lock that is used to lock the strap after the strap is wrapped around a bag. The lock must be opened before the strap may be removed from the suitcase or bag. However, neither Comolli nor any of the above-mentioned prior art locking systems and/or tie downs are adaptable to be used to easily and quickly hold and lock various size items and loads to a vehicle, or other support system, to prevent theft. Furthermore, none of the known prior art suggests the provision of strengthening means in the tie down strap itself.
Therefore, there exists a need in the art for a lockable tie down strap, adapted to be used with substantially any load, and which includes reinforcing elements in the strap. Furthermore, there exists a need for a tie down strap having a high strength cam-type lockable holding buckle, attached to a reinforced strap, which is used to lock down loads and which may not be removed without destroying the high-strength lock and/or cutting the reinforced tie down straps.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide an improved and simplified lockable tie down strap. It is a particular object of the present invention to provide an improved lockable tie down strap having a reinforcing means within the strap. It is a still more particular object of the present invention to provide an improved lockable tie down strap, which includes a high-strength lock that is simple in construction and in use, but which provides an effective securing and locking means for securing a load to a supporting surface. It is yet another particular object of the present invention to provide an improved lockable tie down strap having a key-operated, high-strength locking system in a cam-operated buckle having means therein to hold and lock a loose end of the tie down strap in a position cinched around a load. And, it is still another particular object of the present invention to provide a method for strapping down and securing loads in a locked position on a supporting surface, such as a roof rack, a shelf, or the like.
These and other objects and advantages of the present invention are achieved by providing a lockable, tie down strap having a separate reinforcing means in the strap, together with a locking cam-operated buckle secured to the reinforced strap to lock down substantially any size or shaped load to substantially any supporting surface. The present invention also provides a method of tying down and locking a load to substantially any holding surface, by utilizing a reinforced nylon, polyester, polypropelene, and the like, tubular webbing and a steel, cam-lockable buckle.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, wherein:
FIG. 1 is a partial top plan view of a tie down strap and cam-operated, lockable buckle of the present invention;
FIG. 2 is a cross sectional view taken along line 2 — 2 of FIG. 1;
FIG. 3 is a top plan view of a vehicle, supporting a kayak thereon, and utilizing a plurality of lockable tie down straps of the present invention to secure the kayak to a roof rack of the vehicle;
FIG. 4 is a side elevational view of FIG. 3;
FIG. 5 is a schematic cross-sectional representation of a surfboard secured to an adjustable roof rack, by a third embodiment of a lockable tie down strap of the present invention;
FIG. 6 is an enlarged, partial sectional side view of FIG. 4, showing one of the lockable tie down straps holding the kayak in position;
FIG. 7 is a top plan view of a cargo tray, having a load, such as a sports bag, held therein and secured in position by a pair of lockable tie down straps of the present invention, inserted through the tray and around the tray supporting elements; and
FIG. 8 is a front elevational view of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide for an improved, easy to assemble and use high strength, lockable tie down strap, generally indicated by the numeral 10 .
Turning now to the drawings, there shown are various embodiments of a lockable tie down strap of the present invention, illustrating its use as a multi-purpose utility strap for securing various sized and shaped items or loads to a boat, pallet, shelf, vehicle, or the like. The locking tie down straps of the present invention may be used to save time in securing and locking in position, items including, but not limited to, canoes, kayaks, small boats, rafts, surfboards, water skis, wake boards, wind surfboards, backpacks, luggage, sleeping bags, duffel bags, coolers, tents, dinghies, small boats to davits, batteries, fuel tanks, water toys, boat covers, boat to trailer, lumber, pipe, windows, ladders, tool chests, crates, trunks, televisions, stereo equipment and computers.
Turning now to FIGS. 1-4 and 6 , the lockable tie down strap 10 is shown as being comprised of a buckle 12 and an elongated strap 14 secured at first and second ends 16 , 18 in the buckle 12 . The first end 16 of the strap 14 is permanently held around a pin 20 at one end of the buckle 12 , by securing the strap 14 together at 22 , as by sewing or stitching. The second or loose end 18 of the strap 14 is inserted in and threaded around a second pin 24 , at another or second end of the buckle 12 . The end 18 is cinched or pulled to a desired tension or tightness around a load, and then locked in place in the buckle 12 by a gripping, locking, or serrated end 26 of a cam-operated element 28 , as described more fully below. The buckle and its components are preferably made from a high strength material, such as steel, or the like. The tie down strap 14 is preferably reinforced by means 30 , such as a flat metal wire braid, held in a plastic-coated strap. Or, preferably, the tie down strap 14 is made from a regular belting material, such as a textile, nylon, polyester, polypropelene, or the like, to make a tubular webbing, with a plurality of metal strands 30 , made from steel, or the like, held or woven into the material, to add greater tensile strength. The reinforcing material 30 prevents cutting of the strap material 14 from the buckle 12 by a knife or other cutting implement, to greatly improve its theft resistance.
As best shown in FIG. 2, the steel buckle 12 includes the reinforced strap 14 permanently coupled to the first end 20 , with the other or loose end 18 inserted and releasably held around the pin 24 . A key operated lock 34 is mounted in the cam-operated portion 28 , between two side plates 35 , and is movable to an open position, in the direction of the arrow 36 (see FIG. 1 ), when a key is inserted therein and turned, so as to turn a locking plate 37 to release it from a further locking plate held within a locking compartment 32 , defined by the side plates 35 and a bottom plate 38 . Upon being unlocked, the end 18 of strap 14 may be released from the serrated gripping or locking end 26 of the cam element 28 by pressing on a handle or tongue end 40 so as to rotate the cam element 28 , in the direction of the arrow 41 , against the bias of a spring 42 , held in compartment 32 around a pin 44 . The cam element 28 is rotatably mounted in the locking compartment 32 , on a pivot 46 .
Turning now to FIGS. 3, 4 and 6 , there shown is a vehicle 48 having roof racks 50 with a kayak 52 secured thereon by a pair of lockable tie down straps 10 of the present invention wrapped around the roof rack. A second embodiment of the lockable tie down strap is shown at 39 , for use in locking the front of the kayak 52 to a bumper 43 of the vehicle 48 . The lockable tie down strap 39 includes a first looped end strap 45 , secured to a buckle 12 and hooked or looped over one end of the kayak 52 . A second strap 47 is removably secured by a free end 49 in the lock 12 , and a hook end 51 , hooked on the bumper 43 .
Each of the reinforced straps 14 , used to tie down the kayak 52 , have the buckles 12 and free ends 18 passed under opposite ends of each of the racks 50 . The buckles 12 and free ends 18 are then pulled to the top of the kayak 52 , with the free ends 18 further passing under the other end of each rack 50 , on the opposite side of the kayak. The free ends 18 are then brought back to the top of the kayak where the loose ends 18 are inserted into the buckles 12 . The buckles 12 are locked by their key-operated locks 34 , after the loose ends 18 have been inserted and pulled taught where they are securely held in position by cooperating ends 26 of cam elements 28 .
Turning now to FIG. 5, there shown is a third embodiment of the lockable tie down strap of the present invention, generally indicated by the numeral 54 . In this embodiment, the tie down 54 is shown being used to lock a surfboard 56 in a specially designed locking roof rack 58 , of a type well known to those skilled in the art. The locking tie down strap 54 is comprised of two separate straps 60 and 61 . The first strap 60 is secured to pin 20 in lock 12 , in the same manner as described above with regard to the first end of the strap 14 . The outer end of the strap 60 , away from the buckle 12 , includes a plurality of openings 62 formed therein, similar to the holes formed in a belt worn around the waist of an individual. One of these openings 62 is inserted and held in a holder, such as a locking end 63 of a first slidable element 64 mounted on the rack 58 . The second strap 61 , includes an exterior end, having at least one opening 66 therein. This opening 66 is placed over a further holder or locking end 63 of a second movable or slidable end 64 of the roof rack 58 . An inner or loose end 68 of the second strap 61 is inserted around pin 24 in buckle 12 , pulled to a tight position, where it is held by end 26 , and the tie down strap 54 then locked in place by locking the locking member 34 in buckle 12 , as discussed above. It is to be understood that at least two lockable tie down straps 54 will be used to lock a surfboard, or the like, in place.
Referring now to FIGS. 7 and 8, there shown is a pair of lockable tie down straps 10 of the present invention used to secured a flexible load 70 , such as a duffel or sports bags, to an open carrying rack or pallet 72 . The rack or pallet 72 includes an open wire cage 74 and a pair of supporting members 76 , such as vehicle roof racks or pallet supports. As best shown in FIG. 8, the reinforced straps 14 are wrapped around the load 70 , through the wire cage 74 , with one of the straps passing around both supporting members 76 , and the other strap wrapped around the bottom of the wire cage. Both straps are then wrapped around the load 70 , with the loose ends 18 inserted around pins 24 , and cinched or tightened to the desired position, so as to hold the load 70 firmly in place. Each buckle 12 is then locked, as described above, so as to keep the reinforced straps 14 tightly cinched around the load 70 , and, therefore, maintain the load 70 locked to the rack/pallet 72 .
The lockable tie down straps 10 , 39 , 54 of the present invention solve the long-standing problem of securing various items or loads on vehicles, or the like, in a simple and secure manner, by utilizing one or more lockable tie down straps, which tie down straps are easily attached to and/or removed from around substantially any size or shape load. These lockable tie down straps are versatile, and save time and expense in safely securing equipment, or other loads, to vehicle racks, pallets, shelves, or the like.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. 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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A lockable tie down strap used to secure various loads to a variety of support surfaces, such as a vehicle, a boat, a pallet, a shelf, a tray, a cage, or the like. The lockable tie down strap has one loose end that is secured in a key-operated locking member to prevent theft, and is preferably constructed of a tubular webbing with steel cables running through the body of the webbing to prevent cutting of the strap, and thereby more securely hold a load by the strap. The strap may also be provided with loose ends having openings or a hook at the ends, for use with a roof rack or a wire cage to hold equipment or a flexible load in position.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a process for controlling combustion of burners attached to a furnace such as a firing kiln and an apparatus therefor.
(2) Related Art Statement
In order to control combustion of burners, it was conventionally a common process to proportionally control the output of each burner depending upon a temperature inside a furnace in the state that burning is continuously being effected through all burners. However, if burning is effected through the burners in the state that combustion output is throttled, an amount of a combustion gas is lacking, and the temperature distribution in the furnace largely varies. Consequently, a large amount of air needs to be forcedly fed into the furnace even in the state that the combustion output is throttled. An increased amount of fuel for the burners needs is required to heat the fed air.
In order to solve the above problem, a burner combustion-controlling process has been developed, which can control the temperature inside the furnace without throttling the combustion output through each of the burners. According to this process, the interior of the furnace is divided into a plurality of control zones, burners are arranged in the respective control zones, and successively subjected to combustion for a short time, while the control zones are successively employed as a combustion zone, and such a combustion cycle is repeated. FIG. 6 shows this process in the form of a time chart. For example, the interior of the furnace is divided into three control zones at upper, middle and lower stages. The upper stage burner is subjected to combustion for the first 6 seconds, then the middle stage burner is subjected to combustion for the next 6 seconds, and the lower stage burner is thereafter subjected to combustion for the succeeding 6 seconds, as represented in plots (A), (B) and (C), respectively. This cycle is repeated. Since each burner is subjected to combustion, although intermittently, without throttling its combustion output, this process has an advantage in that a large amount of air need not be fed inside the furnace. Further, the amount of generated heat through all the burners can be controlled by adjusting a time period from a point of time at which combustion through a certain stage burner is stopped to a point of time at which combustion is successively started through another stage burner.
On the other hand, it was clarified that when the above burner combustion-controlling process was applied to an actual furnace, the following problem occurred. That is, according to this burner combustion-controlling process, the burners in all the control zones are subjected to combustion in the same pattern depending upon the temperature inside the furnace. Thus, as shown in FIG. 7, it may happen that when the middle stage temperature approaches a preset temperature, the temperature in the upper stage section exceeds its preset temperature. As is understood from this, it was clarified that the above conventional intermittent burner combustion-controlling process cannot exhibit sufficient effect in reducing variations in the temperature distribution inside the furnace.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above-mentioned problem, and the invention has been accomplished to provide a burner combustion-controlling process which makes it possible to reduce variations in the temperature distribution in the furnace, without deteriorating the advantages attained by the conventional intermittent burner combustion-controlling process.
It is another object of the present invention to provide an apparatus for effecting such a burner combustion-controlling process.
A first aspect of the burner combustion-controlling process of the present invention, which has been made to solve the above problem, is characterized in that the interior of the furnace is divided into a plurality of control zones, at least one burner is arranged in each control zone and successively subjected to combustion for a short time, and this cycle is repeated, wherein at least one temperature sensor is fitted in each control zone, a time period during which combustion is effected through each burner is adjusted depending upon a difference between a temperature detected by the temperature sensor and a preset temperature in a respective control zone.
A second aspect of the burner combustion-controlling process of the present invention is characterized in that the interior of the furnace is divided into a plurality of control zones, at least one burner is arranged in each control zone and successively subjected to combustion for a short time, and this cycle is repeated, wherein at least one temperature sensor is fitted in each control zone, a time period during which combustion is effected through each burner is adjusted depending upon a difference between a temperature detected by the temperature sensor and a preset temperature, and if a detected temperature of a certain zone exceeds a preset temperature, combustion is skipped for the burner in said certain zone for a given time period during which said burner is to be subjected to combustion.
The burner combustion-controlling apparatus according to the present invention is adapted to control combustion through burners attached to a plurality of respective control zones that are defined by dividing an interior of a furnace, through repeating a cycle of successively subjecting the burners to combustion for a short time. The burner combustion-controlling apparatus includes means for feeding air to each of the burners, means for feeding a fuel gas to each of the burners, adjusting means for adjusting the air feeding means and the fuel feeding means, means for detecting a temperature in each of the control means, comparison means for memorizing a preset temperature in each of the control zone, comparing the preset temperature with the detected temperature in each of the control zones, and outputting a signal based on a comparison result, and intermittent combustion-controlling means for receiving said signal from the comparison means and outputting a signal to a burner-controlling means, said burner-controlling means adapted for receiving said signal from said intermittent combustion-controlling means and outputting a signal to the adjusting means to control feeding air and the fuel gas to each of the burners, the intermittent combustion-controlling means being adapted to output signals to said burner controllers to effect subjecting the burners to combustion in a preset circulating manner at a given interval and to adjust a time period during which combustion is effected through each burner, depending upon a difference between the temperature of said detecting means and the preset temperature. According to this apparatus, if there is a control zone in which the detected temperature exceeds the preset temperature, the burner in this control zone may be skipped through combustion for a given time period during which the burner is to be subjected to combustion.
According to the first aspect of the present invention, the temperature sensors are attached to a plurality of the respective control zones to detect the temperatures therein, and the time period during which each burner is subjected to combustion is adjusted depending upon the difference between the temperature detected by the temperature sensor and the preset temperature. Consequently, variations in the temperature distribution inside the furnace can be reduced. In addition, the advantage possessed by the above conventional process that the burners provided in the respective plural control zones are successively subjected to combustion for a short time without throttling the combustion output is not deteriorated.
According to the second aspect of the present invention, the temperature sensors are attached to a plurality of the respective control zones to detect the temperatures therein, and if the detected temperature in a certain control zone exceeds the preset temperature, combustion to be effected for a given time period is skipped for the burner in this certain control zone. Thus, as in the case of the first aspect of the present invention, the variations in the temperature distribution inside the furnace can be reduced.
These and other objects, features and advantages of the invention will be appreciated upon reading the following description of the invention when taken in conjunction with the attached drawings, with the understanding that some modifications, variations and changes of the same could be easily made by the skilled person in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference is made to the attached drawings wherein:
FIG. 1 is a sectional view of a furnace;
FIG. 2 is a block diagram of a burner combustion-controlling apparatus;
FIG. 3 is a time chart for illustrating a burner combustion-controlling process according to a first aspect of the present invention;
FIG. 4 is a time chart for illustrating a burner combustion-controlling process according to a second aspect of the present invention;
FIG. 5 is a perspective view of another embodiment of the present invention;
FIG. 6 is a time chart for illustrating the conventional burner combustion-controlling process; and
FIG. 7 is a graph illustrating the temperature inside the furnace when the conventional burner combustion-controlling process is employed.
DETAILED DESCRIPTION OF THE INVENTION
In the following, the present invention will be explained in more detail with reference to embodiments shown in the drawings.
In FIG. 1, a reference numeral 1 is a furnace, and three burners 2, 3 and 4 are attached to the furnace in the state that the burners 2 and 4 are opposed to the burner 3. In this embodiment, the interior of the furnace body is divided into three upper, middle and lower stage control zones, and one burner is arranged in each control zone.
FIG. 2 shows a burner combustion-controlling apparatus. Only a related portion of the burner 2 in the the upper stage control zone is shown. In FIG. 2, T 2 is a temperature sensor, and reference numerals 5, 6 and 7 show an adjuster, an intermittent combustion controller, and a burner controller, respectively. The temperature sensor T 2 detects the temperature in the upper stage control zone, and outputs a detected temperature signal to the adjuster 5. The adjuster preliminarily stores preset temperatures for the respective control zones, compares the detected temperature with a preset temperature based on the signal from the temperature sensor T 2 , and outputs a comparison result to the intermittent combustion controller 6. The intermittent combustion controller 6 preliminarily stores combustion cycling data including the combustion order, the combustion interval, the combustion duration, etc. for the burners, and receives the comparison results from the adjuster 5 and shortens the combustion duration for the burner in the control zone to be adjusted in temperature. The burner controller 7 outputs a control signal to a control valve 8.
The control valve 8 is intermittently opened or closed upon receipt of a control signal outputted from the burner controller 7, so that air is fed to the upper stage burner 2 through the control valve 8. Interlockingly with this, a fuel gas is fed through a pressure-equalizing valve 9 to the burner 2 where combustion is effected. Signals are sent to the burner 3 in the control zone at the intermediate stage from the intermittent burner controller 6 as well as to the burner 4 in the control zone at the lower stage, so that similar control is effected.
A reference numeral 10 is a pressure-equalizing valve which is always opened during operating the apparatus according to the present invention. This valve functions as an ordinary pressure-equalizing valve which regulates the flow rate of a fuel gas based on the pressure of air. Reference numerals 11 and 12 are a hand cock and a flow meter, respectively. Reference numerals 13 and 14 are a solenoid valve for safety purpose and a pressure-equalizing valve, respectively.
In the conventional burner combustion-controlling method mentioned before, the burner in each control zone is subjected to combustion according to the same pattern as shown in FIG. 6. On the other hand, according to the first aspect of the present invention, the temperature sensor is fitted in each control zone, the time period during which the burner is subjected to combustion is adjusted based on a difference between the temperature detected by the temperature sensor and a preset temperature. FIG. 3 illustrates a concrete example of such controlling. For example, if the temperature of the control zone at the upper stage exceeds the upper limit of a preset temperature range, the time period during which the burner 2 at the upper stage is subjected to combustion is gradually shortened, whereas if the detected temperature becomes lower than the lower limit of the preset temperature range, the shortened time period is restored to the original preset temperature, as represented by plot (A). Further, a similar controlling is illustrated with respect to the burner 3 at the intermediate stage, as represented by plot (B). Contrary to the conventional controlling process, according to the present invention, only the combustion time period is varied for each of the necessary combustions, but the overall intermittent combustion cycle is maintained as a whole.
According to the second aspect of the present invention, the temperature sensor is fitted in each control zone. With respect to the control zone in which the temperature detected by this temperature sensor exceeds the preset temperature, the burner in that control zone is skipped over through combustion preset for a given time period. FIG. 4 shows a concrete example of such controlling. For example, if the temperature in the control zone at the upper stage of the furnace exceeds the preset temperature and when time comes to subject the burner 2 at the upper stage to combustion, the burner is skipped over through combustion at this time, as represented in plot (A). If the detected temperature becomes lower than the preset temperature, combustion of the burner 2 begins to be effected. FIG. 4 shows similar controlling with respect to the burner 3 at the intermediate stage, as shown in plot (B). According to this control process, the burner or burners are skipped through combustion at given time period(s), but the overall intermittent combustion cycle is maintained as a whole.
When the combustion is controlled with respect to the burners as mentioned above, the advantage obtained when the burners in plural control zones are successively subjected to combustion for given short time period without throttling the burners is maintained as it is, and the disadvantage occurring when the combustion outputs of the burners are throttled is avoided. In addition, since the combustion of the burners can be controlled with respect to each of the control zones, variation in the temperature distribution inside the furnace can be reduced.
In the above embodiments, a single burner is arranged in each of the control zones. However, as shown in FIG. 5, the furnace body 1 is divided into three, i.e., upper, intermediate and lower control zones, and a plurality of burners 2, 3, 4 may be arranged in each control zone. In this case, those burners belonging to the same control zone are controlled together. Although a plurality of the control zones are arranged vertically in the above embodiments, such control zones may be defined in a lateral direction of the furnace body. A single temperature sensor may be arranged for every control zone or for every burner.
For example, a single furnace in which eight burners were arranged in each of the control zones at the upper, intermediate and lower stages, respectively, was used, the temperature in the furnace was set at 350° C., and a difference in the temperature distribution between an upper portion and a lower portion was measured. As a result, it was made clearer that the temperature difference was 121° C. in the case of the conventional combustion-controlling process as shown in FIG. 6, whereas the temperature difference was reduced to 83° C. in the case of the combustion-controlling process according to the first aspect of the present invention.
As mentioned above, according to the burner combustion-controlling process and apparatus of the present invention, the variation in the temperature distribution inside the furnace can be diminished without damaging the advantage in the conventional intermittent burner combustion-controlling process. Accordingly, the invention process is favorably adopted to control the combustion of the burners in the furnace for firing the ceramic articles which are likely to be damaged by temperature differences.
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A process for controlling combustion of burners arranged in a plurality of respective control zones divided in a furnace, includes the step of repeating a cycle of successively subjecting the burners to combustion for a short time. At least one temperature sensor is fitted in each control zone, a time period during which each burner is subjected to combustion is controlled according to a difference between a temperature detected by the corresponding temperature sensor and a preset temperature in a respective control zone. An apparatus is also disclosed for effecting such a controlling process.
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FIELD OF THE INVENTION
This invention relates to the processing of photographic materials and to a processing system therefor.
BACKGROUND OF THE INVENTION
In the processing of photographic materials such as paper and film it has sometimes been found that a stain appears in the developed material. The staining is due primarily to retained sensitising dye. The risk of a staining is greater in the case of rapid processes which have been developed employing short cycle times and in which the durations of the individual stages of development, bleach-fix and wash are correspondingly short.
PROBLEM TO BE SOLVED BY THE INVENTION
Certain chemical compounds, known in the art as stain reducing agents, have been previously used for reducing staining and it has been proposed to add a stain reducing agent to the developer liquid. However it has been found that when a short wash time is employed, for example about 15 seconds, that a stain is produced on the developed material. The inventor of the present invention has found that when the concentration of stain reducing agent in the developer solution is increased, the stain is initially reduced but after about 4 weeks is found to increase substantially. Furthermore, they have found that stain reducing agents are not very soluble in the developer solution and tend to precipitate. The stain reducing agent can be added to the bleach-fix solution with the effect that the stain is reduced but here the stain reducing agent is even more prone to precipitate than in the developer. If the stain reducing agent is added to wash water or stabiliser-replenisher it is soluble to a high degree and prevents stain initially but is present in the entire wash and thus retained in the photographic material.
A solution to this problem has now been invented in which the stain reducing agent is added to the first wash or stabiliser tank only and not to subsequent wash or stabiliser tanks. Stain reducing agent is more soluble in this solution than in the developer or bleach-fix and hence the amount in solution is enough to prevent staining. In a preferred embodiment of the invention the wash or stabiliser tanks are run at elevated temperature sufficient to remove the stain reducing agent from the photographic material.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process for the processing of an imagewise exposed photographic material which has been subjected to development and bleach-fixing which process comprises a plurality of sequential washing steps and where a stain reducing agent is employed wherein the photographic material is contacted with an effective amount of the stain reducing agent in the wash liquid in a first washing step and the photographic material is subjected to a following washing step to remove the stain reducing agent.
ADVANTAGEOUS EFFECT OF THE INVENTION
The advantage of the invention is that staining is kept to a low level.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the effect on stain level of an increase in the wash temperature.
FIG. 2 shows a typical arrangement of developer, bleach-fix and wash tanks in a minilab photoprocessor system.
DETAILED DESCRIPTION OF THE INVENTION
References to a wash liquid being free of stain reducing agent mean that no stain reducing agent is present apart from that which may be carried over by the photographic material from the previous tank.
The term wash liquid is intended to include stabilising liquid. The invention is particularly applicable to rapid processing using short cycle times and correspondingly short individual steps.
The invention is suitable for use in small photoprocessors which have become known as minilabs. These usually have a total of four wash or stabiliser tanks. When such a processor is employed the stain reducing agent will normally be added to the wash liquid in the first tank only and the wash liquid in subsequent tanks will be free of stain reducing agent apart from contamination by carry over. The stain reducing agent will select from those that remove sensitising dye and are removable by water washing so that neither are retained in the developed photographic material. Suitable agents include those containing a diamino stilbene structure. Suitable stain reducing agents are disclosed in U.S. Pat. No 5,395,742
Suitable concentrations of stain reducing agent in the wash liquid are up to about 12 g/l preferably from about 1 to about 9 g/l.
Suitable stain reducing agents are those sold under the trade names Phorwite REU, Tinopal SFP and Uvitex MST 300. Phorwite is preferred.
Phorwite has the chemical formula:
According to another aspect of the invention a photoprocessor system for the processing of photographic materials, for example film or paper comprises: a development tank ( 2 ) associated with a bleach-fix tank ( 4 ) which is associated with a first of a plurality of wash tanks ( 6 , 8 , 10 and 12 ) connected in series and wherein there is provided a reservoir ( 14 ) for a stain reducing agent and means ( 16 ) for supplying the stain reducing agent to the first wash tank ( 6 ).
The photoprocessor may be a small photoprocessor known in the art as a minilab. In this case it is preferred that the stain reducing agent is present in the wash liquid in the first wash tank whilst the wash liquid in the subsequent wash tanks (usually three in number as there are usually four wash tanks in total) contains no stain reducing agent apart from any carry over.
Referring to FIG. 2 minilab is indicated generally by reference numeral 1 . Photographic paper which moves in a direction of from left to right as indicated by the arrow is passed through the developer liquid in tank 2 . Tank 2 is replenished as indicated by the arrow and letter R. The paper is then passed through the bleach-fix liquid in tank 4 . Tank 4 is also replenished as indicated by the arrow and letter R.
The liquid levels in tanks 2 and 4 are maintained constant by overflow (not shown).
The paper is then passed through the wash liquid in the wash tank 6 which is the first of four wash tanks 6 , 8 , 10 and 12 .
The stain reducing agent is added to the wash liquid in tank 6 and will be replenished to maintain the concentration at the desired level in the range 2 to 12 g/l. The liquid level in tank 6 is maintained constant by replenishment indicated by the letter R and by overflow (not shown). The wash liquid in tank 12 is replenished as indicated by the letter R with water or stabiliser free of stain reducing agent and the level maintained constant by overflow into tank 10 which in turn overflows into tank 8 which overflows into tank 6 . Thus the direction of the photographic paper is countercurrent to the flow of liquid in the wash tanks. Stain reducing agent on the paper as a result of passage through tank 6 is removed in the subsequent washing tanks 8 , 10 and 12 .
The invention is illustrated by the following Examples.
EXAMPLE 1
In this Example a short process cycle as shown in Table 1 was run in a sinkline in which the first wash tank contained either water as a comparison or Phorwite REU.
TABLE 1
short process cycle
Temperature
Develop
15 seconds
40° C.
bleach-fix
15 seconds
40° C.
first wash
5 to 20 seconds
37° C.
main wash
15 seconds
37° C.
Where the developer is Kodak (Registered Trade Mark) Ektacolor SM (Registered Trade Mark) developer, bleach-fix is Kodak Ektacolor SM bleach-fix (pH 6.3). The paper used was Ektacolor Edge 7. The first wash stage included a water check and solutions of Phorwite REU at 2 g/l and 8 g/l. Phorwite REU is an optical brightener. The reference process cycle is shown in Table 2.
TABLE 2
long process cycle
temperature
develop
45 seconds
37.8° C.
bleach-fix
45 seconds
37.8° C.
wash
90 seconds
35° C.
Where the developer is Kodak (Registered Trade Mark) RA-12 developer and the bleach-fix is Kodak RA-12 bleach-fix. This process gives the reference values for CIELAB stain measurements for Kodak Ektacolor (Registered Trade Mark) Edge 7 paper and these are shown in Table 3. These are the values to be aimed at for the short process cycle.
The results are in Table 3 in terms of CIELAB stain measurements L, a* and b* which were measured in all cases reported herein on a special array densitometer with a UV filter in the light source.
TABLE 3
Stain measurements
first wash
solution
total wash
strip
see Table
first wash
time 90
L
a*
b*
ref
2
reference
time
seconds
90.647
−0.007
−1.158
147-1
Water
comparison
5 seconds
20
89.703
0.288
0.636
147-14
REU (2 g/l)
invention
5
20
89.73
0.508
−0.697
147-13
REU (8 g/l)
invention
5
20
89.908
0.331
−0.569
147-7
Water
comparison
10
25
89.861
0.307
0.505
147-15
REU (2 g/l)
invention
10
25
89.95
0.270
−0.512
147-8
REU (8 g/l)
invention
10
25
90.12
0.188
−1.008
147-9
Water
comparison
20
35
90.135
0.044
−0.547
147-16
REU (2 g/l)
invention
20
35
90.087
0.194
−1.015
147-10
REU (8 g/l)
invention
20
35
90.395
0.034
−1.430
It can be seen from the data in Table 3 that the presence of Phorwite REU in the first wash tank shows that L and a* are not affected very much but they do show a small improvement towards the aim reference values. The improvement in b* is much more significant. For the higher level of Phorwite b* is better than the reference value for a much shorter wash time of 35 seconds compared with 90 seconds.
Observation of the paper strips when placed under an ultraviolet lamp (366 nm) showed a small amount of fluorescence for strips with Phorwite REU in the first wash tank that had a following 15 second wash. Strips in which the final 15 second wash was omitted showed a strong fluorescence. This indicates that some but not all the Phorwite REU is removed in the final 15 second wash.
In order to remove any retained Phorwite another experiment was run with a longer final wash of 60 seconds. The data are shown in Table 4.
TABLE 4
Long final wash
first wash
solution
total wash
strip
see Table
first wash
time 90
L
a*
b*
ref
2
reference
time
seconds
90.647
−0.007
−1.158
147-3
water
comparison
5 seconds
65
90.44
−0.222
−0.916
147-4
REU (8 g/l)
invention
5
65
90.635
−0.192
−1.04
147-5
water
comparison
10
70
90.504
−0.2
−0.81
147-6
REU (8 g/l)
invention
10
70
90.605
−0.122
−1.25
147-11
water
comparison
20
80
90.511
−0.202
−1.158
147-12
REU (8 g/l)
invention
20
80
90.701
−0.078
−1.829
It can be seen from Table 4 that even with a long final wash the presence of Phorwite REU in the first wash tank improves the stain position relative to the same tank without Phorwite. In addition the final stain is better than the reference for a total wash time of 70 seconds or more and even at 65 seconds it is very close to the reference values.
Examination of the strips under an ultraviolet lamp at 366 nm showed that there was only very slight fluorescence indicating almost no retained Phorwite in the paper.
Thus it is possible to shorten wash time and obtain a stain position as good as or better than the reference by using the principle of including Phorwite REU in the first wash tank but not in the following wash tanks. It is also possible by this method to prevent retained Phorwite REU in the coating with shorter wash times than the reference process.
This example demonstrates the first benefit of the invention in that shorter wash times are possible, with no retained Phorwite and fresh stain levels equal or better than the reference.
EXAMPLE 2
This experiment demonstrates the benefit of higher temperature washing.
In this example a relatively poor wash condition was deliberately used to check the effect of wash water temperature on the stain level in colour paper. The process cycle used was as in Table 5.
TABLE 5
short process cycle
temperature
develop
15 seconds
40° C.
bleach-fix (pH 5.4)
15 seconds
40° C.
wash
30 seconds
21 to 55° C.
Where the developer is Kodak Ektacolor SM developer, bleach-fix is Kodak Ektacolor SM bleach-fix (pH 5.2). This condition with the lower pH in the bleach-fix than used in Example 1 coupled with a 30 second wash results in a worse stain position than the reference values. The paper used was Ektacolor Edge 7.
It can be seen from FIG. 1 that on average b* falls by over one unit with increase in temperature from 22 to 55° C. This is a significant improvement in the stain level in the next example temperature increase in the wash is used in combination with Phorwite REU in the first wash tank to lower retained Phorwite in the paper.
EXAMPLE 3
According to the invention.
In this example Phorwite REU was present in the first wash tank and the main wash was examined at two different temperatures as shown in the process cycle in Table 6.
TABLE 6
short process cycle
temperature
develop
15 seconds
40° C.
bleach-fix
15 seconds
40° C.
first wash
5 to 20 seconds
40° C.
main wash
15 seconds
37 and 56° C.
The results are shown in Table 7.
TABLE 7
Effect of Phorwite and final wash temperature
First wash
wash
total
strip
solution
temperature
first wash
wash time
L
a*
b*
ref
see Table 2
35
time
90 seconds
90.647
−0.007
−1.158
147-14
REU (2 g/l)
37
5 seconds
20
89.729
0.509
−0.697
147-18
REU (2 g/l)
56
5
20
90.2493
0.149
−0.964
147-15
REU (2 g/l)
37
10
25
89.95
0.270
−0.512
147-19
REU (2 g/l)
56
10
25
90.314
0.086
−0.712
147-17
REU (2 g/l)
37
15
30
90.265
0.097
−0.785
147-21
REU (2 g/l)
56
15
30
90.349
0.084
−1.086
147-16
REU (2 g/l)
37
20
35
90.087
0.194
−1.015
147-20
REU (2 g/l)
56
20
35
90.309
0.076
−1.162
The data in Table 7 shows that the values of L, a* and b* are closer to the reference values for the final wash with the higher temperature. In addition by viewing the strips under an ultraviolet lamp at 366 nm it was clear that there was some fluorescence for the low temperature wash particularly at short wash times but there was almost no fluorescence for any of the wash times for the higher temperature wash. These data indicate that a higher wash temperature lowers stain and in addition prevents retention of Phorwite REU in the paper.
The values of L, a* and b* are very close to the reference values and thus the method described in the invention in which Phorwite REU is present only in the first wash tank followed by a main wash which does not contain Phorwite REU but is run at a higher temperature can give low stain levels even for very short wash times.
This example demonstrates the second benefit of the invention whereby even shorter wash times than those already demonstrated in example 1 are possible with stain levels as good as the reference.
EXAMPLE 4
According to the invention.
It has been found that if paper strips processed with short wash times are left stacked together for a period of time a room temperature, largely without any incident light, the stain level can increase. This is particularly noticeable in the b* value and corresponds to an increase in yellow stain. Some strips (processed by the methods described in this report) were re-measured after standing for 4 weeks at room temperature. (22° C.). Some results are shown in Table 8.
TABLE 8
Strips re-measured after 4 weeks
first wash
first wash
total wash
Strip
solution
time
time
L
a*
b*
147-1
water
comparison
5 seconds
20 seconds
89.703
0.288
0.636
147-1b
water
re-
5 seconds
20
89.396
−0.017
3.468
measured
147-14
REU (2 g/l)
invention
5
20
89.73
0.508
−0.697
147-14b
REU (2 g/l)
re-
5
20
89.565
0.188
1.339
measured
147-13
REU (8 g/l)
invention
5
20
89.908
0.331
−0.569
147-13b
REU (8 g/l)
re-
5
20
89.786
0.042
1.453
measured
147-7
water
comparison
10
25
89.861
0.307
0.505
147-7b
water
re-
89.691
0.247
1.828
measured
147-15
REU (2 g/l)
invention
10
25
89.95
0.270
−0.512
147-15b
REU (2 g/l)
re-
10
25
89.844
0.202
0.388
measured
147-8
REU (8 g/l)
invention
10
25
90.12
0.188
−1.008
147-8b
REU (8 g/l)
re-
10
25
90.05
0.101
−0.048
measured
147-9
water
comparison
20
35
90.135
0.044
−0.547
147-9b
water
re-
20
35
90.04
−0.091
0.524
measured
147-16
REU (2 g/l)
invention
20
35
90.087
0.194
−1.015
147-16b
REU (2 g/l)
re-
20
35
90.212
0.124
−0.404
measured
147-10
REU (8 g/l)
invention
20
35
90.395
0.034
−1.430
147-10b
REU (8 g/l)
re-
20
35
90.385
0.049
−0.909
measured
The data in Table 8 show that after keeping for 4 weeks stain levels have increased for all strips. In all cases the stain for the water comparison increases more than the Phorwite example.
This shows the third benefit of the invention in that stain increases on keeping after short wash times are less if Phorwite REU is present in the first wash tank. It is desired however to employ the method of the invention and to further lower the stain increase on keeping and this is shown in the next example.
EXAMPLE 5
According to the invention.
If the final wash is extended as in the example described in table 3, the general stain increase on keeping can be lowered irrespective of the method. The data are shown in Table 9.
TABLE 9
Strips re-measured after 4 weeks (long final wash)
first wash
first wash
total wash
Strip
solution
time
time
L
a*
b*
147-3
water
comparison
5 seconds
65
90.44
−0.222
−0.916
147-3b
water
re-
5
65
90.44
−0.196
−0.529
measured
147-4
REU (8 g/l)
invention
5
65
90.635
−0.192
−1.04
147-4b
REU (8 g/l)
re-
5
65
90.641
−0.150
−0.762
measured
147-5
water
comparison
10
70
90.504
−0.2
−0.81
147-5b
water
re-
10
70
90.479
−0.160
−0.444
measured
147-6
REU (8 g/l)
invention
10
70
90.605
−0.122
−1.25
147-6b
REU (8 g/l)
re-
10
70
90.626
−0.010
−1.101
measured
147-11
water
comparison
20
80
90.511
−0.202
−1.158
147-11b
water
re-
20
80
90.529
−0.129
−0.997
measured
147-12
REU (8 g/l)
invention
20
80
90.701
−0.078
−1.829
147-12b
REU (8 g/l)
re-
20
80
90.759
−0.063
−1.735
measured
The data in Table 9 show unexpectedly thst even with longer wash times compared with those shown in example 1 the benefit of Phorwite in the first was tank is still demonstrated. The stain increases on keeping is less for the Phorwite examples and is minimal at the longer times. Thus although these wash times are longer than desired they are still shorter than those used in the reference process.
This shows the fourth benefit of the invention in that shorter wash times than the reference can be achieved, with no retained Phorwite REU and with minimal stain increase on keeping.
It is however desired to shorten the wash times even more than in the above example. This is shown in the next example.
EXAMPLE 6
According to the invention.
In this example the use of Phorwite in the first wash tank is combined with a following wash at higher temperature (56° C.). The results are shown in Table 10. The strip numbers with the b suffix are the re-measured strips.
The b suffix means the strips were re-measured after 4 weeks.
TABLE 10
Effect of Phorwite and final wash temperature re-measured strips
first wash
wash
first wash
total wash
strip
solution
temperature
time
time
L
a*
b*
147-14
REU (2 g/l)
37
5 seconds
20
89.729
0.509
−0.697
147-14b
″
37
5
20
89.568
0.188
1.339
147-18
REU (2 g/l)
56
5
20
90.2493
0.149
−0.964
147-18b
″
56
5
20
90.215
0.095
−0.446
147-15
REU (2 g/l)
37
10
25
89.95
0.270
−0.512
137-15b
″
37
10
25
89.844
0.202
0.389
147-19
REU (2 g/l)
56
10
25
90.314
0.086
−0.712
147-19b
″
56
10
25
90.326
0.086
−0.331
147-17
REU (2 g/l)
37
15
30
90.265
0.097
−0.785
147-17b
″
37
15
30
90.053
0.179
−0.470
147-21
REU (2 g/l)
56
15
30
90.349
0.084
−1.086
147 21b
″
56
15
30
90.38
0.206
−0.956
147-16
REU (2 g/l)
37
20
35
90.087
0.194
−1.015
147-16b
″
37
20
35
90.212
0.124
−0.404
147-20
REU (2 g/l)
56
20
35
90.309
0.076
−1.162
147-20b
″
56
20
35
90.343
0.097
−0.996
It can be seen from Table 10 that the higher temperature final wash has better fresh stain values and also lower stain increase after keeping. The stain values for 30 seconds or more total wash are now very close to the reference values and show almost no increase on keeping. An examination of the strips under an ultraviolet lamp at 366 nm shows almost no fluorescence for the higher temperature cases even at short wash times. This shows that Phorwite REU is not retained in the paper.
This demonstrates the fifth benefit of the invention in that very short wash times are possible with low fresh stain, no retained Phorwite REU and minimal increase in stain on keeping.
EXAMPLE 1a
Two other stain reducing agents were compared with Phorwite REU. These were Tinopal SFP and Uvitex MST 300.
These stain reducing agents were dissolved in the first wash at 0, 2 and 8 g/l in tap water.
The paper was Ektacolor Edge 7. This paper was about 6 months older than when used for the original experiments with Phorwite REU so the basic stain level was expected to be higher.
TABLE 1a
process cycle
Temperature
develop
14 sec
40° C.
blix
14 sec
40° C.
first wash
5, 10, 15 sec
40° C.
final wash
15 sec
36° C.
dry
in air
Where the developer is Ektacolor SM tank developer, and the blix is Ektacolor SM tank bleach-fix The blix was adjusted to pH of 6.2 before use.
The results are shown in Table 2a are for 2 g/l stain reducing agent and in 3a for 8 g/l stain reducer. In these experiments the first wash was 5, 10 or 15 seconds.
The final wash was always 15 seconds. Water was used as the check for the first wash in each case.
The data shown in Table. 2a show the CIELAB measurements (L, a* and b*)and the red, green and blue (RGB) Dmin density measurements with and without a UV filter in the light source. A consistent pattern is clear in that Phorwite lowers b* and B Dmin more than other materials although all the stain reducers show an improvement over the water check.
The data in Table 3a are similar to those in Table 2a except that the effects are greater for the higher level of stain reducer. Phorwite REU consistently has lower b* and B Dmin values with and without a UV filter than the other stain reducers although all of them show an improvement over the water check.
TABLE 2a
Comparison of stain reducers in first wash (2 g/l)
u.v filter
no u.v filter
D min × 1000
Dmin × 1000
first wash
time
L
a*
b*
R
G
B
R
G
B
water
5
90.67
−1.25
0.46
110
102
111
95
93
91
Tinopat
5
90.62
−1.27
0.78
109
104
113
94
94
88
(2 g/l)
Uvitex
5
90.60
−1.33
0.64
111
104
114
93
94
91
(2 g/l)
Phorwite
5
90.43
−1.13
0.02
112
105
110
97
96
88
(2 g/l)
water
10
90.63
−1.25
0.42
110
104
111
92
93
90
Tinopat
10
90.78
−1.16
0.54
107
102
108
90
91
81
(2 g/l)
Uvitex
10
90.62
−1.28
0.11
110
103
108
93
93
83
(2 g/l)
Phorwite
10
90.62
−1.10
−0.4
110
104
103
95
94
80
(2 g/l)
water
15
90.72
−1.10
0.05
108
102
107
92
92
88
Tinopal
15
90.66
−1.09
0.04
108
103
104
94
04
76
(2 g/l)
Uvitex
15
90.77
−1.15
0.16
108
101
106
91
90
78
(2 g/l)
Phorwite
15
90.76
−1.01
−0.4
108
102
101
93
94
77
(2 g/l)
TABLE 3a
Comparison of stain reducers in first wash
u.v filter
no u.v filter
D min × 1000
Dmin × 1000
first wash
time
L
a*
b*
R
G
B
R
G
B
water
5
90.67
−1.25
0.46
110
102
111
95
93
91
Tinopal
5
90.54
−0.76
1.06
106
106
113
89
98
86
(8 g/l)
Uvitex
5
90.56
−1.27
0.68
111
104
113
94
94
86
(8 g/l)
Phorwite
5
90.65
−1.18
0.15
110
103
106
94
95
81
(8 g/l)
water
10
90.63
−1.25
0.42
110
104
111
92
93
90
Tinopal
10
90.6
−1.94
0.37
108
104
106
92
93
73
(8 g/l)
Uvitex
10
90.52
−1.22
0.03
111
104
108
94
95
78
(8 g/l)
Phorwite
10
90.71
−0.98
−0.3
108
103
102
93
94
74
(8 g/l)
water
15
90.72
−1.10
0.05
108
102
107
92
92
88
Tinopal
15
90.65
−0.99
0.00
108
103
104
93
94
70
(8 g/l)
Uvitex
15
90.66
−1.12
−0.03
109
103
106
92
93
73
(8 g/l)
Phorwite
15
90.69
−0.85
−0.77
109
103
97
92
93
67
(8 g/l)
EXAMPLE 2a
In this example the effect of the stain reducers on Dmax is examined and also the ease with which they wash out of the coating. The strips were processed in the standard Ektacolor SM process and dried. They were then measured for B Dmax (1), immersed in a solution of water or the stain reducing agent at 2 g/l for 15 seconds, dried measured for B Dmax (2) and then washed for 15 seconds, dried, measured for B Dmax(3).
TABLE 4a
Effect of stain reducers (2 g/l) on blue Dmax.
compound
B Dmax1
B Dmax2
B Dmax3
water
2.14
2.14
2.14
Tinopal (2 g/l)
2.14
1.99
2.03
Uvitex (2 g/l)
2.13
2.00
2.05
Phorwite (2 g/l)
2.14
2.06
2.11
It can be seen that after treatment with the stain reducers there is a loss of B Dmax which is caused by the fluorescence of retained stain reducer, thus it is desired to minimise the loss of B Dmax but also to maximise the improvement in B dmin also caused by the stain reducer. In the case of some stain reducers, particularly Phorwite REU, the improvement in B Dmin is only partly caused by (a) fluorescence but also mainly by (b) assisting the removal of retained sensitising dye. Thus an improvement in B Dmin should be obtainable by mechanism (b) by the method of the invention, this appears to be the case from the data shown above. In Table 4a the loss in B Dmax (2) is less for Phorwite than the others. In addition the restoration of B Dmax (3) after a I5 second wash is better with Phorwite than the others. In all Phorwite shows only a 0.03 loss of B Dmax whereas the others show 0.08 (Uvitex) and 0.11 (Tinopal). The data combined with that from Tables 2a and 3a in which Phorwite shows a significant improvement in B Dmin demonstrates the invention.
The same experiment was repeated with 8 g/l of stain reducer.
TABLE 5a
Effect of stain reducers (8 g/l) on blue Dmax
compound
B Dmax1
B Dmax2
B Dmax3
water
2.13
2.13
2.13
Tinopal (8 g/l)
2.14
1.84
1.96
Uvitex (8 g/l)
2.13
1.92
2.00
Phorwite (8 g/l)
2.14
1.94
2.06
Phorwite shows only a 0.08 loss of B Dmax whereas Uvitex shows 0.13 and Tinopal 0.18.
Thus the method of the invention is demonstrated in that a reduction in blue Dmin density is obtainable by the inclusion of a stain reducer in the first wash followed by a completion of the wash without stain reducer. In addition the loss in blue Dmax caused by the retention of the stain reducer is minimised. This combination of desired results can be highlighted by the ratio of the blue Dmax to the blue Dmin as shown in Table 6a.
TABLE 6a
ratio of B Dmax/B Dmin
compound
Dmax/Dmin (2 g/l)
Dmax/Dmin (8 g/l)
water
24.2
24.2
Tinopal
26.7
28.0
Uvitex
26.3
27.3
Phorwite
27.4
30.7
Here it can be seen that all the stain reducers are beneficial in the first wash compared with water which demonstrates the principal of the invention but also that Phorwite REU is better than the other two.
|
A process for the processing of an imagewise exposed photographic material which has been subjected to development and bleach-fixing comprises a plurality of sequential washing steps and where a stain reducing agent is employed wherein the photographic material is contacted with an effective amount of the stain reducing agent in the wash liquid in a first washing step and the photographic material is subjected to a following washing step to remove the stain reducing agent. The process may employ a plurality of wash tanks in which the developed material is washed sequentially and the stain reducing agent is present in the wash liquid in a first wash tank and removed from the photographic material by the wash liquid in one or more following wash tanks. The temperature of wash liquids in the tanks is preferably within the range 40 to 70° C., preferably 45 to 65° C.
The invention includes a photoprocessor system for the processing of photographic materials for example film or paper comprising: a development tank associated with a bleach-fix tank which is associated with a first of a plurality of wash tanks connected in series and wherein there is provided a reservoir for a stain reducing agent and means for supplying the stain reducing agent to the first wash tank.
| 6
|
BACKGROUND OF THE INVENTION
1. Field of Invention
The field of art to which this invention relates includes, generally, that of simulator control loading systems and, more particularly, to an improved high performance system for developing realistic reaction forces in manually-operable controls in a vehicle simulator.
This invention is adapted particularly to hydraulic control loading systems for use with a vehicle simulator such as shown in the U.S. Pat. No. 4,236,325, issued Dec. 2, 1980, to John D. Hall et al. and assigned to the same assignee as the present invention.
2. Description of the Prior Art
Today, one of the best and most widely accepted ways of teaching pilots to fly is through the use of an aircraft simulator which permits the accumulation of flight experience without the high risk and the excessive cost that otherwise may be involved. To be a truly effective teaching instrument, however, the flight simulator must provide sensory cues that are realistic to the pilot trainee.
One important contributor to the realism of a simulator is the "feel" associated with the primary flight controls. Since aircraft control surfaces do not exist in a simulator, the forces associated with the surfaces must be produced by artificial means in order to create the necessary "feel" at the control.
Therefore, a system to "load" the control is required if the aircraft's control forces are to be duplicated. Many training judgments depend upon a pilot's response to these forces and to the "feel" of the controls.
For example, during flight operation of an actual aircraft, the pilot must control his ailerons, elevator and rudder to maneuver an aircraft. This control is maintained by a pilot's use of both hands and feet by holding on to a conventional control stick to control the elevator and the aileron systems while stepping on foot pedals to operate the rudder system.
To simulate these controls effectively, forces must be developed in the control stick and in the foot pedals to replace these missing forces. A pilot must "feel" not only these forces but also the effects of his actions as communicated to him through these forces applied to these controls.
As a pilot moves his control stick and adjusts the position of his foot pedals to maneuver his aircraft, he must feel resistance in his hand and his feet, simulating the actual resistance that a pilot flying an actual aircraft would feel. Here the requirement is not only for high performance on the part of the simulator control loading system but also for the capability of verification that the system is within certain specified standards of operation.
In addition, the quest for higher performance in this simulator control loading system has been accompanied by a trend in the industry to move away from subjective acceptability standards to those which have taken over in other areas in simulation; namely, the use of measurement and calibration systems which will ensure a close matching of the simulator control system force and position curves to those which are obtained in actual performance of operational aircraft.
Several different types of control loading systems have been developed in the past and some of these are currently in use in simulators today. Many of these systems employ force feedback techniques in order to produce electrical signals that are representative of the required control forces.
Typically, in a force feedback system, a computer is used to generate an electrical signal corresponding to the control force that is required for any given flight condition. This signal reflects the aerodynamic characteristics of the aircraft being simulated and the particular flight maneuver being performed.
In addition, an electrical signal representing the force exerted on the control by the pilot is generated. The pilot's force signal is fed back and compared with the required force signal. A signal corresponding to the difference between the required force and the pilot's force is generated to obtain proper loading of the control.
U.S. Pat. No. 4,236,325 teaches the use of a servo valve and a hydraulic actuator in combination to provide loading of simulator controls. A signal representing the difference between actual and required forces is used to drive a servo valve which, in turn, provides hydraulic oil flow to an actuator. The magnitude and the polarity of the driving signal determines the amount of hydraulic oil flow to each side of the actuator's piston.
A difference in the amount of hydraulic oil on opposing sides of the actuator's piston will cause the piston to move and exert a force on the piston rod. Therefore, by connecting the controls to the piston rod by appropriate mechanical linkage, the necessary force is transmitted to the controls.
During normal operation of some control loading systems suggested in the past, various forces are produced in order to obtain the proper "feel" in the controls. While some of these forces may be large enough to pose a threat to the safety of a pilot, they must be produced in this magnitude in order to simulate accurately the control's characteristics under certain flight conditions.
On the other hand, force levels above those that can be encountered in an actual aircraft must not be permitted to be transmitted to the controls in the simulator. Therefore, most of the control loading systems in the past do not develop these forces in a magnitude sufficient for obtaining the proper "feel" in these manually-operable controls.
There can be failures in either the hydraulic or the electrical means which make up the control loops to provide the "feel" to simulated aircraft controls. Where the failure is in the hydraulic system and where the electrical controls are still operative, additional electrically controlled elements can usually activate safety devices to protect equipment and personnel.
However, circumstances may conspire to prevent the electrical controls from functioning correctly, or a hydraulic failure may occur too rapidly for effective control by electrical means. For these reasons, most of the control loading systems in the past do not develop performance to the high level that is obtainable consistently and reliably by the present invention.
Among the prior art devices for dealing with this problem by providing hydraulic safety means are U.S. Pat. No. 3,033,174 and U.S. Pat. No. 3,067,725 both of which are in the name of Harold S. Hemstreet and both assigned to the same assignee as the present invention.
In the past, it has been suggested to use electrical controls attached to a servo valve with a relay to actuate the valve. The connection is such that the relay operates the valve in response to changes in electric current flow corresponding to certain changes in pressure which are indicative of hydraulic failure.
Such devices have proven unsatisfactory, however, since they respond only to very large changes in hydraulic pressure and introduce an undesireable time delay. If some of these prior art devices are operated at the high performance level that is needed in the simulator field, the system could be exposed to at least one violent shock before the safety device becomes operative.
Another prior art device proposes simple mechanical stops which are intended to absorb the force that is generated in excess to a desired or safe force. These stops are inadequate for many installations where space requirements are such that the mechanical stops can not be placed in a way to stop the undesired motion adequately. An example of such limited space is to be found in the cockpit space of aircraft simulators.
A pilot trainee is quite sensitive to shock and vibration in the control forces so that it is highly desireable and generally necessary to provide a better high frequency response in a flight simulator control loading system. Since striking a limit stop, for example, may create an audible knock, there are situations wherein such audible sounds detract substanstially from the realism sought to be obtained.
In modern grounded aircraft training systems, it is acknowledged that failthfulness of simulation is required for adequate training, particularly for training persons to operate present day aircraft of increasingly higher performance. It is acknowledged also that pilot familiarity with particular aircraft is based to a considerable degree upon recognition of both the static and the dynamic control forces which the pilot must apply to the aircraft controls in order to perform various maneuvers.
Shortcomings in the control loading systems included with a flight simulator may have an adverse effect upon the simulator flying qualities, with a result of material decrease in the validity of training. A control loading system must provide a force-generating system of considerable force capability which must have a realistically smooth "feel" and have extremely small friction, except for the small amount of friction present in an actual aircraft system. The generation of large hydraulic forces also have attendant risk of control unit damage through overloading or overheating.
Very small amounts of aileron or elevator friction can cause serious difficulty in maintaining an aircraft trimmed in flight, particularly at high speeds. When a control loading system is used as a part of an autopilot or other closed-loop control system, it is mandatory that the system meet certain dynamic requirements connected with the over all stability of the complete autopilot system.
Today's high standards of simulation require that the control loading unit be capable of generating non-linear force verses displacement curves, break-away forces or detent effects (corresponding to similar effects deliberately introduced into aircraft control systems), and limiting of stick travel as the result of limiting aerodynamic hinge movements or reduced hydraulic system capabilities during emergency operation.
In flight simulator control loading systems, it is necessary to generate forces on the manually-operable controls that are proportional, other factors, to such variables as control displacement, control trim positon, aerodynamic parameters, autopilot forces, etc. In artificial force-producing systems, a large variety of factors determine the magnitude of force in existence at a particular instance on the control.
Utilizing the present invention, the various nonlinearities and the rigid dynamic requirements for an aircraft flight simulator can be met without difficulty through electronic circuitry, as will be described in more detail presently. Thus, there has existed a long felt need for a means to detect conditions that are capable of producing unrealistic or incorrect forces at the manually-operable controls and to abort the control loading system before any incorrect force can be introduced to give the operator-pilot wrong information.
SUMMARY OF THE INVENTION
The invention includes a variety of features by means of which the desired control loading force is obtained under varying conditions of simulated flight. That many features of the invention are applicable to the simulation of vehicles other than aircraft will become apparent to those skilled in the art as the description proceeds.
Therefore, it is a principal object of the present invention to provided a control loading system of such high performance that devices to supplement a manually-operable control are unnecessary.
Another object of the present invention is to provide a means of detecting out-of-tolerance conditions within a control loading system and disabling the system when these conditions are detected.
Yet another object of this invention is to provide a control loading system adapted to test itself in order to verify that it is operating properly.
Briefly, a high performance control loading system constructed and arranged in accordance with the principles of the present invention will convey to manually-operable controls of a vehicle simulator a "feel" that matches the real world response of actual controls. The system includes means to generate a signal corresponding to a difference between an applied force and a required force, means to generate a force in the manually-operable vehicle controls that is responsive to the difference signal, and a force monitor means to detect deviations inforce magnitude from the force responsive to this difference signal.
Other objects, advantages and uses of the invention will become apparent and will appear hereinafter as the present description proceeds.
Accordingly, the invention includes features of construction, combination of elements, and arrangement of parts, which will be exemplified in the constructions hereinafter described in detail, and the scope of the invention will be indicated by the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and the objects of the invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram of a force feedback control loading system used in aircraft simulators and over which the present invention provides substantial improvement.
FIGS. 2, 2A and 2B are a block diagram of a presently preferred embodiment of a force feedback control loading system constructed and arranged in accordance with the present invention.
FIGS. 3, 3A and 3B are a block diagram of a presently preferred embodiment of a monitor circuit for use in connection with the circuit shown in FIG. 2.
FIGS. 4, 4A and 4B are a diagram of an "error" detector circuit in accordance with the invention.
FIGS. 5, 5A, 5B, 5C and 5D are a diagram of a self-test circuit and its interconnections with the "error" detector circuit shown in FIG. 4.
FIG. 6 is a diagram of a solenoid drive circuit in accordance with the invention.
DETAILED DESCRIPTION
Referred first to FIG. 1 of the drawings, a force feedback control loading system is shown in block diagram form to illustrate such a system as used in aircraft simulators today. In this system, a control stick 10 is used by a pilot trainee to perform the simulated flight maneuvers, and therefore, the control stick 10 must have a "feel" analogous to the control stick in an actual aircraft.
The proper resistance ("feel") at a control stick 10 for any given flight condition is produced in the following manner. The control stick 10 is connected to a force transducer 11 by a mechanical linkage 12. Therefore, any force 13 applied by the pilot trainee, not illustrated, is transmitted through the mechanical linkage 12 in order to apply a pushing or a pulling force on the force transducer 11.
The force transducer 11 converts any applied force 13 to an electrical signal which is carried by an electrical connection 14 to a junction 15. A computer 16 produces an electrical signal representative of the forces that would be present on the control surfaces of an aircraft due to the aircraft's dynamics during the maneuver being simulated.
Therefore, the computer 16 produces an electrical signal which is equal to the required force signal, which signal is carried over an electrical connection 17 to the same junction 15. With the electrical signal representative of the applied force arriving at the junction 15 over the connection 14 and the electrical signal representative of the required force arriving at the junction 15 over the connection 17, a signal is produced over a connection 18 which is representative of the difference between the required and the applied forces.
An amplifier 19 receives the difference signal over the connection 18 and produces a drive signal output over a connection 20 that commands a servo valve 21 to connect hydraulic oil under pressure to initiate operation of an actuator 22. The magnitude of the drive signal output from the amplifier 19 over the electrical connection 20 determines the amount of oil under pressure that is applied to each side of a piston (not shown) in the actuator 22.
A change in the amount of oil under pressure that is applied to each side of the piston in the actuator 22 will cause a movement of the piston that will exert a force through a mechanical linkage 23 to the force transducer 11. Since the force transducer 11 is connected also to the control stick 10 through the use of the mechanical linkage 12, any force developed by the actuator 22 is connected directly to the control stick 10.
In the absence of the applied force 13, the only forces acting on the control stick 10, therefore, correspond to the control surface forces resulting from the particular flight conditions. The computer 16 generates a signal representative of these forces, and this signal is connected to the junction 15 over the connection 17.
Since no applied force 13 is present, the difference signal developed over the connection 18 will be the required force signal. This signal will drive the servo valve 21 to produce the required force at the actuator 22. This force is transmitted through the linkage 23, the force transducer 11, and through the linkage 12 to the control stick 10. Thus, proper loading of the control stick 10 is provided.
When a force 13 is applied to the control stick 10, the force transducer 11 produces an electrical signal over the connection 14 that is representative of the difference in forces on the opposing sides of the force transducer 11, i.e., in the mechanical linkages 12 and 23, respectively. This electrical signal is connected to the junction 15 over the connection 14 where it is compared to the computer-generated force signal that is required for a given flight maneuver.
The signal on the connection 18 that corresponds to the difference between the required force and the force on the force transducer 11 is used to drive the servo valve 21. The servo valve 21 "commands" the actuator 22 to generate a force whose magnitude is the difference between the force 13 applied to the control stick 10 by the pilot and the required force generated by the computer 16.
Responsive to the "command" by the servo valve 21, the force developed by the actuator 22 is transmitted to the control stick 10 by the mechanical linkages 12 and 23, respectively. Therefore, the necessary force to simulate a given flight maneuver will be present at the control stick 10.
Referring now to FIG. 2 of the drawings, the presently preferred embodiment of the invention is shown in block diagram form to illustrate its respective component parts. The same reference numerals are used in the respective figures of the drawings to illustrate the same or comparable component parts.
Contrary to the prior art as shown in FIG. 1, a compare circuit at the junction 15 produces a signal output that is representative of the difference between the applied force and the required force. This difference signal output is connected over the connection 18 to, first, an amplifier circuit 19 in order to produce a drive signal for the servo valve 21 which generates the proper force in the actuator 22 and, second, a monitor circuit 25 which monitors the rate of change of the drive signal and the magnitude of the difference signal output.
The drive signal from the amplifier circuit 19 is connected to a switch 24 by a connection 20 and to the monitor circuit 25 by a connection 20A, instead of directly to the servo valve 21. The switch 24 is a normally-closed electrical switch that is controlled by the output of the monitor circuit 25.
The monitor circuit 25 monitors the rate of change of the drive signal from the amplifier circuit 19 and also the magnitude of the difference signal output from the compare circuit at the junction 15 and produces logic signal outputs, whose states depends upon the rate of change of the drive signal from the amplifier circuit 19 and the magnitude of the difference signal output. If the rate of change of the drive signal and the magnitude of the difference signal are not of sufficient level to cause excessive forces to be produced by the actuator 22, the logic signals output from the monitor circuit 25 will "command" the electrical switch 24 and an abort manifold 26 to assume their normal states. The output logic signals from the monitor circuit 25 are connected over a connection 27 to the abort manifold 26, and the output logic signals also are connected by means of a connection 29 to the electrical switch 24.
The electrical switch 24 is closed in its normal state, and therefore, the drive signal from the amplifier circuit 19 is connected directly to the servo valve 21. In addition, the abort manifold 26, in its normal state, allows hydraulic oil under pressure to flow to the actuator 22 as dictated by the servo valve 21.
On the other hand, when the monitor circuit 25 "senses" a rate of change of the drive signal from the amplifier circuit 19 or a magnitude of the difference signal output that is capable of creating excessive force levels at the control stick 10, the logic signals from the monitor circuit 25 will change state and, thereby, cause the electrical switch 24 to open and, also, will cause the abort manifold 26 to transfer to its abort mode. Therefore, the servo valve 21 is disconnected from the drive signal from the amplifier circuit 19 because of the opening of the electrical switch 24, and in addition to disconnecting the drive signal from the amplifier circuit 19, the electrical switch 24 will ground the input to the servo valve 21. This causes the servo valve 21 to return quickly to its null position.
In its abort mode, the abort manifold 26 connects the chambers on each side of the actuator's piston together and dumps the supply pressure to the return. Therefore, the electrical and the hydraulic drives have been removed from the system, and the excessive force that was commanded by the drive signal from the amplifier circuit 19 will not be produced.
The abort maniforld 26 can be of any type available commercially for rapid control of hydraulic oil under pressure. For example, a suitable abort manifold for the high performance control loading system of the present invention is available from Control Concepts, Inc. in Newton, Pa.
Such an abort manifold, as contemplated for use with the present invention, would be connected to be responsive to a solenoid drive circuit 28 (FIG. 2). The solenoid drive circuit 28 is connected to be responsive to logic signals from the monitor circuit 25 over the connection 27, and the solenoid drive circuit 28 is connected to a solenoid 28A, as part of the abort manifold 26, by a series of control lines 28B.
A signal that is indicative of the required force is generated by the computer 16 in response to information from a position transducer 30 that is connected by a mechanical linkage 23A to the mechanical linkage 23. The position transducer 30 produces an electrical signal that is representative of the position of the moveable piston (not shown) in the actuator 22.
An output connection 31 connects the electrical signal from the position transducer 30 to the computer 16 by a connection 31A and to the monitor circuit 25 by a connection 31B.
The preferred embodiment of this invention, as just described in detail in connection with FIG. 2 of the drawings, provides a means of adequately protecting the pilot trainee from dangerous forces that can be produced by the usual control loading system. However, such protection can not be provided unless the monitor circuit 25, the electrical switch 24 and the principal components within the broken line 20B are operating properly. Therefore, an arrangement in accordance with the present invention also provides a means for verifying the operating status of these components and for prohibiting initialization of the system when they are not operating properly.
Referring now to FIG. 3 of the drawings, a block diagram shows the presently preferred embodiment of the monitor circuit 25 and how it interconnects with the electrical switch 24. The monitor circuit 25 monitors the output of the amplifier circuit 19 and the difference signal on the connection 18 in order to protect the pilot trainee from excessive force levels by removing the electrical and the hydraulic drive signals from the system when the rate of change of the output of the amplifier circuit 19 and/or the difference signal on the connection 18 exceeds a predetermined limit.
In FIG. 3, the connection 20 connects the output drive signal from the amplifier circuit 19 to a differentiator circuit 33 to produce the time rate of change signal over the connection 34. The time rate of change signal over the connection 34 then is compared to a specified predetermined acceptable limit in a comparator circuit 35. The difference signal over the connection 18 is also compared to its specified predetermined acceptable limit in the comparator circuit 35.
The output from the comparator circuit 35 is connect-to to a connection 36 which, in turn, is connected to an input connection 37 of a flip-flop 38 and to the input connection 39 of an "OR" gate 40. The output of the comparator circuit 35 will assume a "low" logic level when either or both of its inputs over the connections 34 and 41 exceed a predetermined limit.
The other input to the "OR" gate 40 is a signal over a connection 42 representing the position of the actuator piston relative to the position of the electrically simulated "stops" (electrical "stops" correspond to mechanical travel limits in the actual aircraft). This signal on the connection 42 is produced by an "EXCLUSIVE OR" gate 43 and a comparator circuit 44, and its logic state is determined by the value of the position signal on the connection 31B with respect to the forward and aft "stop" position signals.
Specifically, the position signal on the connection 31B is compared to the "stop" position signals by the comparator circuit 44. A "low" level logic signal will be produced at the output of the comparator circuit 44 when the position signal on the connection 31B exceeds either one of the "stops" position signals. Therefore, a "low" signal at the output of the comparator circuit 44 signifies that the control is at a "stop", whereas a "high" signifies that the control is not at a "stop".
This signal on the connection 45 is then fed into the "EXCLUSIVE OR" gate 43. Because the other input to the gate 43 is tied to 5 volts, the signal produced by this gate is the inverse of signal 45.
The signal on 42 and the output of comparator circuit 35 are input to "OR" gate 40, and the output of gate 40 is then fed into "AND" gate 46. The second input to the "AND" gate 46 is a connection 47 to provide a signal representing the status of the power supplies used by the control loading system and will be a "low" level if one or more of these supplies are below a predetermined value. As previously stated, the output of the comparator circuit 35 will be a "low" logic signal when the time rate of change of the output of the amplifier 19 exceeds its acceptable limit and/or the difference signal on 18 exceeds its limit.
Therefore, the output of the "AND" gate 46 will be a "low" level if the output of the comparator circuit 35 is "low" level and the signal on 42 is a "low" level, and/or the output of the power monitor circuit 48 is a "low" level. This "low" at the output of "AND" 46 signifies an "error" is present within the system: The rate of change of the output of amplifier 19 exceeds its limit and/or the difference signal exceeds its limit and the control is not at a "stop", and/or one or more of the supply voltages are out of a predetermined tolerance.
On the other hand, if the control is at a "stop" (the signal on 42="high"), the output of the "OR" gate 40 will be a "high" level. Provided the power supplies are within their specified tolerances, the output of the "AND" gate 46 will also be "high".
Thus, the "high signal on the connection 42 serves to inhibit a "low" signal from the output of the comparator circuit 35 from reaching the "AND" gate 46 when the control is at an electrical "stop". This prevents the creation of a "low" ("error" present) signal at the output of the "AND" gate 46 which will result when the control "hits" an electrical "stop".
The output of the "AND" gate 46 is connected over a connection 49 to a flip-flop 50 which has been configured so its output is a "low" level when an "error" is present within the system (the signal or 49="low") and remains "low" until the "error" is corrected.
This "low" level signal at the output of the flip-flop 50 will activate the means used to remove the electrical and the hydraulic drive from the system. Therefore, the system of the present invention will be disabled any time an "error" is present within the system, and the pilot trainee will be protected from dangerous situations.
The pilot trainee can not be protected, however, if the "error" detection circuitry is not operating properly. Therefore, a self-test feature has been included.
The self-test is accomplished through the creation of a signal within the monitor circuit 25 that is capable of producing a rate of change signal at the output of differentiator circuit 33 that exceeds the specified limit set by comparator circuit 35 (an "error" condition), and monitoring of various signals to determine if the "error" was detected and whether proper actions were initiated.
If these actions do not occur, the control loading system can not be initialized. Since the test signal created by the monitor circuit 25 is generated when the control loading system power supplies are switched "on", the operating status of the monitor circuit 25 is verified before the system is allowed to initialize. Thus, the system can not be initialized unless the monitor circuit 25 is operating properly.
Still referring to FIG. 3 of the drawings, switching the control loading power supplies "on" causes a time delay circuit 51 to produce a signal output on a connection 52 representing a "low" logic level for a finite period of time, such as for example, approximately one second. Thereafter, the signal on the connection 52 switches to a "high" level.
The output signal from the time delay circuit 51 on the connection 52 is connected also to an "AND" gate 53. The other input to the "AND" gate 53 is over the connection 54 from the power monitor circuit 48, and the signal on connection 54 is a "low" if one or more of the power supplies are below a predetermined value.
Therefore, the output of the "AND" gate 53 will be a "low" logic level until the power supplies are all within tolerence and until the time delay signal from the time delay circuit 51 switches to a "high" logic level. Provided the power supplies are operating within tolerence, the output signal from the "AND" gate 53 will be a "low" to "high" transition approximately one second after power turn-on.
This transition from "low" to "high" will cause a maximum amplitude voltage spike at the output of the differentiator circuit 33 if the differentiator is functioning properly. This maximum amplitude voltage spike then should cause the output of the comparator circuit 35 to assume a "low" logic level due to the maximum amplitude voltage exceeding the specified predetermined limit. Thereafter, a "high" logic level is developed, because the voltage no longer exceeds the predetermined limit.
This "low" to "high" transition at the output of the comparator circuit 35 signifies that the differentiator circuit 33 and the comparator circuit 35 are functioning properly. Since the time delay output signal over the connection 52 serves to hold the output of the "AND" gate 53 "low" until after the power supplies have all reached their correct operating voltages, the "low" to "high" transition at the output of the comparator circuit 35 does indeed result from the "AND" gate 53 transitioning from "low" to "high" rather than the ambiguous operation of the differentiator circuit 33 and the comparator circuit 35 that can occur when the power is applied initially.
Therefore, the presence of a delayed "low" to "high" transition at the output of the comparator circuit 35 does indicate proper operation of the circuits 33 and 35. The output of the comparator circuit 35 then is connected into the flip-flop 38.
The flip-flop 38 serves as a latch to produce a "low" signal until the circuits 33 and 35 have been tested for proper operation. Therefore, if these circuits are not functioning properly, the output of the flip-flop circuit 38 will remain "low".
Obviously, this maintaining of the flip-flop 38 at a "low" logic level will produce a "low" logic level at the output of an "AND" gate 55. The flip-flop 50 needs to have a "low" to "high" transition from the "AND" gate 55 along with a "high" from the "AND" gate 46 in order to initialize the control loading system.
Upon an initial power-on, the "AND" gate 46 initially develops a signal at its output on the connection 49 that is a "low" logic level, because the power monitor signal 47 is "low" until the power supplies all reach their correct operating voltages. This "low" logic level from the "AND" gate 46 is latched by the flip-flop 50 until the output from the "AND" gate 46 goes to a "high" level and the other input to the flip-flop 50 switches from a "low" to a "high" level.
Consequently, the output of the flip-flop 50 will be at a "low" logic level just after the power-up situation occurs and will remain "low" if the circuits 33 and 35 are not functioning properly. Therefore, in this case, the control loading system can not be initialized.
At power-up, flip-flop 50 is also tested for proper operation. As previously specified, the output of flip-flop 50 will be a "low" level just after power-up. This output signal is fed along connection 56 to flip-flop 57 and "AND" gate 58. The other input to flip-flop 57 is the output of "AND" gate 53.
Flip-flop 57 is configured such that its output will go "low" when the output of "AND" gate 53 is "low", and will remain "low" until the output of "AND" gate 53 goes "high" and then the output from flip-flop 50 transitions "low" to "high". Thus, if flip-flop 50 is failed "high", the output of flip-flop 57 will go "low" at power-up, and will remain "low".
This occurs because the output of "AND" gate 53 is "low" for approximately one second after power-up, and this drives the output of flip-flop 57 "low". If flip-flop 50 is failed "high", a "low" to "high" transition will not be present at the input to flip-flop 57, and the output of flip-flop 57 will remain "low".
This will obviously create a "low" at the output of "AND" gate 58. This "low" is fed into the solenoid drive circuit 28, where it "commands" the abort manifold to assume its abort mode. Therefore, no hydraulic pressure will be applied, and the system will not be initialized.
In addition to testing the circuits 33 and 35 and the flip-flop 50 for proper operation, the electrical switch 24 is tested also. As stated previously in reference to this FIG. 3, the output signal from the flip-flop 50, over the connections 56 and 29, is at a "low" logic level upon an initial power-up and also any time an "error" is detected within the system.
A "low" logic level signal on the connection 29 is used to control the electrical switch 24 in order to create an open circuit between the amplifier circuit 19 and the servo valve 21 and, also, to ground the input to the servo valve 21. The self-test feature checks for proper operation of the electrical switch 24 and prohibits initialization of the control loading system if the electrical switch 24 is malfunctioning.
The operation of the electrical switch 24 is checked by comparing the difference in voltage across the switch 24. This is accomplished by subtracting the output of the electrical switch 24 from the input to the electrical switch 24 (the output from the amplifier circuit 19 as it appears on the connection 20). This is accomplished in a subtractor circuit 61.
The output from the subtractor circuit 61 is fed along a connection 62 to a comparator circuit 63, which compares this difference signal, over the connection 62, to approximately zero volts provided in the comparator circuit 63. The output from the comparator circuit 63 will be at a "low" logic level if the difference in voltage across the electrical switch 24 is approximately zero. This signifies that the electrical switch 24 is closed.
Conversely, a "high" logic level at the output connection 64 will signify that the electrical switch 24 is open. The signal, therefore, on the connection 64 (representing the status of the electrical switch 24) is connected to an "EXCLUSIVE OR" gate 65, the other input being on the connection 66 (which signal represents what the status of the electrical switch 24 should be: open or closed).
The output of the "EXCLUSIVE OR" gate 65, on a connection 67, will be a "high" logic level if the electrical switch 24 is operating properly, and the output on the connection 67 will be a "low" logic level if the electrical switch 24 is not operating properly. A "low" signal on the connection 67 will create a "low" logic level at the output of the "AND" gate 68, and likewise at the output of "AND" gate 55. As stated previously, the flip-flop circuit 50 requires a "low" to "high" transition in the logic levels from the "AND" gate 55 in order to initialize the control loading system, and this can not occur if the electrical switch 24 is not operating properly.
Alternatively, if the electrical switch 24 is operating properly, the "EXCLUSIVE OR" gate 65 will have an output signal on the connection 67 that is a "high" logic level. In addition, if the differentiator circuit 33 and the comparator circuit 35 are functioning properly, the output from the flip-flop circuit 38 will be a "high" logic level.
This "high" from the flip-flop 38 along with the "high" from the output of the "EXCLUSIVE OR" gate 65 will create a "high" at the output of the "AND" gate 68. The output of "AND" gate 68, along with the outputs from comparator circuits 44 and 69, is fed into "AND" gate 55. The output of the comparator circuit 44 represents the position of the control with respect to the electrical "stops", and is a "high" when the control is not at a "stop".
The output of the comparator circuit 69 represents the magnitude of the output of the amplifier circuit 19. If the magnitude of the output of the amplifier circuit 19 is greater than approximately zero volts, comparator circuit 69 will output a "low". Conversely, a "high" represents an output from the amplifier circuit 19 of approximately zero volts.
By moving the control throughout its operating range, a point can be found where the output of the amplifier circuit 19 is approximately zero volts. This will cause the output of the comparator circuit 69 to transition from "low" to "high". This transition will also be present at the output of the "AND" gate 55 as long as the differentiator circuit 33, the comparator circuit 35, and the switch 24 are operating properly (i.e., the output of the "AND" gate 68 is "high"), and the control is not at an electrical "stop".
This "low" to "high" t4ansition along with a "high" from the "AND" gate 46 (signifying that no "error" is present within the system) will produce a "high" at the output of the flip-flop 50. This "high" will allow initialization of the system because the required conditions have been met: no "error" present, the safety system is operational, the control is not at a "stop", and the output of the amplifier circuit 19 has approached zero volts (requiring the output of the amplifier circuit 19 to be approximately zero volts before initialization can occur, prevents the system from comming-on forcefully).
In view of the very positive contribution that these two features, that is, the "error" detection feature and the self-test feature, make to the high performance of a control loading system constructed and arranged in accordance with the principles of the present invention, more details of these two features are shown in FIG. 4 of the drawings.
Referring now to FIG. 4 of the drawings, the "error" detector feature is shown in more detail in this embodiment of of the invention as including the differentiator circuit 33, the comparator circuits 35 and 49, the "OR" gate 40, "EXCLUSIVE OR" gate 43, "AND" gate 46, and the flip-flop 50.
In the differentiator circuit 33, a capacitor 70 differentiates the output of the amplifier circuit 19 connected over the connection 20 and produces a time-rate-of-change of the signal on the connection 20 at the output of the amplifier 71 in FIG. 4. Two resistors 72 and 73, along with a capacitor 74 are included in this circuit for noise, scaling, and frequency roll-off considerations.
The time-rate-of-change signal that is developed by this circuit at a point 75 is connected by the connection 34 to the comparator circuit 35. Here, the individual comparators 76 and 77 compare the time-rate-of-change signal to predetermined positive and negative limits, the positive limit being preset by the values of resistors 78 and 79, respectively, and the negative limit being preset by resistors 80 and 81, respectively.
The comparator circuit 35 also utilizes the comparators 82 and 83 to compare the signal on 18 representing the difference in applied and required forces to predetermined positive and negative limits established by resistors 84 and 85, and 86 and 87, respectively. Comparators 76, 77, 82, and 83 are configured and connected in such a way that a "low" level logic signal will be created at point 88 if the time-rate-of change signal over connection 34 exceeds its predetermined limit and/or the difference signal on 18 exceeds its limit.
A "low" level logic signal at the point 88 signifies that an "error" is present within the control loading system. Two resistors 89 and 90, and a zener diode 91, serve to limit the voltage swing at the point 88 to transistor-to-transistor-logic levels, and it serves also to limit electrical current flow to the individual comparators 76, 77, 82, and 83. The logic signal at point 88 is fed via connection 37 to flip-flop 38, and over connection 39 to "OR" gate 40.
Comparator circuit 44 uses two comparators, 92 and 93, to determine the position of the control with respect to the position of the electrical "stops". Specifically, comparators 92 and 93 compare the position signal on 31 with the position of the forward and aft electrical "stops".
The comparators 92 and 93 are configured so that a "low" level logic signal will be produced at point 94 when the position signal on 31 exceeds either one of the "stops" position signals (i.e., the control is at a "stop"). Resistors 95 and 96, and zener diode 97, limit the voltage swing at point 94 to transistor-to-transistor-logic levels. The logic signal produced at point 94 is fed to "EXCLUSIVE OR" gate 43 and "AND" gate 55.
The "EXCLUSIVE OR" gate 43 serves to invert the logic signal present at point 94. Therefore, a "high" level signal at the output of gate 43 signifies that the control is at a "stop", whereas a "low" signifies that the control is not at a "stop". The output of the gate 43 is fed into the "OR" gate 40. The other input to the gate 40 is the output of the comparator circuit 35.
As previously specified, the output of the comparator circuit 35 will be a "low" level if there is an "error" within the system, and the output of the gate 43 will be "low" if the control is not at a "stop". COnsequently, the output of the gate 40 will be "low" only if there is an "error" within the system and the control is not at a "stop". This will obviously create a "low" signal at the output of the "AND" gate 46, which is then fed into the flip-flop 50.
The configuration of the flip-flop 50 is such that its output assumes a "low" logic level whenever a "low" signal is present at the output of the "AND" gate 46 (indicating: an "error" has been present and the control is not at a "stop"), and it remains "low" until the "error" has been corrected and the self-test conditions have been met. This "low" level logic signal is used to disable the control loading system by causing the electrical switch 24 to "open" and by causing the hydraulic abort manifold 26 to transfer to its abort mode whenever an "error" is present.
To explain in still further detail how the self-test feature of the present invention interacts with the "error" detector feature 98 just described in reference to FIG. 4, reference is now made to FIG. 5 of the drawings.
In FIG. 5, one component of the self-test feature of the present invention is provided by the time delay circuit 51. When the power supplies (there are several) to the control loading system of the opresent invention are switched "on", a "one-shot" monostable multivibrator circuit 99 will produce a signal on the connection 52 having a "low" logic level for a finite period of time, and then the signal on the connection 52 will switch automatically to a "high" logic level.
A resistor 100, a capacitor 101, and a diode 102 determine the period of time (approximately one second) that the signal on the connection 52 remains at a "low" logic level. A resistor 103 and a capacitor 104 in effect guarantee that the "one-shot" monostable multivibrator circuit 99 will produce a "low" to "high" transition at its output due to the capacitor 104 charging from a ground potential.
Two Schmitt triggers 105 and 106, respectively, serve as a means of producing clearly defined logic levels for use as an input to the "one-shot" monostable multivibrator circuit 99. The signal on the connection 52 at the output of the time delay circuit 51 is connected directly to the flip-flop 38 and also to the "AND" gate 53. The flip-flop 38 is configured such that its output will be at a "low" logic level when ever the signal on the connection 52 is also at a "low" logic level, and it will remain at this "low" logic level until the signal on the connection 52 has gone to a "high" logic level and the output of the comparator circuit 35 undergoes a "low" to "high" transition.
As described previously, a "low" to "high" transition at the output of the comparator circuit 35 approximately one second after the power supplies to the control loading system have been turned "on" signifies that the differentiator circuit 33 and comparator circuit 35 are functioning properly. The operating status of the circuits 33 and 35 is determined by a power monitor circuit 48, the time delay circuit 51, and the "AND" gate 53.
The power monitor circuit 48 monitors the respective power supplies, including the +15 v, -15 v and 5 v, used by the control loading system and produces a "low" level logic signal at a point 107 when one or more of the power supplies are below a predetermined operating voltage. This is accomplished by the use of a voltage reference source 108 and the respective comparators 109, 110, and 111.
The output of the voltage reference source 108 is compared to the voltage at the point 112 by the comparator 110, and the output of this voltage reference source 108 is compared to the voltage at a point 113 by a comparator circuit 111. The voltage at the point 112 is determined by two resistors 114 and 115, respectively, and the voltage present at the output of the +15 volt supply.
If the output of the +15 volt supply is below its acceptable operating value, the voltage at the point 113 will be less than the voltage from the voltage reference source 108, and this will produce a "low" logic level at the point 107. Similarly, if the output of the 5 volt supply is below is acceptable operating value, the voltage at the point 113, determined by two resistors 116 and 117, respectively, will be less than the reference voltage, and a "low" level logic signal will be produced at the point 107.
The voltage reference source 108 is used also in conjunction with the -15 volt supply and two resistors 118 and 119 to determine the voltage at a point 120. The voltage at the point 120 then is compared to the ground potential by the comparator 109, and a "low" level logic signal will be produced at the point 107 if the -15 volt supply is below its acceptable limit.
Two resistors 121 and 122 and a zener diode 123 serve to limit the voltage swing at the point 107 to transistor-to-transistor-logic levels and to limit the current flow to the comparators 109,110 and 111. Therefore, the signal output for the power monitor circuit 48 over the connection 54 will be a "low" logic level until all of the power supplies are within their specific operating ranges.
At the moment of start up, when the power is first turned "on", properly operating power supplies in a typical situation will reach their operating values in a few milliseconds. Therefore, the signal on the connection 54 at the output of the power monitor circuit 48 will be at a "low" logic level for a few milliseconds and then switch automatically to a "high" logic level. Since the signal on the connection 54 will be at a "high" logic level before the signal on the connection 52 switches from its "low" to "high" level, the output of the "AND" gate 53 will switch from a "low" to "high" logic level due to the switching of the signal on the connection 52.
The switching of the "AND" gate 53 will cause the differentiator circuit 33 to produce a maximum amplitude voltage spike which, in turn, causes the comparator circuit 35 to switch from a "low" to "high" logic level (FIG. 4). This signifies that the circuits 33 and 35 are functioning properly.
The flip-flop 38 is configured so that its output will be a "low" logic level until the signal on the connection 52 is a "high" logic level and the output of the comparator circuit 35 goes through its transition from "low" to "high". Therefore, the output of the flip-flop 38 will be at a "low" logic level until the differentiator circuit 33 and comparator circuit 35 have been tested. This creates a "low" logic level at the output of the "AND" gate 68, which is connected to the "AND" gate 55 which in turn is connected to flip-flop 50.
At the moment just after the power has been turned "on", the signal on the connection 54 is "low" and causes a "low" level logic signal at the output of the "AND" gate 46. This "low" level logic signal drives the output of the flip-flop 50 to a "low" logic level.
The output of the flip-flop circuit 50 is held "low" until a signal on the connection 49 is at a "high" logic level and then the output of the "AND" gate 55 switches from a "low" to "high" logic level. Since the output of the "AND" gate 55 can only switch from a "low" to "high" logic level if the differentiator circuit 33, comparator circuit 35, and the electrical switch 24 are functioning properly, and the control is not at a "stop", the control loading system is disabled until proper operation of the circuits 33 and 35, and the switch 24 is verified.
The operation of the electrical switch 24 is verified by the subtractor circuit 61, the comparator circuit 63 and the "EXCLUSIVE OR" gate 65. At initial power turnon, the "low" logic level that is present at the output of the flip-flop 50 will "command" the electrical switch 24 to "open".
The subtractor circuit 61 utilizes an amplifier circuit 127 to create a signal on the output connection 62, which is representative of the difference in voltage at the input to, and at the output of, the electrical switch 24. Four resistors 128, 129, 130 and 131 are used for scaling purposes to produce the difference signal on the connection 62. The signal on the connection 62 is connected directly to two comparators 132 and 133, respectively.
The signal on the connection 62 is compared to the voltage at two points 134 and 135 by the two comparators 132 and 133 respectively. Two resistors 136 and 137 are used to create a value of approximately 0+ volts at the point 134; two resistors 138 and 139 are used to create approximately 0- volts at the point 135.
If the magnitude of the signal on the connection 62 is greater than approximately zero volts, a "high" logic level signal will be produced at the output of the "OR" gate 140; signifying that the electrical switch 24 is "open". Conversely, if the magnitude of the signal on the connection 62 is approximately zero volts, a "low" level logic signal will be produced at the output of the gate 140 signifying that the electrical switch is "closed".
Four resistors 141, 142, 143 and 144 and two zener diodes 145 and 146 serve to limit the voltage swings at the two points 147 and 148, respectively, to transistor-to-transistor-logic levels. The output of the gate 140 is connected to the input of the "EXCLUSIVE OR" gate 65. The other input of the "EXCLUSIVE OR" gate 65 is the output of the flip-flop 50.
The signal output of the flip-flop 50 controls the operation of the electrical switch 24, and therefore, it represents what the status of the electrical switch 24 should be. If the electrical switch is operating properly; that is, if it is "open" because it has been "commanded" to open by the "low" level logic signal at the output of the flip-flop 50, the output of the "EXCLUSIVE OR" gate 65 will be "high".
This "high" level logic signal at the output of the "EXCLUSIVE OR" gate 65 along with the "high" from the flip-flop 38 that signifies proper operation of the differentiator circuit 33 and the comparator circuit 35 will create a "high" at the output of "AND" gate 68. If the control is not at a "stop", the signal on the connection 125 will also be a "high" level. Thus, the output of the "AND" gate 55 will "follow" the output of the comparator circuit 69.
As previously stated, by moving the control throughout its operation range, a position can be found where the output of the amplifier circuit 19 approaches zero volts. This will cause the output of the comparator circuit 69 to transition from a "low" to a "high" level. The comparator circuit 69 utilizes two comparators to determine the magnitude of the output of amplifier circuit 19.
Comparator 149 compares the output of the amplifier 19 to the voltage at point 150. Likewise, the comparator 151 compares the output of the amplifier 19 to the voltage at a point 152. The voltages at the points 150 and 152 are determined by the resistors 153, 154, 155, and 156, and correspond the 0+ volts and 0- volts respectively.
These two comparators 149 and 151 have been configured such that a "low" level signal will be produced at the point 157 if the output of the amplifier 19 is greater than approximately zero volts, and a "high" will be produced if the output of amplifier 19 is approximately zero volts. Resistors 158 and 159, and zener diode 160, servo to limit the voltage swing at point 157 to transistor-to-transistor-logic levels.
Since the output of the "AND" gate 55 will "follow" the output of the comparator circuit 69 if the switch 24 and the circuits 33 and 35 are operating properly, and the control is not at a "stop", a "low" to "high" transition can be produced at the output of the "AND" gate 55 by moving the control to the position where the output of the amplifier circuit 19 is approximately zero volts. Provided that there is no "error" present within the control loading system; that is, the signal on the connection 49 is a "high" logic level, this transition will cause the output of the flip-flop 50 to go to a "high" logic level. This "high" level signal will "command" the switch 24 to close, and this will allow the output of the amplifier circuit 19 to drive the servo valve 21. In addition to controlling the operation of the switch 24, the output of the flip-flop 50 is also used to control the solenoid of the abort manifold 26, thereby controlling whether the manifold is in its normal or its abort mode.
The output of the flip-flop 50 is fed to the flip-flop 57 and to the "AND" gate 58 in order to test the status of the flip-flop 50 before allowing the abort manifold 26 to transfer to its normal mode and introduce hydraulic pressure to the actuator 22. As indicated earlier, initial application of power will cause the output of the "AND" gate 53 to be a "low" level for approximately one second and then switch to a "high" level.
This "low" that is initially present at the output of the "AND" gate 53 will drive the output of the flip-flop 57 to a "low" level. This will create a "low" at the output of the "AND" gate 58, and this will "command" the abort manifold 26 to remain in its abort mode.
Flip-flop 57 is configured so that a "low" signal input over the connection 161 will drive the flip-flop output "low". The output will remain "low" until the input over the connection 161 goes to a "high" level and the input over the connection 162 transitions from a "low" to "high". Therefore, if the flip-flop 50 is failed to a "low" or "high" state, the necessary "transition" over the connection 162 will not be possible, and the output of the flip-flp 57 will remain "low". The "low" at the output of the flip-flop 57 will create a "low" at the output of the "AND" gate 58, which is fed into the solenoid drive circuit 28.
Referring now to FIG. 6, a "low" from the "AND" gate 58 will cause the two transistors 164 and 166 to remain off. Thus, the relay 164 will be de-energized, and the 24 volts will not be applied to the abort manifold solenoid 28A. Therefore, even if the transistor 164 or the relay 165 is malfunctioning in such a way that the 24 volts is applied to one of the solenoid's input terminals, the necessary ground is not applied to the other input terminal because the transistor 166 is off. Consequently, the solenoid 28A remains de-energized, and the manifold 26 remains in the abort mode.
On the other hand, if the flip-flop 50 is operating correctly, and all of the other initialization requirements have been met, a "low" to "high" transition will be present at the connection 162 of FIG. 5. This transition along with a "high" at the connection 161 will produce a "high" at the output of the "AND" gate 58.
The "high" at the output of the gate 58 will energize the solenoid 28A and the manifold 26 will transfer to its normal state, and the system will be operational. Hereafter, an "error" condition will produce a "low" at the output of the flip-flop 50; this will produce a "low" at the output of the "AND" gate 58, and the abort manifold will transfer to its abort mode.
In view of the preceding detailed description, it may be understood now by one skilled in this art that the present invention provides a technique that can be manufactured as a separate article of manufacture for attaching to the prior art systems, in an appropriate situation. For example, the component parts that are enclosed within the broken line 20B can be assembled and interconnected with suitable terminals and other connectors so that, as a separate article of manufacture, it can be coupled to a prior art control loading system as a retrofit to achieve a substantial improvement in its performance characteristics.
This invention has been described in terms of a control loading system as used in an aircraft simulator and in terms of a pilot trainee's control stick. However, it will be apparent readily to those skilled in the art that this invention can be practiced in any simulation condition where a control loading feedback loop is either desirable or is required.
It will be apparent also to those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention. For example, an accelerometer could be coupled to the mechanical linkage in order to sense the linkage acceleration. Also other electronic differentiating circuits could be employed readily. This invention, therefore, is intended to cover all other changes and modification as defined by the claims appended hereto.
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The control loading system described is capable of higher performance than anything available heretofor because of certain described features built in. The control loading system that is described includes a force transducer to develop an electrical signal corresponding to the force applied to the manually-operable controls of a vehicle simulator to develop a "feel" as sensed by an operator that matches the real world response of actual controls. A computer generates an electrical signal corresponding to the force required for these controls to give these realistic cues. A compare circuit generates a signal corresponding to the difference between the applied force and the required force, and the usual actuator device develops a force on the manually-operable vehicle controls in response to this difference signal. One of the more significant features of the invention is the monitor which detects deviations in force magnitude to disable the control loading system when the force detected exceeds a pre-set limit.
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RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Appl. No. 60/419,331, filed Oct. 17, 2002, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention pertains generally to fabrication techniques to be used for fabricating micro refractive, such as Fresnel, optics and compound optic comprising two or optical elements for short wavelength radiation. One application is the fabrication of the (AFO) described in U.S. patent application Ser. No. 10/134,026, which is incorporated herein by this reference in its entirety.
[0003] The Achromatic Fresnel Optic (AFO) is a multi, such as two, element compound optic that is comprised of a diffractive Fresnel zone plate and a one or more refractive Fresnel lenses. The optic is described in U.S. patent application Ser. No. 10/134,026, which is incorporated herein by this reference in its entirety. Further uses for the optic are described in U.S. patent application Ser. No. ______ filed on Oct. 10, 2003, by Wenbing Yun and Yuxin Wang, which is incorporated herein by this reference in its entirety.
[0004] Generally, the AFO is used for imaging short wavelength radiation including extreme ultraviolet (EUV) and x-ray radiation with wavelengths in the range of 0.02 nanometers (nm) to 20 μm. The diffractive element(s) is the primary focusing element, and the refractive element typically provides no or very little net focusing effect. It serves to correct the chromatic aberration of the zone plate.
SUMMARY OF THE INVENTION
[0005] The techniques for fabricating the zone plate element are well known in the art. They include, photo and electron-beam lithography techniques, and sputter-slice techniques. Challenges arise, however, when fabricating compound optics and Fresnel refractive optics for these short wavelength radiation applications.
[0006] Generally, the present invention describes methods of fabricating the refractive element(s) and aligning the elements in the compound optic and thus to the zone plate element. More specifically, the invention concerns the techniques that are used for fabricating micro refractive, such as Fresnel, optics and compound optics comprising two or optical elements for short wavelength radiation. One application is the fabrication of the Achromatic Fresnel Optic (AFO).
[0007] Techniques for fabricating the refractive element generally include: 1) ultra-high precision mechanical machining, e.g,. diamond turning; 2) lithographic techniques including. gray-scale lithography and multi-step lithographic processes; 3) high-energy beam machining, such as electron-beam, focused ion beam, laser, and plasma-beam machining; and 4) photo-induced chemical etching techniques. Also addressed are methods of aligning the two optical elements during fabrication and methods of maintaining the alignment during subsequent operation.
[0008] In general according to one aspect, the invention features a method for fabricating a compound optic for short wavelength radiation. The method comprises removing material of a substrate to form a surface profile of a first optical element of the compound optic. This can be performed mechanically or chemically. The second optical element of the compound optic is also formed on the substrate.
[0009] In general according to another aspect, the invention features a method for fabricating a compound optic for short wavelength radiation. The method comprises forming a surface profile of a first optical element of the compound optic on a substrate, while also forming a fiducial mark on the substrate. The second optical element of the compound optic is then formed by reference to the fiducial mark.
[0010] In general according to still another aspect, the invention features an optical element for short wavelength radiation. The element comprises concentric rings for focusing a beam of short wavelength radiation and segments extending at least partially radially between the concentric rings to support the rings.
[0011] A frame is also preferably provided. It extends around at least a portion of a perimeter of the concentric rings, with the segments extending between the rings and the frame to support the rings in the frame.
[0012] The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:
[0014] [0014]FIG. 1 is a side plan, cross sectional view of an compound optic or AFO;
[0015] [0015]FIGS. 2A and 2B are side plan, cross sectional views illustrating the fabrication of the refractive element using mechanical removal of material on the substrate;
[0016] FIGS. 3 A- 3 C are side plan, cross sectional views illustrating a gray-scale lithography method for the fabrication of the refractive element;
[0017] [0017]FIGS. 4A and 4B are side plan, cross sectional views illustrating a multi-step process for forming the refractive element;
[0018] [0018]FIGS. 5A and 5B are side plan, cross sectional views illustrating a process for forming the refractive element using a high energy beam 50 ;
[0019] FIGS. 6 A- 6 C are side plan, cross sectional views illustrating a process for forming the refractive element using photo-induced chemical etching;
[0020] FIGS. 7 A- 7 C are side plan, cross sectional views illustrating a process for aligning the diffractive zone plate element with the refractive Fresnel lens element;
[0021] [0021]FIG. 8 is a side plan, cross sectional view illustrating a process for fabricating the refractive Fresnel lens element using a hybrid fabrication solution; and
[0022] [0022]FIG. 9 is a schematic plan view of a free standing zone plate lens element according ot the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] [0023]FIG. 1 shows a compound optic or AFO 1 , to which the present invention is applicable in one example.
[0024] The exemplary compound optic 1 comprises a diffractive Fresnel zone plate element 5 and one or more refractive Fresnel lens elements 6 .
[0025] The compound optic 1 is shown fabricated on a single substrate 8 . In practice, the different elements 5 , 6 can also be fabricated on separated substrates, in other embodiments.
[0026] In the example in which the compound optic 1 is an AFO. It includes a primary focusing element, which is the diffractive Fresnel zone plate 5 , and chromatic dispersion compensating elements which is the refractive lenses 6 . The refractive lens 6 compensates for the chromatic dispersion of the zone plate 5 but with no or very small focusing effect.
[0027] For micro-imaging applications involving short wavelength radiation, i.e., radiation in the wavelength range of 0.02 nanometers (nm) to 20 nm, the width of the segments in the refractive lens 6 typically range from many millimeters in the center segments 110 to below 1 micrometer near the edge segments 112 . The profile accuracy required is about 10 nm and less. We will describe five methods that can be used to fabricate the required segments.
[0028] Ultra-High Precision Mechanical Machining
[0029] This method involves mechanical removal of material on a substrate in order to produce the desired lens profile.
[0030] [0030]FIGS. 2A and 2B illustrate the fabrication of the refractive element 6 on an unpatterned substrate 8 .
[0031] Specifically, FIG. 2A shows a sharp single-crystal diamond tool tip 10 of a diamond turning machine. The diamond tool tip 10 is controlled by a precision positioning system 111 and is driven along the surface 114 of the substrate 8 . In one example, the substrate is silicon wafer material or copper. The tool 10 remove there material of the substrate 8 typically while the substrate is turned or rotated around a center axis 116 to thereby perform the cut.
[0032] As shows in FIG. 2B, once the surface profile 110 , 112 is machined, the substrate 8 is typically thinned from the backside by removing the material in region 12 to thereby form an optical port to increase the transmission, if necessary. Finally, the second optical element, such as a diffractive zone plate element is then formed in the optical port 12 , in one example.
[0033] The precision of diamond machining tools can be as high as 10 nm and are able to machine most materials required for the refractive lens, such as silicon and copper.
[0034] Lithographic Fabrication
[0035] This method involves patterning a photoresist, then developing the resist, and transferring the profile of the developed resist to the substrate 8 . Two methods can be used with this technique.
[0036] FIGS. 3 A- 3 C show a gray-scale lithography method.
[0037] As shown in FIG. 3A, the substrate 8 is first coated with a layer of photoresist 14 . Then, the photoresist 14 is exposed with a spatially varying dosage (see dosage exposure profile 18 ) that corresponds the inverse of the desired surface profile.
[0038] Various types of exposure beams 16 can be used. Typically, the exposure beam is visible light, ultraviolet light, x-ray radiation, electrons and ions.
[0039] As shown in FIG. 3B, the resist 14 is then developed, yielding a profile 110 , 112 similar to the desired surface pattern.
[0040] As shown in FIG. 3C, the substrate 8 is then etched in the transfer etching step to produce the desired surface profile in the substrate.
[0041] It should be noted that the response of the photoresist 14 in exposure, development, and the transfer etching is non-linear. Therefore, careful calibration is required for high yields. This technique can produce resolution as high as tens of nanometers.
[0042] Finally, the refractive element 5 formed on the backside of the substrate 8 .
[0043] [0043]FIGS. 4A and 4B show an alternative method, using a multi-step process such as those used in semiconductor fabrication.
[0044] Here the smooth profile of the lens 6 needs to be approximated by a staircase pattern as shown in the FIG. 4A inset.
[0045] This is fabricated according to the following process as shown in FIG. 4B. A substrate 8 is first coated with a first layer of silicon 20 and then a layer of photoresist 22 . An etch stop layer is typically located between the silicon layer 20 and the substrate 8 . The photoresist 22 is exposed with a pattern (see exposure dosage profile 24 ) that corresponds to the lowest level of the staircase. After the resist 22 is developed, the first silicon layer 20 is etched to yield the lowest part of the staircase. The lens/substrate is then coated with, possibly, a thin etch stop layer and then resist 25 and polished to produce a flat surface, and then coated with another layer of silicon 26 . Another layer of photoresist 28 is coated over this silicon layer 26 and exposed with a pattern that corresponds to the next level of the staircase (see exposure dosage profile 30 ). A two-level staircase pattern will be produced after the resisted is developed and the silicon layer is etched (see reference numeral 60 ). This process is repeated until the desire staircase profile is obtained (see reference 62 ). The result pattern is encased in photoresist, and removing the photoresist will produce the refractive lens (see reference 64 ). The substrate 8 can be thinned or removed to reduce absorption.
[0046] Finally, the refractive element 5 formed on the backside of the substrate 8 .
[0047] High-Energy Beam Fabrication
[0048] [0048]FIGS. 5A and 5B show a method in which a high energy beam 50 of, but not limited to, laser, electron, ion, and plasma is used to ablate material on the substrate.
[0049] Specifically, as shown in FIG. 5A, high energy beam 50 is directed and scanned over the substrate 8 . Typically the beam 50 is a laser, electron, ion, and plasma beam that ablates material on the substrate surface. The relative movement between the beam and the substrate 8 is controlled, sometimes by rotating the substrate around its center axis in order to produce the desired profile 110 , 112 as shown in FIG. 5B.
[0050] This method is analogous to the diamond-turning machine in that the lens profile is produced directly on the substrate 8 in a 1-step process, except that energetic particles are used instead of a solid tool tip. This method can achieve about 1 micrometer accuracy with lasers and better than 10 nm accuracy with a focused ion beam. The substrate 8 of the finished lens can be thinned from the back to reduce absorption, and the refractive element 5 formed on the backside.
[0051] In the fabrication of the Fresnel refractive lens, the micromachining tools, such as focused ion beam milling, may need to be calibrated to fabricate the Fresnel lens with accurate linear dimensions, accurate depth profile, and without distortions.
[0052] For calibration, features, preferably linear scales 128 , are first fabricated on the substrate 8 by a suitable, well-calibrated process. One such process is electron beam lithography, which is well understood. Features produced by the micromachining tool, such as 110 , 112 are compared with the calibration features 128 to control and correct the calibration of the tool during the fabrication of those features.
[0053] Calibration features 128 in the form of linear scales in the plane of the lens or as trenches with an accurate depth profile for depth determination are preferably used.
[0054] Photo-Induced Chemical Etching
[0055] [0055]FIGS. 6A to 6 C show a method forforming the refractive element 6 that takes advantage of the property that the etching rate of certain materials is dramatically increased when heated or in liquid state. As a non-limiting example, we assume a refractive lens 6 made of silicon.
[0056] Referring to FIG. 6A, the silicon substrate 8 is placed in a chlorine gas environment 118 . A high-power laser spot 50 is then focused onto the surface of the silicon wafer 8 causing the surface to locally heat up and melt into a molten state. This causes the reaction rate with chlorine to increase twenty fold, and the molten zone is etched away at a much higher rate than the unheated region to yield the desired profile 110 , 112 as shown in FIG. 6B. This method is capable of producing features with up to 1 micrometer um accuracy in the transverse direction and 10 nm in the longitudinal direction.
[0057] As shown in FIG. 6C, backside thinning is further performed in some implementations to produce an optical port 72 to improve transmission.
[0058] Alignment of the Lens Elements of the Compound Optic
[0059] FIGS. 7 A- 7 C shows the alignment of the lens elements of the compound optic 1 .
[0060] As shown in FIG. 7A, the process begins typically with the first, refractive lens element 6 , which has been fabricated according to one of the previously defined processes.
[0061] The preferred method of aligning the zone plate 5 and the refractive lens 6 is to fabricate them on the same substrate 8 . As a non-limiting example, we will assume the refractive lens 6 is fabricated from silicon as shown in FIG. 7A.
[0062] As shown in FIG. 7B, a fiducial mark 70 is added to the refractive lens 6 . Specifically, in the example, the fiducial 70 is added to the center of the lens 6 . In practice, the placement of multiple fiducials can lead to higher accuracy.
[0063] Since the AFO is a transmissive lens, it is often advantageous to thin the substrate 8 to thereby fabricate an optical port 72 . This reduces absorption.
[0064] Once the substrate 8 is thinned to below 1 micrometer (um) in one implementation, the fiducial 70 can be imaged from the opposite side with a number of techniques, including but not limited to visible light. The zone plate element 5 is then fabricated in the optical port 72 such that it is centered at the fiducial mark 70 . The accuracy of the fiducial alignment can be on the order of tens of nanometers.
[0065] Hybrid Fabrication Techniques
[0066] [0066]FIG. 8 illustrates a hybrid fabrication process for fabrication of the refractive element 6 . Generally, in practice, it may prove advantageous to use a combination of different patterning techniques to fabricate the desired profile 110 , 112 of the Fresnel refractive lens 6 .
[0067] In the illustrated example, a binary process, such as electron beam lithography is first used to fabricate a pattern of concentric trenches 140 in the unpatterned substrate 8 - 1 . This produces a binary-patterned substrate 8 - 2 . Specifically, the binary pattern of concentric trenches represents the desired step function of the desired Fresnel lens.
[0068] A suitable micromaching process, such as focused ion beam milling, is subsequently used to produce the desired profile between steps.
[0069] Specifically, substrate material for removal 142 is targeted between the trenches 140 . The targeted material 142 is then removed using the focused ion beam 50 . This yield the desired profile 112 for refractive element 6 .
[0070] This approach has the advantage of combining the high-resolution patterning accuracy and depth control of electron beam lithography with the machining capabilities of focused ion beam milling. The gradual profile between zones is machined by focused ion beam milling, while it is extremely difficult to machine a vertical step with a great depth, which is accomplished with binary process, such as lithography.
[0071] [0071]FIG. 9 shows another embodiment of the diffractive or refractive element 5 , 6 . Specifically, the AFO 1 can be also realized by combining a free-standing Fresnel lens and/or a free-standing zone plate lens to reduce absorptive loss.
[0072] The free-standing zone plate and Fresnel lens are realized by addition of a support structure. In the illustrate example, radial spokes 152 are included with the typical pattern of concentric rings 150 associated with the zone plate 5 or Fresnel lens 6 . The spokes 152 connect and support the rings 150 and further connect the rings 150 to a surrounding frame 154 . Often the spokes are fabricated out of the same material (e.g., silicon or copper), and with the fabrication of rings. The spokes need not be continuous as shown but interrupted, such that only segments extend, at least partially in the radial direction, between each successive rings. In this way, all of the rings are connected through a series of spoke segments.
[0073] Typically a substrate support, which is needed for the fabrication, is removed in the final step leaving only self-supporting optical element 5 , 6 .
[0074] Common features in the support structure of the zone plate and the Fresnel lens can be used as fiducial markers to align both optical elements in respect to each other.
[0075] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. For example, typical scanning electron microscopes (SEM) have X-ray detectors (EDAX), which are used to identify materials being imaged. In the fluorescence spectrometer mode, the present invention is used as an element specific imaging attachment to a SEM.
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Methods for fabricating refractive element(s) and aligning the elements in a compound optic, typically to a zone plate element are disclosed. The techniques are used for fabricating micro refractive, such as Fresnel, optics and compound optics comprising two or more optical elements for short wavelength radiation. One application is the fabrication of the Achromatic Fresnel Optic (AFO). Techniques for fabricating the refractive element generally include: 1) ultra-high precision mechanical machining, e.g,. diamond turning; 2) lithographic techniques including. gray-scale lithography and multi-step lithographic processes; 3) high-energy beam machining, such as electron-beam, focused ion beam, laser, and plasma-beam machining; and 4) photo-induced chemical etching techniques. Also addressed are methods of aligning the two optical elements during fabrication and methods of maintaining the alignment during subsequent operation.
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BACKGROUND OF THE INVENTION
The invention relates to a hot gas or Stirling engine whose cylinder chambers are connected via heating tubes, which extend through a heating chamber, with regenerator-cooler units.
In the case of hot gas or Stirling engines whose cylinder chambers are connected via heating tubes, which extend through a heating chamber, with regenerator-cooler units, the regenerators have been generally limited to the axial flow type. In this respect, dependent on the design of the engine, a distinction has been made between cylindrical regenerators, which are respectively housed together with a separate cooler, that is disposed axially to the rear thereof, in their own housings arranged adjacent to the associated cylinders, on the one hand, and, on the other hand, annular cylindrical regenerators, which are respectively accommodated together with coolers, which are also annular cylindrical and are arranged thereunder, coaxially to the respectively associated cylinders in the engine housing. These two principles of design are illustrated together in FIG. 3.5.2-6 on page 112 of the publication DOE/NASA/0032-79/5, NASA CR-159744, MTI 79 ASE 101QT6, entitled "Automotive Stirling Engine Development Program" quarterly technical progress report for period July 1-Sept. 30, 1979, Mechanical Technology Incorporated, January 1980. The key feature of the two designs is that the respective regenerator is precisely fitted as a prefabricated unit in a receiving space the configuration and diameter of which are adapted to the dimensions of the regenerator. Furthermore, whatever its particular design, the regenerator is such that the working gas is only able to enter and leave via its ends and is only able to flow axially through it. The ultimate flow area available for the working gas was for this reason limited by the diameter of the receiving space for the regenerator.
Thus, especially in the case of hot gas or Stirling engines with a large displacement and with regenerators which, hence, have to be large as well, the relatively high working gas pressure of approximately 160 bar leads to mechanical strength problems in the regenerator housing and the engine housing, respectively. These problems have so far only been dealt with by having regenerator housings or engine housing which are either manufactured of materials with a greater resistance to pressure or with suitably thicker walls. Both features, however, ultimately led to a substantial increase in the price of the engine. In the case of annular cylindrical regenerators arranged coaxially to the cylinders any increase in the thickness of the walls in the engine housing led furthermore to an increase in the distance between the cylinders and consequently to an increase in the length of the engine, which was not desired.
Accordingly, it is an object of the present invention to provide a systematic modification of the regenerators so that the above mentioned disadvantageous features may be avoided in the case of engines with a large displacement and with high working gas pressures.
SUMMARY OF THE PRESENT INVENTION
The hot gas engine of the present invention is primarily characterized by an engine housing with receiving spaces; means defining cylinder chambers within the engine housing; regenerator-cooler units each comprising a tubular regenerator that is designed for radial flow of a working gas, whereby the regenerator is disposed within a respective one of the receiving spaces, and a cooler having a cooler housing; heating tubes connecting the cylinder chambers to the regenerator-cooler units; an outer annular duct defined outside each one of the regenerators, and an inner annular duct inside each one of the regenerators for supplying and discharging a working gas, whereby the outer and inner annular ducts are communicating with one another, and the outer annular duct communicates with the heating tubes.
In other words, tubular regenerators are employed, whereby each one is designed for radial flow and is disposed in the respective receiving space, and is surrounded by annular ducts serving as the inlet and outlet of the working gas both on its inside and on its outside.
In comparison with known regenerators of about the same size but with axial flow, this radial flow design and arrangement of the regenerators is responsible for a considerable increase in the flow area of the regenerator which in turn leads to a very great advantage for the Stirling process, since the internal flow losses are reduced, and accordingly there is an increase in the efficiency of the engine.
The selection of the size of the flow area will depend on the desired overall length of the tubular regenerator, and can easily be determined. The diameter of the regenerator will still be comparatively small and strength problems may be taken care of by the use of conventional means.
In a further embodiment, the regenerator is a thick-walled tube with an inner wall surface, an outer wall surface and a matrix of the tube being penetrable in a radial direction by a working gas whereby the working gas, when radially flowing from a hot expansion side of the hot gas engine to a cold compression side of the hot gas engine, transfers heat to the regenerator and, when flowing from the cold compression side of the engine to the hot expansion side of the hot gas engine, removes heat from the regenerator. The matrix of the tube may consist of knitted or woven thin wires wound to a tubular shape, of porous sintered ceramic materials or of foamed porous materials. It is also possible to have a mixture of randomly arranged fibers for the use as a matrix. Also, the matrix may consist of particles.
It is preferable, that the regenerator be provided with a heat shield at one end thereof that is facing the heating tubes.
In a further embodiment at least one of the regenerator-cooler units is incorporated in a separate housing provided within said engine housing; the respective regenerator-cooler unit further comprising: a fastening means comprising an outer annular support having a outer configuration corresponding to the further receiving space and having a radially inwardly extending support ring for supporting the regenerator thereon; a heat shield at an end of the outer annular support opposite the support ring; a core bolt extending in an axial direction of the outer annular support from the heat shield to the support ring and at an end adjacent to the support ring being provided with elastic intermediate sheets; and a tie rod disposed in a through bore of the core bolt for fastening the outer annular support, the heat shield and the core bolt to the cooler housing; whereby a radial space between the regenerator and the outer annular support respectively a further radial space between the regenerator and the core bolt define the outer and inner annular ducts.
In another preferred embodiment at least one of the receiving spaces is in the form of an annular passage coaxial to the cylinder chambers within the engine housing and is connected to the cooler, whereby the regenerator is disposed in the receiving space; the regenerator further comprises a terminating plate at one end thereof with which the regenerators are connected to the cooler, whereby the terminating plate has through holes for connecting the inner annular duct to a reservoir of the cooler and with tubes of the cooler for transporting a working gas communicating with the reservoir; and a heat shield disposed at an end opposite the terminating plate for radially and axially adjusting the regenerator in the receiving space.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in more detail with reference to the accompanying drawings, in which:
FIG. 1 shows a cross section of a diagrammatically illustrated hot gas or Stirling engine with a regenerator-cooler unit which is arranged in its own housing adjacent to one cylinder;
FIG. 2 shows the regenerator of FIG. 1 in more detail and on a larger scale;
FIG. 3 shows a cross-section of another embodiment of a Stirling engine which is also shown diagrammatically and represents a modification of the design illustrated in FIG. 1 and has a regenerator-cooler unit arranged coaxially to one of the cylinders; and
FIG. 4 shows a more detailed view of FIG. 3 on a larger scale.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described in detail with the aid of several specific embodiments utilizing FIGS. 1 through 4.
The hot gas or Stirling engines illustrated in FIGS. 1 and 3 have a conventional design with respect to the configuration and arrangement of the connecting rod system 1, the cylinders 2 with the pistons 3 therein, the piston rod seals 4, the ducts 5 for the working gas (that is to say the heating tubes and the connection ducts) and the heating system 6. In order to understand the invention it is only necessary to consider the regenerator-cooler units which will be described in more detail in the following paragraphs.
In the case of the hot gas or Stirling engine illustrated in FIG. 1 the cylinder chambers 7 are respectively connected via connection ducts 5/1 inside the cylinder heads, heating tubes 5/2 which are connected therewith and lead through a heating chamber 6/1, and transfer ducts 5/3 with a regenerator-cooler unit 8 which is arranged in a receiving space 17 of a separate housing 9 arranged adjacent to one cylinder 2. The regenerator-cooler unit housing 9 is secured to the engine housing 10 in a known manner which is not illustrated, such engine housing furthermore being of conventional design in other respects. Each regenerator-cooler unit 8 in this case consists of a regenerator 11 and a cooler 12 arranged underneath the regenerator 11.
The hot gas or Stirling engine illustrated in FIG. 3 deviates from the previous design since its cylinder chambers 7 are respectively connected via connection ducts 5/1 and heating tubes 5/2, which are jointed to the connection ducts 5/1 and lead through a heating chamber 6/1, and via transfer ducts 5/3 inside the cylinders with a regenerator-cooler unit 13, which is (a) coaxially outwardly arranged relative to a cylinder 2 in a receiving space 18 in the engine housing 14 which is suitably adapted and (b) consists of a regenerator 15 and of a cooler 16 which adjoins the lower part of the regenerator.
Whatever the type of engine provided, in accordance with the invention, tubular regenerators 11 (FIGS. 1 and 2) or, respectively, 15 (FIGS. 3 and 4) are utilized, which are designed for radial flow of the working gas, for instance helium, and with which in the respective receiving space 17 in the regenerator cooler unit housing 9 and, respectively, 18 in the engine housing 14 a respective inner and outer annular duct 19 and 20 (FIGS. 1 and 2) or respectively 21 and 22 (FIGS. 3 and 4) is associated that serve for the radial inlet and outlet flow of the working gas.
Basically each regenerator 11 and 15 consists of a thick-walled tube, whose inner wall surface 23 and whose outer wall surface 24 and furthermore the matrix or openwork array of the tube 25 allows the passage of the working gas in a radial direction. In this respect the working gas flowing from the hot expansion side of the engine into the receiving space 17 and, respectively, 18 and via the outer annular duct 19 and, respectively, 21 transfers its energy to the tube wall 23, 24 and 25 as it flows through it to the cold compression side of the engine. This energy is removed again by the working gas when flowing from the cold compression side of the engine by the cooler 12 and, respectively, 16 and through the inner annular ducts 20 and, respectively, 22 through the tube wall 23, 24 and 25 in the opposite direction.
The matrix or openwork of the tube wall 25 of the regenerator 11 and 15 may be manufactured of any suitable material in any suitable way for an acceptable resistance to flow, as for instance in the form of knitted or woven tubes, of porous sintered ceramic, or a porous foam material or indeed of a random fiber material or of particles.
In FIG. 2 an embodiment of the invention in the form of a regenerator 11 as in the engine in the accordance with FIG. 1 will be described in detail.
The heating tubes 5/2 are connected to the domed head 26 of the regenerator-cooler unit housing 9 and, via adjoining transfer ducts formed in the head 26, they communicate with the receiving space 17 of the housing 9 for the supply and removal of the working gas. Within the housing 9 the tubular regenerator 11 is received in a fastening means with which the regenerator is held in the correct position within the receiving space 17 on the cooler positioned underneath. The cooler is fastened to the housing 9 in a known manner not illustrated in detail. The device consists of an outer annular support 27 whose radially outward configuration and cross section (at 28) correspond to the receiving space 17 having a support ring 29 projecting radially inwardly at the lower end of the outer annular support 27. The support ring 29 has a circumferential groove 30 in its upper surface. The surface 30a of the groove supports the lower end of the regenerator 11 and the inner and outer edges 31 and 32 of the groove 30 serve to exactly position the regenerator 11 radially within the support 27. Furthermore, the fastening means consists of a plate-like heat shield 33 which, by means of a gasket ring 34 inserted in an annular groove 34a, bears sealingly on the upper end surface of the regenerator 11. Moreover, the fastening means has a core bolt 35 which at least partly extends longitudinally through the interior space of the regenerator 11. The bolt 35 is axially and radially fixed in a recess 36 of the heat shield 33. In the illustrated working embodiment the support 27 is screwed with a female thread 37, provided at its lower end, onto a male thread 39 provided at the upper end of the cooler housing 38 and it is pulled against the upper end surface 40 of the cooler housing 38. The cooler housing 38 is delimited at the top by a wall 41 in which tubes 42 for the working gas to be fed to the cooler 12 are mounted. This wall 41, which is fixedly connected to the cooler housing 38, constitutes an abutment, whose central blind hole thread 44 has a tie rod 45 screwed into it. The tie rod 45 functions to clamp the regenerator 11 via the heat shield 33 against the support 27 and to clamp the core bolt 35 via elastic intermediate sheets 43, which function as spacer elements, against the heat shield.
The radial space between the regenerator 11 and the internal surface 46 of the support 27 on the one hand and between the regenerator 11 and the outer surface 47 of the core bolt 35 on the other hand defines the outer and inner annular ducts 19 and 20. The annular ducts serve to supply and discharge the working gas to and from the radially outer and inner side of the regenerator 11.
In the working embodiment illustrated in FIGS. 3 and 4, the regenerator-cooler unit 13 is inserted in a cavity which is defined by an annular passage extending coaxially to the cylinder 2 in the engine housing 14 and constituting the receiving space 18, whereby the cooler 16 is mounted at the bottom of the passage 18. In this case the tubular regenerator 15 is--as illustrated in FIG. 4--attached to the upper end of the annular housing 48 of the cooler 16. For this purpose the lower termination of the regenerator 15 is in the form of a terminating plate 41, which is screwed to the upper wall 50 of the cooler 16 in which the tubes 51 for the working gas are mounted and which has through holes 52, to provide a connection between the inner annular duct 22 and a reservoir 53 in the wall 50 as a port for the working gas. At the top the regenerator 15 is radially and axially positioned by an annular heat shield 54. A gasket ring 55 prevents transfer of the working gas from the outer annular duct 21 to the inner annular duct 22. In order to allow a flow of the working gas between the transfer ducts 5/3, provided in the cylinder head 56 and communicating with the heating tubes 5/2, and the outer annular duct 21 about the regenerator 15, suitable recesses 58 are provided in the heat shield 54. The axial positioning of the regenerator-cooler unit 13, 15 and 16 is achieved by elastic thrust rings 59, which simultaneously function as gasket elements and which in an annular groove 60 of the cylinder head 56 act on a thrust ring 61 which is present at the top of the heat shield 54 and extends into the groove 60.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
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In a hot gas or Stirling engine conventional regenerators for engines with a large displacement, designed for axially directed flow and usually lacking sufficient mechanical strength with respect to the high working gas pressures, have been replaced by radial flow regenerators. In the respective receiving spaces, the radial flow regenerators are surrounded externally and internally by an annular duct for the supply and discharge of the working gas. Thus, it is possible to ensure a larger flow area for the working gas and to design the engine with the desired mechanical strength.
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CROSSREFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional application 60/368,026, filed Mar. 27, 2002, and is a continuation-in-part of U.S. utility application Ser. No. 10/243,561, “Device for Decontamination of Water,” filed Sep. 12, 2002, and is a continuation-in-part of U.S. utility application Ser. No. 11/099,824, “Method and Apparatus for Decontamination of Fluid,” filed Apr. 6, 2005, each of which is incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to a device for the decontamination of water, particularly of arsenic, heavy metals, hydrocarbons, tensides, phosphates, dies, suspended substances, toxic substances, other electrochemically cleavable substances and their compounds, by means of an electrolytic device. In addition this device can reduce CSB-values and can strip out chlorine and aromatics; even stubborn bacteria cultures such as vibrio cholera and enterococcus faecium can be extinguished and filtered out later. The present invention can provide for the treatment of contaminated water sources such as above ground and underground source drinking water purification, and for industrial and residential wastewater decontamination for discharge of the treated.
[0003] There is growing environmental and social pressure being applied to the nation's waterways. The growing demand on existing water sources is forcing the evaluation of previously unusable water sources for domestic needs. In addition, increasing pressure is being applied to all forms of treated effluent in the nation's waterways. Various contaminants such as heavy metals, arsenic, naturally occurring and industrial carcinogens, etc., are subject to increasingly strict regulatory requirements. Federal, state, and local governments are imposing maximum contamination levels for drinking water distribution and wastewater discharge into public and private waterways.
[0004] A need exists for economical and efficient methods and apparatuses for treating various wastewater and drinking water sources, which can reduce the amount of regulated contaminates below regulated and suggested maximum limits. Current methods and apparatuses generally address only single contaminants, and require constant monitoring, chemical addition, or multiple passes through a device to separate contaminants from the water. Methods and apparatuses with the capacity and flexibility to support throughputs ranging from 20 gallons an hour to 100,000 gallons an hour are desirable.
SUMMARY OF THE INVENTION
[0005] The invention relates to methods and devices for the decontamination of fluid, particularly the removal of heavy metals and/or arsenic and/or their compounds from water, by means of electrolysis, wherein the water to be purified subjected to electrodes of different polarities. The invention can include means for control of the pH of the fluid. The invention can also reduce the “hardness” of water by reducing the concentration of constituents such as calcium, magnesium, or alkalinity in water. The invention can also include control systems that allow self-cleaning of electrodes, self-cleaning of filters, and automatic monitoring of maintenance conditions.
[0006] A method according to the present invention can comprise providing a reactor, having electrodes mounted therein and suitable for containing contaminant-laden fluid. The electrodes can be energized by applying an electrical potential across them, contributing to an electrolytic reaction with the contaminants. The electrolytic reaction produces a combination of electrode material and contaminant, resulting in flock which can be removed by filtering.
[0007] The electrical potential required to stimulate a certain current can depend on the spacing between electrodes. As electrodes are consumed by the reaction, the inter-electrode spacing increases, as does the required electrical potential. This potential can be monitored to provide an indication of the state of the electrodes. For example, a required potential over a threshold (or, equivalently, a resulting current below a threshold) can indicate that electrodes should be replaced.
[0008] Contaminants in the fluid can also adhere to the non-consumed electrodes, reducing the performance of the reactor. The electric potential can be reversed in polarity periodically. By reversing the polarity, the electrodes that had been subject to contamination are converted to electrodes that are consumed in the reaction. Consumption of electrode material can remove contamination from the electrode surface, allowing the reactor to be to some extent self-cleaning.
DESCRIPTION OF THE FIGURES
[0009] The invention is explained by using embodiment examples and corresponding drawings, which are incorporated into and form part of the specification.
[0010] FIG. 1 is a schematic illustration of an apparatus according to the present invention.
[0011] FIG. 2 ( a,b,c ) are schematic illustrations of various anode/cathode configurations in accordance with the present invention.
[0012] FIG. 3 is a schematic illustration of an apparatus according to the present invention.
DETAILED DESCRIPTION
[0000] Method of Decontaminating Fluid
[0013] The present invention provides methods and devices that facilitate the removal from water or other low-conductivity fluid of arsenic, heavy metals, hydrocarbons, tensides, phosphates, dies, suspended substances, toxic substances, electrochemically cleavable substances, and their compounds. The present invention can also reduce CSB-values and strip out chlorine and aromatics; even stubborn bacteria cultures such as vibrio cholera and enterococcus faecium can be extinguished and filtered out later. The present invention can also neutralize scents. Unlike previous approaches, the present invention does not require the use of membranes, chemicals, micro filtration, or specialty materials or alloys for anodes and cathode construction. The present invention can be realized with simple construction methods, and is flexible enough support a variety of design options.
[0014] The present invention can be used in both open system, partially open system, and closed system methods. An open system method is one where fluid to be treated is exposed to the atmosphere, and is not under pressure. A closed system method is one where fluid to be treated is not exposed to the atmosphere, and is generally under pressure. A partially open system has part of the system at atmospheric pressure; e.g., a reaction vessel can be open to the atmosphere, while the rest of the system closed and pressurized. Any of the methods can be practiced with an apparatus such as that shown schematically in FIG. 1 . Contaminated fluid enters a reactor 101 at an inlet 108 thereto. The reactor 101 comprises one or more anodes and one or more cathodes, and an electrical system adapted to supply electrical current through the fluid via the anodes and cathodes. The electrolytic reaction in the reactor 101 binds the contaminant into a flock material, which is passed with the remaining fluid to a flock removal subsystem 102 . A flock removal subsystem 102 can comprise a holding vessel 103 and a filter 103 . After the flock is removed, the remaining fluid, cleaned of the contaminant, exits the apparatus via an outlet 109 . The invention can also comprise control of the pH of the reaction, described below.
[0015] An open system method of decontaminating fluid according to the present invention comprises fluid processing through a reactor. The fluid is passed between a reactor anode and a reactor cathode subject to electrical potential and for an amount of time effective to separate the contaminants from the fluid. The reaction can increase the pH of the fluid. The contaminants and fluid form into a flock material and small amounts of O2 and H2. The fluid and the flock can then be passed to a holding vessel. The holding vessel can comprise a hollow container which adds residence time to the flock building process. An amount of time suitable for the flock building process can elapse, and then the fluid and the contaminants can be passed to a filter. As the fluid and flock flow through the filter, the filter material can trap the flock and the purified fluid passes through the filter. In an open system, pumps can be used to transfer fluid from the reactor to the holding vessel, and from the holding vessel to the filter.
[0016] A closed system method of decontaminating water according to the present invention comprises fluid processing through a reactor such as those described herein. The water is passed between a reactor anode and a reactor cathode subject to electrical potential and for an amount of time effective to separate the contaminants from the fluid. The contaminants and fluid form into a flock material and small amounts of O2 and H2. The closed reaction vessel can have means of venting gasses built up within the closed system. The fluid and the flock can be passed to a closed holding vessel. The holding vessel can comprise an empty container which adds residence time to the flock building process. An amount of time suitable for the flock building process can elapse, and then the fluid and the contaminants can be passed to a filter. As the fluid and flock flow through the filter, the filter material traps the flock and the purified fluid passes through the filter. In a closed system, generally the fluid enters under pressure, and that pressure causes the fluid to flow through the reactor, the holding vessel, and the filter.
[0017] Reactors suitable for the present invention can comprise various configurations. Contaminated fluid passes between anodes and cathodes. The material comprising the anodes and cathodes, the separation between the anodes and cathodes, and the electrical energization of the anodes and cathodes can affect the performance of the reactor. FIG. 2 ( a,b,c ) are schematic illustrations of various anode/cathode configurations. The configurations in the figures are for illustration only; those skilled in the art will appreciate other configurations that are suitable. In FIG. 2a , substantially flat plates comprise the anodes 202 and cathodes 203 . The anodes 202 and cathodes 203 mount within a tank to form a reactor 201 . An electrical system 204 energizes the anodes 202 and cathodes 203 . In FIG. 2 b, an anode 212 mounts within a cathode 213 , shown in the figure as coaxial although that is not required, to form a reactor 211 . In FIG. 2 c, anodes 222 and cathode 223 are U-shaped, and mounted with a tank to form a reactor 221 .
[0018] Aluminum anodes and cathodes can be used to remove contaminates from drinking and waste water. The aluminum electrodes can be at least 95 % pure. In some applications the reaction will result in a 0.5 increase in pH values. The aluminum anodes can be consumed during the purification process. pH values are between 6.5-7.5 can foster efficient reaction. As the pH increases above 8.5, significant reduction in efficiency can occur and undesirable anode consumption can occur.
[0019] Iron anodes and cathodes can be used to remove contaminates from industrial and waste water. The iron can be at least 95% pure. In some applications the reaction will result in 0.5 increase in pH values. The iron anodes can be consumed during the purification process. The reaction can be less sensitive to pH values than that with aluminum anodes and cathodes. The working pH values can be between 4.5-9.5.
[0020] Carbon graphite anodes and cathodes can be used in the reactor, and can reduce liquid pH values. Also, carbon electrodes, especially when used as cathodes, can be less susceptible to electroplating or pacification which can reduce performance. These anodes and cathodes can be made from at least 99% pure carbon, converted to graphite through typical industry practices. If the starting PH value is below 7.0, graphite plates might not be needed for pH management. When the purification process occurs with iron or aluminum anodes and cathodes, there can be a 0.5 to 1.0 increase in pH. If the liquid is highly contaminated, the reaction power requirements can be high and the reaction time long; these can increase the pH. If the starting pH is above 8.0 it is common to either have a high percentage of graphite plates (over 25% of the total) or to have a two step process. The first step can be to have a graphite reaction only to reduce the pH to preferred working values (e.g., 6.0-8.0). This will reduce the pH value and permit the normal decontamination reaction to occur. In many applications a 20% graphite anode and cathode quantity will be adequate to maintain a constant pH value of the liquid. It is also possible to increase the pH reduction capacity by increasing the current applied to the graphite anodes and cathodes.
[0021] The desired proportions of anode and cathode materials can be determined experimentally. The input and output requirements can first be identified. Iron is more typical for industrial waste water applications. Aluminum is more typical for drinking water applications. In some cases it can be possible to use both aluminum and iron together. Next the incoming pH can be determined. If the value is 5.5 to 6.5, graphite anodes and cathodes might not be required. If the pH is between 6.5 to 7.5, about 20% graphite plates can be suitable. If the pH is above this it can be necessary to experimentally determine the amount of graphite required to reduce the pH to normal. In very high pH situation (e.g., greater than 8.5), a two step process can be necessary: a first step for pH reduction, and a second reduction for contaminant removal and, optionally, further pH control. The aluminum and iron anode and cathode ratios can be determined by the intended application and expected contaminants, and can be readily optimized experimentally.
[0022] Anodes and cathodes can have various shapes and surfaces, depending on the reactor design and performance desired. In some embodiments, anodes and cathodes can comprise solid, substantially impermeable, smooth plates. In other embodiments, anodes and cathodes can have other shapes (e.g., tubes or rods in an annular reactor). The anode and cathode surfaces in some embodiments can be non-smooth (e.g., corrugated, pleated, rough).
[0023] Anodes and cathodes can be spaced apart a distance according to the conductivity of the fluid. The fluid conductivity contributes to an electrical load on the power supply. In general, greater anode-cathode separation corresponds to greater power supply voltage required. In many applications, a 15 mm separation between anode and cathode is suitable. In some applications, a power supply required voltage of 10 VDC or more indicates that the anode-cathode separation is too large. In some applications, a power supply required voltage of 8 VDC or less indicates that the anode-cathode separation is too small. Anodes and cathodes can be paired in alternating sequence, although other arrangements, including unequal numbers of anodes and cathodes, can also be suitable.
[0024] The thicknesses of the anodes and cathodes can be in accordance with the overall structure of the reactor. In a reactor with parallel plate anodes and cathodes, the thickness can be established for convenience of manufacture and assembly. Since the flock production reaction consumes material from the anodes, anode thickness can affect the time between anode replacements. Since the flock production reaction does not consume material from the cathodes, cathode thickness is generally not critical to reactor lifetime.
[0025] The polarity of the electrical power supply can also be reversed from time to time. Reversing the polarity effectively exchanges the roles of the anodes and cathodes: anodes at one polarity become cathodes at the opposite polarity. Reversing the polarity can distribute the material consumption across all the electrodes, consuming from one set at one polarity, and from another set at the opposite polarity. This can lengthen the time between electrode replacements.
[0026] Reversing the polarity can also provide an automatic self cleaning of the reactor electrodes. When the cathode is changed into an anode, it begins the anode consumption process and can strip away any potential buildup of contaminants on the cathode. This polarity reversing cycle can occur every six hours in some applications. This will balance the reactor anode consumption upon both sets of electrodes. In highly contaminated environments this cycle time can be decreased. The buildup of contaminants on the cathode can be detected by monitoring the voltage demand on the power supply. A rapid increase in voltage required can indicate either increased anode-cathode separation or contaminant buildup on the cathode. Accordingly, an increase in voltage required can indicate that a polarity reversal is in order; if reversing the polarity does not decrease the voltage required, then the electrodes might need replacing (for example, if too much material has been consumed from their surfaces to maintain the desired separation).
[0027] The anodes and cathodes can be of any size, although it can be desirable to configure the reactor so that the anode and cathode surface area are as large as possible to increase the contaminant removal performance of the system. The total anode surface area can be approximately equal to the total cathode surface area, for example in a tank with parallel plate electrodes. The total surface areas can also be different, as might be the case in an annular reactor. Keeping some part of the electrodes out of the fluid can be desirable in some applications to prevent fluid damage of the electrical connections to the electrodes.
[0028] The present invention can be operated in both batch and continuous modes. In a batch mode, a reactor is filled with contaminated fluid and operated until a desired end state (e.g., a desired level of contaminant remaining). Batch operation allows precise control of operating parameters such as voltage and current to the electrodes. In a continuous mode, contaminated fluid is continuously communicated to a reactor, and decontaminated fluid is continuously removed from the reactor. A potential drawback to a continuous mode is that there can be blending of contaminated fluid with decontaminated fluid, lowering the effective performance of the reactor. Some reactor configurations can control the amount of blending to maintain consistent contaminant removal.
[0029] The holding tank size can be determined through experimental means. It can be designed to hold at least three minutes of reacted fluid to permit additional flock growth. In some instances it can be useful to provide additional flock growth time. Flock-laden fluid, such as fluid in a holding tank or in pipes, can be treated using any of a variety of techniques to encourage separation of flock and contaminants from the clean fluid. As an example, ultrasonic energy imposed on the fluid can encourage separation of the flock from the fluid, in some applications by differentially attracting flock. Flock having an electric charge can be separated electrostatically by means of an electric field. Charged flock particles moving (e.g., in a pipe) can be separated magnetically. Other flock particle drivers such as visible and infrared light, gravity, and pressure differentials, can also be used. The techniques described can be used alone or in combination with these or other techniques.
[0030] As an alternative to a holding tank, or in combination with a holding tank, a separator can be used to separate flock from treated fluid. Note that the separator can generate just a flock-enriched fluid portion and a flock-depleted fluid portion. A holding tank, filter, or combination thereof can be used to completely remove flock from the fluid. Separated flock, or flock-enriched fluid, can be routed to a reactor (the same as where it was initially generated, or another reactor), or to a holding tank or reservoir to promote mixing with fluid to be treated. It has been found that, in many applications, only a small portion of the flock generated binds contaminants. However, a large concentration of flock is desired to ensure that contaminants do bind with flock. Consequently, recycling flock with a separator can yield the desired high flock concentrations without requiring continuous high flock generation by the electrodes. System power requirements and electrode consumption can be reduced by such flock recycling. In operation, the flock generation in the reactor can be controlled (e.g., by controlling electrode voltage or current, electrode spacing, number of electrodes energized, type of electrodes energized, etc.) to produce the desired flock concentration. In a start-up phase, the electrodes can be controlled to generate a large amount of flock. As the flock flows through the reactor and is recycled, the control system can reduce the flock generation by the electrodes, maintaining the desired flock concentration (or other monitored characteristic) with reduced power and electrode consumption.
[0031] The various parameters of the reactor and the operating process parameters can be selected based on the desired performance characteristics. For example, a 2 million gallon per day capacity can require 4 reactors with 500 AMP capacity each, while a smaller 50 thousand gallon per day facility can require a single 50 AMP capacity reactor.
[0032] In some operating environments, precipitates such as calcium can form on the electrodes and reduce performance. Agitation of the affected electrodes, e.g., by mechanical vibration, can discourage precipitate formation, dislodge precipitate, or both. Similar results can be achieved by changing fluid flow rates, patterns, or pressures; by agitation of individual electrodes, electrode groups, or the whole reactor vessel; or by changing other properties such as fluid temperature in appropriate patterns, or by manual or automated scraping. Such agitation can be performed continuously, or can be performed periodically on a schedule determined by time or another property such as fluid volume through the reaction or flock produced by the reaction. Also, such agitation can be performed in response to an indication that precipitation has occurred, such as measurements of electrode mass or weight (an increase can indicate precipitate formed on the electrode), fluid flow rate and pressure (precipitate can clog fluid flow paths), electrode thickness (an increase can indicate precipitate on the electrode), system performance measurements, or other direct or indirect measurements of precipitate formation.
[0000] Subsystems
[0033] In some configurations, the fluid and flock are transported from the reaction location to a holding tank or a flock building area. This can be continuous, or can be periodic after a time delay or sensed reaction conditions. Transporting the fluid allows control of the exposure of the fluid to the reaction. A low sheer or “gentle” pump can be used to transfer the fluid to reduce any breaking up of the flock. Such a pump can comprise an inertial pump, with an open or closed impellor. The impellor diameter can depend on the flow requirements. The impellor can be driven at 1100 to 1200 RPM in some embodiments. Generally, impellor rates of below about 1700 RPM can be suitable.
[0034] The electrical control system can be configured so that the reactor plates are initially energized with a low voltage. The power can be gradually increased until a desired power level or reactor operating characteristic is reached. The gradual increase in power can require about a minute, or less, from start until full power. A gradual start can foster longer service life of the electronics and power supply in some embodiments.
[0035] The electrodes can be energized with alternating polarity. Periodically, for example at set time intervals or when certain reactor operating conditions are reached, the polarity of the voltage supplied to the electrodes can be changed, exchanging the roles of the anodes and cathodes. Reversing the polarity will not adversely affect the flock generation or contaminant removal process (assuming that the anodes and cathodes are configured such that each can fill each role). Reversing the polarity can extend the reactor or electrode life in some embodiments by exposing all of the electrodes to anode consumption. Also, reversing the polarity can foster self-cleaning of the electrodes. Contaminants or plating can build up on a cathode at one polarity; when the polarity is reversed, the cathode becomes an anode and begins to lose electrode material to the reaction. Contamination or plating attached to such material is consequently removed as part of the anode operation of the electrode. Polarity reversals every 1 to 6 hours can be suitable for some embodiments.
[0036] The pH of the fluid in the reactor can be controlled be monitoring the pH of the incoming fluid or the fluid in the reactor. If a pH increase is sensed, then current can be increased to electrodes containing carbon. If a pH decrease is sensed, then current to electrodes containing carbon be decreased. Also, the temperature of fluid in the reactor can be controlled. For example, heating fluid entering the reactor can improve reaction rates, and can encourage thorough mixing of the fluid with the reacting elements.
[0037] The generation of flock within the reactor is important to the effectiveness of the system. Insufficient flock can lead to low contaminant removal performance; excessive flock generation can require excessive power generation and reduced electrode life. The properties of fluid exiting the reactor can be monitored to determine the characteristics of flock generation, and those characteristics used in the control system to determine voltage, current, duty cycles, electrode spacing, activation of specific electrodes, etc. For example, a conventional turbidity measurement of fluid exiting the reactor can provide an estimate of flock generation. Other measurements can also be representative of flock generations, such as fluid density, viscosity, acoustic properties. The level of flock generation desired can also be varied depending on the contamination level of the incoming fluid, on the desired contaminant removal properties, the available power, or a combination of those or other factors.
[0038] The electrical power supply to the electrodes can be monitored to derive information relative to maintenance of the system. The spacing between the electrodes contributes to a resistance presented to the power supply. As electrode material is consumed by the reaction, the spacing between the electrode surfaces can increase. The consequent increase in resistance can be sensed by monitoring the power supply. An excessive resistance, or power supply requirement, can indicate that the electrodes need replacing or the inter-electrode spacing needs maintenance.
[0039] Example System. FIG. 3 is a schematic illustration of an apparatus according to the present invention. The apparatus comprises a reactor 301 such as those discussed above, a filter subsystem 302 , a flock fluid vessel 304 , a pure fluid reservoir 305 , a disinfection subsystem 306 , and a filter press 307 , in fluid communication with each other via a distribution system 300 .
[0040] The electrode arrangement of the reactor 301 is shown schematically; any of the configurations described above can be used. A power supply and control system (not shown) energizes the electrodes, and can provide self-cleaning and maintenance signals as discussed above. Fluid to be decontaminated can be introduced to the reactor 301 via an inlet 331 . A sensor 311 can mount with the reactor to sense reactor conditions (e.g., pressure, fluid level, flow rate, pH, conductivity, dissolved oxygen, or purity).
[0041] After a suitable time exposed to the reactor 301 , fluid can be removed from the reactor 301 using a pump 308 such as a “gentle” pump described above. The pump 308 transfers fluid through the distribution system 300 to the filter subsystem 302 . The filter subsystem 302 removes flock from the fluid, passing purified fluid from the filter subsystem 302 to the pure fluid reservoir 305 . In the example embodiment shown, a disinfection system 306 such as, for example, chlorine or ultraviolet, can be used to further treat the purified fluid. Pure fluid can be removed from the pure fluid reservoir 305 using a pump 309 and passed to its eventual use. A sensor 313 can mount with the pure fluid reservoir 305 to sense conditions in the pure fluid reservoir (e.g., pressure, fluid level, flow rate, pH, conductivity, dissolved oxygen, or purity).
[0042] Periodically, the distribution system 300 can be configured so that pure fluid from the pure fluid reservoir 305 is pumped using a pump 310 through the distribution system 300 back into the filter subsystem 302 . This reverse fluid flow forces accumulated flock away from the filter subsystem. The distribution system 300 can be further configured to route the flock-laden fluid to a flock fluid vessel 304 . The flock fluid vessel 304 can have a sensor 312 to sense conditions in the flock fluid vessel (e.g., pressure, fluid level, flow rate, pH, conductivity, dissolved oxygen, or purity). After sufficient accumulation of flock-laden fluid in the flock fluid vessel 304 , the contents thereof can be routed to a filter press 307 where the solids can be compressed for easier handling and disposal. Excess fluid from the filter press can be discarded, routed back to the filter subsystem 302 , or routed back to the reactor 301 .
[0043] The filter subsystem 302 can comprise a plurality of filters in some embodiments. The distribution system 300 can be configured to allow forward flow (from the reactor 301 through the filter subsystem 302 ) through one subset of the plurality of filters, while contemporaneously allowing reverse flow (from the filter subsystem 302 to the flock fluid vessel 304 . In this way, “backwashing” of one of the plurality of filters can proceed while another filter is in normal operation, and so the reaction and filter process need not be halted to backwash a filter. In some embodiments, halting and restarting the purification process can lead to reduced performance.
[0044] Example System. FIG. 4 is a schematic illustration of a reactor tank suitable for some applications of the present invention. FIG. 4 shows a sectional view through the tank. The tank can comprise any of a variety shapes; for example, it can comprise a substantially cylindrical shape. A flow directing element, such as the center baffle shown in the figure, mounts within the tank. Electrodes can be placed in the tank to contact and treat fluid introduced thereto. A fluid inlet allows fluid to enter the tank near the bottom of the tank. Fluid outlets near the top of the tank allow fluid to exit the tank. Alternatively, one or more fluid outlets can be configured near the top of the baffle. In operation, fluid entering the tank must travel across electrodes at least from the bottom of the tank to the top, and generally will travel around the baffle as it does. Consequently, the fluid will pass in proximity to a significant area of electrodes, encouraging more complete reaction and contaminant removal. The electrolytic coagulation/flocculation process generates floc as a result of secondary reactions with the surrounding water. The process can utilize the water as an electrolytic medium to initially liberate metal (e.g., aluminum or iron) ions from the anode plate; these particles then form various water complex structures. The adequate flow of water between the anode and cathode provide transportation for the flock from the anode plate reaction site. In addition the appropriate and adequate water flow between the anode and the cathode promote floc and contaminant mixing resulting in improved water decontamination capacity and performance.
[0045] Example System. The reactor tank can be configured as part of a flow path. FIG. 5 ( a,b,c,d ) comprise schematic illustrations of various flow path configurations that can be suitable for use as reactor vessels. In FIG. 5 a, an anode mounts with a cathode such that they present substantially planar surfaces to each other. The separation between the planes can be determined from the desired electrode voltage and current and the characteristics of the specific electrode materials, the incoming fluid, and the desired performance. The fluid can be flowed between the two planes, passing a significant electrode area as it passes. One or both of the electrodes can be configured to have a nonplanar surface, which can encourage thorough mixing of the fluid with flock. FIG. 5 b shows an example of this, where both electrodes present a series of angular projections to each other, similar to teeth on a saw or ridges on a file. In FIG. 5 c, an anode and cathode present complex surfaces to each other, forming a serpentine path through which fluid flows. FIG. 5 d illustrates a section through a pipe shaped to provide a reactor tank. First and second ends are configured to mount with common cylindrical pipe. The circular end cross-sections are mated with two substantially planar portions (one shown in the figure), which portions face each other and comprise electrodes of the tank.
[0046] The particular sizes and equipment discussed above are cited merely to illustrate particular embodiments of the invention. It is contemplated that the use of the invention may involve components having different sizes and characteristics. It is intended that the scope of the invention be defined by the claims appended hereto.
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The invention relates to methods and devices for the decontamination of fluid, particularly the removal of heavy metals and/or arsenic and/or their compounds from water, by means of electrolysis, wherein the water to be purified subjected to electrodes of different polarities. The invention can include means for control of the pH of the fluid. The invention can also include control systems that allow self-cleaning of electrodes, self-cleaning of filters, and automatic monitoring of maintenance conditions.
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CROSS REFERENCE TO RELATED APPLICATIONS (IF APPLICABLE)
[0001] This application is a divisional application of U.S. patent application Ser. No. 13/191,554 entitled “Hyper-Condensate Recycler” filed on Jul. 27, 2011, which claims priority to U.S. Provisional Application Ser. No. 61/369,299 entitled “Hyper Condensate Recycler” filed on Jul. 30, 2010 the contents of both which are incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION
[0002] The subject matter disclosed herein relates to a device for use in a district steam heating system, and in particular to a device that recycles condensate to reduce consumption by end users and reduce discharges into sewer systems.
[0003] In large metropolitan areas, it is not uncommon for a central boiler system to be used to generate heat for multiple facilities in the surrounding area. This heating system is sometimes referred to as district heating. The steam is transported via insulated pipes to subscribing buildings, which purchase the steam from the steam utility. Similar to an electric meter, a steam meter measures the amount of steam used by a particular building and the building owner is charged on a periodic basis.
[0004] Some of the facilities that receive steam from the district heating system distribute the steam through the building steam-based space heating system, other facilities convert the steam into hot water in tube and shell heat exchangers. In the latter system, the hot water is then distributed by electrically driven pumps through-out the building for space heating and domestic hot water service. After the steam is utilized in either application, the resulting condensate is typically discharged to the city sewer system. In order to reduce the condensate temperature from 215-220 F to about 150 F (a typical city sewer requirement) the condensate is mixed with cold potable water.
[0005] The routing of the condensate into the sewer system is a convenient means for disposing of the condensate. However, the facility owner or the district heating system provider is charged a fee based on the amount of waste, including condensate water, that is discharged into the sewer system. Further, since cold water is mixed with the condensate to reduce the temperature, usable energy is wasted and discharge fees are increased.
[0006] Accordingly, while existing district heating systems are suitable for their intended purposes a need for improvement remains, particularly in reducing the amount of condensate discharge and in increasing the extraction of energy from the delivered steam.
BRIEF DESCRIPTION OF THE INVENTION
[0007] According to one aspect of the invention, a system for heating a facility is provided. The system includes a first inlet from a district heating system. A heating system is provided having a condensate outlet. A hyper-condensate recycler having a second inlet is coupled to the condensate outlet and a third inlet coupled to the first inlet, the hyper-condensate recycler having a first outlet. A separator having a fourth inlet is coupled to the first outlet, the separator further having a second outlet fluidly coupled to the first inlet.
[0008] According to another aspect of the invention, a system for recycling condensate within a heating system is provided. The system includes a heat exchanger having a steam inlet and a condensate outlet. A condensate tank is fluidly coupled to the heat exchanger. A hyper-condensate recycler having a first inlet is fluidly coupled to the steam inlet and a second inlet coupled to the condensate tank. A separator is fluidly coupled to receive a fluid output from the hyper-condensate recycler and first outlet fluidly coupled to the steam inlet and a second outlet fluidly coupled to the condensate tank.
[0009] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0010] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0011] FIG. 1 is a schematic view of a district heating system having a condensate recycling device in accordance with an embodiment of the invention;
[0012] FIG. 2 is a schematic view of a district heating system having a condensate recycling device in accordance with an embodiment of the invention; and
[0013] FIG. 3 is a side sectional view of a condensate recycling device for use in the district heating system of FIG. 1 or FIG. 2 .
[0014] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Embodiments of the present invention provide advantages in a condensate recycling device that allows for conversion of the internal energy of heated liquid into useful work. In embodiments of the invention, the heated liquid becomes a two-phase medium and enters a transonic phase, manifesting itself by converting thermal to kinetic energy and harvesting the energy release from the collapsed bubbles to increase the temperature in the outlet flow. This allows heat transfer from a lower temperature stream to a higher temperature stream to become possible. Advantages are gained by highly-efficient direct contact heating, and reducing or eliminating the expenditure of energy (hot water pump) while obtaining useful work. Embodiments of the condensate recycler allow for: the re-introduction of waste condensate into the steam/water mix thereby recovering the latent heat of vaporization of the condensate; the regeneration of steam from the mixed fluid at a desired pressure; reduction or elimination of water use to cool condensate prior to discharge to sewer; and reduction of overall steam consumption by the end users which consequently reduces water discharge to the sewer system.
[0016] Referring now to FIG. 1 and FIG. 3 , a system 20 in an end user facility is provided that receives steam from a district heating system 22 . The steam is supplied to a heating system 24 having a heat exchanger that transfers thermal energy from the steam to a building hot water system to the desired temperature. The steam condensate produced in the heating system 24 is collected in a condensate tank 26 . From the condensate tank 26 , a pump 28 transfers the condensate into the hyper-condensate recycler 30 . It should be appreciated that the system 20 may include additional control devices such as but not limited to flow meters 32 , temperature gauges 34 , pressure gages 36 and valves for example.
[0017] In parallel with the condensate from tank 26 , the hyper-condensate recycler receives steam from by-pass pipe 38 that is diverted from the incoming steam prior to the heating system 24 . The hyper-condensate recycler 30 is shown in FIG. 3 receives liquid condensate via a nozzle 40 and steam from conduit 38 via nozzle 42 . The condensate then enters a diffuser 44 having ribs 46 that induce rotational turbulent flow into the condensate flow. Similarly, the steam is directed into a diffuser 48 having multiple de Laval nozzles. In the exemplary embodiment, the concentric orifices 50 in the adjacent rim in lower fluid pressure areas are 8 millimeters in diameter while smaller 3-millimeter diameter orifices are arranged in higher-pressure areas.
[0018] From the diffusers 44 , the condensate flow enters an open mixing chamber 52 to be induced by de Laval orifices 50 from diffuser 48 . In the exemplary embodiment, the length of the mixing chamber 52 is 18-27 millimeters. In the mixing chamber 52 , a partial liquid stream 54 is recirculated from an exit nozzle 58 via a concentric conduit 56 . The mixed flow is further discharged into a co-axial nozzle that reduces the flow area of the rotational turbulent flow to tangentially compress the mixed flow towards the orifice of a de Laval nozzle 60 . A chamber 62 includes ribs 64 that have sharp edges that elevate the Reynolds number and induce turbulence.
[0019] A fluid flow then proceeds into the nozzle 58 where the compressed fluid expands. In the exemplary embodiment, the nozzle 58 is 7.5 millimeters from the de Laval nozzle 60 and the nozzle 58 have an angle of 48 degrees. At this point, a partial liquid stream is separated and recirculated into the conical conduit 56 . The partial liquid stream flows with a laminar flow through the conduit 56 to create an elevated liquid pressure at the conduit 56 output at chamber 52 .
[0020] From the nozzle 58 , the main liquid stream enters the exit discharge section 66 . The discharge section 66 has ribs 68 . The ribs 68 induce laminar flow in the exiting fluid. The liquid exiting the hyper-condensate recycler 30 has an increased temperature from the inlet temperature, and an increased pressure from the inlet pressure. In the exemplary embodiment, the inlet temperature of the condensate stream entering the nozzle 40 is between 220-280 Fahrenheit and a pressure between 9-50 psig. The exit temperature at discharge section 66 is 224-285 Fahrenheit and a pressure between 30-150 psig.
[0021] The output of the hyper-condensate recycler 30 is transferred to a separator 31 . The separator 31 separates liquid condensate and steam from the output of the hyper-condensate recycler 30 . The condensate is drained via conduit 33 and transferred back to condensate tank 26 . The separated steam is transferred via conduit 35 as recovered energy back to the inlet of heating system 24 where the separated steam is reused for providing thermal energy to the facility. It should be appreciated that this reuse of the separated steam reduces the consumption of steam from the district heating system.
[0022] Referring now to FIG. 2 , another embodiment of the system 20 is shown. In this embodiment, the system 20 receives steam from a district heating system via conduit 70 . The steam flows through a heat exchanger 72 that transfers thermal energy to a hot water heating loop 74 . The loop 74 is part of a heating system 76 that provides heat to desired locations within the facility. The heating system 76 may include additional control equipment such as pumps 78 , valves and gauges as is known in the art.
[0023] Once the thermal energy is transferred, the steam condenses and is transferred to a condensate tank 80 . The condensate is then flowed via conduit 82 via a pump 84 to the inlet of hyper-condensate recycler 30 . The hyper-condensate recycler 30 also receives steam from by-pass pipe 86 that is diverted from the incoming steam from conduit 70 upstream from the heat exchanger 72 . The hyper-condensate recycler 30 receives the steam and conduit and operates as described herein above to have an output fluid stream at a higher pressure and temperature than the incoming condensate. The output fluid stream is transferred to a separator 31 to separate condensate from the steam. The steam is transferred via conduit 88 back to conduit 70 , while the condensate is transferred from the separator 31 back to the condensate tank 80 via conduit 90 .
[0024] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
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A system for heating a facility is provided. The system includes a first inlet from a district heating system. A heating system is arranged having a condensate outlet. A hyper-condensate recycler is provided having a second inlet coupled to the condensate outlet and a third inlet coupled to the first inlet. The hyper-condensate recycler includes a first outlet. A separator having a fourth inlet is coupled to the first outlet, the separator further having a second outlet fluidly coupled to the first inlet.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The application claims priority to U.S. Provisional Patent Application No. 60/827,282 filed Sep. 28, 2006 and U.S. Provisional Patent Application No. 60/908,813 filed Mar. 29, 2007. These applications are incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a hose support system that can be used to support hoses or other wires, cables, etc., associated with medical devices. Suitably, the hose support system can be used to support the hose from a continuous positive airflow pressure (“CPAP”) device.
BACKGROUND
[0003] CPAP machines are utilized in the treatment of sleep apnea. Sleep apnea occurs when the muscles in the throat relax and the throat eventually closes off. After 20 to 30 seconds the brain senses oxygen deprivation and brings the patient to a lower level of sleep in order to start breathing again. Consequently, patients with sleep apnea often do not get enough deep sleep which results in daytime sleepiness and often other more serious health problems.
[0004] A CPAP machine is a simple respiratory ventilator used mainly by patients in the home treatment of sleep apnea. The CPAP machine prevents a patient's throat muscles from closing off by delivering a constant stream of compressed air via a mask connected to a hose. As a result, patients with sleep apnea are able to get more deep sleep because they are no longer cycling through the episodes of oxygen deprivation resulting from the throat muscles closing off.
[0005] The CPAP machine usually sits next to the patient's bed and is connected to a hose. The hose is generally around six feet in length and attaches to a rotating connector on the mask. The arrangement of the mask and connected hose presents common problems for patients as they use the CPAP machine during sleep, including: rolling over onto a hard, cold hose; rolling over while on the hose and yanking it loose from the mask or pulling the machine itself from its placement; getting the hose tangled in the headgear, around one's pillow or around one's neck; overflow air blowing onto an arm, a shoulder or a bed partner; mask becoming displaced or dislodged due to movement with a tangled hose.
[0006] A solution is needed whereby the hose of the CPAP is suspended away from the patient using the CPAP, allowing the patient a full range of movement without getting tangled in the hose. Similarly, such a solution is needed for patients hooked up to other medical devices attaching cords, tubes, wires, etc., to a patient.
SUMMARY OF THE INVENTION
[0007] The present invention provides a hose support system that can be used to support hoses, tubes, wires, cables, etc., from medical devices, such that a patient, particularly a patient in a bed, can have a full range of movement without getting tangled in the hoses, wires, cables, tubes, etc.
[0008] In one embodiment, the invention provides a hose support system comprising a base unit, a support arm and a flexible rod with fasteners attached. The support arm is connected to the base unit at one end and a movable joint portion at the other end. The movable joint has a receiving section for the flexible rod. The flexible rod is connected to the moveable joint by the receiving section. The base unit stabilizes the other connected components by placement under a mattress, a cushion or other weighted item next to both the medical device and the patient. Alternatively, the base unit may be built into or connected to a table or other base of a medical device that is situated near the patient. At least one fastener is attached to the flexible rod to hold the line (i.e., hose, cable, wire, tube, etc.) from the medical device up off of the bed which allows delivery of the precise amount of the line needed. The flexible rod extends over the patient's bed and is adjustable to a point above the patient's head so as to allow the line to hang down and not impede the patient's movements during sleep. When a hose delivering air is used (such as with a CPAP machine), this also helps to maintain a tight seal on the patient's mask attached to the hose. The hose support system can easily be assembled and disassembled without the use of tools, allowing the unit to be easily portable and easily stored.
[0009] In another embodiment, the invention provides a flexible air mask interface between a breathing mask and an air hose. The interface comprises a base and a flexible coupling cylinder connected to the base at one end and the air hose at another end. The base of the interface can be connected directly to a breathing mask, or can be connected to an elbow connection piece that is attached to a breathing mask. The base of the interface is designed in a way that is allows the base to rotate 360 degrees around the latitudinal axis of the base.
[0010] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of one embodiment of the hose support system shown secured in place under a bed, the hose support system including the base, support arm and flexible arm.
[0012] FIG. 2 is a partial perspective view of one embodiment of the hose support system shown secured in place under a bed, the hose support system including the base, support arm and flexible arm.
[0013] FIG. 3 is an exploded view of the support arm, the joint connecting cap, the joint connecting sleeve, and the moveable joint.
[0014] FIG. 4 is a close up view of the support arm and the joint connecting cap.
[0015] FIG. 5 is an exploded, partially cut-away view of the support arm, the joint connecting cap, the joint connecting sleeve, and the moveable joint.
[0016] FIG. 6 is an assembled cut-away view of the support arm, the joint connecting cap, the joint connecting sleeve, the moveable joint and the flexible arm.
[0017] FIG. 7 is a perspective view of the support arm, the joint connecting cap, the joint connecting sleeve, the moveable joint and the flexible arm.
[0018] FIG. 8 is a close up view of the flexible arm connectors in a connected configuration.
[0019] FIG. 9 is a close up view of the male and flexible arm connectors in an unconnected configuration.
[0020] FIG. 10 is a cut-away view of the flexible arm connectors in a connected configuration.
[0021] FIG. 11 is a perspective view of the base and support arm of the hose support system.
[0022] FIG. 12 is an exploded view of the base showing the base housing, the extended legs and the leg caps.
[0023] FIG. 13 is a perspective view of one embodiment of the hose support system shown secured in place under a bed, the hose support system including the base, support arm and flexible arm, with CPAP air hose being attached to the flexible arm.
[0024] FIG. 14 is a close up perspective view showing the CPAP air hose attached by the clips to the flexible arm.
[0025] FIG. 15 is a close up perspective view showing the CPAP air hose attached by the distal end clip to the flexible arm.
[0026] FIG. 16 is a close up of the end of the flexible arm with a distal end clip attaching the CPAP air hose to the flexible arm.
[0027] FIG. 17 is an exploded view of the air mask interface and the air mask.
[0028] FIG. 18 is a perspective view of the air mask interface connected directly to an air mask.
[0029] FIG. 19 is a top view of the air mask interface.
[0030] FIG. 20 is an exploded side view of the air mask interface.
[0031] FIG. 21 is a side view of a CPAP air hose attached to the flexible coupling cylinder of the air mask interface.
[0032] FIG. 22 is a side perspective view of an air mask attached to a connection elbow.
[0033] FIG. 23 is a side exploded view of an air mask attached to a connection elbow, a redirective connection elbow, the base on the flexible coupling cylinder of the air mask interface.
[0034] FIG. 24 is a side view of an air mask with a connection elbow attached to the redirective connection elbow attached to the air mask interface.
[0035] FIG. 25 is a side view of an air mask which is attached to another embodiment of an air mask interface comprising a first elbow connector which is attached to a second elbow connector.
[0036] FIG. 26 is a perspective view of an air mask which is attached in another embodiment of an air mask interface comprising a ball and socket interface.
[0037] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. The use of the term “attached” is meant that the elements listed as attached to each other are either secured to each other, affixed to each other, attached to each other, or integral to each other (i.e., present in the same piece).
DETAILED DESCRIPTION OF THE INVENTION
[0038] In one aspect, the present invention provides a hose support system that can be used to support hoses, tubes, wires, cables, etc., from medical devices. The hose support system is best show in FIGS. 1-17 .
[0039] In one embodiment, the hose support system 10 comprises a base 12 , support arm 14 , a moveable joint 16 , and a flexible arm 18 .
[0040] The base unit 12 consists of a housing connected to a leg unit for placing under a mattress that a patient lies on, and a central extension unit that is attached to a support arm. The leg section can be any structural arrangement that would provide support to the base unit 12 . The leg section can be a flat board or panel arrangement or can consist of extended legs. One embodiment of the base 12 can be seen in FIGS. 11-12 . In this embodiment the base 12 comprises a base housing 20 , a pair of extended legs 22 , and leg caps 24 . The components of the base 12 can be made of any sturdy material, including but not limited to, plastic, metal, ceramics, or other composites. The base housing 20 has a central extension 26 which has an aperture to receive one end of the support arm 14 , and two angled extensions 28 , each angled extension having an aperture to receive an extended leg 22 . The central extension 26 of the base unit can suitably be disposed at any angle with respect to the extended legs 22 . The extended legs 22 are received by the angled extensions 28 on one end of the extended legs 22 . The other end of the extended legs 22 can be capped by leg cap 24 sections. The extended legs 22 can be attached to the base housing 20 by a friction fit with the angled extensions 28 . The extended legs 22 may alternatively be attached by way of any standard interlocking tab means, or may be screwed into the angled extensions 28 by a threaded arrangement. The leg caps 24 can also be attached to the extended legs 22 by a friction fit, standard interlocking tabs, a screwed threaded arrangement, or any other connection arrangement. When the hose support system 10 is being used, the extended legs 22 of the base 12 are placed between the mattress and box spring of the bed the patient is sleeping on. The leg caps 24 of the base 12 help aid the extended legs 22 from slipping out from the mattresses. Alternative embodiments may allow for the base of the delivery system to attach, for example but not limited to, a medical device, a table next to a patient's bed, the patient's headboard or the ceiling above the patient's bed.
[0041] One end of the support arm 14 has a first and second end. The first end is received by the central extension 26 of the base housing 20 . This connection, in one embodiment, can be a movable joint connection. The support arm can be made of any sturdy material such as plastic, metal, ceramics, or other composites. The second end of the support arm 14 is attached to the moveable joint 16 . The arrangement is best shown in FIGS. 3-6 . In one embodiment, the end of the support arm 14 is connected to a joint connecting cap tube 30 . The joint connecting cap tube 30 has a sleeve section 100 having an inside 102 and a collar section 104 . The support arm 14 is received by the inside 102 of the sleeve section 100 . In one embodiment this connection can be a tab connection as shown in FIG. 4 , or can be a friction fit, screwed threaded arrangement, or any other suitable connection.
[0042] The movable joint portion 16 has a joint 32 , a stem 34 and a flexible arm receiving section 36 . In one embodiment, the stem 34 of the moveable joint 16 is secured to the support arm 14 by way of a joint connecting sleeve 38 . This arrangement is best shown in FIG. 6 . The joint connecting sleeve 38 has an outer collar 40 having an inside 106 and an outside 108 , and an inner collar 42 having an inside 110 and an outside 112 . The stem 34 of the movable joint 16 is received by the inside 106 of the inner collar 42 and an aperture in the support arm 14 . A portion of the joint connecting cap 30 is captured between the outside 112 of the inner collar 42 and the inside 106 of the outer collar 40 of the joint connecting sleeve 38 . In another arrangement, the stem 34 can be connected to the support arm 14 by a friction fit, a tabbed connection, a screwed threaded arrangement, or any other suitable connection. The stem could also, alternatively, be connected to the joint connection cap tube 30 or joint connecting sleeve 38 by any such arrangement. The movable joint portion 16 may be adjusted and moved to obtain an ideal position for hose delivery to the patient. The joint 32 may be a ball joint, a flexure joint, a spring joint or any other type of movable joint suitable to maximize the effectiveness of the hose delivery system.
[0043] The flexible arm receiving section 36 of the movable joint 16 is designed to receive and secure the flexible arm 18 . Suitably, the flexible arm receiving section 36 allows for the detachment of the flexible arm 18 for ease of travel and storage. The flexible arm 18 can be connected to the arm receiving section 36 by a friction fit, standard interlocking tabs, a screwed threaded arrangement, or any other connection arrangement.
[0044] The flexible arm 18 can suitably be one piece, or consist of a number of pieces, allowing the flexible arm to be collapsible for easy portability. The flexible arm 18 is suitably made from any durable flexible material, such as plastic, graphite composites, or other suitable material. When the flexible arm 18 is comprised of multiple sections 44 , the sections 44 may be inflexible, but connected by at least one flexible joint such that the multiple sections 44 are flexible relative to each other. At least one flexible joint may be made from any durable flexible material, such as plastic, graphite composites, or other suitable material. The flexible joint may include, but not be limited to, a ball and socket joint, a hinged joint, an accordion-fold joint, a spring-type joint, a swivel joint, or a pivot joint or any other suitable joint.
[0045] Alternatively, when the flexible arm 18 is comprised of multiple sections 44 , the sections 44 can be connected by male 46 and female 48 connecting sections. This arrangement is best shown in FIGS. 7-10 . The male connecting section 46 comprises a connection collar 50 and an elongated shaft 52 . The female connection section 48 comprises a connection collar 50 that has a hollow portion that is designed to receive the elongated shaft 52 of the male connecting section 46 . One of the connection collars 50 has a male threaded portion 54 and the other has a female threaded portion 56 . These portions 54 , 56 can be screwed together to connect the sections 44 of the flexible arm 18 .
[0046] A hose 60 can be secured to the flexible arm 18 by means of clips 62 . In one embodiment, as shown in FIG. 14 , the clips 62 comprise an arm securing section 150 , which receives a portion of the flexible arm 18 , and a hose securing section 152 which clips to a portion of the hose 60 . The fasteners of the flexible arm 18 can also include a distal end clip 154 , as shown in FIGS. 15-16 . The distal end clip 154 has an arm securing section 156 which receives a portion of the flexible arm 18 . The distal end clip 154 also comprises a hose clamp section 158 which has a first hose receiving section 160 which is connected to the arm securing section 156 at one end and is hingedly connected to a second hose receiving section 162 on the other end. The second hose receiving section 162 has an aperture 164 designed to receive a tab 166 on the arm securing section 156 of the distal end clip 154 . When the tab 166 is snapped into the aperture 164 , the second hose receiving section can be locked into place around a portion of the hose 60 . The distal end clip 164 is suitably positioned between an intermediate stopping section 168 and an end stopping section 170 of the flexible arm 18 . This positioning stops the distal end clip 164 from sliding down the flexible arm 18 . Alternatively, the hose 60 can be connected to the flexible arm 18 by any other suitable fastener means, including an enclosure that encircles the hose 60 that is closed by Velcro, a snap, an interlocking tab arrangement, or other suitable fastener arrangements. The flexible arm 18 holds the hose 60 off the bed and allows the hose 60 to slide through the clips 62 to constantly adjust to a patient's hose 60 needs.
[0047] In another embodiment of the invention, the invention provides a flexible air mask interface 70 between a breathing mask 72 and an air hose 60 . This aspect of the invention is best shown in FIGS. 17-24 . The flexible air mask interface 70 comprises a base 74 and a flexible coupling cylinder 76 connected to the base 74 at one end and the air hose 60 at another end. The base 74 of the flexible air mask interface 70 can also have small holes 82 that allow excess air to escape. The flexible coupling cylinder 76 is made from flexible material, including but not limited to corrugated material, that allows the cylinder 76 to bend in any direction. The flexible cylinder 76 can be made from any diameter necessary for the desired flexibility. The base 74 is designed in a way that it can rotate 360 degrees around the latitudinal axis of the base.
[0048] In one embodiment, the base 74 of the interface can be connected directly to a breathing mask 72 . In another embodiment the base 74 connects to a redirective connection elbow 78 that is connected to the standard connection elbow 80 of a breathing mask 72 . The redirective connection elbow 78 can be made of any sturdy material such as plastic.
[0049] In another alternative embodiment shown in FIG. 25 , the air mask interface can be comprised of at least two elbow connectors. A first elbow connector 84 is connected to an air hose 60 and a second elbow connector 86 is connected to the breathing mask 72 . Each end of the elbow connectors 84 , 86 can be rotationally connected to either each other, the air hose 60 and/or the breathing mask 72 . Each elbow can provide 360 degrees of rotation in two dimensions, so that when they are attached to each other they provide 360 degrees of three dimensional rotation. This allows for the freedom for the breathing mask 72 to be moved without tangling the air hose 60 .
[0050] In yet another alternative embodiment shown in FIG. 26 , the air mask interface can be comprised of a ball and socket interface 88 that is connected to an air hose 60 at one end and the breathing mask 72 at the other end. The ball and socket interface 88 allows for 360 degrees of three dimensional free rotation. This allows for the freedom for the breathing mask 72 to be moved without tangling the air hose 60 .
[0051] When the flexible air mask interface 70 of the invention is used with the hose support system 10 of the present invention, the air hose 60 extends straight up from the air mask interface to the flexible arm 18 of the hose support system 10 . In this arrangement, regardless of user movement in any direction, the air mask interface moves continuously to point in an upward direction, eliminating pull or drag caused by the pivot movement that is necessary when using a standard elbow connection 80 . The flexibility and continuous upward pointing allows for a smooth, unnoticeable transition for the user when moving from one position to another.
[0052] Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or figures. All of these different combinations constitute various alternative aspects of the present invention. Various features and advantages of the invention are set forth in the following claims.
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The present invention provides a hose support system that can be used to support hoses, tubes, wires, cables, etc., from medical devices. The invention comprises a base unit, a support arm and a flexible rod with fasteners attached. The base unit stabilizes the other connected components by placement under a mattress, a cushion or other weighted item next to both the medical device and the patient. At least one fastener is attached to the flexible rod to hold the line (i.e., hose, cable, wire, tube, etc.) from the medical device up off of the bed which allows delivery of the precise amount of the line needed.
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TECHNICAL FIELD
[0001] The present invention relates to a cell. More specifically, the present invention relates to a cell suited for various applications such as electronics, automobiles, and the like applications where cells are used.
BACKGROUND ART
[0002] Recently, increasing interest in environmental issues has brought a change of energy source from petroleum and coal to electricity in many industrial fields, and not only the fields of electronics such as mobile phones and laptop computers but also various other fields such as the auto industry and the aircraft industry have begun to use electric accumulators such as cells and capacitors. In keeping with this trend, materials for these electric accumulators have been the subject of intense studies.
[0003] Lithium ion cells are most popular among other electric accumulators. They are used as batteries in mobile phones and laptop computers, for example. Unfortunately, the charging and discharging capacity of lithium ion cells is not large enough, and this disadvantage has created a demand for novel cells with a larger charging and discharging capacity. Recently, lithium-air cells, which have a larger theoretical capacity than lithium ion cells, have received attention. There is a study on lithium-air cells which proposes the use of an organic electrolyte (see Non Patent Literature 1).
CITATION LIST
Non Patent Literature
[0004] Non Patent Literature 1: “All about novel models of accumulator batteries” (Kakushingata Chikudenchi no subete) written and edited by Zempachi Ogumi, Kogyo Chosakai Publishing Co., Ltd., 2010, 59-61
SUMMARY OF INVENTION
[0005] Technical Problem
[0006] Although high theoretical energy densities can be attained by lithium-air cells, actual cells have a much lower energy density. A principal reason for this is that pores of a porous cathode (air electrode) are blocked with a product (Li 2 O 2 or Li 2 O) of a discharge reaction at the cathode to prevent oxygen supply. Pore blocking with a reaction product also prevents sufficient charge as a result of preventing oxygen produced during charge from being discharged to the atmosphere. Another problem of lithium-air cells and other metal-air cells is the reliability and handleability. This is attributed to their unsealable structure designed as a mechanism with an air electrode into which and from which atmospheric oxygen is transported.
[0007] The present invention has been made under the foregoing circumstances, and an object of the present invention is to provide a cell that has a high theoretical voltage and theoretical capacity, and can be discharged and recharged multiple times.
[0008] Solution to Problem
[0009] The present inventors have studied various strategies to achieve cells that have a high theoretical voltage and theoretical capacity, and can be discharged and recharged multiple times, and found that in cells with a specific alkali metal compound as a cathode active material and an alkali metal as an anode active material, the cathode undergoes a reaction in which the alkali metal changes its form from A 2 O to A 2 O 2 (wherein A is an alkali metal atom) or vice versa when the cells are charged or discharged. The cells have a remarkably large theoretical capacity than lithium ion cells. Further, since oxygen molecules are not involved in charging/discharging, the cells can be designed as sealed structures, and thus are free from the above-mentioned problem attributed to blocking of air (oxygen) supply, unlike lithium-air cells. Additionally, the cells provide cost effective, environmentally-friendly benefits because they can be produced using materials other than rare metals. The above-mentioned effects can be achieved as long as the anode active material contains at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon. Thus, the present inventors have also found that the novel cells have these features, and completed the present invention.
[0010] Specifically, the present invention relates to a cell including: a cathode; an anode; and an electrolyte, wherein the cathode contains a cathode active material containing an alkali metal compound represented by the formula (1):
[0000] A x O y (1)
[0000] (wherein A is an alkali metal atom, x is 0.5 to 2.5, and y is 0.5 to 2.5), the anode contains an anode active material containing at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon, and the cathode, the anode, and the electrolyte are hermetically sealed in the cell.
[0011] The following description is offered to demonstrate the present invention in detail.
[0012] Combinations of two or more of preferable embodiments of the present invention described below are also preferable embodiments of the present invention.
[0013] A cell of the present invention includes: a cathode; an anode; and an electrolyte. The cathode contains a cathode active material containing an alkali metal compound represented by the formula (1):
[0000] A x O y (1)
[0000] (wherein A is an alkali metal atom, x is 0.5 to 2.5, and y is 0.5 to 2.5.) The anode contains an anode active material containing at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon. The cathode, the anode, and the electrolyte are hermetically sealed in the cell.
[0014] The cell of the present invention allows batteries including hermetically sealed cells because its particular cathode that contains a particular cathode active material containing a specific alkali metal compound allows charging and discharging in the absence of oxygen molecules. Additionally, the cell is cost-effective and environmentally compatible, and exhibits high cell performance.
[0015] The expression “the cathode, the anode, and the electrolyte are hermetically sealed” used herein refers to a structure in which, except for parts of the cathode and anode which are connected to an exterior part during discharge to the exterior and charge to the cell, the remaining parts of the cathode and anode, and the electrolyte are not exposed to the atmosphere.
[0016] The reactions at the electrodes and the overall reaction (the combination of these reactions) in the cell of the present invention include those represented below (A is an alkali metal atom). In all the reaction formulas, the forward reaction is a discharge reaction and the reverse reaction is a charge reaction.
[0000] Reaction at anode: A A + +e − (I)
[0000] Reaction at cathode: A 2 O 2 +2A + +2 e − 2A 2 O (II)
[0000] Overall reaction: A+1/2A 2 O 2 A 2 O (III)
[0017] No cells which make use of the combination of reactions at the cathode and the anode have been known, and the cell of the present invention is based on this novel principle.
[0018] For example, in the case where the alkali metal represented by A is lithium, the reactions can be specifically expressed as follows.
[0000] Reaction at anode: Li Li + +e −
[0000] Reaction at cathode: Li 2 O 2 +2Li + +2 e − 2Li 2 O
[0000] Overall reaction: Li+1/2Li 2 O 2 Li 2 O
[0019] The cathode of the cell of the present invention contains a cathode active material containing an alkali metal compound represented by the following formula (1):
[0000] A x O y (1)
[0000] (wherein A is an alkali metal atom, x is 0.5 to 2.5, and y is 0.5 to 2.5.)
[0020] Examples of alkali metal atoms for A in the formula (1) include Li, Na, K, Rb, Cs, and Fr. In terms of theoretical capacity, Li, Na, and K are preferred. More preferred are Li and Na, and still more preferred is Li.
[0021] In the formula (1), x is preferably 1 or 2, and y is preferably 1 or 2.
[0022] The alkali metal compound is more preferably an alkali metal oxide (A 2 O; namely x=2 and y=1), an alkali metal peroxide (A 2 O 2 ; namely x=2 and y=2), or an alkali metal superoxide (AO 2 ; namely x=1 and y=2), and still more preferably an alkali metal oxide or an alkali metal peroxide.
[0023] These alkali metal compounds may be used alone or in combination.
[0024] The cathode active material used in the cell of the present invention may further contain additional compounds other than the alkali metal compound, as long as it contains the alkali metal compound.
[0025] The cathode preferably includes a current collector and an active material layer, and the active material layer preferably contains the alkali metal compound represented by the formula (1) in an amount of 0.1% by mass or more relative to the mass of the active material layer.
[0026] The amount of the alkali metal compound represented by the formula (1) is more preferably 1% by mass or more, still more preferably 3% by mass or more, and particularly preferably 5% by mass or more in terms of theoretical capacity. The upper limit thereof is not particularly limited, but is preferably 99.99% by mass or less, and more preferably 99.9% by mass or less in terms of electrical conductivity.
[0027] In the case where the cathode (or the anode) includes a current collector and an active material layer, the “mass” of the active material layer herein refers to the mass of the overall cathode (or anode) except for the current collector.
[0028] Upon full charge, the cathode active material preferably contains an alkali metal peroxide represented by the following formula (2) in an amount of 1% by mass or more relative to the mass (100% by mass) of the active material layer of the cathode:
[0000] A 2 O 2 (2)
[0000] (wherein A is an alkali metal atom.) The presence of the alkali metal peroxide in such an amount means that the reaction of the reaction formula (II) is the principal reaction at the cathode of the cell of the present invention (the reaction accounts for 50% or more of all reactions at the cathode). In this case, the cell of the present invention more sufficiently exerts the above-mentioned advantages.
[0029] The amount of the alkali metal peroxide represented by the formula (2) relative to the mass of the active material layer of the cathode is more preferably 1 to 99.999% by mass, and still more preferably 20 to 99.9% by mass.
[0030] The same alkali metal atoms listed for A in the formula (1) can be mentioned as examples of alkali metal atoms for A in the formula (2).
[0031] Additionally, when the cell of the present invention is fully charged, the anode preferably contains an alkali metal at a ratio, determined on a molar basis relative to an alkali metal peroxide represented by the following formula (2) in the cathode, of not more than 100.
[0000] A 2 O 2 (2)
[0000] (In the formula, A is an alkali metal atom.)
[0032] In the cell of the present invention, the anode and the cathode undergo the reverse reactions of the reaction formulas (I) and (II) during charge. Upon full charge, the anode active material is completely converted from the alkali metal ion to the alkali metal, and the cathode active material is converted to A 2 O 2 represented by the formula (2). As described above, the cathode active material of the cell of the present invention may contain additional compounds other than the alkali metal compound. However, in order to satisfy the preferable condition that the principal reaction among all reactions at the cathode (the reaction which accounts for 50% or more of all reactions at the cathode) is the reaction represented by the reaction formula (II), A 2 O 2 preferably constitutes a predetermined proportion of the cathode upon full charge. Specifically, upon full charge, the molar ratio (A/A 2 O 2 ) of the alkali metal in the anode to the alkali metal peroxide represented by the formula (2) is preferably not more than 100. When the ratio (A/A 2 O 2 ) satisfies this condition, the above properties of the cell of present invention are more improved. The phrase “alkali metal in the anode” herein refers to all alkali metals involved in charging and discharging. Namely, the expression refers to all alkali metals in the anode upon full charge, excluding alkali metals which remain in the anode upon full discharge.
[0033] The cathode which contains a cathode active material containing an alkali metal compound, and the anode which contains an anode active material containing at least one of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon are preferably used as a cathode and an anode for primary and secondary cells.
[0034] Thus, an alkali metal compound is used as a cathode active material, and at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon is used as an anode active material. Because this feature eliminates the use of rare metals, the cell of the present invention can be produced at low costs and is advantageous as an element strategy.
[0035] The use of the alkali metal compound as a cathode and the alkali metal as an anode provides a cell with high electromotive force. In the case where the alkali metal is, for example, Li, the theoretical voltage is 2.87 V, and the theoretical energy density is 2566 Wh/kg. Thus, a cell that is excellent in both the theoretical voltage and energy density is provided. In particular, the energy density is remarkably higher than that of lithium ion cells, which are of the most popular type of cells.
[0036] In the cell of the present invention, the cathode material for the active material layer of the cathode is preferably a cathode mix essentially containing the cathode active material containing an alkali metal compound and further containing a catalyst for an electrode, a conductive auxiliary agent, and an organic compound. The cathode mix may further contain other components, if necessary.
[0037] The reaction from A 2 O to A 2 O 2 (reverse reaction) represented by the cathode reaction formula (II) in the cell of the present invention is a reaction that has been unknown so far. In order to smoothly charge and discharge the cell of the present invention, the overpotential of the reaction is preferably lower than that of the reverse reaction of the reactions (O 2 +4Li + +4e − 2Li 2 O) at the cathode of lithium-air cells. The use of a catalyst for an electrode in the active material layer of the cathode reduces the overpotential of the reaction from A 2 O to A 2 O 2 of the cathode reaction formula (II) (specifically, for example, the reaction from Li 2 O to Li 2 O 2 ).
[0038] In the cell of the present invention, even when a gas generating reaction (A 2 O→2A + +2e − +0.5O 2 ) occurs as a side-reaction of the reaction from A 2 O to A 2 O 2 (reverse reaction) of the cathode reaction formula (II), generated gas can be easily reduced to A 2 O or A 2 O 2 during discharge in the hermetically sealed cell by the reaction in accordance with the discharge reaction at the cathode of lithium-air cells.
[0039] Examples of the catalyst for an electrode include, but are not limited to, compounds containing an element of groups 1 to 17 of the periodic table and simple substances composed of such elements.
[0040] Examples of elements of groups 1 to 17 of the periodic table include Li, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Si, P, S, Ru, Rh, Pd, W, Re, Os, Ir, Pt, Au, O, S, F, Cl, and C. More preferred are elements of groups 5 to 11 of the periodic table. Still more preferred among the elements of groups 5 to 11 of the periodic table are V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Re, Os, Ir, Pt, Au, and C. Further preferred are Ag, Au, Cu, Fe, Mn, Co, Ni, and C.
[0041] The catalyst for an electrode can exert its catalytic ability even when it is in contact with particles of A 2 O or A 2 O 2 of the cathode reaction formula (II) or in the form of a solid solution in the crystal structure of A 2 O or A 2 O 2 .
[0042] The catalyst for an electrode may be a single oxide consisting of an oxide of a single element species represented by the following formula (3).
[0000] M a O b (3)
[0000] (In the formula, M is a metal atom other than alkali metal atoms; a is a value of 1 to 3; and b is a value of 1 to 4.)
[0043] Preferred examples of the metal atom other than alkali metal atoms include Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Si, P, and S. More preferred are V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Ag, Ta, and W. Still more preferred are Mn, Co, and Ni.
[0044] In the formula (3), a is preferably 1, 2, or 3, and b is preferably 1, 2, 3, or 4.
[0045] The single oxide is more preferably MO (namely, a=1 and b=1), MO 2 (namely, a=1 and b=2), M 2 O 3 (namely, a=2 and b=3), or M 3 O 4 (namely, a=3 and b=4).
[0046] Any catalysts for an electrode may be used alone or in combination.
[0047] The catalyst for an electrode may be a complex oxide containing two or more element species represented by the following formula (4).
[0000] QRO n (4)
[0000] (In the formula, Q is at least one selected from the group consisting of elements of groups 1 to 3 of the periodic table, R is at least one selected from the group consisting of elements of groups 4 to 15 of the periodic table, and n is a value of 1 to 3.)
[0048] Examples of elements of groups 1 to 3 of the periodic table for Q in the formula (4) include Li, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, and Nd. Elements of groups 1 and 2 are preferred among others. More preferred among the elements of groups 1 and 2 are Li and Sr.
[0049] Examples of elements of groups 4 to 16 of the periodic table for R in the formula (4) include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Sb, Hf, Ta, W, Pb, Bi, Si, P, and S. In particular, Fe and Co are preferred.
[0050] In the formula, n is a value of 1 to 3, and preferably a value of 2 to 3. More preferably, n is 2 or 2.5.
[0051] Any catalysts for an electrode may be used alone or in combination.
[0052] The amount of the catalyst for an electrode is preferably 0.1 to 99.9% by mass, more preferably 5 to 99.9% by mass, and still more preferably 10 to 99% by mass relative to the mass (100% by mass) of the active material layer of the cathode.
[0053] The catalyst for an electrode may be present on a later-described conductive auxiliary agent. The expression “the catalyst for an electrode is present on a conductive auxiliary agent” means that the conductive auxiliary agent is in the vicinity of or in contact with the catalyst for an electrode, or bound to the catalyst for an electrode, and that the catalyst for an electrode may be present not only on the surface of the conductive auxiliary agent, but also in the conductive auxiliary agent. In this case, the amount of the catalyst for an electrode (the total amount of compound(s) containing an element of any of groups 1 to 17 or such element (s), single oxide(s) represented by the formula (3) and complex oxide (s) represented by the formula (4)) is 0.01 to 300% by mass relative to 100% by mass of the conductive auxiliary agent. The amount is more preferably 0.1 to 150% by mass, still more preferably not less than 10% by mass, and particularly preferably not less than 40% by mass.
[0054] As processes for the production of a cathode using the cathode material, the following processes can be mentioned: Process 1 for preparing an alkali metal compound; Process 2 for preparing a cathode mix; and Process 3 for forming a cathode”.
[0055] In place of an alkali metal compound obtainable by “Process 1 for preparing an alkali metal compound”, a commercially available compound may be used. In this case, Process 1 can be omitted.
[0056] Preferably, Process 1 for preparing an alkali metal compound includes reacting an alkali metal with atmospheric oxygen or causing an alkali metal to react under an air atmosphere by heating, thereby providing an alkali metal compound. This step allows safe preparation of an alkali metal compound under comparatively mild conditions.
[0057] The reaction temperature is preferably 0° C. to 180° C. The period of reaction may be set according to factors such as the amount of alkali metal and the reaction temperature, but is preferably 0.5 to 20 hours.
[0058] In order to prepare a target alkali metal compound at a lower temperature in a short time, the alkali metal may be micronized into fine powder with an average particle size of 0.01 to 2 μm before the step of reacting an alkali metal in the air.
[0059] The micronization may be accomplished by any method, and a mortar, bead mill, ball mill, cutter mill, disc mill, stamp mil, hummer mill, jet mill, or the like can be used.
[0060] The step of micronizing an alkali metal into fine powder with an average particle size of 0.01 to 2 μm may be carried out at the same time as the step of reacting an alkali metal in the air. Namely, the alkali metal may be reacted in the air at the same time as micronizing the alkali metal.
[0061] The process for preparing an alkali metal compound may include a step of purifying the obtained alkali metal compound after the step of reacting an alkali metal in the air. Examples of the purification step include washing with water, treatment with an acid, washing with acetone, and washing with methanol.
[0062] In Process 2 for preparing a cathode mix, in the case where optional components such as a catalyst for an electrode, a conductive auxiliary agent, and an organic compound are used with the essential alkali metal compound, a cathode mix can be prepared by mixed these materials.
[0063] In the case where the cathode material (cathode mix) according to the present invention is prepared in the form of particles, the particles preferably have an average particle size of not more than 1000 μm.
[0064] The average particle size can be measured with a transmission electron microscope (TEM), a scanning electron microscope (SEM), a particle size distribution analyzer, or the like. Examples of the form of particles include fine powder, powder, particulates, granules, scales, and polyhedrons. Particles having such an average particle size can be produced by a method which includes grinding particles with, for example, a ball mill, dispersing the resulting coarse particles in a dispersant to give a predetermined particle size, and then dry-hardening the particles; a method which includes sieving the coarse particles to classify the particle sizes; a method which includes optimizing the conditions for producing particles, thereby producing (nano) particles having a predetermined particle size; and the like methods. For a group of many particles having diverse particle sizes, a typical particle size in this group of particles is defined as the average particle size of the group. The particle size is the length of particles measured in conformity with a general rule. For example, (i) in the case of microscopy, two or more lengths of one particle, such as the major axis diameter, the minor axis diameter, and the unidirectional particle diameter, are measured and the average value thereof is defined as the particle size. Preferably, at least 100 particles are measured. (ii) In the case of image analysis, light-shielding, or Coulter principle, the directly measured value (e.g. projected area, volume) as the size of a particle is converted into a systematic shape (e.g. circle, sphere, cube) of the particle based on a geometric formula, and the diameter of the systematic shape is defined as the particle size (equivalent size). (iii) In the case of sedimentation or laser diffraction scattering, the measured value is calculated into a particle size (effective size) based on the physical law (e.g. Mie theory) deduced by supposition of a specific particle shape and specific physical conditions. (iv) In the case of dynamic light scattering, the rate of diffusion (diffusion coefficient) of particles in a liquid owing to Brownian motion is measured to calculate the particle size.
[0065] Process 3 for forming a cathode is preferably implemented as follows.
[0066] First, the cathode mix is optionally combined with water and/or an organic solvent, and the catalyst for an electrode, a later-described conductive auxiliary agent, and/or the organic compound, and kneaded into a paste. Next, the obtained paste mixture is applied to a current collector such as a metal foil (e.g. an aluminum foil) or a metal mesh (e.g. an aluminum mesh, a nickel mesh) in such a manner to form a coat with a thickness as uniform as possible. After coat formation, the coat is preferably dried at 0° C. to 250° C. The drying temperature is more preferably 15° C. to 200° C. The drying may be performed in vacuo. After drying, the coat may be pressed at a pressure of 0.0001 to 20 t using a roll press or the like. The pressing pressure is more preferably 0.001 to 15 t, still more preferably not less than 0.01 t, and particularly preferably not less than 0.1 t.
[0067] The thickness of the cathode is preferably, for example, 1 nm to 2000 μm, more preferably 10 nm to 1500 μm, and still more preferably 100 nm to 1000 μm.
[0068] In Processes 1 to 3, a mixer, blender, kneader, bead mill, ball mill, mechanical mill, or the like can be used to mix or knead materials. Upon mixing, water or an organic solvent such as methanol, ethanol, propanol, isopropanol, tetrahydrofuran, or N-methylpyrrolidone may be added. In order to prepare a mixture of particles with desired particle sizes, an operation such as the above-mentioned sieving method may be performed before and/or after mixing or kneading.
[0069] Next, the active material layer of the anode of the cell of the present invention contains an anode active material containing at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon.
[0070] Examples of the alkali metal include Li, Na, K, Rb, Cs, and Fr. In terms of theoretical capacity and element strategy, Li and Na are preferable, and Li is more preferable.
[0071] Examples of the carbon include graphite, amorphous carbon, carbon nanofoam, activated carbon, graphene, nanographene, graphene nanoribbon, fullerenes, carbon black, fibrous carbon, carbon nanotube, carbon nanohorn, Ketjen black, acetylene black, carbon fibers, and vapor grown carbon fibers. Preferred among these are graphite, graphene, fibrous carbon, carbon nanotube, and acetylene black. More preferred are graphite, graphene, fibrous carbon, carbon nanotube, acetylene black, carbon fibers, and vapor grown carbon fibers.
[0072] The anode active material used in the cell of the present invention may further contain other compounds, as long as it contains at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon.
[0073] The total amount of the anode active material containing at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon is preferably 1.0% by mass or more relative to the mass (100% by mass) of the active material of the anode in terms of theoretical capacity. The amount is more preferably 2.0 to 100% by mass, still more preferably 30 to 100% by mass, and particularly preferably 90% by mass or more.
[0074] In the cell of the present invention, the active material layer of the anode may be made solely of the anode active material, or may be made of an anode mix containing the anode active material, a conductive auxiliary agent, and an organic compound. Typically, the anode includes the active material layer and a current collector, such as a metal foil (e.g. aluminum foil) or a metal mesh (e.g. aluminum mesh, nickel mesh), which is bound to the active material layer of the anode.
[0075] The conductive auxiliary agent and the organic compound are described later.
[0076] The electrolyte in the cell of the present invention is not particularly limited, but preferably includes an alkali metal ion in a dissolved state in a medium. Namely, the cell of the present invention preferably includes an electrolyte solution containing an alkali metal ion dissolved in a medium.
[0077] Examples of the electrolyte include LiPF 6 , LiBF 4 , LiClO 4 , LiN(SO 2 F) 2 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , Li(BC 4 O 8 ), LiF, LiB(CN) 4 , NaPF 6 , NaBF 4 , NaClO 4 , NaN(SO 2 F) 2 , NaN(SO 2 CF 3 ) 2r NaN(SO 2 C 2 F 5 ) 2 , Na(BC 4 O 8 ), NaF, NaB(CN) 4 , potassium hydroxide, sodium hydroxide, lithium carbonate, lithium hydroxide, potassium fluoride, and potassium borate. Preferred are LiPF 6 , LiBF 4 , LiClO 4 , LiN(SO 2 F) 2 , LiN(SO 2 CF 3 ) 2r LiN(SO 2 C 2 F 5 ) 2 , Li(BC 4 O 8 ), LiF, and LiB(CN) 4 .
[0078] The electrolyte solution may be any of common electrolyte solutions for cells, and thus is not particularly limited. Examples of organic solvent-based electrolyte solutions include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, diethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, dimethoxymethane, diethoxymethane, tetrahydrofuran, 2-methyltetrahydrofuran, acetonitrile, benzonitrile, dimethyl sulfoxide, ethylene glycol, ethylene glycol dialkyl ethers, diethylene glycol, diethylene glycol dialkyl ethers, triethylene glycol, triethylene glycol dialkyl ethers, polyethylene glycol, polyethylene glycol dialkyl ethers, polyethylene glycol monoalkyl ether, sulfolane, fluorocarbonates, fluoroethers, ionic liquids, gel compound-containing electrolyte solutions, and polymer-containing electrolyte solutions. Examples of aqueous electrolyte solutions include alkaline aqueous solutions such as aqueous solutions of potassium hydroxide, sodium hydroxide, or lithium hydroxide; and acidic aqueous solutions such as sulfuric acid aqueous solutions. Only one kind of electrolyte solution may be used, or two or more kinds of electrolyte solutions may be used in combination. In the case of using two or more kinds, the solutions may be mixed, or may be separated from each other with a partition.
[0079] The electrolyte concentration in the electrolyte solution is preferably 0.01 to 15 mol/L. The use of an electrolyte solution having a concentration within such a range ensures good cell performance. The concentration is more preferably 0.1 to 12 mol/L.
[0080] The electrolyte solution may contain additives. Examples of additives include materials that can form a protective coat on the cathode or the anode, and materials that, in the case where propylenecarbonate is used as an electrolyte solution, prevent insertion of propylenecarbonate into graphite. Specifically, mention may be made of vinylene carbonate, fluoroethylene carbonate, chloroethylene carbonate, bromoethylene carbonate, ethylene sulfite, propylene sulfite, crown ethers, boron-containing anion receptors, and aluminum-containing anion receptors. These additives may be used alone or in combination.
[0081] The following demonstrates a conductive auxiliary agent, an organic compound, and a separator that can be used for the production of the cell of the present invention.
[0082] The conductive auxiliary agent is preferably a substance having a conductivity within the range of those of electrical materials. Specifically, the conductive auxiliary agent preferably contains a metal, conductive ceramics, or a carbon material. Examples of the metal include nickel powder, aluminum powder, zinc powder, gold powder, and mesoporous gold. Examples of the carbon material (conductive carbon) include graphite, amorphous carbon, carbon nanofoam, activated carbon, graphene, nanographene, graphene nanoribbon, fullerene, carbon black, fibrous carbon, carbon nanotube, carbon nanohorn, Ketjen black, acetylene black, carbon fibers, and vapor grown carbon fiber. Preferred among these are graphene, fibrous carbon, carbon nanotube, acetylene black, carbon fibers, and vapor grown carbon fiber. The conductive auxiliary agent is more preferably graphene, fibrous carbon, carbon nanotube, acetylene black, zinc metal, gold powder, and mesoporous gold.
[0083] The conductive auxiliary agent acts to improve the conductivity of the electrode (s). Any one, or two or more kinds thereof may be used. The conductivity may be improved by coating the alkali metal compound with carbon. The conductive auxiliary agent may have catalytic activity to reduce the overpotential of the reaction at the cathode represented by the reaction formula (II).
[0084] The amount of the conductive auxiliary agent is preferably 0.001 to 90% by mass relative to the mass (100% by mass) of the active material layer of the cathode (or the anode). When the amount of the conductive auxiliary agent is within this range, the cathode (or the anode) exhibits better cell performance. The amount is more preferably 0.01 to 70% by mass, still more preferably 0.05 to 55% by mass, and particularly preferably 0.05 to 50% by mass.
[0085] As examples of the organic compound, salts of organic compounds can be mentioned besides organic compounds. These may be used alone or in combination. Specific examples include poly(meth)acrylic acid-containing polymers, poly(meth)acrylic acid salt-containing polymers, polyacrylonitrile-containing polymers, polyacrylamide-containing polymers, polyvinyl chloride-containing polymers, polyvinyl alcohol-containing polymers, polyethylene oxide-containing polymers, polypropylene oxide-containing polymers, polybutene oxide-containing polymers, polyethylene-containing polymers, polypropylene-containing polymers, polybutene-containing polymers, polyhexene-containing polymers, polyoctene-containing polymers, polybutadiene-containing polymers, polyisoprene-containing polymers, analgen, benzene, trihydroxybenzene, toluene, piperonyl aldehyde, Carbowax, carbazole, cellulose, cellulose acetate, hydroxyalkyl celluloses, carboxymethyl cellulose, dextrin, polyacetylene-containing polymers, polyethyleneimine-containing polymers, polyamide-containing polymers, polystyrene-containing polymers, polytetrafluoroethylene-containing polymers, polyvinylidene fluoride-containing polymers, polypentafluoroethylene-containing polymers, polymaleic acid (anhydride)-containing polymers, polymaleate-containing polymers, polyitaconic acid (anhydride)-containing polymers, polyitaconate-containing polymers, ion exchange polymers for cation or anion-exchange membranes or the like, cyclized polymers, sulfonic acid salts, sulfonic acid salt-containing polymers, quaternary ammonium salts, quaternary ammonium salt-containing polymers, quaternary phosphonium salts, and polymeric quaternary phosphonium salt/ammonium.
[0086] In the case where the organic compound or organic compound salt is a polymer, the polymer can be prepared by radical polymerization, radical (alternating) copolymerization, anionic polymerization, anionic (alternating) copolymerization, cationic (alternating) polymerization, cationic (alternating) copolymerization, or electrolytic polymerization of monomer(s) to be incorporated into the polymer as units.
[0087] The organic compound or organic compound salt can function as a binder for binding particles or particles and the current collector or as a dispersant for effectively dispersing particles.
[0088] The organic compound or organic compound salt is preferably a poly(meth)acrylic acid salt-containing polymer, polyvinyl alcohol-containing polymer, polyethylene oxide-containing polymer, polypropylene oxide-containing polymer, polybutene oxide-containing polymer, cellulose, cellulose acetate, hydroxyalkyl cellulose, carboxymethyl cellulose, polytetrafluoroethylene-containing polymer, polyvinylidene fluoride-containing polymer, polypentafluoroethylene-containing polymer, polymaleate-containing polymer, polyitaconate-containing polymer, ion exchange membrane polymer, sulfonic acid salt-containing polymer, quaternary ammonium salt-containing polymer, or quaternary phosphonium salt polymer.
[0089] The amount of the organic compound or organic compound salt, more preferably the amount of the polymer, is preferably 0.01 to 50% by mass relative to the mass (100% by mass) of the active material layer of the cathode (or the anode). When the amount of the organic compound or organic compound salt, more preferably the amount of the polymer, is in the range, the cathode (or the anode) exhibits much better cell performance. The amount is more preferably 0.01 to 45% by mass, and still more preferably 0.1 to 40% by mass.
[0090] In the case where the cathode mix or the anode mix contains additional component(s) other than the electrode active material, catalyst for an electrode, conductive auxiliary agent, and organic compound, the amount of the additional components is preferably 0.01 to 10% by mass relative to the mass (100% by mass) of the active material layer of the cathode (or the anode). The amount is more preferably 0.05 to 7% by mass, and still more preferably 0.1 to 5% by mass.
[0091] The separator is a member that separates the cathode and the anode, holds the electrolyte solution to ensure ion conduction between the cathode and the anode. The separator is not particularly limited. Examples thereof include high-molecular-weight materials with micropores such as polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, cellulose, cellulose acetate, hydroxyalkyl celluloses, carboxymethyl cellulose, polyvinyl alcohol, cellophane, polystyrene, polyacrylonitrile, polyacrylamide, polyvinyl chloride, polyamide, vinylon, and poly(meth)acrylic acid; gel compounds; ion exchange membrane polymers; cyclized polymers; poly(meth)acrylic acid (salt)-containing polymers; sulfonic acid (salt)-containing polymers; quaternary ammonium salt-containing polymers; quaternary phosphonium salt-containing polymers; and solid electrolytes such as ion conductive polymers and ion conductive glass.
[0092] The cell of the present invention includes the cathode, the anode, and the electrolyte, and these are hermetically sealed in the cell.
[0093] The cell of the present invention may be in any form without limitation, and may be in the form of a primary cell or a secondary cell (rechargeable cell) that can be discharged and recharged, or in a form including a mechanical charging system or a form with a third electrode in addition to the cathode and the anode. The cell may be assembled in the charged state or in the discharged state.
Advantageous Effects of Invention
[0094] The cell of the present invention has the above-mentioned structure, and makes use of a novel principle different from those of conventional cells. Specifically, the cell of the present invention has a high theoretical voltage and theoretical capacity, has high cell performance to be able to discharge and recharge multiple times, and has cost and environmentally-friendly advantages.
BRIEF DESCRIPTION OF DRAWINGS
[0095] FIG. 1 is a graph showing the results of cyclic voltammetry using a cathode prepared in Preparation 1.
[0096] FIG. 2 is a graph showing the results of cyclic voltammetry using a cathode prepared in Preparation 2.
[0097] FIG. 3 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 7.
[0098] FIG. 4 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 8.
[0099] FIG. 5 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 9.
[0100] FIG. 6 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 10.
[0101] FIG. 7 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 11.
[0102] FIG. 8 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 12.
[0103] FIG. 9 is a graph showing the results of a charge/discharge test in Example 3.
[0104] FIG. 10 is a graph showing the results of a charge/discharge test in Example 4.
[0105] FIG. 11 is a graph showing the results of a charge/discharge test in Example 5.
[0106] FIG. 12 is a graph showing the results of a charge/discharge test in Example 6.
[0107] FIG. 13 is a graph showing the results of a charge/discharge test in Example 7.
[0108] FIG. 14 is a graph showing the results of a charge/discharge test in Example 8.
[0109] FIG. 15 is a graph showing the results of analysis of gas generated during charge in Example 9.
[0110] FIG. 16 is a graph showing the result of XRD measurement of a charged cathode in Example 10.
[0111] FIG. 17 is a graph showing the results of a charge/discharge test in Example 12.
[0112] FIG. 18 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 13.
[0113] FIG. 19 is a graph showing the results of a charge/discharge test in Example 13.
[0114] FIG. 20 is a graph showing the result of XRD measurement before and after charging in Example 14.
[0115] FIG. 21 is a graph showing the results of quantification of a peroxide in Example 15.
[0116] FIG. 22 is a graph showing the results of quantification of a peroxide in Example 15.
[0117] FIG. 23 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 14.
[0118] FIG. 24 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 15.
[0119] FIG. 25 is a graph showing the results of a charge/discharge test in Example 16.
[0120] FIG. 26 is a graph showing the results of a charge/discharge test in Example 17.
[0121] FIG. 27 is a graph showing the results of a charge/discharge test in Example 18.
[0122] FIG. 28 is a graph showing the results of a charge/discharge test in Example 19.
[0123] FIG. 29 is a graph showing the results of a charge/discharge test in Example 20.
[0124] FIG. 30 is a graph showing the results of a charge test in Example 21.
[0125] FIG. 31 is a graph showing the results of a charge test in Example 22.
[0126] FIG. 32 is a graph showing the results of a charge test in Example 23.
[0127] FIG. 33 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 16.
[0128] FIG. 34 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 17.
[0129] FIG. 35 is a graph showing the results of a charge/discharge test in Example 24.
[0130] FIG. 36 is a graph showing the results of a charge/discharge test in Example 25.
[0131] FIG. 37 is a graph showing the results of a charge/discharge test in Example 26.
[0132] FIG. 38 is a graph showing the results of a charge/discharge test in Example 27.
[0133] FIG. 39 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 18.
[0134] FIG. 40 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 19.
[0135] FIG. 41 is a graph showing the results of a charge/discharge test in Example 28.
[0136] FIG. 42 is a graph showing the results of a charge/discharge test in Example 29.
[0137] FIG. 43 is a graph showing the results of a charge/discharge test in Example 30.
[0138] FIG. 44 is a graph showing the results of a charge/discharge test in Example 31.
[0139] FIG. 45 is a graph showing the results of XRD measurement before and after charging and discharging in Example 32.
[0140] FIG. 46 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 20.
[0141] FIG. 47 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 21.
[0142] FIG. 48 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 22.
[0143] FIG. 49 is a graph showing the results of XRD measurement of solid powder prepared in Preparation 23.
[0144] FIG. 50 is a graph showing the results of a charge/discharge test in Example 34.
[0145] FIG. 51 is a graph showing the results of a charge/discharge test in Example 35.
[0146] FIG. 52 is a graph showing the results of a charge/discharge test in Example 36.
[0147] FIG. 53 is a graph showing the results of a charge/discharge test in Example 37.
DESCRIPTION OF EMBODIMENTS
[0148] The following examples are offered to demonstrate the present invention in more detail, but should not be construed as limiting the present invention. All parts are by mass unless otherwise specified, and all percentages are by mass unless otherwise specified.
Preparation 1
[0149] An amount of 28 mg of lithium oxide (Li 2 O, produced by Strem Chemicals Inc.) as a cathode active material, 80 mg of a catalyst for an electrode (60% Ag/C, produced by Alfa Aesar), and 15 mg of polytetrafluoroethylene (PTFE) were kneaded into a cathode mix. A 14 mg portion of the cathode mix was pressed onto 80 mg of a nickel mesh, whereby a cathode was prepared.
Preparation 2
[0150] An amount of 85 mg of a catalyst for an electrode (60% Ag/C, produced by Alfa Aesar) and 15 mg of PTFE were kneaded into a cathode mix. A 14 mg portion of the cathode mix was pressed onto 80 mg of a nickel mesh, whereby a cathode was prepared.
Example 1
[0151] A three-electrode cell was prepared in which the working electrode was the cathode prepared in Preparation 1, the counter electrode and the reference electrode were lithium metal, and the electrolyte solution was a 1 M LiClO 4 /propylenecarbonate (PC) electrolyte solution. The three-electrode cell was measured by cyclic voltammetry (CV) in a glove box. In the measurement, the electrode potential was changed from the open circuit voltage (OCV) 3.38 V→4 V→1.2 V→OCV 3.38 V at a scan rate of 0.2 mV/s.
[0152] FIG. 1 shows the results. In FIG. 1 , the horizontal axis represents the potential, and the vertical axis represents the current.
[0153] The results shown in FIG. 1 demonstrate that the use of the cathode prepared in Preparation 1 resulted in oxidation peaks at approximately 3.05 V and approximately 3.7 V, and a reduction peak at approximately 2.25 V. Considering that the theoretical potential of the reaction 2Li 2 O→Li 2 O 2 +2Li + +2e − is 2.87 V, the oxidation and reduction peaks observed in this experiment were concluded as oxidation reduction peaks corresponding to the forward and reverse reactions of the formula.
Comparative Example 1
[0154] Following the same procedure as in Example 1 and using the cathode prepared in Preparation 2 as a working electrode, cyclic voltammetry (CV) was performed.
[0155] FIG. 2 shows the results. The results shown in FIG. 2 demonstrate that the use of the cathode prepared in Preparation 2 which is free from Li 2 O resulted in no oxidation and reduction peak.
Preparation 3
[0156] An amount of 44 mg of lithium oxide (Li 2 O, produced by Strem Chemicals Inc.) as a cathode active material, 84 mg of artificial graphite KS6L (produced by TIMCAL Graphite & Carbon's), and 7 mg of polytetrafluoroethylene (PTFE) were kneaded into a cathode mix. A 6 mg portion of the cathode mix was pressed onto 80 mg of a nickel mesh, whereby a cathode was prepared.
Preparation 4
[0157] Following the same procedure as in Preparation 3 and using lithium peroxide (Li 2 O 2 , produced by Alfa Aesar) as a cathode active material instead of lithium oxide, a cathode mix was prepared. A 6 mg portion of the cathode mix was pressed onto 80 mg of a nickel mesh, whereby a cathode was prepared.
Preparation 5
[0158] Following the same procedure as in Preparation 3 and using sodium oxide (Na 2 O, produced by Alfa Aesar) as a cathode active material instead of lithium oxide, a cathode mix was prepared. A 6 mg portion of the cathode mix was pressed onto 80 mg of a nickel mesh, whereby a cathode was prepared.
Preparation 6
[0159] Following the same procedure as in Preparation 3 and using sodium peroxide (Na 2 O 2 , produced by Wako Pure Chemical Industries, Ltd.) as a cathode active material instead of lithium oxide, a cathode mix was prepared. A 6 mg portion of the cathode mix was pressed onto 80 mg of a nickel mesh, whereby a cathode was prepared.
Example 2
[0160] Three-electrode cells were prepared in which the cathodes prepared in Preparations 3 to 6 were individually used as a working electrode, the counter electrode and the reference electrode were lithium metal, and the electrolyte solution was a propylenecarbonate (PC) electrolyte solution. The three-electrode cells were subjected to a charge/discharge test in a glove box. Charging and discharging were performed under the following conditions: cut-off potential: 1.4 to 4.2 V; and current load: 0.134 A per mol of the active material. In the experiments using the cathodes prepared in Preparations 3 and 5, the cycle was started with a charge phase, and in the experiments using the cathodes prepared in Preparations 4 and 6, the cycle was started with a discharge phase. Table 1 shows the results.
[0000]
TABLE 1
(mAh/g)
Preparation 3
Preparation 4
Preparation 5
Preparation 6
Discharge
79
150
146
115
capacity in
first cycle
Discharge
66
41
13
16
capacity in
third cycle
[0161] As seen in Table 1, in all the cases using the cathodes, the cells could be discharged and recharged multiple times. It was also revealed that the cathodes according to the present invention can function regardless of whether they are in a discharged state or a charged state when assembled into a cell.
Preparation 7 (Process for Preparing Li 2 O/Fe 2 O 3 Cathode)
[0162] An amount of 1.99 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 2.09 g of α-iron oxide (produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ were operated at a rate of rotation of 600 rpm for 60 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 3 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to be a mixture of Li 2 O and LiFeO 2 . A 172 mg portion of the solid powder, 200 mg of acetylene black as a conductive auxiliary agent, and 28 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 8 (Process for Preparing Li 2 O/Co 3 O 4 Cathode)
[0163] An amount of 1.43 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 1.54 g of cobalt oxide (Co 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 60 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 4 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to be a mixture of Li 2 O and Co 3 O 4 . A 126 mg portion of the solid powder, 142 mg of acetylene black as a conductive auxiliary agent, and 20 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 9 (Process for Preparing Li 2 O/NiO Cathode)
[0164] An amount of 2.75 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 2.74 g of nickel oxide (NiO, produced by Kanto Chemical Co., Inc.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 60 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 5 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to be a mixture of Li 2 O and NiO. A 73 mg portion of the solid powder, 89 mg of acetylene black as a conductive auxiliary agent, and 14 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 10 (Process for Preparing Li 2 O/LiCoO 2 Cathode)
[0165] An amount of 2.32 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 3.05 g of lithium cobalt oxide (produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 60 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 6 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to be a mixture of Li 2 O and LiCoO 2 . A 61 mg portion of the solid powder, 77 mg of acetylene black as a conductive auxiliary agent, and 10 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 11 (Process for Preparing Li 2 O/MnO 2 Cathode)
[0166] An amount of 1.90 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 2.22 g of manganese dioxide (produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ were operated at a rate of rotation of 600 rpm for 60 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 7 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to be a mixture of Li 2 O and MnO 2 . A 113 mg portion of the solid powder, 134 mg of acetylene black as a conductive auxiliary agent, and 21 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 12 (Process for Preparing Li 2 O/SrCoO 2.5 Cathode)
[0167] An amount of 4.43 g of strontium carbonate (produced by Wako Pure Chemical Industries, Ltd.) and 2.41 g of cobalt oxide (Co 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) were mixed in an agate mortar, and fired under an air atmosphere at 900° C. for 12 hours, whereby an oxygen-deficient perovskite compound SrCoO 2.5 was obtained.
[0168] An amount of 0.98 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 0.48 g of the SrCoO 2.5 prepared above as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ were operated at a rate of rotation of 600 rpm for 60 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 8 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to be a mixture of Li 2 O and amorphous SrCoO 2.5 . A 35 mg portion of the solid powder, 46 mg of acetylene black as a conductive auxiliary agent, and 7 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Example 3
Charge/Discharge Test
[0169] A charge/discharge test was performed using a three-electrode cell having a conventional structure. The working electrode was the Li 2 O/Fe 2 O 3 cathode mix electrode prepared in Preparation 7, the counter and reference electrodes were lithium metal, and the electrolyte solution was a 1 M LiTFSI DME electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ], DME: 1,2-dimethoxyethane). After charging at a current density of 4.5 mA/g of the cathode active material, discharging was performed at a similar current density. FIG. 9 shows the results of the charge/discharge test. As seen in FIG. 9 , the use of lithium oxide as a cathode active material allows for repetition of charging and discharging.
Example 4
Charge/Discharge Test
[0170] The charge/discharge test was performed under the same conditions as in Example 3 using the Li 2 O/Co 3 O 4 cathode mix electrode prepared in Preparation 8 as a working electrode. FIG. 10 shows the results of the measurement. As seen in FIG. 10 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 5
Charge/Discharge Test
[0171] The charge/discharge test was performed under the same conditions as in Example 3 using the Li 2 O/NiO cathode mix electrode prepared in Preparation 9 as a working electrode. FIG. 11 shows the results of the measurement. As seen in FIG. 11 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 6
Charge/Discharge Test
[0172] The charge/discharge test was performed under the same conditions as in Example 3 using the Li 2 O/LiCoO 2 cathode mix electrode prepared in Preparation 10 as a working electrode. FIG. 12 shows the results of the measurement. As seen in FIG. 12 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 7
Charge/Discharge Test
[0173] The charge/discharge test was performed under the same conditions as in Example 3 using the Li 2 O/MnO 2 cathode mix electrode prepared in Preparation 11 as a working electrode. FIG. 13 shows the results of the measurement. As seen in FIG. 13 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 8
Charge/Discharge Test
[0174] The charge/discharge test was performed under the same conditions as in Example 3 using the Li 2 O/SrCoO 2.5 cathode mix electrode prepared in Preparation 12 as a working electrode. FIG. 14 shows the results of the measurement. As seen in FIG. 14 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 9
Analysis of Gas Generated During Charge
[0175] The charge test was performed under the same conditions as in Example 3, and components in the gas phase in the cell were identified and quantified using a quadrupole mass spectrometer. FIG. 15 shows the results of the measurement. As seen in FIG. 15 , no noticeable gas generation was observed in the range of the capacity of oxidation up to 600 mAh/g. This demonstrates that Li 2 O was converted into Li 2 O 2 without generating oxygen. The arrows in FIG. 15 indicate which scale of the right or left vertical axis to use for each line in the graph.
Example 10
XRD Analysis of Charged Cathode
[0176] The charge test was performed under the same conditions as in Example 5. After charging to a cut-off voltage of 3.3 V, the cathode was washed with a DME (1,2-dimethoxyethane) solvent and then dried. The charged cathode was then placed on a hermetically sealed sample stage purged with argon, and subjected to XRD measurement. FIG. 16 shows the results. A Li 2 O signal diminishes around 33.5° with changing capacity of oxidation, and signals of Li 2 O 2 were observed at 34.5° and 39.8°. This demonstrates that Li 2 O was converted into Li 2 O 2 during charge.
Example 11
Quantification of Li 2 O 2 in Charged Cathode
[0177] The charge test was performed under the same conditions as in Example 4. A cathode was prepared by pressing 8.24 mg of the cathode mix onto 60 mg of an aluminum mesh. After charging to a cut-off voltage of 3.3 V, the cathode was washed with a DME (1,2-dimethoxyethane) solvent and then dried. The oxidized cathode prepared in a glove box under an argon atmosphere and 1 mg of manganese dioxide were dispersed in 1 ml of deoxidized water. Li 2 O 2 , which was converted from Li 2 O during charge, dissolved in water to form H 2 O 2 , and then the reaction (H 2 O 2 →H 2 O+0.5O 2 ) occurred in the presence of manganese dioxide as a catalyst, thereby to generate oxygen gas. The oxygen gas was identified and quantified using a quadrupole mass spectrometer. The results confirm generation of 2.3 μmol of oxygen. This demonstrates that Li 2 O 2 was generated as a result of the charge reaction from Li 2 O.
Example 12
Charge/Discharge Test Using Two-Electrode Cell
[0178] The charge/discharge test was performed using a commercially available two-electrode cell (HS cell, produced by Hohsen Corp.). The working electrode was the Li 2 O/Fe 2 O 3 cathode mix electrode prepared in Preparation 7, the counter electrode was lithium metal, and the electrolyte solution was a 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl) imide [LiN(SO 2 CF 3 ) 2 ]). After charging at a current density of 4.5 mA/g of the cathode active material, discharging was performed at a similar current density. FIG. 17 shows the results of the charge/discharge test. As seen in FIG. 17 , the use of lithium oxide as a cathode active material allows for charging and discharging.
[0179] LiCoO 2 used in Preparation 10 and Example 6 is a common compound widely known as a cathode active material. Although the charge/discharge potential of LiCoO 2 is 3.8 V (vs. Li metal) the charge potential in the charge/discharge experiment in Example 6 (shown in FIG. 12 ) was approximately 3.2 V (vs. Li metal). From this fact, it is unlikely that LiCoO 2 itself functioned as an active material in charging and discharging, and LiCoO 2 is presumed to have functioned as a catalyst for an electrode in Example 6. Likewise, LiFeO 2 used in Preparation 7 and Example 3 and SrCoO 2.5 used in Preparation 12 and Example 8 are presumed to have functioned as a catalyst for an electrode in Example 8. Additionally, each single oxide (Co 3 O 4 , NiO, MnO 2 ) is also presumed to have functioned as a catalyst for an electrode when used alone in the absence of Li 2 O because flat ranges indicating charging and discharging were not observed unlike the examples.
Preparation 13 (Process for Preparing Li 2 O/Fe 2 O 3 /Co 3 O 4 Cathode)
[0180] An amount of 2.62 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material, 1.38 g of α-iron oxide (produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode, and 1.36 g of cobalt oxide (Co 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 60 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 18 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O and LiFeO 2 . An 81 mg portion of the solid powder, 100 mg of acetylene black as a conductive auxiliary agent, and 15 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Example 13
Charge/Discharge Test Using Two-Electrode Cell
[0181] The charge/discharge test was performed using a commercially available two-electrode cell (HS cell, produced by Hohsen Corp.). The working electrode was the Li 2 O/Fe 2 O 3 /Co 3 O 4 cathode mix electrode prepared in Preparation 13, the counter electrode was lithium metal, and the electrolyte solution was a 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). After charging at a current density of 4.5 mA/g of the cathode active material, discharging was performed at a similar current density. FIG. 19 shows the results of the charge/discharge test. As seen in FIG. 19 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 14
XRD Analysis of Charged Cathode
[0182] The charge test was performed under the same conditions as in Example 13. After charging to a cut-off voltage of 3.3V, the cathode was washed with an acetonitrile solvent and then dried. The charged cathode was then placed on a hermetically sealed sample stage purged with argon, and subjected to XRD measurement. FIG. 20 shows the results. A Li 2 O signal diminishes around 33.5° with changing capacity of oxidation. This indicates that Li 2 O was converted into Li 2 O 2 during charge.
Example 15
Quantification of Li 2 O 2 in Cathode after Charging and Discharging
[0183] The charge/discharge test was performed under the same conditions as in Example 13. Quantification of lithium peroxide in the cathode was performed in the same manner as in Example 11 at different depths of charge/discharge. FIG. 21 shows the results of the detected amount of Li 2 O 2 plotted against the charge capacity in the first charge phase. The figure also includes a solid line representing the theoretical amount of Li 2 O 2 estimated against the charge capacity based on the reaction formula (II). As seen in FIG. 21 , it was confirmed that, the charge reaction generated Li 2 O 2 as shown in the reaction formula (II) at a theoretical efficiency based on the charge capacity of approximately 80%. FIG. 22 shows detected amounts of Li 2 O 2 plotted against the discharge capacity in the first discharge phase after the first charge phase. The figure also includes a solid line representing the theoretical amount of Li 2 O 2 estimated against the discharge capacity based on the reaction formula (II). As seen in FIG. 22 , it was confirmed that Li 2 O 2 was consumed as shown in the reaction formula (II) at a theoretical efficiency based on the discharge capacity of almost 100%.
Preparation 14 (Process for Preparing Li 2 O/Fe 2 O 3 /Co 3 O 4 Cathode)
[0184] An amount of 2.46 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd) as a cathode active material, 0.65 g of α-iron oxide (produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode, and 0.67 g of cobalt oxide (CO 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 120 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 23 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. A 79 mg portion of the solid powder, 83 mg of acetylene black as a conductive auxiliary agent, and 12 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 15 (Process for Preparing Li 2 O/Fe 2 O 3 /Co 3 O 4 Cathode)
[0185] An amount of 2.47 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material, 0.33 g of α-iron oxide (produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode, and 0.33 g of cobalt oxide (Co 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 120 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 24 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. A 66 mg portion of the solid powder, 70 mg of acetylene black as a conductive auxiliary agent, and 6 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Example 16
Charge/Discharge Test Using Two-Electrode Cell
[0186] The charge/discharge test was performed under the same conditions as in Example 13 using the Li 2 O/Fe 2 O 3 /Co 3 O 4 cathode mix electrode prepared in Preparation 14 as a working electrode. FIG. 25 shows the results of the charge/discharge test. As seen in FIG. 25 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 17
Charge/Discharge Test Using Two-Electrode Cell
[0187] The charge/discharge test was performed under the same conditions as in Example 13 using the Li 2 O/Fe 2 O 3 /Co 3 O 4 cathode mix electrode prepared in Preparation 15 as a working electrode. FIG. 26 shows the results of the charge/discharge test. As seen in FIG. 26 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 18
Charge/Discharge Test Using Two-Electrode Cell
[0188] The charge/discharge test was performed under the same conditions as in Example 13, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 27 shows the results of the charge/discharge test. As seen in FIG. 27 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 19
Charge/Discharge Test Using Two-Electrode Cell
[0189] The charge/discharge test was performed under the same conditions as in Example 16, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 28 shows the results of the charge/discharge test. As seen in FIG. 28 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 20
Charge/Discharge Test Using Two-Electrode Cell
[0190] The charge/discharge test was performed under the same conditions as in Example 17, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 29 shows the results of the charge/discharge test. As seen in FIG. 29 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 21
Charge Test Using Two-Electrode Cell
[0191] The charge test was performed using a commercially available two-electrode cell (HS cell, produced by Hohsen Corp.). The working electrode was the Li 2 O/Fe 2 O 3 /Co 3 O 4 cathode mix electrode prepared in Preparation 13, the counter electrode was lithium metal, and the electrolyte solution was a 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). Charging was performed at a current density of 4.5 mA/g of the cathode active material. FIG. 30 shows the results of the charge test. In FIG. 30 , a fast increase of the potential is observed around the theoretical charge capacity (894 mAh/g) of the charge reaction at the cathode (2Li 2 O→Li 2 O 2 +2Li + +2e − ). This demonstrates that the charge reaction at the cathode proceeded at remarkably high efficiency.
Example 22
Charge Test Using Two-Electrode Cell
[0192] The charge test was performed using a commercially available two-electrode cell (HS cell, produced by Hohsen Corp.). The working electrode was the Li 2 O/Fe 2 O 2 /Co 3 O 4 cathode mix electrode prepared in Preparation 14, the counter electrode was lithium metal, and the electrolyte solution was a 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). Charging was performed at a current density of 4.5 mA/g of the cathode active material. FIG. 31 shows the results of the charge test. In FIG. 31 , a fast increase of the potential is observed around the theoretical charge capacity (894 mAh/g) of the charge reaction at the cathode (2Li 2 O→Li 2 O 2 +2Li + +2e − ). This demonstrates that the charge reaction at the cathode proceeded at remarkably high efficiency.
Example 23
Charge Test Using Two-Electrode Cell
[0193] The charge test was performed using a commercially available two-electrode cell (HS cell, produced by Hohsen Corp.). The working electrode was the Li 2 O/Fe 2 O 3 /Co 3 O 4 cathode mix electrode prepared in Preparation 15, the counter electrode was lithium metal, and the electrolyte solution was a 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). Charging was performed at a current density of 4.5 mA/g of the cathode active material. FIG. 32 shows the results of the charge test. In FIG. 32 , a fast increase of the potential is observed around the theoretical charge capacity (894 mAh/g) of the charge reaction at the cathode (2Li 2 O→Li 2 O 2 +2Li + +2e − ). This demonstrates that the charge reaction at the cathode proceeded at remarkably high efficiency.
Preparation 16 (Process for Preparing Li 2 O/Co 3 O 4 Cathode)
[0194] An amount of 2.09 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 2.23 g of cobalt oxide (Co 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 33 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O and LiCoO 2 . A 57 mg portion of the solid powder, 69 mg of acetylene black as a conductive auxiliary agent, and 6 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 17 (Process for Preparing Li 2 O/Co 3 O 4 Cathode)
[0195] An amount of 2.19 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 1.16 g of cobalt oxide (CO 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 34 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O and LiCoO 2 . A 67 mg portion of the solid powder, 70 mg of acetylene black as a conductive auxiliary agent, and 6 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Example 24
Charge/Discharge Test Using Two-Electrode Cell
[0196] The charge/discharge test was performed under the same conditions as in Example 13 using the Li 2 O/Co 3 O 4 cathode mix electrode prepared in Preparation 16 as a working electrode. FIG. 35 shows the results of the charge/discharge test. As seen in FIG. 35 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 25
Charge/Discharge Test Using Two-Electrode Cell
[0197] The charge/discharge test was performed under the same conditions as in Example 13 using the Li 2 O/Co 3 O 4 cathode mix electrode prepared in Preparation 17 as a working electrode. FIG. 36 shows the results of the charge/discharge test. As seen in FIG. 36 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 26
Charge/Discharge Test Using Two-Electrode Cell
[0198] The charge/discharge test was performed under the same conditions as in Example 24, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 37 shows the results of the charge/discharge test. As seen in FIG. 37 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 27
Charge/Discharge Test Using Two-Electrode Cell
[0199] The charge/discharge test was performed under the same conditions as in Example 25, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 38 shows the results of the charge/discharge test. As seen in FIG. 38 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Preparation 18 (Process for Preparing Li 2 O/Co 3 O 4 Cathode)
[0200] An amount of 2.43 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 0.66 g of cobalt oxide (Co 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 39 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. A 51 mg portion of the solid powder, 63 mg of acetylene black as a conductive auxiliary agent, and 4 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 19 (Process for Preparing Li 2 O/Co 3 O 4 Cathode)
[0201] An amount of 2.63 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 0.36 g of cobalt oxide (CO 3 O 4 , produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 40 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. A 57 mg portion of the solid powder, 61 mg of acetylene black as a conductive auxiliary agent, and 5 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Example 28
Charge/Discharge Test Using Two-Electrode Cell
[0202] The charge/discharge test was performed under the same conditions as in Example 13 using the Li 2 O/Co 3 O 4 cathode mix electrode prepared in Preparation 18 as a working electrode. FIG. 41 shows the results of the charge/discharge test. As seen in FIG. 41 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 29
Charge/Discharge Test Using Two-Electrode Cell
[0203] The charge/discharge test was performed under the same conditions as in Example 13 using the Li 2 O/Co 3 O 4 cathode mix electrode prepared in Preparation 19 as a working electrode. FIG. 42 shows the results of the charge/discharge test. As seen in FIG. 42 , the use of lithium oxide as a cathode active material allows for charging and discharging.
Example 30
Charge/Discharge Test Using Two-Electrode Cell
[0204] The charge/discharge test was performed under the same conditions as in Example 28, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 43 shows the results of the charge/discharge test. As seen in FIG. 43 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 31
Charge/Discharge Test Using Two-Electrode Cell
[0205] The charge/discharge test was performed under the same conditions as in Example 29, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 44 shows the results of the charge/discharge test. As seen in FIG. 44 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 32
XRD Analysis of Charged Cathode
[0206] The charge test was performed under the same conditions as in Example 27. After charging at 400 mAh/g, the cathode was washed with an acetonitrile solvent and then dried. The charged cathode was placed on a hermetically sealed sample stage purged with argon, and subjected to XRD measurement. FIG. 45 shows the results. A Li 2 O signal diminishes around 33.5° with changing capacity of oxidation. This indicates that Li 2 O was converted into Li 2 O 2 during charge.
Example 33
Quantification of Li 2 O 2 in Cathode after Charging and Discharging
[0207] The charge/discharge test was performed under the same conditions as in Example 27. Quantification of lithium peroxide in the cathode was performed in the same manner as in Example 11 after each charge or discharge phase. The amount of lithium peroxide in the mix after the first charge phase was 4.17 mmol/g of lithium oxide in the mix at the beginning. The amount of lithium peroxide in the mix after the first discharge phase following the first charge phase was 0.17 mmol/g of lithium oxide in the mix at the beginning. Thus, it was confirmed that lithium peroxide was almost completely consumed through discharge. The amount of lithium peroxide after the second charge phase was 3.89 mmol/g. This demonstrates that reversible oxidation into lithium peroxide occurred again during recharge.
Preparation 20 (Process for Preparing Li 2 O/CoO Cathode)
[0208] An amount of 2.30 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 2.31 g of cobalt oxide (CoO, produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 46 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. A 75 mg portion of the solid powder, 85 mg of acetylene black as a conductive auxiliary agent, and 6 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 21 (Process for Preparing Li 2 O/CoO Cathode)
[0209] An amount of 2.30 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 1.15 g of cobalt oxide (CoO, produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 47 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. A 59 mg portion of the solid powder, 66 mg of acetylene black as a conductive auxiliary agent, and 4 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 22 (Process for Preparing Li 2 O/CoO Cathode)
[0210] An amount of 2.95 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd) as a cathode active material and 0.75 g of cobalt oxide (CoO, produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 48 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. An 89 mg portion of the solid powder, 107 mg of acetylene black as a conductive auxiliary agent, and 8 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Preparation 23 (Process for Preparing Li 2 O/CoO Cathode)
[0211] An 3.09 g of lithium oxide (produced by Kojundo Chemical Laboratory Co., Ltd.) as a cathode active material and 0.39 g of cobalt oxide (CoO, produced by Wako Pure Chemical Industries, Ltd.) as a catalyst for an electrode were combined in a planetary ball mill pot, and mixed using a planetary ball mill (under conditions in which 25 zirconia balls (10 mmφ) were operated at a rate of rotation of 600 rpm for 180 hours). The whole procedure was performed in an argon-substituted glove box with a moisture concentration of not higher than 1 ppm. FIG. 49 shows the results of XRD measurement of the resultant solid powder. The solid powder was found to contain Li 2 O. An 87 mg portion of the solid powder, 94 mg of acetylene black as a conductive auxiliary agent, and 7 mg of polytetrafluoroethylene powder as a binder were mixed in an agate mortar, and processed into a clay-like mixture, whereby a cathode mix was prepared. The cathode mix was pressed onto 60 mg of an aluminum mesh, whereby a cathode was prepared.
Example 34
Charge/Discharge Test Using Two-Electrode Cell
[0212] The charge/discharge test was performed under the same conditions as in Example 28, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl) imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 50 shows the results of the charge/discharge test. As seen in FIG. 50 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 35
Charge/Discharge Test Using Two-Electrode Cell
[0213] The charge/discharge test was performed under the same conditions as in Example 29, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl) imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]). FIG. 51 shows the results of the charge/discharge test. As seen in FIG. 51 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 36
Charge/Discharge Test Using Two-Electrode Cell
[0214] The charge/discharge test was performed under the same conditions as in Example 28, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]), and that the current density during the charge and discharge phases was 22.5 mA/g of the active material. FIG. 52 shows the results of the charge/discharge test. As seen in FIG. 52 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
Example 37
Charge/Discharge Test Using Two-Electrode Cell
[0215] The charge/discharge test was performed under the same conditions as in Example 29, except that a 4.2 M LiFSI acetonitrile electrolyte solution (LiFSI: lithium bis(fluorosulfonyl)imide [LiN(SO 2 F) 2 ]) was used as an electrolyte solution instead of the 4.2 M LiTFSI acetonitrile electrolyte solution (LiTFSI: lithium bis(trifluoromethanesulfonyl)imide, [LiN(SO 2 CF 3 ) 2 ]), and that the current density during the charge and discharge phases was 22.5 mA/g of the active material. FIG. 53 shows the results of the charge/discharge test. As seen in FIG. 53 , the use of lithium oxide as a cathode active material under the above conditions also allows for charging and discharging.
[0216] The results of the examples reveal that the cells including a cathode according to the present invention have a high theoretical voltage and theoretical capacity, and can be discharged and recharged multiple times. The examples also suggest that in cells including such a cathode, the same mechanism functions to provide a high theoretical volume and theoretical capacity, and allow repetition of charging and discharging.
[0217] Accordingly, the results of the examples demonstrate that all of the various embodiments of the present invention disclosed herein can be applied in the entire technical range of the present invention, and provide advantageous effects.
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The present invention provides a cell that has a high theoretical voltage and theoretical capacity, and can be discharged and recharged multiple times. The cell includes a cathode, an anode, and an electrolyte, wherein the cathode contains a cathode active material containing an alkali metal compound represented by the formula (1):
A x O y (1)
(wherein A is an alkali metal atom, x is 0.5 to 2.5, and y is 0.5 to 2.5), the anode contains an anode active material containing at least one selected from the group consisting of an alkali metal, tin, titanium, boron, nitrogen, silicon, and carbon, and the cathode, the anode, and the electrolyte are hermetically sealed in the cell.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a system for the wireless distribution of digital multimedia content, and more specifically, to an automated system for selecting, based on broadcast content, digital multimedia programs to be downloaded to a wireless communication device in accordance with any digital rights requirements that may be protecting the content.
2. Description of Prior Art
Modern society has quickly adopted, and become reliant upon, handheld devices for wireless communication. For example, cellular telephones continue to proliferate in the global marketplace due to technological improvements in both the quality of the communication and the functionality of the devices. These wireless communication devices (WCDs) have become commonplace for both personal and business use, allowing users to transmit and receive voice, text and graphical data from a multitude of geographic locations. The communication networks utilized by these devices span different frequencies and cover different broadcast distances, each having strengths desirable for various applications.
Cellular networks facilitate WCD communication over large geographic areas. These network technologies have commonly been divided by generations, starting in the late 1970s to early 1980s with first generation (1G) analog cellular telephones that provided baseline voice communications, to the now emerging 4G streaming digital video content planned for the 2006-2007 timeframe. GSM is an example of a widely employed 2G digital cellular network communicating in the 900 MHZ-1.8 GHZ band in Europe and at 1.9 GHZ in the United States. This network provides voice communication and also supports the transmission of textual data via the Short Messaging Service (SMS). SMS allows a WCD to transmit and receive text messages of up to 160 characters, while providing data transfer to packet networks, ISDN and POTS users at 9.6 Kbps. The Multimedia Messaging Service (MMS), an enhanced messaging system allowing for the transmission of sound, graphics and video files in addition to simple text, has also become available in certain devices. Soon emerging technologies such as Digital Video Broadcasting for Handheld Devices (DVB-H) will make streaming digital video, and other similar content, available via direct broadcast to a WCD. While long-range communication networks like GSM are a well-accepted means for transmitting and receiving data, due to cost, traffic and legislative concerns, these networks may not be appropriate for all data applications.
Short-range wireless networks provide communication solutions that avoid some of the problems seen in large cellular networks. Bluetooth™ is an example of a short-range wireless technology quickly gaining acceptance in the marketplace. A Bluetooth™ enabled WCD transmits and receives data at a rate of 720 Kbps within a range of 10 meters, and may transmit up to 100 meters with additional power boosting. A user does not actively instigate a Bluetooth™ network. Instead, a plurality of devices within operating range of each other will automatically form a network group called a “piconet”. Any device may promote itself to the master of the piconet, allowing it to control data exchanges with up to seven “active” slaves and 255 “parked” slaves. Active slaves exchange data based on the clock timing of the master. Parked slaves monitor a beacon signal in order to stay synchronized with the master, and wait for an active slot to become available. These devices continually switch between various active communication and power saving modes in order to transmit data to other piconet members. In addition to Bluetooth™ other popular short-range wireless networks include WLAN (of which “Wi-Fi” local access points communicating in accordance with the IEEE 802.11 standard, is an example), WUSB, UWB, etc. All of these wireless mediums have features and advantages that make them appropriate for various applications.
More recently, manufacturers have also began to incorporate various resources for providing enhanced functionality in WCDs (e.g., components and software for performing close-proximity wireless information exchanges). Sensors and/or scanners may be used to read visual or electronic information into a device. A transaction may involve a user holding their WCD in proximity to a target, aiming their WCD at an object (e.g., to take a picture) or sweeping the device over a printed tag or document. Machine-readable technologies such as radio frequency identification (RFID), Infra-red (IR) communication, optical character recognition (OCR) and various other types of visual, electronic and magnetic scanning are used to quickly input desired information into the WCD without the need for manual entry by a user.
Wireless communication devices employing the previously discussed characteristics may be used for a variety of applications other than basic voice communications. Exemplary applications for business may include scheduling, word processing, spreadsheets, facsimile transmission, contact management, etc. There are also a multitude applications for the personal enjoyment of the user, such as games, instant messaging, display wallpaper, etc. In addition, some newer WCDs may include resources supporting the receipt of broadcast content from a variety of sources. Broadcast sources may include such technologies as standard analog radio broadcasting, “smart” analog radio including services such as Radio Data Service (RDS) or Visual Radio, Digital Audio Broadcasting (DAB) and Digital Video Broadcasting (DVB), such as DVB for Handheld Devices (DVB-H). A user may utilize services of this type to receive a streaming broadcast of audio and/or video content directly to their WCD. This content is often be accompanied by relevant information such as the name of the program, the artist or source of the program, program duration, etc. depending on the technology employed.
Similar to a standard radio broadcasting, information received via the aforementioned streaming services is only temporarily enjoyed by the user before the next program is sent. However, there may be some cases where a user wants to record information for playback at a later time. In the case of recording standard analog radio, while the recording of broadcast content might arguably be a breach of the content owners rights, the reproduction of analog information decays with each subsequent copy, and so the resulting poor quality would eventually force patrons to seek out a licensed version. This is not the case for digital content. A recorded digital song or video program may be reproduced an unlimited number of times without any deterioration in the quality of content. As a result, there has been a very active effort by the content owners, the content providers and the organizations that represent these entities to prevent the unauthorized copying of this media.
The content owners, however, are aware of the potential market for selling select digital content directly to the consumer. Content owners have always strived to find new ways of promoting their media to possible consumers. In the case of audio programs like popular songs, increased radio airplay may result in more notoriety for a particular song, and hence, more album sales. This is true for digital media as well. Online services have profited by contracting with certain music providers to offer a wide array of digital multimedia content available for a modest fee. These content providers typically allow a subscriber to search for individual digital versions of songs that may be obtained for download to a computer, personal media player, etc.
While these services have been embraced by consumers, there are currently some drawbacks to the process. A consumer must remember information identifying the content for which they are searching before engaging the service. The searching and obtaining of desired content can be a repetitive step process, sometimes requiring a user to search more than one content provider in order to find the desired program. Further, if the information is destined for a mobile device, in most cases the user must first download the information onto a desktop or laptop computer before transfer. The sum of these requirements form a multi-step, multi-device, and possibly a multi-communication medium process that can prove to be cumbersome if a variety of content is desired.
Therefore, what is needed is a system that, at the push of a button, can identify a currently playing program from a wireless broadcast for automatic downloading to a wireless communication device. The system should record identification information for the desired program to communicate to a source for the digital content, verify user identity and/or device identity, notify a user of any required agreements or fees for the use of the content, and deliver the content to a wireless communication device with any licensing or security needed to lawfully enjoy the content. In this way, a user need not remember the program-related information often required for a cumbersome manual search to be undertaken at a later time. A simple button push delivers the content to the user quickly and automatically.
SUMMARY OF INVENTION
The present invention includes at least a system and method for facilitating the selection and downloading of a digital multimedia program based on broadcast information. A single keystroke may trigger a series of events that result in an authorized copy of the desired digital media being saved on a user device. The copy of the digital media is properly licensed so that the user may enjoy listening to this media with minimal restrictions.
In at least one embodiment of the present invention, a wireless digital content provider broadcasts multimedia content that is received by a wireless communication device. The receiving device may show information pertaining to the media that is currently being played (e.g., song name and artist). If the user desires to have a copy of this song, a single keystroke may indicate to the device to obtain the particular song.
The WCD then may record information which is used to monitor the broadcast transmission in order to determine when media matching the identification information will be broadcast. When a match is found, a copy of the media is stored in encrypted format in the memory of the WCD. This monitoring/recording may occur when the broadcast receiving applications are active (e.g., user is listening/viewing broadcast content), or in a silent mode when the WCD is engaged in other activities. Alternatively, the WCD may use the recorded information to request a copy of the desired content from a content provider.
The wireless communication device may then communicate via wireless messaging with one or both of the broadcast content provider or a digital rights manager (DRM) in order to purchase usage rights for the downloaded media. This transaction may include the DRM verifying the identification of the requestor to determine if a subscription or account exists. If provisions exist for the client to obtain the media, information is returned to the client including decryption or licensing information that will allow the WCD to decrypt the stored content for enjoyment by the user.
Other embodiments of the present invention are also disclosed wherein the above transaction occurs in a different order or through alternate means. The order of the steps may be rearranged, the steps may be altered, or additional steps may be added, depending on the characteristics of the specific application.
DESCRIPTION OF DRAWINGS
The invention will be further understood from the following detailed description of a preferred embodiment, taken in conjunction with appended drawings, in which:
FIG. 1 discloses an example of a digital broadcast system usable with at least one embodiment of the present invention.
FIG. 2 discloses a modular description of an exemplary wireless communication device usable with at least one embodiment of the present invention.
FIG. 3 discloses an exemplary structural description of the wireless communication device previously described in FIG. 2 .
FIG. 4 discloses an exemplary diagram disclosing the transmission of broadcast information to a wireless communication device in accordance with at least one embodiment of the present invention.
FIG. 5 discloses an exemplary application of a digital media distribution system in accordance with at least one embodiment of the present invention.
FIG. 6 discloses a second exemplary application of a digital media distribution system in accordance with at least one embodiment of the present invention.
FIG. 7 discloses a third exemplary application of a digital media distribution system in accordance with at least one embodiment of the present invention.
FIG. 8A discloses an exemplary flow chart describing a digital media distribution process in accordance with at least one embodiment of the present invention.
FIG. 8B discloses an exemplary flow chart describing a digital media delivery process in accordance with at least one embodiment of the present invention.
FIG. 8C discloses an exemplary flow chart describing a user verification process for a service in accordance with at least one embodiment of the present invention.
FIG. 8D discloses an exemplary flow chart describing a digital license distribution process in accordance with at least one embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENT
While the invention has been described in preferred embodiments, various changes can be made therein without departing from the spirit and scope of the invention, as described in the appended claims.
The terms “program,” “media” and “content” are used interchangeably in the following disclosure to represent various digital audio and/or video presentations that may be obtained using the present invention. Examples of these items are not limited to music, videos, movies, television shows, news and sports coverage, commercials, instructional videos, etc.
I. Wireless Media Broadcasting
The present invention operates in conjunction with a wireless broadcast system. The broadcast system may be based on traditional analog technologies (such as standard FM radio) or on digital broadcast media. A multitude of different systems are evolving in order to facilitate the wireless distribution of digital media. An example of one of these systems usable with at least one embodiment of the present invention, Digital Audio Broadcasting (DAB) using the Eureka 147 standard, is disclosed in FIG. 1 .
Digital Audio Broadcast or DAB is a standard for digital radio broadcast developed by EUREKA as a research project for the European Union. DAB uses the Eureka 147 protocol based on orthogonal frequency division modulation (OFDM) for transmitting digital data over a typically noisy radio channel. DAB broadcasts use the MP2 audio coding technique, a close relative of the popular MP3 format, which was also created as part of the EU147 project. DAB is broadcast on terrestrial networks (e.g., via a transmission tower), and may be received using solely a tiny non-directional stub antenna. The DAB system allows for the reception of audio transmissions with CD-like quality, even in a car, without any annoying interference and signal distortion typically seen in standard FM radio transmissions.
FIG. 1 . discloses an exemplary transmission system 110 and receiving system 120 . The DAB receiver device may be integrated into, or emulated by, another device such as WCD 100 also shown in FIG. 1 . Transmission system 110 encodes and then combines multiple channels of media source information by multiplexing into them a single stream, and then multiplexes this combined information with service related information. DAB transmitter 110 then employs OFDM to transmit the digital multimedia information in a bandwidth-efficient and interference-resistant format to receiver system 120 . Receiver system 120 then demodulates and decodes the OFDM signal to form media services, such as a left and right audio channel for stereo sound reproduction, data services and Program Associated Data (PAD) information.
PAD information is embedded in the audio bit stream, for data transmitted together with the audio program (e.g. lyrics). The amount of PAD is adjustable (min. 667 bit/s), at the expense of the capacity for the coded audio signal within the chosen audio bit-rate. Each audio program contains program associated data (PAD) with a variable capacity (minimum 667 bit/s, up to 65 kbit/s), which is used to convey information together with the sound program. The PAD Channel is incorporated at the end of the DAB/ISO audio frame. Typical examples of PAD applications are dynamic range control information, a dynamic label to display program titles or lyrics, speech/music indication and text with graphic features.
As stated above, DAB is just one example of a wireless broadcast system usable with the present invention. Other digital broadcast systems such as DVB-H are also included, as well as standard FM broadcast systems wherein information on current and future programming may be available via the Radio Data System (RDS, also known as “Smart Radio”) or via the Visual Radio service. Overall, the present system may be employed in any broadcast transmission system wherein information regarding current and/or future programming is provided in addition to the broadcast content.
II. Wireless Communication Device
The present invention may be implemented using a variety of wireless communication equipment. The broadcast receiver may be a device dedicated to receiving, recording and playing back digital media, or may be a device that includes these features among a variety of other functions. Therefore, it is important to understand the communication tools available to user 110 before exploring the present invention. For example, in the case of a cellular telephone or other handheld wireless communication device, the integrated data handling capabilities of the device play an important role in facilitating transactions between the transmitting and receiving devices.
FIG. 2 discloses an exemplary modular layout for a wireless communication device usable with at least one embodiment of the present invention. WCD 100 is broken down into modules representing the functional aspects of the device. These functions may be performed by the various combinations of software and/or hardware components discussed below.
Control module 210 regulates the operation of the device. Inputs may be received from various other modules included within WCD 100 . For example, interference sensing module 220 may use various techniques known in the art to sense sources of environmental interference within the effective transmission range of the wireless communication device. Control module 210 interprets these data inputs, and in response, may issue control commands to the other modules in WCD 100 .
Communications module 230 incorporates all of the communications aspects of WCD 100 . As shown in FIG. 2 , communications module 230 may include, for example, long-range communications module 232 , short-range communications module 234 and machine-readable data module 236 . Communications module 230 utilizes at least these sub-modules to receive a multitude of different types of communication from both local and long distance sources, and to transmit data to recipient devices within the broadcast range of WCD 100 . Communications module 230 may be triggered by control module 210 , or by control resources local to the module responding to sensed messages, environmental influences and/or other devices in proximity to WCD 100 .
User interface module 240 includes visual, audible and tactile elements which allow the user 110 to receive data from, and enter data into, the device. The data entered by user 110 may be interpreted by control module 210 to affect the behavior of WCD 100 . User-inputted data may also be transmitted by communications module 230 to other devices within effective transmission range. Other devices in transmission range may also send information to WCD 100 via communications module 230 , and control module 210 may cause this information to be transferred to user interface module 240 for presentment to the user.
Applications module 250 incorporates all other hardware and/or software applications on WCD 100 . These applications may include sensors, interfaces, utilities, interpreters, data applications, etc., and may be invoked by control module 210 to read information provided by the various modules and in turn supply information to requesting modules in WCD 100 .
FIG. 3 discloses an exemplary structural layout of WCD 100 according to an embodiment of the present invention that may be used to implement the functionality of the modular system previously described in FIG. 2 . Processor 300 controls overall device operation. As shown in FIG. 3 , processor 300 is coupled to communications sections 310 , 320 and 340 . Processor 300 may be implemented with one or more microprocessors that are each capable of executing software instructions stored in memory 330 .
Memory 330 may include random access memory (RAM), read only memory (ROM), and/or flash memory, and stores information in the form of data and software components (also referred to herein as modules). The data stored by memory 330 may be associated with particular software components. In addition, this data may be associated with databases, such as a bookmark database or a business database for scheduling, email, etc.
The software components stored by memory 330 include instructions that can be executed by processor 300 . Various types of software components may be stored in memory 330 . For instance, memory 330 may store software components that control the operation of communication sections 310 , 320 and 340 . Memory 330 may also store software components including a firewall, a service guide manager, a bookmark database, user interface manager, and any communications utilities modules required to support WCD 100 .
Long-range communications 310 performs functions related to the exchange of information over large geographic areas (such as cellular networks) via an antenna. These communication methods include technologies from the previously described 1G to 3G and soon fourth generation streaming video transmission. In addition to basic voice communications (e.g., via GSM), long-range communications 310 may operate to establish data communications sessions, such as General Packet Radio Service (GPRS) sessions and/or Universal Mobile Telecommunications System (UMTS) sessions. Also, long-range communications 310 may operate to transmit and receive messages, such as short messaging service (SMS) messages and/or multimedia messaging service (MMS) messages.
As a subset of long-range communications 310 , or alternatively operating as an independent module separately connected to processor 300 (not pictured), broadcast receiver 312 allows WCD 100 to receive wireless digital broadcast content via mediums such as Analog Radio, DAB, DVB-H, etc. These transmissions may be encoded so that only certain designated receiving devices may access the broadcast content, and may contain text, audio or video information. In at least one example, WCD 100 may receive these broadcasts and use information contained within the broadcast signal to determine if the device is permitted to view the received content.
Short-range communications 320 is responsible for functions involving the exchange of information across short-range wireless networks. As described above and depicted in FIG. 3 , examples of such short-range communications 320 are not limited to Bluetooth™, WLAN, UWB and Wireless USB connections. Accordingly, short-range communications 320 performs functions related to the establishment of short-range connections, as well as processing related to the transmission and reception of information via such connections.
Short-range input device 340 , also depicted in FIG. 3 , may provide functionality related to the short-range scanning of machine-readable data. For example, processor 300 may control short-range input device 340 to generate RF signals for activating an RFID transponder, and may in turn control the reception of signals from an RFID transponder. Other short-range scanning methods for reading machine-readable data that may be supported by the short-range input device 340 are not limited to IR communications, linear and 2-D (e.g., QR) bar code readers (including processes related to interpreting UPC labels), and optical character recognition devices for reading magnetic, UV, conductive or other types of coded data that may be provided in a tag using suitable ink. In order for the short-range input device 340 to scan the aforementioned types of machine-readable data, the input device may include optical detectors, magnetic detectors, CCDs or other sensors known in the art for interpreting machine-readable information.
As further shown in FIG. 3 , user interface 350 is also coupled to processor 300 . User interface 350 facilitates the exchange of information with a user. FIG. 3 shows that user interface 350 includes a user input 360 and a user output 370 . User input 360 may include one or more components that allow a user to input information. Examples of such components include keypads, touch screens, and microphones. User output 370 allows a user to receive information from the device. Thus, user output portion 370 may include various components, such as a display, light emitting diodes (LED), tactile emitters and one or more audio speakers. Exemplary displays include liquid crystal displays (LCDs), and other video displays.
WCD 100 may also include one or more transponders 380 . This is essentially a passive device which may be programmed by processor 300 with information to be delivered in response to a scan from an outside source. For example, an RFID scanner mounted in a entryway may continuously emit radio frequency waves. When a person with a device containing transponder 380 walks through the door, the transponder is energized and may respond with information identifying the device, the person, etc.
Hardware corresponding to communications sections 310 , 312 , 320 and 340 provide for the transmission and reception of signals. Accordingly, these portions may include components (e.g., electronics) that perform functions, such as modulation, demodulation, amplification, and filtering. These portions may be locally controlled, or controlled by processor 300 in accordance with software communications components stored in memory 330 .
The elements shown in FIG. 3 may be constituted and coupled according to various techniques in order to produce the functionality described in FIG. 2 . One such technique involves coupling separate hardware components corresponding to processor 300 , communications sections 310 , 312 and 320 , memory 330 , short-range input device 340 , user interface 350 , transponder 380 , etc. through one or more bus interfaces. Alternatively, any and/or all of the individual components may be replaced by an integrated circuit in the form of a programmable logic device, gate array, ASIC, multi-chip module, etc. programmed to replicate the functions of the stand-alone devices. In addition, each of these components is coupled to a power source, such as a removable and/or rechargeable battery (not shown).
The user interface 350 may interact with a communications utilities software component, also contained in memory 330 , which provides for the establishment of service sessions using long-range communications 310 and/or short-range communications 320 . The communications utilities component may include various routines that allow the reception of services from remote devices according to mediums such as the Wireless Application Medium (WAP), Hypertext Markup Language (HTML) variants like Compact HTML (CHTML), etc.
When engaging in WAP communications with a remote server, the device functions as a WAP client. To provide this functionality, the software components may include WAP client software components, such as a Wireless Markup Language (WML) Browser, a WMLScript engine, a Push Subsystem, and a Wireless Medium Stack.
Applications (not shown) may interact with the WAP client software to provide a variety of communications services. Examples of such communications services include the reception of Internet-based content, such as headline news, exchange rates, sports results, stock quotes, weather forecasts, multilingual phrase dictionaries, shopping and dining information, local transit (e.g., bus, train, and/or subway) schedules, personal online calendars, and online travel and banking services.
The WAP-enabled device may access small files called decks which each include smaller pages called cards. Cards are small enough to fit into a small display area that is referred to herein as a microbrowser. The small size of the microbrowser and the small file sizes are suitable for accommodating low memory devices and low-bandwidth communications constraints imposed by wireless links.
Cards are written in the Wireless Markup Language (WML), which is specifically devised for small screens and one-hand navigation without a keyboard. WML is scaleable so that it is compatible with a wide range of displays that covers two-line text displays, as well as large LCD screens found on devices, such as smart phones, PDAs, and personal communicators. WML cards may include programs written in WMLScript, which is similar to JavaScript. However, through the elimination of several unnecessary functions found in these other scripting languages, WMLScript reduces memory and processing demands.
CHTML is a subset of the standard HTML command set adapted for use with small computing devices (e.g., mobile communicator, PDA, etc.). This language allows portable or handheld devices interact more freely on the Internet. CHTML takes into consideration the power, processing, memory and display limitations of small computing devices by stripping down standard HTML to a streamlined version suitable for these constraints. For example, many of the more advanced image maps, backgrounds, fonts, frames, and support for JPEG images have been eliminated. Further, scrolling is not supported because it is assumed that CHTML displays will fit within the screen of a portable device. CHTML has also been designed to operated without two dimensional cursor movement. Instead, it may be manipulated with only four buttons, which facilitates its implementation over a larger category of small computing devices.
III. Transmission of Program-related Information
FIG. 4 discloses an example of a wireless broadcast that may be received by a device like WCD 100 . Digital Radio/TV station 414 may broadcast a continuous schedule of audio and/or video programs for the enjoyment of the end user. Each audio and/or video data file is stored, converted and compiled, by supporting equipment 412 , into a serial stream of programs for wireless broadcast via one of the previously discussed wireless transmission standards. FIG. 4 depicts broadcast transmission 400 traveling directly from transmission tower 410 to receiving WCD 100 , however, certain systems may include an intermediary delivery system such as a satellite (not pictured). These systems, such as Sirius™ and XM™ satellite radio, deliver a variety of broadcast content to satellite receivers in located in cars, homes, etc.
Broadcast transmissions 400 and 402 deliver content to WCD 100 . In broadcast 400 , the transmission includes both the multimedia content and PAD information composed in one digital signal that is decoded into separate information streams by the receiving device. PAD information may be received in a multitude of different formats such as Electronic Program Guide (EPG) information, Electronic Service Guide (ESG) information, Service information (SI) and Program Specific Information (PSI) for DVB-based systems, etc. Tuner or chooser software resident in WCD 100 may use the PAD information to create a selector for describing the available channels and/or programs that may be experienced by a user. The tuner software may then use the PAD information received by WCD 100 to select a certain channel from which to receive multimedia programs. In listening and/or viewing programs from a designated channel, the software may also display the name of the currently tuned channel, the name of the content currently playing or to be played next, the name and the artist/creator of the content currently being played or to be played next, album or volume names, the playing duration of the content playing or to be played next, and other content related information.
The total of the broadcast information may also be received via a combination of two or more wireless mediums. Broadcast 402 shows an example of the broadcast content and related information being transmitted separately to WCD 100 . This strategy may be employed in the case of analog radio communications, wherein the content signal comes via typical analog AM/FM or shortwave transmission, and additional program information is received via an RDS or Visual Radio receiver on a separate broadcast signal. The result is that an RDS radio receiver may identify the name and the artist of the current and/or next song to be displayed on the receiving device, as well as perform other smart functions like finding the same program on another channel, interrupting transmission with weather emergency announcements, etc. Visual Radio offers similar features, though the implementation may be different. In the case of Visual Radio, the content-related data may be provided via a digital medium like GPRS or another digital wireless medium. In the digital realm, PAD information like EPG, ESG, SI and PSI may also be sent via a distinct wireless medium like GPRS. This information is transmitted in parallel to the main digital program feed, and is used to communicate information related to the received content for display on WCD 100 .
IV. Digital Media Distribution
An exemplary system for the wireless distribution of digital media, in accordance with at least one embodiment of the present invention, is disclosed in FIG. 5 . Digital Radio/TV station provides broadcast 400 which may be received by devices such as WCD 100 . While a digital radio/TV station is used in this example, as analog radio broadcast equipped with the RDS information service may also be applied as previously described.
WCD 100 includes tuner or chooser software 416 . This software decodes the incoming broadcast 400 to separate content and related information streams. A user listening to the broadcast 400 may view information on current or pending content on the display of WCD 100 . If the user desires to obtain a copy of the content (e.g., a song, video, offer, schedule, coupon, story, etc.) so that it may be played at the user's convenience, the user may depress “record” key (shown at 510 ) on WCD 100 to indicate that a licensed copy of the desired program should be requested.
Pressing record key 510 triggers WCD 100 to save the identification information related to the program to be played next. The device may then monitor the incoming broadcast PAD information to determine when the identification information of the broadcast content currently being played matches the stored identification of the desired program. When the current program matches the desired content, WCD 100 may save the incoming content in an encrypted form to memory 330 . This monitoring/recording functionality may be triggered by a user when WCD 100 is being used to actively consume incoming broadcast content, however, the recording does not necessary have to occur during this active mode. WCD 100 may continue to monitor incoming broadcasts without having active any applications related to the actual playing of a broadcast, and in this passive or “silent” mode, may still record content desired by the user. A typical scenario where a passive or “silent” mode recording may be required is when the user requests a plurality of programs, wherein the downloading of these programs may need to occur over an extended period of time.
Memory 330 , wherein programs may be stored, encompasses all forms of device memory both permanent and removable. These recorded programs may be stored and organized by any user-determined characteristic, including information taken from the stored PAD information. For example, a user may configure WCD 100 to store audio programs first by artist and then album, video content by title, etc.
About the same time the desired program is being stored, WCD 100 may also send a wireless message to a digital rights manager (DRM) 500 . The message may be sent via any of the long-range or short-range wireless communication mediums previously described. For example, the message may be an email through a wireless connection to the Internet, long range communications through 3G technologies like GPRS or SMS, a short-range connection to a local access point via Bluetooth™, WLAN, etc. The message may contain information pertaining to the desired content, the author or owner of the desired content, a user identification, an account identification, a device identification, a wireless service provider identification and encryption information related to the stored content. Further, DRM 500 is depicted separately from digital radio/TV station 414 in FIG. 5 , however, these functions may be combined in the same entity.
DRM 500 initially checks to determine whether user and/or account information usable in the purchase the desired program is recorded. To do this, the information in the electronic message may be compared to stored records to determine if the user has already set up an account. If no information exists, DRM 500 may request more information from the user. If billable information is already established, DRM 500 may then define a decryption key based on information related to one or more of the user ID, the device ID, the encryption type, the program ID, the artist/creator ID, etc. More specifically, the encryption key may be created to verify one or more of the previous variables when activated, and if the verification fails (e.g., the actual device identification does not match the expected device identification), the key will not allow the content to be decoded. The record of the transaction is stored for billing the user's account, and the decryption information is sent back to WCD 100 via a wireless message.
WCD 100 receives the wireless message including the decryption key from DRM 500 . The decryption information is used to decode the encrypted stored content for use on WCD 100 through, for example, digital media player 512 . Depending on the distribution strategy employed by DRM 500 , the content may be decrypted initially and then may reside on WCD 100 in a unsecured form, or alternatively, the stored content may require the decryption key every time the content is used. This latter system is advantageous for the content owner because while a user may download a licensed copy of the content, it would be extremely difficult to copy the program onto other devices. Each subsequent device would also need a similar decryption key, which as previously stated, may be encoded to require the verification of certain variables related to a current user and/or device before decrypting the content.
FIG. 6 is a similar digital media distribution system to FIG. 5 , except that in the example of FIG. 6 the order of some of the steps have been altered, and additional steps have been added, to better accommodate the requirements of the user. The user still indicates via record button 510 the future content to be played. However, in this case the feasibility of the transaction is first verified with DRM 500 in steps 1 - 8 . Confirming the transaction before downloading the desired program in encrypted form prevents the needless consumption of wireless bandwidth and memory 330 in WCD 100 if the user does not have an account with DRM 510 , does not want to start an account with DRM 510 , does not have sufficient funds to pay for the content, etc.
After it is verified that the transaction can occur, the content may then be downloaded by matching the desired content information to the information of the content currently playing as previously described. Once the content and the decryption key have been received by WCD 100 , the use of the decryption key to play the downloaded program may trigger a subsequent message to DRM 500 confirming that both the encrypted content and decryption key were received and used successfully, and as a result, the user may now be billed for the content. This final additional confirmation step allows DRM 500 to confirm that all parts of the transaction were successfully completed before billing the customer, which may prevent future requests from the customer for account credits due to incomplete or corrupt downloads.
FIG. 7 is a further example application of the present invention including an additional communication transaction with digital radio/TV station 414 in step 5 ( a ). The information reported to station 414 may include the name of the desired content, information related to the creator/owner of the content, requestor identification information, etc. Station 414 may use this information for a variety of applications. For example, when the broadcast medium includes standard analog FM broadcasts including RDS, WCD 100 may, in lieu of recording a copy of the desired content directly from the broadcast signal, have a desired program request fulfilled by station 414 , wherein the encrypted content may sent to the requestor via the same or an alternative medium, for example, GPRS, as an email attachment or via another wireless medium capable of transporting the encrypted file. Alternatively, a web link may be included in a return message for the user to download the desired content at their leisure. The user identification may also be stored for use in contests, for example, where a user who downloads a song is entered in a raffle to win a prize. Station 414 may further compile this information to determine future play lists, wherein content that is in higher demand will be played more often by digital radio/TV station 414 . Further, compiled statistics may be used to determine any fees or royalties that are owed to the content owner for airplay of their content.
The process of execution for at least one embodiment of the present invention is shown in FIG. 8A-8D . In step 800 , radio/TV station 414 broadcasts information including both program content and PAD information. A user may consume the audio and/or video programs and determine whether the content is something they want to purchase in steps 810 and 812 . If the broadcast content should be downloaded, the user indicates interest by pressing a record button in step 814 , which begins the process. In step 816 , a wireless message is then sent to DRM 500 including information related to one or more of the desired content, user and device.
In at least one embodiment of the invention, the device may download the desired content in step 822 . This process is discussed in more detail in FIG. 8B under the reference “A.” When the record button is depressed in step 814 , information related to the desired content is stored in memory 330 of WCD 100 (step 900 ). The receiving communication device may then monitor incoming programs in step 910 to determine whether the PAD information of these future programs matches the saved information form the desired content. If the incoming information does not match in step 920 , then the device continues to check, if a match is made, then WCD 100 begins to download the broadcast information in encrypted form (step 930 ). It is important to note that, as previously stated, this process may occur in an active mode (e.g., when the user is listening or viewing the broadcast content) or in a passive or “silent” mode when WCD 100 may be engaged in performing other functions. The download completes in step 940 and the process moves to DRM 500 receiving a wireless electronic message in step 818 .
As previously recited in step 816 , the pressing of the record button may cause a wireless message to be sent from WCD 100 to DRM 500 . The processing of this message is described in step 818 , with the details of the processing shown in FIG. 8C under the reference “B.” The wireless message to DRM 500 is received in step 1000 . As previously discussed, DRM 500 and broadcast station 414 may be one in the same, or separate entities. DRM 500 may, in step 1010 , verify whether the user indicated in the received wireless message is already known to the DRM (e.g., a previously registered user who may have already purchased media through the process of the present invention).
If the user is unknown, then in step 1030 DRM 500 may request more information from the user in order to establish an account. This information may include well-known identification and billing information such as name, address, telephone number, credit card number, etc. This information may be received in step 1060 . In another example (not pictured), step 1030 may simply inquire with the user as to whether DRM 500 has permission to bill the user's service provider account (e.g., a cellular service provider) for the requested program. Step 1020 shows an alternate situation wherein the user has account information already established with DRM 500 . In this case, DRM 500 may simply check to determine whether the user has the ability to purchase the desired media. In the case where an account must be “loaded” (e.g., where the user must deposit funds in the account from which purchase costs are drawn) the declining balance may be depleted. If this is the case, then in step 1050 the user may be notified via a wireless message to place more funds in the account.
Given the success of establishing a user account via either of the previously recited methods, a charge for purchasing the desired program may then be established in step 1070 . The user may then receive an electronic wireless message indicating that the media that was purchased, that their account has been charged, the amount that has been charged to the account, etc. This message may be sent at the same time, or separately from, the decryption key that will now be described in step 820 of FIG. 8A , with the details of the processing shown in FIG. 8D under the reference “C.”
In FIG. 8D , DRM 500 determines a decryption code that is eventually delivered to WCD 100 via wireless communication. In steps 1100 - 1120 , DRM 500 may use information including user identification, account identification, device identification, service provider identification, content identification, time, date, encryption type information, etc. to formulate a decryption key. The decryption key may then, when invoked by the user, verify current information related to one or all of the components used to compose the key. This provision may ensure that, while the user may enjoy the desired media on WCD 100 at any time, that the media may not be copied from WCD 100 to another device without purchase (e.g., without receiving a new decryption key from DRM 500 ), which achieves a compromise so that both the content owner and the user may be satisfied.
In step 1130 the decryption key, a receipt of the transaction and possibly license and instructional information are sent to WCD 100 via a wireless messaging transaction. This transaction may occur via any of the wireless messaging mediums previously discussed. Again referring to FIG. 8A , in steps 822 and 824 , the user receives this information, and may use the decryption key to decrypt the downloaded content so that it may be viewed and/or listened to on WCD 100 .
A described in FIG. 5-7 , other embodiments of the present invention may slightly rearrange or alter the previously described process flow. In some cases the content may be downloaded at a later time, such as after DRM 500 confirms that the transaction may proceed. Further, an additional step may be included after the decryption key is first employed to confirm back to DRM that the encryption key was received and is functional. These steps, and others, may be altered depending on the particular application to which the present invention is applied.
The present invention is an improvement over existing systems because it streamlines the process of digital content distribution into a form easily employable by a user. A single button may automatically trigger a process that previously required multiple manual steps, and in some cases, multiple devices communicating on multiple platforms. With the present invention, all parties in the transaction are benefited. For example, the broadcast provider may learn what content is most desired by consumers, the content owner may receive compensation for the controlled provision of their content to the consumer, and the consumer is granted the ability to very simply request and receive digital content that is legally provided for their enjoyment at any time.
Accordingly, it will be apparent to persons skilled in the relevant art that various changes in forma and detail can be made therein without departing from the spirit and scope of the invention. The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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The present invention is a system for facilitating the selection and downloading of a digital multimedia program based on broadcast information. A single keystroke may trigger a series of events that result in an authorized copy of the desired digital media being saved on a user device. The desired program is wirelessly downloaded in an encrypted format, and after an accounting and billing process transpires, a decryption key is delivered in to the user device in a wireless message. The copy of the desired digital media is then decrypted, and is properly licensed, so that the user may enjoy listening to this media with minimal restrictions.
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CLAIMING BENEFIT OF PRIOR FILED U.S. APPLICATION
This application claims the benefit of U.S. Provisional Application Ser. No. 61/155,740, filed on Feb. 26, 2009. The content of this document and the entire disclosure of publications, patents, and patent documents mentioned herein are incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the drawing of molten glass into a glass sheet, and in particular, to controlling the mass flow rate of the molten glass as it flows over a forming body and is drawn through downstream appliances.
2. Technical Background
One method of producing high quality sheets of glass is by the fusion downdraw method. Molten glass is flowed over converging forming surfaces of a forming body, wherein the molten glass fuses at the line where the converging forming surfaces meet to produce a glass ribbon. Drawing equipment positioned downstream of the forming body pull the ribbon downward, and individual glass sheets are cut from the continuous ribbon.
Maintaining the dimensional stability of the glass ribbon involves an intricate relationship between the mass flow distribution of the molten glass flowing over the forming body, the temperature control of the molten glass and the ribbon
SUMMARY
In one embodiment, an apparatus for forming a sheet of glass is described including a forming body comprising a trough and converging forming surfaces that join at a root such that molten glass overflowing the trough forms multiple streams of molten glass that flow over the converging forming surfaces and combine at the root to form a glass ribbon, and wherein the forming body can be tilted relative to a horizontal plane. The apparatus further comprises an upper transition member coupled to the forming body defining a first interior space through which the glass ribbon descends, and wherein the upper transition member can be tilted and a lower transition member positioned below the upper transition member, the lower transition member defining a second interior space through which the glass ribbon descends. The upper transition member and the lower transition member are separated by a gap less than 8 cm and wherein the gap is positioned such that a viscosity of the glass ribbon adjacent to the gap is equal to or less than about 10 7.3 poise, and preferably also greater than about 10 5.7 poise. Preferably the gap between the upper and lower transition members is equal to or less than about 8 cm, and more preferably less than about 3 cm.
The forming body and the upper transition member may be tilted in unison, and may be rigidly coupled.
To prevent air from leaking into the interior spaces of the transition members and disrupting the thermal environment within the transition members, an insulating blanket disposed between the upper and lower transition members. A flexible sealing member or membrane may be coupled to the upper and lower transition members and covering the gap to further prevent air leakage through the gap and to help retain the insulating blanket in position.
In addition to movement of the upper transition member, the lower transition member may be vertically movable relative to the horizontal plane. However, the upper transition member and lower transition member are independently moveable from each other. Thus, tilting of the upper transition member and vertical translation of the lower transition member may be conducted independently from each other.
In another embodiment, a method of balancing the mass flow rate of molten glass flowing over the surfaces of a forming body is disclosed.
The forming body comprises a trough and converging forming surfaces that join at a root such that molten glass overflowing the trough forms multiple streams of molten glass that flow over the converging forming surfaces and combine at the root to form a glass ribbon.
The method is characterized by the steps of tilting the forming body relative to a horizontal plane in response to a change in a mass flow rate of the molten glass flowing over the converging forming surfaces, tilting an upper transition body relative to the horizontal plane, the upper transition member positioned below and coupled to the forming body.
The glass ribbon is drawn through a first interior space defined by the upper transition member and a second interior space defined by a lower transition member positioned below the upper transition member. The upper transition member and the lower transition member are separated by a gap less than 8 cm and wherein the gap is positioned such that a viscosity of the glass ribbon horizontally adjacent to the gap is equal to or less than about 10 7.3 poise. For example, the gap may be positioned such that a viscosity of the glass ribbon horizontally adjacent to the gap is equal to or less than about 10 7 poise, equal to or less than about 10 6.5 poise, or equal to or less than about 10 6 poise.
According to the present embodiment, the upper and lower transition members may be independently moveable, wherein the lower transition member may be translated vertically relative to the horizontal plane, but not tilted while drawing the glass ribbon. In some instances the gap may be made equal to or less than 3 cm. In another embodiment, the lower transition member can be tilted.
The invention will be understood more easily and other objects, characteristics, details and advantages thereof will become more clearly apparent in the course of the following explanatory description, which is given, without in any way implying a limitation, with reference to the attached Figures. It is intended that all such additional systems, methods features and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view and partial cross section of an exemplary forming body for use in a fusion downdraw glass sheet forming apparatus.
FIG. 2 is a side elevation view of a sheet forming apparatus according to an embodiment of the present invention.
FIG. 3 is a perspective view of the upper transition member of the apparatus of FIG. 2 .
FIG. 4 is a perspective view of the lower transition member of the apparatus of FIG. 2
FIG. 5 is a side elevation view of a fusion downdraw apparatus comprising a single transition member, wherein tilting of the forming body results in a tilting of the entire apparatus, a possible flow disruption of the molten glass.
FIG. 6 is a close up cross sectional view of a portion of the upper and lower transition members showing a two layer insulating blanket. Disposed between the transition members.
FIG. 7 is a side elevation view of the apparatus of FIG. 2 showing tilt of the muffle, forming body and upper transition member without tilting of the lower portions of the apparatus (e.g. the pulling rollers and the lower transition member).
DETAILED DESCRIPTION
In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one having ordinary skill in the art, having had the benefit of the present disclosure, that the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. Moreover, descriptions of well-known devices, methods and materials may be omitted so as not to obscure the description of the present invention. Finally, wherever applicable, like reference numerals refer to like elements.
As used here, unless otherwise defined, “above” and “below” are referenced in absolute terms to the surface of the earth. The terms may also relate relatively to objects in the same reference system. Thus, a first object one meter above the ground vertically beneath the object would be 1 meter above the ground surface, and an object 2 meters above the ground vertically over the first object would also be above the ground surface, but the first object would be below the second object.
One method of making glass sheet is by a fusion downdraw process, so called because a glass flow is caused to separate into two separate streams of molten glass that flow over a forming body. The streams are then rejoined, or fused, at the bottom of the forming body to produce the glass sheet. This can be more clearly understood with the benefit of FIG. 1 illustrating an exemplary forming body that may be used in a fusion downdraw glass making process.
FIG. 1 depicts forming body 10 comprising a channel or trough 12 formed in an upper portion of the body framed by side walls 14 , and converging forming surfaces 16 a and 16 b that meet at root 18 extending along a length of the forming body. Molten glass 20 is introduced into trough 12 and overflows side walls 14 on both sides of the forming body, creating two separate streams of molten glass that flow down and over the forming body. The two separate molten glass streams flow over converging forming surfaces 16 a and 16 b , and meet at root 18 , where root 18 is a line formed by the convergence of the converging forming surfaces. The streams rejoin, or fuse, at the root to produce a single stream that flows downward from the root as pristine glass ribbon 22 . The molten glass that has been in contact with the surfaces of the forming body (e.g. the converging forming surfaces) is disposed within the interior portion of the resultant ribbon, whereas the outer surfaces of the ribbon have not contacted the forming surfaces.
FIG. 2 illustrates fusion draw apparatus 30 comprising forming body 10 of FIG. 1 . In addition to forming body 10 , fusion draw apparatus 30 comprises muffle 32 enclosing forming body 10 , upper transition member 34 defining first interior space 36 ( FIG. 3 ), lower transition member 38 defining second interior space 40 ( FIG. 4 ) and rollers for drawing the sheet downward represented by pulling roller set 42 (pulling roller set 42 constitutes two pair of the pulling roller sets shown on opposite sides of the ribbon, such that the ribbon is pinched between the opposing rollers). Muffle 32 , upper transition member 34 and lower transition member 38 , in combination with various heating and cooling appliances (not shown) disposed within the muffle and transition bodies, serve to regulate the thermal environment surrounding glass ribbon 22 as it is drawn from forming body root 18 and down through the upper and lower transition members. The ability to control the thermal environment of the ribbon, and particularly the thermal environment in the temperature range over which the glass ribbon cools and transitions from a visco-elastic material to an elastic material, allows the manufacture of thin sheets of glass of very high quality. The temperature range where 90% of the high temperature stresses will be retained at room temperature. It is calculated considering the effect of cooling rates and glass visco-elastic properties. That is, for higher cooling rates (e.g. draw velocities) the setting zone goes hotter and smaller.
According to the embodiment of FIG. 2 , muffle 32 , upper transition member 34 and forming body 10 are physically coupled so that the components can move as a unit. Moreover, muffle 32 , upper transition member 34 and forming body 10 can be tilted relative to horizontal plane 46 to balance the mass flow rate of molten glass flowing over forming body 10 as a function of position along the length of the forming body. Tilting can be performed, for example, by supporting at least one end of the coupled muffle-forming body-transition member assembly via jack screws. For example, in response to a change or disruption in mass flow rate of molten glass over the forming body, the forming body can be tilted as needed to redistribute the molten glass flowing over the length of the forming body (from one end to the other end) to maintain a consistent thickness of glass ribbon 22 .
FIG. 5 illustrates a hypothetical fusion draw apparatus 50 comprising a single transition member 52 , forming body 10 , muffle 32 and pulling rollers 42 , and wherein forming body 10 , muffle 32 , pulling rollers 42 and single transition member 52 are rigidly coupled together through a frame (not shown) so that to tilt forming body 10 the entire apparatus 50 must be tilted. In the example of FIG. 5 , a tilted condition results in two nonparallel drawing forces act on the glass ribbon, a vertical gravitation force g and the pulling force n applied by pulling rollers 42 . The result of the two nonparallel drawing forces can create a flow instability in the molten glass, and a horizontal shift of the ribbon. In extreme cases, the horizontal shift may cause contact with single transition member 52 .
In accordance with the embodiment of FIG. 2 , to facilitate tilting of the forming body and upper transition member without disturbing the flow dynamics of the ribbon, and to prevent contact with the transition housing, a two-piece transition housing for apparatus 30 comprising upper transition member 34 and lower transition member 38 is provided. Upper transition member 34 and lower transition member 38 are separated from each other by gap δ. Because of the difficulty of positioning heating and/or cooling appliances within gap δ and still accommodate tilting of upper transition member 34 , gap δ is made as narrow as possible. To that end, the maximum separation between the upper and lower transition members (i.e. gap δ) is preferably less than 8 cm, but may vary depending on the degree of tilt by the upper transition member. For example, when upper transition member 34 is in a nominal position (horizontally level), gap δ is preferably equal to or less than 3 cm, typically about 2.5 cm.
An insulating blanket 54 (shown in a close-up cross section detail of upper and lower transition members 34 , 38 in FIG. 6 as two layers) may be disposed in gap δ between upper transition member 34 and lower transition member 38 to prevent ambient air from leaking through the gap that might disrupt the thermal environment within the transition bodies. The insulating blanket forms a flexible, and preferably compressible barrier between the upper and lower transition members that can accommodate movement between the upper and lower transition bodies, while continuing to prevent airflow through the gap δ. Insulating blanket 54 may, for example, comprise one or more layers of an inorganic fiber material, such as those sold by the Unifrax Corporation under the trade name Fiberfrax® Durablanket®. However, any high temperature-resistant insulating material having sufficient flexibility and compressibility to withstand the rigors of the process described above may be used. An optional flexible sealing member 56 may be coupled to the upper transition member and the lower transition member to form an additional barrier over gap 6 that prevents air flow and heat loss through the gap. FIGS. 2 and 7 are shown without insulating blanket 54 , and portions of sealing member 56 so as to not obstruct other portions of the figure. For example, in practice sealing member 56 may be extended around the entire perimeters of upper and lower transition members 34 , 38 over gap 6 .
In some embodiments, lower transition member 38 can move vertically, but is not configured to tilt as is the upper transition body. Preferably, pulling rollers 42 are also capable of vertical movement, and more preferably are capable of moving in unison with lower transition member 38 , when coupled through supporting framework (not shown). For example, in some instances the positions of lower transition member 38 and pulling rollers 42 may be vertically adjusted to accommodate the tilt applied to upper transition member 34 .
In other embodiments, the lower transition member can be tilted independently from the upper transition member (that is, both the upper and lower transition members are independently tillable). This can be desirable if a different order of operation is performed. For example, the upper and lower transition members may be connected, such as by jack screws, so that the upper and lower transition members are first tilted in unison. Once the initial tilt is performed, the jack screws are temporarily released and the lower transition is tilted (re-leveled) so that the lower transition is again vertical (or the upper edge of the lower transition member adjacent gap δ is back in a horizontal plane). The upper and lower transition members may then be reconnected in the new configuration.
To minimize any disruption to the glass ribbon as it descends through the setting zone, the length of upper transition member 34 is configured such that gap δ is positioned where the viscosity of the glass ribbon horizontally adjacent to the gap is equal to or less than a viscosity V max of about 10 7.3 poise. For example, the gap may be positioned such that the viscosity of the glass ribbon horizontally adjacent to the gap is equal to or less than a V max of about 10 7 poise, equal to or less than a V max of about 10 6.5 poise, or equal to or less than a V max of about 10 6 poise. Preferably, gap δ may further be positioned where a viscosity of the glass ribbon horizontally adjacent to the gap is equal to or greater than a viscosity (V min ) of about 10 5.7 poise. Thus, for example, the gap may be positioned horizontally adjacent a location of the ribbon where the viscosity of the ribbon is between V min and V max , e.g. 10 7.3 poise and 10 5.7 poise, between 10 7 poise and 10 6.5 poise, between 10 6.5 poise and 10 5.7 poise, or between 10 6 poise and 10 5.7 poise.
It should be emphasized that the above-described embodiments, 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 embodiments 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 this disclosure and the present invention and protected by the following claims.
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Apparatus and method for balancing the mass flow rate of molten glass flowing over a forming body to form a glass ribbon. The apparatus comprises upper and lower transition members that surround the glass ribbon as the glass ribbon is drawn from the forming body. The upper and lower transition members are independently moveable, and separated by a gap less than 8 cm across. The narrow gap minimizes disruption to the thermal environment contained within the upper and lower transition members, and is positioned a sufficient distance above the setting zone of the ribbon to minimize any influence on the dimensional consistency of the ribbon.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/613,726, now issued U.S. Pat. No. 8,827,060 filed Sep. 13, 2012, the disclosure of which is hereby incorporated in its entirety by reference herein.
TECHNICAL FIELD
The present disclosure relates to a system and method to control ratio changes in an automatic vehicle transmission.
BACKGROUND
Known automatic transmissions for automotive vehicles include step ratio controls for effecting speed ratio changes in response to changing driving conditions. The term “speed ratio”, for purposes of this description, is defined as transmission input shaft speed divided by transmission output shaft speed.
An upshift occurs when the driving conditions require a ratio change from a lower numbered ratio (high speed ratio) to a higher number ratio (low speed ratio) in the transmission gearing. Similarly, a downshift occurs when the driving conditions require a ratio change from a higher numbered ratio (low speed ratio) to a lower number ratio (high speed ratio). The gearing can include, for example, either a planetary type gear system or a lay shaft type gear system. An automatic gear ratio shift is achieved by friction torque establishing devices, such as multiple disk clutches and multiple disk brakes. The friction torque establishing devices include friction elements, such as multiple plate clutches and band brakes, which can be actuated hydraulically.
A step-ratio automatic transmission uses multiple friction elements for automatic gear ratio shifting. A ratio change occurs in a synchronous clutch-to-clutch shift as one friction element, which may be referred to as the oncoming clutch (OCC), is engaged and a second friction element, which may be referred to as the off-going clutch (OGC), is disengaged. Failure to properly coordinate the engagement of the OCC with the disengagement of the OGC can be perceived by the vehicle occupants as an unpleasant shift event. More particularly, early engagement of the OCC relative to the release of the OGC can result in a phenomenon called tie-up. On the other hand, if the OCC is engaged too late relative to the release of the OGC, an engine flare can occur.
SUMMARY
In one embodiment, a method for controlling a transmission is provided. The method ensures proper clutch stroke and minimizes torque transients. During a downshift, a clutch pressure is set for an oncoming clutch at a predetermined stroke pressure. Then the clutch pressure is varied from the predetermined stroke pressure. A resulting torque difference is measured along a torque transmitting element with a torque sensor while the clutch pressure is varied. A clutch control parameter is adjusted if the resulting torque difference is less than a threshold value.
In another embodiment, the torque transmitting element can be, for example, an input shaft or an output shaft.
In yet another embodiment, varying the clutch pressure can involve pulsing the clutch pressure above the predetermined stroke pressure, pulsing the clutch pressure below the predetermined pressure, gradually increasing the clutch pressure in a ramp profile, or other means.
In some embodiments, the method can include setting the clutch pressure at a boost pressure higher than the predetermined stroke pressure for a boost duration before setting the clutch pressure at the predetermined stroke pressure.
In still another embodiment, the clutch control parameter to be adjusted can be, for example, the predetermined stroke pressure, the boost pressure, or the boost duration.
In one other embodiment, a method for controlling a transmission is provided. The method includes varying a clutch pressure around a predetermined value in advance of a torque phase of a shift event. A torque change is measured in a transmission element as the clutch pressure is varied. A clutch control parameter is adjusted in response to the measured torque change.
In another embodiment, the value can be increased if the change in measured torque is below a first threshold.
In another embodiment, the value can be decreased if the change in measured torque is above a second threshold.
In another embodiment, the shift event can be a downshift and the clutch can be the oncoming clutch for the downshift.
In on other embodiment, a transmission is provided. The transmission includes a clutch having a torque capacity based on a fluid pressure and a torque sensor adapted to measure a torque value that varies in relationship to the torque capacity. A transmission controller is configured to vary the fluid pressure from a predetermined value in advance of a torque phase of a shift event and adjust the predetermined value in response to a change in the measured torque value.
The above advantages and other advantages and features will be readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating a transmission;
FIG. 2 is a schematic diagram of a transmission clutch or brake;
FIG. 3 is a graph illustrating a downshift under idealized clutch pressure control;
FIG. 4 is a graph illustrating a downshift under open loop clutch pressure control in which the oncoming clutch pressure is set too high;
FIG. 5 is a graph illustrating a downshift under open loop clutch pressure control in which the oncoming clutch pressure is set too low;
FIG. 6 is a flow chart illustrating a first embodiments of a closed loop pressure control algorithm;
FIG. 7 is a graph illustrating a downshift under the closed loop clutch pressure control system of FIG. 6 in which the initial oncoming clutch pressure is set too high;
FIG. 8 is a graph illustrating a downshift under the closed loop clutch pressure control system of FIG. 6 in which the initial oncoming clutch pressure is set too low;
FIG. 9 is a flow chart illustrating a second embodiments of a closed loop pressure control algorithm; and
FIG. 10 is a graph illustrating a downshift under the closed loop clutch pressure control system of FIG. 9 .
DETAILED DESCRIPTION
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely examples of the invention that can be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
FIG. 1 illustrates a six speed planetary transmission 18 with three planetary gear sets 20 , 22 , and 24 . Each planetary gear set includes a sun gear, a ring gear, a planet carrier, and a collection of planet gears supported for rotation about the planet carrier and meshing with both the sun gear and the ring gear. The carrier of gear set 20 is fixedly connected to the ring gear of gear set 22 , the carrier of gear set 22 is fixedly connected to the ring gear of gear set 24 , and the carrier of gear set 24 is fixedly connected to the ring gear of gear set 20 . Input shaft 26 is fixedly connected to the sun gear of gear set 22 and output shaft 28 is fixedly connected to the carrier of gear set 24 .
Various power flow paths between input shaft 26 and output shaft 28 are established by the selective engagement of clutches and brakes. Brakes 30 , 32 , and 34 selectively hold the sun gear of gear set 20 , the carrier of gear set 20 , and the sun gear of gear set 24 , respectively, against rotation. Clutches 36 and 38 selectively connect the sun gear of gear set 20 and the carrier of gear set 20 , respectively, to input shaft 26 . Table 1 indicates which clutches and brakes are engaged in order to establish each of the six forward and one reverse transmission ratios. Torque sensor 40 senses the torque transmitted to the output shaft and electrically communicates that information to controller 42 . The controller 42 can, for example, be part of a vehicle system control module or transmission control module or can be a stand-alone controller.
TABLE 1
Brake 30
Brake 32
Brake 34
Clutch 36
Clutch 38
Reverse
X
X
1st
X
X
2nd
X
X
3rd
X
X
4th
X
X
5th
X
X
6th
X
X
While an automatic transmission according to an embodiment of the disclosure can be a planetary type as shown in FIGS. 1 , it is also contemplated that the transmission can be a lay shaft type transmission. Similarly, a speed ratio change can be achieved by the friction elements as described above, or the friction elements can be plate clutches or band brakes.
FIG. 2 illustrates a representative cross section of a clutch, such as clutches 36 and 38 and brakes 30 , 32 , and 34 in FIG. 1 . A set of friction plates 44 is splined to a clutch hub 46 . The friction plates 44 are interspersed with a set of separator plates 48 that is splined to a clutch cylinder 50 . In the disengaged state as shown here in FIG. 2 , there is space between the friction plates 44 and the separator plates 48 such that the hub 46 and the cylinder 50 are free to rotate at different speeds with respect to each other.
To engage the clutch, pressurized fluid is forced into the cylinder 50 . The pressure is supplied by a pump 52 . The controller 42 regulates the hydraulic pressure indirectly by setting an electrical current in a solenoid 54 which controls the position of a valve 56 . The pressurized fluid travels through a hydraulic passageway 58 to the clutch cylinder 50 . The pressurized fluid forces the piston 60 to slide within the cylinder 50 and squeeze the friction plates 44 and separator plates 48 together. Friction between the friction plates 44 and the separator plates 48 resists relative rotation of hub 46 and cylinder 50 . When the fluid pressure is removed, a return spring 62 forces the piston 60 to slide in the opposite direction returning the clutch to the disengaged state.
The torque capacity of the clutch depends upon the fluid pressure but the relationship is complicated by several factors. First, there is a time delay between when fluid starts flowing to the cylinder 50 and when the piston 60 has moved far enough to start squeezing the friction plates 44 and separator plates 48 together. The torque capacity of the clutch is nearly zero during this period before the piston 60 is fully stroked. When the piston 60 has moved such that it can apply force to the plates 44 , 48 , the piston and clutch are said to be stroked. Secondly, some amount of pressure, called the stroke pressure, is required to overcome the force of the return spring 62 even after the piston 60 is stroked.
Once the piston 60 is stroked, the clutch torque capacity is proportional to the fluid pressure minus the stroke pressure. However, a variety of unpredictable noise factors influence the relationship between the solenoid 54 current as commanded by the controller 42 and the torque capacity so that the commanded torque capacity may not be accurately achieved. For example, variations in the coefficient of friction, frictional forces between the piston 60 and the cylinder 50 , and pressure variations in the passageway 58 , may cause the actual torque capacity to be either higher or lower than commanded.
These noise factors can make it difficult to achieve a smooth shift behavior without torque transient conditions that may be perceptible to a driver. A downshift from one speed ratio to another requires the coordinated application of one clutch and release of another. For example, to shift from sixth gear to fifth gear, brake 30 (the OGC) is released while clutch 38 (the OCC) is applied, as described in Table 1. As discussed above, noise factors make it more difficult to achieve a smooth shift behavior using only open loop control strategies. The disturbances associated with pressure control inaccuracy are best understood in relation to the intended behavior which is illustrated in FIG. 3 . As discussed below, actual control strategies do not repeatably achieve this behavior.
FIG. 3 illustrates how a downshift process would ideally be executed if there were no noise factors and the controller could command precisely the right amount of torque capacity. The holding pressure for the OGC would be set to the pressure at which the torque capacity of the OGC equals the torque carried by the OGC in the initial gear. To initiate the shift, the controller would reduces the pressure to the OGC to a level slightly below the holding pressure as shown at 102 , marking the beginning of the inertia phase.
During the inertia phase, the input speed would increase to the correct multiple of the output speed for the destination ratio, as shown at 104 . The output torque would drop slightly, as shown at 106 , because some of the input power would be consumed to overcome the inertia of elements connected to the input. During the inertia phase, the OCC would be stroked in preparation for the torque transfer phase. The commanded pressure to the OCC would be elevated to a high pressure, P boost , for a short interval, t boost , to rapidly fill the cylinder with fluid and move the piston to the stroke position, as shown at 108 . Then, the commanded pressure would be maintained at a pressure near the stroke pressure. In FIG. 3 , the actual pressure is shown equal to the stroke pressure at 110 , which would keep the piston stroked but not apply any torque.
Once the input speed reaches the correct multiple of the output speed at 112 , the torque transfer phase begins. During the torque transfer phase, the commanded pressure to the OGC would be gradually reduced 114 while the commanded pressure to the OCC is gradually increased 116 . Ideally, the torque capacity of the two clutches would be coordinated such that the input speed remains constant 118 and the output torque gradually increases 120 . The torque transfer phase is complete when the OCC pressure is above its holding pressure 122 and the OGC pressure is below its stroke pressure 124 . The commanded pressure of the OCC would then be further increased to provide some margin over the holding pressure as shown at 126 .
While FIG. 3 illustrates an ideal system without noise factors, the actual pressure will generally only approximate the stroke pressure. In the absence of a feedback signal, it is difficult to determine if the commanded pressure has being achieved.
FIGS. 4-5 illustrate the potential problems associated with the noise factors and subsequent pressure control errors in an open loop control strategy. FIG. 4 illustrates an effect of accidentally commanding an OCC pressure above the stroke pressure during the inertia phase 128 . Once the OCC is stroked, the torque capacity increases to a positive value 130 . Since the speed ratio at this point is below the speed ratio of the destination gear, torque capacity of the OCC produces a drop in the output torque 132 . The vehicle occupants perceive this fluctuation in output torque as a rough and jerky shift event.
FIG. 5 illustrates an effect of accidentally commanding an OCC pressure below the stroke pressure 134 . In this circumstance, the OCC is not fully stroked by the beginning of the torque transfer phase. As the commanded pressure of the OCC is increased in the torque transfer phase, there is a delay before the OCC torque capacity begins to increase 136 . During this delay period, the input speed continues to increase above the speed ratio of the destination gear as shown at 138 . This is called an engine flare. Eventually, the OCC torque capacity increases enough to bring the input speed back to the desired level 140 . The output torque changes suddenly 142 when the input speed returns to the destination gear speed ratio which occupants perceive as a rough and jerky shift event.
FIG. 6 illustrates a flow chart of a control system for a transmission using closed loop control during a ratio shift. As those of ordinary skill in the art will understand, the functions represented by the flowchart blocks can be performed by software and/or hardware. Also, the functions can be performed in an order or sequence other than that illustrated in FIG. 6 . Similarly, one or more of the steps or functions can be repeatedly performed although not explicitly illustrated. Likewise, one or more of the representative steps of functions illustrated can be omitted in some applications. In one embodiment, the functions illustrated are primarily implemented by software instructions, code, or control logic stored in a computer-readable storage medium and if executed by a microprocessor based computer or controller such as the controller 50 .
FIG. 6 is a flow chart for one embodiment of the present disclosure for using a torque sensor for detecting improper stroke and using closed loop control during a ratio shift. Initially when a ratio shift is requested, the controller raises the OCC pressure to a boost pressure P boost for a boost time t boost in order to quickly move the piston to a substantially stroked position, as represented by blocks 60 and 62 . The boost pressure P boost is a clutch control parameter significantly above the stroke pressure P stroke . For example, the boost pressure can be the maximum available pressure based on limits of the solenoid. The boost time t boost is a clutch control parameter calculated to be long enough to substantially stroke the clutch and short enough that the clutch does not prematurely transmit torque.
Then, the controller commands the OCC to an estimated stroke pressure P stroke —est and waits for a period t test calculated to be long enough for the piston to reach an equilibrium position as represented by blocks 64 and 66 . Both P stroke —est and t test are clutch control parameters. Initial values for all clutch control parameters can be established experimentally based on vehicle testing and can be adjusted adaptively during vehicle operation. In this illustrative example, P stroke —est is adjusted adaptively.
At 68 , the controller records a reference reading τ ref from a torque sensor 40 . The torque sensor can measure the torque on the output shaft as shown in FIG. 1 , the input shaft, or any other element that transmits torque in the destination gear. At 70 , the controller commands a pressure variation P test above or below the estimated stroke pressure P stroke —est . The incremental pressure P test is calculated to be enough of a pressure variation to generate a change in the torque measured by the torque sensor 40 if the clutch is fully stroked. However, the pressure variation can be small enough that the change in torque would not be objectionable or even noticeable to the vehicle occupants.
At 72 , the controller records a second reading τ test from the torque sensor 40 . At 74 , the controller compares the two torque readings, τ ref and τh test , to determine if the difference between τ ref and τ test differ by more than a threshold amount τ threshold . The threshold amount τ threshold is calculated to be large enough that short term variations due to noise factors are not erroneously attributed to the change in commanded pressure. If the two pressures, τ ref and τ test , differ by less than the threshold amount τ threshold , this is indicative that the piston was not fully stroked. If the piston is not fully stroked, then the estimated stroke pressure is increased as represented by block 76 . On the other hand, if the two pressures, τ ref and τ test , differ by more than the threshold amount τ threshold , this is indicative that the piston was fully stroked. If the piston is fully stroked, then the estimated stroke pressure is decreased, as represented by block 78 . At 80 , the controller commands the revised estimated stroke pressure.
Finally, if there is time remaining before the end of the inertia phase, another adjustment is performed. Otherwise, the process ends and the revised estimated stroke pressure is utilized in future shift events involving that OCC.
FIG. 7 illustrates the results of utilizing the control strategy of FIG. 6 when the initial estimated stroke pressure is higher than a required stroke pressure as shown at 144 . When the estimated stroke pressure is too high, the clutch is fully stroked and has positive torque capacity 146 . When the clutch is fully stroked, the upward 148 and downward 150 perturbations in commanded pressure produce measurable changes in torque as shown at 152 and 154 which are detectable by the torque sensor. For example, the upward perturbation 148 results in the measured torque reading τ test1 156 . The torque perturbation is compared to a reference torque value τ ref1 158 . If the difference between the measured torque readings, τ test1 and τ ref1 , is greater than a threshold amount τ threshold , then the estimated stroke pressure is decreased. The controller commands this decreased stroke pressure 160 .
Prior to a second perturbation 150 , a revised reference torque value τ ref2 162 is measured. Following the perturbation, a second torque reading τ test2 164 is measured. Even though the new commanded pressure is below the required stroke pressure, the torque difference still exceeds the threshold, resulting in another downward adjustment. The commanded pressure is set to the new adjusted value as show at 166 . Please note, the perturbations in pressure and torque may be exaggerated for illustrative purposes.
FIG. 8 illustrates the results when the initial estimate of stroke pressure is below the actual stroke pressure as shown at 168 . When the estimated stroke pressure is too low, the clutch is not fully stroked and has zero torque capacity 170 . In this unstroked condition, perturbations in commanded pressure do not produce a measurable change. For example, as illustrated, upward pressure pulse 172 and downward pressure pulse 174 do not affect output torque 176 . Consequently, then the estimated stroke pressure can be increased after each perturbation. The controller commands this increased stroke pressure as shown at 178 and 180 .
FIG. 9 is a flow chart for another embodiment of the present disclosure where the initial estimate of the stroke pressure is intentionally set slightly below the required stroke pressure and gradually increased until a measurable change is detected. Blocks 60 through 68 are identical to the previously described embodiment except that the initial estimate is decreased from the previous value at block 86 . Blocks 88 , 90 , 92 , and 94 form a loop in which the estimated stroke pressure and the commanded pressure is gradually increased until the torque sensor indicates a change in measured torque. The increment added to P stroke —est in each iteration can be small compared to the increment used at blocks 76 and 78 of FIG. 6 or block 86 of FIG. 9 .
FIG. 10 illustrates the results of utilizing the control strategy described in FIG. 9 . After the boost phase, the clutch pressure is set to a value below the stroke pressure at 182 . Because the clutch is not fully stroked, the clutch torque capacity is zero 184 . The reference torque value T ref 186 is measured. Then, the commanded pressure is gradually increased, as shown at 188 . Once the commanded pressure reaches the stroke pressure, the clutch torque capacity will begin to increase above zero, as shown at 190 , and the output torque will begin to decrease, as shown at 192 . In each iteration, a new test torque τ test 194 is measured until the difference between the measured torque readings, τ test and τ ref , is greater than a threshold amount τ threshold 196 .
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
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A transmission and control method are disclosed which ensure proper stroke pressure and minimize torque transients during a shift event. The transmission includes a clutch having a torque capacity based on a fluid pressure, a torque sensor adapted to measure a torque value that varies in relationship to the torque capacity, and a controller. The method includes varying the fluid pressure around a predetermined value, measuring a resulting torque difference with the torque sensor, and adjusting a clutch control parameter if the resulting torque difference is less than a threshold value.
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RELATED APPLICATION
This is a divisional of U.S. patent application Ser. No. 10/814,435 titled “Radial Reflection Diffraction Tomography,” filed Mar. 30, 2004, incorporated herein by reference, which claims the benefit of U.S. Provisional Application No. 60/474,861, titled, “Radial Reflection Diffraction Tomography,” filed May 30, 2003, incorporated herein by reference.
The United States Government has rights in this invention pursuant to Contract No. DE-AC52-07NA27344 between the U.S. Department of Energy and Lawrence Livermore National Security, LLC, for the operation of Lawrence Livermore National Laboratory.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to imaging, and more particularly to an imaging method and apparatus employing Radial Reflection Diffraction Tomography.
2. Description of Related Art
Intravascular ultrasound (IVUS) imaging provides a method for imaging the interior of blood vessel walls. In standard acoustical techniques, a catheter with a rotating ultrasound transducer is inserted into a blood vessel. The transducer launches a pulse and collects the reflected signals from the surrounding tissue. Conventional ultrasonic imaging systems use B-mode tomography or B-scans, wherein images are formed from the envelope of the received display echoes returning to an ultrasonic transducer as brightness levels proportional to the echo amplitude and by assuming straight ray theory (i.e., geometrical optics). The brightness levels can then be used to create cross-sectional images of the object in the plane perpendicular to the transducer image. However, such images typically suffer from the consequences of ray theory of sound propagation, which does not model its wave nature.
A circumferential scan can be made by either rotating a single transducer (mechanical beam steering) or by phasing an array of transducers around a circumference (electronic beam forming). Typically, one ultrasound pulse is transmitted and all echoes from the surface to the deepest range are recorded before the ultrasound beam moves on to the next scan line position where pulse transmission and echo recording are repeated. When utilizing B-scan, the vertical position, which provides depth of each bright dot is determined by the time delay from pulse transmission to return of the corresponding echo, and the horizontal position by the location of the receiving transducer element.
Although B-scan IVUS images can be utilized to detect plaque and characterize its volume, the classification of plaque types by ultrasound is very difficult. Conventional B-scan images utilizes scattering, which, in turn, depends on the acoustic impedance dissimilarity of tissue types and structures. Although hard calcifications in some plaque can be detected using such a mismatch, the similarity in the acoustic properties of fibrous plaque and lipid pools prevents direct identification. Consequently, the size of the fibrous cap cannot be accurately estimated.
Diffraction tomography has additionally been applied to medical imaging problems for a number of years, usually in a standard circumferential through transmission mode. Furthermore, improved vascular images have been provided by utilizing time domain diffraction tomography, a technique capable of accounting for the wave propagation of the transmitted acoustic waves in addition to redundant information from multiple angular views of the objects imaged. A related B-mode approach that incorporates spatial compounding has also been employed to provide improved vascular images through multiple look angles.
Background information on rotational IVUS systems are described, for example, in U.S. Pat. No. 6,221,015 to Yock. Background information on phased-array IVUS systems are described, for example, in U.S. Pat. No. 6,283,920 to Eberle et al., as well as U.S. Pat. No. 6,283,921 to Nix et al. Multi-functional devices have been proposed in other areas of vascular intervention. For example, U.S. Pat. No. 5,906,580 to Kline-Schoder et al., describes an ultrasound transducer array that may transmit signals at multiple frequencies and may be used for both ultrasound imaging and ultrasound therapy. Therapeutic ultrasound catheters, are described, for example, in U.S. Pat. No. 5,725,494 to Brisken et al. and U.S. Pat. No. 5,581,144 to Cori et al., which describes another ultrasound transducer array that is capable of operating at multiple frequencies. However, none of the above devices and associated techniques from the above cited patents, are suited for rapid identification of objects, such as, but not limited to, vulnerable plaque or objects recessed in a bore hole, in accordance with the principles of the present invention.
SUMMARY OF THE INVENTION
The present invention is directed to a wave-based imaging method, which includes: directing predetermined energy waves radially outward from within an interspace and receiving scattered energy waves from one or more objects. The received data are processed to produce images of the objects, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves to construct images of the one or more objects.
Another aspect of the present invention is directed to a wave-based imaging method that can be utilized to characterize a plaque, which includes: inserting a catheter having a longitudinal axis and a distal end into an artery, wherein the catheter further includes a single transmitter disposed about the distal end of the catheter and a receiver aperture having a plurality of receivers additionally disposed about the distal end of the catheter, wherein the transmitter and the receiver aperture is capable of rotating up to 360 degrees about the longitudinal axis of the catheter. As part of the method, one or more predetermined energy waves are directed radially outward from the single transmitter and radial scattered energy waves are received in a predetermined imaging mode by the receiver aperture. The received scattered energy waves results in collected data capable of being processed to produce images of plaque from the surrounding artery walls, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves to construct the images and determine the risk of rupture and/or thrombosis.
Another aspect of the present invention is directed to a wave-based imaging method that can be utilized to characterize a plaque, which includes: inserting a catheter into an artery, directing one or more predetermined energy waves radially outward and receiving one or more radial scattered energy waves from a distal end of the catheter; collecting a radial scattered tomographic data baseline of the artery's tissue; measuring an applied external pressure to the artery; obtaining a deformation radial scattered tomographic data set of the artery's tissue after application of the external pressure; and processing the radial scattered tomographic data baseline and the deformation radial scattered tomographic data set to produce a final image indicating elasticity of the artery to characterize the imaged plaque, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves.
A further aspect of the present invention is directed to a wave-based imaging apparatus, which includes a flexible substrate having a longitudinal axis and a distal region and one or more elements disposed on the distal region and capable of directing one or more predetermined energy waves radially outward and receiving one or more radial scattered energy waves from one or more objects. The received scattered energy waves are capable of producing images of one or more objects by processing a collected data set, wherein the processing includes application of a wave-based algorithm that can map an angular location and a plurality of frequency parameters of the received scattered energy waves.
A final aspect of the present invention is directed to a wave-based imaging apparatus that includes a Hilbert space inverse wave (HSIW) algorithm that can map an angular location and a plurality of frequency parameters of said received reflected diffracted energy waves so as to characterize plaque within a living vessel.
Accordingly, the present system and method employs desired Radial Reflection Diffraction Tomographic techniques to determine the state and location of buried wastes, to track plumes of underground contaminants of materials, to determine the state of materials residing in waste drum barrels or weapons, to evaluate nondestructively parts having existing access holes (e.g., automobile parts), and for identifying potentially life threatening vulnerable plaque buildup on living vessel walls.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a basic multimonostatic mode configuration that includes a single transducer rotating about a fixed center.
FIG. 1B illustrates a basic multistatic mode configuration that includes a fixed annular array of outwardly directed transducers.
FIG. 1C illustrates a basic multistatic mode configuration that includes a rotating aperture.
FIG. 2 shows a conventional IVUS catheter.
FIG. 3A shows a conventional IVUS catheter inserted into a diseased artery,
FIG. 3B illustrates the RRDT geometry of the present invention when a catheter is inserted into a diseased artery.
FIG. 4 illustrates RRDT non-destructive evaluation within a bore hole.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the following detailed information, and to incorporated materials; a detailed description of the invention, including specific embodiments, is presented.
Unless otherwise indicated, numbers expressing quantities of ingredients, constituents, reaction conditions and so forth used in the specification and claims are to be understood as being modified 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 subject matter presented herein. 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 subject matter presented herein 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.
General Description
The present invention employs inverse wave techniques to reconstruct images of a medium surrounding a physical probe in a plane perpendicular to an axis of rotation in a radial reflection configuration, i.e., in a multimonostatic or a multistatic arrangement disclosed infra, wherein one or more transmitting and receiving elements, more often at least about 15 of such elements, e.g., transducer(s), are at a fixed radius and designed to collect scattered fields, e.g., reflected and diffracted fields. Such a radial reflection diffraction tomography (RRDT) technique is based upon a linearized scattering model to form images given the disclosed physical transmitter and receiver configurations and the mathematical method, i.e., a Hilbert-based wave algorithm, utilized to invert the scattering collected fields.
As example embodiments, the multimonostatic and multistatic probes can be mounted at the end of a flexible substrate, such as a catheter or snaking tube that can be inserted into a part with an existing access hole or a medium (e.g., an artery) with the purpose of forming images of the plane perpendicular to the axis of rotation. By applying the Hilbert space inverse wave (HSIW) algorithm of the present invention to the collected data of such multimonostatic and multistatic probes, radial reflected diffraction tomographic images are readily obtained.
Specific Description
FIG. 1A shows a basic multimonostatic conceptual arrangement of the present invention, wherein a single energy source element 1 , such as a transducer, can operate as both source and receiver (as denoted by T/R, to indicate transmitter and receiver) at multiple spatial locations. At each angular location along the illustrated dashed circumference, as denoted by the directional arrow, energy source element 1 can launch a primary field wave (not shown) and receive a reflected scattered field wave (not shown). Such an arrangement often requires a spectrally wide band frequency diverse source capable of producing frequencies from about 1 kHz to about 3 THz (Electromagnetic frequencies), often from about 100 Hz to about 10 GHz (Acoustic frequencies), more often between about 20 MHz and about 60-MHz (Acoustic frequencies), to provide spatial diversity so as to form images of a surrounding medium.
FIG. 1B shows an example conceptual multistatic mode embodiment, wherein a plurality of fixed energy source elements 2 , e.g., transducers, are arranged as an annular array, generally designated by the reference numeral 20 . In succession, along for example, the illustrated directional arrow, each energy source element (for example, the element denoted by the letter T to indicate a transmitter) is capable of launching a primary field wave (not shown) and a backscattered field wave (not shown) is measured on all the remaining elements (as denoted by the letter R, indicating the remaining fixed elements are operating as receivers).
FIG. 1C illustrates a beneficial multistatic conceptual arrangement that includes a plurality of energy source elements 4 configured in a rotating sub-aperture 6 , as denoted by the bi-directional arrow, formed by a single transmitter, as denoted by the letter T to indicate a transmitter, and surrounded by multiple receivers, as denoted by the letter R. At each angular location, as denoted by the single directional arrow along the illustrated dashed circumference, transmitter T can launch a primary field (not shown) and a backscattered field (not shown) is measured on all receivers R.
When operating in a reflection mode as disclosed herein, the mathematics applied to the collected data operate beneficially to image objects because the range resolution of the reconstructed image is proportional to the number of frequencies used in the reconstruction. Under the Hilbert space inverse wave algorithm, increasing the number of frequencies and transducers, increases the complexity of the reconstruction, the size of the intermediary data files, reconstruction time, and computer memory requirement. Thus, the trade-off between computer resources and resolution is a consideration. Nonetheless, the techniques employed in the present invention are beneficial even at acoustic frequencies from as low as about 100 Hz to as high as about 10 GHz. Such lower frequencies allow the disclosed embodiments to additionally be employed in borehole type of applications, such as, but not limited to, characterizing underground contamination plumes or waste in contamination barrels.
For either the multimonostatic or multistatic example embodiments, the planar reconstruction of the imaged object(s) requires that the one or more collected measurements map a pair of spatial variables (i.e., angular location and incident source frequency) of a physical object into the angular location and frequency parameters of the measured field.
An exemplary application of the present invention is in the characterization of vulnerable atherosclerotic plaque. Arthrosclerosis is a condition where the arteries are obstructed by the buildup of deposits, “intravascular plaque” (IVP), on the inside of arterial walls and such a buildup of deposits can lead to what is known to those of ordinary skill in the art as cerebrovascular disease, which is the third leading cause of death and the leading cause of major disability among adults. Plaque grows as a fibrous tissue encapsulating a lipid pool and as the plaque grow it may incorporate calcium. Of particular concern is vulnerable or unstable plaque because of the possibility of such plaque becoming inflamed and unexpectedly rupturing. Stable or non-vulnerable plaque, typically includes a thick layer of fibrous tissue of about 800 microns but is not life threatening and can be treated slowly. A thin fibrous cap of typically up to about 300 microns covering a pool of a soft lipid core typically characterizes vulnerable plaque. When such a cap is disrupted, the thin cap is compromised and the lipid deposited into the artery can produce adverse effects, such as thrombus formation, strokes and death.
FIG. 2 shows a conventional catheter, generally designated as reference numeral 200 , for intravascular tissue characterization, such as atherosclerotic vulnerable plaque. Such a catheter 200 , typically has an elongated flexible substrate 202 with an axially extending lumen 204 through which a guide wire 206 , and/or various other devices or other instruments can be delivered to a region of interest. An ultrasonic transducer assembly 208 is provided at the distal end 210 of the catheter, with a connector 214 located at the proximal end of the catheter for transducer manipulation and processing received transducer signals. Transducer assembly 208 can comprise a plurality of transducer elements 216 arranged in a cylindrical array centered about a longitudinal axis 218 of the catheter for transmitting and receiving ultrasonic energy. Adhesive (not shown) and or an end-cap (not shown) can be applied to transducer assembly 208 , and lumen 204 to protect such elements from the surrounding environment Transducer assembly's 208 individual elements (not shown) and conductive acoustical backing (not shown) are often mounted on the inner wall of elongated flexible body 202 operating as the flexible substrate.
FIG. 3A illustrates a typical IVUS method using such a catheter 200 , as shown in FIG. 2A . In such a conventional application, catheter 200 , having a transducer assembly 208 that can launch an energy wave as a primary field (as denoted by the letter F) is inserted typically non-centered into a nominally circular diseased artery 302 . Around a wall 304 of artery 302 is a fibrous collagen plaque 306 . A lipid pool 308 can reside inside such a fibrous structure, wherein when a fibrous cap 310 of plaque 306 separating lipid pool 302 from the blood (not shown) within artery 302 is more than about 800 μm thick, plaque 306 is characterized as stable. However, in cases where cap 310 is less than about 300 μm thick, such a plaque is characterized as vulnerable, and is more likely to rupture and/or thrombosis.
The present invention utilizes the disclosed RRDT approach for improved intravascular applications such as characterizing plaque as discussed above, and incorporates various aspects of the method of utilizing a probe, such as, but not limited to, the catheter as shown in FIG. 3A . However, such catheters 200 and similar probes known to those of ordinary skill in the art typically show angular overlap for beam processing, which results in loss of valuable image information of one or more objects of interest within a surrounding medium. The present invention overcomes such processing by incorporating novel improvements of the transmitters and receivers, by utilizing frequencies between about 20 MHz (Acoustic) and about 60 MHz (Acoustic), and by utilizing RRDT techniques of the present invention as discussed herein. Such novel embodiments accounts for phase, amplitude, and beam diffraction, to recover not only such loss of valuable image information information but to further enhance the imaging capabilities of the invention by providing images with improved lateral resolution of the acoustic absorption and sound speed.
FIG. 3B shows the geometry incorporated by the RRDT method of the present invention. FIG. 3B shows a cross-sectional view of a catheter 200 , having an outer diameter between about 0.25 mm and about 5 mm, being inserted into an artery 302 , having a surrounding plaque 306 that includes a cap 310 and a lipid pool 308 . Inserted into artery 302 is a non-centered catheter 200 , which includes a transducer assembly (not shown) that can be disposed about the distal end of catheter 200 , as disclosed in the present invention, with a radial location specified by r o ≡R o (cos θ o , sin θ o ), where R o , is the catheter 200 probe radius, a constant. At each angular location, θ o , transducer assembly 208 , as shown in FIG. 3A , launches a primary field F radially outward (as denoted by the letter r) into a medium, such as the blood (not shown) and surrounding tissue in this example, and the transducer arrangement, as disclosed in the present invention, can measure a reflected scattered field (not shown) having, for example, at least up to about 90 degrees of angular content from one or more objects, such as the linings of cap 310 that overlies lipid pool 308 .
As another example embodiment, the RRDT method and apparatus of the present invention can be combined with elastography to gain further insight into a surrounding medium's elastic properties and provide further information in the determination of characterizing plaque as vulnerable or stable. Generally, the contrast in elastic properties between a lipid pool and a fibrous cap is evident. By utilizing elastography, the elastic properties of a vessel wall can be obtained by observing a deformation of the vessel due to an external pressure, such as the pressure produced by a heart. Such a change in the arterial pressure due to the pumping action of the heart produces a measurable deformation of the tissue surrounding the vessel. Such a deformation can be measured by tracking a motion of patterns in successive intravascular scans as disclosed by the present invention. By knowing the arterial pressure and the measured deformation, the present invention can recover elastic properties of the surrounding tissue. From such elastic properties, one can further characterize the surrounding tissue to predict plaque composition.
FIG. 4 illustrates a further beneficial embodiment, wherein the present invention can be utilized for non-destructive characterization (i.e., RRDT imaging) in applications other than for intravascular RRDT imaging. As shown by the example cross-sectional underground view of a borehole 404 in FIG. 4 , a flexible substrate 400 or snake-like tube having a transducer assembly 402 similarly configured like the intravascular RRDT application discussed above, can be lowered into bore hole 404 so as to image a site using RRDT techniques. Such an arrangement can launch a primary field (denoted by the letter F) and receive diffracted energy waves having frequencies often between about 100 Hz and about 300 Hz, to determine the state of buried wastes, such as waste within a radioactive waste drum barrel 410 or a biohazardous container, and/or to track a plume 412 of underground contaminants. In a similar manner, disclosed probes herein, can be inserted into waste drum barrels 410 , or weapons (not shown) or any part having an existing access hole, such as, but not limited to, an automobile engine, and determine the state of the part or material.
Hilbert Space Wave Inversion
Hilbert spaces are spaces constructed using vectors. Specifically they define vector spaces where sets of vectors in the space “add up” to another vector, an analog to Euclidean space where measurements can be added to result in another valid measurement. Hilbert spaces are particularly useful when studying the Fourier expansion of a particular function. In the Fourier transform, a complex function describing a waveform is re-expressed (transformed) into the sum of many simpler wave functions. A Hilbert space describes the “universe of possible solutions” given one particular such function. The Hilbert space inverse wave (HSIW) algorithm of the present invention enables an inverse for any multistatic or multimonostatic geometry with any combination of sources, receivers, and frequencies.
In a radial reflection device of the present invention, such as an intravascular ultrasound probe having an outer diameter between about 0.25 mm and about 5 mm, or a probe configured to non-destructively characterize buried wastes (e.g., tracking plumes of underground contaminants of materials), evaluating the state of materials residing in waste drum barrels or weapons, or to nondestructively evaluate parts with existing access holes (e.g., automobile parts), acquired data are collected at discrete angular locations. Such angular locations are denoted by:
R n t ≡R 0 (cos θ n ,sin θ n ) (1)
for transmitter locations, where θ n =nΔθ src for n=0, 1 . . . , N src −1, where N src 2π/Δθ, and Δθ src is the source angular increment.
Similarly, receiver locations are given by:
R m r ≡R o (cos θ m ,sin θ m ) (2)
where θ m =mΔθ rcv for m=0, 1 . . . , N src −1, where N rcv 2π/Δθ rcv , and Δθ rcv is the receiver angular increment.
For each source, configured receiver(s) can record a backscattered field as a time series that can be digitized for processing. Discrete Fourier transforming the time series data result in the spectrum of one or more measured wave forms at discrete frequencies. The forward scattering equation under the Born approximation with both spatial and frequency diversity is given by:
ψ B scat ( R m r ,R n t ,ω l )= P (ω l ) k O 2 (ω l )∫ dr′G ( R m ′,r′,ω l ) o ( r′ ) G ( r′,R u t ,ω l ) (3)
where ω l , l=0, 1, . . . , N f −1 are the discrete frequencies and N f is the number of frequencies in the pulse band width.
The HSIW as disclosed herein interprets Equation (3) as a mapping from a continuous object space to a discrete measurement space. The object space is the physical (x,y) space of the object function. The measurement space includes discrete angles and temporal frequencies at which the scattered data are collected. The scattering operator projects the object onto the measurement space. The forward propagation or projection kernel is defined as:
Π*( r )≡ P (ω l ) k O 2 (ω l ) G ( R m r ,r,ω l ) G ( r,R n t ,ω l ), (4)
where Π(r) is a J≡(N src ×N rcv ×N f ) element column vector, and P(ω l ) is the incident pulse spectrum. Mathematically, the projection is represented as an inner product between the object function and the kernel via:
D=∫dr Π*( r ) o ( r )≡ Π, o (5)
where D is a J element column vector, and where each element represents a particular source, receiver, and frequency combination. Symbolically, the forward scattering operator, K, is defined as:
K[•]≡∫dr Π*( r )[•]. (6)
The HSIW method of the present invention is employed to derive an inverse of the operator as shown in equation (6). The singular value decomposition (SVD) of K is given as:
K=USV † , (7)
where the columns of U form an orthonormal set of column vectors, u j , which span a measured data space, and the components of V form an orthonormal set of vectors, v j (r), which span an object space. S is a diagonal matrix of singular values, σ j . It is emphasized that the u j are complex column vectors where as the v j (r) are complex functions of r. The set of normal equations for such a singular system are:
Kv j ( r )=σ j u j , (8)
K † u j =σ j v j ( r ), (9)
KK † u j =σ j Kv j ( r )=σ j 2 u j , (10)
K † Kv j ( r )=σ j K † u j ( r )=σ j 2 v j ( r ), (11)
The inversion method of the present invention estimates the object function of equation (5) given measured data in D. Such an inversion incorporates expanding the object function in terms of v j (r):
o ^ ( r ) = ∑ j = 0 J - 1 α j v j ( r ) , ( 12 )
where the α j are constant coefficients to be determined. Substituting the object expansion into equation (5) results in:
D
=
∫
ⅆ
r
Π
*
(
r
)
∑
j
=
0
J
-
1
α
j
v
j
(
r
)
=
∑
j
=
0
J
-
1
α
j
∫
ⅆ
r
Π
*
(
r
)
v
j
(
r
)
,
(
13
)
Applying the definition of the K operator in equation (6) to equation (8) yields an expression for the integral of equation (13),
Kv j =∫dr Π*( r ) v j ( r )=σ j u j , (14)
which reduces equation (13) to:
D
=
∫
∑
j
=
0
J
-
1
α
j
σ
j
u
j
,
(
15
)
Using the orthogonality of the u j vectors, the unknown α j is solved as follows:
u i † D = ∑ j = 0 J - 1 α j σ j u i † u j = ∑ j = 0 J - 1 α j σ j δ ij = α i σ i , ( 16 )
resulting in:
α
i
=
u
i
†
D
σ
i
,
(
17
)
The adjoint of the forward scattering operator, K † and the singular values and singular vectors, σ j , u j , and v j (r) are now required. First, the following inner product equation defines the adjoint,
u,Kv = K † u,v (18),
Using the definition of the forward scattering operator from equation (16) results in:
u † ∫dr Π*( r ) v ( r )=∫ dr ( u † Π*( r )) v ( r ), (19)
By comparing the right hand sides of equations (18) and (19), the following definition of the adjoint of the forward scattering operator is obtained:
K † [•]≡[•]·Π r ( r ). (20)
The σ j and u j are determined by solving the eigenvalue equation of equation (10) formed by the outer product of the forward scattering operator with its adjoint. Explicitly, the outer product is represented by:
(∫ dr Π*( r )Π r ( r )) u j =σ j 2 u j , (21)
which is a J×J eigenvalue equation of the form Ax=λx. The Π(r) vectors are known analytically and can be evaluated numerically. It follows that the elements of the outer product matrix can be computed numerically and the resulting system solved numerically for the σ j 2 and u j . Given these and using equation (19) to solve for v j (r) results in:
v
j
(
r
)
=
1
σ
j
Π
T
(
r
)
u
j
.
(
22
)
Substituting equations (17) and (22) into equation (12) yields the final expression for the reconstruction:
o
^
(
r
)
=
∑
j
=
0
J
-
1
1
σ
j
2
Π
r
(
r
)
u
j
u
j
†
D
.
(
23
)
As described above, the Π(r) vectors of equation (4), and outer products and eigenvalues of equation (21) are computed numerically. The measurement system of the analytically described invention only measures part of the scattered field due to the aperture and the loss of the evanescent field information and accordingly, some of the eigenvalues, σ j 2 , are close to zero. Those eigenvalues and their corresponding eigenvectors determine the rank of the outer product matrix, and they must not be used in the reconstruction of equation (23). Thus, in the method of the present invention, a Best Rank N approximation is used to select the number of singular values/vectors. A ratio is computed as follows:
R ( N ) = ∑ j = 0 N - 1 σ j 2 ∑ j = 0 J - 1 σ j 2 , ( 24 )
where the singular values are assumedly arranged from smallest to largest: σ 0 2 ≦σ 1 2 ≦σ J-1 2 . Plotting R(N), the point at which the function starts to rise rapidly is graphically identified. The index of the singular value at which this occurs is labeled as J 0 . With this value determined, a final reconstruction is as follows:
o
^
(
r
)
=
∑
j
=
J
o
J
-
1
1
σ
j
2
Π
T
(
r
)
u
j
u
j
†
D
(
25
)
The HSIW as disclosed herein is flexible in that it allows any transducer configurations of the present invention and any number of frequencies to be used in forming such a final reconstruction.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the claims.
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A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a “pitch/catch” operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a valve for regulating the pressure of vapor or liquid which incorporates the ability or relieving pressure if it exceeds the regulated level by a predetermined amount.
2. Description of the Prior Art
In various fluid supply systems, it is often necessary to regulate the pressure level of a fluid and, at the same, to relieve pressure if the pressure of the fluid on the regulated side or the unregulated side of the valve exceeds a predetermined amount.
For example, in cryogenic supply systems for oxygen, nitrogen, and the like, gas is supplied to a pressure building regulator value from a pressure building coil connected to the bottom of the cryogenic liquid tank, which supplies the gas at a regulated pressure to the top of the tank. The gas in the tank, at the pressure level regulated by the pressure building regulator valve, forces the liquid out of the tank of the desired pressure through a liquid supply line. Because the tank pressure may increase above the regulated level due to evaporation of the cryogenic liquid in the tank, a second regulating valve must be used. This second regulating valve is sometimes known as an "economizer" regulator, since it permits the gas to flow from the tank to the gas supply line or to a vent line. In addition, it is possible that the level of the gas pressure in the pressure building coil may be too high to permit the gas to be supplied to the tank. In this case, a third valve must be used to relieve excess pressure in the pressure building coil.
Thus, it can be seen that three valves may be needed. A first valve to regulate pressure from the pressure building coil to the tank top. A second valve to relieve excess pressure in the tank top. And, a third valve to relieve excess pressure in the pressure building coil.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of prior art and provides other advantages heretofore not obtainable. The valve of the present invention provides in a single valve the functions of three valves of the prior. It regulates fluid pressure from the inlet side (which may be connected to a pressure building coil) to an outlet side (which may be connected to a tank top); it relieves pressure from the outlet side; and it relieves pressure from the inlet side. The valve of the present innvention thus provides a pressure regulating function whereby the outlet side of the valve provides fluid at a constantly regulated pressure which is below the pressure of the fluid supplied on the inlet side of the valve. In addition, the valve of the present invention provides pressure relief capabilities on both the inlet and outlet side of the valve whereby pressure is relieved from either side of the valve if it exceeds the limit by a predetermined amount. The relief pressure may be provided to a pressure relief line attached to a third port on the valve.
These functions are performed by the valve in the present invention in an efficient manner with the pressures being regulated and relieved accurately. In addition, the valve is adjustable so that the regulating level may be changed, and the relief level may be changed with respect to the regulating level. The valve which performs all of these functions may be produced economically because it has relatively few parts which can be easily assembled.
These and other advantages are achieved by the valve of the present invention for supplying fluid of a rate between 20 and 1,000 standard cubic feet per hour. The valve comprises a body having a first fluid passage, a second fluid passage communicating with the first fluid passage, a pressure relief passage communicating with the first and second fluid passages, and an ambient chamber vented to the ambient pressure. The valve also comprises a compressible bellows located in the first fluid passage. The bellows is capable of sealing the first fluid passage from the second fluid passage and is also capable of sealing the first fluid passage from the pressure relief passage. The valve also comprises a diaphragm separating the second fluid passage and the ambient chamber. The valve also comprises a connecting member located in the second fluid passage adjacent to the first vapor passage and attached to the diaphragm. The connecting member is capable of engaging the bellows to seal the second fluid passage from the pressure relief passage. The valve also comprises adjustable spring means biasing the diaphragm to urge the connecting member into sealing engagement with the bellows.
Preferably, the fluid inlet of the valve is connected to the first vapor passage and the fluid outlet is connected to second vapor passage. When the pressure in the outlet side of the valve decreases, the action of the spring means against the diaphragm thus forces the connecting member to compress the bellows opening the passage between the first fluid passage and the second fluid passage. When the pressure on the outlet side of the valve exceeds a predetermined limit, the pressure in the second fluid passage increases moving the diaphragm in opposition to the spring means and pulling the connecting member which is attached to the diaphragm away from the bellows to permit fluid from the second fluid passage to flow into the pressure relief passage. When pressure on the inlet side of the valve exceeds a predetermined limit, the pressure in the first fluid passage increases, compressing the bellows and permitting fluid from the first fluid passage to flow into the pressure relief passage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view of the valve of the present invention showing the valve in an equilibrium condition in which the first fluid passage, the second fluid passage, and the pressure relief passage are all sealed with respect to each other;
FIG. 2 is a side sectional view of the valve similar to FIG. 1 showing the action of the valve when the pressure in the second fluid passage decreases below a predetermined limit allowing fluid from the first fluid passage to flow into the second fluid passage;
FIG. 3 is side sectional view of the valve of FIGS. 1 and 2 showing the action of the valve when the pressure in the second fluid passage increases above a predetermined limit, allowing fluid from the second fluid passage to flow into the pressure relief passage; and
FIG. 4 is a side sectional view similar to FIGS. 1-3 showing the action of the valve in which pressure in the first vapor passage increases above the design limits of the bellows, allowing fluid from the first fluid passage to flow into the pressure relief passage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1 there is shown the valve 10 of the present invention. The valve 10 has a body 11 consisting of a main body member 12, a relief connecting body member 13, and a spring containing body member 14. The body member 13 is connected to the main body member 12 by a threaded connection 15, and the body member 14 is connected to the main body member 12 by a threaded connection 16.
The valve 10 has a fluid inlet 18 having an internal thread for connection to a conduit. The valve 10 also has a fluid outlet 19 having an internal thread for connection to a conduit. The valve 10 also has a pressure relief line connection 20 formed in the body member 13 and having an internal thread for connection to a relief line.
The fluid inlet 18 is connected to a first fluid passage 22 formed in the valve body 11. The fluid outlet 19 is connected to a second fluid passage 23 which is also formed in the valve body 11. The first fluid passage 22 is separated from the second fluid passage 23 by a wall 24 and a wall 25. The walls 24 and 25 are both formed as part of the valve body 11. An opening 26 is provided in the wall 25 so that the first fluid passage 22 may communicate with the second fluid passage 23.
The pressure relief line connection 20 is connected to a pressure relief passage 28. The pressure relief passage 28 is connected to a slotted tube 29 which extends through the first vapor passage 22, through the opening 26, and into the second fluid passage 23. The slot in the tube 29 permits fluid in either the first fluid passage 22 or the second fluid passage 23 to enter the tube 29 and flow into the pressure relief passage 28.
A compressible bellows 31 is mounted in the first fluid passage 22 around the slotted tube 29. The bellows 31 extends from the opening 26 to the connection between the pressure relief passage 28 and the first fluid passage 22. The bellows 31 includes sealing members 32 and 33 on each end of the bellows. The sealing member 32 is capable of sealingly engaging the wall 25 around the opening 26 to seal the first fluid passage 22 with respect to the second fluid passage 23 and prevent fluid from flowing between the passages 22 and 23. The sealing member 33 is capable of sealingly engaging the portion of the body member 13 adjacent to the relief passage 28 to prevent fluid from flowing from the first fluid passage 22 into the relief passage 28.
The bellows 31 normally has a design pressure differential of approximately 30 psi, so that a pressure differential of 30 psi is required between the pressure of the fluid in the first fluid passage 22 and the pressure of the fluid in the relief passage 28 before the bellows will compress to unseal the sealing member to permit pressure relief.
A pair of conical screens 35 and 36 are used to filter the fluid entering the valve to prevent contamination. The screen 35 is positioned at the fluid inlet 18, and the screen 36 is positioned at the fluid outlet 19.
The body member 14 is hollow forming an ambient chamber 38 which is vented to the exterior of the valve. The ambient chamber 38 is separated from the second fluid passage 23 by a diaphragm 39. The periphery of the diaphragm 39 is held in place between a retaining ring 40 and the side of the main body member 12. The retaining ring 40 is captured by the body member 14 which is attached to the main body member 12 at the threaded connection 16. The diaphragm 39 has a central opening in which is mounted a connecting member 42. The connecting member 42 has a larger diameter portion within the second fluid passage 23 which abuts the diaphragm 39. The connecting member 42 is held in contact with the diaphragm 39 by a cap 43. The cap 43 has a central opening which engages the portion of the connecting member 42 extending into the ambient chamber 38 so that the connecting member 42 is held in engagement with the center of the diaphragm 39. The end of the connecting member 42 extending into the second fluid passage 23 has a central bore into which the end of the slotted tube 29 extends. The end of the connecting member 42 which extends into the second fluid passage 23 is capable of extending into the opening 26 and engaging the sealing member 32 of the bellows 31. When the connecting member 42 engages the sealing member 32 of the bellows 31, it prevents fluid from flowing from the second fluid passage 23 into the slotted tube 29 and into the relief passage 28.
The connecting member 42 is formed with peripheral slots or flutes which permit fluid to flow around the connecting member and through the opening 26 when the sealing member 32 of the bellows 31 is out of engagement with either the connecting member 42 or the wall 25.
The diaphragm 39 is biased toward the second fluid passage 23 by a spring 46 engaging the cap 43 which is connected to the connecting member 42. The force of the spring 46 is adjustable by means of an adjusting screw 47 mounted in the end of the body member 14 of the valve body 11. The end of the adjusting screw 47 engages a retaining cup 48. The spring 46 extends between the retaining cup 48 and the cap 43.
The operation of the valve of the present invention can be seen by comparing FIGS. 1-4.
In FIG. 1, the valve 10 is in a equilibrium condition. The fluid pressure at the fluid outlet 19 is at the desired controlled level with respect to the ambient pressure. This controlled fluid pressure level is set by means of the adjusting screw 47. The adjustable force of the spring 46 balances the pressure differential between the pressure of the fluid in the second fluid passage 23 and the ambient pressure in the ambient chamber 38, so that the diaphragm 39 remains in the equilibrium position shown in FIG. 1 with the connecting member 42 engaging the sealing member 32 of the bellows 31, and the sealing member 32 of the bellows 31 engaging the wall 25. Thus, the second fluid chamber 23 is effectively sealed from the first fluid chamber 22 and from the slotted tube 29 connected to the relief passage 29. In addition, the pressure of the fluid at the inlet 18 does not exceed the fluid pressure at the outlet 19 or in the relief tube connection 20 by more than the design compression level of the bellows 31, so that the bellows 31 is not compressed. The bellows 31 is fully extended with the sealing member 32 engaging the wall 25 and the sealing member 33 engaging the body member 13 to seal the first fluid passage 22 from both the second fluid passage 23 and the relief passage 28.
When the pressure at the fluid outlet 19 decreases, the valve 10 reacts as shown in FIG. 2. When the pressure of the fluid at the outlet 19 drops below a predetermined level with respect to the ambient pressure, the spring 47 forces the diaphragm 39 downwardly as shown in FIG. 2. The connecting member 42 is pushed downwardly by the downward movement of the diaphragm 39. Since the connecting member 42 engages the sealing member 32 of the bellows 31, the bellows 31 is compressed, allowing the sealing member 32 to disengage from the wall 25. This permits fluid to flow from the first fluid passage 22 through the opening 26, through the peripheral slots or flutes in the connecting member 42, and into the second fluid passage 23. As fluid flows from the inlet 18 to the outlet 19, the pressure at the outlet 19 increases returning the diaphragm 39 upwardly as shown in FIG. 2 and returning the valve to the equilibrium condition as shown in FIG. 1.
When the pressure at the fluid outlet 19 increases above the desired level, the valve reacts as shown in FIG. 3. The increased pressure in the second fluid passage 23 causes the diaphragm 39 to move upwardly as shown in FIG. 3. The connecting member 42 which is attached to the diaphragm 39 is pulled upwardly and disengages from the sealing member 32 of the bellows 31. This permits fluid to flow from the second fluid chamber 23 around the connecting member 42 and through the peripheral slots or flutes in the connecting member, and into the slotted tube 29 which is connected to the relief passage 28. The fluid is relieved from the fluid outlet 19 and the second fluid passage 23 through the relief passage 28 until the fluid pressure at the outlet 19 returns to the proper level, at which time the diaphragm 39 moves downwardly as shown in FIG. 3 and returns to the equilibrium level as shown in FIG. 1.
When the fluid pressure at the inlet 18 exceeds a predetermined level, the valve 10 reacts as shown in FIG. 4. The increased pressure in the first fluid passage 22 causes the bellows 31 to compress allowing the second sealing member 33 to disengage from the body member 13. This will occur when the pressure in the first fluid passage 22 exceeds the pressure in the relief passage 28 by the pressure differential designed in the bellows 31. Typically, the bellows 31 will compress when the pressure differential is 15 psi. This permits fluid in the first fluid passage 22 to flow into the relief passage 28. Fluid continues to flow from the first fluid passage 22 into the relief passage 28 until the fluid pressure at the fluid inlet 18 returns to the proper level, at which time the bellows 31 expands and the valve returns to the equilibrium condition as shown in FIG. 1.
While the invention has been shown and described with respect to a particular embodiment thereof, this is for the purpose of illustration rather than limitation, and other variations and modifications of the specific embodiment herein shown and described will be apparent to those skilled in the art all within the intended spirit and scope of the invention. Accordingly, the patent is not to be limited in scope and effect to the specific embodiment herein shown and described nor in any other way that is inconsistent with the extent to which the progress in the art has been advanced by the invention.
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A combination pressure regulating valve and pressure relief valve is disclosed in which the outlet pressure is regulated to a certain pressure level below the inlet level and excess pressures on either the inlet or outlet of the valve are relieved through a relief passage. The valve includes a diaphragm biased by an adjustable spring means and a compressible bellows which interact with each to perform both the regulating and relief functions.
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CROSS-REFERENCE TO RELATED APPLICATION
FIELD OF THE INVENTION
[0001] The present invention relates to electronic medical records systems and, in particular, to a data entry system for physicians and other medical professionals providing improved workflow in clinical observations.
BACKGROUND OF THE INVENTION
[0002] Considerable effort has been invested in improving the workflow of physicians to better leverage their skills. Much of this effort has been directed toward implementing electronic medical records to improve physician access to and sharing of medical data.
[0003] The value of electronic medical records can be further enhanced by reducing the burdens placed on physicians for data entry tasks. For this purpose, terminals may be placed directly in patient examination rooms allowing key data to be entered contemporaneously by the physician away from the physician's office. In addition, techniques such as dictation can be used to simplify the entry by a physician of observation notes into computer-readable text suitable for electronic record systems.
[0004] Dictation may not be practical in many situations, for example, in the presence of the patient where it would be distracting or confusing. Although most computers have some sound processing capability, dictation on a standard computer is often cumbersome and less than satisfactory, requiring special-purpose sound capture hardware, headsets or desktop microphones that are difficult to use and which clutter a workspace.
[0005] One method of simplifying data entry is by the use of “templates” that provide a framework for a patient note with “fill-in blanks”, for example, provided by menu lists that may be selected among by a physician. These templates can be “smart”, that is, informed by underlying information from electronic medical system database, so that the template is pre-populated with elements from the patient's record once the patient identification is entered. One limitation with templates is that they can be inflexible and poorly adapted recording unique observations related to a particular patient.
[0006] The mobile nature of a physician's practice in which the physician moves between patient examination rooms or makes rounds at a hospital, has led to increased interest in transferring the data entry process from a desktop environment to portable devices such as tablet computers. Current portable devices present a trade-off between portability and ease of data entry. For example, current touchscreen keyboards are a less efficient alternative than a standard keyboard and mouse combination for common text data entry, a problem exacerbated by the frequent lack of a stabilizing surface for the portable device that would permit easy two-handed typing. The size and clarity of the display for a portable device, in a range of different environments, is normally less than can be provided on a desktop machine in a fixed location and orientation. While the technology exists to increase the capabilities of portable devices, these modifications will still confront the inevitable tradeoff between portability and capability, with additional features likely to decrease portability both in terms of size (possibly eliminating the ability to place the device in a coat pocket or the like) and power usage (increases affecting the ability to operate the device over the entire workday on reasonably sized batteries).
SUMMARY OF THE INVENTION
[0007] The present inventors have recognized that improved medical data entry workflow can be obtained by observing the comparative advantages of different data entry devices by permitting seamless transition between these devices during data entry. This seamless workflow between devices is made possible by a workflow queue which both identifies pending workflow and provides content descriptors and workflow state information allowing integration of data collected on two devices. The invention specifically may exploit the comparative advantages of sophisticated desktop workstations and highly portable devices such as smart phones. The former provides for greater processing power display and superior text entry and network communication, while the latter provides superior portability and audio processing. By recognizing the complementary strengths of each device, total workflow can be improved.
[0008] Specifically, the invention provides a multi-device workflow system for medical data entry using a first and second data entry device each having at least one data entry interface permitting a user to enter medical data, a communication channel interface permitting communication between the first and second data entry device; and a processor for executing application programs. At least one application program on the first data entry device executes to: (i) receive medical data entry from the user in a medical file; (ii) designate, in a workflow queue, additional medical data for the medical file for input on the second data entry device, the workflow queue further storing content descriptor for the additional medical data indicating at least one of a patient being a subject of the additional medical data and the medical file; and (iii) transmit the workflow queue to the second data entry device. At least one application program on the second data entry device executes to: (i) receive the workflow queue from the first data entry device;, (ii) display the content descriptor to the user for additional medical data entry; (iii) receive the additional medical data entry from the user linked to the content descriptor; and (iv) transmit the additional medical data as linked to the content descriptor to the first data entry device.
[0009] It is thus a feature of at least one embodiment of the invention to permit a single data entry task to be simply divided over multiple devices and times.
[0010] The application on the first data entry device may automatically open the medical file for acceptance of the additional medical data therein.
[0011] It is thus a feature of at least one embodiment of the invention to minimize the additional steps necessary when multiple devices are employed while preserving flexibility to provide data entry tasks for a variety of files.
[0012] The content descriptor may include at least one insertion point in the medical file for the additional medical data and the application on the first data entry device upon review of the additional medical data by the user, automatically inserts the additional medical data at the insertion point.
[0013] It is thus a feature of at least one embodiment of the invention to permit fine-grained division of data entry tasks even within a single medical file.
[0014] The data entry interface of the second device may be a microphone and the additional medical data may be dictation.
[0015] It is thus a feature of at least one embodiment of the invention to permit seamless intermixing of text entry on one device with dictation on a second device.
[0016] The second application program may transmit the additional medical data to the first data entry device via a transcriber.
[0017] It is thus a feature of at least one embodiment of the invention to employ the intercommunication between devices to provide intervening services such as transcription
[0018] The medical file may be a patient note describing a patient office visit.
[0019] It is thus a feature of at least one embodiment of the invention to improve common but critical patient note generation.
[0020] The first application program may receive medical data entry from the user in a medical file via a template having menu choices for adding data to the medical file and permitting free text entry for adding data to the medical file.
[0021] It is thus a feature of at least one embodiment of the invention to permit integration of a template system and dictation performed at different times.
[0022] The data entry interface of the second device may be a camera and the additional medical data is at least one digital photograph.
[0023] It is thus a feature of at least one embodiment of the invention to leverage the native ability of cameras with digital transmission capabilities to add images efficiently into medical records.
[0024] The second device may be a cellular phone.
[0025] It is thus a feature of at least one embodiment of the invention to incorporate medical data entry capabilities into a multipurpose device that may be normally carried by a physician.
[0026] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a simplified block diagram of the principal components of an electronic medical record system communicating with a variety of different data entry terminal types such as may be used with the present invention;
[0028] FIG. 2 is a block diagram of two data entry devices linked by a workflow queue of the present invention;
[0029] FIG. 3 is a data flow diagram showing generation of the workflow queue upon initiation of data entry at a first data entry device;
[0030] FIG. 4 is a screen display of the workflow queue of FIG. 3 at a second data entry device receiving the workflow queue;
[0031] FIG. 5 is a figure similar to that of FIG. 3 showing initiation of a data entry task on a remote portable device and in particular the acquisition of photographs; and
[0032] FIG. 6 is a representation of two screen displays used to promote an understanding of the secure treatment of medical records entered through a remote device such as a cell phone.
[0033] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] Referring now to FIG. 1 , an electronic medical record system 10 may provide for a clinical database 12 providing a data storage system 14 holding a clinical record database 16 that may be served by an electronic medical record server 18 to a network 20 . The electronic medical record server, for example, may be the EpicCare EMR manufactured by Epic Systems Corporation of Verona, Wis. As will be understood to those of ordinary skill in the art, a clinical record database 16 is one prepared under the supervision of healthcare professionals and having limited access per HIPAA requirements to provide a record keeping system on which health care decisions may be founded.
[0035] The network 20 may attach to various workstations 22 a - 22 c providing secured access to the clinical record database 16 and containing stored application programs working in conjunction with the server 18 to permit reading and writing of the clinical record database 16 in a healthcare setting.
[0036] The workstations 22 are typically, but not necessarily, desktop or laptop computers or the like having a large area display screen 30 (for example a 15 inch diagonal or larger), a mechanical keyboard 32 , and a mouse 34 or the like communicating with a processor/memory system 36 . Workstation 22 a, for example, may be used by a transcriptionist while workstations 22 b and 22 c may be in physician offices or the like.
[0037] The network 20 may also communicate with one or more access points 38 , for example, providing a local area wireless network or a cellular telephone network, to provide for connection of wireless portable devices 40 , for example tablet computers or cellular phones and in particular so called “smart” phones, permitting the installation of third-party applications.
[0038] Referring now to FIG. 2 , a typical workstation 22 c may provide for a processor 42 connected via an internal bus 44 with a memory 46 including, for example, volatile random access memory 48 and nonvolatile mass storage memory 50 such as flash memory or a hard disk drive. The bus 44 may also communicate with one or more interfaces 52 a - 52 c communicating respectively with a network media 54 , for example an Ethernet cable, the keyboard 32 , mouse 34 , and the screen 30 .
[0039] The mobile device 40 may include a microcontroller 56 communicating with a display 58 , for example a touchscreen display also permitting the entry of data, a microphone 60 , a camera 62 , a speaker 64 , a radio transceiver 66 , and a memory 67 . The mobile device 40 may also include a battery system 68 providing power to the previously mentioned elements. Currently, suitable portable devices 40 may include the iPhone manufactured by Apple Computer or a similar cell phone running the Android operating system manufactured by Google.
[0040] The workstation 22 c or mobile device 40 are provided by way of example to illustrate devices with contrasting capabilities such as currently exist in the medical environment. The mechanical keyboard 32 , mouse 34 , and large-screen 30 of the workstation 22 c simplify and speed accurate data entry as well as the review of multiple sources of data. The greater power of the processor of the workstation 22 c permits improved multitasking between different data accessing applications that may be held in the memory 46 and the network media 54 provides faster network data access. Generally, such workstations 22 c are not well adapted for sound processing (either playing sound or recording sound) both as a result of technical limitations and also as a result of limitations imposed by the environment (e.g. desk space for microphones, difficulty in limiting the transmission of sound from speakers, lack of privacy, and lack of remote access). Workstations 22 may further be operatively precluded from effective sound processing when they are accessed remotely via systems such as Citrix which are designed to pass keystroke and video data to a remote terminal but cannot transmit or are less effective at transmitting audio data. In contrast, the mobile device 40 , particularly in the case when the mobile device 40 is a cell phone, may have sophisticated sound handling components including microphone 60 and speaker 64 readily integrated into a housing which may be held near the user's mouth and ear or which may receive an earphone/microphone combination. In addition, portable devices 40 have high accessibility because they are portable and may be carried with the physician. Generally, however, data entry in the form of text is cumbersome on such portable devices 40 .
[0041] It is contemplated that each workstation 22 will execute a program providing an authentication procedure to ensure only proper individuals can enter data into the clinical record database 16 . It will be understood that similar authentication can be used on the mobile device 40 ; however, because the data from the mobile device 40 , per the present invention, will be reviewed by a physician or other healthcare professional at a workstation 22 , a high degree of authentication may not be required.
[0042] The present invention synergistically combines these data entry devices to provide a more versatile yet seamless data entry experience for the physician. The invention employs a workflow queue 70 that may be transferred between workstation 22 c and mobile device 40 to permit data entry tasks to flexibly span these two devices and different times. Generally, the workflow queue 70 may be created on either workstation 22 c or mobile device 40 when a data entry task is begun and then transferred to the other workstation 22 c or mobile device 40 for completion of that data-entry task.
[0043] Referring now to FIG. 3 , data entry on the workstation 22 c may, for example, provide for a data entry program 72 executing on the workstation 22 c for the creation of a medical document, in this case a patient note 74 being a prose description of the patient visit. The patient note 74 may be prepared by the physician, for example, using a template which provides a skeletal text framework having blanks that may be filled in manually or through the assistance of pulldown menus providing different choices for the blanks. The entries in some of the blanks may be used to automatically populate other blanks making use of linkages between data found in the clinical record database 16 as may be read by the data entry program 72 . For example, entry of a patient identifying information may automatically populate entries related to the patient age, gender, etc taken from the clinical record database 16 .
[0044] The result of selections in data entry by the physician is a medical file having lines of text 76 . At various points within the text 76 , the physician may opt to dictate text entries not well accommodated by the template structure. These points may be marked with flags 78 which, for example, may be indicated graphically by a character embedded in the text 76 visible to the physician on the screen 30 . Upon the entry of a flag 78 , a menu 80 may be provided with choices 82 denoting generally the content description of the text, for example, “additional patient history”. The content description will provide a reminder to the physician at the time of later data entry what additional data needs to be collected.
[0045] At the time of the opening of the data entry program 72 and the selection of a choice 82 , a workflow queue 70 may be created that will be populated with a pointer 86 to each flag 78 linked to a content descriptor 88 identifying the needed additional data. For example, the content descriptor 88 may be the choice 82 taken from the menu 80 and describing the dictation that needs to be added at these points.
[0046] The queue entry 84 will also receive task information 90 indicating the data entry program 72 for which this data is required. This task information 90 may be derived from the data entry program 72 itself and program state information 73 . The task information 90 , for example, may include the name of the data entry program 72 (for example, represented by a path and executable file name) necessary to invoke the data entry program 72 and may include state data necessary to initialize the data entry program 72 to the point of data entry, as well as identify the document path for the patient note 74 to be generated. The queue entry 84 may also include command line information or context information 92 generally indicating the patient record 94 in the clinical record database 16 for which the data entry program 72 has been invoked providing, for example, patient ID information and information with respect to the field to which the patient note 74 belongs as one record field. In FIG. 3 , the database records are indicated by rows and fields by columns according to conventional abstraction. Together, the pointer 86 , the task information 90 and the context information 92 provide state information about the state of the data entry program 72 necessary to permit insertion of additional data at the flags 78 .
[0047] It will be understood that some of this data may be derived from other of the data through, for example, reference to the clinical record database 16 . The queue entry 84 , therefore, need not physically hold this data directly provided the necessary data can be derived from information of the queue entry 84 .
[0048] The workflow queue 70 may have multiple queue entries 84 related to different patients and different data entry programs 72 as may be generated by the physician over a period of time. Different workflow queues 70 may be provided for different physicians.
[0049] Referring again to FIGS. 1 and 2 , the workflow queue 70 may be maintained on the workstation 22 c and transferred from the workstation 22 c to the network 20 as indicated by arrow 96 or be maintained on the server 18 and transferred from server 18 to the network 20 as indicated by arrow 98 , and ultimately to the mobile device 40 per arrow 100 . This transfer may be invoked by the mobile device 40 by the physician at a later time.
[0050] Referring to FIG. 4 , an application program executed on the mobile device 40 may then provide for a graphic representation 102 on display 58 representing each queue entry 84 . The graphic representation 102 may provide a human readable representation of the task information 90 and the context information 92 for each queue entry 84 . In this case, that representation includes a patient name, date, and time suitable to identify the patient associated with the patient note 74 . The data entry program 72 (that of creating a patient note) is implicit in this example. The graphic representation 102 may also include a text representation of the content descriptor 88 identifying the additional information required. In this case, the need for dictation may be inferred from the task information 90 or explicitly denoted by the content descriptor 88 , causing the application program to provide dictation control buttons 104 or to call an appropriate dictation application program. In this example, the dictation control buttons 104 provide for a start (and stop), a review, and a send function which operate together to allow dictation to be recorded, played back for review. Other function buttons such as those that allow editing or trimming of the dictation can also be provided.
[0051] In one embodiment, pressing the send button may forward the dictation to workstation 22 a for transcription and from there, ultimately, to workstation 22 c. This may be accomplished within the confines of the electronic record system 10 by storing the audio data as a file on the centralized server 18 or another similar server. From there, a transcriptionist may link to the file from their workstation 22 a and transcribe and enter the text into the clinical record database 16 . Alternatively, the recording may be sent to a third party transcription service via a secure internet connection or the like. The third party transcriptionist or text to speech conversion program may then send the transcribed text back to the clinical record database automatically, or optionally via an operator at a terminal 22 who may enter it into the clinical record database 16 .
[0052] The dictated additional data is inserted into the queue entry 84 associated with pointer 86 (or otherwise linked to this data) so that upon completion it may automatically be re-inserted into the partially completed data entry of the patient note 74 using the application identified by the queue entry 84 and the pointer 86 for placement of the transcribed text into the patient note 74 . In this way, the physician may use the superior sound recording qualities of the mobile device 40 as well as its ability to be used in a private location to complete sensitive or detailed dictation.
[0053] Referring now to FIG. 5 , an equally valuable allocation of data entry tasks can occur driven by data first collected at the mobile device 40 , for example, from the physician making rounds at a hospital and collecting information that may be incorporated into the medical record or patient note yet to be generated. In a data entry program 72 the physician, for example, may use dictation as described before or text entry or the superior capabilities of the mobile device 40 for photography, the latter to take one or more photographs 106 of the patient. The photographs 106 , for example, may generate a queue entry 84 providing a picture identifier 87 to the particular photograph linked to photograph content descriptor 88 . The photograph content descriptor 88 may be a text label provided by the physician or, at a minimum, the time and date of the photograph. The queue entry 84 is tagged with the task information 90 and context information 92 , as before. In this case, the context information may be obtained from a locally held round list 108 listing patients to be visited by the physician. It is contemplated that individual patients on the round list 108 may be automatically selected, for example, through use of proximity signals in the particular patient room, for example, from an RFID tag bar code or local transmission as the physician visits those patients. Alternatively, the round list 108 may be downloaded from the electronic medical record system and a patient manually selected by the physician.
[0054] In this case, the task information 90 may identify the photography application used to create the photographs 106 but alternatively, or in addition, may identify a companion task of data entry at the workstation 22 c that would receive such information and that may be implicit in the photography application. In this way, when the workflow queue 70 is transferred back to the workstation 22 c, when the queue entry 84 is invoked on the graphic representation 102 , it may open in the desired data entry application for receiving the photographs with command line arguments bringing up the desired patient records from the context information 92 . Photographs acquired remotely can be readily integrated into the patient record by the physician. The companion task may be inferred from the data collected and the task information 90 . Alternatively, the companion task may be expressly selected from a menu or the like (not shown).
[0055] The present invention also contemplates that a given queue entry 84 may automatically spawn additional queue entries 84 according to a set of rules or tasks automatically invoked by the selection of a first companion task. For example, a physician may begin a patient note in a hospital room invoking a first queue entry 84 for later completion of the patient note 74 at the physician's full workstation 22 c. This queue entry 84 may invoke a second queue entry 84 linked to a different companion task of entering a charge for the patient visit in a billing program also at the physicians workstation 22 c. This second queue entry 84 may identify a billing program in the task information 90 but may otherwise use identical or similar data for the context information 92 . The content descriptor 88 may be automatically generated from the context or from the menu used to identify the first companion task.
[0056] When the physician returns to his or her workstation 22 c, a graphic representation 102 of queue entries will show representations of two queue entry 84 : one for completion of the patient note 74 in the data entry program 72 , and the second for completion of the billing information in a billing program, for example, by entering billing codes or the like. Selection of the representation of the second queue entry 84 will open a billing entry for the particular patient possibly partially populated with the content descriptor 88 . Alternatively, this billing task completion may be forwarded to another workstation 22 a for completion by a nonphysician specialist.
[0057] Referring to FIG. 6 , the present inventors recognize that the benefits of using a common cell phone for medical data entry carries with it a risk of patient concern about confidentiality. Such concerns are allayed first by providing secure communication between the mobile device 40 and the network 20 , by proper authentication of the user by the application on the mobile device 40 assuring access only by appropriate healthcare professionals, and second by providing visual confirmation to the patient with respect to proper treatment of the acquired information. Accordingly, the present invention may provide a first display screen 110 visible on the mobile device 40 prior to data acquisition, for example, that may be shown to the patient to indicate the running of a secure medical data acquisition program. This display screen may, for example, show the logo of the healthcare institution and clearly indicate that the mobile device 40 is being used as a secure medical record entry device. In the case of photographs, upon sending of the photographs, a display 112 depicting destruction of the photograph may be used to provide visual confirmation to the physician and patient of the full erasure of the data from the mobile device 40 . The application may provide for a limited duration of storage to ensure data is not retained on the portable device beyond a predetermined period in the event that the mobile device 40 is lost and improperly read. This confirmation may be accompanied by or supplanted by an audible tone or spoken message.
[0058] It will be appreciated that the mobile device 40 may be used not simply for photographs or dictation but may also be used for the entry of quantitative information that may be obtained during rounds by the physician, this information to be imported into the patient record or patient notes at a later time. Such information can include vital readings such as blood pressure and temperature, observed information, results of lab tests transferred manually, and the like. The photographs or other information may be attached to the generated queue entry 84 or sent separately and linked to the queue entry 84 .
[0059] In one embodiment, the originally opened template may automatically generate additional medical data collection tasks for the mobile device 40 so that the collection data may precede actual generation of the patient note by a physician. In this case, the photographs may be cued by an automatically generated queue.
[0060] Generally, the term “queue” should not be considered to require any particular data structure but only data that provides for the functionality described above. When the terms “physician” or “doctor” are used herein, they should be considered to include healthcare professionals generally, including nurses and physician assistants.
[0061] Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.
[0062] When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
[0063] References to “a server” and “a processor” can be understood to include one or more controllers or processors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network. It should be understood that a computer program may embrace constituent programs and that multiple programs may be implemented as a single or multiple programs.
[0064] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications are hereby incorporated herein by reference in their entireties.
[0065] Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.
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A system for facilitating patient data entry for mobile physicians provides for a task queue allowing partial data entry on different devices during the day according to the comparative advantage of the device. Thus, for example, a patient note may be prepared at an office terminal and some transcription added at a later time as dictated into a cell phone or the like. The queue structure provides informational cues to the physician to remind him or her of later data entry tasks and permits seamless integration of fragmented data entry into a common record.
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TECHNICAL FIELD
[0001] The present invention relates to a liquid crystal display and a method for displaying images.
BACKGROUND OF THE INVENTION
[0002] LCD (Liquid Crystal Display) panels suffer from motion blur due to their sample-and-hold nature, i.e. the LC (Liquid Crystal) remains in the same state after addressing during a whole frame. When displayed objects move, as is the case in e.g. TV images, this causes a blurred image of the objects on the retina of a viewer. Flashing the backlight solves the sample-and-hold effect because a light pulse exposures the display panel for a short time every frame. By segmentation of the backlight and by linking the timing of the flash of each segment to the sequential addressing scheme of the display panel, a light pulse scans the picture. This is normally called scrolling or scanning backlight.
[0003] In US 2002/0067332 A1, it is disclosed a liquid crystal display device having a backlight arrangement comprising six light sources each arranged to backlight a part of the display. A problem is pointed out that if lighting and extinguishing is performed equally for all light sources, a profile of an image displayed at upper and lower side portions appear in duplicate.
[0004] This is solved, according to US 2002/0067332 A1, either by always having the uppermost and lowermost light sources lit, or by shifting the phase for lighting and extinguishing the uppermost and lowermost light sources, or increasing the frequency for lighting and extinguishing the uppermost and lowermost light sources, or decreasing the supply current for the uppermost and lowermost light sources, or spacing the uppermost and lowermost light sources apart from neighboring light sources, or applying a different duty cycle for lighting and extinguishing the uppermost and lowermost light sources compared to other light sources of the backlighting arrangement.
[0005] However, the effectiveness of these measure appears to be limited in practice, and therefore there is a need for an improved backlight control to avoid a blurred image.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the present invention to provide an improved display, and improved method for displaying images on a display.
[0007] The present invention is based on the understanding that effective illumination of a display deviates from backlight timing according to a given backlight input signal due to the backlight optics cross talk of light between the segments in combination with a LC-transmission effect.
[0008] The above object is achieved according to a first aspect of the present invention by a liquid crystal display according to the independent Claim 1 . Further advantageous embodiments are defined in the dependent Claims. An advantage of this liquid crystal display is improved image quality, especially far from the center of the display, due to improved timing between backlighting of a section of the display panel and refresh of corresponding pixels within that section. These functions do not have to be linear or symmetrical.
[0009] A controller is provided for controlling a timing between backlighting and pixel refresh, in dependence of a location of a section within the display panel.
[0010] This controller is preferably arranged for providing an advance in timing of backlighting for sections at a first end of the display panel, with respect to refreshing of pixel in these sections, and for providing a delay in timing of backlighting for sections at a second end of the display panel opposite to the first end, with respect to the refreshing of pixels in these sections.
[0011] The advance for each section at said first end may be an increasing function of a distance of said each section from a center of the display, and the delay for each section at said other end may be an increasing function of a distance of said each section from the center of the display.
[0012] An advantage of these ways to control backlight timing where effective backlight timing is considered is accurate backlighting in relation to refresh of corresponding pixels to reduce risk for pre-ghost and post-ghost images.
[0013] The controller may comprise a refresh timing controller arranged to control timing of said refresh of picture elements in relation to said backlighting depending on a location of a picture element to be refreshed within the display panel.
[0014] The control of said refresh timing may comprise a delay, related to a backlighting timing of corresponding picture elements, of refresh timing at a position at a first end of said display panel, and an advance, related to a backlighting timing of corresponding picture elements, of refresh timing at a position at a second end opposite to said first end of said display panel.
[0015] The advance of refresh timing at said first end may be an increasing function of a distance of corresponding picture element from a center of the display, and the delay of refresh timing at said other end may be an increasing function of a distance of corresponding picture element from the center of the display.
[0016] An advantage of these ways to control refresh timing in relation to effective backlight timing is reduced risk for pre-ghost and post-ghost images.
[0017] Distribution of lighting devices and size of each of said sections associated with any of said lighting devices may depend on said position of said each section.
[0018] An advantage of this is an optimized design of the backlighting unit to reduce risk for pre-ghost and post-ghost images.
[0019] The above object is achieved according to a second aspect of the present invention by a method for displaying images on a display comprising a display panel and a backlight unit, wherein the backlight unit comprises a plurality of lighting devices each associated with a section of the display panel to provide a backlighting to the corresponding section of the display panel, comprising the steps of refreshing picture elements of the display panel repeatedly; backlighting each of the sections of the display panel corresponding to the refresh of the picture elements; and controlling timing between the refreshing and the backlighting depending on a corresponding position on the display.
[0020] The controlling of timing may comprise the step of controlling backlighting timing for each section.
[0021] The step of controlling backlighting timing may comprise the steps of
[0022] advancing, related to a refresh timing of corresponding picture elements, backlighting timing for sections at a first end of said display panel; and
[0023] delaying, related to a refresh timing of corresponding picture elements, backlighting timing for sections at a second end opposite to said first end of said display panel.
[0024] The advance for each section at said first end may be an increasing function of a distance of said each section from a center of the display, and the delay for each section at said other end may be an increasing function of a distance of said each section from the center of the display.
[0025] The controlling of timing may comprise the step of controlling refresh timing.
[0026] The step of controlling refresh timing may comprise the steps of: delaying refresh timing for picture elements at a first end of said display panel; and advancing refresh timing for picture elements at a second end opposite to said first end of said display panel.
[0027] The delay of refresh timing for picture elements at said first end may be an increasing function of a distance of picture elements from a center of the display, and the advance of refresh timing for picture elements at said other end may be an increasing function of a distance of picture elements from the center of the display.
[0028] Advantages of the second aspect of the present invention are similar to those of the first aspect of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, wherein:
[0030] FIG. 1 is a time versus light signal diagram for an exemplary backlight pulse of a single lamp or segment without the influence of neighboring lamps;
[0031] FIG. 2 is a diagram illustrating an LC-transmission curve;
[0032] FIG. 3 is a time versus light signal diagram for an exemplary effective backlight pulse;
[0033] FIG. 4 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to prior art;
[0034] FIG. 5 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention;
[0035] FIG. 6 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention;
[0036] FIG. 7 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention;
[0037] FIG. 8 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention;
[0038] FIG. 9 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention;
[0039] FIG. 10 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention;
[0040] FIG. 11 illustrates a display according to an embodiment of the present invention;
[0041] FIG. 12 is a block diagram schematically illustrating a backlight controller according to an embodiment of the present invention;
[0042] FIG. 13 is a block diagram schematically illustrating a backlight controller according to an embodiment of the present invention; and
[0043] FIG. 14 illustrates the influence of cross talk between segments.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0044] FIG. 1 is a time versus light signal diagram for an exemplary backlight pulse. In this case the backlight pulse is symmetric, but any pulse shape is possible, e.g. an asymmetrical pulse. However, the effect, described below, that an effective backlight pulse will have another shape than the intended backlight pulse, still applies. Current backlight designs have no perfect segmentation. Due to cross talk of light pulses of neighboring segments, the scan pulse is the summation of several light pulses from close-by lamps. As a result, the shape and phase of the scan pulse is screen position dependent, as illustrated in FIG. 14 . As is pointed out in FIG. 14 , the scanning light pulse is the summation 1401 - 1407 of the effect 1408 - 1414 of all lamps. This is vertical position dependent, i.e. dependent on the actual segment. The consequence of the poor segmentation is an asymmetrical scanning pulse at the top and bottom of the screen. Hence “the center of gravity” of the light pulse shifts in time and is no longer in phase with the addressing scheme of the panel, i.e. the refresh of pixels. In practice the shape of the light pulse is even more complicated due to non-gaussian light distribution and turn on and off behavior of the lamps. The duty cycle has a big influence on the shape of the light pulse as well but not or hardly on the curve of the effective sampling moment. As a result of the light pulse shift the amplitude of the ghost images will change over the vertical position of the screen. Therefore, for the top segments, the effective sampling moment is delayed 1415 due to poor segmentation, and the effective sampling moment is earlier for bottom segments, i.e. less delay 1416 .
[0045] FIG. 2 is a diagram illustrating an LC-transmission curve, which the observed light pulse is affected by. Therefore, an effective panel illumination output, as depicted by FIG. 3 , will have a reformed shape, in this example the symmetrical backlight pulse of FIG. 1 has become an asymmetrical effective panel illumination output as depicted in FIG. 3 .
[0046] FIG. 4 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to prior art. The repeated pixel refresh timing for each position at each time form lines 400 , 402 , 404 in the diagram. A backlight unit comprises a plurality of lighting devices, each associated with a section of the display, i.e. associated with a range of positions, where the activation of the lighting devices are depicted by blocks 406 . The activation signal for each lighting device is depicted as a block, where the duration of the activation signal is the prolongation in time direction of the block, and the positions covered by the lighting device is the extension in position direction of the block. In practice there is overlap in vertical direction of the blocks due to poor segmentation. Preferably, the backlight of the display is scanned to, with a time offset, synchronized with the refresh of pixels. The time offset should be such that there is as much time as possible from the previous refresh until lighting the backlight to avoid post-ghost images due to the slow settlement of the liquid crystal, and a proper time distance between the extinguishing of the backlight before next refresh to avoid pre-ghost images. However, due to cross talk of segments in the backlight, the effective backlighting is, as depicted by the dotted line 408 . As can be seen from the diagram of FIG. 4 , the effective backlighting timing 408 does not coincide with a constant offset to the next refresh 402 . This is problem due to the LC-transmission curve described in FIG. 2 . An approximation of the timing has to be done at the design, e.g. where a proper offset is achieved for positions in the middle of the display, and a tangible deviation from the proper offset is present at the end positions on the display. In the present example, there is a risk for pre-ghost images at a first end, e.g. the top of the display when scanned from top to bottom, while there is a risk for post-ghost images at the other end of the display. The present invention, as discussed in connection with FIGS. 5 , 6 , and 7 , present embodiments for providing a proper offset between the effective backlighting timing and the refresh timing for the entire display. Especially in combination with over-drive to suppress post-ghosts a constant offset is required.
[0047] FIG. 5 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention. The repeated pixel refresh timing for each position at each time form lines 500 , 502 , 504 in the diagram. A backlight unit comprises a plurality of lighting devices, each associated with a section of the display, i.e. associated with a range of positions, where the activation of the lighting devices are depicted by blocks 506 . The activation signal for each lighting device is depicted as a block, where the duration of the activation signal is the prolongation in time direction of the block, and the positions covered by the lighting device is the extension in position direction of the block. Preferably, the backlight of the display is scanned to, with a time offset, coincide with the refresh of pixels. However, in this embodiment, the timing of the backlighting is adapted to comprise a lag at positions at a first end of the display and to comprise a lead at positions at the other end. Due to the crosstalk, as described in connection with FIG. 14 , the effective backlighting timing now form a linear timing characteristic, as depicted by the dotted line 508 .
[0048] As can be seen from the diagram of FIG. 5 , the effective backlighting timing 508 coincides with a constant offset to the next refresh 502 . Thus, the risk for ghost images is reduced. If overdrive is not implemented it is best not to optimize for a constant offset but for the smallest local offset without pre-ghosts. Hence, the top segments can be delayed less, or not at all, because at the top the lamp can not introduce a pre-ghost due to light cross talk to a segment above it.
[0049] FIG. 6 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention. A backlight unit comprises a plurality of lighting devices, each associated with a section of the display, i.e. associated with a range of positions, where the activation of the lighting devices are depicted by blocks 606 . The activation signal for each lighting device is depicted as a block, where the duration of the activation signal is the prolongation in time direction of the block, and the positions covered by the lighting device is the extension in position direction of the block. Preferably, the backlight of the display is scanned to, with a time offset, coincide with refresh of pixels. However, in this embodiment, the timing of the refresh of pixels is adapted to comprise a lead at positions at a first end of the display and to comprise a lag at positions at the other end. Therefore, the repeated pixel refresh timing for each position at each time form curved lines 600 , 602 , 604 in the diagram. As can be seen from the diagram of FIG. 6 , the effective backlighting timing 608 coincides with a constant offset to the refresh 602 , since the curved timing characteristics form a similar curvature. Thus, the risk for ghost images is reduced.
[0050] FIG. 7 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention. The repeated pixel refresh timing for each position at each time form lines 700 , 702 , 704 in the diagram. A backlight unit comprises a plurality of lighting devices, each associated with a section of the display, i.e. associated with a range of positions, where the activation of the lighting devices are depicted by blocks 706 . The activation signal for each lighting device is depicted as a block, where the duration of the activation signal is the prolongation in time direction of the block, and the positions covered by the lighting device is the extension in position direction of the block. Preferably, the backlight of the display is scanned to, with a time offset, coincide with the refresh of pixels. However, in this embodiment, the sizes of the lighting devices and the corresponding sections are adapted to comprise medium sizes at positions at a first end of the display, small sizes at positions in the middle, and larger sizes at positions at the other end. Due to the crosstalk, as described in connection with FIG. 14 , the effective backlighting timing now form a linear timing characteristic, as depicted by the dotted line 708 . As can be seen from the diagram of FIG. 7 , the effective backlighting timing 708 coincides with a constant offset to the refresh 702 . In case the smaller segments in the center of the backlight are implemented by placing more, e.g. identical, lamps closer together, the local light output will increase. Hence the duty cycle of the lamps should be reduced, e.g. proportional to the locale lamp distance. Shorter duty cycles and smaller segments will both shorten the effective scan pulse, hence a sharper moving picture will be experienced in the center of the screen.
[0051] The principles depicted in the embodiments depicted in FIGS. 5 , 6 , and 7 can be applied in any combination to form suitable refresh timing characteristics and backlighting characteristics, and thereby achieve a proper offset between effective backlighting timing and pixel refresh timing.
[0052] FIG. 8 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention. To provide a simple implementation, reduced scan speed 800 of the backlight is provided together with a pre-delay 802 at a first end of the display. Thus, the risk of pre-ghost images is reduced at the first end of the display, and the risk of post-ghost images is reduced at the other end.
[0053] FIG. 9 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention. To provide a simple implementation, reduced scan speed 900 of the backlight is provided together with a pre-delay 902 at a first end of the display. Further, the first and last lighting devices are provided with an extra time shift to further reduce the risk of pre-ghost images at the first end of the display, and the risk of post-ghost images at the other end. Therefore, a first lighting block 904 is advanced in time with a time advance 906 , and a last lighting block 908 is delayed with a delay 910 .
[0054] FIG. 10 is a diagram showing refresh timing of pixels and backlight scanning illustrated by position on the screen versus time according to an embodiment of the present invention. To provide a simple implementation, reduced scan speed 1000 , 1002 of the backlight is provided in two steps together with pre-delay 1004 , 1006 . Thus, the risk of pre-ghost images is reduced at the first end of the display, and the risk of post-ghost images is reduced at the other end, while a proper timing is achieved at positions in the middle of the display.
[0055] FIG. 11 illustrates a display 1100 comprising a display panel 1102 . The display panel 1102 , which can be a LCD (Liquid Crystal Display) panel, is provided with a plurality of lighting devices 1105 . Each of the lighting devices 1105 can for example comprise one or more lighting sources, such as light emitting diodes (LEDs) or gas discharge lamps. The backlight is flashed by scanning lighting devices 1105 . Thus, an LC cell is illuminated only for a certain fraction of the frame time. A backlight controller 1104 , which is connected to the lighting devices 1105 of the panel 1102 , controls backlight flashing. To avoid ghost images, the backlight controller 1104 provides backlight control signals which are dependent on the position of an associated part of the panel 1102 . Therefore, the backlight controller is connected to a display controller 1106 , which in turn receives image data from an image data source 1108 . It should be noted that this description is for illustrative purpose, and both the backlight controller 1104 and the display controller 1106 can be a common video controller, or divided between two or more units, which provide the same function as the backlight and display controllers 1104 , 1106 . The data source 1108 can be a TV decoder, a DVD player, a computer, or any other means providing images to be viewed on the display 1100 .
[0056] FIG. 12 is a block diagram schematically illustrating a backlight controller 1200 according to an embodiment of the present invention. The backlight controller 1200 comprises a mode variables input 1202 , a backlight parameter input 1204 , and a synchronization input 1206 . The inputs 1202 , 1204 , 1206 receive information from a video controller. The mode variables input 1202 receives information on number of lines, blanking, and/or front porch. The backlight parameter input 1204 receives information on lamp distance, scan speed, pre-delay, and/or light distribution curve. The synchronization input receives information on horizontal synchronization, vertical synchronization, and/or data enable.
[0057] The backlight controller 1200 further comprises a calculator 1208 and a counter 1210 . The mode variables input 1202 and the backlight parameter input 1204 is connected to the calculator 1208 for providing information, such that the calculator can calculate lamp turn-off data 1212 . The Synchronization input is connected to the counter 1210 to enable the counter to provide row number 1214 and pixel number 1216 .
[0058] The backlight controller further comprises a sequencer 1218 and a lamp I/O 1220 . The lamp turn-off data 1212 , the row number 1214 , and the pixel number 1216 is provided to the sequencer 1218 . The sequencer 1218 calculates the turn-on data offset and provides control information 1222 to the lamp I/O 1220 according to any of the principles described in connection with FIGS. 5-10 , or any combination of those principles, to provide improved backlighting for reduced ghost images. The lamp I/O controls the flashing of the lighting devices 1105 in FIG. 11 according to the control information 1222 .
[0059] FIG. 13 is a block diagram schematically illustrating a backlight controller 1300 according to an embodiment of the present invention. The backlight controller 1300 comprises a backlight level input 1301 , a mode variables input 1302 , a backlight parameter input 1304 , and a synchronization input 1306 . The inputs 1301 , 1302 , 1304 , 1306 receive information from a video controller. The backlight level input 1301 receives information on dynamic light output. The mode variables input 1302 receives information on number of lines, blanking, and/or front porch. The backlight parameter input 1304 receives information on lamp distance, scan speed, pre-delay, and/or light distribution curve. The synchronization input receives information on horizontal synchronization, vertical synchronization, and/or data enable.
[0060] The backlight controller 1300 further comprises a look-up table (LUT) 1307 , a calculator 1308 and a counter 1310 . The backlight level input 1301 is connected to the LUT 1307 for providing information on dynamic backlighting, such as reduced lamp duty cycle, which can be symmetric or asymmetric to provide a dynamic backlighting signal 1311 . The mode variables input 1302 and the backlight parameter input 1304 is connected to the calculator 1308 for providing information, such that the calculator can calculate lamp turn-off data 1312 . The Synchronization input is connected to the counter 1310 to enable the counter to provide row number 1314 and pixel number 1316 .
[0061] The backlight controller further comprises a sequencer 1318 and a lamp I/O 1320 . The dynamic backlight signal 1311 , the lamp turn-off data 1313 , the row number 1314 , and the pixel number 1316 is provided to the sequencer 1318 . The sequencer 1318 provides control information 1322 to the lamp I/O 1320 according to any of the principles described in connection with FIGS. 5-10 , or any combination of those principles, to provide improved backlighting for reduced ghost images. The lamp I/O controls the flashing of the lighting devices 1105 in FIG. 11 according to the control information 1322 .
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A liquid crystal display ( 1100 ) is disclosed, comprising a liquid crystal display panel ( 1102 ), a backlight unit, and a controller ( 1104, 1200, 1300 ). The liquid crystal display panel ( 1102 ) comprises a plurality of picture elements, wherein said picture elements are refreshed repeatedly, said backlight unit comprises a plurality of lighting devices ( 1105 ) each associated with a section of the display panel ( 1102 ) and arranged to provide backlighting to said section of the display panel ( 1102 ), and said controller ( 1104, 1200, 1300 ) is arranged to control timing, between refresh of picture elements and said backlighting by the lighting device corresponding to the section of the picture elements to be refreshed, in dependence on a position of the section associated with said corresponding lighting device. The controller comprises a backlighting controller for each of said sections, which backlighting controller is arranged to control backlighting timing depending on said position of said each section, wherein said control of backlighting timing comprises an advance, related to a refresh timing of corresponding picture elements, of backlighting timing for sections at a first end of said display panel, and a delay, related to a refresh timing of corresponding picture elements, of backlighting timing at a section at a second end opposite to said first end of said display panel ( 1102 ). Further, a method for displaying images on such a display is disclosed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national phase under the provisions of 35 U.S.C. §371 of International Patent Application No. PCT/US13/21200 filed Jan. 11, 2013, which in turn claims priority of U.S. Provisional Patent Application No. 61/585,778 filed Jan. 12, 2012. The disclosures of such international patent application and U.S. priority provisional patent application are hereby incorporated herein by reference in their respective entireties, for all purposes.
FIELD OF THE INVENTION
The present invention is directed to compounds methods and compositions that are useful as inhibitors of the hepatitis C virus (HCV) NS3 protease, the synthesis of such compounds, and the use of such compounds for treating HCV infection and or reducing the likelihood or severity of symptoms of HCV infection.
BACKGROUND OF THE INVENTION
Hepatitis C virus (HCV) has infected more than 180 million people worldwide. It is estimated that three to four million persons are newly infected each year, 70% of whom will develop chronic hepatitis. HCV is responsible for 50-76% of all liver cancer cases, and two thirds of all liver transplants in the developed world. Standard therapy (pegylated interferon alpha plus ribavirin) is only effective in 50-60% of patients; however, its effectiveness is not well understood and it is associated with significant side-effects. Therefore, there is an urgent need for new drugs to treat and/or cure HCV (1: Chen K X, Njoroge F G. A review of HCV protease inhibitors. Curr Opin Investig Drugs. 2009 8, 821-37; 2: Garg G, Kar P. Management of HCV infection: current issues and future options. Trop Gastroenterol. 2009 30, 11-8; 3: Pereira A A, Jacobson I M. New and experimental therapies for HCV. Nat Rev Gastroenterol Hepatol. 2009 7, 403-11).
The HCV genome comprises a positive-strand RNA enclosed in a nucleocapsid and lipid envelope and consists of 9.6 kb ribonucleotides, which encodes a large polypeptide of about 3000 amino acids (Dymock et al. Antiviral Chemistry & Chemotherapy 2000, 11, 79). Following maturation, this polypeptide is cut into at least 10 proteins. The NS3 serine protease, located in the N-terminal domain of the NS3 protein, mediates all of the subsequent cleavage events downstream in the polyprotein. Because of its role, the NS3 serine protease is an ideal drug target and previous research has shown hexapeptides as well as tripeptides show varying degrees of inhibition, as discussed in U.S. patent applications US2005/0020503, US2004/0229818, and US2004/00229776. Macrocyclic compounds that exhibit anti-HCV activity have also been disclosed in International patent applications nos. WO20061119061, WO2007/015855 and WO2007/016441 (all Merck & Co., Inc.).
The discovery of novel antiviral strategies to selectively inhibit HCV replication has long been hindered by the lack of convenient cell culture models for the propagation of HCV. This hurdle has been overcome first with the establishment of the HCV replicon system in 1999 (Bartenschlager, R., Nat. Rev. Drug Discov. 2002, 1, 911-916 and Bartenschlager, R., J. Hepatol. 2005, 43, 210-216) and, in 2005, with the development of robust HCV cell culture models (Wakita, T., et al., Nat. Med. 2005, 11, 791-6; Zhong, J., et al., Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 9294-9; Lindenbach, B. D., et al., Science 2005, 309, 623-6).
It would be advantageous to provide new antiviral or chemotherapy agents, compositions including these agents, and methods of treatment using these agents, particularly to treat drug resistant or mutant viruses. The present invention provides such agents, compositions and methods.
SUMMARY OF THE INVENTION
The present invention provides compounds, methods and compositions for treating or preventing HCV infection in a host. The compounds have the following general formula:
where R, J, and J 1 are as defined hereinbelow.
The methods involve administering a therapeutically or prophylactically-effective amount of at least one compound as described herein to treat or prevent an infection by, or an amount sufficient to reduce the biological activity of HCV infection. The pharmaceutical compositions include one or more of the compounds described herein, in combination with a pharmaceutically acceptable carrier or excipient, for treating a host with HCV. The formulations can further include at least one further therapeutic agent. In addition, the present invention includes processes for preparing such compounds.
Hepatitis C replicons require viral helicase, protease, and polymerase to be functional in order for replication of the replicon to occur. The replicons can be used in high throughput assays, which evaluate whether a compound to be screened for activity inhibits the ability of HCV helicase, protease, and/or polymerase to function, as evidenced by an inhibition of replication of the replicon.
DETAILED DESCRIPTION
The compounds described herein show inhibitory activity against HCV. Therefore, the compounds can be used to treat or prevent a viral infection in a host, or reduce the biological activity of the virus. The host can be a mammal, and in particular, a human, infected with HCV. The methods involve administering an effective amount of one or more of the compounds described herein.
Pharmaceutical formulations including one or more compounds described herein, in combination with a pharmaceutically acceptable carrier or excipient, are also disclosed. In one embodiment, the formulations include at least one compound described herein and at least one further therapeutic agent.
The present invention will be better understood with reference to the following definitions:
I. Definitions
The terms “independently” is used herein to indicate that the variable, which is independently applied, varies independently from application to application. Thus, in a compound such as R″XYR″, wherein R″ is “independently carbon or nitrogen,” both R″ can be carbon, both R″ can be nitrogen, or one R″ can be carbon and the other R″ nitrogen.
As used herein, the term “enantiomerically pure” refers to a compound composition that comprises at least approximately 95%, and, preferably, approximately 97%, 98%, 99% or 100% of a single enantiomer of that compound.
As used herein, the term “substantially free of” or “substantially in the absence of” refers to a compound composition that includes at least 85 to 90% by weight, preferably 95% to 98% by weight, and, even more preferably, 99% to 100% by weight, of the designated enantiomer of that compound. In a preferred embodiment, the compounds described herein are substantially free of enantiomers.
Similarly, the term “isolated” refers to a compound composition that includes at least 85 to 90% by weight, preferably 95% to 98% by weight, and, even more preferably, 99% to 100% by weight, of the compound, the remainder comprising other chemical species or enantiomers.
The term “alkyl,” as used herein, unless otherwise specified, refers to a saturated straight, branched, or cyclic, primary, secondary, or tertiary hydrocarbons, including both substituted and unsubstituted alkyl groups. The alkyl group can be optionally substituted with any moiety that does not otherwise interfere with the reaction or that provides an improvement in the process, including but not limited to but limited to halo, haloalkyl, hydroxyl, carboxyl, acyl, aryl, acyloxy, amino, amido, carboxyl derivatives, alkylamino, dialkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, thiol, imine, sulfonyl, sulfanyl, sulfinyl, sulfamonyl, ester, carboxylic acid, amide, phosphonyl, phosphinyl, phosphoryl, phosphine, thioester, thioether, acid halide, anhydride, oxime, hydrazine, carbamate, phosphonic acid, phosphonate, either unprotected, or protected as necessary, as known to those skilled in the art, for example, as taught in Greene, et al., Protective Groups in Organic Synthesis , John Wiley and Sons, Second Edition, 1991, hereby incorporated by reference. Specifically included are CF 3 and CH 2 CF 3
In the text, whenever the term C(alkyl range) is used, the term independently includes each member of that class as if specifically and separately set out. The term “alkyl” includes C 1-22 alkyl moieties, and the term “lower alkyl” includes C 1-6 alkyl moieties. It is understood to those of ordinary skill in the art that the relevant alkyl radical is named by replacing the suffix “-ane” with the suffix “-yl”.
The term “alkenyl” refers to an unsaturated, hydrocarbon radical, linear or branched, in so much as it contains one or more double bonds. The alkenyl group disclosed herein can be optionally substituted with any moiety that does not adversely affect the reaction process, including but not limited to but not limited to those described for substituents on alkyl moieties. Non-limiting examples of alkenyl groups include ethylene, methylethylene, isopropylidene, 1,2-ethane-diyl, 1,1-ethane-diyl, 1,3-propane-diyl, 1,2-propane-diyl, 1,3-butane-diyl, and 1,4-butane-diyl.
The term “alkynyl” refers to an unsaturated, acyclic hydrocarbon radical, linear or branched, in so much as it contains one or more triple bonds. The alkynyl group can be optionally substituted with any moiety that does not adversely affect the reaction process, including but not limited to those described above for alkyl moeities. Non-limiting examples of suitable alkynyl groups include ethynyl, propynyl, hydroxypropynyl, butyn-1-yl, butyn-2-yl, pentyn-1-yl, pentyn-2-yl, 4-methoxypentyn-2-yl, 3-methylbutyn-1-yl, hexyn-1-yl, hexyn-2-yl, and hexyn-3-yl, 3,3-dimethylbutyn-1-yl radicals.
The term “alkylamino” or “arylamino” refers to an amino group that has one or two alkyl or aryl substituents, respectively.
The term “protected” as used herein and unless otherwise defined refers to a group that is added to an oxygen, sulfur, nitrogen, or phosphorus atom to prevent its further reaction or for other purposes. A wide variety of oxygen and nitrogen protecting groups are known to those skilled in the art of organic synthesis, and are described, for example, in Greene et al., Protective Groups in Organic Synthesis, supra.
The term “aryl”, alone or in combination, means a carbocyclic aromatic system containing one, two or three rings wherein such rings can be attached together in a pendent manner or can be fused. Non-limiting examples of aryl include phenyl, biphenyl, or naphthyl, or other aromatic groups that remain after the removal of a hydrogen from an aromatic ring. The term aryl includes both substituted and unsubstituted moieties. The aryl group can be optionally substituted with any moiety that does not adversely affect the process described herein for preparing the compounds, including but not limited to but not limited to those described above for alkyl moieties. Non-limiting examples of substituted aryl include heteroarylamino, N-aryl-N-alkylamino, N-heteroarylamino-N-alkylamino, heteroaralkoxy, arylamino, aralkylamino, arylthio, mono aryl amidosulfonyl, arylsulfonamido, diarylamidosulfonyl, monoaryl amidosulfonyl, arylsulfinyl, arylsulfonyl, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, aroyl, heteroaroyl, aralkanoyl, heteroaralkanoyl, hydroxyaralkyl, hydoxyheteroaralkyl, haloalkoxyalkyl, aryl, aralkyl, aryloxy, aralkoxy, aryloxyalkyl, saturated heterocyclyl, partially saturated heterocyclyl, heteroaryl, heteroaryloxy, heteroaryloxyalkyl, arylalkyl, heteroarylalkyl, arylalkenyl, and heteroarylalkenyl, carboaralkoxy.
The terms “alkaryl” or “alkylaryl” refer to an alkyl group with an aryl substituent. The terms “aralkyl” or “arylalkyl” refer to an aryl group with an alkyl substituent.
The term “halo,” as used herein, includes chloro, bromo, iodo and fluoro.
The term “acyl” refers to a carboxylic acid ester in which the non-carbonyl moiety of the ester group is selected from straight, branched, or cyclic alkyl or lower alkyl, alkoxyalkyl including but not limited to methoxymethyl, aralkyl including but not limited to benzyl, aryloxyalkyl such as phenoxymethyl, aryl including but not limited to phenyl optionally substituted with halogen (F, Cl, Br, I), alkyl (including but not limited to C 1 , C 2 , C 3 , and C 4 ) or alkoxy (including but not limited to C 1 , C 2 , C 3 , and C 4 ), sulfonate esters such as alkyl or aralkyl sulphonyl including but not limited to methanesulfonyl, the mono, di or triphosphate ester, trityl or monomethoxytrityl, substituted benzyl, trialkylsilyl (e.g., dimethyl-t-butylsilyl) or diphenylmethylsilyl. Aryl groups in the esters optimally comprise a phenyl group. The term “lower acyl” refers to an acyl group in which the non-carbonyl moiety is lower alkyl.
The terms “alkoxy” and “alkoxyalkyl” embrace linear or branched oxy-containing radicals having alkyl moieties, such as methoxy radical. The term “alkoxyalkyl” also embraces alkyl radicals having one or more alkoxy radicals attached to the alkyl radical, that is, to form monoalkoxyalkyl and dialkoxyalkyl radicals. The “alkoxy” radicals can be further substituted with one or more halo atoms, such as fluoro, chloro or bromo, to provide “haloalkoxy” radicals. Examples of such radicals include fluoromethoxy, chloromethoxy, trifluoromethoxy, difluoromethoxy, trifluoroethoxy, fluoroethoxy, tetrafluoroethoxy, pentafluoroethoxy, and fluoropropoxy.
The term “alkylamino” denotes “monoalkylamino” and “dialkylamino” containing one or two alkyl radicals, respectively, attached to an amino radical. The terms arylamino denotes “monoarylamino” and “diarylamino” containing one or two aryl radicals, respectively, attached to an amino radical. The term “aralkylamino”, embraces aralkyl radicals attached to an amino radical. The term aralkylamino denotes “monoaralkylamino” and “diaralkylamino” containing one or two aralkyl radicals, respectively, attached to an amino radical. The term aralkylamino further denotes “monoaralkyl monoalkylamino” containing one aralkyl radical and one alkyl radical attached to an amino radical.
The term “heteroatom,” as used herein, refers to oxygen, sulfur, nitrogen and phosphorus.
The terms “heteroaryl” or “heteroaromatic,” as used herein, refer to an aromatic that includes at least one sulfur, oxygen, nitrogen or phosphorus in the aromatic ring or a combination of two or more heteroatoms (O, S, N, P) in an aromatic system. Both five membered and six membered ring heteroaryls are contemplated herein, as are five and six membered ring heteroaryls linked to a benzene ring, such as benzofuran, benzthiophene, benzopyrrole, and the like.
The term “heterocyclic,” “heterocyclyl,” and cycloheteroalkyl refer to a nonaromatic cyclic group wherein there is at least one heteroatom, such as oxygen, sulfur, nitrogen, or phosphorus in the ring.
Nonlimiting examples of heteroaryl and heterocyclic groups include furyl, furanyl, pyridyl, pyrimidyl, thienyl, isothiazolyl, imidazolyl, tetrazolyl, pyrazinyl, benzofuranyl, benzothiophenyl, quinolyl, isoquinolyl, benzothienyl, isobenzofuryl, pyrazolyl, indolyl, isoindolyl, benzimidazolyl, purinyl, carbazolyl, oxazolyl, thiazolyl, isothiazolyl, 1,2,4-thiadiazolyl, isooxazolyl, pyrrolyl, quinazolinyl, cinnolinyl, phthalazinyl, xanthinyl, hypoxanthinyl, thiophene, furan, pyrrole, isopyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, oxazole, isoxazole, thiazole, isothiazole, pyrimidine or pyridazine, and pteridinyl, aziridines, thiazole, isothiazole, 1,2,3-oxadiazole, thiazine, pyridine, pyrazine, piperazine, pyrrolidine, oxaziranes, phenazine, phenothiazine, morpholinyl, pyrazolyl, pyridazinyl, pyrazinyl, quinoxalinyl, xanthinyl, hypoxanthinyl, pteridinyl, 5-azacytidinyl, 5-azauracilyl, triazolopyridinyl, imidazolopyridinyl, pyrrolopyrimidinyl, pyrazolopyrimidinyl, adenine, N 6 -alkylpurines, N 6 -benzylpurine, N 6 -halopurine, N 6 -vinypurine, N 6 -acetylenic purine, N 6 -acyl purine, N 6 -hydroxyalkyl purine, N 6 -thioalkyl purine, thymine, cytosine, 6-azapyrimidine, 2-mercaptopyrmidine, uracil, N 5 -alkylpyrimidines, N 5 -benzylpyrimidines, N 5 -halopyrimidines, N 5 -vinylpyrimidine, N 5 -acetylenic pyrimidine, N 5 -acyl pyrimidine, N 5 -hydroxyalkyl purine, and N 6 -thioalkyl purine, and isoxazolyl. The heteroaromatic group can be optionally substituted as described above for aryl. The heterocyclic or heteroaromatic group can be optionally substituted with one or more substituent selected from halogen, haloalkyl, alkyl, alkoxy, hydroxy, carboxyl derivatives, amido, amino, alkylamino, dialkylamino. The heteroaromatic can be partially or totally hydrogenated as desired. As a nonlimiting example, dihydropyridine can be used in place of pyridine. Functional oxygen and nitrogen groups on the heterocyclic or heteroaryl group can be protected as necessary or desired. Suitable protecting groups are well known to those skilled in the art, and include trimethylsilyl, dimethylhexylsilyl, t-butyldimethylsilyl, and t-butyldiphenylsilyl, trityl or substituted trityl, alkyl groups, acyl groups such as acetyl and propionyl, methanesulfonyl, and p-toluenelsulfonyl. The heterocyclic or heteroaromatic group can be substituted with any moiety that does not adversely affect the reaction, including but not limited to but not limited to those described above for aryl.
The term “host,” as used herein, refers to a unicellular or multicellular organism in which the virus can replicate, including but not limited to cell lines and animals, and, preferably, humans. Alternatively, the host can be carrying a part of the viral genome, whose replication or function can be altered by the compounds of the present invention. The term host specifically refers to infected cells, cells transfected with all or part of the viral genome and animals, in particular, primates (including but not limited to chimpanzees) and humans. In most animal applications of the present invention, the host is a human patient. Veterinary applications, in certain indications, however, are clearly contemplated by the present invention (such as for use in treating chimpanzees).
The term “peptide” refers to a various natural or synthetic compound containing two to one hundred amino acids linked by the carboxyl group of one amino acid to the amino group of another.
The term “pharmaceutically acceptable salt or prodrug” is used throughout the specification to describe any pharmaceutically acceptable form of a compound that upon administration to a patient, provides the parent compound. Pharmaceutically acceptable salts include those derived from pharmaceutically acceptable inorganic or organic bases and acids. Suitable salts include those derived from alkali metals such as potassium and sodium, alkaline earth metals such as calcium and magnesium, among numerous other acids well known in the pharmaceutical art. Pharmaceutically acceptable prodrugs refer to a compound that is metabolized, for example hydrolyzed or oxidized, in the host to form the compound of the present invention. Typical examples of prodrugs include compounds that have biologically labile protecting groups on functional moieties of the active compound. Prodrugs include compounds that can be oxidized, reduced, aminated, deaminated, hydroxylated, dehydroxylated, hydrolyzed, dehydrolyzed, alkylated, dealkylated, acylated, deacylated, phosphorylated, or dephosphorylated to produce the active compound. The prodrug forms of the compounds of this invention can possess antiviral activity, can be metabolized to form a compound that exhibits such activity, or both.
II. Active Compound
The compounds described herein have the following general formula:
or a pharmaceutically acceptable salt or prodrug thereof, wherein
J and J 1 can be present or absent when present are independently selected from lower alkyl (C 1 -C 6 ), aryl, arylalkyl, alkoxy, aryloxy, heterocyclyl, heterocyclyloxy, keto, hydroxy, amino, arylamino, carboxyalkyl, carboxamidoalkyl, halo, cyano, formyl, sulfonyl, or sulfonamido; and
R is (C 1 -C 10 ) alkyl, C 3-8 cycloalkyl, alkenyl (C 2 -C 10 ), alkynyl (C 2 -C 10 ), aryl, heteroaryl, or heterocyclyl each containing 1 to 9 fluorine atoms and/or 1 to 3 silicon atoms.
III. Stereoisomerism and Polymorphism
The compounds described herein may have asymmetric centers and occur as racemates, racemic mixtures, individual diastereomers or enantiomers, with all isomeric forms being included in the present invention. Compounds of the present invention having a chiral center can exist in and be isolated in optically active and racemic forms. Some compounds can exhibit polymorphism. The present invention encompasses racemic, optically active, polymorphic, or stereoisomeric forms, or mixtures thereof, of a compound of the invention, which possess the useful properties described herein. The optically active forms can be prepared by, for example, resolution of the racemic form by recrystallization techniques, by synthesis from optically active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase or by enzymatic resolution.
Optically active forms of the compounds can be prepared using any method known in the art, including but not limited to by resolution of the racemic form by recrystallization techniques, by synthesis from optically-active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase.
Examples of methods to obtain optically active materials include at least the following.
i) physical separation of crystals: a technique whereby macroscopic crystals of the individual enantiomers are manually separated. This technique can be used if crystals of the separate enantiomers exist, i.e., the material is a conglomerate, and the crystals are visually distinct; ii) simultaneous crystallization: a technique whereby the individual enantiomers are separately crystallized from a solution of the racemate, possible only if the latter is a conglomerate in the solid state; iii) enzymatic resolutions: a technique whereby partial or complete separation of a racemate by virtue of differing rates of reaction for the enantiomers with an enzyme; iv) enzymatic asymmetric synthesis: a synthetic technique whereby at least one step of the synthesis uses an enzymatic reaction to obtain an enantiomerically pure or enriched synthetic precursor of the desired enantiomer; v) chemical asymmetric synthesis: a synthetic technique whereby the desired enantiomer is synthesized from an achiral precursor under conditions that produce asymmetry (i.e., chirality) in the product, which can be achieved using chiral catalysts or chiral auxiliaries; vi) diastereomer separations: a technique whereby a racemic compound is reacted with an enantiomerically pure reagent (the chiral auxiliary) that converts the individual enantiomers to diastereomers. The resulting diastereomers are then separated by chromatography or crystallization by virtue of their now more distinct structural differences and the chiral auxiliary later removed to obtain the desired enantiomer; vii) first- and second-order asymmetric transformations: a technique whereby diastereomers from the racemate equilibrate to yield a preponderance in solution of the diastereomer from the desired enantiomer or where preferential crystallization of the diastereomer from the desired enantiomer perturbs the equilibrium such that eventually in principle all the material is converted to the crystalline diastereomer from the desired enantiomer. The desired enantiomer is then released from the diastereomer; viii) kinetic resolutions: this technique refers to the achievement of partial or complete resolution of a racemate (or of a further resolution of a partially resolved compound) by virtue of unequal reaction rates of the enantiomers with a chiral, non-racemic reagent or catalyst under kinetic conditions; ix) enantiospecific synthesis from non-racemic precursors: a synthetic technique whereby the desired enantiomer is obtained from non-chiral starting materials and where the stereochemical integrity is not or is only minimally compromised over the course of the synthesis; x) chiral liquid chromatography: a technique whereby the enantiomers of a racemate are separated in a liquid mobile phase by virtue of their differing interactions with a stationary phase (including but not limited to via chiral HPLC). The stationary phase can be made of chiral material or the mobile phase can contain an additional chiral material to provoke the differing interactions; xi) chiral gas chromatography: a technique whereby the racemate is volatilized and enantiomers are separated by virtue of their differing interactions in the gaseous mobile phase with a column containing a fixed non-racemic chiral adsorbent phase; xii) extraction with chiral solvents: a technique whereby the enantiomers are separated by virtue of preferential dissolution of one enantiomer into a particular chiral solvent; xiii) transport across chiral membranes: a technique whereby a racemate is placed in contact with a thin membrane barrier. The barrier typically separates two miscible fluids, one containing the racemate, and a driving force such as concentration or pressure differential causes preferential transport across the membrane barrier. Separation occurs as a result of the non-racemic chiral nature of the membrane that allows only one enantiomer of the racemate to pass through.
Chiral chromatography, including but not limited to simulated moving bed chromatography, is used in one embodiment. A wide variety of chiral stationary phases are commercially available.
IV. Compound Salt or Prodrug Formulations
In cases where compounds are sufficiently basic or acidic to form stable nontoxic acid or base salts, administration of the compound as a pharmaceutically acceptable salt may be appropriate. Examples of pharmaceutically acceptable salts are organic acid addition salts formed with acids, which form a physiological acceptable anion, for example, tosylate, methanesulfonate, acetate, citrate, malonate, tartarate, succinate, benzoate, ascorbate, α-ketoglutarate and α-glycerophosphate. Suitable inorganic salts can also be formed, including but not limited to, sulfate, nitrate, bicarbonate and carbonate salts.
Pharmaceutically acceptable salts can be obtained using standard procedures well known in the art, for example by reacting a sufficiently basic compound such as an amine with a suitable acid, affording a physiologically acceptable anion. Alkali metal (e.g., sodium, potassium or lithium) or alkaline earth metal (e.g., calcium, magnesium) salts of carboxylic acids can also be made.
V. Methods of Treatment
Hosts, including but not limited to humans, infected with HCV or a gene fragment thereof, can be treated by administering to the patient an effective amount of the active compound or a pharmaceutically acceptable prodrug or salt thereof in the presence of a pharmaceutically acceptable carrier or diluent. The active materials can be administered by any appropriate route, for example, orally, parenterally, intravenously, intradermally, subcutaneously, or topically, in liquid or solid form.
VI. Combination or Alternation Therapy
In one embodiment, the compounds of the invention can be employed together with at least one other antiviral agent.
Table of anti-HCV Compounds Approved or in Preclinical and Clinical Development Pharmaceutical Drug Name Drug Category Company PEGASYS Long acting interferon Roche pegylated interferon alfa-2a INFERGEN Interferon, Long acting interferon InterMune interferon alfacon-1 OMNIFERON Interferon, Long acting interferon Viragen natural interferon ALBUFERON Longer acting interferon Human Genome Sciences REBIF Interferon Ares-Serono interferon beta-1a Omega Interferon Interferon BioMedicine Oral Interferon alpha Oral Interferon Amarillo Biosciences Interferon gamma- Anti-fibrotic InterMune 1b IP-501 Anti-fibrotic Interneuron Merimebodib VX-497 IMPDH inhibitor (inosine Vertex monophosphate dehydrogenase) AMANTADINE Broad Antiviral Agent Endo Labs (Symmetrel) Solvay IDN-6556 Apotosis regulation Idun Pharma. XTL-002 Monclonal Antibody XTL HCV/MF59 Vaccine Chiron CIVACIR Polyclonal Antibody NABI Therapeutic vaccine Innogenetics VIRAMIDINE Nucleoside Analogue ICN ZADAXIN (thymosin Immunomodulator Sci Clone alfa-1) CEPLENE Immunomodulator Maxim histamine dihydrochloride VX 950/ Protease Inhibitor Vertex/Eli Lilly LY 570310 ISIS 14803 Antisense Isis Pharmaceutical/ Elan IDN-6556 Caspase inhibitor Idun Pharmaceuticals, Inc. http://www.idun.com JTK 003 Polymerase Inhibitor AKROS Pharma Tarvacin Anti-Phospholipid Therapy Peregrine HCV-796 Polymerase Inhibitor ViroPharma/ Wye CH-6 Serine Protease Schering ANA971 Isatoribine ANADYS ANA245 Isatoribine ANADYS CPG 10101 (Actilon) Immunomodulator Coley Rituximab (Rituxam) Anti-CD20 Monoclonal Antibody Genetech/IDEC NM283 Polymerase Inhibitor Idenix Pharmaceuticals (Valopicitabine) HepX ™-C Monclonal Antibody XTL IC41 Therapeutic Vaccine Intercell Medusa Interferon Longer acting interferon Flamel Technologies E-1 Therapeutic Vaccine Innogenetics Multiferon Long Acting Interferon Viragen BILN 2061 Serine Protease Boehringer-Ingelheim Interferon beta-1a Interferon Ares-Serono (REBIF)
VII. Pharmaceutical Compositions
Hosts, including but not limited to humans, infected with hepatitis C virus (“HCV”), or a gene fragment thereof, can be treated by administering to the patient an effective amount of the active compound or a pharmaceutically acceptable prodrug or salt thereof in the presence of a pharmaceutically acceptable carrier or diluent. The active materials can be administered by any appropriate route, for example, orally, parenterally, intravenously, intradermally, subcutaneously, or topically, in liquid or solid form.
A preferred dose of the compound will be in the range of between about 0.1 and about 100 mg/kg, more generally, between about 1 and 50 mg/kg, and, preferably, between about 1 and about 20 mg/kg, of body weight of the recipient per day. The effective dosage range of the pharmaceutically acceptable salts and prodrugs can be calculated based on the weight of the parent compound to be delivered. If the salt or prodrug exhibits activity in itself, the effective dosage can be estimated as above using the weight of the salt or prodrug, or by other means known to those skilled in the art.
The compound is conveniently administered in unit any suitable dosage form, including but not limited to one containing 7 to 3,000 mg, preferably 70 to 1,400 mg of active ingredient per unit dosage form. An oral dosage of 50-1,000 mg is usually convenient.
Ideally the active ingredient should be administered to achieve peak plasma concentrations of the active compound from about 0.2 to 70 μM, preferably about 1.0 to 15 μM. This can be achieved, for example, by the intravenous injection of a 0.1 to 5% solution of the active ingredient, optionally in saline, or administered as a bolus of the active ingredient.
The concentration of active compound in the drug composition will depend on absorption, inactivation and excretion rates of the drug as well as other factors known to those of skill in the art. It is to be noted that dosage values will also vary with the severity of the condition to be alleviated. It is to be further understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that the concentration ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed composition. The active ingredient can be administered at once, or can be divided into a number of smaller doses to be administered at varying intervals of time.
A preferred mode of administration of the active compound is oral. Oral compositions will generally include an inert diluent or an edible carrier. They can be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches or capsules. Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition.
The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel or corn starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring. When the dosage unit form is a capsule, it can contain, in addition to material of the above type, a liquid carrier such as a fatty oil. In addition, unit dosage forms can contain various other materials that modify the physical form of the dosage unit, for example, coatings of sugar, shellac, or other enteric agents.
The compound can be administered as a component of an elixir, suspension, syrup, wafer, chewing gum or the like. A syrup can contain, in addition to the active compound(s), sucrose or sweetener as a sweetening agent and certain preservatives, dyes and colorings and flavors.
The compound or a pharmaceutically acceptable prodrug or salts thereof can also be mixed with other active materials that do not impair the desired action, or with materials that supplement the desired action, such as antibiotics, antifungals, anti-inflammatories or other antivirals, including but not limited to nucleoside compounds. Solutions or suspensions used for parenteral, intradermal, subcutaneous, or topical application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents, such as ethylenediaminetetraacetic acid; buffers, such as acetates, citrates or phosphates, and agents for the adjustment of tonicity, such as sodium chloride or dextrose. The parental preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.
If administered intravenously, preferred carriers are physiological saline or phosphate buffered saline (PBS).
In a preferred embodiment, the active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including but not limited to implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters and polylactic acid. For example, enterically coated compounds can be used to protect cleavage by stomach acid. Methods for preparation of such formulations will be apparent to those skilled in the art. Suitable materials can also be obtained commercially.
Liposomal suspensions (including but not limited to liposomes targeted to infected cells with monoclonal antibodies to viral antigens) are also preferred as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art, for example, as described in U.S. Pat. No. 4,522,811 (incorporated by reference). For example, liposome formulations can be prepared by dissolving appropriate lipid(s) (such as stearoyl phosphatidyl ethanolamine, stearoyl phosphatidyl choline, arachadoyl phosphatidyl choline, and cholesterol) in an inorganic solvent that is then evaporated, leaving behind a thin film of dried lipid on the surface of the container. An aqueous solution of the active compound is then introduced into the container. The container is then swirled by hand to free lipid material from the sides of the container and to disperse lipid aggregates, thereby forming the liposomal suspension.
The terms used in describing the invention are commonly used and known to those skilled in the art. As used herein, the following abbreviations have the indicated meanings:
aq aqueous CDI carbonyldiimidazole DCM dichloromethane DIPEA N,N-diisopropylethylamine DMSO dimethylsulfoxide EDCI 1-ethyl-3-(3-dimethyllaminopropyl)carbodiimide hydrochloride EtOAc ethyl acetate h hour/hours M molar min minute NMP N-methylpyrrolidone OXYMA ethyl 2-cyano-2-(hydroxyimino)acetate rt or RT room temperature THF tetrahydrofuran
IX. General Procedures for Preparing Active Compounds
Methods for the preparation of the compounds of this invention can be prepared as described in detail below in the “Specific Example” section, or by other methods known to those skilled in the art. It will be understood by one of ordinary skill in the art that these schemes are in no way limiting and that variations of detail can be made without departing from the spirit and scope of the present invention.
Analogs of the general formula, in which J and J 1 are present, can be prepared, for example, by using a substituted form of the starting material:
where J and J 1 are
as defined herein, or, where these moieties would interfere with the coupling chemistry described in Scheme I, are protected groups that can be converted to the desired J and J 1 moieties after the coupling chemistry is completed, or at a later step in the overall synthesis.
Compounds of this formula are known, and can be prepared using no more than routine experimentation. Those skilled in the art will readily understand that incorporation of substituents onto the aryl ring can be readily realized, either before the core structures are prepared, or afterward (i.e., the substituents can be present during key coupling steps, or can be added after the unsubstituted compound (i.e., without the J and/or J 1 moieties) has been prepared. Such substituents can provide useful properties in and of themselves, or serve as a handle for further synthetic elaboration. One proviso is that such substitution should either survive the synthesis conditions, or should be added after the synthesis is otherwise complete.
For example, the aryl ring can be halogenated using various known procedures, which vary depending on the particular halogen. Examples of suitable reagents include bromine/water in concentrated HBr, thionyl chloride, pyr-IC1, fluorine and Amberlyst-A. A number of other analogs, bearing substituents in a diazotized position of an aryl ring, can be synthesized from the corresponding aniline compounds, via the diazonium salt intermediate. The diazonium salt intermediates can be prepared using known chemistry, for example, treatment of aromatic amines such as aniline with sodium nitrite in the presence of a mineral acid.
Diazonium salts can be formed from anilines, which in turn can be prepared from nitrobenzenes (and analogous amine-substituted heteroaryl rings can be prepared from nitro-substituted heteroaryl rings). The nitro derivatives can be reduced to the amine compound by reaction with a nitrite salt, typically in the presence of an acid. Other substituted analogs can be produced from diazonium salt intermediates, including, but are not limited to, hydroxy, alkoxy, fluoro, chloro, iodo, cyano, and mercapto, using general techniques known to those of skill in the art. Likewise, alkoxy analogues can be made by reacting the diazonium salt with alcohols. The diazonium salt can also be used to synthesize cyano or halo compounds, as will be known to those skilled in the art. Mercapto substitutions can be obtained using techniques described in Hoffman et al., J. Med. Chem. 36: 953 (1993). The mercaptan so generated can, in turn, be converted to an alkylthio substitutent by reaction with sodium hydride and an appropriate alkyl bromide. Subsequent oxidation would then provide a sulfone. Acylamido analogs of the aforementioned compounds can be prepared by reacting the corresponding amino compounds with an appropriate acid anhydride or acid chloride using techniques known to those skilled in the art of organic synthesis.
Hydroxy-substituted analogs can be used to prepare corresponding alkanoyloxy-substituted compounds by reaction with the appropriate acid, acid chloride, or acid anhydride. Likewise, the hydroxy compounds are precursors of both the aryloxy and heteroaryloxy via nucleophilic aromatic substitution at electron deficient aromatic rings. Such chemistry is well known to those skilled in the art of organic synthesis. Ether derivatives can also be prepared from the hydroxy compounds by alkylation with alkyl halides and a suitable base or via Mitsunobu chemistry, in which a trialkyl- or triarylphosphine and diethyl azodicarboxylate are typically used. See Hughes, Org. React . ( N.Y .) 42: 335 (1992) and Hughes, Org. Prep. Proced. Int. 28: 127 (1996) for typical Mitsunobu conditions.
Cyano-substituted analogs can be hydrolyzed to afford the corresponding carboxamido-substituted compounds. Further hydrolysis results in formation of the corresponding carboxylic acid-substituted analogs. Reduction of the cyano-substituted analogs with lithium aluminum hydride yields the corresponding aminomethyl analogs. Acyl-substituted analogs can be prepared from corresponding carboxylic acid-substituted analogs by reaction with an appropriate alkyllithium using techniques known to those skilled in the art of organic synthesis.
Carboxylic acid-substituted analogs can be converted to the corresponding esters by reaction with an appropriate alcohol and acid catalyst. Compounds with an ester group can be reduced with sodium borohydride or lithium aluminum hydride to produce the corresponding hydroxymethyl-substituted analogs. These analogs in turn can be converted to compounds bearing an ether moiety by reaction with sodium hydride and an appropriate alkyl halide, using conventional techniques. Alternatively, the hydroxymethyl-substituted analogs can be reacted with tosyl chloride to provide the corresponding tosyloxymethyl analogs, which can be converted to the corresponding alkylaminoacyl analogs by sequential treatment with thionyl chloride and an appropriate alkylamine. Certain of these amides are known to readily undergo nucleophilic acyl substitution to produce ketones.
Hydroxy-substituted analogs can be used to prepare N-alkyl- or N-arylcarbamoyloxy-substituted compounds by reaction with N-alkyl- or N-arylisocyanates. Amino-substituted analogs can be used to prepare alkoxycarboxamido-substituted compounds and urea derivatives by reaction with alkyl chloroformate esters and N-alkyl- or N-arylisocyanates, respectively, using techniques known to those skilled in the art of organic synthesis.
Similarly, benzene rings can be substituted using known chemistry, including the reactions discussed above. For example, the nitro group on nitrobenzene can be reacted with sodium nitrite to form the diazonium salt, and the diazonium salt manipulated as discussed above to form the various substituents on a benzene ring.
The substituents described above can therefore be added to the starting benzene ring, and incorporated into the final compounds described herein.
Introduction of the R substituent of the general formula can be carried out as described below. Starting from compound I (synthesis of I detailed in U.S. Provisional Patent Application No. 61/408,989 filed on Nov. 1, 2010, and outlined in Schemes 1 and 2 above), removal of the tert-butoxycarbonyl group with conditions such as acid (including TFA or HCl) allows for introduction of an activated carbonyl species, such as acyl imidazole, that can subsequently be reacted with a suitable nucleophile containing one or more silicon atoms as defined above. In the example below trimethylsilyl ethanol, II is used as the silicon-containing nucleophile to produce III.
Additional silicon containing alcohols are listed below and in no way is this list intended to limit the selection of possible silicon containing compounds, III or the synthetic route used for their synthesis.
The synthesis of fluorine containing R groups of the general structure can be preformed as outlined below. Again starting from I as described above, the amino group can be exposed, then acylated, for example, with a fluorine-substituted formate derivative, such as IV, to provide fluorine derivative V. Compound IV (Bioorganic & Medicinal Chemistry 19 (2011) 1580-1593) can be prepared from an appropriate fluorine-containing alcohol, carbonyl diimidazole and methyl iodide.
Additional fluorine containing alcohols are listed below and in no way is this list intended to limit the selection of possible fluorine containing compounds, V or the synthetic route used for their synthesis.
SPECIFIC EXAMPLES
Specific compounds which are representative of this invention were prepared as per the following examples; the examples and the diagrams are offered by way of illustration, to aid in the understanding of the invention and should not be construed to limit in any way the invention set forth in the claims which follow thereafter. One skilled in the art would know how to increase such yields through routine variations in reaction times, temperatures, solvents and/or reagents.
Example 1
Mitochondrial Toxicity Assays in HepG2 Cells:
i) Effect of Compounds on Cell Growth and Lactic Acid Production:
The effect on the growth of HepG2 cells was determined by incubating cells in the presence of 0 μM, 0.1 μM, 1 μM, 10 μM and 100 μM drug. Cells (5×10 4 per well) were plated into 12-well cell culture clusters in minimum essential medium with nonessential amino acids supplemented with 10% fetal bovine serum, 1% sodium pyruvate, and 1% penicillin/streptomycin and incubated for 4 days at 37° C. At the end of the incubation period the cell number was determined using a hemocytometer. Also taught by Pan-Zhou X-R, Cui L, Zhou X-J, Sommadossi J-P, Darley-Usmer V M. “Differential effects of antiretroviral nucleoside analogs on mitochondrial function in HepG2 cells” Antimicrob. Agents Chemother. 2000; 44: 496-503. To measure the effects of compounds on lactic acid production, HepG2 cells from a stock culture were diluted and plated in 12-well culture plates at 2.5×10 4 cells per well. Various concentrations (0 μM, 0.1 μM, 1 μM, 10 μM and 100 μM) of test compound were added, and the cultures were incubated at 37° C. in a humidified 5% CO 2 atmosphere for 4 days. At day 4 the number of cells in each well was determined and the culture medium collected. The culture medium was filtered, and the lactic acid content in the medium determined using a colorimetric lactic acid assay (Sigma-Aldrich). Since lactic acid product can be considered a marker for impaired mitochondrial function, elevated levels of lactic acid production detected in cells grown in the presence of test compound would indicate a drug-induced cytotoxic effect.
ii) Effect on Compounds on Mitochondrial DNA Synthesis:
a real-time PCR assay to accurately quantify mitochondrial DNA content has been developed (see Stuyver L J, Lostia S, Adams M, Mathew J S, Pai B S, Grier J, Thamish P M, Choi Y, Chong Y, Choo H, Chu C K, Otto M J, Schinazi R F. Antiviral activities and cellular toxicities of modified 2′,3′-dideoxy-2′,3′-didehydrocytidine analogs. Antimicrob. Agents Chemother. 2002; 46: 3854-60). This assay was used in all studies described in this application that determine the effect of test compound on mitochondrial DNA content. In this assay, low-passage-number HepG2 cells were seeded at 5,000 cells/well in collagen-coated 96-well plates. Compounds were added to the medium to obtain final concentrations of 0 μM, 0.1 μM, 10 μM and 100 μM. On culture day 7, cellular nucleic acids were prepared by using commercially available columns (RNeasy 96 kit; Qiagen). These kits co-purify RNA and DNA, and hence, total nucleic acids were eluted from the columns. The mitochondrial cytochrome c oxidase subunit II (COXII) gene and the β-actin or rRNA gene were amplified from 5 μl of the eluted nucleic acids using a multiplex Q-PCR protocol with suitable primers and probes for both target and reference amplifications. For COXII the following sense, probe and antisense primers are used, respectively: 5′-TGCCCGCCATCATCCTA-3′,5′-tetrachloro-6-carboxyfluorescein-TCCTCATCGCCCTCCCATCCC-TAMRA-3′ and 5′-CGTCTGTTATGTAAAGGATGCGT-3′. For exon 3 of the β-actin gene (GenBank accession number E01094) the sense, probe, and antisense primers are 5′-GCGCGGCTACAGCTTCA-3′, 5′-6-FAMCACCACGGCCGAGCGGGATAMRA-3′ and 5′-TCTCCTTAATGTCACGCACGAT-3′, respectively. The primers and probes for the rRNA gene are commercially available from Applied Biosystems. Since equal amplification efficiencies were obtained for all genes, the comparative CT method was used to investigate potential inhibition of mitochondrial DNA synthesis. The comparative CT method uses arithmetic formulas in which the amount of target (COXII gene) is normalized to the amount of an endogenous reference (the β-actin or rRNA gene) and is relative to a calibrator (a control with no drug at day 7). The arithmetic formula for this approach is given by 2-ΔΔCT, where ΔΔCT is (CT for average target test sample−CT for target control)−(CT for average reference test−CT for reference control) (see Johnson M R, K Wang, J B Smith, M J Heslin, R B Diasio. Quantitation of dihydropyrimidine dehydrogenase expression by real-time reverse transcription polymerase chain reaction. Anal. Biochem. 2000; 278:175-184). A decrease in mitochondrial DNA content in cells grown in the presence of drug would indicate mitochondrial toxicity.
iii) Electron Microscopic Morphologic Evaluation:
NRTI induced toxicity has been shown to cause morphological changes in mitochondria (e.g., loss of cristae, matrix dissolution and swelling, and lipid droplet formation) that can be observed with ultrastructural analysis using transmission electron microscopy (see Cui L, Schinazi R F, Gosselin G, Imbach J L. Chu C K, Rando R F, Revankar G R, Sommadossi J P. Effect of enantiomeric and racemic nucleoside analogs on mitochondrial functions in HepG2 cells. Biochem. Pharmacol. 1996, 52, 1577-1584; Lewis W, Levine E S, Griniuviene B, Tankersley K O, Colacino J M, Sommadossi J P, Watanabe K A, Perrino F W. Fialuridine and its metabolites inhibit DNA polymerase gamma at sites of multiple adjacent analog incorporation, decrease mtDNA abundance, and cause mitochondrial structural defects in cultured hepatoblasts. Proc Natl Acad Sci USA. 1996; 93: 3592-7; Pan-Zhou X R, L Cui, X J Zhou, J P Sommadossi, V M Darley-Usmar. Differential effects of antiretroviral nucleoside analogs on mitochondrial function in HepG2 cells. Antimicrob. Agents Chemother. 2000, 44, 496-503). For example, electron micrographs of HepG2 cells incubated with 10 μM fialuridine (FIAU; 1,2′-deoxy-2′-fluoro-1-D-arabinofuranosly-5-iodo-uracil) showed the presence of enlarged mitochondria with morphological changes consistent with mitochondrial dysfunction. To determine if compounds promoted morphological changes in mitochondria, HepG2 cells (2.5×10 4 cells/mL) were seeded into tissue cultures dishes (35 by 10 mm) in the presence of 0 μM, 0.1 μM, 1 μM, 10 μM and 100 μM test compound. At day 8, the cells were fixed, dehydrated, and embedded in Eponas described previously. Thin sections were prepared, stained with uranyl acetate and lead citrate, and then examined using transmission electron microscopy.
Example 2
Assay for Bone Marrow Cytotoxicity
Primary human bone marrow mononuclear cells were obtained commercially from Cambrex Bioscience (Walkersville, Md.). CFU-GM assays were carried out using a bilayer soft agar in the presence of 50 units/mL human recombinant granulocyte/macrophage colony-stimulating factor, while BFU-E assays used a methylcellulose matrix containing 1 unit/mL erythropoietin (see Sommadossi J P, Carlisle R. Toxicity of 3′-azido-3′-deoxythymidine and 9-(1,3-dihydroxy-2-propoxymethyl) guanine for normal human hepatopoietic progenitor cells in vitro. Antimicrob. Agents Chemother. 1987; 31: 452-454; Sommadossi, J P, Schinazi, R F, Chu, C K, and Xie, M Y. Comparison of Cytotoxicity of the (−) and (+) enantiomer of 2′,3′-dideoxy-3′-thiacytidine in normal human bone marrow progenitor cells. Biochem. Pharmacol. 1992; 44:1921-1925). Each experiment was performed in duplicate in cells from three different donors. AZT was used as a positive control. Cells were incubated in the presence of the compound for 14-18 days at 37° C. with 5% CO 2 , and colonies of greater than 50 cells are counted using an inverted microscope to determine IC 50 . The 50% inhibitory concentration (IC 50 ) was obtained by least-squares linear regression analysis of the logarithm of drug concentration versus BFU-E survival fractions. Statistical analysis was performed with Student's t test for independent non-paired samples.
Example 3
Cytotoxicity Assay
The toxicity of the compounds was assessed in Vero, human PBM, CEM (human lymphoblastoid), MT-2, and HepG2 cells, as described previously (see Schinazi R. F., Sommadossi J.-P., Saalmann V., Cannon D. L., Xie M.-Y., Hart G. C., Smith G. A. & Hahn E. F. Antimicrob. Agents Chemother. 1990, 34, 1061-67). Cycloheximide was included as positive cytotoxic control, and untreated cells exposed to solvent were included as negative controls. The cytotoxicity IC 50 was obtained from the concentration-response curve using the median effective method described previously (see Chou T.-C. & Talalay P. Adv. Enzyme Regul. 1984, 22, 27-55; Belen'kii M. S. & Schinazi R. F. Antiviral Res. 1994, 25, 1-11).
Results:
Cytotoxicity (IC 50 , μM) in:
PBM
CEM
Vero
>100 (20.7)
85.1
100 (45.3)
Example 4
HCV Replicon Assay 1
Huh 7 Clone B cells containing HCV replicon RNA would be seeded in a 96-well plate at 5000 cells/well, and the compounds tested at 10 μM in triplicate immediately after seeding. Following five days incubation (37° C., 5% CO 2 ), total cellular RNA was isolated by using versaGene RNA purification kit from Gentra. Replicon RNA and an internal control (TaqMan rRNA control reagents, Applied Biosystems) were amplified in a single step multiplex Real Time RT-PCR Assay. The antiviral effectiveness of the compounds was calculated by subtracting the threshold RT-PCR cycle of the test compound from the threshold RT-PCR cycle of the no-drug control (ΔCt HCV). A ΔCt of 3.3 equals a 1-log reduction (equal to 90% less starting material) in Replicon RNA levels. The cytotoxicity of the compounds was also calculated by using the ΔCt rRNA values. (2′-Me-C) was used as the control. To determine EC 90 and IC 50 values 2 , ΔCt: values were first converted into fraction of starting material 3 and then were used to calculate the % inhibition.
REFERENCES
1. Stuyver L et al., Ribonucleoside analogue that blocks replication or bovine viral diarrhea and hepatitis C viruses in culture. Antimicrob. Agents Chemother. 2003, 47, 244-254.
2. Reed I J & Muench H, A simple method or estimating fifty percent endpoints. Am. J. Hyg. 27: 497, 1938.
3. Applied Biosystems Handbook Rev. D, 5/2005
Results:
HCV
Conc
HCV
St.
DCt
%
rRNA
St.
DCt
% inhib.
[nM]
Ct
Average
Dev.
HCV
Inhit
Ct
Average
Dev.
rRNA
rRNA
EC 50
EC 90
CC 50
100
30.3
30.5
0.3
7.3
99.4
19.0
19.0
0.2
−1.0
−95.2
>100 nM
30.5
18.8
30.8
19.2
33
29.2
28.9
0.4
5.7
98.0
19.2
19.1
0.1
−0.8
−75.6
29.1
19.2
28.4
19.1
10
27.0
26.8
0.2
3.6
91.7
19.2
19.0
0.1
−0.9
−89.1
7.7 nM
9.9 nM
26.9
18.9
26.6
19.0
3
22.6
22.8
0.4
−0.4
−33.8
19.2
19.2
0.2
−0.8
−74.8
23.2
19.3
22.6
18.9
Example 5
Bioavailability Assay in Cynomolgus Monkeys
The following procedure can be used to determine whether the compounds are bioavailable. Within 1 week prior to the study initiation, a cynomolgus monkey can be surgically implanted with a chronic venous catheter and subcutaneous venous access port (VAP) to facilitate blood collection and can undergo a physical examination including hematology and serum chemistry evaluations and the body weight recording. Each monkey (six total) receives compound at a dose level of 2-20 mg/kg, either via an intravenous bolus (3 monkeys, IV), or via oral gavage (3 monkeys, PO). Each dosing syringe is weighed before dosing to gravimetrically determine the quantity of formulation administered. Urine samples are collected via pan catch at the designated intervals (approximately 18-0 hours pre-dose, 0-4, 4-8 and 8-12 hours post-dosage) and processed. Blood samples are collected as well (pre-dose, 0.25, 0.5, 1.2, 3.6, 8, 12 and 24 hours post-dosage) via the chronic venous catheter and VAP or from a peripheral vessel if the chronic venous catheter procedure should not be possible. The blood and urine samples are analyzed for the maximum concentration (Cmax), time when the maximum concentration is achieved (Tmax), area under the curve (AUC), half-life of the dosage concentration (TV,), clearance (CL), steady state volume and distribution (Vss) and bioavailability (F).
Example 6
Effect of HCV Protease Inhibitors on Selected Human Proteases
HCV protease inhibitors have demonstrated great antiviral potency in addition to interesting toxicities associated with inhibition of host proteases. In an effort to circumvent similar toxicities, new protease inhibitors were evaluated for inhibition of a panel of important human proteases. The enzymes tested are Elastase (Neutrophil), Plasmin, Thrombin, and Cathepsin S.
Neutrophil elastase (or leukocyte elastase) also known as ELA2 (elastase 2) is a serine protease in the same family as chymotrypsin and has broad substrate specificity. Secreted by neutrophils during inflammation, one of its primary roles is to destroy bacteria in host tissue. (Belaaouaj et al, Science 289 (5482): 1185-8).
Plasmin is a serine protease derived from the conversion of plasminogen in blood plasma by plasminogen activators (Collen, D. Circulation, 93, 857 (1996). This enzyme (EC 3.4.21.7) degrades many blood plasma proteins, most notably, fibrin clots. Plasmin is also involved in several pathological and physiological processes such as inflammation, neoplasia, metastasis, wound healing, angiogenesis, embryogenesis and ovulation (Vassalli, J. D. et al, J. Clin. Invest. 88, 1067 (1991).
Thrombin is a coagulation protein in the blood stream that has many effects in the coagulation cascade, the last enzyme in the clotting cascade. It is a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, as well as catalyzing many other coagulation-related reactions.
Cathepsin S, a member of the peptidase C1 family, is a lysosomal cysteine protease that may participate in the degradation of antigenic proteins to peptides for presentation on MHC class II molecules, therefore it is key to immune response. The encoded protein can function as an elastase over a broad pH range.
Materials:
Victor 3 Plate reader (Perkin Elmer)
Clear 96 well Plates (Phenix Research)
Black 96 well Plates (Perkin Elmer)
RNase and Dnase pure water
Methods:
Elastase (Human Neutrophil (Cat #16-14-051200 Athens Research and Technology, Athens Ga.)): Reactions were conducted in a sample volume of 100 μL per well in a clear 96 well plate. A 2× assay buffer was made containing 200 mM Tris-HCl (pH 7.5), 150 mM NaCl and 50% glycerol. For each sample 50 μL 2× assay buffer was added to each well. The substrate (MeOSuc-AAPV-pNA, Chromogenic Substrate, Cat # P-213, Enzo Life Sciences, Plymouth Meeting, Pa.; 50 mM stock in DMSO) was added to a final concentration of 1 mM. The drug dilutions were added (25 μL) at 4× concentrations in water. Finally, a mixture was made of 1 μL elastase and 22 μL water for each sample and 23 μL was added to each well. The samples were incubated at room temperature for 30 min. The absorbance at 405 nM was read on the Victor 3 plate reader. All samples were tested in duplicate. Results are shown as blank adjusted (no Elastase) percentages of maximum absorbance, which was given by a no inhibitor control.
Plasmin and Thrombin(Sensolyte RH110 Plasmin Activity Assay Kit and Sensolyte Thrombin Activity Assay Kit (Anaspec)): Reactions were conducted in a sample volume of 100 μL per well in a black 96 well plate. Protocol A was followed from the kit insert where the 2× assay buffer was diluted 1:1 with deionized water. Included in each assay were a positive control (diluted enzyme and no test compound), inhibitor control (contains diluted enzyme and plasmin inhibitor; component E from the kit or thrombin inhibitor; N-α-NAPAP synthetic inhibitor) and substrate control (assay buffer and substrate). Vehicle and autofluorescence controls were also performed. Drug dilutions were added (10 μL) at 10× concentrations in assay buffer. The enzyme was added at 40 μL/well at a concentration of 0.25 μg/mL (plasmin) and 1 μg/mL (thrombin) to all wells except the substrate control. Finally, 50 μL assay buffer containing substrate was added to each well. The substrate was added to a final concentration of 50 nM (plasmin) or 20 nM (Thrombin). The samples were incubated at room temperature for 30 min. The fluorescence intensity was read on the Victor 3 plate reader at Ex/Em=490 nm/520 nm. All samples were tested in duplicate. Results are shown as substrate control adjusted percentages of maximum absorbance, which was given by the positive control.
Cathespsin S (Sensolyte Cathepsin S Activity Assay Kit (Anaspec)): Reactions were conducted in a sample volume of 100 μL per well in a black 96 well plate. Protocol A was followed from the kit insert where DTT was added to assay buffer to yield a 5 μM concentration. Included in each assay were a positive control (diluted enzyme and no test compound), inhibitor control (contains diluted enzyme and plasmin inhibitor; component E or thrombin inhibitor; N-α-NAPAP synthetic inhibitor) and substrate control (assay buffer and substrate). Vehicle and autofluorescence controls were also performed. Drug dilutions were added (10 μL) at 10× concentrations in assay buffer. The cathepsin S was added at 40 μL/well at a concentration of 2.5 μg/mL to all wells except the substrate control. Finally, 50 μL of assay buffer containing substrate was added to each well. The substrate was added to a final concentration of 16 nM. The samples were incubated at room temperature for 30 min. The fluorescence intensity was read on the Victor 3 plate reader at Ex/Em=490 nm/520 nm. All samples were tested in duplicate. Results are shown as substrate control adjusted percentages of maximum absorbance, which was given by the positive control.
Example 7
Activity of Compounds Versus Hepatitis C Virus NS3/4A WT and Mutant Protease
The HCV NS3/4A protease assays were carried out using a SensoLyte® 490 HCV Protease Assay Kit using fluorescence resonance energy transfer (FRET) peptide (AnaSpec).
While the foregoing specification teaches the principles of the present invention, with examples provided for the purpose of illustration, it will be understood that the practice of the invention encompasses all of the usual variations, adaptations and/or modifications as come within the scope of the following claims and their equivalents.
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The present invention is directed to compounds, compositions and methods for treating or preventing HCV viral infections in human patients or other animal hosts.
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RELATED U.S. APPLICATION
This application is a continuation of U.S. patent application Ser. No. 13/405,495 filed Feb. 27, 2012, which claims the benefit of U.S. Provisional Application No. 61/466,588 filed Mar. 23, 2011.
FIELD OF THE INVENTION
The present invention relates to containers for storage of liquids, granular materials and the like, and methods and apparatuses for forming the same. More particularly, the container of the present invention is a single piece blow-molded plastic container formed in a multi-sided configuration with modified corner radii, utilizing a smaller volume of raw material to obtain volumes and strength equivalent to the prior art.
DESCRIPTION OF THE RELATED ART
Blow-molded plastic bottles are well known for use for holding a wide variety of liquids such as milk, water and juice. The same types of containers may be used for granular materials. Containers of this type are manufactured in a variety of sizes, conventionally formed of a variety of thermoplastic materials.
Typical of these containers are those disclosed in U.S. Pat. No. 6,527,133, issued to McCollum et al.; U.S. Pat. No. 4,805,793, issued to Brandt et al.; and U.S. Pat. No. 6,237,792, issued to Skolnicki et al.
Containers of this type are relatively thin-walled, and are generally square or rectangular in cross-section, feature a molded handle, and typically have a finished weight of over 60 grams. Such weight of material is essential to maintaining sufficient strength for the container to withstand the industrial filling process, in particular, the loads imposed for securement of a closure, such as a cap, lid or screw top to the spout on the top of the container. FIGS. 1A , 1 B, 1 C and 1 D show top, front, side and bottom views, respectively of blow-molded containers formed according to the prior art. The typical prior art container is depicted in FIGS. 1A-1D incorporates a top 102 , a bottom 104 and spout 120 . Top 102 and bottom 104 are interconnected by sidewalls 106 , and includes a handle 122 . In the prior art, a relatively acute transition occurs at the top corner 130 of the top 102 of the container, where the top 102 joins the lower circumference of the spout 120 . Then, when the top 102 joins the sidewall 106 , a second relative abrupt transition occurs at upper corner 124 , generating a comparatively sharp angle between the top 102 and the sidewall 106 . Transitioning to the bottom section of the prior art container, a first intermediate corner 126 creates a first transition between the sidewall 106 and the bottom 128 of the container. A bottom corner 128 completes the transition between the sidewall 106 and bottom 104 . The combination of the corner transitions at intermediate corner 126 and bottom 128 , coupled with the substantial distance between intermediate corners 126 and 128 demand a substantial distribution of material to the bottom section of the container to provide the necessary strength. The same problem is evident at the top of the container 102 , where the top 102 of the container joins the sidewall 106 at upper corner 124 . These multiple spaced apart transitions often result in excessively thin walls at the transitions, thereby weakening the container.
More recently, containers have been created which incorporate ribs and other design features in the upper sidewalls of the container to increase mechanical strength, well at the same time decreasing the wall thickness of the finished container. By reducing the overall thickness of the container, substantial savings in materials cost can be realized. Newer containers utilizing these design methodologies have resulted in reductions in material required for each container, and corresponding reductions in material cost, of between five and seven percent. Such reductions in the typical production environment can result in substantial cost savings over time.
The existing containers, however, suffer from important limitations. Particularly, as known in the prior art, the manufacture of thin-walled thermoplastic containers utilizing the blow-molding techniques can create unacceptably thin wall dimensions near the top and bottom of the containers, where the tops and bottoms of the containers join the side walls. Excessive thinning in these areas weakens the overall container and reduces its ability to withstand the forces typically imposed during the filling process. To insure that sufficient wall thickness remains in these vital sections, the current containers require a minimum of approximately fifty-eight to sixty grams in weight. A need exists, therefore, for a container design and method of manufacture, which permits more even distribution of thermoplastic material throughout the wall of the container, while allowing significant reductions in the amount of material required to produce the container.
SUMMARY OF THE INVENTION
In summary, a thin-walled container in accordance with the present invention is formed having sidewalls, a bottom, a top having a neck, a handle, and a spout. The container has eight sides, and a smoothly tapered radius between the spout and the sidewall. To form the container, specialized round tooling is utilized in the die and its associated mandrel to achieve more even distribution of the thermoplastic material during the molding process. The resulting container displays a more efficient distribution of the materials along the sidewalls, top and bottom of the container, typically at a weight of fifty-two grams or less.
It is an object of the present invention, therefore, to provide a thin-walled container having an extremely light weight. Further, it is an object of the present invention to provide a thin-walled container having six or more sides and a specially radiused transition between the spout and sidewall of the container.
It is another object of the present invention to position the handle of the container to improve venting of the interior of the container during the pouring process.
It is another object of the present invention to provide a system for manufacturing the same volume of container as taught in the prior art, while maintaining the necessary structural integrity of the container to withstand the industrial filling process.
It is a further object of the present invention to provide and improved container having the same volume and fitting in the same standard case as taught in the prior art.
These, and other objects of the invention, will be apparent from the associated drawings and description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A us a top view of a prior art container, constructed according to the methods of the prior art.
FIG. 1B is a front view of a prior art container, constructed according to the methods of the prior art.
FIG. 1C is a side view of a prior art container, constructed according to the methods of the prior art.
FIG. 1D is a bottom view of a prior art container, constructed according to the methods of the prior art.
FIG. 2A is a front view of a first embodiment of the present invention.
FIG. 2B is a side view of a first embodiment of the present invention.
FIG. 2C is a bottom view of a first embodiment of the present invention.
FIG. 2D is an alternate bottom view of a current embodiment of the present invention.
FIG. 2E is an additional bottom view of another variant of a current embodiment of the present invention.
FIG. 3A is a front view of the present invention.
FIG. 3B is a side view of another embodiment of the present invention.
FIG. 3C is a top view of another embodiment of the present invention.
FIG. 3D is a bottom view of another embodiment of the present invention.
FIG. 4 is a diagram showing a die and mandrel according to an embodiment of the present invention.
FIG. 5 is a diagram showing a parison and a mold according to an embodiment of the present invention.
FIG. 6 is a top view of embodiments of the present invention held in a standard dairy crate.
FIG. 7A is a top view of an embodiment of the present invention;
FIG. 7B is a side view of an embodiment of the present invention;
FIG. 7C is a side view of an embodiment of the present invention;
DESCRIPTION OF THE PREFERRED EMBODIMENT
The description which follows will be best appreciated by reference to the accompanying drawings. Although the invention is described in conjunction with the drawings, and a plurality of preferred embodiments is described, it will be appreciated that these descriptions are not intended to limit the invention to those embodiments. The invention includes a variety of alternatives, modifications and equivalents which may be included within the spirit and scope of the invention as defined by the appended claims.
The invention will be better understood by a full appreciation of the process of manufacture typically used in the art. A conventional blow-molding machine includes a loading station where pelletized thermoplastic material, such as polyethylene, may be introduced into a hopper or feed bin. The hopper, in turn, feeds the pelletized or granular thermoplastic materials, which is at room temperature, to a heater/drive system. Such a system typically includes a screw drive provided with one or more heating mechanisms or elements which gradually raise the temperature of the thermoplastic material to approximately 365° F. Once the material has attained this temperature, the material liquefies and becomes taffy-like in its consistency. The material is then introduced into the mold through a die and mandrel combination, whereby the thermoplastic material is evenly distributed in the mold. The blob of thermoplastic material which forms as it is extruded through the gauged opening between the die and mandrel is called a parison. Once the parison is formed the mold is closed around the parison possibly imparting the general shape of the interior of the mold onto the parison. This aids in distributing the material of the parison evenly throughout the interior of the mold when the mold is pressurized. The mold is then pressurized via the blow pin thereby forcing the parison to expand throughout the interior of the walls of the mold, and imparting to the material the finished shape of a container. To facilitate the molding process, the mold walls are cooled to approximately 30° to 40° F., to restore the liquefied thermoplastic material to solid state. Once the part has formed, the mold is opened and the part is removed from the mold.
Turning now to FIGS. 2A-2E , a first embodiment of a container formed according to the present invention is disclosed. Container 10 consists of a top section 12 , a bottom 14 and a plurality of sidewalls. Eight sidewalls alternate in dimension, four being long sidewalls 16 and four being short sidewalls 18 . The top section 12 is configured with a spout 20 having an opening 21 by which material may be introduced into the interior of the container 10 . The container is molded as a single piece, and includes a handle 22 which is hollow and permits liquid and air to pass inside it. Preferably, the handle is configured adjacent to a short sidewall 18 , so that when the container is held for pouring, the center of mass is concentrated along the axis which intersects both the handle and the opposing short sidewall of the container.
In a first embodiment, the height of the container 10 is measured from the bottom of the container to the bottom of the spout is approximately 9.231 inches, for a container having a volume of approximately 234 cubic inches, essentially a one-gallon container. In this embodiment, a radius transition 24 is formed between the upper limit of the sidewalls 16 , 18 and spout 20 . Preferably, the radius R has a dimension of approximately three inches, thereby providing a smooth transition between the sidewalls 16 , 18 and spout 20 of the container 10 in comparison to the prior art. This area of transition may include one or more ribs 28 to provide additional strength to the container. The container 10 is blow-molded, and includes a single piece thin wall construction. The sidewalls, when viewed from above, form a generally octagonal configuration as seen in top or bottom plan views. The container 10 includes a bottom 14 which is interconnected to the sidewalls 16 and 18 and has a plurality of ribs 30 . In one example, the radius transition 24 in between the sidewalls 16 , 18 and the spout 20 has a radius of approximately 3″ and a transition section length of about 2.5″ in a container having an overall height of approximately 10″.
A second embodiment of the invention as disclosed in FIGS. 3A and 3B , which does not include the ribs 30 but does include the same upper radius transition 24 . Containers of either configuration may be formed with one or more volume control inserts 32 molded into one or more sides of the container to adjust the total internal volume of the container 10 .
Turning now to first embodiment of the invention as shown in FIGS. 2A-E , it will be appreciated that the top section 12 of the container 10 incorporates an upper radius transition of radius R between the bottom of the spout 20 and the top of sidewalls 16 and 18 . The absence of the sharp transitions between the bottom of the spout and the container top, and the top of the sidewall in the container top results in increased strength while allowing for even distribution of the thermoplastic material, eliminating the sharp transitions of the prior art. The inclusion of rib 28 imparts additional strength to this vital section of the container.
Likewise, the intermediate corners 34 and bottom corners 36 are positioned closer than the corresponding transition corners in the prior art, resulting in a more even distribution of the thermoplastic material at those critical locations. As shown in FIGS. 2C-2E , a variety of methods may be adopted for placement of strengthening ribs 30 on the bottom of the container to impart a higher degree of rigidity, utilizing a thinner bottom wall section than required by the prior art. A variety of planiforms may be selected as depicted in FIGS. 2C-2E , each of which forms the desired function of imparting the necessary strength to the bottom of the container.
FIGS. 3A-3D show a second embodiment of the invention, where the bottom 44 of the container 38 is provided with a plurality of impressions 40 , 42 which may facilitate stacking of containers 38 . FIGS. 3A , B, C and D show a first side view, a second side view, a top view and a bottom view, respectively of an embodiment of the invention showing impressions 40 , 42 cast into the bottom 44 of container 38 .
It will be further appreciated that additional strength may be obtained by multiplying the number of sidewalls as shown in FIGS. 2C and 3C . In each of the embodiments therein depicted, it will be appreciated that the container has eight sidewalls. The utilization of multiple sidewalls decreases the angles between the sidewalls, and the gentler radiuses therein incorporated allows for more even distribution of the thermoplastic material during the molding process. Embodiments of this disclosure have sidewalls arranged as opposing pairs where the distance between pairs of sidewalls is arranged so that two pairs of sidewalls are separated by a first distance and a third pair of sidewalls are separated by a second distance. The ratio of the first distance to the second distance is between about 1:1 to about 1:1.10, with the preferred ratio equal to about 1:1.06.
A further advantage of incorporation of the upper radius transition 24 is the improved pouring characteristics of the container. In a prior art, the sharp transitions between the top of the container and the spout and the upper part of the handle and the top of the container results in periodic difficulty in pouring from the container as liquid blocks movement of the contents of the container away from the handle, causing the contents of the container to pour in spurts, rather than in a continuous stream as air is admitted past the liquid. By utilization of the extended upper radius transition of the present invention, the contents of the container flow easily. In addition, the handle section is designed to be hollow and allow air to escape during poring due to its proximity to the spout to thereby mitigate splashing as liquid is poured from the container. It is also noted that the curved nature of the upper radius transition between the sidewalls and the spout permits the handle to be attached higher on the container proximate to the spout and have a smaller hole between the handle and the container, thereby improving the pouring characteristics as mentioned above and permitting the container to contain a greater volume of material.
Improved characteristics of containers produced according to embodiments of this invention are due at least in part to improvements to the equipment used to produce the containers, in particular the die and mandrel combination and the shape and size of the mold. FIG. 4 shows a cross-sectional view of an extrusion mechanism 50 according to an embodiment of this invention. This extrusion mechanism 50 operates as part of a blow molding machine, where the extrusion mechanism 50 positions a circular mandrel 54 having an air passage 56 in a circular die 60 so that a predetermined die gap 66 exists between the mandrel 54 and the die 60 a predetermined die angle 64 . Thermoplastic material is forced into the extrusion mechanism 50 in the direction indicated by arrow “A”, flows around the mandrel 54 and through the die gap 66 to form a parison. A parison is typically a hollow tube or bulb of semi-molten material which extends past the mandrel into the volume which will be the cavity of the mold. Once the desired parison is created, the mold (not shown) closes around the parison so that air can be introduced into the air passage 56 to inflate the parison to fill the enclosing mold. The size and shape of the die angle 64 and die gap 66 with respect to the mandrel 54 can determine the exact proportions of the parison. In this case the die 60 and mandrel 54 are both circular. The first parameter is the die angle 64 which measures the angle of the die 60 with respect to the mandrel 54 . Die angles 64 can range from 0° to 30° or more particularly about 15°-18°. Using a die angle 64 of less than 30° allows the die gap 66 to be smaller. In the case of one gallon containers, a die gap 66 of between about 0.001″ and about 0.025″ or more particularly about 0.006″ produces a parison with the desired shape and size when the appropriate amount of material is forced through the die/mandrel combination.
In addition to the shape due to the die angle 64 and die gap 66 , as shown in FIG. 5 , a parison can change shape when the mold is closed. FIG. 5 shows a cross-sectional view of a parison 70 with a hollow core 72 inside a mold cavity 74 formed by the two parts of a two-part mold 76 , 78 according to an embodiment of this invention. The parison 70 has elongated and formed an elliptical shape following closure of the mold halves 76 , 78 . Embodiments of this invention use the elliptical shape of the parison 70 in combination with improved design of the mold cavity 74 to improve the quality of the finished container. By forming a container with an elongated or diamond shape, shown in FIG. 5 , the walls of the mold 88 can be kept at a substantially small similar distance from the parison 70 . Replacing corners with short sidewall sections 80 , 82 , 84 and 86 and shaping the mold to mirror the shape of the parison improves the structural rigidity of the resulting blow molded container while maintaining overall container strength using less material. In addition, this design helps to avoid dented corners as the resulting container is used, thereby enhancing its appearance. The elongated parison 70 fits the mold cavity 74 more closely than a mold cavity having four symmetric sides. Shaping the interior of the mold to form an elongated shape similar to the parison 70 , where the distance from the parison to the mold wall 88 is substantially equal causes the parison 70 to mold to the interior shape of the mold when the interior of the parison is pressurized. Having the interior of the mold closely mirror the elongate shape of the parison will provide the strongest container for the least amount of material by distributing the material evenly and thereby providing uniform wall thickness. Typical gallon containers manufactured by blow molding can use a minimum of 58 grams of thermoplastic material to form successfully, with 61-64 grams being typical in manufacturing operations. Embodiments of this invention can manufacture gallon containers with desirable strength and appearance using less than about 55 grams of thermoplastic materials, or more preferably less than about 52 grams of thermoplastic material.
FIG. 6 shows a top view of embodiments of this invention held in a standard dairy crate. Dairy crates are cases constructed to hold multiple containers so that dairy crates with full containers may be stacked without damage to the containers or contents. Dairy crates are manufactured in standard configurations and it is an advantage of embodiments of this invention that these embodiments fit in a standard dairy crate. As shown in FIG. 6 , a standard 4-gallon dairy crate 51 holds four 1-gallon containers 52 made in accordance with embodiments of this invention.
FIG. 7A shows a top view an embodiment of this invention with the 6″×6″ footprint of the container indicated. FIGS. 7B and 7C show side views of an embodiment of this invention showing how the container can fit in a space with height 10.040″. As can be seen from FIGS. 7A , 7 B and 7 C, containers constructed according to disclosed embodiments can fit in a 6″×6″×10.040″ cube. Fill percentage is the percentage of the volume of a minimal enclosing cube that is contained within the container. Disclosed embodiments have a fill percentage greater than about 60%. More particularly, containers constructed according to disclosed embodiments fill about 64.7% of the 6″×6″×10.040″ cube required to hold a container. Disclosed embodiments provide a fill percentage in excess of 60%, which permits more material to be stored in containers in a given volume while maintaining ease of use features such as handle placement.
The above-described embodiments have been described in order to allow easy understanding of the present invention and do not limit the present invention. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structure as is permitted under the law.
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An improved lightweight container incorporates a thinner wall structure in an essentially octagonal container having a bottom member, a plurality of sidewalls, a spout, an upwardly converging neck member coupling the sidewalls of the spout, a handle molded into the container and a radiused transiting section between the sidewalls and the spout which eliminates weakened corner sections and improves overall strength to weight ratios.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to X-ray tables and more particularly to tiltable tables
2. Description of the Prior Art
In so-called tilting type X-ray tables the table body is pivotally connected to a base or pedestal part so that it can be tilted in either direction from its normal position in which the patient-supporting surface is horizontal. This tilting permits a patient to be examined, in any angular table body position between two vertical positions. X-ray tables of this type are well known. Such a table typically includes a movable tower assembly which supports an X-ray tube within the body. The tower also supports radiation responsive devices, such as, a spot filmer, an image tube, and cameras for viewing the image tube output. These devices are usually above the patient supporting top of the table.
The tower assembly includes a column or tower within a forwardly extending portion that extends into the body of the table and underneath the top. This tower extension is mounted on carriage for movement horizontally in a direction transverse to the length of the table. The carriage is in turn supported on suitable ways in the body of the table for movement lengthwise of the table proper. The tower projects from the rear of the table body and supports a further carriage for movement towards and from the table proper. The further carriage carries the radiation detection device which is also movable throughout substantially the entire length of the table.
The movement of a tower assembly should be smooth and relatively effortless. It also should be linear to maintain accurate and consistent spatial relationship among a patient, the table's X-ray tube and the supported imaging devices. If the movement of the tower assembly and the table top is to be consistent and linear the table must be rigid and accurately manufactured.
Conventionally, tables have been constructed in which an upper frame and connected or integrally formed track elements supported the tower assembly. These track elements provided flat track surfaces which were in planes either parallel or perpendicular to the plane of the patient supporting surface.
The condition when smooth tower assembly movement is most difficult to achieve is when the table is tilted to θ vertical orientation. Since the tower carriage movement is vertical rather than horizontal, both the tower and counterweights of equal mass within the table must move vertically and easily. When the table is vertical the mass of the tower assembly, most of which is external of the table body, applies twisting forces to the tower assembly guide tracks and rollers. The resultant of these forces is a plane which is skewed with respect to the plane of the table top.
With prior tables, tower assembly rollers have been positioned such that some had their axes parallel to the table top while others had their axes perpendicular to the table top. Since the forces applied are skew with respect to the plane of the table top the forces applied to the rollers were not purely radial, but rather have significant axial vectors. This skewed force application caused the rollers to perform poorly and wear excessively.
Prior to the present invention various methods of constructions have been employed for supporting the column or tower in the table, but none are entirely satisfactory.
SUMMARY OF THE INVENTION
The present invention provides a novel and improved X-ray table, preferably of the tilting type pivotally supported on a base or pedestal, cantilevered thereon, if desired, for movement from one vertical position to the opposite vertical position and which employs cylindrical table ways for supporting the column or tower for movement lengthwise of the table body.
Rollers for support of the tower assembly are provided in clusters of 4. The rollers of each cluster are uniformly spaced, circumferentially speaking, to provide two pairs of diametrically opposed rollers. One roller of each pair is eccentrically mounted so that each roller pair can be independently adjusted to provide a precise and desired preloading of the rollers which are in the form of rolling element bearings.
The use of the cylindrical ways with the clusters of rollers provides a major advantage over the art. The advantage is, the rollers are positioned such that when the table is in a vertical orientation, the skewed resultant forces applied to the rollers by the weight of the tower are imposed radially on those rollers which bear the load. Expressed another way, the rollers are positioned such that their axes of rotation are neither parallel nor perpendicular to the plane of the table top but rather parallel or perpendicular to the plane of the resultant of forces applied to the rollers. This construction provides smooth, trouble-free bearing support for the tower in all table orientations and bearing life is extended.
The invention resides in certain constructions and combinations and arrangements of parts and further objects and advantages of the invention will be hereinafter referred to and others will be apparent from the following description of the preferred embodiment of the invention depicted in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a 90--90 X-ray table assembly embodying the present invention;
FIG. 2 is a fragmentary plan view of the body of the table with the patient supporting top removed and parts broken away;
FIG. 3 is a fragmentary sectional view, with parts in elevation, approximately on the line 3--3 of FIG. 2 and looking towards the right, that is, in the direction of the foot of the table;
FIG. 4 is a sectional view, with parts broken away and parts in elevation, approximately on the line 4--4 of FIG. 2;
FIG. 5 is a front elevational view of the body of the table, with parts broken away and parts in elevation;
FIG. 6 is a fragmentary sectional view approximately on the line 6--6 of FIG. 5;
FIG. 7 is a sectional view of the body of the table approximately on the line 7--7 of FIG. 5; and
FIG. 8 is a sectional view approximately on the line 8--8 of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings FIG. 1 is a perspective view of an X-ray table of the 90--90 type embodying the present invention which is concerned primarily with the construction of the "tub" or body part of the table proper. The X-ray table is designated generally by the reference character T and comprises a table proper designated generally by the reference character A which includes a body B having a patient supporting top C. The table A is pivotally supported on a base part or pedestal D only a part of which is shown. The table A is cantilevered from the rear part of the pedestal D.
In the depicted table A the X-ray tube is in a holder F (FIG. 3) within the body of the table on a column or tower carriage G transversely movable of the table body on ways 10, 12 forming part of a carrier H movable longitudinally of the table body on ways 14, 16 in the table body. The tower carriage G extends rearwardly from the table body and carries, on its outwardly projection, a tower or column J which in turn supports a carriage K for vertical movement along the tower. The carriage K in turn supports a radiation detector carrier L movable transversely of the table proper A.
The particular construction of the X-ray table T, other than the way the column or tower carriage, or more particularily the carrier H, is supported in the table for movement lengthwise thereof forms no part of the present invention and may be of any commercial or known construction. The particular construction of the body of the table herein disclosed is the subject of a patent application of William H. Amor entitled "X-ray Table" and filed on even date herewith.
The four vertical front, rear, head end and foot end sides 20, 22, 24, 26 of the table B are constructed as sub-assemblies and then placed in a suitable fixture or jig and welded together. The bottom 28 (FIG. 3) is subsequently welded to the lower parts of the vertical sides of the table. After installation of the tower carriage ways 14, 16 and the other parts of the table located within the body B the table top C is installed.
The front side 20 of the table B comprises an outside sheet metal member 40 and an inside sheet metal member 42 commonly referred to as the front side, outside the inside skins, respectively. The outside member 40 forms the front outside of the table. The front outside skin has a short vertical flange 44 along its upper edge extending upwardly at right angle from a rather narrow horizontal panel 46 formed integral with a upper edge of rather narrow vertical panel 48. At the lower edge of panel 48 the member 40 bends horizontally to form a narrow horizontal panel 50 and then downwardly at right angles to the panel 50 to form a rather wide vertical panel 52 then inwardly at right angles to the panel 52 to form a second rather narrow horizontal panel 54 then downwardly and inwardly at a slight angle to form a lower inwardly inclined or sloping panel 56. The front inside skin 42 has a horizontal panel 60 abutting the underside of panel 46 and extending slightly inwardly of vertical panel 44. From panel 60 the member 42 bends downwardly at right angles to panel 60 to form a vertical panel 62. Panel 62 extends downwardly along the inside of the front outside member 40 to slightly beyond horizontal panel 54 and terminates in a relatively narrow panel 64 inclined inwardly at an angle the same as panel 56.
Prior to assembly of the members 40, 42 with one another rod-like reinforcing or stiffening members 70 (FIG. 6.) Z-shaped in cross-section are welded to the rear side of panel 52 of member 40. The members 70, of which there are eighteen in the depicted table, are slightly inclined to the vertical and arranged in a zig zag fashion with adjacent members inclined in opposite directions. Members 70 extend from panel 50 to panel 54 of member 40 with a space between the upper ends of each pair of members. After the members 40, 42 are assembled with one another the members 70 are spot welded to panel 62 of member 42. Thereafter cylindrical members 80 are inserted in suitable through apertures in members 42 between upper end of members 70 which ends are closest together. The members 80 of which there are nine in the depicted table form supports as will be hereinafter more specifically described for the tower carriage front way 16. The openings in member 42 through which the members 80 project are slightly larger than the members 80 so that members 80 can be aligned with one another as they are welded to member 42. Later the inner ends of members 80 have horizontally aligned duplicate V-grooves machined therein for the reception of the way 14 which is an accurately formed cylindrical bar. The way 14 is fixed to the members 80 by countersunk head screws 82 threaded in tapped apertures in members 80.
The head and foot ends 24, 26 of the table body B are generally similar in construction and merely the foot end 26 is described in detail. The foot end comprises outside and inside sheet metal members 90, 92 hereinafter sometimes referred to as the head end outside and inside skin, respectively. The upper edge of the outside skin member 90 is welded to a vertical member 100 having a narrow vertical panel 102 (FIG. 8) at its upper end. From the member 100 the member 90 curves downwardly and inwardly to a planar panel 104 which is inwardly inclined, at the lower end of panel 104 member 90 curves inwardly and then downwardly and inwardly to form a planar panel 106 which terminates at the bottom of the table B. The inner skin 92 has an upper vertical panel 110 which abuts member 102. At the lower end of panel 110 member 92 bends inwardly at right angle and forms horizontal panel 112 and then downwardly at right angles to form vertical panel 114 and terminates in a horizontal panel 116 welded to the lower end of panel 104 of member 90.
Before members 90 and 92 are assembled for welding one to the other, reinforcing members are welded to the inside of panel 104 of the outside skin member 26. One of these reinforcing members is a vertical plate 120 which extends from the panel 112 to the lower end of panel 114 of the inside skin member 92, and which is located intermediate the front and rear sides of the table. The edge of the plate 120 adjacent to the panel 104 is welded thereto and the opposite edge has a plurality of tabs 122 adapted to extend through apertures 124 in the inside skin member 92. Pairs of diagonal cross braces 130, 132 and 134, 136 (FIG. 7) are also welded to the inside of the panel 104 of the outside skin member 90. Like the inner edge of the reinforcing member 120, the inner edges, that is, the edges of the cross braces not adjacent to the outside skin member 90 are provided with tabs similar to the tabs 122 of the member 120, which tabs are inserted in suitable apertures or slots in the inside skin member 92. After the reinforcing members 120, 130, 132, 134, 136 are welded to the inside of the outside skin member 104, the skin members 90, 92 are assembled together with the tabs on the aforementioned reinforcing members extending through the previously-mentioned slots in the inside skin member 92 and the upper edge of the outside skin member 90 is welded to member 100 and the upper edge of the inside skin member 92 is also welded to the member 100 thus maintaining the inside and outside skin members together.
The rear side 22 of the body 20 of the table B comprises a longitudinally extending horizontal member 150 having a flange 152 along its rear edge which extends downwardly at right angles to the horizontal part of the member 150. A rear vertical panel member 154 having a narrow flange at its upper edge is welded to the underside of the member 150 and the lower end thereof terminates in a narrow, horizontal panel 156, the inner end of which terminates in a narrow vertical panel 158. A heavy reinforcing vertical member 160 extending longitudinally of the table is welded to the outside of the member 154.
With the vertical rear sides of the body 20 of the table B assembled as mentioned above, they are assembled in a jig or fixture with the outer corner thereof aligned in such a manner that no stress is incurred in the sheet metal parts thereof. During this assembly the inner skins of the end members 24, 26 are free to float relative to the outer skins thereof because the tabs of the reinforcing members 120, 130, 132, 134 are smaller than the apertures in the inner skin members through which they project. With the parts thus assembled, the reinforcing members in the end of the table are welded to the inner skins at opposite ends and the adjoining corners of the vertical sides are welded together. When the tub or body of the table is removed from the jig or fixture, the tub or body will not warp because no stress had been set up therein. The bottom member 28 is subsequently welded to the lower edges of the vertical side members.
As previously mentioned the tower carriage front way 14 is supported or carried by members 80 at the front of the table body 20. The rear tower carriage way 16 which is also an arcuately formed cylindrical bar is connected to the table B along the rear upper inside edge thereof by a plurality of bracket members 170 of which there are seven (7) in the depicted table. The members 170 are spaced along the rear side of the table and are bolted to the underside of the mbemer 150. The members have V grooves machined in their inner sides which are inclined downwardly and outwardly for the reception of the way 16 which is bolted to the bracket by machine screws 172.
The tower carriage H is supported on the ways 14, 16 by roller assemblies M, N, O, P located at the front head and foot corners of the tower carriage and at the head and foot sides of the carriage adjacent to the rear of the table B, respectively. The front ends of the tower carrier ways 10, 12 are welded to a vertical plate 200 having a forwardly extending horizontal flange along its lower edge. A longitudinally extending vertical plate 204 is connected to the plate 200 and spaced therefrom by suitable spacers. A top roller 210 rotatably supported on a stub shaft welded to the plate 204 engages and rides upon the top of way 14. A similar roller 212 rotatably supported by a stud shaft connected to the plate 204 by an adjustable eccentric bearing engages the lower side of the way 14. Upper and lower rollers 214, 216 similar to rollers 210, 212 and connected to plate 204 at the foot end of carriage H in like manners engage and travel along the top and bottom sides, respectively, of the way 14.
The rear ends of ways 10, 12 extend through a rectangular tubular member 220 extending lengthwise of the table B adjacent to the rear side of the table. The roller assemblies O, P for supporting the carriage H on the rear way 16 are alike except for differences incident to their being connected to opposite ends of the member 220 and merely assembly O adjacent to the head end of the table B will be described.
Roller assembly O comprises four rollers 230, 232, 234, 236 spaced ninety degrees (90°) apart about the way 16. The rollers are carried on stub shafts 240, 242, 244, 246, respectively, connected to a bracket 250 connected to the head end of member 220. Rollers 230, 234 lie in a plane which makes an angle of about thirty degrees (30°) with a vertical plane through the center of way 16 from which it will be evident rollers 230, 232 engage the upper surface of the way 16. Rollers 234, 236 engage the lower surface of the way 16. The rollers 230, 236 are eccentrically connected to the bracket 250 so that they can be adjusted relative to the way 16.
From the foregoing description of the preferred embodiment of the invention it will be apparent that an X-ray table body has been provided which incorporates cylinder ways upon which the carrier for the column or tower is supported by multiple rollers at the four corners of the carrier which securely support the carrier for free movement rotative to the table body without undue play or looseness.
While the preferred embodiment of the invention has been described in considerable detail, it will be apparent that the invention can be otherwise incorporated and it is the intention to hereby cover all adaptations, modifications and uses thereof which come within the scope of the appended claims.
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An X-ray table of the tiltable type in which a tower assembly is movably carried by a table body. The tower assembly includes a mast or column that is carried by a carriage and movable relative to the carriage in a path transverse to the longitudinal extent of the table. The carriage is longitudinally movable relative to the table body. The carriage support is provided by cylindrical ways and bearing clusters each including four circumferentially spaced bearings that are arranged in diametrically opposed pairs. One bearing of each pair is eccentrically mounted for preload adjustment. The bearings of one pair are positioned such that their axes are perpendicular to the plane of resultant forces imposed on the bearings and the ways when the table is in a vertical orientation.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of my copending International Application PCT/AT01/00405, dated Dec. 27, 2001, which designated the United States and which was published in a language other than English.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a valve drive, especially for internal combustion engines of motor-powered devices, motor vehicles, or the like, having at least one cam element disposed on a driven shaft and having at least one lift valve which is displaceable by the cam element and has a valve stem, the cam element being arranged rotatably within a flexible enclosing element connected to one end of the valve stem, and further relates to a cylinder head for such a valve drive.
A valve drive of this type can be derived, for example, from WO-01/12958-A. In FIG. 7 , the cam element is arranged alongside the valve and the cylinder head (not shown) can be built somewhat lower compared with a construction represented in FIG. 5 or 6 of WO-01/12958-A.
Critical to the height of the cylinder head is the length of the slideway of the lift valve, which must not fall below a specific measure and is also partly determined by the diameter of the valve stem, since the forces acting upon the valve in the opening motion contain a lateral component.
The desmodromic valve control system dispenses with heavy valve springs and allows a lighter construction of the camshaft and valve drives, so that even the height of the cylinder head might further be reduced. However, the minimum length of the slideway precludes this. The above considerations apply generally to all internal combustion engines, since a lighter construction, for example, reduces fuel consumption. Special importance is given to the height of the cylinder head and, hence, the height of the entire engine, particularly in motor racing, where a lighter construction which economizes on structural height places the center of gravity lower down and impacts critically upon roadholding and vehicle handling.
SUMMARY OF THE INVENTION
The invention set out therefore to create a valve drive of the type stated in the introduction with improved guidance for the lift valves and achieves this by virtue of the fact that that end of the valve stem which is connected to the enclosing element is guided in the direction of displacement of the valve. The entire upper part of the valve stem is thereby able to be incorporated into the guide length dimension. It has been shown that, if the cylinder head height remains constant, more than double the guide length is attainable compared with the known valve drives. The height of the cylinder head can therefore be reduced, so that the arrangement and accommodation of the inlet and outlet duct to be operated by the lift valve emerges as the critical criterion initially to the length of the guide.
In a first preferred embodiment, it is envisaged that a holder is configured between the enclosing element and the valve stem, which holder has sliding surfaces which can be guided on cylinder-head-fixed guide surfaces.
Depending on the configuration of the holder as the connecting point between the enclosing element and the valve stem, sliding surfaces can be provided on different parts of the holder or of the valve itself. A first embodiment envisages that the holder projects over the cam element in the axial direction of the shaft and the sliding surfaces are provided on the projecting region of the holder. Even if the valve arrangement is central and well aligned, the guide of the holder is in itself sufficient to produce, axially next to the cam element, a substantial shortening of the structural height.
In a second embodiment it is envisaged that the cam element has two axially spaced cam regions and, between these, a groove disposed in extension of the sliding surfaces of the holder, the enclosing element, in the holding region for the valve stem, having a slot corresponding with the groove. In this embodiment, the cam element and guide elements provided on the cylinder head penetrate each other, the width of which guide elements maximally corresponds to the width of the groove, so that the guide of the holder and of the valve stem can also approach close to the carrier shaft.
In a first preferred embodiment, the holder provided with the sliding surfaces comprises a bearing sleeve in the enclosing element and a hinge pin connected to the valve stem, which hinge pin is rotatably mounted in the bearing sleeve. The sliding surfaces can be configured on the hinge pin.
For the connection between the hinge pin and the end of the valve stem, the hinge pin can be assigned a connecting part, which is connected to the valve stem and is provided with the sliding surfaces. The hinge pin and the connecting part can be arranged in L-shape or in T-shape, the valve stem, for example, being screwed, or the like, into the connecting part protruding from the hinge pin. The T-shape of the holder is especially usable in those embodiments in which the cam element has a groove.
The connecting part can also be of fork-shaped configuration or can be assembled from two L-shaped parts connected to the hinge pin. In this embodiment, a transverse part or two transverse members additionally connected to the valve stem extend parallel to the hinge pin in order to increase the strength of the connection.
In a further embodiment it is envisaged that the valve stem is offset in relation to the cam element in the axial direction of the shaft. The axially projecting region of the holder can then be fastened to the upper part of the valve stem and can have for this purpose a bore, the axis of which lies in the axis of the valve stem. The upper end of the valve stem can be provided with a threaded bore, in which a fastening screw passing through the bore of the holder engages. In order to make the fastening screw accessible, in this embodiment the driven shaft of the valve drive running thereabove is preferably provided with a bore through which a helical spring or the like can be brought up to the fastening screw of the valve stem. Insofar as the carrier shaft is hollow and is used for the supply of oil to that peripheral surface of the cam element which is covered by the enclosing element, a core barrel is drawn through the driven shaft following the fastening and adjustment of all valve stems, which core barrel covers from inside the access bores for the fastening screws.
In a further preferred embodiment, the bore, in the axially projecting region of the holder provided with the sliding surfaces, is a threaded bore, and the upper end of the valve stem has a thread which is screwed into the holder. Here, too, the valve stem can be adjusted and fixed through a corresponding bore of the carrier shaft, for example using a counter screw inserted from above. In place of the screw connection, other connection options are also conceivable, for example pressing, squeezing, clamping, connection by means of a transverse pin, etc.
An especially simple, holderless embodiment provides for a direct mounting of the valve stem in the enclosing element, in that an upper end is formed in a cranked or T-shape and is inserted in at least one bearing sleeve, connected to the enclosing element, or insertion opening configured there. The sliding surfaces can be provided in the upper part of the valve stem, which can also there be thickened, for example.
If the sliding surfaces are configured at the upper end of the valve stem, yet other options are obtained in terms of design particulars. Thus, at the upper end of the valve stem, a bearing eye can be configured, the outer contour of which is provided with the sliding surfaces and in which the hinge pin of the holder engages, which hinge pin, in this embodiment, can be fixedly connected to the enclosing element.
For the mounting of this valve drive in the cylinder head, the lower end of the valve stem is preferably provided with a thread and screwed into the valve disk. The valve drive can therefore be inserted into the cylinder head from above, the valve preferably being set to maximum opening, whereupon the valve disk is fixed. The parts of the valve can therefore also consist of different materials, for example of ceramic, steel, etc. The thread can here also have the function of an expansion bolt. Depending on the arrangement and configuration of the inlet or outlet duct, it is also herein conceivable for the valve disk to extend obliquely to the valve stem. If the camshaft is built out of individual elements, the cylinder head can also be configured in one piece and have bush-type bearing openings.
Despite the forced guidance through the enclosing element, the valve, too, can assume a slant and, in at least one principal direction, deviate from the right angle to the rotation axis of the shaft if the valve stem is arranged such that it is displaceable, relative to the cam element, parallel to the shaft. This is possible if the hinge pin can slide either in the bearing sleeve of the enclosing element or in the bearing eye of the valve stem. The displacement travel depends on the slant of the valve stem and generally amounts to just a few millimeters.
In a further preferred embodiment, two valves can be actuated jointly. For this purpose, it is envisaged, for example, that the cam element is provided on both sides with a holder for a valve guided at the upper end next to the cam element. In a second embodiment, the two valves can be disposed between two equidirectional cam elements, the two holders having a common hinge pin disposed in both enclosing elements.
An arrangement in which the axis of the valve stem of the parallel-running axial plane of the shaft is laterally offset is also possible as a result of the guide of the valve stem, which guide is drawn right up into the holding region, in which embodiment altered opening and closing characteristics of the valve are obtained.
The lateral arrangement of the valve stems next to the cam elements and their guide, drawn up practically as far as the carrier shaft, can give rise, as already mentioned, to especially low cylinder heads, this lateral arrangement likewise promoting the guidance of the inlet and outlet ducts. The duct can in fact be guided next to the relatively large bearing recess, necessary in the cylinder head, for the cam element, in which case, in combination with a corresponding slant, cross-sectional configuration and valve seat configuration, for example appropriate to the oblique valve disk, the cylinder head height can be so far reduced that, even though its basic measure is dependent, in turn, on the minimum guide length of the valve stem, this guide length lies substantially closer to the driven shaft and is preferably also divided into two mutually spaced portions. Especially in the embodiment in which the two valves are provided on a common hinge pin between two cam elements, the valves can be distanced sufficiently far away from the cam elements that a problem-free arrangement of the ducts is possible. The hinge pin can in this case also be cranked in the style of a stirrup, so that its middle portion runs closer to the shaft.
A first preferred embodiment of a cylinder head has a semicircular bearing recess for the shaft and a semicircular bearing recess for each cam element, in the region of a bore for the reception of the valve stem guide surfaces being provided for that end of the valve stem which is connected to the enclosing element, which guide surfaces extend in the direction of displacement of the valve. In particular, a guide sleeve made from an appropriate bearing material and whose upper end has a slot is pressed into each bore of the cylinder head, the guide surfaces being provided in the region of the slot. The slot serves the passage of the hinge pin to the connecting point with the enclosing element, which connecting point lies alongside the guide sleeve. The guide surfaces can also be provided on rollers, rolling elements or the like.
In a second, particularly material-saving embodiment of the cylinder head, it is envisaged that it has a base element having a bearing web for the shaft and having a guide web for the valve, which guide web is disposed in the region of the bore for the reception of the valve stem, the guide web being assigned guide surfaces for that end of the valve stem which is connected to the enclosing element. If the cam element has a groove, the guide web can be configured in two parts in extension of the groove and the thickness of the two parts of the guide web corresponds maximally to the width of the groove.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail below with reference to the figures of the appended drawings, without being restricted thereto.
FIGS. 1 to 3 show a first embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 1 showing a section perpendicular to the driven shaft, FIG. 2 a longitudinal section and FIG. 3 the detail A from FIG. 2 in enlarged representation;
FIGS. 4 to 7 show a second embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 4 showing an exploded representation in oblique view, FIG. 5 a longitudinal section, FIG. 6 the detail A of FIG. 5 in enlarged representation and FIG. 7 an enlarged section along the line VII—VII of FIG. 5 ;
FIGS. 8 to 10 show a third embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 8 showing an exploded representation in oblique view, FIG. 9 a longitudinal section and FIG. 10 the detail A of FIG. 9 in enlarged representation;
FIGS. 11 to 13 show a fourth embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 11 showing a top view of the empty cylinder block, FIG. 12 a longitudinal section and FIG. 13 the detail A of FIG. 12 in enlarged representation;
FIGS. 14 to 16 show a fifth embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 14 showing a longitudinal section, FIG. 15 a section perpendicular to the shaft and FIG. 16 a cut oblique view;
FIGS. 17 to 20 show details of a sixth embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 17 showing an oblique view of a holder, FIG. 18 a section through the holding region, FIG. 19 an oblique view of the guided holding region and FIG. 20 a side view of the guided side region;
FIGS. 21 to 24 show a seventh embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 21 showing an oblique view, FIG. 22 a holder in oblique view, FIG. 23 a section through the holding region and FIG. 24 a section through the holding region along the line XXIV of FIG. 23 ;
FIGS. 25 to 30 show an eighth embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 25 showing an exploded representation in oblique view, FIG. 26 a carrier shaft portion having a cam element, FIG. 27 a longitudinal section in oblique view, FIG. 28 the longitudinal section in top view and FIGS. 29 and 30 details of the holding region of a valve in oblique view and in section;
FIG. 31 shows a variant of the holder with a hinge pin;
FIGS. 32 to 40 show a ninth embodiment of a cylinder head having a valve drive comprising at least one valve in three different positions during a revolution of the carrier shaft, FIG. 32 showing a longitudinal section and FIG. 33 a cross section through the cylinder head and FIG. 34 an oblique view of the holding region, respectively in the valve-closing setting. FIG. 35 represents a cross section and FIG. 36 a front view of the holding region, respectively in a part-opened valve setting. Further, FIG. 37 shows a cross section, FIG. 38 a longitudinal section and FIG. 39 an oblique view through the cylinder head, and FIG. 40 a section through the holding region, respectively in valve-open setting;
FIGS. 41 to 47 show a tenth embodiment of a cylinder head having a valve drive comprising at least one valve, FIG. 41 showing an oblique view, FIG. 42 a longitudinal section, FIG. 43 the holding region in front view, FIG. 44 the holding region in section, FIG. 45 a carrier shaft portion in oblique view, FIG. 46 a section along the line XLVI of FIG. 42 and FIG. 47 an oblique view of a detail of the guide;
FIG. 48 shows an oblique view of a guide sleeve and
FIG. 49 shows a cross section through an eleventh embodiment of a cylinder head having a valve drive comprising at least one valve.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A valve drive comprises, in all embodiments, a driven carrier shaft 1 , on which at least one cam element 2 is fixed in a manner which is not described in greater detail. The cam element 2 is surrounded by an enclosing element 4 , which consists especially of high-tensile, low-friction fibers, such as Kevlar, aramid, glass or carbon fibers, which, for example, are made up into a fabric produced in a textile circular-working method or, through helical winding, are made up into a closed loop, of a high-tensile plastics or metal band, or the like. The enclosing element 4 has a holding region 6 having a insertion opening 7 , in which holding region it is hinge-connected to a valve 10 by a holder 12 . As a result, the enclosing element 4 cannot rotate jointly with the cam element 2 , but can translate the latter's rotary motion into an oscillating motion which imparts an opening and closing motion to the valve 10 disposed in a slideway. The valve disk 69 thereby lifts off from the valve seat 70 , or closes it, so that the inlet or outlet duct 89 in the cylinder head 20 , 80 is opened or reclosed. The cam element 2 can have a radial bore 3 , via which, from the hollow shaft 1 , oil can be introduced into the region between the cam element 2 and the enclosing element 4 .
The enclosing element 4 is connected to the valve stem 11 of the valve in several different ways, which are described in greater detail below. The valve stem 11 is guided in the cylinder head 20 , 80 through a bore 88 , in which is inserted a guide sleeve 81 , the lower region of which is closed and the upper end region of which is provided with a slot 82 . In the embodiments according to FIGS. 1 to 16 , the cylinder head 80 has a semicircular bearing recess 91 for the shaft 1 and a semicircular bearing recess 86 for each cam element 2 , which latter bearing recess is provided with a central indentation 92 to create room for the connection between the enclosing element 4 and the holder 12 . The bore 88 emerges upward into the bearing recess 91 for the shaft 1 and opens laterally into the bearing recess 86 for the cam element 2 . The inner sides of the slotted region of the inserted guide sleeve 81 form guide surfaces 85 for the holder 12 of the valve stem 11 or its upper end, which guide surfaces ascend almost up to the shaft 1 . The high-drawn guide allows the height of the cylinder head 80 to be considerably reduced without having to dispense with the necessary characteristics (good heat dissipation, high power take-up, etc.).
In the embodiments according to FIGS. 17 to 49 , the cylinder head 80 is reduced in weight and comprises a base plate 20 , from which at least one bearing web 21 rises up, in which the shaft 1 is mounted. At least one guide web 22 rises up, laterally offset, in the region of the bore 88 for each valve 10 , on which guide web the guide surfaces 85 are directly configured or in which guide web a guide sleeve 81 having the guide surfaces 85 and the slot 82 is inserted. The bearing web 21 and the guide web 22 can be screw-connected, plug-connected or otherwise connected to the cylinder head 20 , 80 ; they can also, however, be configured in one piece with the cylinder head 20 , 80 .
In the embodiments according to FIGS. 1 to 24 , the holder 12 projects laterally over the cam element 2 , and the valve 10 and high-drawn guide lie respectively alongside the cam element 2 .
In the embodiments according to FIGS. 25 to 49 , the usual arrangement, on the other hand, is maintained, i.e. the holder 12 does not lie offset within the envelope of the rotary cam element. In these embodiments, the cam element 2 has a central peripheral groove 31 , which is provided in extension of the guide web 22 . In the axial direction of the shaft 1 , the guide web 22 is no wider than the peripheral groove 31 , so that, when the cam element 2 rotates, the guide web 22 can penetrate into the cam element 2 . The enclosing element 4 has in the holding region 6 a slot 5 , which leaves the groove 31 uncovered and extends approximately over half of the periphery of the enclosing element 4 .
In the embodiment according to FIGS. 1 to 3 , the insertion opening 7 of the enclosing element 4 is provided with a bearing sleeve 68 , in which, from both sides, a hinge pin 14 of a holder 12 is rotatably inserted. That region 61 of the holder 12 which projects axially over the cam element 2 is provided with a bore 62 . The upper end of the valve stem 11 has a threaded bore, in which is inserted a fastening screw 63 which passes through the bore 62 and fixes the valve 10 on the holder 12 . In order to facilitate access to the screw 63 , the above-lying shaft 1 contains a bore 30 through which a tool can access the screw 63 . The hinge pin 14 in this case passes through the slot 82 of the guide sleeve 81 , the outer face of the region 61 bearing the bore 62 and that portion of the hinge pin 14 which is guided in the slot 82 forming sliding surfaces 65 of the holder 12 , which slide up and down on the guide surfaces 85 of the guide sleeve 81 .
In the very similar embodiment according to FIGS. 4 to 7 , the holder 12 is provided, in turn, with a hinge pin 14 , which is rotatably mounted in a bearing sleeve 68 and the axially projecting region 61 of which has a threaded bore and sliding surfaces 65 . The projecting region 61 is mounted displaceably in the guide sleeve 81 , the hinge pin 14 being guided outward through the slot 82 . The upper end of the valve stem 11 is provided with a thread and screwed into the bore 62 of the holder 12 . Here, too, an adjustment of the valve stem and the placement of a fixing counter-screw, via a bore 30 , in the above-running shaft 1 is possible. FIGS. 4 and 5 also show a core barrel 38 (not shown in the embodiment according to FIGS. 1 to 3 ), which, following mounting of the valve drive, is pushed into the shaft 1 and covers the bore 30 from inside. From the enlarged representations of FIGS. 6 and 7 , the guide for the valve stem 11 , which guide approaches close to the shaft 1 , can be especially well seen. The guide is divided into two mutually distanced regions, between which there is disposed a seal 83 for the valve seat 11 .
In the embodiment according to FIGS. 8 to 10 , the valves 10 are arranged at an inclination relative to the right angle to the rotation axis 8 of the shaft. The bearing sleeve 68 of the enclosing element 4 is passed through by a hinge pin 14 , which has regions 61 which project axially on both sides and engage in a respective bearing eye 78 , which bearing eyes are configured at the upper ends of two valve stems 11 and are provided with the sliding surfaces 65 . The bearing eyes 78 allow the slanting of the valve stems 11 , which, upon the lifting motion, move slightly to and fro on the hinge pin 14 . The valve stems 11 are provided on the lower ends with a threaded portion, which is screwed into the corresponding threaded bore of the valve disk 69 . The hinge pin 14 is again guided in the slots 82 of the two guide sleeves 81 .
In the embodiment according to FIGS. 11 to 13 , the two valves 10 are disposed on a hinge pin 14 connecting two equidirectional cam elements 2 and are inserted in a respective bearing sleeve 68 of an enclosing element 4 . The two valve stems 11 are slightly inclined, so that the ducts 89 can be guided in the region between the cam elements 2 , as is clearly evident from the top view of FIG. 11 . The two bearing recesses 86 for the cam elements 2 , inclusive of their central indentations 92 for the connecting regions, containing the bearing sleeves 68 , between the enclosing elements 4 and the hinge pin 14 are connected by a central slot 87 , in which the up-and-down moving hinge pin 14 is guided. The middle region of the latter can further be cranked in the style of a stirrup, so that it is proximate to the shaft 1 , whereby the middle region of the slot 87 can be less deep. Emerging into the slot 87 are the two oblique bores 88 , in which are inserted the guide sleeves 81 which, in the upper regions, are slotted for the passage of the hinge pin 14 . The bearing eyes 78 have the sliding surfaces 65 , which slide on the inner guide surfaces 85 of the guide sleeves 81 . As a result of the oblique inclination of the valve stems 11 , the bearing eyes 78 move slightly left and right.
FIGS. 14 to 16 show a similar embodiment, in which the height of the cylinder head 80 , despite sufficient guide length for the valves 10 , is once again reduced, since, in the ducts 89 , diagonal valve seats 70 for the valve disks 69 are configured, which, for their part, are again fastened obliquely to the valve stems 11 , for example by the thread 77 , but which could equally be replaced by a press-fastening or another kind of fastening. In the oblique view of FIG. 16 , the bearing shells 93 for the shaft 1 are also visible, which are mounted on the top side of the cylinder head 80 .
In FIGS. 17 to 24 , two embodiments are shown, in which only the guide, but not the valve 10 , is laterally offset in relation to the cam element 2 . According to FIGS. 17 to 20 , the holder 21 has a hinge pin 14 which is inserted in the insertion opening 7 of the enclosing element 4 and projects on both sides. In its projecting regions 61 , a fork-shaped connecting part 18 , provided with two eyes, is pivoted, on which the end of the valve stem 11 is centrally fixed. The connecting part 18 has a blind bore 25 , the floor of which is a spherical surface and into which a receiving bore 26 for the upper end of the valve stem 11 emerges, which end, in this embodiment, has an offset spherical head. Inserted in the blind bore 25 is a screw 27 , the front side of which likewise has a spherical surface and fixes the spherical head of the valve stem 11 . If the screw 27 has an end stop, then the spherical head is held not clamped but rotatably. The lateral members 19 of the fork-shaped connecting part 18 , which members are provided with the eyes 78 , are provided on the outer side with the sliding surfaces 65 , which are guided on the guide surfaces 85 . As can be seen from FIG. 19 , the guide surfaces 85 are configured on guide webs 22 or inserts made from bearing material, which on both sides of the cam element 2 approach close to the shaft 1 .
According to FIGS. 21 to 24 , the guide webs 22 form cylindrical elements and the connecting part 18 of the holder 12 has a circular outer contour. The lateral members 19 of the connecting part 18 , which members are provided with the eyes 78 , constitute cylinder segments, which on the outer side have sliding surfaces 65 and are connected by a transverse part 28 and the distance apart of which corresponds to the width of the cam element 2 . The connecting part 18 has in its lateral members 19 the two eyes 78 , which are mounted rotatably on the hinge pin 14 projecting from the insertion opening 7 of the enclosing element 4 on both sides ( FIG. 23 ). Self-evidently, the hinge pin 14 can also be mounted rotatably in the insertion opening 7 , or a bearing sleeve 68 provided there, and can be fixed in the eyes 78 . In the transverse part 28 of the holder 18 , the blind bores 25 and the bottom-side receiving opening 26 are provided, through which the upper end of the valve stem 11 , provided with an offset spherical head, is inserted. A screw 27 inserted in the blind bore 25 holds the valve stem 11 . The cylindrical guide web 22 has a slot 82 in the width of the cam element 2 , so that the cam region has the necessary passage clearance. The holder 12 connected to the enclosing element 4 is thus guided up and down in the cylindrical guide web 22 in a piston-like manner.
FIGS. 25 to 30 show a first embodiment having a cam element 2 provided with a central groove 31 and having an enclosing element 4 provided in the holding region 6 with a central slot 5 . The holder 12 used in this embodiment has a hinge pin 14 inserted in the insertion opening 7 of the enclosing element 4 , said insertion opening being provided, where appropriate, with a bearing sleeve 68 , which hinge pin is provided with a front-sided blind bore 25 and a therein emerging receiving bore 26 for the upper end of the valve stem 11 . The upper end of the valve stem 11 is provided with at least one peripheral channel, in which a rib in the floor of the blind bore 25 and a rib of a fitting piece 16 engage, which fitting piece is held in the blind bore 25 by a screw 17 ( FIG. 30 ). The hinge pin 14 has a flattening on both sides of the receiving bore 26 and the two flattenings form mutually parallel sliding surfaces 65 ( FIG. 25 ). On both sides of the valve stem 11 , which is mounted displaceably in the bore 88 of the cylinder head or of the cylinder head base plate 20 , a guide web 22 rising up in the bearing recess 86 of the cylinder head 80 or from the base plate 20 , extends respectively close to the carrier shaft 1 of the cam element 2 , the mutually facing surfaces of the guide webs 22 forming the cylinder-head-fixed guide surfaces 85 , on which the sliding surfaces 65 of the hinge pin 14 are guided in sliding motion. The upper regions of the guide webs 22 , when the cam element 2 rotates, enter through the slot 5 into the groove 31 , which extends at least over the cam region of the cam element 2 .
FIG. 31 shows a variant in which the holder 12 , similar to the embodiment according to FIGS. 17 to 20 , comprises a hinge pin 14 , in which the upper end of the valve stem 11 , which end has a spherical head, is held directly by a screw 27 . The screw 27 preferably does not clamp the spherical head, but holds it swivel-mounted. The sliding surfaces 65 are formed, in turn, by flattenings of the hinge pin 14 .
FIGS. 32 to 40 show a further embodiment having grooved cam elements 2 , the enclosing elements 4 of which, in turn, have slots 5 in the holding regions 6 . This embodiment differs from the previous embodiment by the configuration of a reinforced holder 12 . This comprises a connecting part 18 formed from two L-shaped elements, each of which has a side part 19 , having an eye 78 , and a transverse member 29 , having a bore 34 . The two L-shaped elements are fixed on the projecting ends of the hinge pin 14 . The upper end of the valve stem 11 is provided with two or more mutually parallel bores, the hinge pin 14 being put through the upper bore and the cotter pin 33 being put through the lower bore. This connection is primarily suitable for very thin valve stems 11 , which, where appropriate, might be too much weakened by a single bore for the hinge pin 14 , or the hinge pin 14 of which has too small a cross section. In this embodiment, three different settings of the valve 10 are shown, which are also similar in the other embodiments. FIGS. 32 to 34 show a basic setting with two valves 10 , which close the inlet and outlet ducts 89 . The guide webs 22 rising vertically from the cylinder head base plate 20 , as can be seen, above all, from FIG. 33 , approach close to the carrier shaft 1 of the cam elements 2 . The bore for each valve stem 11 is configured within a guide sleeve 81 ( FIG. 48 ), which, in the region inserted in the cylinder head base plate 20 , is closed and in the region situated in the guide web 22 has the slot 82 , which is passed through by the jutting transverse elements of the holder 12 . The width of those wall parts of the guide sleeve 81 which remain on both sides of the slot 82 and on which the guide surfaces 85 , rising up almost to the carrier shaft 1 , are provided corresponds to the thickness of the guide web 22 and the width of the groove 31 , which, in its extension, is configured all the way round in the cam element 2 .
As is clearly discernible in the comparison with the oblique view according to FIG. 34 , in the section according to FIG. 32 the remaining wall parts of the guide sleeve 81 and the guide web 22 are thus situated exactly behind the valve stem 11 and hence are not, however, fully visible there in the section perpendicular thereto according to FIG. 33 .
FIGS. 35 and 36 are details of the 120°-twisted setting of the cam element 2 , in which cam element the valve disk 69 has been lifted from the valve seat 70 . The holder 12 is displaced downward in the guide sleeve 81 and the guide web 22 has entered the groove 31 through the slot 5 present in the holding region 6 of the enclosing element 4 , i.e. the two cam regions of the cam element 2 move past on both sides of the guide web. FIG. 36 also shows the twisting of the holder 12 relative to the enclosing element 4 about the axis 15 of the hinge pin 14 , since the valve stem 11 does not extend perpendicular to the tangent to the cam element 2 , as is the case in the basic setting according to FIG. 33 and in the open setting according to FIG. 37 . In the open setting, the holder 12 is pushed downward in the guide sleeve 81 over the full height of the slot 82 and bears almost against the surface of the cylinder head base plate 20 . In FIG. 40 , the wall part of the guide sleeve 81 with the guide surface 85 is therefore visible in the groove 31 of the cam element 2 .
In this embodiment, the sliding surfaces 65 are provided on the valve stem 11 , the free ends of the transverse members 29 also, where appropriate, being able to be flattened and guided along the margins of the slot 82 of the guide sleeve 81 .
In the embodiment according to FIGS. 41 to 47 , a further variant having grooved cam elements 2 is shown, the holder 12 having a T-shape ( FIGS. 44 , 47 ), the transverse part of which forms the hinge pin 14 and the central longitudinal part of which either forms the connecting part 18 to the valve stem 11 or the valve stem 11 itself. In the former case, the connecting part 18 is suitably connected to the valve stem 11 , for example by a screw connection, if one of the two elements has a thread and the other a threaded bore (similar to FIG. 7 ). In the second case, the valve stem 11 , as in the embodiment according to FIGS. 8 to 16 , is provided at the lower end with a thread 77 and screwed into the valve disk 69 , which, on the bottom side, can have tool engagement elements 72 , for example. As FIG. 44 shows, the two side portions of the hinge pin 14 are inserted in the insertion opening 7 which is divided by the slot 5 in the enclosing element 4 ( FIG. 25 ) and in which, where appropriate, bearing eyes 68 are disposed. The slot 5 is sufficiently large for the two parts of the insertion opening 7 in the enclosing element 4 made of flexible material to be moved so far apart that the hinge pin 14 can be inserted from the slot 5 bilaterally into the insertion opening 7 . The further design construction of this embodiment largely corresponds to that of the embodiment according to FIGS. 31 to 40 . The sliding surfaces 65 are configured on the valve stem 11 or the connecting part 18 , which is guided in the slotted guide sleeve 81 along the guide surfaces 85 . The diameter of the hinge pin 14 is less than the diameter of the valve stem 11 or of the connecting part 18 , as is evident from the section through the hinge pin 14 shown in FIG. 46 . The slot 15 in the enclosing element 4 must exceed in height at least the lift of the valve. Alternatively, it is also possible to extend the slot over the whole of the periphery of the cam element 2 , so that the enclosing element 4 is divided into two narrow loops, which are connected by the hinge pin 14 only in the holding region 6 . For the axial securement of the enclosing element 4 , it is advantageous if the cam element 2 has at the periphery an indentation, laterally delimited by the marginal webs 9 , the height of which indentation maximally corresponds to the thickness of the enclosing element 4 . In the case of a division into two loops, the margins which delimit the groove 31 are preferably provided with marginal webs 9 . In this embodiment, the groove 31 is provided only over the cam region, but, as in the embodiment according to FIGS. 32 to 40 , can equally be configured all the way round on the cam element 2 .
A further variant is shown in FIG. 49 . In this embodiment, the axis 71 of the valve stem 11 does not intersect the axis 8 of the carrier shaft 1 , but runs past at a distance therefrom. The valve drive is thus asymmetrical, so that changes in the opening and closing time, as well as in the length of opening, can be obtained by displacement of the rolling and contact lines. The other construction of this embodiment corresponds to that of the embodiments already described above. The guide web 22 engages in the circumferential groove 31 of the cam element 2 and the valve stem 11 is guided through the guide sleeve 81 into the holding region 6 of the enclosing element 4 . The connection of the valve stem 11 and the enclosing element 4 is indicated by the cut hinge pin 14 . An asymmetrical arrangement and guidance of the valve is possible in all the embodiments previously described. In addition, it also allows a steeper arrangement of the inlet and outlet ducts 89 , if the lateral offsetting of the carrier shaft is effected in the direction shown in FIG. 49 , i.e. toward the side facing away from the ducts 89 .
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The invention relates to a valve drive, in particular for internal combustion engines of motor vehicles, comprising at least one cam element ( 2 ) that is located on a driven shaft ( 1 ) and at least one lifting valve ( 10 ), which has a valve stem ( 11 ) and can be displaced by the cam element ( 2 ). The cam element ( 2 ) is pivotally mounted inside a flexible encapsulation element ( 4 ), which is connected to one end of the valve stem ( 11 ). The end of the valve stem ( 11 ) is guided in the displacement direction of the valve ( 10 ).
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The invention relates to the field of protective case accessory for cellular Smartphone devices and Software Applications running on such devices. More specifically, the invention comprises a Multi-Function button integrated into a cellular smartphone protective case accessory, using a Bluetooth transceiver also embedded in the smartphone protective case accessory that is configured to attach to a smartphone device, facilitating the initiation or activation of features or software applications running on the Smartphone device, or both and also serves as a protective case for the smartphone device.
[0006] 2. Description of Related Art
[0007] There are many known protective case devices for protecting hand-held smartphone devices. Most of these are made from plastic or rubber or a combination of both and have no interaction with the cellular phone device and serve only to protect such device and sometimes adding aesthetic value to the user. However, there are some protective cases that do interact with the cellular phone device. Some offer back up power to extend the cellular phone talk time or some may include an integrated card reader that facilitate scanning of a credit card and communicating the card information to the cellular phone that uses a software application to process the credit card information. These devices may use electrical connections such as conductive metal contacts or wireless connections such as Bluetooth, to interface to the cellular phone device.
[0008] Portable smart phone devices facilitate the use of a plethora of applications available for download from any available APP store that allow the device to be used for multiple applications such as gaming, social networking, navigation and many more. There are available accessories that connects wirelessly to the Smartphone or plug into the accessory jack on the Smartphone, that when combined with a software application running on the Smartphone, serves as a multifunction button allowing the user to activate features and applications on the phone by using a series of pre-programmed presses of the multifunction button to activate each feature or software application. One such type of application is programming a short press of the multifunction button to activate the camera feature in the Smartphone to take a picture. Another application is programming a long press of the multifunction button to toggle the mute function or flashlight application on the Smartphone. There can also be a series of long and short presses of the multifunction button programmed to activate any of the embedded features or downloaded software applications on the Smartphone. By using a dedicated button to activate select features or application on the Smartphone it allows the user to quickly access and activate the feature without having to turn on the display, unlock the phone, select the feature or application and activate it.
[0009] Available multifunction button accessories for Smartphone's such as those that are inserted into the accessory connector of the Smartphone prevents the use of wired accessories when plugged in and can be misplaced if removed. Alternatively, wireless multifunction buttons although still allowing access to the accessory connector on the Smartphone can also be misplaced or is designed to be mounted in a fixed location (such as in a vehicle) thus limiting the use of the multifunction button.
[0010] Standard smart-phone protective case accessories, although providing variable amount of protection and sometimes interfacing with the portable smart-phone device, do not facilitate the use of a multifunction button, providing easier and quicker access to activate features and software applications on the Smartphone and providing tactical feedback to the user and ease of use when wearing gloves. Therefore, there is room for improvement within the art.
BRIEF SUMMARY OF PRESENT INVENTION
[0011] The present invention integrates a multifunction button into a protective case for a smartphone device, allowing for quicker access to activate embedded features and software applications running on smartphone devices without the need to unlock the phone and access the application, which would require additional time and reduce the battery life (extended operation of display). The multifunction button, when activated, preferably sends data by means of a Bluetooth connection to the smartphone device, prompting the features or software application running on the smartphone device to activate. Having the multifunction button integrated into the Smartphone protective case accessory provides easy access to a physical button allowing the user to operate Smartphone features such as the camera, or software applications, such as Google Maps, quickly even when wearing gloves. The present invention also functions as a protective case for the smartphone device adding value for the user.
[0012] The Bluetooth transceiver is embedded into the protective case and preferably powered by a rechargeable or non-rechargeable type battery and may contain a method of charging rechargeable batteries. The protective case is preferably attached to the smartphone device, preferably by the use of mechanical features similar to those used in a typical protective cases designed for such devices.
[0013] The protective case may also contain a means of providing auxiliary power to the smartphone device, functioning as a battery life extender or charger for the smartphone device. This is preferably implemented with a DC to DC voltage converter that provides a fixed voltage to the smartphone device preferably by electrically conductive metal contacts interfacing with the charging contacts or jack on the smartphone device.
[0014] Although the use of Bluetooth as a means of communicating to the smartphone is proposed in this invention, it should not be limited as such. Other methods such as connecting directly to existing data ports with electrically conductive metal contacts on the smartphone device such as the accessory jack or multifunction connector (also typically used for charging the smartphone device) by means of a electrical connection and sending data to the smartphone to operate the PTT application. Alternately, the Multifunction button could replace the function of any one or more of the existing buttons on the Smartphone such as the Up or Down volume buttons by making that button larger in the protective case and reassigning the function in the accompanying software application. In this case the multifunction button would have mechanical features to allow it to press the existing button on the smartphone to activate the desired feature or application and there would be no need for electrical or wireless connection between the protective case accessory and the smartphone.
[0015] The invention preferably includes an audio amplifier and speaker to increase the audio output of the Smartphone. This invention is not limited for use with smartphone devices and could be used with tablets or any handheld smart devices that is capable of running software applications.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 is a view of the rear profile of the invention, when attached to smartphone device, showing the preferred layout of the multifunction button.
[0017] FIG. 2 is a view of the left side profile of the invention, when attached to the smartphone device.
[0018] FIG. 3 is a view of the bottom profile of the invention, when attached to the smartphone device, showing the accessory port and charging port.
[0019] FIG. 4 is a block diagram of the invention.
[0020] FIG. 5 is a block diagram of the invention, showing power distribution from the embedded battery in the protective case device to the smartphone device.
[0021] FIG. 6 is a view of the rear profile of the device showing a removable Multifunction button (MFB).
REFERENCE NUMERALS IN THE DRAWINGS
[0000]
101 Opening for smartphone camera lens
102 Volume/Scroll buttons
103 Multifunction button (MFB)
104 Protective case accessory
105 Opening to retain removable Multifunction button
301 Charging and data port
302 Accessory port
401 Battery
402 Audio amplifier
403 Bluetooth transceiver
404 Loudspeaker
501 Voltage multiplier
502 Voltage regulator
503 Smartphone device
DETAILED DESCRIPTION OF THE INVENTION
[0036] FIG. 1 shows the rear view of the present invention in an assembled state. The protective case accessory 104 is configured to attach to a cellular smartphone device (not shown), preferably to the rear of the device. Of course, the invention includes features that would allow it to readily and securely attach as shown, though the reader should bear in mind that many other possibilities to securely attach the protective case accessory 104 to the smartphone device exists. Such methods include adhesives, form fitted rubber over-mold, screws, snaps etc. Slots 101 in the protective case accessory 104 allow access to the smartphone camera lens that is used to take pictures or video. Alternately, the slot could be sealed with a clear plastic or glass lens to prevent water and dust from getting to the smartphone device in a ruggedized or water resistant protective case. The multifunction button 103 is preferably placed at the rear of the protective case device 104 to allow for easy access but the reader should bear in mind that there are many other locations where the multifunction button could be placed in the protective case to achieve similar function. One such alternative would be to place the multifunction button 103 on the side of the protective case accessory 104 . Another alternative would be to place the multifunction button on the top of the protective case accessory 104 . The Multifunction button 103 is positioned in the housing of the protective case accessory 104 such that the user has easy access while holding the smartphone device in an assembled state. Electrical elements (not shown) embedded in the housing of the protective case accessory 104 allow initiation of the features and software applications when the multifunction button is pressed. Although not shown in the present embodiment, LED indicator(s) to show power or operating status would be preferred.
[0037] FIG. 2 shows a perspective view of the left side of the present invention in an assembled state. The volume and scroll buttons 102 facilitates the use of the volume and scroll buttons existing on the smartphone device (not shown).
[0038] FIG. 3 is a perspective view of bottom of the present invention, when attached to the smartphone device, showing slots in the protective case accessory for accessing the smartphone device's accessory port 302 and charging port 301 . It is preferred that a multifunction LED is used to show power or operating status. The reader should bear in mind that although a status LED is preferred as described in the embodiment of the invention, there are many other options to provide status indication to the user such as using multiple LED's, LCD displays, vibration, audible tones etc.
[0039] FIG. 4 shows the block diagram of the present invention. The multifunction button 103 when pressed completes an electrical circuit (not shown in embodiment) that signals the Bluetooth transceiver 403 to send a data command to the Smartphone device to activate the desired feature or software application on the Smartphone. Alternatively, whenever the speakerphone feature is enabled or loud audio is selected by software applications running on the Smartphone device, it sends the audio signal over the Bluetooth link to the Bluetooth transceiver 403 embedded in the protective case accessory. The audio signal is then demodulated and amplified by the audio amplifier 402 and transmitted to the speaker 404 in the protective case accessory. This allows for higher audio output when the protective case accessory is attached to the smartphone device.
[0040] FIG. 5 is a block diagram of the preferred power distribution showing the transfer of power from the protective case accessory to the smartphone device 503 . Preferably, the battery 401 in the protective case accessory powers the Bluetooth transceiver 403 and the audio amplifier 402 . Additionally, it is preferred that the battery output is connected to a DC to DC voltage multiplier 501 to increase the voltage from the battery which is then regulated by the voltage regulator 502 preferably to 5.0 Volts. This voltage regulator 502 output is then connected to the smartphone device 503 charging contacts (not shown) and distributed to the charging circuit (not shown) to charge the battery (not shown) in the smartphone device 503 . All the electronic components are connected using electrical conductors.
[0041] FIG. 6 shows the rear view of an alternate application of the present invention with the MFB 103 disassembled from the protective case 104 . The MFB button 103 contains all the electrical components (not shown) necessary to wirelessly connect to the smartphone device. Examples are Bluetooth wireless module, battery to power the Bluetooth module, LED and button all encased in a separate mechanical housing that forms the MFB 103 . The protective case 104 is configured with a opening to retain the MFB 103 while still allowing it to be removed if intended to be used remotely.
[0042] Although the preceding description contains significant detail, it should not be construed as limiting the scope of the invention but rather providing illustrations of the preferred embodiments of the invention.
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A protective case accessory with integrated Multifunction button configured for attachment to a cellular smartphone device, facilitating the initiation of embedded features or software applications, or both, when attached to the Smartphone device. The invention includes a Multifunction button integrated into a protective case accessory and preferably uses a Bluetooth transceiver to connect wirelessly to a smartphone device to send and receive audio or data communication, or both.
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BACKGROUND OF INVENTION
[0001] This invention relates to automotive vehicle warning lights, and more specifically, to an integrated warning light assembly having a parabolic reflecting surface and a snap fit design.
[0002] Automotive vehicle advanced restraint systems incorporate a number of features that supplement standard safety belt systems. One such feature is the system's ability to automatically disable the passenger-side airbag during certain vehicle operating conditions. The operative status of the passenger-side airbag is preferably communicated to the vehicle occupant via an instrument panel warning light.
[0003] Conventional warning light assemblies combine a light source disposed within a housing and a window with warning graphics printed thereon, typically referred to as a graphics plane. The graphics plane is positioned intermediate the light source and the vehicle occupant. Typically, the graphics plane is positioned substantially flush with the instrument panel surface, and the housing and light source are hidden from view. When it is desired to communicate information disposed on the graphics plane to the vehicle occupant, current is passed through the light source thereby illuminating the graphics plane.
[0004] Conventional warning light assemblies have many sub-components, making the assembly process complex and time consuming. Furthermore, typical assemblies do not allow for sub-component interchangeability. For example, if it is desired to add a light intensity controlling resistor package or change the type of light source, the entire assembly has to be replaced, which is cost ineffective. It would be most beneficial and cost effective to have a permanently attached piece and an interchangeable piece that could be substituted if such changes were desired. It is therefore desired to have a vehicle warning light that is easy to assemble, sub-component integrated, and adapted for sub-component interchangeability.
SUMMARY OF INVENTION
[0005] It is an object of the present invention to provide an integrated warning light assembly that overcomes the disadvantages of the prior art.
[0006] The present invention advantageously provides for an automotive vehicle an integrated warning light assembly having a front half with a parabolic reflecting surface and an orifice therethrough, and a rear half with a light source attached thereto and a plurality of electrical contact terminals molded therein, where the front half is adapted to receive the rear half in snap fit fashion and where the light source extends through the orifice.
[0007] According to a feature of the present invention, the rear half may be interchanged with other rear halves without having to replace or change the front half, thereby saving on part cost.
BRIEF DESCRIPTION OF DRAWINGS
[0008] These and other objects, features, and advantages of the present invention will become apparent from a reading of the following detailed description with reference to the accompanying drawings, in which:
[0009] [0009]FIG. 1 is a perspective view of an automotive vehicle integrated warning light assembly according to the present invention;
[0010] [0010]FIG. 2 is a perspective view of an alternative embodiment of the automotive vehicle integrated warning light assembly according to the present invention;
[0011] [0011]FIG. 3 is a top, cut-away view of an integrated warning light assembly according to the present invention;
[0012] [0012]FIG. 4 is an exploded, perspective view of an integrated warning light assembly according to the present invention; and
[0013] [0013]FIG. 5 is a perspective, cut-away view of an alternative embodiment of a rear half of the integrated warning light assembly according to the present invention.
DETAILED DESCRIPTION
[0014] Referring to FIG. 1, an integrated warning light assembly 10 for an automotive vehicle advanced restraint system is illustrated. The warning light assembly 10 is a two piece snap fit design including a front half 12 and a rear half 14 . The warning light assembly 10 is adapted to be attached to a vehicle instrument panel. A pair of wing-like mounting tabs 18 project outwardly and substantially perpendicularly from a pair of opposing sidewalls 16 . Each mounting tab 18 has a hole 19 therethrough that is adapted to receive a conventional fastener, such as a screw, in order to facilitate mounting the integrated warning light assembly 10 to the instrument panel. In an alternative embodiment, as shown in FIG. 2, a pair of steel spring tabs 22 are attached to a pair of opposing sidewalls 16 . Mounting guidewalls 24 , projecting perpendicularly from the sidewalls 16 , are disposed, in parallel, on either side of each spring tab 22 . The spring tabs 22 and corresponding mounting guidewalls 24 cooperate to facilitate mounting the integrated warning light assembly 10 to the instrument panel in snap fit fashion if so desired. The front half 12 is molded with two options for mounting onto the vehicle instrument panel, although other mounting options may be employed without departing from the scope of the present invention.
[0015] As shown in FIG. 1, the front half 12 has four sidewalls 16 that form a substantially box like shape. Each sidewall 16 has a front edge 17 and a rear edge 20 . Projecting inwardly from the sidewalls 16 and rearwardly from the front edges 17 is a parabolic reflector 25 , as shown in FIG. 3. The parabolic reflector 25 has a predetermined focal point and an orifice 26 adapted to receive a light source 27 therethrough. The light source 27 may be a conventional incandescent light, a light emitting diode or LED, or the like and is positioned at the focal point of the reflector 25 . A translucent graphics plane 23 is disposed on the front edges 17 of the front half 12 . The window 23 has graphics disposed thereon that are visible to the vehicle occupant when the light source 27 is illuminated. The graphics for the advanced restraint system may relate to whether the passenger-side airbag has been disabled, or any other desired information without departing from the scope of the present invention. Projecting from a pair of opposing rear edges 20 in coplanar fashion are a pair of mounting flanges 28 , each having a notch 30 for attaching the front to the rear half, 12 and 14 respectively, as shown in FIG. 4. The front half 12 is a polymeric, preferably polycarbonate, injection molded unit having a reflective finish added to the reflector 25 after the molding process.
[0016] As shown in FIG. 4, the box-like rear half 14 carries the light source 27 and has an electronics package 32 integrated therein. A light socket 34 receives the light source 27 , and a pair of integrated terminals 40 service the electronics package 32 . As shown in FIG. 5, an alternative embodiment of the rear half 14 has three integrated terminals 42 . The third terminal may be used to service a resistor electronics package for controlling light intensity during various exterior ambient light conditions, for example. The rear half 14 further has parallel assembly guidewalls 36 with a ramp 38 therebetween, projecting from opposite sides thereof. The assembly guidewalls 36 and ramps 38 facilitate snap fitting the rear half 14 to the front half 12 . More specifically, the rear half 14 is snapped into the front half 12 by aligning each pair of assembly guidewalls 36 of the rear half 14 with a corresponding mounting flange 28 of the front half 12 . The assembly guidewalls 36 insure that the notches 30 of the mounting flanges 28 are properly aligned with the ramps 38 . The rear half 14 is slid along the mounting flanges 28 via the assembly guidewalls 36 , until the mounting flanges 28 engage the ramps 38 . Continuing to slide the rear half 14 in such a manner will cause the flanges 28 to flex outwardly until the ramps 38 snap into the notches 30 and the flanges 28 are thereby returned to their pre-flexed position. The rear half 14 is a polymeric, preferably polycarbonate, injection molded structure with integrated terminals 40 molded therein.
[0017] The snap fit design not only allows for ease of assembly of the warning light 10 , but also for feature interchangeability without having to replace the entire warning light assembly 10 . For example, the type of light source or the number of electric terminals may be altered by simply interchanging a rear half 14 with the desired feature into the existing front half 12 . This sort of part interchangeability advantageously saves on part cost as the front half 12 is universal regardless of the type of rear half 14 . An additional connector (not shown) snaps into the rear half 14 and powers the unit when in the vehicle.
[0018] While only certain embodiments of the warning light of the present invention have been described, others may be possible without departing from the scope of the following claims.
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An integrated warning light assembly for an automotive vehicle includes a front half having a parabolic reflecting surface with an orifice therethrough, and a rear half having a light source attached thereto and a plurality of electrical contact terminals molded therein, where the front half is adapted to interchangeably receive the rear half in snap fit fashion and where the light source extends through the orifice.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/229,154, filed on Jul. 28, 2009, and herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates in general to forming an adjustable foundation, and in particular, to a concrete slab foundation capable of being raised above the ground.
BACKGROUND OF THE INVENTION
[0003] Many structures have been built on foundations or slabs made of concrete poured on top of soil. Constant changes in the weather and moisture levels in the soil frequently cause damage to such a foundation. In many instances, the foundation may buckle or even crack. This phenomenon occurs for a variety of reasons, including uneven changes in the water content of supporting soils, uneven compacting of soils, and uneven loads being placed on soils. Over time, uneven movement in the soils under a foundation can cause a foundation to bend or crack.
[0004] Therefore, it would be desirable to provide a method and apparatus that would allow a foundation to be poured on top of soil and subsequently raised to a desired height to eliminate potential problems caused by soil movement and/or problematic soils.
SUMMARY OF THE INVENTION
[0005] An embodiment of the system for forming a movable slab foundation as comprised by the present invention has a slab foundation. At least one substantially vertical support member has a hollow body with first and second ends. The first end of the substantially vertical support member is in abutting contact with at least one support surface. At least one support sleeve surrounds the at least one support member. The at least one support sleeve is encased within the slab foundation and is capable of movement axially along the axis of the at least one support member. The at least one support sleeve has an opening through which the at least one support member extends. The opening is substantially geometrically complimentary to the at least one support member. The at least one vertical support member is capable of rotation relative to the at least one support sleeve to restrict the movement of the at least one support sleeve downward relative to the at least one vertical support member, thereby maintaining the height of the at least one support sleeve and the slab foundation relative to the at least one support surface.
[0006] An embodiment of the system for forming a movable slab foundation as comprised by the present invention has a slab foundation. At least one substantially vertical support member has a generally elliptical shaped hollow body with first and second ends. The first end of the at least one support member is in abutting contacting with at least one support surface. At least one support sleeve has a hollow body with inner and outer surfaces. The at least one support sleeve surrounds the at least one support member. The inner surface of the at least one support sleeve has a plurality of tabs extending along and radially inward from the inner surface at select intervals to thereby define a generally elliptical shaped opening. The opening is substantially geometrically complimentary to the at least one support member. The inner surface of the at least one support sleeve also has a plurality of apertures located in and extending therethrough. The outer surface of the at least one support sleeve has at least one reinforcing bar connected to and extending outwardly therefrom. The at least one support member initially extends through the substantially geometrically complimentary opening in the at least one support sleeve. The outer surface of the sleeve body and the at least one reinforcing bar are encased within the slab foundation. The at least one support sleeve and the slab foundation are capable of movement axially along the axis of the at least one support member. The at least one support member is capable of rotation relative to the at least one support sleeve to offset the at least one support member from the opening in the at least one support sleeve to thereby restrict the movement of the at least one support sleeve downward relative to the at least one support member. At least one lifting member is surrounded by the at least one support member. The at least one lifting member has a body with first and second ends, the first end being in abutting contact with the at least one support surface.
[0007] An embodiment of the present invention is directed to a method for forming a movable slab foundation. The method comprises placing a plurality of support surfaces below an intended slab foundation area. A plurality of support sleeves are placed in abutting contact with the plurality of support surfaces. The plurality of support sleeves have a geometrically shaped opening extending axially therethrough. A plurality of support members being geometrically complimentary to the openings are inserted into the openings and are placed within the plurality of support sleeves. The plurality of support members are slid down within the plurality of support sleeves and into abutting contact with the plurality of support surfaces. A slab foundation is formed such that it encases the plurality of support sleeves. The plurality of support sleeves are simultaneously lifted to move the slab foundation along the axes of the plurality of support members to a desired height. The plurality of support members are rotated relative to the plurality of support sleeves, thereby restricting the movement of the plurality of support sleeves downward relative to the plurality of support members and maintaining the desired height of the slab foundation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the features and benefits of the invention, as well as others which will become apparent, may be understood in more detail, a more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings, which form a part of this specification. It is also to be noted, however, that the drawings illustrate only various embodiments of the invention and are therefore not to be considered limiting of the invention's scope as it may include other effective embodiments as well.
[0009] FIG. 1 is a sectional view of a single slab support, illustrating a concrete pier and a support sleeve.
[0010] FIG. 2 is a sectional view of the support sleeve taken along the line 2 - 2 of FIG. 1
[0011] FIG. 3 is a sectional view of the single slab support with a support pipe and a lifting rod inserted and a lifting assembly connected.
[0012] FIG. 4 is a sectional view of the support sleeve and the support pipe taken along the line 4 - 4 of FIG. 3 .
[0013] FIG. 5 is a sectional view of the single slab support with the slab raised a distance above a ground surface.
[0014] FIG. 6 is a sectional view of the single slab support with the slab raised to a final height.
[0015] FIG. 7 is a sectional view of the support sleeve and support pipe taken along the line 7 - 7 of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention now will be described more fully hereinafter with reference to the accompanying drawings in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein; rather, this embodiment is provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0017] Referring to FIG. 1 , a foundation slab 11 may be used to support a house or other building or structure. In this embodiment, the slab 11 is of concrete and initially rests on a ground surface 17 and a support surface or pier 13 . The foundation or slab 11 is typically supported by a plurality of support surfaces or piers 13 , but for simplification purposes, the single pier 13 will be discussed. In this embodiment, the pier 13 is of concrete and has a base plate 15 embedded therein, such that at least the top or upper surface of the base plate 15 is exposed. In this embodiment, the base plate 15 is circular in shape, but in alternate embodiments may comprise different shapes, for example, a rectangle. In this embodiment, the base plate 15 has an anchor bolt 16 connected to it that extends a select distance into the concrete pier 13 . In alternate embodiments, other support members may be connected to the base plate 15 .
[0018] In this embodiment, the hole for the pier 13 is dug with a diameter such that the base plate 15 is fully encased within the concrete. Once the hole is dug as desired, the pier 13 is formed by pouring concrete into the hole. The base plate 15 is then embedded in the concrete of the pier 13 such that the top or upper surface of the base plate 15 is substantially parallel with the ground surface 17 . As previously discussed, in this embodiment, the anchor bolt 16 is connected to the base plate 15 and extends into the concrete of the pier 13 a distance below base the plate 15 .
[0019] In this embodiment, a cylindrical exterior pipe or support sleeve 19 has an outer diameter less than the diameter of the base plate 15 . The support sleeve 19 and the base plate 15 are sized such that the bottom surface of the support sleeve 19 is in supporting contact with the base plate 15 . The length of the support sleeve 19 may be less than or equal to the desired thickness of the concrete slab 11 . In this embodiment, the length of the support sleeve 19 is equal to the thickness of the concrete slab 11 . An inner surface 21 of the sleeve 19 has a plurality of support tabs 23 connected therein that extend along the inner diameter and radially inward a select distance. The support tabs 23 may be connected to the support sleeve 19 through various means, including, but not limited to welding and fasteners. As seen in FIG. 2 , in this embodiment, two support tabs 23 are positioned opposite from one another and extend around the inner surface 21 of the support sleeve 19 at select intervals.
[0020] Referring back to FIG. 1 , reinforcing bars (rebar) 25 are connected to the outer surface of the sleeve 19 . In this embodiment, a first leg 27 of the rebar 25 is connected to and extends outwardly and downwardly at an angle from the sleeve 19 . A second leg 29 of the rebar 25 is substantially perpendicular to the support sleeve 19 and extends between the first leg 27 and the sleeve 19 . The rebar 25 may be welded around the outer peripheries of the sleeve 19 at desired intervals. In an alternate embodiment, various reinforcing members may be connected to and extend outwardly from the outer peripheries of the sleeve 19 in various shapes and configurations.
[0021] A plurality of lift holes or apertures 33 are located in and extend radially outward through the inner surface 21 of the support sleeve 19 . In this embodiment, two lift holes 33 are positioned opposite from one another. The lift holes 33 are designed to accept a lifting device or lifting link.
[0022] The sleeve assembly 19 is positioned atop the base plate 15 . In an alternate embodiment, the lower end of the support sleeve 19 may be lightly tack welded to the base plate 15 . The concrete slab 11 is then poured, thereby embedding the rebar 25 and the sleeve assembly 19 within the slab 11 . The concrete may be kept from bonding to the concrete pier 13 and the base plate 15 by an optional bond breaker layer (not shown).
[0023] Referring to FIG. 3 , after the cement slab 11 has hardened, a support member or support pipe 35 having an elliptical shape ( FIG. 4 ) is inserted into the sleeve 19 and lowered until a lower first end portion makes contact with the base plate 15 . The elliptical shape of the support pipe 35 requires that it be properly oriented with respect to the support sleeve 19 to allow the support pipe 35 to pass by the tabs 23 on the inner surface 21 of the sleeve 19 without interference ( FIG. 4 ). The support pipe 35 is positioned such that the lower first end portion of the support pipe 35 rests on the base plate 15 . The support pipe 35 extends upwardly a selected distance from the base plate 15 . The length of supporting pipe 35 can be varied to accommodate various desired slab 11 heights. As shown in FIG. 4 , the support pipe 35 is elliptical in shape and is adapted to receive a lift bar 37 . The desired final height of the slab 11 is determined by the length of the support pipe 35 .
[0024] Referring back to FIG. 3 , a lifting member or solid lifting rod 37 , with a smaller diameter than the support pipe 35 is inserted into the support pipe 35 and lowered until it makes contact with the base plate 15 . The length of the lifting rod 37 can be calculated such that it may remain within the support pipe 35 once the slab 11 has reached its final desired height. Alternatively, the lifting rod 37 may be removed from the support pipe 35 once the slab 11 has reached its final desired height. After the lifting rod 37 is in place, a lift support plate 38 is positioned on the top of the support rod 43 . The support plate 38 has a plurality of apertures 39 located in and extending therethrough. A lifting device 41 is then mounted on the top of the support plate 38 . In this embodiment, the lifting device 41 is a hydraulic jack mounted on the top of the support plate 38 . A lift plate 43 is then positioned on top of the hydraulic jack 41 . The lift plate 43 has a plurality of apertures 45 located in and extending therethrough. The lift plate 43 is positioned such that the apertures 45 are in alignment with the apertures 39 in the support plate 38 .
[0025] Attachment members or attachment rods 47 are connected to the lift holes 33 in the sleeve 19 in order to lift the slab 11 to its desired height. In this embodiment, the attachment rods 47 contain threads in at least an upper portion thereof. The attachment rods 47 pass through the apertures 39 in the support plate 38 and the apertures 45 in the lift plate 43 . Nuts 48 are threaded onto upper portions of the attachment rods 47 located between the support plate 38 and the lift plate 43 . The nuts 48 may be adjusted once the slab 11 has been lifted to permit removal of the hydraulic jack 41 . Nuts 49 are threaded onto upper portions of the attachment rods 47 , above the lift plate 43 . The nuts 49 prevent the lift plate 43 from moving upward independently from the attachment rods 47 when the hydraulic jack 41 is activated.
[0026] Referring to FIG. 5 , hydraulic fluid pressure is applied to the jack 41 , causing the jack 41 to push the lift plate 43 and the attachment rods 47 upwards relative to the base plate 15 . The jack 41 moves the lift plate 43 and the attachment rods 47 upwards until the foundation slab 11 has been lifted above the ground 17 to the desired height. In the event that the hydraulic jack 41 needs to be removed during the lifting process, the nuts 48 can be tightened against the support plate 38 , thereby allowing the lifting device 41 and the lift plate 43 to be removed if necessary, while maintaining the height of the slab 11 .
[0027] Referring to FIG. 6 , once the slab 11 has reached its desired final height, the tabs 23 on the inner surface 21 of the sleeve 19 will be positioned above the support pipe 35 . In order to secure the slab 11 at the desired height, the support pipe 35 is then rotated such that the support tabs 23 are no longer offset from the elliptical shape of the support pipe 35 ( FIG. 7 ). Once the support tabs 23 are positioned above the support pipe 35 , and the support pipe 35 has been rotated to the proper position, the sleeve 19 , the slab foundation 11 , and the tabs 23 are lowered such that tabs 23 rest upon the support pipe 35 . Once the tabs 23 are securely resting upon the support pipe 35 , the attachment rods 47 , the support plate 38 , the hydraulic jack 41 , the lift plate 43 , and the lifting rod 37 ( FIG. 5 ) are removed.
[0028] Referring to FIG. 6 , the lifting rod 37 ( FIG. 5 ) may be removed if its length is greater than the final height of the slab 11 . Whether the lifting rod 37 is removed or remains within the support pipe 35 , once the slab 11 has reach its desired height, a cap 49 can be inserted into the sleeve 19 . In the event that the height of slab 11 needs to be adjusted, the cap 49 may be removed, the lifting rod 37 reinserted if not already in place, and the support plate 38 , the hydraulic jack 41 , the lift plate 43 , and the attachment rods 47 reconnected. Once the weight of the slab 11 is lifted from the support pipe 35 , the support pipe 35 is rotated such that the tabs 23 on the inner surface 21 of the sleeve 19 will not interfere with the support pipe 35 . The slab 11 is lowered to its original position. The support pipe 35 may be replaced with a supporting pipe with a length to accommodate the new desired height. Once the desired height has been reached, as previously illustrated, the slab 11 may be secured in place by rotating the new support pipe and lowering the weight of the slab 11 and the sleeve 19 onto the new support pipe. As previously discussed, the hydraulic jack 41 , the support plate 38 , the lift plate 43 , the attachment rods 47 , and the lifting rod 37 may then be removed and the cap 49 reinstalled in the sleeve 19 .
[0029] The invention has significant advantages. The invention provides a method and apparatus that allows a foundation to be poured on top of soil and subsequently raised to a desired height to eliminate potential problems caused by soil movement and/or problematic soils.
[0030] In the drawings and specification, there have been disclosed a typical preferred embodiment of the invention, and although specific terms are employed, the terms are used in a descriptive sense only and not for purposes of limitation. The invention has been described in considerable detail with specific reference to these illustrated embodiments. It will be apparent, however, that various modifications and changes can be made within the spirit and scope of the invention as described in the foregoing specification and as set forth in the following claims.
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An embodiment of the system for forming a movable slab foundation as comprised by the present invention has a slab foundation, at least one substantially vertical support member, at least one support surface, and at least one support sleeve. The at least one supports sleeve surrounds the at least one support member and is encased within the slab foundation and is capable of movement axially along the axis of the at least one support member. The at least one vertical support member is capable of rotation relative to the at least one support sleeve to restrict the movement of the at least one support sleeve downward relative to the at least one vertical support member, thereby maintaining the height of the at least one support sleeve and the slab foundation relative to the at least one support surface.
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FIELD OF THE INVENTION
[0001] This invention relates to storage containers, and to 3-dimensional puzzles. It also relates to simulation novelties of the firearm industry.
BACKGROUND
[0002] There are storage containers that are made to hide their valuable contents, particularly by possessing the external appearance of common products that are not related to the contents they enclose. Examples of this are sealable canisters that look like soda cans, or shaving cream dispensers. Those containers are intended to trick would-be thieves or baggage handlers into thinking that the containers are indeed commercial products. The purpose of them is to cause the actual valuables to be overlooked by people to whom they do not belong.
[0003] The problem with those false containers is that they appear to possess little or no perceived value of their own. They could easily be discarded by anyone who does not believe the containers hold much worth to their owner(s).
[0004] There are also other types of concealing containers, one such is a modified book with pages cut out to form a hidden compartment. But, like the shaving cream dispenser or the false soda can, they generally promote the likelihood that their particular contents will be inspected, due to the very nature of the articles themselves.
[0005] By the same token, those false containers may otherwise become recognizable as devices meant to conceal hidden articles, such as currency, keys, jewelry, et cetera. This may be due to the fact that the containers appear slightly different than the trademarked products that they are supposed to imitate. This can defeat the entire purpose of such false containers, in that they cannot reliably conceal their contents, nor can they parlay immediate suspicions that they may contain other items.
SUMMARY
[0006] The invention, in its preferred embodiment, is a bulbous housing assembly that roughly takes the shape of an ammunition cylinder from a revolver handgun. The assembly has at least one removable cap, which is free to spin with respect to the cylinder portion of the container. As the cap spins, it makes the clicking sound of an actual revolver, as it would rotate from one chamber to the next. The realistic action and weight of the container itself gives a user the therapeutic experience of handling real firearm paraphernalia, while it avoids any suspicion of its purpose as a safe-keeper of valuables.
[0007] It is an object of this invention to provide a false container that appears to be a generic, yet valuable, item of its own. The item has its own appreciable value as a novelty, whether or not it is used to store anything at all. In fact it may not appear to be a container at all, but may have the feel of a solid article or assembly. It is not meant to look like anything common. The novelty of its appearance specifically indicates that it is not intended to conceal other items. It also avoids the otherwise likely appearance of imitating other trademarked products.
[0008] It is another object of this invention to provide a false container that possesses one or more elements, each having two or more sections, which normally appear as contiguous singular pieces of, or within, the assembly of the container itself. For example, the invention could take the form of an empty plastic housing that is made of two injection-molded halves, which are outfitted to look like say a roll of quarter-dollar coins, when assembled.
[0009] It is another object of this invention to provide an item that possesses a psychologically tangible association with handguns. Although the invention cannot be used as an accessory to any firearm, it has the look, the feel, and the nostalgic articulation of an actual revolver. The item, which is not subject to any regulations pertaining to real weapons, imparts a psychological appeal that is enough to provide users with the sensation of handling firearm paraphernalia without subjecting themselves to the inherent risks that would otherwise be involved.
[0010] It is still another object of this invention to provide a concealing container that possesses enough mass and inertia that it will be more likely to detract any noticeable effect from the jostling movement of less-heavy items within.
[0011] It is yet another object of this invention to provide a puzzle toy that, by its particular movement, is meant to be challenging to open.
DRAWING VIEWS
[0012] FIG. 1 shows the assembled invention in a front perspective view.
[0013] FIG. 2 shows the assembled invention in a rear perspective view.
[0014] FIG. 3 is a front perspective view of the Center Ring.
[0015] FIG. 4 is a perspective view of the Front Cap.
[0016] FIG. 5 is a perspective view of the Rear Cap.
[0017] FIG. 6 is a cross-section of the assembled invention.
[0018] FIG. 7 is a perspective view of a Signature Front Cap.
DESCRIPTION OF THE INVENTION
[0019] The invention, in this preferred embodiment, is made to resemble a revolving ammunition cylinder (from a six-shooter, for example). With this device, the Front Cap and Rear Cap are fixed to each other upon assembly, to form what we call a magazine. Together, though, they are free to spin inside a housing called the Center Ring.
[0020] The user holds the Center Ring with one hand, while turning a Cap with the other hand. The user contacts the bullet portions with his fingers, so as to provide grip. These bullet features could be omitted, so that the recesses provide even greater grip.
[0021] As the caps revolve within the housing, they tend to locate at one of six possible positions (just like the cylinder of a pistol revolver). The magazine is intended to appear as though there are six live bullets loaded into it, which appear to occupy the interior volume of the housing.
[0022] In FIG. 1 , the device 10 is shown as a primarily spherical assembly. The Front Tip 11 of each bullet can be seen in this view.
[0023] FIG. 2 , shows the same device, when viewed from the rear. In this view, the Rear Tip 12 of each bullet is visible. Now, although each “bullet” is comprises a front portion and a separate rear portion, together each will be referred to as a single bullet in this document, for convenience. Each portion can be either press-fit or bonded into place.
[0024] FIG. 3 shows the Center Ring 20 when viewed from the front. The interior of the Center Ring is cylindrical, with the exception of the Rear Lip 23 and the Front Lip 24 . Note that the Rear Lip possesses a number of notches, each called an Index 21 . Only three Indexes are visible in this view, but there are six total, equally spaced on the Rear Lip.
[0025] Also, note that there are two Slots 22 in the Front Lip directly across from each other.
[0026] Upon the exterior surface of the Center Ring are six Recesses 25 , which together enhance the appearance of the device to resemble a pistol cylinder. Each end of the Center Ring is defined by a Rim 26 .
[0027] FIG. 4 shows the Front Cap 30 . A Front Tip 11 of a bullet is one of three visible in this view. A Front Plastic Seal 36 is shown mounted to the Front Cap, which has an outer diameter slightly smaller than that of the Rim of the Center Ring. The Front Cap comprise two or more Posts, which rotably fasten it to the Center Ring. A single Post 32 is shown here with its narrower Stem 34 . The two Posts in this view of the Front Cap align with the two Slots in the Center Ring, upon assembly. The two Posts also align with two pins on the Rear Cap (which are shown in FIG. 5 ).
[0028] FIG. 5 shows the Rear Cap 40 . A Rear Tip 12 of a bullet is one of two visible in this view. A Rear Plastic Seal 46 is mounted to the Rear Cap, which has an outer diameter slightly smaller than that of the Rim of the Center Ring. The Fixed Pin 41 possesses a Snap Ring 43 , which is located about a groove on the Fixed Pin (shown in greater detail in FIG. 6 ). The Indexing Pin 42 , is shown with another Snap Ring 43 , a Spring 44 , and a Detent 45 . This Detent is shown approximately in the position it would be in, when the device is fully assembled.
[0029] FIG. 6 shows the complete device (in a bisecting cross-section). In this view, the inner workings of the can be seen more easily. The assembly comprises the Center Ring 20 , the Front Cap 30 , and the Rear Cap 40 .
[0030] The Posts 32 are press-fit into the body of the Front Cap. The Posts extend into the Center Ring and are kept within it by the Front Lip 24 of the Center Ring. Once the Front Cap is in place and rotated, the Front Cap is locked to the Center Ring. The Stem (see FIG. 4 ), with its smaller diameter, allows room for the Front Lip. The length of the Stem is slightly greater than the thickness of the Front Lip, to allow free rotation while limiting any movement other than rotation. The Front Plastic Seal 36 acts to reduce friction during rotation.
[0031] When assembling the device, the Posts can only pass the Front Lip of the Center Ring properly, through the Slots.
[0032] The Posts each comprise a disc-shaped Magnet 33 that is pressed into the Post 32 itself. The Magnets are installed to attract the Pins of the Rear Cap. Although the Pins are mechanically captured within the Posts, upon assembly, the Magnets help to keep the Post and Pin together. This is so that the Caps will tend to stay fixed to each other, even if the Posts are free to pass the Slots in the Center Ring. (The Slots are shown in FIG. 3 .)
[0033] The Rear Cap 40 is permanently located with the Center Ring 20 by the Snap Ring 43 on the Fixed Pin 41 . The Rear Cap is able to spin freely, but is tended by the Detent 45 to one of six Indexes 21 by the force of the Spring 44 . The Spring is held in place by a Snap Ring, which is fixed about a groove on the Indexing Pin 42 . The Rear Plastic Seal 46 acts to reduce friction during rotation.
[0034] Note that the detent mechanism could easily be located separate from the Indexing Pin 42 , and may even take the form of a commercial detent mounted so that its axis is radial to the device itself. In such a case, the Indexing Pin would be similar to the Fixed Pin 41 .
[0035] When the device is assembled, the Posts pass through the Slots, and onto the ends of the Pins. At that point, the Caps are held together by the force of the Magnets alone. (Ideally, an unauthorized person would not be aware that the Front Cap could be removed when in that position.) If and when the Caps are turned, then the Front Cap is physically kept onto the assembly by the Front Lip. Only when the Front Cap is in place through the Slots, can it be rotated to lock the Front Cap to the Center Ring. When the device is assembled, the Front Cap rotates with the Rear Cap as a single part.
[0036] FIG. 7 shows the Front Cap of an Alternate Embodiment 50 . In this view, the Signature (i.e. unique and asymmetric) Pattern of Posts 52 ensures that there is one and only one position (orientation) for the Front Cap when it can be removed from the Center Ring.
[0037] As with any embodiment, the position of the Front Cap, when it can be removed, can be marked by corresponding features on both the Cap and the Center Ring. These features can be as discreet, or as discrete, as necessary.
[0038] To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated.
[0039] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
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Disclosed are the working of a Spherical Locking Container 10 , which roughly takes the form an ammunition cylinder from a pistol revolver. The faux Bullets 11 give the appearance of solid and valuable device. The item generates commercial value as a novelty as well as a clever, well-constructed storage container.
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FIELD OF THE INVENTION
The present invention relates to hydroxyamines N-acyl derivatives with benzochroman or 2,3-dihydro-benzofuran carboxy acids and relative pharmaceutical composition for the therapeutic treatment of those CNS, vascular, cardiovascular, dermatologic and ophthalmic chronic and acute pathologies correlated to peroxidation and inflammation phenomena.
PRIOR ART DISCLOSURE
Biologic systems, and among them in particular cellular membranes, generally contain considerable quantities of unsaturated lipids, being susceptible of oxidative phenomena caused by free radicals produced in metabolic processes by the same cells.
Under physiologic conditions, cellular membranes have in any case a complex defence system protecting them from free radicals attack and from the consequent damage (D. Hallivell and J. M. Gutteridge, Free radicals in Biology and Medicine, Clarendar Press, Oxford, 1989). Among these systems biological molecules, having antioxidant activity, biologically active compounds are to be mentioned, whose Vitamin E is the most representative one. Even at low "in vivo" concentrations under physiologic conditions is in fact able to effectively act as scavenger, preventing peroxidative chain reactions between free radicals and membrane unsaturated lipids, which would bring to damages to the same membrane with consequent alterations of the cellular functionality. Tocopherols, heavy oils, widely distributed in the most common aliments have the same vitamin E-like activity.
Chemically speaking α-tocopherol is a 6-hydroxychroman compound substituted on methyl group, linked to a long aliphatic chain, its aromatic ring can react with free radicals oxidizing, thus preventing the oxidation of other molecules such as the above mentioned membrane lipids.
Pathologically speaking it is known that vitamin E deficiency states are often associated with an anomalous membrane lipids peroxidation and the antioxidant action, under this aspect and in general, becomes important for the integrity of different cellular types, being susceptible of oxidative phenomena. Vitamin E deficiency conditions are in fact directly correlated to hemolytic anemia, in which a defect in the lipidic oxidation at the expense of the red cell seems to exist, retrolental fibroplasia, bronchopulmonary dysplasia, namely all pathologies being sensitive to vitamin E treatment.
Furthermore, vitamin E deficit has been correlated to a platelet aggregation increase, which from the pathological standpoint corresponds to an increase of thrombosis risk. During the biosynthetic process of prostaglandins (PGE2 and PGF2), it induces in particular the formation of cyclic intermediates having short half life, the endoperoxides (PGG2, PGH2 and thromboxan), thus determining a platelet aggregation enhancement. The ability of vitamin E to reduce platelet aggregation can be explained by means of phospholipase A preventing thromboxan precursor release (Osky J. A., Hospital Practice, October 1977, pp 79-85). Vitamin E proved able to considerably protect the cells exposed against the attack of free radicals under conditions of damage having different origins.
In the damaged nervous tissue, consequent to different types of lesions ascribable to acute damage or to CNS neurodegenerative pathologies, Vitamin. E showing its scavenger activity on free radicals prevents the damage induced on the cellular neuronal membranes and limits the biochemical chain events conducting to tissue necrosis. For example a powerful neurotoxin of the dopaminergic system, N-methyl-4-phenyl-1,2,3,6 tetrahydropteridine (MPTP), causing dopaminergic cells death and inducing a Parkinson-like syndrome in different species of animals besides man, is sensitive to the effect of different antiperoxidants including vitamin E. The importance of peroxidative phenomena in neurodegenerative pathologies has recently found more than one confirmation. A red-ox systems alteration was in fact demonstrated (ferritin and glutathione reduction and Fe increase) accompanied by lipidic peroxidation in substantia nigra in Parkinsonian patients (C.01anow, Neurodegenerative disease research aims to combat oxidative stress, London, September 1992), whereas it was demonstrated that molecules having antiperoxidant activity, inhibit lipidic peroxidation induced by iron in Alzheimer patients' cerebral tissue (L. Williams, Neurodegenerative disease Research aims to combat oxidative stress, the above mentioned article) In addition molecules such as malonyldialdehyde, index of lipidic peroxidation, increase their plasmatic levels under ischemia conditions such as cerebral ictus, subarachnoid hemorrhage and spinal lesion; (Stroke, vol.16:1, 1985) or myocardial infarction (J. C. Dousset et al, Olin. Chim. Acta, 129: 319,1983). As a confirmation of that, rabbits under vitamin E deficit conditions exhibit a reduced mitochondrial Function and increased Formation of oxygen radicals accompanied by a diminished superoxide dismutase activity: in vitro experiments evidence that this phenomenon is at least partially reduced by vitamin E.
On the whole, these evidences induce to hypothesize a therapeutic effect of the antioxidants in the above mentioned pathologies, but peroxidative phenomena coming from free radicals, are also responsible for skin precocious "aging". Free radicals are produced by environment factors (radiolysis, u.v. photolysis, ozone and nitrogen monoxide), which every individual is exposed to. In particular u.v. radiations are also responsible for those cutaneous photobiologic damages, which seem to be at the base of cutaneous tumoral forms, being indeed sensitive to the therapy with vitamin E (Kanda et al., British Journal of Dermatology, 12(6): 771-776). These alterations described at the cutaneous level can reach other tissues such as collagen (J. H.Bowes, Biochimica Biophysica, 168:341-352, 1968), but most of all they involve sebaceous and sudoriferous glands, as a matter of fact the antiperoxidant effect might be important in preventing or treating phenomena correlated to irritating lipids secreted by damaged sebaceous and sudoriferous glands as a consequence of the bacterial activity in cutaneous pathologies such as acne. More recent experimental evidences show that also ophthalmic pathologies having vital aetiology, such as corneal herpes simplex and retinal infection caused by human citomegalovirus (blindness cause in AIDS patients), are sensitive to the effects of antioxidants.
It is also known that in most of the above cited pathologies an inflammatory state is associated to the peroxidation damage. In the inflammatory processes, a very important and up to now not very investigated role is played by a particular cellular population residing in tissues: mast cells. They begin the inflammatory process, after their activation through specific signals, by means of a massive release of numerous mediators locally active at the moment of the call the activation and migration from the vasal to the tissular compartment of the cellular population involved in the inflammatory and reparative process.
Mast cells present at the level of connective tissues, because of the action of the lesive stimulus, are subjected to an explosive degranulation with emission of histamine, heparin, leukotriens and PAF, but above all cytokins and in particular Tumor Necrosis Factor (TNF). This cytokin is an important mediator of inflammation, since on its turn it induces immunocompetent cells such as neutrophil cells and granulocytes to adhere to endothelial cells, and to degranulate, thus forming extremely reactive superoxide anions, as well as it induces a coagulation activation with possible thrombotic effects. Because of this crucial role mast cell population is now acknowledged as the effector system of inflammation. Mast cell is at the center of complex interactions among the nervous, endocrine and immune systems, because it is sensitive to signals of nervous origin, in particular the neuropeptides, which modify its activation condition, or to immune or endocrine stimuli, which are able to modify its function and/or its phenotype features. Therefore mast cell represents, at the cellular level, the moment of integration between the nervous system and the immune system, being its activation, under both physiologic and decidedly pathologic conditions, strictly controlled by both systems.
Although nothing is known at the mast cell level about the association between peroxidative phenomena and modulation of the agonist/antagonist system pertaining to mast cell degranulation the possibility to intervene pharmacologically by using compounds able to act effectively on both these systems is to be considered of the greatest importance.
As a matter of fact, notwithstanding the important assumptions giving evidence in favour of a potential use of vitamin E and its correlated compounds in the treatment of CNS, cardiovascular, as well as the above mentioned dermatologic pathologies, which, because of the degree of induced disability and of their great epidemiologic importance have a strong social impact, therapeutically speaking, a consolidated use of these compounds is not noticed. That is probably ascribable to the necessity to have compounds which, besides showing an antioxidant activity, exhibit other activities directed to prevent and to cure the formation of other vicious circles induced by the inflammatory state.
SUMMARY OF THE INVENTION
The present invention relates to N-acyl-derivatives of primary or secondary biologically acceptable hydroxyamines selected from:
aliphatic hydroxyamines, whose linear or branched alkyl chain has from 1 to 20 carbon atoms and is optionally substituted with at least one functional group selected from NH 2 and COOH or
heterocyclic hydroxyamines, whose ring has from 5 to 6 atoms and contains as the heteroatom at least one N atom, said heterocyclic ring being optionally substituted with at least one COOH group; with carboxylic acids having the following general formula (I): ##STR1## wherein X is a bivalent alkylenic or alkylidenic radical selected from the group consisting of: --CH 2 --, --CH 2 --CH 2 --, --CH═CH--,
R 1 is selected among the substituents as defined in one of the following classes:
A) hydrogen atom,
B) a phosphoryl radical,
C) --L--COOH wherein L is a bivalent radical selected from:
a) a linear or branched saturated or unsaturated alkylenic chain of from 1 to 20 carbon atoms, optionally substituted with at least one amino group, said amino group being optionally N-acylated with a C 1 -C 5 carboxylic acid, optionally substituted in the aliphatic chain with at least one hydroxy group;
b) an arylene,
c) a saturated or aromatic bivalent heterocyclic radical, whose ring has from 5 to 6 terms and containing at least one heteroatom selected from the group consisting of N, S and O;
D) --CO--M--COOH wherein M is a bivalent radical selected from:
a') a linear or branched alkylenic chain of from 1 to 20 carbon atoms, optionally containing at least one ethylenic unsaturation,
b') an arylene,
E) is a linear or branched alkyl radical of from 1 to 20 carbon atoms, optionally substituted with at least one aryl, or hydroxy groups;
F) R--CO--, wherein R is a linear or branched saturated or unsaturated alkyl radical of from 1 to 20 carbon atoms, optionally substituted with at least one --SH group;
R 2 , R 5 , R 6 equal or different from each other are selected from the group consisting of H, methyl, benzyl or terbutyl,
R 3 is chosen from H, methyl, ethyl and tertbutyl;
R 4 is --COOH, a linear or branched saturated or unsaturated aliphatic chain of from 1 to 20 carbon atoms or --W--COOH, wherein W is an alkylene radical of from 1 to 20 carbon atoms; provided that:
i) R 4 is always --COOH or --W--COOH when R 1 has one of the meaning as defined in one of the above mentioned classes A, B, E and F,
ii) when R 1 is =H, R 2 =R 5 =R 6 =CH 3 , R 4 =COOH, X=CH 2 --CH 2 , the hydroxyamine forming the N-acyl derivative must be different from ethanolamine.
In fact the Applicant has surprisingly found that the N-acyl derivatives of hydroxyamines with the above mentioned carboxylic acids of formula (I), not only maintain the antioxidant activity of the origin carboxylic acids, but they also have, if compared to these starting compounds, an enhanced antioxidant activity. Moreover these compounds are able to act as mast cell modulators, this action being particularly important in inflammatory states of neuroimmunogenic origin.
In addition it has been unexpectedly found that these compounds can inhibit the degenerative processes and neuronal death, which are in any case connected to acute and chronic pathologies involving oxidative and inflammatory processes.
The present invention further relates to pharmaceutical compositions containing as the active principle at least one of these derivatives in combination with suitable excipients and/or diluents for the therapeutic treatment of those acute or chronic CNS, vascular, cardiovascular, dermatologic and ophthalmic pathologies correlated to peroxidation and inflammation phenomena.
DETAILED DESCRIPTION OF THE INVENTION
The characteristic and advantages of the new N-acyl derivatives of hydroxyamines with compounds correlated to vitamin E, being active both as antioxidants and as modulators of mast cells hyperactivation, and which can therefore be utilized for the treatment of pathologies, in which it is important to effectively combine both these actions in order to prevent the formation of vicious circles involved in cellular degeneration, will be better understood during the course of the present detailed description. When R 1 in the carboxylic acids of formula (I) used to prepare the N-acyl derivatives of the present invention belongs to class C it is preferably selected from ##STR2## acids.
When R 1 assumes the meanings as defined in class D it is preferably selected from the group consisting of: HOOC--(CH 2 ) 7 --CO--, ##STR3##
When R 1 assumes the meanings as defined in class E it is preferably selected from the group consisting of: methyl, ethyl, benzyl, octadecyl, 2-hydroxyethyl.
When R 1 assumes the meanings as defined in class F, it is preferably ##STR4##
Because of their biological activities these compounds can be advantageously administered for the above mentioned pathologies, and in particular hemolytic anemia, but also pathologies of ischemic origin (cerebral ictus, subarachnoid hemorrhage, spinal damage), and pathologies of CNS degenerative origin, such as Parkinson and Alzheimer diseases, cardiovascular pathologies including myocardial infarction and vasculopathies with a thrombotic risk component.
In addition cutaneous pathologies connected to oxidative phenomena: such as photolysis precocious cutaneous aging, eczema, systemic lupus erithematosus, lichen, sebaceous and sudoriferous glands dysfunction and their correlated phenomena, and infections of vital origin such as corneal herpes simplex, citomegalovirus retinal infections are to be cited.
The N-acyl derivatives of hydroxyamines such as monoethanolamine, diethanolamine, propanolamine, 4-hydroxyproline, L-serine are preferred, said hydroxyamines are optionally O-acetylated.
For illustrative purposes we take into account, in addition to vitamin E, two molecules already known for their antiperoxydative effect: 6-hydroxy-2,5,7,8 tetramethylchroman-2-carboxylic acid that can be considered a "bridge" between the natural molecule and the synthetic antioxydant (W. M. Cort et. al., Food Technology, pp 46-50, November 1975) and a benzofuran: 5-hydroxy-4,6,7-trimethyl-2,3-dihyrobenzofuran-2-acetic acid (BFA) (A. Bindoli et al. Pharmacological Research 24, 4: 369-375,1991), which a new family of compounds for N-acylation with monoethanolamine is derived from.
In order to illustrate a possible application of the invention, the following molecules are considered, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid 3-propanolamide, 2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)-acetic acid 2-hydroxyethylamide, 6-acetoxy 2,5,7,8 tetramethyl-chroman-2-(2-acetoxyethyl)-carboxamide, N-[2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)acetyl]-propanolamine, D-α-tocopherol acid succinate 2-hydroxyethylamide described as an example of a series of vitamin E hydroxyamides.
Other hydroxyamines N-acylderivatives particularly preferred are those prepared from the following carboxylic acids derived from benzochroman:
2-(6-hydroxy-2,5,7,8-tetramethylchroman)-acetic acid;
3-(6-hydroxy-2,5,7,8-tetramethylchroman)-propionic acid;
2-(6-hydroxy-2,7,8-trimethylchroman)-acetic acid;
6-hydroxy-2 ethyl-5,7,8-trimethylchroman-carboxylic acid;
6-hydroxy-5,7,8-trimethylchroman-carboxylic acid;
6-hydroxy-2-methylchroman-carboxylic acid;
6-hydroxy-2-methyl-7-terbutylchroman carboxylic acid;
6-hydroxy-2-methyl-5,7-diterbutylchroman carboxylic acid;
6-hydroxy-2,7,8-trimethylchroman-carboxylic acid;
6-hydroxy-2,5,7,8-tetramethylchroman (3-4)ene-carboxylic acid;
2-(6-hydroxy-2,5,7,8-tetramethylchroman (3-4)ene)-acetic acid;
and their derivatives having the hydroxy group in the 6 position in the aromatic ring substituted with the groups above defined in the A, B, C, D, E and F classes;
or with the following carboxylic acid derived from (2,3-dihydro)benzofuran:
2-(2,3-dihydro-5-Acetoxy-4,6,7 trimethylbenzofuranyl)-acetic acid.
Reported are hereinbelow for illustrative but not limitative purposes some preparation examples of N-acyl derivative according to the present invention.
EXAMPLE 1
Preparation of 2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)-acetic acid 2 hydroxyethylamide or N-[2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl]ethanolamine
2.87 g (21 mmoles) of isobutylchloroformiate dissolved in 50 ml THF, are added slowly drop by drop in 30 minutes to a mixture of 4.73 g (20 mmoles) 2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)-acetic acid and 2.13 g (21 mmoles) triethylamine dissolved in 100 ml anhydrous THF and kept under stirring at -10° C. The mixture is maintained under stirring at -10° C. for 2 hours and afterwards at 0° C. for 15 hours.
1.8 g ethanolamine are slowly added drop by drop in 30 minutes. After further 20 hours stirring at 0° C., the mixture thus obtained is treated with 300 ml of a saturated aqueous solution NaCl and extracted 3 times with 100 ml ethyl acetate, the extracts are collected and evaporated to dryness. The residue is dissolved in 30 ml 80% acetic acid and lyophilized.
The reaction yield is about 90%.
2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)-acetic acid 2 hydroxyethylamide physical-chemical characteristics are the following:
______________________________________physical state: whitish amorphous powderraw formula: C.sub.15 H.sub.21 NO.sub.4molecular weight: 279.34elemental analysis: C = 64.5%; H = 7.58%; N = 5.01%; O = 22.91%;solubility in org. solv.: >10 mg/ml in ethanol; DMSO, chloroform.water solubility: slightly soluble.melting point: /TLC: eluent chloroform/methanol/water/ 28% NH.sub.3 80:25:2:1 Rf = 0.70______________________________________
EXAMPLE 2
Preparation of D-α-tocopherol acid succinate 2-hydroxyethylamide.
2.87 g (21 mmoles) of isobutylchloroformiate dissolved in 50 ml THF, are added slowly drop by drop in 30 minutes to a mixture of 10.6 g (20 mmoles) D-α-tocopherol acid succinate and 2.13 g (21 mmoles) triethylamine dissolved in 100 ml anhydrous THF and kept under stirring at -10° C.
The mixture is maintained under stirring at -10° C. for 2 hours and afterwards at 0° C. for 15 hours.
1.8 g ethanolamine are slowly added drop by drop in 30 minutes. After further 20 hours stirring at 0° C. the suspension thus obtained is filtered, the precipitate is disregarded and the liquid is evaporated to dryness; the residue is treated with 100 ml of an aqueos solution of NaHCO 3 and extracted with 200 ml ethylacetate and the organic layer is washed with 50 ml water, dried on sodium sulfate and finally evaporated to dryness, the residue is solubilized in 100 ml hot hexane and crystallized; the obtained waxy solid is separated by centrifugation, washed three times with 50 ml hexane and finally dried under high vacuum.
The reaction yield is about 90%.
D-α-tocopherol acid succinate 2-hydroxyethylamide physical-chemical characteristics are the following:
______________________________________physical state: whitish waxy powderraw formula: C.sub.35 H.sub.59 NO.sub.5molecular weight: 573.86elemental analysis: (calculated) C = 73.26%; H = 10.36%; N = 2.44%; O = 13.94%; (found) C = 72.34%; H = 10.52%; (N = 2.49%; O = 13.63%.solubility in org. solv.: >10 mg/ml in ethanol and chloroform.water solubility: slightly soluble.melting point: /TLC: eluent ethyl acetate Rf = 0.20______________________________________
EXAMPLE 3
Preparation of 6-acetoxy-2,5,7,8-tetramethyl-chroman-2-(2-acetoxyethyl)-carboxyamide
10 ml of acetic anhydride are added to 2.93 g (10 mmoles) 6-hydroxy-2,5,7,8-tetramethylchroman-2-(2-hydroxyethyl)-carboxyamide solubilized in 50 ml anhydrous pyridine and maintained under stirring at 4° C.
The mixture is maintained under stirring at 4° C. for 1 hour, afterwards at 45° C. for 15 hours and finally evaporated to dryness under vacuum. The residue is dissolved in 50 ml cool water and extracted three times with 50 ml ethyl acetate; the organic phase is washed twice with 50 ml 0.1M HCl, twice with 50 ml 5% NaHCO 3 , twice with 50 ml water and finally collected and dried on Na 2 SO 4 and evaporated to dryness. The residue is solubilized in 10 ml terbutyl alcohol and lyophilized.
The reaction yield is about 92%.
The physical-chemical characteristics of 6-acetoxy-2,5,7,8-tetramethylchroman-2-(2-acetoxyethyl)-carboxyamide are the following:
______________________________________physical state: deliquescent amorphous powderraw formula: C.sub.20 H.sub.27 NO.sub.6molecular weight: 377.44elemental analysis: C = 63.65%; H = 7.21%; N = 3.71%; O = 25.43%;solubility in org. solv.: >10 mg/ml in ethanol;water solubility: slightly soluble.melting point: /TLC: eluent ethyl acetate Rf = 0.74______________________________________
EXAMPLE 4
Preparation of N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxyl)-propanolamine.
2.87 g (21 mmoles) of isobutylchloroformiate dissolved in 50 ml THF, are added slowly drop by drop in 30 minutes to a mixture of 5.00 g (20 mmoles) 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid and 2.13 g (21 mmoles) triethylamine dissolved in 100 ml anhydrous THF and kept under stirring at -10° C.
The mixture is maintained under stirring at -10° C. for 2 hours and afterwards at 0° C. for 15 hours. 2.25 g propanolamine are then slowly added drop by drop in 30 minutes. After further 20 hours stirring at 0° C., the obtained suspension is filtered, the precipitate is discarded and the liquid is evaporated to dryness; the residue is treated with 300 ml of a saturated aqueous solution of NaCl and extracted 3 times with 100 ml ethyl acetate, the extracts are collected and evaporated to dryness. The residue is crystallized from 100 ml terbuthylmethyl ether; the product is separated by filtration washed 3 times with 10 ml terbuthylmethyl ether and finally dried under high vacuum.
The reaction yield is about 92%.
The physical-chemical characteristics of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid 3-hydroxypropylamide are the following:
______________________________________physical state: whitish crystalline powderraw formula: C.sub.17 H.sub.25 NO.sub.4molecular weight: 307.39elemental analysis: C = 66.42%; H = 8.20%; N = 4.56%; O = 20.82%;solubility in org. solv.: >10 mg/ml in ethanol; DMSO, chloroform.water solubility: slightly soluble.melting point: 112-114°C.TLC: eluent chloroform/methanol/water/ 28% NH.sub.3 80:25:2:1 Rf = 0.79______________________________________
EXAMPLE 5
Preparation of N-[2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)-acetyl]-propanolamine.
2.87 g (21 mmoles) of isobutylchloroformiate dissolved in 50 ml THF, are slowly added drop by drop in 30 minutes to a mixture of 4.73 g (20 mmoles) 2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)-acetic acid and 2.13 g (21 mmoles)triethylamine dissolved in 100 ml anhydrous THF and kept under stirring at -10° C. The mixture is maintained under stirring at -10° C. for 2 hours and afterwards at 0° C. for 15 hours. 2.25 g propanolamine are then slowly added drop by drop in 30 minutes. After further 20 hours stirring at 0° C. the obtained suspension is filtered, the precipitate is discarded and the liquid is evaporated to dryness; the residue is treated with 300 ml of a saturated aqueous solution NaCl and extracted 3 times with 100 ml ethyl acetate, the extracts are collected and evaporated to dryness. The residue is crystallized from 100 ml terbuthylmethyl ether; the product is separated by filtration washed 3 times with 10 ml cool terbutylmethyl ether and finally dried under high vacuum.
The reaction yield is about 90%.
The physical-chemical characteristics of 2-(2,3-dihydro-5-hydroxy-4,6,7-trimethylbenzofuran)-acetic acid 3-hydroxypropylamide are the following:
______________________________________physical state: whitish amorphous powderraw formula: C.sub.16 H.sub.23 NO.sub.4molecular weight: 293.37elemental analysis: C = 65.51%; H = 7.90%; N = 4.77%; O = 21.81%;solubility in org. solv.: >10 mg/ml in ethanol; DMSO, chloroform.water solubility: slightly soluble.melting point: /TLC: eluent chloroform/methanol/water/ 28% NH.sub.3 80:25:2:1 Rf = 0.81______________________________________
BIOLOGICAL ACTIVITY
The experiments, hereinbelow reported, have the purpose to evaluate the antiperoxidative effect of these compounds on the rat liver microsomes whose membrane phospholipids are peroxidized in two different ways and to verify the effect on an in vitro model of cells death mediated by oxidative stress referable to cellular damages occurring after a damage in the CNS.
Finally the anti-inflammatory activity is evaluated by modulation of the mast cells hyperactivation, in a neurogenic inflammatory model whose characteristics are described in the European patent applications No. 0550 006 and 0550 008 in the name of the same assignee.
In vitro biological activity
1. In vitro antiperoxidative activity of N-[2-(5-hydroxy-4,6, 7-trimethyl-2,3-dihydpobenzofuran)-acetyl]ethanolamine D-α-tocopherol acid succinate 2-hydroxyethylamide, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid 3-hydroxy propylamide, 2-(3,4 dihydro-5-hydroxy-4,6,7-trimethyl benzofuran-acetic acid 3-hydroxypropylamide and 6-acetoxy-2,5,7,8-tetramethylchroman-2-(2-acetoxyethyl)carboxyamide in comparison with that of Vitamin E, evaluated on rat liver microsomes.
Materials and methods:
Mitochondria preparation:
Rat liver mitochondria are insulated in a saccharide buffer 0.25M in 15 mM Hepes/10 mM Tris at pH=7.4 according to the method described by Myers and Slater (Myers D. K., Slater E. C., Biochem. J. 1957; 67: 558-72).
Before the final resuspension mitochondria ape washed with 0.125M KCl containing 15 mM Hepes/10 mM tris at pH=7.4. Rat liver microsomes are prepared as described by Ernster and Nordenbrand (Ernster, Nordenbrand K. Methods Enzymol. 1967, 10:574-80).
Peroxidant system:
a) 0.5 mg rat liver micposomial proteins are incubated at 30° C. for 15 minutes in a medium containing: 125 mM KCl, 20 mM Hepes-Tris buffer at pH=7.4, 0.1 mM NADPH, 10 μM Fe +2 , 100 μM ADP or:
b) 20 mM Hepes-Tris buffer pH=7.4, 0.5 mM cumene hydroperoxide in the presence or in the absence of the compounds to be tested. The trials after incubation are interrupted with 1 ml 35% TCA which 30 mg BHT and 1 ml 1% TBA (thiobarbituric acid) have been added to. Subsequently the incubation is carried out for 15' at 90° C. in order to allow the development of the coloured adduct.
Parameters:
A common oxidation product, malonyldialdehyde (MDA), to the two oxidant systems described in (a) and in (b), is measured.
The formed MDA is evaluated by spectrophotometry at 532 nm and calculated by using a molar extinction coefficient of 156.000 (Buege J. A. and Aust S. D., Methods Enzymol., 52, 302-310, 1978).
Compound solubilization:
The tested compounds are solubilized in the culture medium up to the desired concentrations (see tables 1-3).
Results:
1A--The compound N-(2-(5-hydroxy-4,6,7-trimethyl-2,3 dihydrobenzofuran)acetyl)ethanolamine is able to inhibit the peroxidation induced by NADPH/Fe +2 /ADP (a) and by cumene peroxide (b) with a dose/effect relationship comprised between 10 and 50 μM and its effect is consistently higher than that of the comparison product namely the corresponding acid (Tab. 1-A and 3).
As negative control vit. E acetate is used, as the protected phenol group renders this compound inactive in the in-vitro systems.
1B--The experiments indicate that the three tested compounds are able to inhibit the peroxidation induced on insulated systems. In particular the compound described in table (2) shows an analogous activity to that of Vitamin E after 60 minutes incubation.
In fact, similarly to vitamin E acetate in this molecule the hydroxy group in position 6 necessary for the antiperoxidant activity is involved in a bond which can be broken by enzymatic route.
The compounds whose activity is reported in table 1-B exhibit their typical protective effect even at concentrations 4 or 5 times lower than that of the antioxidant Vitamin E, which is taken as reference.
Table.1
A N-(2(5-hydroxy-4,6,7-trimethyl-2,3 dihydrobenzofuran acetyl)ethanolamine compared with the starting compound 5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran-2-acetic acid in rat liver microsomes. As peroxidant agent NADPH/Fe +2 /ATP is used. As oxidation index the formation of malonyldialdehyde (MDA) is measured (nmoles/mg protein).
______________________________________ peroxidationCompounds MDA inhibition(μM) (nmoles/mg prot.) (%)______________________________________Control 42.5 05-hydroxy-4,5,6-trimethyl-2,3-dihydrobenzofuran-2-acetic acid10 44.19 020 37.3 12N-(2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)acetyl)ethanolamine10 33.5 2120 21.3 49Vit. E acetate10 51.08 020 49.34 0______________________________________
B In vitro antiperoxidant activity measured as malonyldialdehyde (MDA) formation of N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxy)-propanolamine, N-[2-(2,3-dihydro-5-hydroxy-4,6,7-trimethyl-benzofuran)-acetyl]-propanolamine, 6-acetoxy-2,5,7,8-tetrammethylchroman-2-(2-acetoxy-ethyl)-carboxamide, incubated at different concentrations with respect to that of Vitamin E.
______________________________________ MDA PeroxidationCompound (nmoles/mg/ Inhibition(μM) protein) (%)______________________________________Vit. E 10 42.27 7.7 20 40.03 13.5 40 21.80 52.9 60 12.34 73.3 80 2.40 94.8100 2.0 95.7N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxy)-propanolamine 10 28.96 37 20 1.61 95.5 40 1.07 97.7 60 1.04 97.7 80 1.07 97.7100 0.30 99.3Control 46.27 0Vit. E 10 37.20 ± 1.9 12.5 ± 4.5 20 33.15 ± 0.4 22.0 ± 1.0 40 22.95 ± 2.5 46.0 ± 6.0 60 8.50 ± 2.9 80.0 ± 7.0 80 2.55 ± 1.7 94.0 ± 4.0N-[2-(2,3-dihydro-5-hydroxy-4,6,7-tetramethyl-benzofuran)-acetyl]-propanolamine. 10 32.32 ± 0.4 24.0 ± 1.0 20 17.87 ± 2.9 58.0 ± 7.0 40 2.57 ± 1.3 94.0 ± 3.0 60 2.10 ± 1.2 95.0 ± 3.0 80 2.54 ± 1.3 94.0 ± 3.0Control 42.50 ± 2.4 0Vit. E 2.5 35.9 4.1 5 31.1 17.2 10 28 25.2 20 24.6 34.26-acetoxy-2,5,7,8-tetra-methylchroman-2-(2-acetoxyethyl)-carboxamide 2.5 28.8 23.1 5 21.8 41.6 10 17.2 53.8 20 14.1 62.1Control 37.4 0______________________________________
Table. 2
ADP/NADPH/Fe microsomial peroxidation: antiperoxidase activity of D-α-tocopherol acid succinate 2-hydroxyethylamide as a function of the preincubation time in comparison with those of Vitamin E acetate and Vitamin E. All the compounds are incubated at 40 μM concentration.
The antiperoxidase activity is measured as % of inhibition of malonyldialdehyde formation.
______________________________________Compounds preincubation time peroxidation inhibition(μM) (minutes) (%)______________________________________Vit. E (40) 0 39.15 15 39.90 30 39.35 45 38.75 60 40.90Vit. E acetate (40) 0 1.90 15 18.20 30 28.95 45 35.80 60 40.35D-α-tocopherol acid 0 1.40succinate 2-hydroxy- 15 17.30ethylamide (40) 30 29.50 45 37.90 60 40.90______________________________________
Table 3
In vitro antiperoxidant activity of the compound N-(2-(5hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)acetyl)ethanolamine compared with the starting compound 5-hydroxy-4,5,6-trimethyl-2,3-dihydrobenzofuran-2-acetic acid measured in rat liver microsomes. As peroxidant agent 0.5 mM cumene hydroperoxyde is used. As oxidation index the formation of malonyldialdehyde (MDA) is measured (nmoles/mg protein).
______________________________________ peroxidationCompounds MDA inhibition(μM) (nmoles/mg prot.) (%)______________________________________Control 12.85-hydroxy-4,5,6-trimethyl-2,3-dihydrobenzofuran-2-acetic acid20 9.25 2850 7.5 42N-(2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydro-benzofuran)acetyl)ethanolamine20 6.84 4750 2.5 80Vit. E acetate20 14.29 050 11.57 0______________________________________
2. In vitro protective effect of N-[2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl]ethanolamine derivatives evaluated on rat cerebellar granular cell cultures.
Materials and methods:
Primary neuron cell cultures:
Primary cerebellar granular cell cultures are prepared from 8 days old Sprague-Dawly rats. Neurons are grown on 35 mm plates for 7-8 days. The cultures thus treated are granular for more than 95% and less than 5% of glial cells is present (F. Vaccarino et. al. Proc. Natl. Acad. Sci. 84:8707-8711, 1987). Glial cells proliferation is prevented by cytosine arabinose-furanoside.
Cells are washed in Locke solution free from Mg 2+ then replated in the conditionned culture medium.
Treatment with the tested compounds:
Mother solutions at millimolar concentrations of N-(2-(5-hydroxy-4,6,7-trimethyl-2,3-dibenzofuran)-acetyl) ethanolamine are prepared using small amount of chloroform. The solution is diluted serially up to 10, 20 and 50 μM. The compounds at the desired concentrations are added to the cells at 37 ° C.; after 15' 50 μM glutamate free from Mg 2+ is added For 15 minutes at 22 ° C.
The cells are then washed 3 times with Locke solution, then added to the original culture medium and maintained at 37 ° C. in 5 % CO 2 for 24 hours.
Parameters:
The cellular survival is measured by using a fluorescence microscope.
Results:
The compound N-(2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl)ethanolamine is able to protect against the glutamate exogenous neurotoxicity in primary cells cultures of cerebellar neurons according to a dose-effect relationship as reported in the following Table 4.
Table. 4
Protective effect of N-(2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl)ethanolamine at different concentrations (μM) against (50 μM) glutamate toxicity in vitro in primary neuronal cultures of cerebellar granules.
______________________________________Compound cell survival(μM) (%)______________________________________Control 100Glutamate (Glu)50 3Glu+N-(2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl)-ethanolamine.10 3320 5050 85______________________________________
3.5 mM glutamate (Glu) cytotoxicity in glioma C6 cultures: protective effect of compounds D-α-tocopherol acid succinate N-2-hydroxy-ethylamide+N-[2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl]ethanolamine; 6-acetoxy-2,5,7,8-tetramethylchroman-2-(2-acetoxyethyl)-carboxamide; N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxy)-propanolamine; N-[2-(5-hydroxy-4,5,6-trimethyl-2,3-dihydrobenzofuran)-acetyl]propanolamine compared to that of 6-hydroxy-2,5,7,8-tetramethyl carboxylic acid.
Materials and methods:
cells preparation:
C6 glioma cells cultures are plated in 24 wells plates in Eagle culture medium which 10% FCS ape added to; (glutamate and cysteine nominal concentrations are respectively 0.2 mM and 0.05 mM) and treated with 5 mM glutamate for 24 hours.
In C6 glioma cultures, as in primary astrocytes, the glutamate uptake is widely mediated by sodium dependent mechanisms having higher affinity.
By contrast cystein enters cells with mechanism being completely independent from sodium.
At high concentrations glutamate compete with the cystein uptake systems by a pattern independent from sodium, causing a cystein intracellular depauperation and a consequent glutathione deficiency, an important protective agent against oxidative stress under physiological conditions, followed by cellular degeneration (Y. Cho and S. Bannai, J. Neurochem. 55: 2091-2097, 1990; T. H. Murphy et al. Neuron 2: 1547-1558, 1989).
Solubilization of the tested compounds:
The tested compounds and glutamate are dissolved in DMSO to form a 30 mM mother solution and are subsequently diluted to 200, 30, 10, 3, 1 and 0.3 μM concentrations.
Parameters:
The cellular survival is measured 24 hours after glutamate treatment and quantified by colorimetric analyses with MTT.
Results:
The treatment with 5 mM glutamate for 24 hours causes 90% cellular degeneration.
The results reported in Table 5 show that the compounds according to the present invention having antioxidant activity exhibit a powerful protective effect against the glutamate cytotoxic damage, mediated by free radicals, according to a dose-effect relationship, when administered contemporaneously to glutamate.
The tested compounds are about 10 times more effective if compared to 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid used as the reference compound as reported in the following Table 5.
Table.5
5 mM Glutamate (glu) cytotoxicity in glioma C6 cultures: protective effect of the compounds: D-α-tocopherol acid succinate N-2-hydroxyethylamide, N-[2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl]-ethanolamine; 6-acetoxy-2,5,7,8-tetramethylchroman-2-(2-acetoxyethyl) carboxamide; N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxyl)-propanolamine; N-[2-(5-hydroxy-4,5,6-trimethyl-2,3-dihyydrobenzofuran)-acetyl]-propanolamine, compared to that of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid.
______________________________________ Concentration % CellTreatment (μM) survival______________________________________Glutamate 7Glu + 6-hydroxy-2,5,7,8- 10 7tetramethylchroman-2- 30 37carboxylic acid 100 94Glu+Nr[2-(5-hydroxy-4,6,7- 1 13trimethyl-2,3-dihydrobenzofuran)- 3 88acetyl]-ethanolamine. 10 89Glu+D-α-tocopherol acid 10 10succinate N-2-hydroxyethylamide 30 80Glu+6-acetoxy-2,5,7,8- 1 17tetramethylchroman-2-(2- 3 40actoxyethyl)-carboxamide 10 82Glu+N-(6-hydroxy-2,5,7,8- 1 10tetramethylchroman-2-carboxyl)- 3 94propanolamine 10 90Glu+N[2-(5-hydroxy-4,6,7- 1 8trimethyl-2,3-dihydrobenzofuran)- 3 66acetyl]-propanolamine 10 91______________________________________
4. Protective effect of the compounds: N[2-(5hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl]-ethanolamine; 6-acetoxy-2,5,7,8-tetramethylchroman-2-(2-acetoxyethyl)carboxamide; N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxy)-propanolamine; N-[2-(5-hydroxy-4,5,6-trimethyl-2,3-dihydrobenzofuran)-acetyl]propanolamine, compared to that of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, against glutamate cytotoxicity in granular cerebellar cell cultures.
Materials and Methods
Cultures preparation:
Granular cells are prepared from 8-9 days old mice cerebellum BalbC and plated on polylysine substrate in 35 mm plates, 2.5×10 6 cells/plate in H-EBM+25 mM KCl+50 μg/ml Glu+10% FCS. Cytotoxicity is induced treating the cells for 24 hours with 2 mM L-glutamate in the presence of 5% FCS.
Compounds solubilization:
The tested compounds are solubilized in DMSO at a concentration of from 1 to 100 μM.
Results:
In the neuronal cells, glutamate binds not only the sites of the excitatory amino acid, but also the chloro-dependent transport sites cells inhibited by quisqualate and cysteine. Neuronal cells cultures are sensitive to the cytotoxic effects of glutamate mediated by the chloro-dependent transport. Cytotoxicity is directly proportional to its capacity to inhibit cystein uptake: the presence of glutamate causes a glutathione level reduction and an intracellular peroxides accumulation with consequent oxidative stress and cellular death (T. H. Murphy et al., Glutamate Toxicity in a neuronal cell lione involves inhibition of cysteine transport leading to oxidative stress, Neuron, vol.2:1547-1558, 1989). The same cytotoxic mechanisms by competitive inhibition of cysteine uptake glutamate are present in neuronal cell cultures and in particular immature neuronal cells, not having the synthetic mechanisms of the cysteine obtained from methionine, are considerably vulnerable (T. H. Murphy et al., Immature cortical neurons are uniquely sensitive to glutamate toxicity by inhibition of cysteine uptake; Faseb J., 4:1624-1633, 1990).
The treatment of immature granular cerebellar cells for 24 hours with 2 mM glutamate induces death in about 60+70% of these cells.
The cotreatment with the compounds of the present invention at concentrations comprised between 1 and 30 μM protects against cellular death caused by intracellular peroxide accumulation according to a dose-effect relationship. The activity of the new compounds is about one magnitude order higher than that of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid taken as the reference compound.
Table.6
2 mM Glutamate (Glu) cytotoxicity in immature granular cerebellar cells: protective effect of the co-treatment of the compounds: N-[2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)-acetyl]-ethanolamine; 6-acetoxy-2,5,7,8-tetramethylchroman-2-(2-acetoxyethyl) carboxamide; N-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxy)-propanolamine; N-[2-(5-hydroxy-4,5,6-trimethyl-2,3-dihydrobenzofuran)-acetyl]-propanolamine compared to that of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid.
______________________________________ Concentration % CellularTreatment (μM) survival______________________________________Glutamate 30Glu+6-hydroxy-2,5,7,8- 10 43tetramethylchroman-2- 50 54carboxylic acid 100 84Glu+N-[2-(5-hydroxy- 1 314,6,7-trimethyl-2,3-dihydro- 3 40benzofuran)-acetyl]- 10 94ethanolamine.Glu+6-acetoxy-2,5,7,8- 1 49tetramethylchroman-2-(2-acetoxy- 10 60ethyl)-carboxamide. 30 77Glu+N(6-hydroxy-2,5,7,8- 1 39tetramethylchroman-2-carboxy) 3 60propanolamine 10 77Glu+ N-[2-(5-hydroxy- 1 524,5,6-trimethyl-2,3- 10 83dihydrobenzofuran) 30 86acetyl]-propanolamine.______________________________________
In vivo Biological Activity
1. In vivo antidegranulating activity in rat mast cells.
Materials and methods
2 weeks old Sprague Dawley rats supplied by Charles River Calco 2 weeks old are treated by subcutaneous injection with N-(2-(5-hydroxy-4,6,7-trimethyl-2,3-dihydrobenzofuran)acetyl)ethanolamine and D-α tocopherol acid succinate N-hidroxyethylamide at 20 mg/kg concentration. The pharmacological treatment is preceded (20 min. before) by the degranulating stimulus induced by P substance (10 -6 M) injected in the auricular pinna. After 20 minutes from the degranulating stimulus, the animals are sacrificed. Their tissues are then taken (auricular pavilion) for the morphological aspect analysis of the mast cells residing in the connective tissues after fixation and coloration with toluidine blue.
Parameters:
The inhibition level of the mast cells degranulation in the animal tissue treated with the tested compounds in comparison with the animals treated only with the degranulating agent is considered as the parameter of the biological activity.
Results:
The morphological analysis show that substance P induces mast cells degranulation in 85-95% of the numbered mast cells (about 600-800/field and that this degranulation is, at least partially, inhibited by the tested compounds, (Table 7).
Table 7
Mast cells antidegranulating activity in vivo, induced by substance P: inhibitory effect of derivatives N-(2-(5-hydroxy-4,6,7- trimethyl-2,3-dihydrobenzofuran)-acetyl)ethanolamine and D-α-tocopherolo s.c. administered at a dose of 20 mg/kg.
______________________________________Compound inhibition %______________________________________P substance + N-(2-(5-hydroxy- 19*4,6,7-trimethyl-2,3-dihydrobenzofuran)-P. substance + D-α tocopherol 38.5acid succinate N-hydroxyethyl amide.______________________________________ *the inhibition percentage is calculated considering that the effect of the substance P is maximum (100% of mast cells degranulation).
CONCLUSIONS
The results reported in the various experiments show that the derivatives described in the present invention are able to perform a specific antioxidant effect at concentrations about five times lower than those of the origin compounds and to protect against exogenous glutamate cytotoxicity in suitable in vitro models of neuronal and non neuronal cultures, independently from their higher or lower sensitivity to the damage itself, and therefore they can be associated to the cellular degeneration consequent to both acute and chronic damages; moreover they are able to limit the mast cells degranulation process. These effects can be advantageously utilized in the therapy of pathologies having peroxidative and inflammatory components during the clear phase, but also for preventive purposes, under risk conditions.
It is useful to remind that the doses and the pharmacological treatment period must be different, distinguishing therapies in the acute phase of CNS acute pathologies (cerebral ictus, spinal injury, cranial trauma and subarachnoid hemorrhage) as well as those of the cardiovascular system (myocardial infarction, thrombosis), without overlooking the prophylactic therapy in "risk" patients, namely subjects with previous cerebral transient ischemic attacks (TIA), anginous subjects having a periodically reduced coronary flow or those having thrombotic risk; to these pathologies recurrent forms are also to be added such as migraine and epilepsy. To the therapy/prophylaxis of acute, subacute and recurrent forms, the therapy of chronic neurodegenerative pathologies especially of the CNS such as Parkinson disease, Alzheimer disease as well as less serious cognitive deficiency can be advantageously treated with the compounds of the present invention. To a prolonged and cyclically repeated treatment, with the compounds of the present invention, patients affected by cutaneous and collagen pathologies are also subjected, these pathologies being associated to a premature aging due both to genetic and environmental causes or in any case connected to peroxidative and inflammatory phenomena such as exanthematous lupus erythematosus, lichen, psoriasis, dermatitis seborrheica, acne, eczema, and pathologies having a vital etiology such as corneal herpes simplex and cytomegalovirus retinal infection, as well as phenomena due to the alteration of sebaceous and sudorifearous glands secretion, including bromhidrosis, which can have a regression, thanks to the antiperoxidant/anti-inflammatory effect.
For these pathologies, both the therapeutic use by oral and parenteral (intravenous, intramuscular and subcutaneous) systemic route, topical (cutaneous and corneal), transdermic and intradermic route is encompassed. The necessary dose to have the therapeutic effect depends on the considered pathology the weight and age of the patient. Preferred therapeutic ranges are comprised between 1 and 100 mg/kg preferably between 5 and 30 mg/kg for varying periods and in any case not shorter than 30 days, depending on the specific pathology.
Compositions containing as the active principles the compounds described in the present invention, comprise all the formulations suitable for the administration of the product by the most effective route, depending on the considered pathologies and in any case all the pharmaceutically acceptable excipients, in particular solutions for injective oily formulations optionally, to be prepared at the moment of the use starting from lyophilized products), creams, ointments and lyophilized powder (optionally alcoholic) or solutions to be utilized also in vaporized form are mentioned; for the oral formulations powders are to be preferred, in the form of tablets, dragees, capsules, pearls, or liquid forms to be used as suspensions.
Reported are hereinbelow some examples of pharmaceutical compositions according to the present invention for illustrative but not limitative purposes:
EXAMPLE 1
Pearls
______________________________________Every pearl contains:______________________________________active principle 10 mgOP vegetal oil 18.5 mg______________________________________
EXAMPLE 2
Chewable dragees
______________________________________Every dragees contains:______________________________________active principle 20 mgO.P. precipitated silica 20 mgcocoa 11 mgO.P. cocoa butter 3.5 mgO.P. anhydrous glucose 12 mgO.P. lean milk powder 17.5 mgO.P. talc 4.5 mgO.P. starch 11 mgethylcellulose 0.8 mgsodium carboxymethylcellulose 0.3 mgO.P. glycerin 0.1 mgnatural dye (Betacarotene) 1 mcgO.P. liquid paraffin 5 mcgO.P. solid paraffin 30 mcgsaccharose O.P. q.s. to 0.8 g______________________________________
EXAMPLE 3
Soft Capsules
______________________________________Every capsule contains:active principle 100 mgexcipients:O.P. peanut oil 100 mgcapsule components:O.P. gelatin 52 mgO.P. glycerin 16 mgnatural dye (E12+) 0.1 mg______________________________________
EXAMPLE 4
Vials for injective use
______________________________________Every vial contain:______________________________________active principle 100 mgdiluent: olive oil q.s. to 1 mg.______________________________________
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Hydroxyamines N-acyl derivatives with benzochroman or 2,3-dihydrobenzofuran carboxy acids and relative pharmaceutical composition for the therapeutic treatment of those CNS, vascular, cardiovascular, dermatologic and ophthalmic pathologies wherein it is important to associate an inflammatory modulation effect to an antioxidant activity.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to decking or fencing systems, and more particularly to an improved anchor fastener and anchoring system for decks or fences.
BACKGROUND
[0002] In both new building constructions and renovation projects, there is an increasing demand in the residential, commercial and public building construction industries to provide private homes, businesses such as shops and restaurants, and public park facilities with deck structures. These structures typically comprise joists overlain with planks or floor boards and bound by a plurality of posts. Because of its natural beauty, comparatively low cost and abundant supply, wood has historically been the predominant material of choice in the construction of decks and similar structures, e.g., walkways, steps, and boat decks and piers. However, the lumber used in the construction of such structures requires considerable and costly maintenance to slow its inevitable deterioration caused by continual exposure to the sun, rain, snow and other natural elements. Moreover, wooden decks and related structures are subject to splintering which can be a hazard to individuals in bare feet. And, wooden structures are highly flammable.
[0003] The traditional manner of attaching wooden decking planks to underlying joists is by nailing or screwing through the plank into the joist below. This attachment method presents a number of disadvantages. For example, nail or screw heads exposed on the top surface of the decking planks are aesthetically unappealing and may also present tripping, scratching or splintering hazards. Further, the nails may be pried upwards away from the joists by flexing of the deck planks caused by repeated foot traffic. Additionally, the use of nails or screws necessarily creates holes the decking planks which may cause the wood to split, and which may accelerate deterioration of the plank caused by weather or insects. Further disadvantages include increased difficulty of cleaning and/or painting the decking planks.
[0004] Recently, decking systems using rigid plastics such as polyvinyl chloride (PVC), and plastic/fiber composites have become an increasingly popular alternative to wood in the construction of decks and similar structures. These decking systems have been designed with various securing mechanisms. According to some of these designs, the flooring planks are secured to fastener strips which in turn are secured to the joists. In others, the decking planks are secured directly to the joists via screws or similar fastening means.
[0005] U.S. patent application Ser. No. 10/365,870 to Bruchu et al. discloses a decking system formed of extruded thermoplastic wood fiber composite having hollow profile deck planks which interact with decking anchors to form a platform structure. The deck planks have anchor flanges which cooperate with the anchor structure. The anchor structure has a shape that conforms to the anchor flanges to hold the planks in place. The anchor structure includes a vertical aperture into which a fastener is inserted to fix the anchor in place. This decking system requires a fairly complex design for the cooperating planks and anchor.
[0006] U.S. Pat. No. 5,953,878 to Johnson discloses a decking system formed of extruded hollow polyvinyl or plastic planks having a plurality of slots on the side surfaces which overly the joists. The slots are engaged by mounting cleats which act to secure the planks to the joints and to each other. The cleats include a vertical slot through which a fastener is inserted to secure the cleat to the underlying frame. The cleat in slot arrangement allows for the different rates of thermal expansion and retraction of the plastic planks compared to the supporting wood frame.
[0007] U.S. Pat. No. 5,660,016 to Erwin et al. discloses an extruded plastic decking plank and attachment system having planks formed of a rigid foam core and a resilient outer plastic shell. The attachment system includes hold down blocks which have a shape that cooperates with clamping portions on the planks to secure the planks to a support structure. The hold down blocks are secured to the support structure by a fastener which is inserted vertically through a top of the block.
[0008] An improved low cost, easily installed decking structure and decking anchor is desired.
SUMMARY OF THE INVENTION
[0009] According to one exemplary embodiment, an anchor for installing a plank in a deck system includes a base portion, a plank-engaging portion and a fastener aperture. The plank-engaging portion has at least one protrusion. The fastener aperture has a longitudinal axis which is inclined from vertical and extends through the base portion and plank-engaging portion.
[0010] The anchors described herein may advantageously be used to secure planks to joists in decking systems. Unlike current decking systems having anchors with vertical fastener apertures, which require an installer to keep the anchor tight against the joist when installing the fastener, the angled aperture of the anchors described herein reduces or eliminates the need for a tight controlled positioning of the anchor.
[0011] According to another aspect, a decking system includes a plurality of anchors and a plurality of planks. The anchors include a base portion, a plank-engaging portion, and at least one fastener aperture. The plank-engaging portion includes at least one protrusion. The fastener apertures have a longitudinal axis disposed obliquely from a vertical plane and which extend through the base portion and plank-engaging portion. The planks include a side wall having an anchor-engaging groove for cooperating with a corresponding protrusion of a corresponding anchor.
[0012] According to a further aspect, a method of installing a deck system comprises providing a plank having an anchor-engaging groove, providing an anchor having a plank-engaging portion and a fastener aperture having a longitudinal axis which is disposed obliquely from a vertical plane, laying the plank on a decking joist, inserting the plank-engaging portion of the anchor into the anchor-engaging groove of the plank, and inserting a fastener through the fastener aperture and into the decking joist.
[0013] According to another aspect, a decking system includes a plurality of decking planks, a plurality of anchors and a plurality of fasteners. The decking planks are disposed over supporting joists. Each of the decking planks have a first and second curvilinear side edge portion. The anchors have first and second side surfaces capable of frictionally mating between the first and second curvilinear side edge portion of adjacent ones of the decking planks. The fasteners are disposed through the anchors at an oblique angle from vertical for joining the decking planks to the supporting joists.
[0014] According to another aspect, a decking anchor has a generally key-hole shaped cross-section and a planar bottom surface.
[0015] According to another aspect, a system for anchoring adjacent planar members to a base member includes a plurality of anchors, a plurality of planar members and at least one base member. The plurality of anchors have a base portion, a planar member-engaging portion having at least one protrusion, and at least one fastener aperture with a longitudinal axis disposed obliquely from a vertical plane and extending through the base portion and planar member-engaging portion. The plurality of planar members include a side wall having an anchor-engaging groove for cooperating with a corresponding protrusion of a corresponding anchor. The anchors are fastened into the base member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an end view of a partial decking system according to one exemplary embodiment.
[0017] FIG. 2 is a top view of a partial decking system.
[0018] FIG. 3A is an isometric view of an exemplary anchor.
[0019] FIG. 3B is an isometric view of another exemplary anchor.
[0020] FIG. 4 is a top isometric view of a decking plank of the decking system of FIG. 1 .
[0021] FIG. 5 is a top view of a partial decking system according to another exemplary embodiment.
[0022] FIG. 6 is an isometric view of a further exemplary anchor.
[0023] FIG. 7 is an isometric view of another exemplary anchor.
[0024] FIG. 8 is an isometric view of another exemplary anchor.
[0025] FIG. 9 is an isometric view of a partial decking system employing the anchor of FIG. 8 .
[0026] FIG. 10 is an elevational side view of a partial decking system employing another exemplary anchor.
[0027] FIG. 11 is a front view of an exemplary partial fencing system.
DETAILED DESCRIPTION
[0028] This description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.
[0029] Referring to FIGS. 1 and 2 , an exemplary embodiment of a partial decking system 100 is shown including a plurality of anchors 10 , a plurality of planks 30 , a plurality of joists 40 , and a plurality of fasteners 50 .
[0030] The anchors 10 , planks 30 and joists 40 of decking system 100 may be comprised of a variety of materials, including wood, metal, polymer, and composite materials. These articles may be cut, molded, drawn, injection-molded or extruded, for example. Preferably, the planks and anchors are comprised of a thermoplastic/fiber composite. The thermoplastics that can be used may include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyacrylic materials, polyester materials and other common thermoplastics. More preferably, the anchors, planks and/or joists are comprised of an extruded vinyl/wood composite such as that employed in BOARDWALK® Composite decking and railing systems sold by CertainTeed Corporation of Valley Forge, Pa. The consolidation of vinyl and wood fibers into composite reinforcement may be made in-situ during in-line extrusion of the final end product extrudate, or, alternatively, prepared as a tape or rod and incorporated into an off-line extrusion of final product. The commingled fibers may also be pultruded, followed by overlay extrusion of a capstock polymer using a separate extruder, all in-line. In this case, the capstock polymer would preferably cover only the outside surface of the plank, anchor and/or joist. The capstock may be applied by coating or painting as well as coextruding. The polymer or composite articles, or the capstock overlaying the articles, may further include pigments, thermal stabilizers, impact modifiers, ultra-violet (UV) radiation screening agents and other performance and/or aesthetic enhancing additives.
[0031] Referring to FIGS. 1-3B , the anchor 10 , 10 ′ comprises a base portion 12 , a plank-engaging portion 14 , at least one fastener aperture 16 , 16 ′ and side walls 26 . A bottom surface 18 of the base portion 12 lies on the joist 40 . As best shown in FIGS. 3A and 3B , the sides 24 of the plank-engaging portion 14 are preferably substantially semi-circular in shape, i.e., a cross-section of the plank-engaging portion 14 is circular or oval in shape. Side walls 26 of anchor 10 are substantially flat. The plank-engaging portion 14 includes two protrusions 20 a - b , each protrusion capable of engaging a corresponding anchor-engaging groove 38 on an adjacent plank 30 . The protrusions 20 a - b are preferably shaped to substantially conform to the anchor-engaging grooves 38 of the planks 30 . The top of each protrusion 20 a - b preferably includes a substantially planar section 22 a - b which serves as the entry point for the fastener aperture 16 , 16 ′. The planar section 22 a - b allows the head of the fastener 50 to lie flush with the planar section 22 a - b.
[0032] The anchor 10 can have a fastener aperture predrilled or premolded, or the fastener can form its own aperture when it is drilled or nailed, for example. The anchor 10 could also have one or more starter holes or notches for helping to start the fastener. The fastener aperture 16 , 16 ′ is preferably pre-pierced in the anchor 10 , 10 ′. It extends through the plank-engaging portion 14 and the base portion 12 at an oblique angle ø away from vertical. Preferably the angle ø is between about 5 and 60 degrees away from vertical. By placing the fastener aperture 16 , 16 ′ at an angle away from vertical, the bottom surface 18 of the anchor 10 , 10 ′ does not have to be held tight against the joist when installing the fastener as is typically the case with anchors having vertical fastener apertures.
[0033] The anchor may include one fastener aperture 16 , as shown in FIG. 3A , which begins at the planar section 22 a of protrusion 20 a , or alternatively may also include a first and second fastener aperture 16 ′, as shown in FIG. 3B , which begins at the planar section 22 b of protrusion 20 b . The fastener apertures 16 ′ may overlap in the anchor 10 ′ or may be non-overlapping. The inclusion of a second fastener aperture allows the anchor 10 ′ to be placed adjacent to the plank in either of two orientations to anchor the plank to the joist, resulting in a less labor-intensive installation.
[0034] Referring again to FIGS. 2 and 3 A-B, in decking system 100 , there is preferably a separate anchor 10 , 10 ′ on each joist 40 to anchor each plank 30 . Preferably, the anchor 10 , 10 ′ of decking system 100 has a width W 1 less than the width W 2 of the joist 40 .
[0035] Referring now to FIG. 7 , another embodiment of an anchor 15 is shown. Anchor 15 includes a plank-engaging portion 17 , a base portion 19 and at least one fastener aperture 21 a - b . Unlike anchors 10 , 10 ′ which have side walls 26 that are substantially flat, the entire plank-engaging portion 17 of anchor 15 is substantially spherical, spheroidal or ellipsoidal, and the base portion 19 has a bottom surface which is substantially circular (the anchor 15 resembles a doorknob). Preferably, a top of the plank-engaging portion 17 includes at least one, and preferably two, planar sections 23 a - b . The planar sections 23 a - b are preferably the entry point for the fastener apertures 21 a - b which extend through the plank-engaging portion 17 and base portion 19 at an oblique angle ø away from vertical. Preferably, the angle ø is between about 5 and 60 degrees away from vertical. Anchor 15 may have one fastener aperture, but preferably has two fastener apertures 21 a - b , which may be criss-crossed, overlapping or non-overlapping. The substantially spherical, spheroidal or ellipsoidal configuration of anchor 15 and presence of two fastener apertures allows an installer to place the anchor 15 in nearly any orientation against a plank and have a fastener aperture accessible for inserting a fastener.
[0036] Advantageously, anchors 10 , 10 ′, 15 are hidden or substantially hidden from view when installed in the decking system 100 . The anchors 10 , 10 ′, and 15 also allow installation of the fasteners 50 from the top of the deck as opposed to the bottom, and therefore makes it easier to build decks which are near ground level. Also, unlike some decking systems having hidden fasteners which require special fasteners, standard fasteners, such as nails or deck screws may be used in decking system 100 .
[0037] Referring to FIGS. 1 and 4 , the planks 30 of decking system 100 include a top surface 32 , a bottom surface 34 , and two side walls 36 a - b . Each sidewall 36 a - b includes an anchor-engaging groove 38 , which enables the planks 30 to be fastened to the joists 40 by means of the anchors 10 , 10 ′, 15 . Preferably the anchor-engaging groove 38 extends the length of the plank 30 as shown in FIG. 4 . Alternatively, each side wall 36 a - b may include a plurality of anchor-engaging grooves located intermittently along the length of the plank 30 at locations where the plank 30 is to be anchored to the joists 40 . Preferably, the anchor-engaging groove 38 has a shape which conforms to the protrusions 20 a - b of the anchor 10 , 10 ′, 15 . Where the planks are comprised of a metal or a polymer or composite material, the anchor-engaging groove 38 is preferably formed in the plank during manufacture of the plank by molding, drawing or extrusion, depending on the material. Where the planks are comprised of lumber, the anchor-engaging grooves may be formed by a hand tool or a groove-forming machine. The decking system 100 may include one or more end planks (not shown) having only one side wall with an anchor-engaging groove and the other side wall having a flat surface.
[0038] The planks 30 can be of any length or width, but preferably have a length and width equal to those of standard wood lumber. Where the planks are comprised of polymer or composite materials, the planks can be fabricated to include a simulated wood grain outer surface. Also, where the planks are comprised of polymer or composite materials, the planks may be substantially solid, partially solid, or hollow. Where the planks are hollow, they may include internal reinforcement braces. As stated above, the planks comprised of a polymer or composite material may include a capstock layer as an outer layer of the plank.
[0039] Referring now to FIGS. 5 and 6 , an alternative embodiment of a decking system 200 is shown including anchors 110 , planks 30 and joists 40 . The joists 40 and planks 30 are the same as described above with respect to decking system 100 , except that due to the nature of the anchor 110 , as described below, the planks of decking system 200 necessarily will contain an anchor-engaging groove which extends the length of the plank 30 .
[0040] The anchors 110 of decking system 200 comprise a base portion 112 , a plank-engaging portion 114 , and a plurality of fastener apertures 116 . Unlike anchors 10 , 10 ′, 15 , anchors 110 preferably extend substantially the length of the planks 30 . This configuration of the anchor advantageously provides extra support for the planks which is beneficial in demanding applications. (Alternatively, the anchors may have a length extending at least the distance between two joists.) A bottom surface 118 of the base portion 112 lies on the joist 40 . As best shown in FIG. 6 , the sides 124 of the plank-engaging portion 114 are preferably substantially semi-circular in shape. The plank-engaging portion 114 includes two protrusions 120 a - b , each protrusion engaging a corresponding anchor-engaging groove 38 on an adjacent plank 30 . The protrusions 120 a - b are preferably shaped to substantially conform to the anchor-engaging grooves 38 of the planks 30 . The top of each protrusion 120 a - b preferably includes a substantially planar section 122 a - b which serves as the entry point for the fastener aperture 116 . The planar section 122 a - b allows the head of the fastener 50 to lie flush with the planar section 122 a - b .
[0041] The fastener apertures 116 are preferably pre-pierced in the anchor 110 . They are preferably spaced intermittently along the length of the anchor 110 at locations where the anchor will intersect a joist 40 . The fastener apertures 116 extend through the plank-engaging portion 114 and the base portion 112 at an angle ø away from vertical. Preferably the angle ø is between about five and sixty degrees away from vertical. As stated above, by placing the fastener aperture 116 at an angle away from vertical, the bottom surface 118 of the anchor 110 does not have to be held tight against the joist when installing the fastener, as is typically the case with anchors having vertical fastener apertures.
[0042] The anchor 110 may include a plurality of fastener apertures 116 having an entry point along only one protrusion as shown in FIG. 6 , which begins at the planar section 122 a of protrusion 120 a , or alternatively, the anchors 110 may include a second set of fastener apertures (not shown) which begin at the planar section 122 b of protrusion 120 b . The fastener apertures may overlap in the anchor 110 or may be non-overlapping.
[0043] As with anchors 10 , 10 ′, 15 , anchor 110 is capable of being hidden or substantially hidden from view when installed in the decking system 200 .
[0044] Referring to FIGS. 8-9 , another embodiment of an anchor 310 and partial decking system 300 is shown. Anchor 310 includes a plank-engaging portion 314 , a base portion 312 and at least one fastener aperture 321 . The base portion 312 includes at least one end, and preferably two ends 316 , 318 , which terminate inwardly from the respective ends 320 , 322 of the plank-engaging portion 314 a distance sufficient to allow the respective end of the plank-engaging portion to engage and secure an adjacent plank 30 . A top of the plank-engaging portion 314 includes at least one, and preferably two, planar sections 323 a - b . The planar sections 323 a - b are preferably the entry point for the fastener aperture 321 (or apertures) which extend through the plank-engaging portion 314 and base portion 312 at an oblique angle away from vertical. (The exit point for apertures may be completely enclosed by a bottom surface of the base portion as shown in FIGS. 3A and 3B or may extend at least partially through a side of the base portion as described below and shown in FIG. 10 .) Preferably, the angle of the apertures 321 is between about 5 and 60 degrees away from vertical. Anchor 310 may have one fastener aperture 321 (as shown), but preferably has two fastener apertures, which may be criss-crossed, overlapping or non-overlapping.
[0045] This anchor embodiment allows the single anchor 310 to be used to secure two planks that are perpendicular to one another, and therefore would be beneficial for employment in picture-framing deck planks (see FIG. 10 ). The inclusion of two terminated base portion ends 316 , 318 of anchor 310 and the presence of two fastener apertures 321 allows an installer to place the anchor 310 in either of two orientations against a plank while having a fastener aperture accessible for inserting a fastener and also an end capable of securing a perpendicular plank. The anchor 15 shown in FIG. 7 may also be used in the decking system 300 to secure perpendicular decking planks.
[0046] Referring to FIG. 10 , another embodiment of an anchor 410 and decking system 400 is shown. Anchor 410 may have a size and shape similar to any of the anchors described herein, with the difference being that the exit point of the fastener aperture 412 is not entirely through the bottom surface 414 of the base portion 416 of anchor 410 , but rather extends at least partially through a side 418 of the base portion 416 . The purpose for this angle variation is to allow the fastener 50 to penetrate and directly secure the plank 30 to a joist. This embodiment may prevent the plank from moving due to expansion and contraction of the plank-forming material. Preferably, the fastener aperture 412 is at approximately between a 35-45° angle α away from vertical, and more preferably at approximately a 40° angle away from vertical. However, depending on the shape and width of the protrusions 420 a ,- b of the anchor 410 , and also the distance of any gap between the protrusions and the anchor-engaging groove 38 of the plank 30 , the angle from vertical may vary to ensure that the fastener connects with a portion of the plank 30 when inserted through the fastener aperture 412 .
[0047] Referring to FIGS. 1, 2 and 5 , the decking systems 100 , 200 , 400 are installed by placing planks 30 perpendicularly across a plurality of spaced-apart joists 40 . To anchor the planks 30 , a bottom surface 18 , 118 , 414 of the base portion 12 , 112 , 416 of anchors 10 , 10 ′, 15 , 110 , 410 are placed on joists 40 (in the embodiment shown in FIG. 2 , preferably anchors 10 are placed on each joist 40 ) and a protrusion 20 a , 120 a , 420 a of the anchors 10 , 10 ′, 15 , 110 , 410 is placed adjacent the anchor-engaging groove 38 of the plank 30 so that the fastener aperture 16 , 16 ′, 116 , 412 of the anchor is accessible by an installer. A fastener 50 (or fasteners for anchor 110 ) is then inserted into the anchor 10 , 10 ′, 15 , 110 , 410 via the fastener aperture 16 , 16 ′, 116 , 412 at an angle away from vertical as dictated by the angle of the fastener aperture. Tightening of the fastener 50 into the joist 40 will pull the anchor snugly into an anchoring position, preferably in firm contact with the anchor engaging groove 38 of the plank 30 . Referring to FIGS. 2 and 4 , anchoring of one side wall 36 b of the plank 30 may also push the plank into firmer engagement with a second set of anchors which have already been installed on an opposite edge 36 a of the plank 30 and which have been seated into the anchor engaging groove 38 on the opposite edge 36 a . Once the anchors for one side wall 36 a of a plank 30 have been fastened to the joist 40 , the anchor-engaging groove 38 of another plank 30 is placed against the protrusion 20 b , 120 b , 420 b of the anchor 10 , 10 ′, 15 , 110 housing the entry point for the fastener aperture 16 , 16 ′, 116 , 412 (or is placed in sufficient enough proximity to the anchor-engaging groove 38 to facilitate anchoring of the plank 30 ). Depending on the desired appearance and the size and form of the anchor 10 , 10 ′, 15 , 110 the anchors may be entirely hidden from view, or a gap 60 of a desired width (preferably from 0-0.5 inch, and more preferably . 125 inch) may be left between the planks 30 .
[0048] Although advantageously employed in decking systems, the anchors and planks described herein may also be beneficially employed in fencing systems to form a fence with a hidden fastening system. Such a system may eliminate unappealing visible nail or screw holes. Referring to FIG. 11 , a partial fence 500 is shown including at least one rail 510 , a plurality of panels 520 and a plurality of anchors 530 . The anchors 530 may be any anchor described herein with respect to a decking system. The anchors are fastened to the rails 510 to secure adjacent panels 520 to the rails 510 .
[0049] Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.
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An anchor for installing a plank in a deck system includes a base portion, a plank-engaging portion and a fastener aperture. The plank-engaging portion has at least one protrusion. The fastener aperture has a longitudinal axis disposed at an oblique angle from vertical and extends through the base portion and plank-engaging portion. According to another aspect, a decking anchor has a generally key-hole shaped cross-section and a planar bottom surface.
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FIELD OF THE INVENTION
[0001] The invention relates to treatments of subterranean formations to control water production and inhibit scale formation, and most particularly relates, in one non-limiting embodiment, to methods and compositions for controlling water production and inhibiting scale occurrence together in subterranean formations with a minimum number of steps.
BACKGROUND OF THE INVENTION
[0002] Water production is one of the major problems that occur in oil producer wells, which are at their most profitable when they are producing only oil. Produced water is an inevitable consequence of water injection when waterflooding is used to develop an oil reservoir or when the field drive mechanism involves strong aquifer support. Various problems are associated with the production of water including (a) the “lifting” (pumping) of the water itself from downhole to the surface, (b) the corrosion that may occur in downhole completions, tubulars, valves and surface equipment due to the corrosivity of the produced brine, (c) in some cases, mineral scale deposition due to the presence of precipitating minerals in the produced water (commonly calcite—calcium carbonate and barite—barium sulphate etc.), (d) the possible formation of gas hydrates (water/gas “ice”) at low temperatures in sub-sea lines, and (e) the treating of the water to remove any environmentally unfriendly substances (such as low levels of hydrocarbons) before disposal, etc. All of these problems result in expenditure of time, money and other resources and hence, are detrimental to the profitability of an oil production operation.
[0003] A chemical treatment that would reduce water production while preserving the flow of oil in an oil production well is known as a “water control” treatment (WCT). Many patents exist based on polymeric materials and their cross-linked gels, and also on other materials, describing how to perform such treatments. Likewise, certain downhole chemical treatments to inhibit the formation of mineral scale using chemical scale inhibitors are also well known and are referred to as “scale inhibitor ‘squeeze’ treatments” (SISTs). Again, many scale inhibitor chemicals and application processes are described in the scientific and patent literature.
[0004] As will be discussed in further detail, water control treatments and scale inhibitor treatments of subterranean formations involve a number of steps to achieve effective results. As will also be further explained, scale formation is partly a function of water production. Thus, it would be desirable if methods or techniques could be found which would combine these treatments so that the total number of steps could be minimized, yet achieve comparable results.
SUMMARY OF THE INVENTION
[0005] An object of the invention is to provide methods and techniques for controlling water production and scale formation in a subterranean formation in the same operation.
[0006] Another object of the invention is to provide combined methods and techniques for controlling water production and scale formation in a subterranean formation that may employ conventional chemistries.
[0007] Yet another object of the invention is to provide combined methods and techniques for controlling water production and scale formation in a subterranean formation that may employ conventional equipment and steps combined in a novel way.
[0008] In carrying out these and other objects of the invention, there is provided, in one form, a method for inhibiting the formation of scale and the production of water in a well in a subterranean formation having a water production zone or zones, which involves first shutting in the well. A water control treatment is injected into the water production zone. A scale inhibitor is squeezed into the water production zone before, during or after the water control treatment. Next, the well is soaked in for a period of time. Finally, the well is back produced. In one non-limiting embodiment of the invention, the injection of the water control treatment is the next stage after squeezing the scale inhibitor into the water production zone, in the absence of an intervening step or stage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIGS. 1 ( a ) through 1 ( d ) are schematic, cross-sectional illustrations of the types of water control problems arising in producer wells, FIGS. 1 ( a ) and 1 ( c ), and the two types of Water Control Treatment (WCT), a conventional zone blocking water shut-off treatment (WSOT), FIG. 1( b ), and relative permeability modifier treatment (RPMT) FIG. 1( d );
[0010] FIGS. 2 ( a ) through 2 ( f ) are schematic, cross-sectional illustrations of the major steps in a conventional scale inhibitor squeeze treatment (SIST);
[0011] FIGS. 3 ( a ) through 3 ( e ) are schematic, cross-sectional illustrations of the major steps in one embodiment of the combined water control-scale inhibitor treatment of the present invention, where the water control features resemble a water shut-off treatment (WSOT);
[0012] FIGS. 4 ( a ) through 4 ( e ) are schematic, cross-sectional illustrations of the major steps in one embodiment of the combined water control-scale inhibitor treatment of the present invention, where the water control features resemble a relative permeability modifier treatment (RPMT); and
[0013] [0013]FIG. 5 is a graph of predicted scale inhibitor squeeze returns as a function of time from a model field case for a base case SIST and a combined RPMT-SIST as calculated by a near wellbore scale inhibitor squeeze treatment design simulation model (SQUEEZE V).
DETAILED DESCRIPTION OF THE INVENTION
[0014] It has been discovered that water control treatments and scale inhibitor treatments can be combined to simultaneously control scale and inhibit water production in a subterranean formation using fewer total steps than the sum of steps used in those treatments conventionally practiced separately. These combined treatments provide savings of cost, time and resources in improving the production of hydrocarbons from a subterranean formation.
[0015] Water Control Treatments (WCT)
[0016] Chemical applications have been described whereby a material (usually, but not exclusively, a polymer or a cross-linked polymer) is injected into a reservoir formation 10 , typically 5-15 ft (1.5-4.5 m) radial penetration, with the purpose of reducing water production (see FIG. 1). Such materials 20 may operate through the following mechanisms.
[0017] (i) The first mechanism involves blocking all of the flow in a completely water-producing zone or stratum 12 of the reservoir 10 . Such a water shut-off material 20 would normally be a strong cross-linked polymer gel and these are often referred to as “blocking gels”. Schematic illustrations of how such gels operate are shown in FIGS. 1 ( a ) and 1 ( b ), where the water producing zone 12 of subterranean formation 10 is isolated with packers 18 before the treatment is applied. Chemical packages of this type and their field application methodology are referred to as water shut-off treatments (WSOTs). Suitable water shut-off materials 20 include, but are not necessarily limited to, cross-linked polysaccharides, polyacrylamides—sometimes in their hydrolysed form (HPAM)—as well as non-ionic and cationic forms of polyacrylamide; silica gels, resins, cement and other materials. Crosslinkers used to gel the polymers include, but are not necessarily limited to, aluminum (III), chromium (III), boron, several other metal ions and also many organic materials such as glyoxal.
[0018] (ii) The second mechanism includes selectively reducing the flow of water while allowing the oil to flow freely—or with minimal reduction in its flow. A material 22 used in such an operation would normally be a polymer or a polymer with a low level of cross-linking and is often referred to as a “relative permeability modifier” or as a “disproportionate permeability reducer” 22 ; below, such applications are denoted as relative permeability modifier treatments (RPMTs). These types of treatment are generally applied to all areas of the near wellbore 16 without any isolation (i.e. they are “bullheaded”). A schematic of how RPMTs are applied is shown in FIGS. 1 ( c ) and 1 ( d ). Suitable relative permeability modifier materials 20 include, but are not necessarily limited to, cross-linked polysaccharides, polyacrylamides in their hydrolysed, non ionic or cationic forms (as described above for WSOTs), applied as either polymer only or “weak gel” treatments; or other materials. Within the context of this invention, by “polymer only” refers to a polymer without any crosslinker, i.e. a non-crosslinked polymer. Also within the context of this invention, the term “weak gel” is defined as a gel that is still flowable or which may be poured in bulk volumes, as contrasted with relatively stronger gels used in WSOTs that will completely block the subterranean rock to all flow, and/or which will not flow. Suitable crosslinkers include those described above for WSOTs, although it will be understood that the polymers used in RPMTs may not be as highly crosslinked as the polymers used for WSOTs.
[0019] As noted above, examples of both of the above types of water control treatment have been proposed and described in the general scientific and patent literature.
[0020] Scale Inhibitor Squeeze Treatments (SISTs)
[0021] Many problems arise because of the production of water as noted above. One specific and important one is the deposition of mineral scale, which does not occur invariably but depends on the ionic composition of the produced brine in a manner that is generally quite well understood in terms of the solution chemistry. The severity of this problem in terms of how much scale is deposited under given conditions (of temperature and pressure) is also relatively well understood and depends on the composition of the produced brine, as well as other fluids and materials the produced brine comes into contact with. The most common mineral scales that occur in oil production operations are calcite (calcium carbonate, CaCO 3 ) and barite (barium sulphate, BaSO 4 ). Calcite forms when formation brines, at high pressure, containing high levels of calcium (Ca 2+ ) and bicarbonate (HCO 3 − ) ions, are brought to the surface and the pressure reduces (or the reservoir pressure is lowered by production). At the lower pressure, insoluble calcite precipitates and carbon dioxide (CO 2 ) is released into the gas phase. Barite, on the other hand, is formed when incompatible brines mix and this usually occurs when barium rich formation brine mixes with sulphate rich injected sea water, a process that can occur in the vicinity of or in the producer wellbore.
[0022] To prevent scale formation in water producing wells, scale inhibitor “squeeze” treatments (SISTs) are quite routinely applied in petroleum reservoirs using various chemical scale inhibitors. Suitable scale inhibitors include, but are not necessarily limited to, phosphonates, (e.g. diethylenetriamine penta(methylene) phosphonic acid, DETPMP), polyphosphino-carboxylic acids (PPCAs) and polymers such as poly acrylate (PAA) and poly vinyl sulphonate (PVS), sulphonated polyacrylates (VS-Co), phosphonomethylated polyamines (PMPA) and combinations thereof.
[0023] A “squeeze” treatment, which is shown schematically in FIG. 2, is one where the scale inhibitor solution (generally but not invariably in aqueous solution) 30 is injected down the producing well 32 into the reservoir formation 10 and allowed to interact with the rock matrix and then the well is put back on production. As the produced brine flows past the treated rock formation 10 some of the scale inhibitor 30 desorbs or dissolves (depending on the inhibitor-rock interaction mechanism—see below) into the produced brine. Hence, the produced brine contains a low level of scale inhibitor (from <1 ppm to tens or hundreds of ppm). This low—often substoichiometric—level of scale inhibitor 30 is often enough to prevent the scale deposition from occurring.
[0024] At the heart of the mechanism of how such “squeeze” treatments work is the type of inhibitor-rock interaction referred to above which can be described by (i) an adsorption mechanism (Ad), (ii) a precipitation reaction (Pt) or, in the general case, (iii) a combined adsorption-precipitation reaction (Ad-Pt). The field application of scale inhibitors operating through each type of mechanism ((i)-(iii)) is denoted as SIST-Ad, SIST-Pt and SIST-Ad-Pt, respectively. The subsequent release of the inhibitor in SIST-Ad, SIST-Pt and SIST-Ad-Pt treatments is hence by a desorption, a dissolution or a combined desorption/dissolution mechanism, respectively.
[0025] The scale inhibitor squeeze treatment (SIST) may involve several steps in its actual application although the actual steps, the details of pump rates, the fluid volumes, the inhibitor types and concentrations involved may vary to some degree from one application to another. In general, a typical SIST involves the following stages as shown in FIG. 2:
[0026] 1. Shut-in the producing well 32 (FIG. 2( a ));
[0027] 2. Inject a pre-flush or “spearhead” fluid 34 that is usually an aqueous solution of surfactant (demulsifier) and a low concentration of scale inhibitor (tens to hundreds ppm) (FIG. 2( b )) into the water producing zone 12 ;
[0028] 3. Inject the main scale inhibitor 30 slug—typically on the order of tens to hundreds bbl (about 1-150 m 3 ) of scale inhibitor—in solution (usually aqueous brine) at concentrations of thousands of ppm to a few % (e.g. 1-10% as supplied) (FIG. 2( c ));
[0029] 4. Injection of a brine “overflush” 36 in order to “push” the inhibitor 30 slug deeper into the formation 12 away from the immediate vicinity of the wellbore 16 . Typically, tens to hundreds bbl (about 1-150 m 3 ) of overflush 36 are injected in order to push the main chemical inhibitor slug from approximately 5 ft to 25 ft (about 1.5-7.6 m) away from the wellbore (FIG. 2( d ));
[0030] 5. Shut-in the well 32 for a “soak” period in order to allow the interaction between the inhibitor 30 and rock matrix to occur—typically from 4 hours to 24 hours (FIG. 2( e ));
[0031] 6. Put the well 32 back on production allowing the flows of oil (and water) to re-establish. The well 32 may not produce its full pre-treatment volumetric flow rate immediately i.e. it may require a “clean up” time (FIG. 2( f ).
[0032] Note that even although the SIST involves several steps, for clarity and simplicity hereinafter the SIST is referred to as if it were a single treatment.
[0033] Over time, the level of inhibitor 30 in the produced water after a scale inhibitor squeeze will gradually drop below an acceptable threshold level (referred to as the MIC=Minimum Inhibitor Concentration) for the further prevention of scale formation. Below this MIC level, scale may now form almost as readily as before and another “squeeze” treatment is required. The time between such squeeze treatments defines the “squeeze lifetime”. It has also been discovered that the squeeze lifetime is longer the lower the cumulative volume of water that is produced, i.e. a scale inhibitor squeeze treatment in a well producing 100 barrels (about 16 m 3 ) of water per day (bbl/D) will generally last longer in time than a similar treatment in the same well producing 1000 bbl/D (about 160 m 3 /D) although the cumulative volume of treated produced brine may be broadly similar. Despite this latter fact, it is highly desirable to extend squeeze lifetime as long as possible.
[0034] Inventive Combined Water Control and Scale Inhibitor Squeeze Treatments
[0035] Benefits: From the above discussion, it follows that if a method can be discovered to reduce the quantity of produced brine in a given well, then such a method would have a number of generally recognised benefits per se. Specifically, one of these benefits would be that less scale would form due to the lower production of brine. As a consequence, where there is lower brine production, a scale inhibitor squeeze treatment will generally last longer, i.e. it will, other things being equal, extend the scale inhibition squeeze lifetime in actual time.
[0036] Other benefits of having a chemical treatment which combines the functions of controlling (i.e. reducing) water production while carrying out a scale inhibitor squeeze treatment become clear. Treating a producer well is an intrinsically loss-making activity since it involves stopping and shutting in a well that is producing oil—but to prevent scale formation, this is required. However, it has been discovered that for a single entry into the well, two treatments—each of which is beneficial and/or necessary—can be carried out viz. a combined water control scale inhibitor squeeze. This combined treatment has benefits per se as well as extending the effective squeeze lifetime in the well, hence reducing the number of well interventions that are required.
[0037] Mechanics of combined treatments: Since there are different ways in which water control is applied (WSOTs or RPMT) and there are also differences in the mechanism of how scale inhibitors work (SIST-Ad, SIST-Pt, SIST-Ad-Pt), the details of the combined treatments tend to be somewhat different. However, all possible combinations—that is either (WSOT or RPMT) with any of (SIST-Ad, SIST-Pt, SIST-Ad-Pt), are encompassed by this invention and are discussed in turn below. There are in fact two main variants on the combined treatment governed by the nature of the water control method i.e. by WSOT or RPMT. Hence, these two cases will be described separately.
[0038] WSOT-SIST Combined treatments: First, how a SIST is combined with a treatment to fully block a water producing zone 12 will be outlined i.e. a WSOT (please note that several such zones may exist in a single well 32 ). The various stages for this type of treatment are shown schematically in FIG. 3. Firstly, in FIG. 3( a ) the nature of the type of problem where a WSOT might be applied is one where there are a single (or several separate) reservoir zone (or zones) 12 producing water and other zones producing (mainly) oil 14 . Thus, the objective is to block all of the water coming from this water zone 12 (or from each of these water zones 12 ) and hence complete fluid shut-off in such zones 12 is required. In WSOTs, one does not want to affect the oil flow in the (mainly) oil producing layers 14 (see FIG. 3( a )). In the schematic treatment descriptions below, the SIST or WSOT is referred to as a single stage treatment although in practice each may involve several steps with different fluid injection in each step, as described for the SIST above.
[0039] The stages in a combined WSOT-SIST are as follows.
[0040] Stage 1 (FIG. 3( b )): Shut-in the producing well.
[0041] Stage 2 (FIG. 3( c )): First inject the SIST 40 into the producer well 32 either with or without selective placement technology (e.g. packers 18 ) in the well in order to place the SIST 40 in the water producing zone 12 , as shown. Note that selective placement of the scale inhibitor or SIST 40 is optional in this stage.
[0042] Stage 2(a) (not shown): An optional brine overflush may be performed at this stage if it is appropriate for the specific placement of the SIST 40 (see FIG. 2( d )).
[0043] Stage 3 (FIG. 3( d )): Inject the WSOT 20 into the producer well 32 either with or without selective placement technology in the well 32 in order to place the scale inhibitor 40 in the water producing zone 12 , as shown. Note that selective placement of the water control chemical 20 is strongly recommended for this stage and is of more importance in the correct placement of the WSOT 20 than for the SIST 40 . In addition, the chemical slug used in the WSOT 20 may also contain a level of scale inhibitor 30 with a concentration on the order of tens to hundreds of ppm to afford additional scale protection (the combination designated as 42 ).
[0044] Stage 3(a) (not shown): An optional brine overflush may be performed at this stage if it is appropriate for the specific placement of the WSOT (and the previous SIST).
[0045] Stage 4 (FIG. 3( e )): Following a suitable “soak” period, the producer well 32 is put back on normal production. There may be some “clean up” time needed for the well and, indeed, if the WSOT has worked correctly, it should not return to the full volumetric fluid production rate at the same pressure drawdown. However, the water production rate should be lower and the fractional flow of oil should be higher. In addition, the produced water should now contain an appropriate concentration of scale inhibitor and the effective squeeze lifetime should be longer as a consequence of the reduced water production.
[0046] RPMT-SIST Combined treatments: Next will be outlined how a SIST is combined with a treatment to disproportionately change the water and oil flows in the same producing zone or zones, i.e. a RPMT (commonly several such zones may exist in a single well). The various stages for this type of treatment are shown schematically in FIG. 4. Firstly, in FIG. 4( a ) it is noted that the nature of the type of problem where a RPMT might be applied is where there are a several reservoir zones co-producing water and oil. Thus, an objective is to reduce the water flow and to maintain the flow of oil (although some small reduction in the oil flow rate may be acceptable). For the same pressure gradient, the fractional flow of oil will be increased by a successful RPMT. In the schematic treatment descriptions below, each of the SIST or RPMT is referred to as a single stage treatment although in practice each may involve several steps with different fluid injection at each step as described for the SIST above.
[0047] The stages in a RPMT-SIST are as follows.
[0048] Stage 1 (FIG. 4( b )): Shut-in the producing well 32 .
[0049] Stage 2 (FIG. 4( c )): First, inject the SIST 40 into the producer well 32 either with or without selective placement technology in the well in order to place the scale inhibitor 40 in the water producing zone 12 , as shown. Note that selective placement of the scale inhibitor is optional in this stage and one would normally inject this as a “bullhead” treatment (i.e. without placement technology) as is illustrated in FIG. 4( c ).
[0050] Stage 2(a) (not shown): An optional brine overflush may be performed at this stage if it is appropriate for the specific placement of the SIST 40 (again, please see FIG. 2( d )).
[0051] Stage 3 (FIG. 4( d )): Inject the RPMT 44 into the producer well 32 either with or without selective placement technology in the well in order to place the scale inhibitor in the water/oil producing zones, as shown. Note that selective placement of the RPMT 44 is optional in this stage and one would normally inject this as a “bullhead” treatment (i.e. without placement technology) as is illustrated in FIG. 4( d ). In addition, the chemical slug used in the RPMT 44 may also contain a level of scale inhibitor with a concentration on the order of tens to hundreds of ppm to afford additional scale protection.
[0052] Stage 3(a) (not shown): An optional brine overflush may be performed at this stage if it is appropriate for the specific placement of the RPMT 44 (and the previous SIST) 40 (again, please see FIG. 2( d )).
[0053] Stage 4 (FIG. 4( e )): Following a suitable “soak” period, the producer well 32 is put back on normal production. There may be some “clean up” time necessary for the well and, indeed, if the RPMT 44 has worked correctly, it should not return to the full volumetric fluid production rate at the same pressure drawdown. However, the water production rate should be lower and the fractional flow of oil should be higher. In addition, the produced water should now contain an appropriate concentration of scale inhibitor and the effective squeeze lifetime should be longer as a consequence of the reduced water production.
[0054] Technical and Application Notes
[0055] A number of technical matters involving the basic science of these combined treatments along with their field application have been considered and are encompassed by this invention, including, but not necessarily limited to the following.
[0056] (1) WSOT and RPMT Materials: Many materials—usually but not exclusively of a polymeric nature—have been used for both water shut off and relative permeability modifier treatments (WSOTs and RPMTs). Examples of such polymeric materials include, but are not necessarily limited to, polyacrylamides (PAM)—sometimes in their hydrolysed form (HPAM)—as well as non-ionic and cationic forms of polyacrylamide, silica gels, resins, cements, etc. Crosslinkers used to gel the polymers include, but are not necessarily limited to, aluminum (III), chromium (III), boron, several other metal ions and also many organic materials such as glyoxal. Within the context of this description, all of these treatments and all combined treatments herein refer to all such water control materials, unless otherwise noted.
[0057] (2) SIST Materials: Many materials—usually but not exclusively phosphonates and polymeric species—have been used for scale inhibitor squeeze applications (SISTs). Examples of scale inhibitors include, but are not necessarily limited to, phosphonates such as DETPMP, polyphosphino-carboxylic acids (PPCA) and polymers such as poly acrylate (PAA), poly vinyl sulphonate (PVS), sulphonated poly acrylates (VS-Co), phosphomethylated polyamines (PMPA) etc. Within this description, references to scale inhibitor materials and/or combined treatments include all such scale control materials, unless otherwise noted.
[0058] (3) Horizontal well applications—diverters: Although the illustrative examples shown and described herein have been applied to schematics of vertical wells, the combined water control-scale inhibitor squeeze treatments may also be applied with some process design modifications in horizontal wells. In some cases, it may be desirable to use diverter fluids for the correct placement of the water control and SIST slugs and the methods of this invention are expected to be applicable for such applications.
[0059] (4) Treatment design: Software has been developed to model and hence design such well treatments.
[0060] (5) Competitive adsorption: In the case of RPMs, they are known to involve a surface adsorption mechanism in order to cause a differential change in the water and oil flows—as, indeed, may the scale inhibitor. In the combined treatment, some proportion of the rock adsorption sites may be occupied by scale inhibitor thus reduce the effect of the polymeric adsorption for the RPM. However, it is likely that the much smaller scale inhibitor molecules will be selectively displaced by the strongly adsorbing polymer although this effect may take some hours for which a shut-in will be necessary.
[0061] Sequence: In the case of a RPMT, the SIST may be injected before, after or together with the RPMT injection. In the case of the WSOT, injection of the SIST with the WSOT is not desirable, since no water will flow through the gel that is formed. Bullhead injection after the WSOT is less effective than before as the scale inhibitor in the blocked zone will not be able to protect the well against scale formation. The oil producing zones, however will be protected from water that diverts around the blocking gel.
[0062] Verification Using a Near Wellbore Scale Inhibitor Squeeze Treatment Design Simulation Model (SQUEEZE V)
[0063] The proof of concept of this invention has been carried out using predictive modeling using a software model, SQUEEZE V. The scale inhibitor squeeze treatment (SIST) is calculated for a 5 layer near wellbore field case before and after a conceptual water control treatment has been carried out. The main details and design parameters are as follows:
[0064] (a) A 5-layer near wellbore r/z-grid simulation model is constructed with layer permeabilities: k 1 =150 mD (top), k 2 =150 mD, k 3 =300 mD, k 4 =100 mD, k 5 =100 mD (bottom).
[0065] (b) Each layer is 15 ft (4.6 m) thick and has porosity, φ=0.17.
[0066] (c) The scale inhibitor treatment volume of 1059.7 bbl (168.5 m 3 ) of concentration 130,000 ppm inhibitor was pumped at a rate of 3.7103 bbl/min. (0.59 m 3 /min.) into the formation followed by an overflush of 1816.7 bbl (288.8 m 3 ) of brine pumped at 3.9063 bbl/min. (0.62 m 3 /min.).
[0067] (d) The scale inhibitor adsorption isotherm, Γ(C), is described by a Freundlich function of the form, Γ(C)=α.C β where α=489.2 and β=0.35 (C in ppm) and non-equilibrium adsorption is assumed;
[0068] (e) The modeled water control treatment is of RPMT type and the water reduction varies from layer to layer in the model, but is in the approximate range 20-25%.
[0069] (f) A straightforward SIST of (non-equilibrium) adsorption type is modeled with a set of base case water flows from the 5 layers based on the local permeabilities of the layers. A combined RPMT-SIST is then modeled with the above assumptions of water flow reduction.
[0070] (g) The predicted scale inhibitor returns are shown for this case for the SIST and the combined RPMT-SIST in FIG. 5.
[0071] As shown in FIG. 5, the combined treatment shows a significant improvement in the scale inhibitor performance for the very modest levels of water control using a RPMT. At an assumed of MIC=5 ppm, an increase in squeeze lifetime of approximately 30% is predicted.
[0072] The process design and chemical materials that can be used therein are described for the inventive combined water control and scale inhibitor squeeze treatment. Two types of combined applications are explicitly identified as follows:
[0073] (i) WSOT-SIST: which is more appropriate when certain reservoir layers produce entirely water and other layers produce (mainly) oil; and
[0074] (ii) RPMT-SIST: which is more appropriate when several reservoir layers co-produce both water and oil.
[0075] The concept has been verified using predictions from the simulation model, SQUEEZE V that show that a relatively modest level of water control can lead to significant improvement in the scale inhibitor returns.
[0076] It is expected that all chemical systems which have previously been identified for use in the separate treatments (water control and scale inhibitions) can likewise be used for such combined treatments.
[0077] Many modifications may be made in the methods of this invention without departing from the spirit and scope thereof that are defined only in the appended claims. For example, the exact scale inhibitors and/or polymer gels or other relative permeability modifiers may be different from those used here. Various combinations of stages or steps of the water control and/or scale inhibitor squeeze treatments other than those exemplified or explicitly described here are also expected to find use in providing an improved combined method. Further, different operating parameters from those discussed and exemplified are also expected to be useful herein.
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A combined scale inhibitor treatment and water control treatment is described that requires fewer steps than the sum of each treatment procedure practiced separately. The control of water production simultaneously further reduces the amount of scale formed. Conventional water control chemicals and scale inhibitors of a wide variety of types can still be employed to advantage, and the same equipment may be used as employed for the treatments implemented separately.
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FIELD OF THE INVENTION
[0001] The present invention relates to a wheel hub bearing unit for a vehicle, said hub bearing unit comprising a rotating bearing ring and a non-rotating bearing ring, where the rotating bearing ring has at least a radially extending wheel mounting flange with a reference flange surface.
BACKGROUND TO THE INVENTION
[0002] In a typical wheel end assembly, a brake rotor may be fitted to the mounting flange of the rotating bearing ring of the hub unit. The wheel rim is then mounted against the brake rotor and both are bolted to the wheel mounting flange. The hub-rotor interface is exposed to atmospheric corrosion from humid air and from salt water. The corrosion leads to the formation of rust on and between the contacting surfaces of the wheel mounting flange, brake rotor and wheel rim. The layer of corrosion that forms on the wheel mounting flange surface results in increased runout, which may exceed that specified for finished and assembled hub units of e.g. 10 to 15 micro meters. When vehicles are serviced and undergo replacement of a brake rotor, the fixation of a (new) brake rotor on a wheel mounting flange having corrosion on the contact surface for the brake rotor would lead to axial runout and brake shudder.
[0003] US 2006/0177169 A1 discloses a hub unit with a wheel mounting flange for mounting a wheel on the hub. The flange is provided with a rust-preventive layer on the surface receiving the wheel. This rust-preventive layer may be a fused ceramics material or a plastic material either moulded onto the surface by insert moulding or a separate part fixed to the surface by an adhesive.
[0004] EP 0 800 011 A2 discloses a corrosion-protective element for protecting junctions between metal components made of different metals against electrolytic corrosion when exposed to moisture by providing a shield of sheet metal which is electrically passivated or has an anti-corrosion coating on its opposite surfaces.
[0005] It is further known to provide electrolytic zinc plating on the hub flange surface to prevent corrosion. The electrolytic plating is usually a bath process where at least the component in which the flange is formed is submerged in molten zinc and subjected to high temperature (over 150° C.) baking to eliminate hydrogen embrittlement.
SUMMARY OF THE INVENTION
[0006] By the invention, corrosion protection of the surface of the wheel mounting flange of a hub bearing unit is realized in a cost-effective manner by providing a hub bearing unit, wherein a gasket with at least a sacrificial metal gasket surface is provided on the flange surface. The sacrificial gasket comprises a radially oriented disc portion. Moreover, the gasket is adapted for attachment on the reference flange surface, before the mounting of a brake rotor or wheel against the wheel mounting flange.
[0007] According to the invention, corrosion protection of the wheel mounting flange of a hub bearing unit for a vehicle is provided which is advantageous due to low production costs and which is easy to provide in an in-line process for the production of the hub bearing unit. According to the invention, the corrosion protection of the wheel mounting flange of a hub bearing unit is achieved by means of a cathodic protection principle. When exposed to a corrosion environment, the sacrificial gasket will corrode before the wheel mounting flange.
[0008] Hereby, corrosion protection is achieved in a manner that can be implemented as a straightforward and fast inline process, which besides allowing for low production costs, also offers an environmentally friendly solution using a sacrificial principle to prevent rust of the hub bearing unit flange surface.
[0009] By providing a gasket that is electrolytically sacrificial, corrosion protection of the wheel mounting flange satisfying the industry standard ASTM B117 may be achieved. Moreover, the solution according to the invention does not result in loosening of bolt torque when a brake rotor and wheel rim are fixed to the wheel mounting flange. The sacrificial gasket also offers a satisfactory resistance to bolt load and has anti-fretting and failure-safe properties, just as the sacrificial gasket has a satisfactory resistance to hot brake fluid, preservatives and cleaning fluids, and does not adversely affect the performance of the hub bearing unit in the vehicle's wheel end.
[0010] Another advantage of the invention is that a hub gasket made of sacrificial metal according to the invention may be retrofitted to existing vehicle hub bearing units.
[0011] The wheel hub bearing unit according to the invention preferably comprises a rotating ring member with at least one annular track which cooperates with at least one annular track on the non-rotating ring member and accommodates rolling elements in said annular tracks for rotatably mounting the ring members in relation to each other. Accordingly, the hub unit may be provided with either balls, rollers or a combination thereof as rolling elements for the bearing. Moreover, the hub unit may also be provided as a plain bearing.
[0012] In one embodiment, a first ring member is a rotating inner ring and a second ring member is a stationary outer ring of the hub bearing unit. However, as an alternative, the first ring member may be a rotating outer ring and the second ring member may be a stationary inner ring of the hub bearing unit. The rotating ring member of the hub bearing unit comprises at least a radially extending wheel mounting flange.
[0013] The sacrificial metal gasket according to the invention has a thickness of 0.01 to 1.0 mm. In a first embodiment, the gasket may be made of a sheet of sacrificial metal, in which case the thickness of the sacrificial gasket is preferably 0.15 to 0.5 mm. In a second embodiment, the gasket may be made of a steel sheet coated with the sacrificial metal on both sides. The thickness of the gasket is then preferably 0.2 to 0.5 mm. The thickness of the coated sacrificial layer may be between 0.001 and 0.2 mm, and is preferably in the region of 0.01 to 0.05 mm, to enable machining if this is necessary. In one example of the coated steel sheet embodiment, the gasket may be provided with a sealant at its outer annular rim, if it is found necessary to close the exposed steel around the edge of the gasket. Furthermore, in the first and second embodiments of the sacrificial gasket, the surface of the gasket may be passivated by means of e.g. chromating.
[0014] In a preferred embodiment, the rotating ring member of the hub bearing unit is made of a steel alloy. The sacrificial metal is preferably zinc or a zinc alloy, such as zinc-aluminium alloy, preferably ZnAl15. However, it should be understood that other suitable metals may be used for the electrolytically sacrificial metal. The use of ZnAl15, i.e. an alloy with a composition of approx. 85% zinc and approx 15% aluminium, is advantageous as this alloy material is readily available and inexpensive to obtain. Moreover, this particular zinc alloy also provides excellent corrosion protection for various environments.
[0015] The hub bearing unit is provided with fixation means on the wheel mounting flange. The fixation means may be either stud bolts projecting out of the surface of the mounting flange, or threaded holes for receiving attachment bolts for bolting the sacrificial gasket, brake rotor and wheel rim to the mounting flange. The sacrificial gasket is provided with openings corresponding to the bolt positions of the fixation means on the flange surface, so that the gasket does not interfere with the mounting of a brake rotor and/or a wheel on the hub unit.
[0016] In some hub bearing unit designs, the wheel mounting flange has an axial extension, known as a spigot, to facilitate proper centering of the brake rotor and wheel rim during assembly. Corrosion protection on the surface of the spigot is also desirable. In one embodiment of such a hub bearing unit according to the invention, the surface of the spigot may be provided with an anti-corrosion coating or the like. In another embodiment, the sacrificial gasket comprises the radially oriented disc portion and further comprises a tubular sleeve portion, which fits over the spigot. The tubular sleeve portion then provides cathodic protection to the spigot. Furthermore, a protective cap engaging the tubular sleeve portion of the gasket may be provided for enclosing the central opening in the gasket. This cap could also be provided with a sacrificial metal coating and thereby contribute to the cathodic protection of the hub bearing unit.
[0017] The sacrificial gasket may be held in position between the brake rotor and the flange by the mounting forces there between. Alternatively, the sacrificial gasket may be fixed to the mounting flange by gluing or some other adhesive means, like a self-adhesive foil, or by a heat joining technique like welding, or by mechanical means.
[0018] Throughout this patent, the term sacrificial metal is meant to be understood as a metal which in the electrolytic sense is sacrificial compared with the metal used for the rotating ring member and in particular the wheel mounting flange.
DESCRIPTION OF THE FIGURES
[0019] In the following, the invention is described with reference to the accompanying drawings, in which:
[0020] FIG. 1 is a side view of a gasket according to a first embodiment of the invention;
[0021] FIG. 2 is a radial section through a hub bearing unit according to a first embodiment of the invention;
[0022] FIG. 3 is a side view of a gasket according to a second embodiment of the invention;
[0023] FIG. 4 is a radial section through a hub bearing unit according to a second embodiment of the invention;
[0024] FIG. 5 is a side view of a gasket according to a third embodiment of the invention;
[0025] FIG. 6 is a radial section through a hub bearing unit according to a third embodiment of the invention,
[0026] FIG. 7 is a front view of a gasket according to an embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] With reference to FIGS. 2 , 4 and 6 , examples of hub bearing units with rotating inner ring are shown. Such hub bearing units are used in the automotive industry for supporting driven and non-driven wheels and brake rotors, which are secured to a wheel mounting flange 4 . A hub bearing unit comprises an inner ring member 1 , which is rotatably mounted in relation to an outer ring member 2 . The inner and outer ring members 1 , 2 are assembled in a bearing unit, as the inner ring member 1 is provided with at least one raceway, which is an annular track supporting rolling elements 3 , such as balls, which are also accommodated in at least one annular track 6 in the outer ring member 2 . The rolling elements 3 accommodated in the track 7 of the inner ring member 1 are preferably held in place by a separate inner ring element 8 for facilitating assembly of the bearing unit. The outer ring member 2 is fixed to the frame of the vehicle and the inner ring member 1 is assembled on a shaft-like member 20 (see FIG. 6 ), which may be a drive section in the case of a driven wheel or a centering section in the case of a non-driven wheel. The inner ring member 1 is provided with a flange 4 having an exterior surface 5 for receiving a brake rotor and a wheel rim (not shown).
[0028] The mounting flange 4 is provided with a plurality of fixation means 12 , such as threaded holes for receiving mounting bolts (not shown), but could alternatively be stud bolts (not shown) projecting out of the flange surface 5 .
[0029] According to the invention, a gasket 9 is provided for at least substantially covering the flange surface 5 . During use, the mounting flange 4 and in particular the axially outward surface 5 of the flange 4 are exposed to moisture. In order to protect the flange 4 against corrosion, the gasket 9 comprising at least coating layers on either side of an electrolytically sacrificial metal, preferably zinc or a zinc alloy such as ZnAl15, is mounted to the flange surface 5 . Alternatively the gasket 9 is made from a metal sheet made of a sacrificial metal, preferably ZnAl15 or similar zinc-aluminium alloy.
[0030] The flange surface 5 extends radially. In the embodiment shown in FIGS. 1 and 2 , the gasket 9 is of a flat configuration made from a sheet metal, such as a thin steel sheet coated with a zinc alloy, e.g. ZnAl15. The gasket 9 is provided with a plurality of holes 13 corresponding to the fixation means 12 on the flange 4 of the hub bearing unit. As shown in FIG. 7 , the gasket holes 13 are positioned on the gasket 9 so that the gasket 9 fits onto the mounting flange surface 5 without causing any interference with the function of the mounting flange 4 . The outer contour of the gasket 9 can be circular or non-circular, e.g. following the contour of the mounting flange.
[0031] As shown in FIGS. 2 , 4 and 6 , the flange surface 5 may also include an axial extension or spigot 4 a . The gasket 9 shown in FIGS. 3-6 has a radially extending gasket portion 9 r and a tubular sleeve portion 9 a , which is adapted to perform a tight fit around the spigot 4 a on the mounting flange 4 on the inner ring 1 of the hub bearing unit. Hereby, corrosion protection of the surface of the spigot 4 a may also be provided. The tubular sleeve portion 9 a may be provided with the same or a different thickness than the radial portion 9 a of the gasket 9 . The tubular sleeve portion 9 a may be provided as a separate part which may be mounted as a separate piece or joined with the radial portion 9 r . Alternatively, the tubular sleeve portion 9 a of the gasket 9 may be formed integrally during the gasket manufacturing process.
[0032] As indicated on FIGS. 2 and 4 , the gasket 9 may be, provided with adhesive means 14 on the surface (of the radial portion 9 r in the embodiment of FIG. 4 ) of the gasket 9 facing towards the flange surface 5 of the hub unit. The adhesive means 14 may be glue or a self-adhesive foil, such as a double-sided self-adhesive foil.
[0033] With reference to FIGS. 5 and 6 , the shaft-like member 20 mounted in the hub bearing unit may be protected by a cap 10 provided on the gasket 9 . This cap 10 may be provided with a sacrificial metal coating and thereby contribute to the corrosion protection of the hub bearing unit. In addition, the cap portion 10 of the sacrificial gasket may be equipped with sensors, such temperature and/or load sensors, and contain electronics for controlling the wheel end functions and/or the dynamic stability of the vehicle.
[0034] Above, the invention is described with reference to some preferred embodiments. However, a hub unit according to the invention may be executed in many embodiments. For instance, the hub bearing unit may be of the type with rotating inner ring or with rotating outer ring. In this latter case, the outer ring member then comprises at least a radially extending mounting flange for attachment of a brake rotor and wheel rim. The sacrificial gasket as described in any of the above embodiments can also be applied on a hub bearing unit with rotating outer ring. Likewise, the rolling elements 3 may be balls (as described above) or rollers or a combination thereof. Thus, variations of the embodiments of the invention described may be performed without departing from the scope of the invention defined in the claims.
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The invention concerns a wheel hub bearing unit for a vehicle, said hub bearing unit comprising a rotating bearing ring member ( 1 ) and a non-rotating bearing ring member ( 2 ), where the rotating bearing ring ( 1 ) has at least a radially extending wheel mounting flange ( 4 ) with a reference flange surface ( 5 ), wherein a gasket ( 9 ) with at least a sacrificial metal gasket surface is provided on the flange surface ( 5 ). Hereby, corrosion protection of the surface of the wheel mounting flange of a hub bearing unit is realized in a cost-effective manner.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority as a continuation of U.S. Non-Provisional application Ser. No. 12/271,108, filed Nov. 14, 2008, now U.S. Pat. No. 7,910,646, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 60/988,530, filed Nov. 16, 2007, the entirety of which are each expressly incorporated by reference herein.
FIELD OF THE INVENTION
This invention relates to a polymeric composition and method of modifying the surface of the polymeric composition to produce a film or article with a reduced coefficient of friction (COF) and improved release properties. The reduced coefficient of friction improves both the slip and anti-blocking properties of the material as well aiding in processing of the polymeric material. Additionally, the invention improves demolding and release of the polymeric material from other polymeric surfaces or adhesives as well as metal molding surfaces.
BACKGROUND OF THE INVENTION
It is often desirable to modify the surface interface of polymeric materials to produce a variety of related surface effects such improved slip or lubricity, reduced blocking, and to lubricate process equipment. It is also desirable to modify polymeric surfaces to improve release of adhesives and promote demolding or adhesion of other materials from a polymeric composition surface. It is also generally understood in the art that improved slip and reduced blocking are a function of reduced coefficient of friction (COF) for the particular composition. A variety of prior art additives and modifiers have been developed to attempt to provide these attributes to different types of polymeric materials. These additions and modifiers can be classified as anti-block additives, slip aids, COF modifiers and release aids, and have somewhat related but different purposes and attributes, as described below.
1. Anti-Block Additives
Polyolefin resins are regularly used to produce sheets and films. These sheets and films are stacked or rolled in storage and use. The sheets or rolls of film can adhere to each other and become very difficult to separate due to surface tackiness and other molecular binding mechanisms. This phenomenon is called blocking. Anti-blocking agents are commonly and interchangeably called slip aids. Anti-blocking agents are commonly added to the melt phase of the resins during compounding or extrusion to mitigate this blocking effect.
The most common approach to reducing blocking behavior is the use of certain particulates as additives that are dispersed in the resin. These anti-blocking additives take various forms such as Zeolite, inorganic silicates, silica or powdered silicone rubber. However, these dispersed solids can produce a strong haze effect and can produce unattractive films. Further, like other proposed solutions, this solution for blocking of these films can create problems with regard to reducing the COF of the film. For example, a polypropylene film is often laminated to other films. In particular, glassine paper is commonly laminated to polypropylene film. Such a laminate, when provided as a thin surface layer containing finely divided inorganic material, exhibits significantly higher COF values than does the unlaminated polypropylene film as a result of the particulate additive present in the polypropylene film. Such laminates are known to perform marginally at best on conventional form, fill and seal machines.
Another prior art attempt to reduce blocking is disclosed in U.S. Pat. No. 4,327,009 which describes the use of polyglycols and other low molecular weight additives to polyolefin films to reduce blocking. These additives are selected due to their propensity to migrate to the surface, and as such suffer from the limitations created by the migrating additives. The migration behavior of these or any other type of additive to a polymeric compound is a function of the solubility parameter of the additive in relation to that of the base polymer and the molecular weight of the additive. The more mismatched the solubility parameters and the lower the molecular weight, the faster the additive can migrate to the interface of the polymer and cause undesirable effects thereon, such as an increase of COF.
2. Slip Aid Additives
Slip aids also reduce blocking but further aid in lubricating handling and converting equipment down stream from extrusion or molding. Injection molded parts also benefit from slip aids when the slip aids are incorporated within the material formed into the parts as the parts have improved lubricity against each other when handled. This reduces marring and enables the material/parts to flow better when handled in bulk.
The lubricity effects discussed herein are to be distinguished from the industry term “internal lubricant” which is an additive class of materials that effectively “plasticizes” the polymer melt to improve processing and flow.
Many slip agents based on silicones and fatty amides, such as erucamide and oleamide, are well known in the art. Although they do reduce the coefficient of friction, lubricate and improve release, their effectiveness depends upon their ability to migrate to the surface of the film, which is required for these slip aids to be effective. In addition, the development of the desired level of anti-block or slip for the film composition in which the slip aids are utilized is strongly dependent upon the type slip aid used, the amount used, the storage time of the film and storage temperature. The heat history of the film while in storage, shipping and during subsequent converter processes also significantly affects the surface lubricity effect and is thus difficult to predict and control. In addition, the presence of fatty acid amides used as a slip aid that migrates onto the exterior of the film surface, while decreasing the COF of the film, unfortunately results in visible adverse appearance effects for the film, manifested by an increase in haze, a decrease in gloss and the presence of streaks. These fatty amide slip aid materials also adversely affect the adhesion of solvent and water-based inks, coatings and adhesives.
The migration of silicones utilized as slip aids can also cause similar downstream processing problems as the amides. Recent advances in silicone additive technology have been made to reduce the migration rates of the silicones and siloxanes. However, these modifications made to the silicone slip aids often cause the silicone slip aids to suffer from incompatibility with the resins which makes compounding very difficult. As a result, consistent compounding of these silicone materials is recognized in the industry as being very difficult to achieve. Commercial offerings of these materials can also still migrate to a small extent and continue to cause downstream issues due to this migration.
3. COF Modifiers
Polypropylene films have found wide acceptance in the packaging industry, especially as a food packaging agent, because of their superior physical properties. Polypropylene film, usually biaxially oriented, is characterized by high tensile modulus and stiffness, and excellent optical clarity and a certain degree of moisture resistance. Moreover, polypropylene film is highly pervious to gases and air. However, polypropylene possesses one major disadvantageous property, namely, a high inherent coefficient of friction (COF). This high COF significantly complicates the processing of the polypropylene film. In particular, the polypropylene film processing is impeded by poor transport, caused by its high COF, over rollers, guides and the like. In addition, the high COF creates film storage problems. In particular, because of its high COF one layer of polypropylene film sticks to those above and beneath it, creating the blocking effect referenced earlier.
This serious disadvantage of polypropylene film is well known to those skilled in the art. Thus, many proposed solutions to overcome this major deficiency have been proposed in the art. One such proposal has been to incorporate additives in the polypropylene resin processed to form the film. A favorite additive utilized for COF reduction are slip aids, specifically fatty acid amides. These amides decrease the COF of the polypropylene film as they migrate to the film surface after heat treatment and aging. Although this method has been used, actual COF is a function of the heat history to which the film has been exposed during shipping, storage and processing. As such, it is subject to wide variation. More significantly, the presence of fatty acid amides on the film surface oftentimes adversely affects the appearance of the film as manifested by decreased gloss and the presence of streaks, as discussed previously.
Another serious disadvantage of using fatty acid amides is the detrimental effect that the fatty acid amide additives have on polypropylene film surface wetability and adhesion when the additive has migrated onto the surface of the film to provide the COF reduction. This adverse adhesion characteristic caused by the additives applies to coating, inks, adhesives and the like, especially in water based forms that are applied to the surface of the films.
It is also known to coat polypropylene films with certain fatty acid amides to impart lubricating and anti-blocking characteristics, as opposed to incorporating the amines within the film as an additive. However, the application of such coatings by the film manufacturer is not particularly attractive because of the added equipment and corresponding expense of doing so, as well as the requirement that the amine coatings be applied as solutions in organic solvents. Health and safety factors dictate against the in-plant utilization of organic solvents in coating processes undertaken during the film manufacture.
Other slip additives have been suggested for use with thermoplastic films to overcome the inherent problem of high COF in thermoplastic films. One such solution, as disclosed by U.S. Pat. No. 4,302,506, is the use of a latex coating containing stearamidopropyl-dimethyl-beta-hydroxyethylammonium nitrate and a crosslinkable acrylic copolymer. However, this method requires post treatment of the film or article by applying the additive as a coating to the surface of the polymeric film. While avoiding the problems caused by having to utilize organic solutions in applying the coating, this alternative additive is still undesirable because it requires downstream coating and curing equipment, and the additional expense associated with them.
4. Internal Mold Release and Adhesive Release Aids
It is also desirable to incorporate internal mold release aids into thermoplastics and thermoset resin compositions because these release aids assist in demolding extruded or cured parts formed from the thermoplastic or thermoset resins from production molds and processing equipment. For example, U.S. Pat. No. 5,883,166 describes the use of a liquid mold release agent for unsaturated polyester resins. However, in general, liquids are not commercially feasible for use as release aids due to their low molecular weight which allows the additive to migrate out of the compound too quickly, subsequently causing a variety of problems with the molded product in commercial use, such as those described previously.
The above discussion reflects the need in the art for improved additives for polypropylene and other polyolefin films that are capable of creating films characterized by improved anti-blocking characteristics and decreased COF. The same desired effects provided by additives of this type should also extend to other polymeric materials, such as the materials utilized to form the molds in which products are formed from these polyolefin films, which could potentially be made from a polyolefin of other suitable compound including additives of this type, to improve the release of the product from the mold when a product formed from a polymeric material is molded or cured within or in proximity to the mold.
In addition, when providing these attributes, it is desirable to have an additive material that has minimal or no migration within the polymeric compound, such that the additive is considered essentially permanent, to avoid the problems associated with the migration of prior art additive onto the surface of the polymeric film or item. In addition to the non-migratory properties of the additive, it is incumbent that the particular additive or compound utilized for the improvement in film slip property also not correspond or create to any decline in any other properties of the film in which the additive is utilized, which is typical of the previous additive solutions advanced in the prior art.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, the present invention provides a method of producing a polymeric composition unexpectedly having reduced COF, and thus improved slip, reduced blocking, improved release and enhanced demolding capability by introducing an additive into the polymeric composition that is formed of a high molecular weight, high melting point ethoxylated compound, and the composition formed with the additive. The high melting point of the additive enables the additive to be stable at elevated temperatures when used in various polymeric films, and the high molecular weight of the additive causes the additive to be essentially non-migratory within the polymeric compound. Thus, the resultant polymeric composition formed with the additive of this invention also unexpectedly demonstrate no detrimental effects on the beneficial properties of the polymeric film as opposed to that seen as a result of the use of other prior art additives, including wetability and adhesion of paints, inks and coatings to the film that are caused by the migration of the prior art additives within the films.
According to another aspect of the present invention, it has been unexpectedly discovered that the class of materials disclosed within as inventive for use as the polymeric composition additives also allows for the release of adhesives from polymeric films formed utilizing the additives. This discovery allows the direct extrusion of ready-to-use films incorporating the additive that can be utilized as a release liner without the requirement of coating and curing of a separate release coating onto these films. These liners can be used in a variety of applications such as tape backing, pressure sensitive label liner, linerless labels, release separator sheets, shingle release tapes and other traditional release liner applications. In this application, subsequent adhesion is important and the greatly reduced or eliminated migration of the additive is critical to the beneficial performance of the films incorporating the additive as a release liner.
The primary material class that has unexpectedly been discovered as capable of being utilized for these purposes as the additive is a non-migratory, high melting point, high molecular weight ethoxylated compound. Though low melting point, low molecular weight, migratory ethoxylated compounds have been disclosed for other uses in the prior art, this class of compounds has not been previously disclosed for use as a COF modifier, slip aid, release aid, and/or anti-blocking additive for polymeric compositions.
More specifically, for example, U.S. Pat. No. 5,849,209 (the '209 patent) describes the use of low melting point, low molecular weight ethoxylated amine additives as wetting agents compounded into the thermoplastic mold material used in the molding process of contact lenses. However, the additive materials disclosed in these references are amine compounds, and, as described previously, thus are migratory within the polymeric materials into which they are added in order to provide the improved wetability of the mold materials, as opposed to the non-migratory, high melting point, high molecular weight additives of the present invention. In addition, these references disclose only that the particular migratory ethoxylated amine additives improve wetability by minimizing the surface tension of the mold materials, without any disclosure or suggestion of the use of non-migratory ethoxylated additives as an additive for reducing the COF of a polymeric film, or to improve the demolding properties of the mold or of the materials being formed in the molds.
Further, U.S. Pat. No. 4,327,009 (the '009 patent), which is incorporated by reference herein in its entirety, discloses the use of liquid ethoxylated compounds as anti-block, non-slip additives for olefin polymers. However, the '009 patent specifically states the importance of the use of low molecular weight ethoxylated materials for the particular slip and blocking performance provided to the olefinic films. In particular, the '009 patent teaches that low molecular weight liquid ethoxyalted additives are required for adequate slip and block performance because of the need for the additives to migrate to the surface of the olefinic polymer to provide the desired benefits. This teaching is directly opposite to the discovery of this invention that utilizes very high melting point, high molecular weight additives for improved control of migration of the additive within the polymeric compound, and improved melt processability.
Additionally, U.S. Pat. Nos. 7,037,964 (the '964 patent) and 6,784,235 (the '235 patent) describe the use low molecular weight alcohol ethoxylates as an anti-fogging melt additive for polyolefin to produce anti-fogging films. The '964 and '235 patents explicitly state that in the embodiments where the ethoxylated additives are compounded into the polymeric materials utilized to form the films, the anti-fogging additive will migrate out of, or exude to the surface of the film in order for the ethoxylated anti-fogging agent to be effective. Again, this migration of the additive is exactly opposite to the additive and composition of the present invention, but is consistent with the prior art teachings that additives of this type need to migrate to the surface of the films to be effective. Further, no disclosure of the applicability of the low molecular weight ethoxylated compounds disclosed in these patents to reduce blocking, or as a mold release agent is found in these patents, as the only mention of any component having these properties is in the discussion of other additive that can be added to the film composition in addition to the anti-fogging additive.
Additionally, U.S. Pat. No. 4,908,063 (the '063 patent) discloses an additive composition for waterbased inks utilizing alcohol ethoxylates which, among other benefits, claims reduced coefficient of friction for the ink composition. However, the '063 patent is exclusively directed towards ink compositions including water and the additive, such that there is no discussion or suggestion in the reference that proposes the use of the additive as a melt additive for thermoplastics or other polymeric compositions for the reduction of the coefficient of friction and/or improving release or slip properties as for the additive and composition of the present invention.
As a result, the high melting point, high molecular weight, non-migratory ethoxylated compound utilized as the coefficient of friction reducing and/or release or slip aid additive of the present invention, and the polymeric compounds formed utilizing the additive provide significant and unexpected benefits to the numerous types of items that can be formed using the polymers modified by these additives.
Numerous other aspects, objects and advantages of the present invention will be made apparent from the following detailed description, taken together with the drawing figures.
DETAILED DESCRIPTION OF THE INVENTION
The composition of the invention is a thermoplastic polymer, a thermoset resin or other polymer-based composition containing at least one melt processable ethoxyalted additive that is essentially non-migratory, that reduces the COF of the resultant compound, and also improves the demolding properties and adhesive behavior of the compound.
Thermoplastic polymers that can be utilized in this composition are primarily polypropylene and polyethylene. Not to be limited to but suggested by reference, other engineering resins such as nylon, polyetheretherketone (PEEK), ethylene vinyl acetate (EVA), styrenics, styrene acrylonitrile (SAN), polyester terepthalate (PET) as well as thermoplastic elastomers, TPUs and TPVs can also be utilized in this composition. No limitation is anticipated in the selection of thermoplastic, thermoset or polymeric resins which can be useful in the manufacture of compositions according to in this invention.
The composition of this invention may also contain one or more additional additives commonly known in the art without interference with the performance of the additive of this invention. However, the presence of metal stearates or similar polar bonding materials is known in the art to have antagonistic effects on other surface active ingredients. These interfering additives compete for interfacial sites and can reduce efficacy, and therefore are not included within the compositions of the present invention.
Potential Applications
One important application for this inventive composition is in films produced by the blown film process, extruded films or co-extruded films. Some specific potential applications of such films are films to be used for release liners, films for packaging, films for agricultural or greenhouse use, co-extruded films and graphics films.
However, injection molded parts and profile extrusions can also benefit from reduced surface friction and release properties provided by the additive and composition of the present invention when used to form the parts. In addition, blow molded parts can benefit from the surface lubricity imported by the inventive composition when used to form the parts. Bottles and other parts formed in this manner with the composition and additive of the present invention are easier to handle in bulk and can pack more efficiently in totes and boxes. Less marring of the film form with the composition and additive of the present invention occurs with the reduction of the COF. Bottle caps and other closures and also easier to remove and operate with the improved surface lubricity provided by the composition and additive of the present invention.
It is also anticipated that this inventive composition is utilizable in rotomolding applications to assist in demolding, whether by improving the release properties of the mold or of the product being formed within the mold. Also, thermoset applications requiring heated mixing or curing are excellent candidates for the inventive additives disclosed here. The temperature during processing must be sufficient to liquefy the additive and disperse it throughout the compound. If this is performed the surface properties and release behavior will be improved.
In accordance with the present invention, a thermoplastic or thermoset resin is compounded with at least one ethoxylated compound having the following general structure:
R—(CH 2 CH 2 O) x H
The ethoxylated compound is melt processable and has only limited or no migration ability at end use temperatures, T<150° F., for example. The inventive materials are solid at these temperatures, as they have melting points of between 70° C. and 110° C., and more preferably between 85° C. and 95° C., and thus have little or no migration when compounded into a polymeric system. The ethoxylate can have from 1 to 100 ethylene oxide units. The number of ethoxylate units is very influential on its orientation at the interfaces and subsequently its performance. Further, the molecular weight of the ethoxylated chain preferably falls between 100 amu and 4500 amu, with a range of 115 amu to 1900 amu being especially preferred. The weight percent of the ethoxylated chain in the overall weight of the additive can be from about 20% w/w to about 90% w/w.
The structure and molecular weight of the R group that has been ethoxylated is also very important to the performance of the additive. The R group must either be of sufficient molecular weight to make it a solid or wax at post processing use temperatures, i.e., at least 300 amu, or preferably between abut 350 amu and about 700 amu, with a range of between about 400 amu to about 500 amu being especially preferred. The R group can also have other structural elements that significantly retard migration of the molecule after processing. The R group structure must also allow for the additive to be melt processable or at least melt at compounding and production temperatures. The R group may be but not limited to linear alcohols, branched alcohols, carbohydrates, cyclic containing alkyls, alkyl esters, phosphate esters, polymeric alcohols, and the like. Individual constituents on the R group do not change the inventive nature of the additive, except for enhancing the ability of the additive to be non-migratory within the polymer based upon the size of the R group.
The currently preferred embodiment of the invention is a polymer or resin combined with 0.05 to 30 parts or percent by weight, and more preferably 1.0 to 10.0 parts or percent by weight of at least one COF reducing compound of the formula:
CH 3 CH 2 (CH 2 CH 2 ) a CH 2 CH 2 (OCH 2 CH 2 ) b OH
where a is >9 and b is 1 to 100 as an additive in the polymer or resin. In one preferred embodiment, the compound can have the above formula where a is greater than 25. In another preferred embodiment, the compound can have the above formula where b is between 10 and 100, and more preferably between 40 and 75.
In further accordance with the present invention, a thermoplastic resin or compound including the COF reducing additive may be made into a film by cast extrusion or by being blown, it may be extruded into a profile or injection or blow molded into an article or used to form a mold in which item formed of other various polymeric materials are formed. In still further accordance with the present invention the thermoplastic composition including the additive can optionally contain other performance additives such as antioxidants, pigments, fillers, additional lubricants, impact modifiers and other additives traditional incorporated into thermoplastic compositions for performance.
EXAMPLES
The following examples are provided for reference and are not intended to limit the application of the inventive composition.
The following list provides some preferred embodiments of the inventive additives of the present invention in comparison with prior art silicone additives which were tested to determine the differences in the performance characteristics of the polymers and resins admixed with these additives.
Ethoxylate A is a compound with the formula CH 3 CH 2 (CH 2 CH 2 ) a CH 2 CH 2 (OCH 2 CH 2 ) b OH, where a has an average number between 14 and 15 and b has an average between 2 and 3. Ethoxylate B is a compound with the formula CH 3 CH 2 (CH 2 CH 2 ) a CH 2 CH 2 (OCH 2 CH 2 ) b OH, where a has an average number between 14 and 15 and b has an average between 10 and 11. Ethoxylate C is a compound with the formula CH 3 CH 2 (CH 2 CH 2 ) a CH 2 CH 2 (OCH 2 CH 2 ) b OH, where a has an average number between 14 and 15 and b has an average between 40 and 45. For comparison Silicone A is Trilwax Si 900 a commercially available alkyl-modified siloxane used in high temperature release and lubricant applications available from Trillium Specialties. For comparison Silicone B is commercially available ultra high molecular weight silicone additive (Genioplast P) produced by Wacker Chemie and is known in the art as a process aid and surface lubricant. For comparison Silicone C is a semi-commercial silicone compound produced for use as a melt additive to produce release effects on film consisting of ultra-high molecular weight dimethyl siloxane gum and an intermolecular bonding agent.
These compounded materials were produced by mixing the selected additives with a 0.65 MI/0.904 Density Homo-polymer Polypropylene using a Haake Torque Rheometer with 20:1 L/D Bradender twin screw counter rotating extruder with 4 temperature segments at an RM ranging from 30 to 50 and a temperature profile of between 375 and 475.
Films were produced using a 25:1 L/D Brabender single screw with a blown film die. The extruded blown film was collected on a vertical blown film tower. During extrusion the torque values were measured at 30 rpm to observe any process aid attributes resulting from the increased lubricity. The results in Table 1 show that the inventive compounds process as well as those silicones normally utilized as a process aid.
TABLE 1
% Additive
Additive
Torque
1
0.0%
Control
30.00
2
5.0%
Silicone B
12.00
3
2.5%
Ethoxylate B
14.50
4
2.5%
Ethoxylate A
9.00
5
2.0%
Silicone A
9.60
Static coefficient of friction measurements were performed film on film with an increasing angle arm device. The test specimens approximately 1″×4″ are attached to the aluminum lever arm and a 150 g steel block with a face dimension of 1′×2″. The arm raises until the block begins to move. The angle of the arm is measured when the blocks slides and in converted to COF by the calculating the tangent of the angle. The dynamic surface tension was directly measured. However, visual observations were made on the amount of pressure required to keep the “slide” of the block going. Most materials are tacky and have a start/stop behavior, suggesting low dynamical COF while materials that have a smooth slide with low pressure generally have a low dynamic surface tension. The results are disclosed in Table 2 and demonstrate that the ethoxylate additives of this invention can reduce the COF as much or more than commercial silicones used for this purpose.
TABLE 2
% Additive
Additive
COF
1
0.0%
Control
0.42
2
5.0%
Silicone B
0.34
3
2.5%
Ethoxylate B
0.36
4
2.5%
Ethoxylate A
0.18
5
2.0%
Silicone A
0.34
Demolding was evaluated by placing compounded pellets of the polymer and respective additives into aluminum mold dishes and heated for 2 hours at 210° C. so the pellets melted and coalesced. The molds were cooled to room temperature and the molded puck was removed from the mold. The difficulty of removal was given a scale from 1 to 10 where 1 is given when the puck falls out of the mold with no force and 10 being fused to the mold and destruction of the puck would be necessary. The scale in between is the approximate force required to separate the puck from the mold. The clarity of the puck was observed as well. The control material in highly translucent and that was given a 1 rating and 2 indicates an significant increase in haze and 3 is opaque. These results are provided in Table 3.
It can be seen that the use of the ethoxylates have a dramatic impact on demolding over the control. The results also show that the ethoxylates do not dramatically hurt the haze as much as other demolding additives. Most surprising is the performance compared to Silicone A and B which are expected to produce excellent demolding results. It is also observed in trials 3 and 4 that the ethoxylates can be synergistic when used in conjunction with other additives. Trials 7 and 8 demonstrate a concentration dependence. It is anticipated that each individual application and compound will have a specific optimum concentration of additive.
TABLE 3
Adhesion
Clarity
Release Additive
Rating
Rating
1
Control
9.5
1
2
2.5%
Ethoxylate A
3
2
3
2%
Ethoxylate A +
2
1
3%
Silicone A
4
5%
Silicone A
3.5
1
5
10%
Silicone B
2
3
6
2.5%
Ethoxylate C
2
1
7
5%
Ethoxylate B
2.5
2
8
2.5%
Ethoxylate B
1
1
Adhesive properties or release was measured by testing the blown films produced under TLMI 180 peel test procedures using TESA tape 7475 pulled at 300 inches per minute. The tape laminated samples were conditioned at 140° F. for 20 hours before peeling. For subsequent adhesion, the Finat 11 test procedure was run which applies an unused piece of TESA tape and a piece of tape that has been in touch with the substrate for the 20 hr oven test, as in the peel test. The tapes are allowed to dwell on a clean steel plate for twenty minutes and pulled at 12 inches per minute at a 180 degree angle. The result is divided by the control result to get the % subsequent adhesion.
Table 4 demonstrates that ethoxylates can act as a melt additive release agent to produce ready to use release liner films. The control was welded to the tape and could not be removed. Ethoxylate C showed release comparable to Silicone C which is a melt additive intended to perform the same function. The most surprising observation was the high percentage subsequent adhesion. This suggests that the additive is non-migratory even under harsh heated storage conditions.
TABLE 4
% Additive
Additive
300 ipm Release
% Sub. Adh
1
0.0%
Control
Welded
NA
2
10.0%
Silicone C
375.00
94
3
2.5%
Ethoxylate C
487.00
100
In this example, the kinetic coefficient of friction modification of the invention was demonstrated with a thermoplastic elastomer or plastomer. The polymer Dow Chemical Affinity PL1880G was melt processed in a twin screw extruder with 2.5% of ethoxylate A. The resultant compound was made into a 5 mil film via blown film processing. The films were measured for kinetic coefficient of friction on a Instumentors 3M90 Slip/Peel testing apparatus following ASTM D-1894 specifications as closely as possible, and the results are shown below in Table 5.
TABLE 5 Kinetic COF Film with no additive 0.75 Film with 2.5% Ethoxylate A 0.56
Due to the high level of blocking or tackiness of thermoplastic elastomers it is common for resins to be supplied with anti-block additive present. Further control of COF or more improved anti-block may be desired. In another example, the compatibility with other anti-block agents is demonstrated with a blend of ethoxylates in a plastomer. Using the Dow Affinity 1880G polymer, 3% of 1:1 blend of Ethoxylate A and C were melt processed with 1.25% anti-block additive concentrate 100456 produced by Ampecet, in a twin screw extruder. Subsequently, a 5 mil blown film was produced. Kinetic COF was measured in a process analogous to above, with the results shown below in Table 6.
TABLE 6 Kinetic Film With Antiblock COF Film with no COF additive 0.40 Film with additive blend 0.23
In both cases, substantial drop in kinetic COF is demonstrated. Surprisingly, films produced with the ethoxylated additives did not show any change in visual clarity or haze. The typical tacky surface character of the Affinity resin was eliminated.
Various other alternatives are contemplated is being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.
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This invention relates to a composition and method of modifying the surface of a polymeric to produce a film or article with a reduced coefficient of friction (COF) and improved release properties. The reduced coefficient of friction improves both the slip and anti-blocking properties of the material as well aiding in processing of the polymeric material. Additionally, the invention improves demolding and release of the polymeric material from other polymeric surfaces or adhesives as well as metal molding surfaces.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of the provisional application entitled “Protective Container for Oral Appliances”by Patricia M. Brooks, Ser. No. 61/619,419 filed on Apr. 3, 2012 and is hereby incorporated by reference in its entirety.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
JOINT RESEARCH AGREEMENT
Not applicable
SEQUENCE LISTING
Not applicable
FIELD OF THE INVENTION
The present invention relates to the field of containers for oral appliances.
BACKGROUND OF THE INVENTION
Currently a of number oral appliances exist for use in orthodontia, prosthetics and protection. There is a need for securing and protecting these appliances when not in use. There is also a need for enabling easy user access to these appliances when needed.
SUMMARY OF THE INVENTION
In one embodiment, the protective container for oral appliances, also referred to simply as the container, has an outer zip-able cover. The outer zip-able cover is like a clam shell with two halves hinged in the back closing with a zipper at the sides and front. A strap attached to the container at the back near the hinge provides a way to attach the container via a clip to a belt, belt loop, back pack or the like. This allows the container to be easily carried reducing the risk of loss. When the container is unzipped and opened, a retaining cord is exposed. This retaining cord is attached to the interior at the back of the container approximately parallel to the inside surface of the hinge.
The retaining cord is useful for constraining an oral appliance from falling out of an open container. Examples of oral appliances include, but are-not limited to, mouth guards, retainers, dental braces, dentures, bridges and prosthetics.
In another embodiment, a hard inner liner, also clam shell in shape, fits inside the container. The oral appliance fits inside this hard inner liner. The hard inner liner adds additional protection to the oral appliance reducing possibility of crushing or breakage if the container is dropped or stepped upon. The hard inner liner is also hinged at the rear. The hard inner liner further has a notch at opposite sides of the liner hinge to allow the retaining cord to fit inside the liner. This allows the hard inner liner to close more tightly. The retaining cord acts to constrain both the hard inner liner and the oral appliance inside the container. The combination of the pieces allows for easy storage and retrieval. The retaining cord on the inside of the container holds the hard inner liner securely in the zip-able cover.
In another embodiment, the container has a mesh net pouch attached to one or both sections of the clam shell to provide storage for dental supplies. Examples of dental supplies include, but are-not limited to, floss, toothpicks, dental wax or gum. An elastic cord at the open end of the mesh net pouch acts to retain the dental supplies in the pouch.
BRIEF DESCRIPTION OF THE DRAWINGS
The summary above, and the following detailed description will be better understood in view of the enclosed figures which depict details of various embodiments. It should however be noted that the invention is not limited to the precise arrangement shown in the drawings and that the drawings are provided merely as examples. Like reference numerals refer to like parts.
FIG. 1 shows one embodiment of the container in the open position.
FIG. 2 shows a close-up of one embodiment of the container emphasizing the retaining cord.
FIG. 3 shows a close-up of one embodiment of the container emphasizing the strap and clip.
FIG. 4 shows an embodiment of the container with the removable hard inner liner fitted in the container.
FIG. 5 shows a close-up of one embodiment of the container emphasizing a portion of the removable hard inner liner.
FIG. 6 shows a close-up of one embodiment of the container emphasizing a portion of the removable hard inner liner.
FIG. 7 shows another embodiment of the container with a net mesh pouch and elastic lip.
FIG. 8 shows an embodiment of the rear of the container and the hinge.
FIG. 9 shows an embodiment with the closed zipper adjacent the strap.
FIG. 10 shows an embodiment with an oral appliance.
FIG. 11 shows an embodiment with an oral appliance inside a liner.
FIG. 12 shows one use of an embodiment worn on the waste of a user.
FIG. 13 shows a flow chart demonstrating some of the uses of the protective container.
DETAILED DESCRIPTION
FIG. 1 shows one embodiment of the protective container for oral appliances 10 with the outer zip-able cover arranged as two clam shell halves also called container halves 110 . A zipper handle 115 zips together the zipper teeth 117 to close the outer zip-able cover halves 110 . The outer zip-able cover halves meet in the back at a hinge 120 which enables the container halves 110 to open allowing access to the interior space of the container 112 . In one embodiment, the two clam shell halves and the hinge are formed from a single piece of material. In other embodiments the two container halves and hinge can be separate pieces that are joined together. The term clam shell or clam shell like is not be understood as specifying a particular shape, as many shapes are possible. While a zipper is shown in the following figures, other types of closures such as hook and latch, button and hole, and other types of closures are also possible A strap 130 is secured to the cover at the back near the hinge 120 . A clip 140 attached to the strap 130 allows the container 10 to be attached to a belt, belt loop, backpack, luggage or other items. This attachment reduces the risk of loss.
In use, the user unzips the zipper 115 and opens the two cover halves 110 providing access to the interior 112 of the container 10 . The user then places the oral appliance and possible accessories or dental supplies into the interior 112 of the container 10 and closes the zipper 115 . The user then attaches or clips the container 10 to an article of clothing, a backpack, fanny pack or other item for safe-keeping and transport. The strap 130 and clip 140 enable the container 10 to be securely transported while reducing the risk of loss.
FIG. 2 shows a close-up of one embodiment of the container 10 with a retaining cord 150 . The retaining cord is typically made of a stretchable elastic material, making it an elastic retaining cord, but it can be made of other materials. The retaining cord 150 is anchored at both corners 152 of the cover halves 110 near the hinge 120 . The elastic retaining cord 150 is stretched or tensioned across the hinge 120 in the interior space 112 . The retaining cord 150 can be pulled out from proximity with the hinge 120 while an oral appliance is placed in the interior space 112 of the container 10 . The elasticity of the retaining cord 150 restrains the oral appliance (not shown) toward the hinge 120 and reduces the risk of the oral appliance falling out of the container 10 .
In use, the user simply pulls the retaining cord 150 away from the hinge 120 and loops the retaining cord 150 over or around the oral appliance. Once released, the natural elasticity of the retaining cord 150 holds the oral appliance against the hinge 120 and the interior 112 of the container 10 .
FIG. 3 shows a detail of the strap 130 and clip 140 of one embodiment of the container 10 . The strap 130 attaches to the container 10 and the outer zip-able cover halves 110 near the hinge 120 of FIGS. 1 and 2 . The strap can be made of a number of materials including but not limited to, an elastic loop, a braid, a cord or an extension of the hinge material itself. The clip 140 is depicted as a carabiner. Other versions of clip 140 are possible.
FIG. 4 shows one embodiment of the container 10 with a removable hard inner liner 160 . The container 10 may be used with or without the hard removable inner liner 160 . The hard removable inner liner 160 , or simply liner 160 for short, is similar to the outer zip-able cover halves 110 in that it also has two clam shell like halves 164 that come together to enclose the liner interior 168 . The liner 160 can be made of a single piece of plastic with a live hinge and compliant catch to hold it closed. Other versions of the liner 160 can be made of metal with other types of hinges and closures. Other embodiments of the liner 160 can use the outer zip-able cover halves 110 of FIG. 1 to hold the liner closed when the zip-able halves force the liner halves 164 together.
FIG. 5 shows a close up view of one embodiment of the removable hard inner liner 160 fitted into the outer zip-able cover halves 110 of the container 10 .
FIG. 6 shows a close up view of one embodiment of the removable hard inner liner 160 fitted into the outer zip-able cover halves 110 of the container 10 of FIGS. 1 and 2 . The hard inner liner, simply called the liner, 160 is composed of two removable hard inner liner halves 164 . Notches 165 , of which one is shown, are near the hinge area in the liner interior 168 . The retaining cord 150 passes through the notch 165 into the interior of the liner 168 to retain the liner inside the container 10 . The retaining cord 150 can be used simultaneously to hold an oral appliance, not shown, inside the liner.
FIG. 7 shows a view of one embodiment of the container 10 with a mesh net pouch 170 on one of the outer zip-able cover halves 110 . The mesh net pouch 170 has one or more elastic lips 175 to help keep the contents of the mesh net pouch 170 from falling out. In another embodiment the container has a mesh net pouch attached to one or both sections of the clam shell to provide storage for dental supplies or accessories. While a mesh net pouch is shown in FIG. 7 , other types of pouches are possible. For example a solid fabric pouch or pleated pouch with an elastic lip for closure can be used in conjunction with or in place of the mesh net pouch. Examples of dental supplies include, but are not limited to, floss, toothpicks, dental wax or gum. In FIG. 7 the contents are depicted as a toothpick and two floss devices.
In use, the user opens the container 10 to expose the mesh net pouch 170 . The user pulls the elastic lip or lips 175 away from the mesh net pouch 170 to place materials into, or retrieve materials from, the mesh net pouch 170 .
FIG. 8 shows a rear view of one embodiment of the container 10 .
FIG. 9 shows an embodiment where the zipper handle 115 , in the closed position is adjacent the strap 130 and clip 140 . In this embodiment, when the container 10 is worn on the waist for example, a user can unzip the zipper handle 115 without removing, unclipping or repositioning the container 10 .
FIG. 10 shows an oral appliance 180 inside the container 10 . The elastic retaining cord 150 stretches across the oral appliance 180 and holds it inside the container 10 . In this configuration, the container 10 can be opened in any position without the oral appliance falling out. In some embodiments, the oral appliance 180 can even be retrieved with one hand. Note that in FIG. 10 the oral appliance is depicted as a mouth guard. Examples of other oral appliances include, but are not limited to, retainers, dentures, partials, bridges, orthodontic head gear.
FIG. 11 shows an oral appliance 180 inside a liner 160 which is itself inside the container 10 . The elastic retaining cord 150 stretches across the oral appliance 180 and holds it inside the liner 160 . This resulting tension also holds the liner 160 inside the container 10 . In this configuration, the container 10 can still be opened in any position without the oral appliance falling out. The liner 160 also is restrained inside the container 10 . There are environments where a user may choose to have additional protection of the oral appliance. In such cases, the liner 160 can be employed. In situations where the extra protection is not required, the container 10 can be used without the liner 160 . In some embodiments, the oral appliance 180 can even be retrieved with one hand, while the liner 160 remains constrained in the container 10 .
FIG. 12 shows one situation described for FIGS. 10 and 11 . In FIG. 12 , the container 10 is suspended from a belt or belt loop of a user. The clip 140 attaches to the belt or belt loop and the container 10 hangs from strap 130 . In this situation, the zipper handle 115 is in the closed position when the zipper handle is adjacent the strap 130 . A simple downward pull on the zipper handle 115 allows the user to open the container 10 , in many cases, with just one hand.
Not only are metals such as aluminum, steel, brass and other alloys suitable, but also many different types of plastics, polymers, fabrics and composites work well. A mix of materials is also possible. For example the outer zip-able cover halves 110 can be of a fabric, plastic or a combination of the two. The removable hard inner liner 160 can be made of plastics, metals or other materials. Materials can be man-made or natural.
Material sets can be chosen for all components; container 10 , outer zip-able halves 110 , zipper 115 , and teeth 117 , hinge 120 , strap 130 , clip 140 , retaining cord 150 , removable hard inner liner 160 , mesh net pouch 170 and elastic lip 175 so that the container 10 and all components are washable. For example a material set can be chosen so that the container 10 and components can be put into a washing machine. Furthermore, the hinge 120 can be made from a number of materials. The hinge could be the same material as the outer zip-able halves 110 , a separate hinge assembly, a stretchable or expandable material, or a number of other implementations known to those skilled in the art.
There are a number of ways of protecting and containing oral appliances 180 with the embodiments described above. In one method, the user places the oral appliance 180 into the interior space 112 of the closable clam-shell like container 10 , and retains the oral appliance 180 inside the interior space 112 with the elastic retaining cord 150 . The user then closes the container 10 , and attaches the container to clothing or luggage with the strap 130 and clip 140 .
In another method the user places the oral appliance 180 in a remove-able hard inner liner 160 , and fits the liner 160 into the interior space 112 of the container 10 constraining both the oral appliance 180 and remove-able hard inner liner 160 inside the interior space 112 with the elastic retaining cord 150 .
In still another method of use, the user stores dental supplies or accessories of the oral appliance 180 in a pouch 170 attached inside the interior space 112 . The pouch 170 contains items inside the container interior 112 , while the elastic lip 175 keeps the items within the pouch 170 .
Some of the uses of the protective container for oral appliances 10 can also be described in flow chart form. In FIG. 13 the user begins by opening the protective container for oral appliances 10 at block 1010 . At block 1020 the user decides whether to use a liner for additional protection of the oral appliance 180 . If no additional protection is required the user retains the oral appliance 180 in the interior space 112 of the container with an elastic retaining cord 150 at block 1030 . If additional protection is required, the user places the oral appliance in a hard inner liner 160 and constrains both the oral appliance 180 and liner 160 in the interior space 112 of the container 10 with the elastic retaining cord 150 at blocks 1040 and 1050 . At 1060 the user decides if there are dental supplies or accessories needed for the oral appliance. If dental supplies or accessories are needed, the user stores them in the pouch 170 at block 1070 . At block 1080 , 1090 and 1100 , the user closes the container 10 , attaches it to clothing or luggage with the strap 130 and clip 140 , and transports the protected oral appliance 180 .
It will be appreciated that the invention is not limited to what has been described herein above merely by way of example. Although this invention has been described in terms of certain embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments that do not provide all of the features and advantages set forth herein, are also within the scope of this invention. While there have been described what are at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various other embodiments, changes, and modifications may be made therein without departing from the spirit or scope of this invention. Rather, the scope of the present invention is defined only by reference to the appended claims and equivalents thereof.
Reference Description/Alternate Terms 10 Container Clam shell like container Protective container for oral appliances 110 Outer zip-able cover Two container halves 112 Interior of outer zip-able cover Interior space Container interior 115 Zipper, Zipper Handle Closure 117 Zipper teeth 120 Hinge 130 Strap 140 Clip 150 Retaining cord Elastic retaining cord 152 Corners of cover halves 160 Removable hard inner liner Liner 164 Removable hard inner liner halves Clam shell like liner halves 165 Notch in hard inner container for retaining cord 150 168 Liner interior 170 Mesh net pouch Pouch 175 Elastic lip of mesh net pouch 180 Oral appliance 1010 Opening clam shell container 1030 Placing the oral appliance in a closable clam shell like container 1030 Retaining the oral appliance with an elastic retaining cord 1040 Placing the oral appliance in a liner 1050 Constraining the appliance and liner in the interior space w/cord 1070 Storing accessories in a pouch in the interior space 1090 Attaching the container to clothing or luggage 1100 Transporting oral appliance
Glossary of References Used in Figures
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A closeable clam shell type container with a retaining cord provides a protective enclosure for the storage and transport of oral appliances. A strap and clip allow the container to be attached to clothing and packs. Material choices allow versions that are machine washable. Some versions include a removable hard inner liner to provide further protection of oral appliances.
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BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to telephone-style modular jacks and, more particularly, is directed towards a cap member utilized in combination with such modular jacks.
II. Description of Related Art
Telephone-style modular plugs and jacks are well known. They are widely used as general interconnect devices for a variety of types of electrical equipment. As utilized herein, the terms "modular jack" and "modular plug" connote the miniature, interchangeable, quick-connect-and-disconnect jacks and plugs developed by Western Electric Company and Bell Telephone Laboratories originally for use with telephone equipment. See, for example, U.S. Pat. Nos. 3,699,498; 3,850,497; and 3,860,316.
Several modular jacks have been proposed for directly coupling a modular plug to a printed circuit board. See, for example, U.S. Pat. Nos. 4,210,376; 4,457,570; 4,501,464; 4,577,921; and 4,717,217.
In prior U.S. Pat. No. 4,457,570, assigned to the same assignee as the present application, there is described an improved modular jack whose principal feature is the provision of conductors which enter the plug-receiving cavity of the jack from the rear of the jack, rather than from the front of the jack as with previous designs. This feature results in substantial economies as a result of the reduction in required conductor length, and the like.
An improved version of this modular jack is set forth in copending application Ser. No. 07/827,878, filed Jan. 30, 1992, assigned to the same assignee as the present application, which is specifically incorporated herein by reference. Modular jacks as set forth in the cited copending application are manufactured and sold by Virginia Plastics Company, Inc. of Roanoke, Va., licensee of the present assignee, as, for example, MODCOM-C® Part No. 020.000.229.
The latter modular jack provides many advantages over parts previously available. For one thing, contact failure due to overstress is greatly reduced. The signal transfer surface area between the male and female conductors is optimized. Uniform contact resistance is obtained independently of the depth of insertion of the plug into the jack, and the likelihood of vibration-triggered open circuits is reduced. Finally, assembly and manufacturing are greatly simplified over prior designs. These improvements resulted from modifications to the housing and contact structure that are set forth in full in the referenced copending application, and which will be explained briefly hereinafter.
Despite the great improvement manifested by the MODCOM-C® connectors over the prior art, a few areas remain for further improvement. For example, while the configuration of the housing and conductors greatly minimizes overstressed contacts under normal use, the contacts can nevertheless be overstressed in situations where, for example, someone inserts an improper size of modular plug into the modular jack. Most frequently, the outer contacts of the jack are the ones which are caused to over extend upwardly into an overstressed condition.
Although overstressing the conductors is in and of itself not desirable, since thereafter the conductors may not operate with optimum contact pressure, there is another danger associated with overstressing these contacts. Namely, if stretched too far upwardly out of the housing, the contacts can touch the exposed surface of an adjacent panel or circuit board and produce an undesirable inadvertent electrical or ground connection.
Another situation which can occur in high voltage conditions is arcing across the jack cap and contacts. This is believed to result in part from an air gap that is created adjacent the contacts. It is also possible in such a situation for the jack cap to lift off the housing. It would be highly desirable if some means could be provided for minimizing high voltage arcing, and for keeping the jack cap in place on the housing.
It is towards overcoming the additional deficiencies noted above that the present invention is advanced.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a new and improved telephone-style modular jack which effectively prevents the spring contact portions of its conductors from over extending so as to touch adjacent electrical devices.
Another object of the present invention is to provide a new and improved telephonestyle modular jack which effectively insulates the spring contact portions of its conductors from inadvertently shorting to adjacent electrical devices.
A still further object of the present invention is to provide a new and improved modular jack which overcomes the above-noted deficiencies and which can be used in tight enclosures (e.g., a panel opening).
A still further object of the present invention is to provide a new and improved cap for a modular jack which reduces the possibility of high voltage arcing by minimizing the likelihood of creating an air gap around the jack cap.
Another object of the present invention is to provide a modular jack housing and cap structure that reduces the likelihood of the cap inadvertently lifting off of the housing.
The foregoing and other objects are attained in accordance with one aspect of the present invention through the provision of a telephone-type modular jack of the type that connects a telephone-type modular plug with a printed circuit board. The jack comprises a housing having a front portion, a rear portion, an upper outer wall, an opening formed in the front portion of the housing for receiving the telephone-type modular plug having a cord terminated by a plurality of side-by-side, substantially planar contact terminals, the contact terminals including a substantially flat, elongated upper edge surface. The jack further includes a plurality of electrical conductors arranged in a side-by-side, spaced apart fashion in the housing. Each of the conductors includes an end portion extending normally from the rear portion of the housing for insertion through a corresponding hole formed in the printed circuit board. A spring contact portion extends into the opening from the rear portion of the housing towards the front portion of the housing and includes a substantially linear lower portion, and an intermediate portion formed between the end portion and the spring contact portion. The upper edge surface of the contact terminals of the plug engage the linear portion of the spring contact portion of the conductors, causing the spring contact portions to be pivoted upwardly about a fulcrum point upon insertion of the telephone-type modular plug into the opening of the telephone-type modular jack. Finally, in accordance with the present invention, means are preferably provided for limiting the upward movement of the spring contact portions of the conductors.
The means for limiting the upward movement of the spring contact portions of the conductors comprises a separable cap member having a main body portion and bearing means positioned in contact with the intermediate portion of the conductors for defining the fulcrum point for the spring contact portions positioned forwardly of the fulcrum point.
In accordance with other aspects of the present invention, the separable cap member preferably includes cover means extending from the main body portion over the spring contact portions of the conductors for covering same. The separable cap member also preferably includes means for securing it to the housing. The bearing means is generally located on the underside of the cap member, while the cover means extends forwardly from the main body portion. More particularly, the cover means extends integrally from and is flexibly secured to the main body portion of the separable cap member.
The cover means flexes upwardly in response to pressure on its undersurface from the spring contact portions of the conductors. The cover means is preferably substantially rectangular and covers substantially the entire opening above the spring contact portions of the conductors.
In accordance with yet another aspect of the present invention, the means for limiting upward movement of the spring contact portions also preferably includes means for insulating the spring contact portions from touching other electrical devices.
In accordance with yet other aspects of the present invention, the separable cap member more particularly includes a forward edge and lateral edges. The means for securing the cap member to the housing preferably comprises means formed along the lateral edges of the cap member for interfacing with complimentary means formed in the housing of the modular jack. The means formed along the lateral edges of the cap member in one embodiment comprises a stairstep configuration; in another embodiment comprises a wedge-shaped configuration; and in yet a third embodiment comprises a step and reverse-wedge configuration. Such configurations also help prevent high voltage arching in the jack by inhibiting formation of an air gap in the cap.
In accordance with a further aspect of the present invention, there is provided a modular, telephone-type electrical connector comprising a modular jack that is characterized by a housing and a plurality of conductors arranged side-by-side in the housing. Each conductor includes a printed circuit matable portion and a spring contact matable portion for mating with the modular plug. The spring contact portion extends into the housing from the rear to the front, and is adapted to move upwardly in a direction out of the housing upon insertion of a modular plug into the housing. Finally, removable cover means for insulating the spring contact portions of the conductors from touching other components when moving upwardly out of the housing are provided. This removable cover means also inherently includes means for limiting the upward movement of the spring contact portions. The removable cover means preferably comprises a relatively thin, flexible cover portion that overlies the spring contact portions and includes lateral sides for lockably seating the cover portion in the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects, features and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when considered in connection with the accompanying drawings, in which:
FIG. 1 is a top, perspective view of a prior art cap for a modular jack;
FIG. 2 is a side sectional view illustrating a modular plug inserted into a modular jack;
FIG. 3 is a top, perspective view illustrating a preferred embodiment of the present invention;
FIG. 4 is a longitudinal sectional view illustrating the preferred embodiment of the present invention installed;
FIG. 5 is a view similar to FIG. 4, but illustrating the present invention in an over stressed condition;
FIG. 6 is a view similar to FIG. 5, but showing how the present invention would operate in a panel opening or other tight enclosure;
FIG. 7 is a perspective view illustrating a preferred embodiment of the present invention;
FIG. 8 is a sectional view taken along line X--X of FIG. 7 illustrating a preferred embodiment of the present invention;
FIG. 9 is a sectional view taken along line X--X of FIG. 7 illustrating an alternate embodiment of the present invention;
FIG. 10 is a sectional view taken along line X--X of FIG. 7 illustrating yet another alternate embodiment of the present invention;
FIG. 11 is a perspective view illustrating still another alternate embodiment of the present invention;
FIG. 12 is a sectional view taken along line Y--Y of FIG. 11 showing an alternate embodiment of the present invention;
FIG. 13 is a sectional view taken along line Y--Y of FIG. 11 showing an alternate embodiment of the present invention; and
FIG. 14 is a sectional view taken along line Y--Y of FIG. 11 showing yet another alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein like reference numerals represent identical or corresponding parts throughtout the several views, and more particularly to FIGS. 1 and 2 thereof, there is illustrated what is essentially a modular plug, modular jack, and modular jack cap of the prior art.
More particularly, referring first to FIG. 2, there is illustrated a typical modular jack which is indicated generally by reference numeral 26. Modular jack 26 is an improved version of the type set forth in prior U.S. Pat. No. 4,457,570, assigned to the same assignee as the present invention. The improvements represented by modular jack 26 are shown and described in greater detail in co-pending utility patent application Ser. No. 07/827,878, filed Jan. 30, 1992, which is specifically incorporated herein by reference, and which is also assigned to the same assignee as the present invention. These modular jacks are marketed by Virginia Plastics Company Inc., licensee of the present assignee, under the trademark MODCOM-C® (e.g., Part No. 020.000.229).
In particular, modular jack 26 is designed to be mounted directly onto a printed circuit board (PCB) (not shown) by means of mounting feet 28. The PCB normally includes an alternating, staggered hole arrangement for receiving the perpendicularly extending end portions 40 of conductors 42 of jack 26, which will be described in greater detail hereinafter.
As set forth in the co-pending application referenced above, modular jack 26 comprises a unipartite dielectric housing 26 having a separable cap member indicated generally by reference numeral 10.
Referring back to FIG. 1, cap member 10 comprises a substantially rectangular top portion 12 having a pair of shoulders 14 and 16 extending laterally therefrom. The front portion of rectangular top 12 is defined by a leading edge 22. Extending downwardly from shoulders 14 and 16 are a pair of retaining wedges 18 and 20 which are designed to snap-fit into apertures formed in the housing of modular jack 26, all in a manner fully described in the co-pending application referenced above.
Cap 10 also includes on its underside a bearing portion 13 (FIG. 2) which covers the intermediate portions 64 of conductors 42. Bearing portion 13 includes a front face or edge 15 which defines a fulcrum point for the spring contact portions 62 of conductors 42, again in a manner which will be described in greater detail below.
Modular jack 26 includes a top outer wall 32, a front wall 34, and a plug-receiving cavity or opening 36 in which is shown inserted a mating modular plug 30 of conventional construction.
In particular, modular plug 30 comprises a dielectric housing 38 in one end of which is formed a cord-input end 44 for receiving a multi-conductor cord or cable (not shown). Characteristically, a resilient locking tab 46 extends downwardly and rearwardly from the front portion of housing 38. Locking tab 46 cooperates with spaced shoulders (not shown) of housing 26 to secure plug 30 in place, as is well known. Positioned within a plurality of side-by-side slots formed in the front upper part of housing 38 are a plurality of substantially flat, conductive contact terminals 50. Each of the contact terminals 50 includes a pair of downwardly extending, insulation-piercing tangs 52. The upper boundary of contact terminal 50 preferably comprises a flat edge surface 54 which is adapted to electrically contact the spring contact portion 62 of conductors 42 of jack 26, in a manner to be described. Finally, plug 30 characteristically includes a retaining bar 56 which may be rotated from the position illustrated so as to engage the cable inserted into opening 44 so as to provide strain relief, all of which is quite well known in the art.
Returning now to the structure of modular jack 26, it characteristically includes a plurality of side-by-slots 58 extending to the top outer wall 32. Slots 58 are adapted to receive and align the forward spring contact portions 62 of a plurality of side-by-side conductors 42 which are arranged in housing 26. Each slot may be seen to include a lip 60 that extends rearwardly from forward wall 34 and upon which the end of spring contact portion 62 is designed to rest during repose.
As heretofore explained, each of the conductors 42 includes a solder-post portion 40, a spring contact portion 62, and an intermediate portion 64 extending between portions 40 and 62.
More particularly, spring contact portion 62 includes a moment arm 66 which uses the forward edge 15 of jack cap 10 as a fulcrum. Spring contact also includes a lower surface 68 which is adapted to contact the upper edge surface 54 of contact terminal 50, and an end portion 70 which, as explained above, rests on lip 60 during repose.
In FIG. 2, the spring contact portion 62 of conductor 42 is illustrated in a slightly overstressed condition, which can be caused, for example, by inserting an oversized plug into plug-receiving cavity 36. The over-stressed condition of spring contact portion 62 is characterized by the fact that end portion 70 extends upwardly above top outer wall 32 of housing 26, as shown in FIG. 2. In this situation, the danger is that the end portion 70 will contact another electrical device or component positioned adjacent housing 26 to cause an electrical malfunction. Another danger is that a barrier will be presented in close juxtaposition to housing 26, against which end portion 70 will bear, thereby possibly malforming the remaining portion of spring contact 62, leading to a malfunctioning of the jack. The difficulty is that, with the exception of forward edge 17 of cap 10, there is no restraint on the upward movement of spring contact portion 62 in an over-stressed condition, and electrical malfunction or jack failure may result. In addition, the space above the spring contacts 62 is open, creating a large air gap that, in a high voltage environment, tends to encourage undesirable arcing.
In accordance with the present invention, these difficulties are substantially alleviated by the provision of an improved jack cap which is indicated generally by reference numeral 80 in FIG. 3, and which is shown in proper position on a modular jack in FIGS. 4 and 7.
Referring first to FIG. 3, cap 80 of the present invention comprises a main body portion 81 which consists essentially of a rectangular top portion 12 substantially identical to that of the prior art jack cap 10. In addition, extending laterally from top portion 12 in this embodiment are a pair of shoulders 14 and 16, just as with the prior design, from which extend downwardly a pair of interlocking wedges 18 (not shown in this view) and 20.
In accordance with the present invention, extending forwardly from leading edge 22 of rectangular top portion 12 is an extended top wall portion 82. Top wall portion 82 of the present invention is preferably integrally formed with the remainder of cap 80, and is on the order of 0.020 inch thick. It is defined by a front edge 88 and side edges 84 and 86.
Referring now to FIG. 7, there is illustrated a perspective view of modular jack 26, but without any modular plug inserted into plug-receiving opening 36. Also, the cap 80 of the present invention is illustrated installed onto modular jack housing 26. It may be appreciated that the leading edge 88 and side edges 84 and 86 fit within the surrounding frame of top wall 32 of jack housing 26 so as to cover and provide a substantial enclosure for the spring contact portions 62 and other components under the extended top wall portion 82. This greatly reduces the likelihood of high voltage arcing over prior art designs.
Referring back to FIG. 4, the cap 80 is also seen to include on its underside a bearing surface 83 which, similar to bearing surface 15 of cap 10 of FIG. 2, defines a fulcrum for the spring contact portion 62.
The relative position of the elements illustrated in FIG. 4 are that spring contact portion 62 is shown mating properly with contact terminal 50. In this condition, end portion 70 is slightly raised off lip 60, and either does not touch or merely touches slightly the underside 85 of extended top wall portion 82 of cap 80.
In general, an over-stressed condition of spring contact portions 62 can occur in one of two instances: these instances are illustrated respectively in FIGS. 5 and 6. Referring first to FIG. 5, the first instance occurs when, for example, a modular plug of the wrong size is inserted into modular jack 26 (this instance is also shown in FIG. 2). With the present invention as illustrated in FIG. 5, as the end portion 70 presses against the bottom surface 85 of extended top wall portion 82, the latter flexes slightly upwardly, as shown. In this manner, the extended top wall portion 82 provides a dielectric barrier between spring contact portion 62 and whatever electrical components may surround the jack housing 26. This prevents spring contact portion 62 and particularly end portion 70 from inadvertently engaging other electrical devices. When the over-stressed condition is removed, spring contact portions 62 lower to their normal position, as does the extended top portion 82 of cap 80.
The other over-stressed condition is exemplified by FIG. 6, wherein modular jack 26 is shown mounted in a very tight enclosure such as in a panel opening represented by upper and lower partition walls 90 and 92, respectively. In an over-stressed condition, bottom wall 85 of extended top portion 82 is also engaged by end portion 70 of spring contact portion 62. However, the extended top wall portion 82 either cannot move upwardly at all, or can move only a very limited amount vertically before it engages the lower edge 94 of upper partition wall 90. In such a situation, upon further upward flexing of spring contact portion 62, the latter will flex longitudinally (in essence, stretch out). When the offending plug is removed, spring contacts 62 return to their normal position, as does extended top wall portion 82 of cap 80 of the present invention, if it has moved at all. As with the first condition, top wall portion 82 serves to prevent spring contacts 62, and particularly end portions 70 thereof, from engaging other adjacent devices by serving as a dielectric and physical barrier.
Referring now to FIG. 8, there is illustrated one possible embodiment for the interface between the side edges 84 and 86 of jack cap 80 and the surrounding top wall 32 of modular jack 26. In this embodiment, the interface comprises a stairstep configuration indicated generally by reference numeral 100. This stairstep configuration 100 is defined by a first step 96 and a second step 98 formed on the underside of side edges 84 and 86 of extended top wall portion 82. Stairsteps 96 and 98 have complimentary steps, of course, formed in the adjacent sides of top wall 32 of housing 26 so as to mate therewith. This stairstep configuration has the advantage of making it more difficult in a high voltage application for arcing to occur by reducing the possibility of a line-of-sight air gap forming. Yet, in this embodiment, top wall portion 82 is still free to flex upwardly, absent a tight enclosure.
Referring now to FIG. 9, there is illustrated an alternate embodiment wherein the interface is defined by a V-shaped wedge indicated generally by reference numeral 110. Wedge 110 is defined by a lateral bottom surface 112 and an inclined surface 114 that is preferably formed at an acute angle to bottom surface 112 so as to define a sharp tip or edge 116. V-shaped wedge 110 is designed to mate with a complimentary formed recess extending along the side frames of top wall 32 of jack 26. This particular embodiment may be snap-fit into place. In addition to inhibiting high-voltage arcing by closing the air gap, the interlock provided by the V-shaped wedge 110 helps prevent cap 80 from lifting off jack housing 26.
FIG. 10 illustrates yet another alternate embodiment which combines the step function of FIG. 8 with the wedge function of FIG. 9, albeit in an inverted configuration. More particularly, the step and reverse-wedge interface 120 includes a bottom horizontal surface 122, an angled side surface 124, and a stepped surface 126. This configuration acts to form a lip 35 in the side frames of top wall 32 of housing 26 for interlocking with the step and reverse-wedge 120. This embodiment also inhibits high voltage arcing and substantially inhibits lifting of jack cap 80. This configuration may also be snap-fit into place.
Since the side edges 84 and 86 of extended top wall portion 82 of the embodiments of FIGS. 9 and 10 are effectively secured, there is no upward movement (except perhaps for some central bowing) of top wall portion 82 in an overstressed condition. Thus, these embodiments operate in a manner analogous to that of FIG. 6 where upward movement of top wall portion 82 is limited.
FIGS. 11-14 illustrate an alternate embodiment of the jack cap 130 of the present invention which eliminates the shoulders 14 and 16 of the previous embodiments. In this manner, the jack cap 130 may be slid into the side frames of the top wall 32 of modular jack housing 26' from the rear, rather than being snap-fit into place as with FIGS. 7-10. The jack cap 130 of FIG. 11 includes therefore straight lateral sides 132 and 134, a rear portion 136, and a forward portion 138 which covers the spring contact portions of jack 26'.
FIGS. 12, 13 and 14 are similar to the embodiments of FIGS. 8, 9 and 10 in that they employ similar interfaces between the jack cap and the top wall of the modular jack housing; however, FIGS. 12-14 employ the "shoulderless" embodiment of FIG. 11.
More particularly, FIG. 12 illustrates the jack cap 130 with a stairstep interface 140, FIG. 13 illustrates jack cap 130 with a wedge interface 150, and FIG. 14 illustrates jack cap 130 with a step and reverse-wedge interface 160.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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A new and improved modular jack which employs a unique jack cap that prevents accidental electrical malfunctions when the conductors of the modular jack are in an overstressed condition. The jack cap also features means for inhibiting high voltage arcing, and for securing the cap to the jack housing even under such extreme conditions.
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BACKGROUND OF THE INVENTION
The present invention generally relates to the extrusion polyolefins, particularly low density polyethylene, linear low density polyethylene and high molecular weight, high density polyethylene resins in the form of film, especially blown or cast film or sheet.
Linear low density polyethylene (LLDPE) resins were introduced in the U.S. market recently and have had a substantial impact on industry. The mechanical properties of LLDPE provide superior performance, in terms of strength and puncture resistance, which results in thinner films useful in a variety of applications and have resulted in the opening of new markets.
LLDPE, due to its unique molecular structure and resulting rheology, has created special problems in processing. These problems include the net reduction of throughput due to the high horsepower required to process a kilogram of polymer and the requirement for more torque than is available for most blown film drives to maintain equivalent throughput. Since more torque is needed to extrude LLDPE, extruders are pushed to the limits of their capabilities and the resulting melt temperature is higher than desired for extruding blown film. The higher melt viscosity and higher temperatures are detrimental to the machinery and to the end product.
To maintain throughput, modification of equipment, modification of the resin and the use of higher temperatures, or a combination thereof, are required. Higher torque, higher temperatures and higher pressures have detrimental effects the properties of the final products, including the phenomenon of sharkskin melt fracture, i.e., surface roughness of the film. Sharkskin is largely a result of high melt temperature from frictional heat generated by higher extrusion torques.
The extrusion of LLDPE requires substantially higher power for processing than low density polyethylene (LDPE). In addition, high and ultra high molecular weight, high density polyethylene (HDPE) require additional power to extrude and their torque requirements can be double that of LDPE. Most extruder drives do not have the capability of generating such high torque and, therefore, extrusion throughput is sacrificed to accommodate the higher torque requirement.
The reduction in screw speed which is necessary to compensate for mechanical overloading of the extruder and its critical components, such as gear box and thrust bearings, creates yet another major problem for the film processor. The rotational speed of the screw in the extruder is a function of drive power; reduction in screw speed as a result of lower torque results in lower throughput.
Throughput studies indicate that a conventional LDPE extruder which would normally handle a 2.0 melt index (MI) LDPE, suffers a 27% loss in throughput when a 1.0 MI LLDPE is processed.
The loss of throughput has created a market for the manufacturers of machinery and equipment capable of extruding LLDPE without throughput loss. Many screw designs have been suggested and evaluated. In fact, the so-called "short screws" are being used in applications where LDPE blown film extruders have been retrofitted for blown LLDPE film production. These modifications of existing machinery or purchases of new generation extruders involve large sums of capital. In the majority of cases, such an investment is impractical.
Present manufacturers are also trying to change the processing requirements of LLDPE resins by modification of resin technology.
Another approach is to blend LLDPE with LDPE resins. Such blending to increase production and ease processing requirements has partially solved some of the problems associated with the extrusion of LLDPE resins. Depending upon the ratio of LDPE to LLDPE in the blend, the properties of the blended resin film are substantially different from that of unmodified LLDPE film as evidenced by inferior draw-down capabilities and other physical properties.
LLDPE film exhibits superior tensile strength, tear strength, draw-down characteristics, stiffness and puncture resistance. These properties, however, will dramatically deteriorate as the level of LDPE in the blend increases. The two most important properties of LLDPE, film tear resistance and puncture resistance, will decrease considerably with the increase of LDPE in the blend.
Accordingly, it is an object of the present invention to provide a processing aid composition which is blended with polyolefins, especially with LLDPE or LDPE, or blends thereof, or HDPE resins or blends thereof to afford increased extrusion throughput by altering the rheology of the resins, thereby resulting in higher screw speeds, lower head pressures, reduced power consumption, lower torque and lower processing temperatures while maintaining throughput.
Additionally, it is an object of the present invention to provide a composition comprising a polyolefin or polyolefin blends, particularly LLDPE or LDPE resins, or blends thereof, or HDPE and blends thereof and a processing aid composition therefore.
Further, it is an object of the present invention to provide a process for extruding polyolefins such as LLDPE, LDPE or HDPE and blends thereof which comprises adding to said polyolefin, prior to extrusion, a processing aid composition as described herein.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a processing aid composition which is blended with polyolefin resins, such as polyethylene, polypropylene, polybutylene and blends thereof and the like, in order to increase extrusion throughput while allowing moderate processing conditions and lower equipment stress.
The processing aid composition of the present invention is comprised as follows:
(a) an amide of a saturated or unsaturated carboxylic acid or an alkylene bisamide of a saturated or unsaturated dicarboxyllic acid; (b) an aliphatic hydrocarbon polymer or mixture thereof having a number average molecular weight of from about 400 to about 50,000; and (c) an oxygen-containing HDPE having an average molecular weight of from about 1,000 to about 3,000.
DETAILED DESCRIPTION OF THE INVENTION
As described above, the processing aid of the present invention comprises (a) an amide of a saturated or unsaturated carboxylic acid, especially a monocarboxylic acid, or an alkylene bis-amide of a saturated or unsaturated dicarboxylic acid, (b) an aliphatic hydrocarbon polymer or mixture thereof having a number average molecular weight from about 400 to 50,000 and (c) an oxygen-containing low molecular weight HDPE.
The amides which have been found useful in accordance with the present invention include primary amides of carboxylic acids having from about 12 to about 22 carbon atoms. Thus, for example, there may be used amides of lauric, myristic, palmitic and stearic acids as well as diamides of acids such as oxalic and adipic acids and amides of unsaturated acids such as oleic and erucic acids.
The alkylene bis-amides which have been found useful in accordance with the present invention generally have the structure. ##STR1## wherein R' represents alkyl having from about 2 to about 5 carbon atoms and R represents an alkylene group of from about 12 to about 22 carbon atoms. Illustrative alkylene bis-amides include, but are not limited to, ethylene bis-stearamide, ethylene bis-palmamide, propylene bis-stearamide, propylene bis-oleamide and the like.
The processing aid composition additionally comprises aliphatic hydrocarbons and mixtures thereof having an average molecular weight (vapor pressure osmometer) of from about 400 to about 50,000, preferably from about 600 to about 35,000, especially from about 600 to about 25,000. Examples of such hydrocarbon materials include, but are not limited to, petroleum waxes, including high melting point paraffin waxes, microcrystalline waxes, tank bottoms and the like, synthetic waxes such as α-olefin, Fischer-Tropsch and amide waxes, low molecular weight polyethylene and reactive waxes, e.g., ester waxes, and the like.
A third component of the processing aid composition of the invention comprises an oxygen-containing, high-density polyethylene having an average molecular weight (vapor pressure osmometer) of from about 1,000 to about 3,000, preferably from about 1,200 to about 1,700, with an acid number of from about 10 to about 30, preferably from about 15 to about 25. This component may be prepared by free radical oxidation of polyethylene, by copolymerization of ethylene with an oxygen-containing monomer such as vinyl acetate or by graft polymerization of polyethylene with an oxygen-containing monomer, e.g., acrylic acid or maleic anhydride, or polymer.
The above described processing aid composition is blended with a polyolefin, e.g., LLDPE, LDPE or HDPE resins or blends thereof in solid form (e.g., prills, pellets) at a level of from about 0.005 to about 8% by weight, preferably from about 0.05 to about 6% by weight, especially from about 1 to about 4% by weight.
Although the processing aid of the present invention may be used in a wide variety of particle sizes, ranging from micronized powder to pellets, for ease of blending and for maximum efficiency the particle size of the processing aid and the particle size of the polyolefin with which it is blended should be matched as closely as possible. The most efficient blending results from a blend of powdered processing aid and powdered polyolefin resin. The processing aid may also be added to the polyolefin in an extruder in liquid, i.e., molten, form.
The processing aid may be added to the polyolefin in a master blending operation and the master batch then fed to the extruder or the processing aid may be added to the polyolefin by conveyor feeding or auger feeding at an appropriate zone of the extruder.
The polyolefin resins to which the processing aid is added, e.g., polyethylenes, polypropylenes, polybutylenes and the like and blends thereof, may contain customary formulating additives such as fillers, e.g., carbon black, titanium dioxide, calcium carbonate, talc, mica, clays and other additives such as colorants, pigments, plasticizers, impact modifiers and the like.
The processing aid composition, depending on the nature of the polyolefin resin, comprises from about 0 to about 6% amide, from about 86 to about 100% aliphatic hydrocarbon mixture and from about 0 to about 8% oxidized, low molecular weight HDPE.
The following examples illustrate specific embodiments of the invention, including the best means for practicing the invention, but it is understood that the examples are illustrative only and the invention is not to be limited thereby.
EXAMPLE 1
This example illustrates the preparation of a typical processing aid composition of the present invention.
In a mild steel reactor, equipped with heater and a mixing blade, there were blended 2500 gms. of a composition comprising 3% by weight ethylene bis-stearamide, 94% by weight of a mixture of aliphatic hydrocarbon polymers having a number average molecular weight of about 850 and 3% by weight of low molecular weight, oxidized HDPE. The materials were blended under mild agitation for 15 minutes at 150° C.
Typical properties of the processing aid composition of the invention are:
______________________________________PROPERTY TEST METHOD UNITS______________________________________Softening Point ASTM D-36 112.8° C.Viscosity @ 121° C. ASTM D-3236 21 cpsColor ASTM D-1500 0.5Flash Point ASTM D-92 296° C.Density ASTM D-1505 0.93 gm/ccAcid Number BWM 3.01 AT 1.5 mg KOH/gmFDA Status Indirect Food Additive Passes______________________________________
It is to be understood that other acid amides, as described above, should function in a manner equivalent to ethylene bis-stearamide. Thus, it is contemplated that, for example, lauramide, stearamide, oxalamide, adipamide, oleamide and erucamide may be used in lieu of ethylene bis-stearamide in the above and following examples.
EXAMPLE 2
This example illustrates the preparation of a typical processing aid composition of the present invention. In a simple blender equipped with mixing blades, there was blended 2500 grams of a composition comprising 0.9% by weight ethylene bis-stearamide, 98.2% by weight of a mixture of aliphatic hydrocarbon polymers having a number average molecule weight of about 21,000 and 0.9% by weight of low molecular weight, oxidized HDPE. The materials was blended for 15 minutes at room temperature and was extruded in a 19 mm extruder at 105° C. into a single strand (4 mm diameter) and subsequently pelletized into pellet form.
Typical properties of the processing aid composition of the invention in Example 2 are:
______________________________________PROPERTY TEST METHOD UNITS______________________________________Softening Point ASTM D-36 230° F. (110° C.)Viscosity @ 175° C. ASTM D-3236 33000 CPSDensity ASTM D-1505 0.926 g/ccFlash Point ASTM D-92 495° F. (257° C.)______________________________________
EXAMPLE 3
This example illustrates extrusion data obtained when the processing aid composition of Example 1 was blended with HDPE. The data were developed using a 3/4 inch (19 mm.) Brabender extruder (25:1 L/D) with a 3:1 ratio with a 1/8 inch (3 mm.) rod die.
Temperature Profile:
Zone I 185° C.
Zone II 185° C.
Zone III 185° C.
Die 193° C.
TABLE I__________________________________________________________________________ TORQUE SCREWSPEED THROUGHPUT TORQUEMATERIAL (m. gm.) RPM gms/min % Increase CHANGE__________________________________________________________________________100% Gulf 9634 HDPE 1850 25 13.0 -- --1% Additive in Gulf 9634 1750 25 13.1 -- (5.4)1% Additive in Gulf 9634 1800 28 14.5 11.5 --2% Additive in Gulf 9634 1600 25 13.1 -- (13.5)2% Additive in Gulf 9634 1850 31 16.6 27.7 --__________________________________________________________________________
As indicated in the above data, the processing aid used at a level of 1% to 2% reduces the torque requirement by 5.4% to 13.5% when compared with virgin resins at the same screwspeed. However, when screwspeed was increased to 28 RPM and finally to 31 RPM to reach the torque of virgin resin (1850 m. gm.) throughput was increased from 11.5% (at 1% level) to 27.7% (at 2% level).
EXAMPLE 4
This example illustrates extrusion data obtained upon blending the processing aid composition of Example 1 with LLDPE.
TABLE II______________________________________LLDPE Extrusion DataDowlex 2045 LLDPE 43 RPM 43 RPM 63 RPM 100% Resin 98% Resin + 2% Additive______________________________________Throughput, Kg/hr 33 31 39Head Pressure, Kg/cm.sup.2 274 253 295Screwspeed, RPM 43 43 63Amperage 43 37 43Volts 160 160 230Melt Temperature °C. 246 246 252Throughput Change -- (5.5%) 18.1%______________________________________
As shown by the above data, at 2% level, the processing aid increased throughput by 18.1% at the same amperage.
EXAMPLE 5
This example further illustrates extrusion data when the processing aid composition of Example 1 was blended with LLDPE.
TABLE III______________________________________Exxon LPX 2.09 LLDPE 43 RPM 43 RPM 53 RPM 100% Resin 98% Resin + 2% Additive______________________________________Throughput, Kg/hr 31 29 35Head Pressure, Kg/cm.sup.2 222 211 225Screwspeed, RPM 43 43 53Amperage 36 32 36Volts 160 160 195Melt Temperature °C. 232 232 232Throughput Change -- (5.9%) 12.9%______________________________________
Extruder: 64 mm. single stage
24:1 L/D with 203 mm. die
Temperature profile:
Barrel (all 4 zones) 204°-221° C.
Die 204°-221° C.
Screen Pack 30-60-30
EXAMPLE 6
This example further illustrates extrusion data of a blend of the processing aid composition of Example 1 with LLDPE.
TABLE IV______________________________________Exxon LPX 1.09 LLDPE 41 RPM 41 RPM 58 RPM 80% LLDPE/20% LDPE + 2% Additive______________________________________Throughput, Kg/hr 62 59 75Head Pressure, Kg/cm.sup.2 422 369 408Screwspeed, RPM 41 41 58Amperage 148 115 142Throughput Change -- (4.5%) 21.0%______________________________________
Extruder: 102 mm. dual head
24:1 L/D with 203 mm. die
Temperature profile:
Barrel (all zones) 225°-235° C.
Die 230°-237° C.
In Tables II-IV, note that the amperage (2nd column) has been reduced substantially, thereby reducing the load on the extruder while only a minor reduction in throughput is effected. In the 3rd column, amperage has been raised to the level of the amperage of the 1st column, thereby increasing throughput at the same load level.
EXAMPLE 7
This example illustrates extrusion results comparing the reduction in torque achieved using the processing aid of Example 1 compared with use of a mixture of hydrocarbons having an average molecular weight of about 850. The data were developed using a 19 mm. Brabender extruder (L/D-25:1) with a 3:1 ratio and a 3 mm. rod die.
Temperature Profile:
Zone 1 185° C.
Zone 2 190° C.
Zone 3 190° C.
Die 190° C.
Melt Temp. 211° C.
TABLE V______________________________________ SCREW SPEED TORQUE % REDUCTIONMATERIAL (RPM) (m. gm.) in TORQUE______________________________________LLDPE 25 1800 --LLDPE + 25 1650 8.32% HydrocarbonLLDPE 25 1750 --LLDPE + 25 1600 9.92% Processing Aid______________________________________
As the data illustrate, the processing aid composition was more effective than the mixture of hydrocarbons.
EXAMPLE 8
This example illustrates extrusion results of LLDPE using a Fischer-Tropsch hydrocarbon (known as Sasol Paraflint H-1).
The data were developed using a 19 mm Brabender extruder (25:1 L/D) with a 3:1 comparison ratio and a 3 mm rod die temperature profile:
Zone 1 185° C.
Zone 2 190° C.
Zone 3 190° C.
Die 190° C.
Melt temperature 212° C.
TABLE VI______________________________________ SCREW SPEED TORQUE % REDUCTION INMATERIAL (RPM) (M. Gm) TORQUE______________________________________LLDPE* 25 1650 --LLDPE + 2% 25 1450 12Fischer-Tropsch______________________________________ *LLDPE used in this experiment is a mixture of 50 parts LLDPE and 50 part LDPE.
EXAMPLE 9
This example further illustrates extrusion data of a blend of the processing aid composition of EXAMPLE 2 with LLDPE resin.
______________________________________Extruder: 4.5 inch Egan Die: 24 inch 30:1 (L/D) Gap: 35/1000______________________________________Extrusion Data Dowlex 2045 72 RPM 82 RPM 72 RPM 98% Resin + 100% Resin 2% Processing Aid______________________________________Throughput, Kg/h 220 218 250Head Pressure, Kg/Cm.sup.2 302 288 309Screw Speed, RPM 72 72 82Amperage 197 182 197Melt Temperature °C. 224 224 235Throughput change -- (0.8%) 13.6%______________________________________
As shown by the above data, at 2% level the processing aid increased the throughput by 13.6% at the same amperage.
It is contemplated that other polyolefins, such as polypropylene, polybutylene and blends thereof with each other and with polyethylene, would show similar results in the above examples.
While the illustrative embodiments of the invention have been described here and above with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and description set forth herein but rather that the claims be construed as encompassing all of the features of patentable novelty which reside herein, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains.
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There is disclosed an extrusion processing aid composition for the extrusion of polyolefins, particularly linear low density polyethylene and high density polyethylene films or sheets; polyolefin compositions containing said processing aid and a process of extruding polyolefins using said processing aid. The processing aid is a composition comprising (a) an amide of a saturated or unsaturated carboxylic acid or a saturated or unsaturated alkylene bis-amide of a saturated or unsaturated dicarboxylic acid; (b) an aliphatic hydrocarbon polymer mixture having a molecular weight of from about 400 to about 50,000; and (c) an oxygen-containing high density, low molecular weight ethylene polymer.
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This is a continuation of copending application Ser. No. 07/594,123, filed on Oct. 9, 1990, now abandoned, which is a continuation-in-part of application Ser. No. 07/396,365, filed on Aug. 21, 1989, now abondoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to an improved orthopedic device for lower back support during work, exercise, and competition.
2. Description of the Prior Art
Exercise and weight training belts are used to provide lower back support to avoid injury to this area when under stress from activity. The range of use of these devices is broader than generally thought. For example, truck drivers use them on extended trips, and construction workers use them when lifting heavy loads on the job. Regardless of the reasons for use, currently there is no belt that properly addresses the most sensitive area of the back, the lumbar region ---- that is, the area of the lumbar vertabrae and surrounding erector muscles down to the small of the back. Devices of the prior art are belts whose construction provides for support along its horizontal center with support diminishing as a person moves above or below this center. At the lumbar region, these devices bridge across the spine via the erector muscles, leaving a gap at the center of the back.
More particularly, conventional orthopedic devices do not afford balanced, equal, and uninterrupted support to the lumbar region along the entire horizontal and vertical planes thereof.
The first part of the problem is to supply uninterrupted support across the back along the horizontal plane. The problem arises because conventional belts are of flat, single level construction. Some belts have lumbar pads, but these pads are also flat or of one piece construction. The back, across the lumbar area, is indented and curved. The erector muscles are indented from the flat of the back, and the spine is further indented at the center of the back. Thus, belts of flat construction can not provide even, uninterrupted support in the horizontal plane.
The second part of the problem is to supply equal support or pressure uniformly from the top to the bottom of the belt along the vertical plane. Conventional belts are constructed in one of three basic ways: single unit with a single fastener, single units with dual fasteners, and two part construction ---- i.e., a wide body with a narrow support belt affixed with a fastener. The single unit belts with one fastener and the two part construction belts tend to concentrate the support pressure along the horizontal center of the belt. This support decreases to almost zero at the upper and lower edges of the belt. The single unit-dual fastener construction belts have the problem of the upper and lower edges of the belt digging into the back of the wearer and the center of the belt bowing outwardly, thereby giving unequal support in the vertical plane.
Accordingly, it is an object of the present invention to provide an orthopedic device affording balanced, equal, and uninterrupted support to the lumbar region along the entire horizontal and vertical planes thereof.
Another object is to provide such a device which is of simple and rugged construction and economical to manufacture, use and maintain.
SUMMARY OF THE INVENTION
It has now been found that the above and related objects are obtained in an orthopedic device, to provide lower back support for a wearer, according to the present invention. The device comprises a flexible flat body, a resilient contoured lumbar support pad of varying thickness secured to said body, and a flexible belt traversing the pad and secured to the body at points beyond the pad, the belt being configured and dimensioned to be secured about the waist of the wearer for positioning the pad on the lumbar of the wearer.
In a preferred embodiment, the body is of one-piece, integral, unitary construction and has a pair of opposed faces, the pad being secured to the face adjacent the wearer, when worn, and the belt being secured to the opposite face. The pad comprises a plurality of articulated sections including a center section of at least a first thickness adapted to be positioned over the spine of the wearer and wide enough to bridge the gap at the spine between the erector muscles of the wearer, and at least one side section of a second thickness disposed on each side of the center section and adapted to be positioned adjacent the erector muscles of the wearer, the first thickness being substantially greater than the second thickness. The center section has a thickness along its central vertical axis which is greater than its thickness to either side. The pad extends substantially from the top of the belt to the bottom of the belt, and preferably substantially from the top of the body to the bottom of the body, thereby to provide support at the lumbar of the wearer across the width of the device.
In one preferred embodiment, the belt consists essentially of two vertically spaced straps secured to the body in parallel disposition and releasable fastener means secured thereto for securing the ends of each strap independently about the wearer's waist. The pair of straps optimally trisect the height of the body.
In another preferred embodiment, the belt consists essentially of a single strap and releasable fastener means secured thereto for securing the belt about the wearer's waist. The strap is preferably secured to the body in a generally elliptical configuration, the strap having one end secured to a first point at the center of one end of the body, extending in an upward arc, with the apex of the upward arc near the upper edge of the middle of the body, and descending to a second point at the center of the opposite end of the body, where the strap forms a loop extending beyond the opposite body end and is secured to the second point. The strap also extends from the second point in a downward arc, with the nadir of the downward arc near the lower edge of the middle of the body opposite the apex, and rises to cross-join and overlap the strap one end at the first point, thereby to complete the generally elliptical configuration. Finally the strap extends beyond the one body end to form a tongue for fastening. The fastener means is preferably a tape fastener system affixed to the outside face of the tongue and includes a fastener frame defining a slot, the loop of the strap extending through the slot.
The device of the present invention provides uninterrupted support across the back along the horizontal plane due to the multilevel and articulated configuration of the pad providing three levels of construction; in addition to the general flat level of the body of the device, there are the two additional levels of the contoured lumbar pad. This construction enables the device to fit more uniformly across the back, providing uninterrupted support. The device of the present invention provides equal support or pressure uniformly from the top to the bottom of the belt along the vertical plane due to its use of the body as a platform for mounting either a single elliptical strap system or two separate parallel straps vertically spaced so as to distribute pressure uniformly throughout the width of the belt in the lumbar region.
The present invention also encompasses an orthopedic device to provide lower back support for a wearer, comprising a resilient contoured lumbar support pad of varying thickness having a pair of opposed ends and a flexible belt traversing the pad and operatively secured thereto adjacent the opposed pad ends, the belt being configured and dimensioned to be secured about the waist of the wearer for positioning the pad on the lumbar region of the wearer.
BRIEF DESCRIPTION OF THE DRAWING
The above brief description, as well as further objects and features of the present invention, will be more fully understood by reference to the following detailed description of the presently preferred, albeit illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawing wherein:
FIG. 1a is an isometric view showing an embodiment of the lumbar support pad on the single fastener belt;
FIG. 1b is an isometric view showing an embodiment of the lumbar support pad on the dual fastener belt;
FIG. 2 is a sectional plan view of the lumbar area, with the belt worn around the user's waist, looking down;
FIG. 3a is a fragmentary rear elevational view of the single elliptical strap-single fastener embodiment;
FIG. 3b is a fragmentary rear elevational view of the dual strap support-dual fastener embodiment;
FIG. 4 is a schematic view showing the various steps in the manufacture of the lumbar support pad; and.
FIG. 5 is an exploded isometric view from the back of the single elliptical strap belt-single fastener embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing, and in particular to FIGS 1a and 1b thereof, therein illustrated are two embodiments of an orthopedic device according to the present invention, generally designated by the reference numeral 10. Each embodiment comprises basically a flexible belt generally designated by the reference numeral 12, a flexible flat body generally designated 14 attached to the belt 12, and a resiliently contoured lumbar support pad generally designated 16 centrally attached to the body 14. Each belt 12 is in turn formed of at least one strap 20 and at least one fastener 18, the strap 20 transversing the pad 16 and being secured to the body at points laterally beyond the pad 16 for positioning the pad 16 on the wearer. More particularly, FIG. la illustrates a device 10a with one strap 20a adapted to be secured to the wearer with a single fastener 18a, and FIG. 1b illustrates a device 10b with two straps 20b adapted to be secured to the wearer with a dual fastener 18b.
Referring now to FIG. 2, the device 10 is shown secured to the wearer, in an overhead sectional view, looking down, with the wearer's spine at the top of the drawing. The multisection bilevel articulated contoured lumbar support pad 16 conforms to the contour of the back in the lumbar area, providing support to the vertabrae 22 and surrounding erector muscles 24.
Referring now to FIGS. 3A and 3B, therein illustrated are the two embodiments 10a and 10b, respectively. The strap design of each provides balanced distribution of support from the top of the device to the bottom of the device, where it covers the lumbar region of the back. Referring now to FIG. 3a, the single strap construction device 10a has a single strap 20a configured in an elliptical pattern. The strap 20a is secured to body 14a (e.g., by stitching) exclusively beyond the lumbar support pad 16a, the left side of top strap portion 30 being stitched over bottom strap portion 32, and the right side of top strap portion 30 being stitched under bottom strap portion 32. This construction pulls across the back freely and equally through the width of the device 10a. The elliptical construction gives the support of dual straps in the rear against the lumbar area, with the convenience and comfort of a single strap 20a with a single fastener 18a in front (see FIG. 1a).
Referring now to FIG. 3b, the dual strap support construction device 10b has two vertically spaced straps 20b in a parallel dual strap-dual fastener configuration with the straps 20b attached to the body 14b (e.g., by stitching) exclusively beyond the lumbar support pad 16b and in parallel disposition. This construction provides dual strap support across the rear of the device 10b, with the added ability of precise adjustment of each strap 20b for maximum precision of fit (see FIG. 1b). The two straps 20b optimally trisect the body 14b into three sections of generally equal width along a vertical axis.
FIG. 4 is a schematic view showing the stages of a preferred method of construction of the lumbar support pad 16. Beginning with a rectangular sheet of synthetic fiber web pack cloth 40, the cloth is fashioned into an envelope 42 to accommodate the precut synthetic rubber sections 44 that form the pad. There are three lateral or side-by-side sections: two single piece outer sections 44a of equal size that are to be positioned at the erector muscles, and a larger and thicker three piece center section 44b that forms a camber or inwardly convex shape to fill the gap between the erector muscles 24 and the spine 22, as best seen in FIG. 2. An overhead sectional view of the center section 44b, with the base at the bottom of the view, resembles the cross section of a railroad rail or an I-beam, optionally with rounded edges. The sections of synthetic rubber 44a, 44b are inserted into the envelope 42, and the envelope 42 is stitched at 46, between each individual section, to form the articulated multisection contoured lumbar support pad 16. The remaining cloth of the envelope 42 above and below the padding 44a, 44b is optionally folded behind the padding and stitched in this position to provide the finished lumbar support pad 16. Clearly the lumbar support pad 16 can be formed in other ways as well ---- e.g., using a single precut or molded synthetic rubber section of appropriate configuration within the envelope for either the center section 44b or even the entire padding 44.
FIG. 5 is an exploded view from the back showing preferred construction of the single strap-single fastener embodiment 10a and its elliptical cross-joining strap configuration. Strap 20a is anchored on the outer face of body 14a at one center end point a. The strap is disposed in an upward arc reaching its apex b near the upper edge of the middle of the body 14a and then descending to complete the arc at the opposite center end point c of the body 14a, where it turns inward to form a loop 50 extending through a slot of fastener frame 52 and returns to end point c. The strap 20a then descends from end point c of the body 14a in a downward arc reaching its nadir d near the lower edge of the middle of the body 14a (opposite the apex b) and then rises to cross-join and overlap the point of origin a, completing the elliptical circuit abcd. Finally, the strap 20a extends beyond point a to form a tongue or free end 54 for fastening.
The multisection bilevel articulated contoured lumbar support pad 16a is now secured centrally to the inner face of body 14a, for example, by stitching. Tape fastener system 56 may be secured to the outer face of tongue 54 either before or after application of strap 20a to the body 14a. A pad 58 is preferably applied to strap 20a behind fastener frame 52 for comfort and to prevent chafing of the wearer.
When the end of strap 20a forming the tongue 54 and the fastener frame 50 at the opposite end of the strap 20a are pulled towards each other, force is exerted simultaneously along the bottom strap portion 32 and along the top strap portion 30, resulting in a distribution of support across substantially the full vertical plane of the device 10a at the lumbar region. Support across the width of the back resists the tendency of the device to conform to the vertical curvature of the body, and thereby prevents the attached lumbar support pad 16a from moving away from the back and thereby reducing its effectiveness.
In both the single and dual strap embodiments 10a, 10b, the lumbar support pad 16 extends substantially from the top of the body 14 to the bottom of the body 14 and from the top of the belt 12 to the bottom of the belt 12, thereby providing support at the lumbar of the wearer across the width of the device (that is, the height of the pad 16 along its vertical axis).
The bodies 14 and belt straps 20 can be made from a wide variety of materials, including natural or organic materials such as leather, without affecting their functionality. Each belt strap 20 is preferably made from a single piece of flat synthetic fiber web, and the body 14 is preferably of unitary, one-piece, integral construction made of an elongate flat piece of synthetic fiber web. The lumbar support pad 16 is preferably made from a single piece of synthetic fiber web pack cloth forming an envelope and a contoured resilient synthetic rubber padding disposed in the envelope. The term "synthetic fiber web" refers to the family or families of man-made materials selected for their strength, flexibility, light weight, durability, cost, availability, and consistency ---- e.g., nylon and related man-made fibrous materials.
The padding substance is central to the construction of the contoured lumbar support pad 16. A solid elastic substance with the properties of firmness in texture and resilience is required. Synthetic rubber is preferably used because these properties can be acquired precisely and consistently. A preferred synthetic rubber material is available under the tradename Rubatex.
The useful fasteners 18 for securing the device 10 to the wearer are varied. A fastener system that permits precise incremental or continuous adjustments is required for maximum effectiveness, although fastener systems permitting only discrete or fixedly spaced adjustments may be used. A slide-lock buckle, a tape fastener system (e.g., a hook and loop type tape fastener of the type available under the trade name Velcro), a combination of both, or similar incrementally adjustable fasteners are preferred. The devices are described herein as using a tape fastener system.
The terms "contoured" and "articulated," as used herein to describe the lumbar support pad 16 indicate, respectively, that the face thereof adjacent the wearer is not planar or flat, and that the various outer sections 44a thereof are movable (i.e., articulated) relative to the central section 44b thereof, thereby allowing the pad face adjacent the wearer's back to conform thereto.
The present invention also encompasses a more economical, but possibly less comfortable, embodiment of the orthopedic device wherein there is no flexible flat body and the flexible belt 12 is operatively secured (e.g., by stitching) to the lumbar support pad 16 adjacent a pair of opposed ends thereof in the horizontal plane.
To summarize, the present invention provides an orthopedic device affording balanced, equal, and uninterrupted support to the lumbar region along the entire horizontal and vertical planes thereof. The device is of simple and rugged construction, economical to manufacture, use and maintain.
Now that the preferred embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be construed broadly and limited only by the appended claims, and not by the foregoing disclosure.
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An orthopedic device to provide lower back support for a wearer includes a flexible flat body, a resilient contoured lumbar support pad of varying thickness secured to the body, and a flexible belt traversing the pad and secured to the body at points beyond the pad, the belt being configured and dimensioned to be secured about the waist of the wearer for positioning the pad on the lumbar region of the wearer.
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BACKGROUND OF THE INVENTION
This invention relates to the preparation of pteridine compounds.
The folic acid antimetabolites N-[4-[[(2,4-diamino-6-pteridinyl)-methyl]amino]benzoyl]-L-glutamic acid (aminopterin) and N-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-L-glutamic acid (methotrexate) were synthesized nearly thirty years ago. Although aminopterin has been used as a folic acid antagonist in the treatment of leukemia and remains of interest for use as a rodenticide, it has not become as important in cancer chemotherapy as methotrexate, which has been in extensive clinical use for over 20 years. Methotrexate has become even more prominent in recent years through its use in newly developed clinical procedures involving its administration in massive doses followed by treatment with citrovorum factor. The use of methotrexate in this manner has greatly increased demands for production.
The usefulness of aminopterin and methotrexate as anticancer agents prompted a still-continuing search for structural variants, analogs, or derivatives that afford greater overall effectiveness. Drawbacks and limitations in available processes for preparing compounds structurally related to these antimetabolites by the common feature of the (2,4-diamino-6-pteridinyl)methyl grouping (unsubstituted at the 7-position) have caused many investigators to seek new synthetic approaches. The improvements needed in order to increase the attainable types and numbers of related compounds are greater versatility, percentage yields, and ease of purification of the products.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide a method of making pteridine compounds which provides a high yield, versatility, and ease of purification of the products.
It is another object of the present invention to provide a method for making methotrexate, aminopterin, and related compounds, which is free of the aforementioned and other such disadvantages.
The method according to the present invention achieves these objects and concomitantly furnishes improved syntheses of aminopterin, methotrexate, and related compounds.
The method of the invention provides for the union of the (2,4-diamino-6-pteridinyl)methyl grouping with diverse side chains. This result is achieved by nucleophilic displacement reactions of 2,4-diamino-6-(bromomethyl)pteridine hydrobromide (I) with amino, hydroxyl, and sulfhydryl functions of amines (aromatic and aliphatic), phenols, and thiophenol under appropriate accessary conditions.
Nearly all previously reported work on compounds conceivably or actually attainable by the use of I has involved the introduction of the (2,4-diamino-6-pteridinyl)methyl grouping at amine functions. Four methods have been used. Each is mentioned briefly below. Comments are given on the general synthetic utility of each of the four methods in comparison with that of the new process. Specific evaluative comparisons are made when possible in terms of methotrexate. Two previously used methods for attachment of the (2,4-diamino-6-pteridinyl) methyl grouping to oxygen are described after the background on amino compounds. Apparently, analogous sulfur compounds have not been reported.
Until recently, synthetic approaches used for the preparation of aminopterin, methotrexate and related compounds were adaptations of a method used for the preparation of N-[4-[[(2-amino-4-hydroxy-6-pteridinyl)methyl]amino]benzoyl]-L-glutamic acid (folic acid) generally known as the Waller procedure. This procedure involves the reaction, in one mixture, of three separate organic components: a 4,5-diaminopyrimidine, a suitable three-carbon compound, and an aromatic amine. Adaptation of the Waller procedure to prepare methotrexate thus employs 2,4,5,6-tetraaminopyrimidine, 2,3-dibromopropionaldehyde, and N-[(4-(methylamino)benzoyl]-L-glutamic acid. It is our understanding that methotrexate is prepared commercially by this procedure. ##STR1## In view of the complexities of the reaction mixtures, it is not surprising that the Waller procedure gives mixtures of products from which pure desired materials are obtained in low yields following the use of laborious and tedious techniques. Investigators experienced in the use of the Waller procedure have found that, with suitable choices of reaction conditions and purification techniques, yields in the range of 5-10% can be obtained. The previously reported preparation of methotrexate does not give a percentage yield. The preparation of the D-isomer by the Waller procedure was recently reported, with N-[4-(methylamino)benzoyl]-D-glutamic acid being used instead of the L-form, and a column chromatographic (ion-exchange) procedure devised for the purification of methotrexate as obtained commercially was used to advantage to obtain the pure D-form in 6.5% yield. Also in this connection, an elaborate column chromatographic (ion-exchange) method used to separate folic acid analogs has been adapted for use in an assay procedure for commercial methotrexate in order to remove impurities prior to spectrophotometric determination of intact methotrexate. The main contaminant among those removed by these chromatographic methods is N-[4-[[(2-amino-4-hydroxy- 6-pteridinyl)methyl]methylamino]benzoyl]-L-glutamic acid (N 10 -methylfolic acid). The application of column techniques would be impractical in large-scale commercial production of methotrexate. A process adaptable to commercial production that would afford methotrexate at acceptable cost, free of N 10 -methylfolic acid, and containing lesser amounts of other impurities as compared to presently available commercial methotrexate would provide obvious advantages. The present process offers those advantages in facile syntheses of methotrexate and various analogs.
A recently developed multistep route in which 2-amino-3-cyano-5-(chloromethyl)pyrazine 1-oxide serves as the key intermediate has been used to prepare the pure diethyl ester of methotrexate and some analogs with altered side chains. The chloromethyl group of the key intermediate in this process affords diversity in the attachment of side chains in the same functional manner as the bromomethyl group of I. An important difference, however, is that the use of I allows direct attachment of the (2,4-diamino-6-pteridinyl)methyl grouping to the side chain while two steps yet remain after the nucleophilic displacement step using 2-amino-3-cyano-5-(chloromethyl)pyrazine 1-oxide. In the sequence leading to methotrexate diethyl ester shown below, removal of the 1-oxide function by treatment with triethyl phosphite was followed by formation of the substituted pteridine ring by condensation of the 2-amino-3-cyanopyrazine system with guanidine. ##STR2## The overall yield of pure methotrexate diethyl ester obtained by the above route was calculated from the reported stepwise yields to be 15%, and column chromatographic procedures were used at two points in the process. In contrast, methotrexate itself was obtained in 59% overall yield (for two steps) after hydrolysis in situ of the diethyl ester prepared directly from I and the same side-chain intermediate by the present method.
Earlier studies on new approaches to methotrexate analogs led to a multistep route to 4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoic acid. This route is potentially applicable to the synthesis of methotrexate, but it is too lengthy (11 steps) to be considered for use in a synthesis otherwise achievable through use of I.
The only other process of which we are aware that has been used to introduce the (2,4-diamino-6-pteridinyl)methyl grouping at amino groups is restricted to the production of secondary amines. It consists of condensation of highly unstable 2,4-diamino-6-pteridinecarboxaldehyde with a primary amine under reducing conditions (H 2 , PtO 2 ) to produce a secondary amino group at the point of juncture of the two reactants. Concomitant reduction of the 7,8 double bond of the pteridine ring is reversed by oxidation with iodine. This process is, therefore, not applicable to the synthesis of methotrexate or any analog derivable by the procedures mentioned above from a starting compound already bearing a secondary amino group. It has been used to prepare a homolog of aminopterin in a sequence beginning with the aldehyde and diethyl N-[4-(aminomethyl)benzoyl]-L-glutamate as outlined below. ##STR3## The preparative procedure is scantily described in the published report. Reference is made to the preparation of the corresponding folic acid homolog, which was purified by paper chromatography. The only advantage that this approach appears to offer over that of the present invention is that it affords an umabiguous route to symmetrically substituted hydrazino types where one of the substituents is the (2,4-diamino-6-pteridinyl)methyl grouping. Obvious disadvantages are (1) the restriction to aminopterin types, (2) the lack of stability of the key intermediate, and (3) the attendant complexities that lead to apparently troublesome purification problems.
Little has been published on aminopterin analogs in which the (2,4-diamino-6-pteridinyl)methyl grouping is attached through oxygen to side chains. The 10-oxa analog of aminopterin, N-[α-(2,4-diamino-6-pteridinyl)-4-anisoyl]-L-glutamic acid, and α-(2,4-diamino-6-pteridinyl)-4-anisic acid shown below were obtained only as crude products following condensation of 2,4,5,6-tetraaminopyrimidine with diethyl N-[4-(3,3-diethoxy-2-oxopropoxy)-benzoyl]-L-glutamate and ethyl 4-(3,3-diethoxy-2-oxopropoxy)benzoate, respectively. A facile preparation of the pure 10-oxa analog of aminopterin through appropriate use of I is described below ##STR4## From a method viewpoint, the process mentioned earlier involving the use of 2-amino-3-cyano-5-(chloromethyl)pyrazine 1-oxide could be applied to the synthesis of the 10-oxa analogs shown above. The only related synthesis that has actually been done by that method is that of 2,4-diamino-6-(methoxymethyl)-pteridine.
Before proceeding with a description of the process of the instant invention for making methotrexate, aminopterin, and related compounds, it should be noted that the preparation of I has not heretofore been reported and, therefore, it is still another object of the present invention to provide a process for the production of 6-(bromomethyl)-2,4-diaminopteridine hydrobromide.
According to this aspect of the present invention, 2,4-diamino-6-pteridinemethanol obtained from the condensation of 2,4,5,6-tetraaminopyrimidine and 1,3-dihydroxyacetone according to a reported procedure is converted to its hydrobromide and then treated with triphenylphosphine dibromide or phosphorous tribromide.
Generally, the method of making I and the methotrexate, aminopterin, or other related compounds, follows the following scheme.
______________________________________ ##STR5## ##STR6## ##STR7## ##STR8##Designation of Y Groupings in Compounds 2-31Compound No. Y Grouping*______________________________________2 N(CH.sub.3)C.sub.6 H.sub.4 CONHCH(CO.sub.2 H)(CH.sub.2).sub.2 CO.sub.2 H3 NHC.sub.6 H.sub.4 CONHCH(CO.sub.2 H)(CH.sub.2).sub.2 CO.sub.2 H4 NHC.sub.6 H.sub.4 CH.sub.2 CONHCH(CO.sub.2 H)(CH.sub.2).sub.2 CO.sub.2 H5 NHC.sub.6 H.sub.4 (CH.sub.2).sub.2 CONHCH(CO.sub.2 H)(CH.sub.2). sub.2 CO.sub.2 H6 NHC.sub.6 H.sub.4 SO.sub.2 NHCH(CO.sub.2 H)(CH.sub.2).sub.2 CO.sub.2 H (as Mg salt) ##STR9##8 NHC.sub.6 H.sub.4 CH.sub.2 CONHCH(CO.sub.2 H)CH.sub.2 CO.sub.2 H9 NHC.sub.6 H.sub.4 CONH(CH.sub.2).sub.3 CO.sub.2 H10 NHC.sub.6 H.sub.4 CONHCH.sub.2 CO.sub.2 H11 N(CH.sub.3)C.sub.6 H.sub.4 CO.sub.2 H12 NHC.sub.6 H.sub.4 CONH.sub.213 NHC.sub.6 H.sub.4 CONH(CH.sub.2).sub.2 CH.sub.314 NHC.sub.6 H.sub.4 CON(CH.sub.3).sub.215 NHC.sub.6 H.sub.4 COCH.sub.316 NHC.sub. 6 H.sub.4 NHCOCH.sub.317 NHC.sub.6 H.sub.4 (CH.sub.2).sub.2 NHCOCH.sub.318 NHC.sub.6 H.sub.4 OCH.sub.319 NHC.sub.6 H.sub.4 Cl20 N(CH.sub.3)C.sub.6 H.sub.521 NHC.sub.6 H.sub.522 N(CH.sub.3)(CH.sub.2).sub.4 CONHCH(CO.sub.2 CH.sub.3)(CH.sub.2). sub.2 CO.sub.2 CH.sub.323 N(CH.sub.3)(CH.sub.2).sub.4 CONHCH(CO.sub.2 H)(CH.sub.2).sub.2 CO.sub.2 H24 NH(CH.sub.2).sub.2 C.sub.6 H.sub.525 NH(CH.sub.2).sub.3 O(CH.sub.2).sub.2 OCH.sub.2 CH.sub.326 ##STR10##27 OC.sub.6 H.sub.4 CONHCH(CO.sub.2 C.sub.2 H.sub.5)(CH.sub.2).sub. 2 CO.sub.2 C.sub.2 H.sub.528 OC.sub.6 H.sub.4 CONHCH(CO.sub.2 H)(CH.sub.2).sub.2 CO.sub.2______________________________________ H
Keeping in mind that the method of making I according to one aspect of the present invention has already been described in general terms, according to the second aspect of the present invention, the method of making pteridine compounds according to the invention may be represented as follows:
The method of making pteridine compounds represented by the formula: ##STR11## wherein Y is a member selected from the group consisting of --NRR 1 R 2 , --NH(CH 2 ) 2 C 6 H 5 , ##STR12## --OR 3 , and --SC 6 H 5 ;
R is H or CH 3 ;
R 1 is --C 6 H 4 R 4 , ##STR13## or --(CH 2 ) m --;
R 2 is --H, --CONHCH(COOR 5 )(CH 2 ) n COOR 5 , --CONHCH 2 COOH, --COOH, --CONH 2 , --CONH(CH 2 ) 2 CH 3 , --CON(CH 3 ) 2 , --COCH 3 , --NHCOCH 3 , --CONH(CH 2 ) 3 CO 2 H, --(CH 2 ) 2 NHCOCH 3 , --OCH 3 , --Cl, or --O(CH 2 ) 2 OCH 2 CH 3 ;
R 3 is C 6 H 4 R 6 ;
R 4 is (CH 2 ) p or (SO 2 ) q ;
R 5 is --H or --CH 3 ;
R 6 is --H, --CONHCH(COOC 2 H 5 )(CH 2 ) 2 COOC 2 H 5 , --CONHCH(COOH)(CH 2 ) 2 COOH, or --CONH 2 ;
m is 2, 3 or 4; n is 1 or 2; p is 0, 1 or 2; and q is 0 or 1
comprising reacting 6-(bromomethyl)-2,4-diaminopteridine hydrobromide with a compound represented by the formula HY, where Y is as defined above, in a reaction medium of N,N-dimethylacetamide or N,N-dimethylformamide and recovering said pteridine compound.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The starting material, 2,4,5,6-tetraaminopyrimidine was condensed with 1,3-dihydroxyacetone according to the procedure of C. M. Baugh and E. Shaw [J. Org. Chem., 29, 3610 (1964)] as described below. The crude material obtained directly from the reaction mixture was examined by proton magnetic resonance (pmr) spectroscopy in solution in deuteriotrifluoroacetic acid (CF 3 CO 2 D) and found to be predominantly the desired 2,4-diamino-6-pteridinemethanol as evidenced by signals at δ5.3 (CH 2 ) and δ9.1 (pteridine position-7). Relatively weak signals near δ2.8 (CH 3 ) and δ8.8 (pteridine ring H) in the spectrum produced by the crude product indicated the presence of one or possibly both of the 6- or 7-methyl-substituted 2,4-diaminopteridines. The hydroxymethyl compound was obtained in nearly pure form after conversion of the mixture of products to hydrobromide salts. The greater solubility of the contaminants in this form in ethanol allowed their nearly complete removal from the hydroxymethyl compound. Pure 2,4-diamino-6-methylpteridine hydrobromide was isolated from an ethanolic filtrate and identified as the 6-methyl isomer by comparisons of its uv-absorption spectra with those of an authentic sample, but no clear evidence was obtained that proved the presence of the 7-methyl isomer. A small percentage of methyl-substituted contaminant that remained in the hydroxymethyl intermediate persisted after the conversion to I (see details below), but was not detectable by pmr spectroscopy or thin-layer chromatography (tlc) in any of the products prepared from I.
The hydroxymethyl compound was converted to I by two procedures. The preferred procedure (Method A) makes use of triphenylphosphine dibromide in N,N-dimethylacetamide (DMAC). In Method B, phosphorus tribromide in N,N-dimethylformamide (DMF) was successfully used, but the yield was much lower than that afforded by Method A.
Samples of I have been stored in refrigerators in tightly sealed containers protected from light for several months without evident deterioration. Gradual darkening has been observed in samples exposed for several weeks to ordinary lighting and ambient conditions in the laboratory.
In all but two of the preparations from I given below, anhydrous DMAC was used as the reaction medium. In the exceptions (6 and 16), which were not tried in DMAC, hexamethylphosphoric triamide was used, probably to no advantage.
In the reaction of I with HY, the ratio of reactants can vary widely, but the preferred molar ratio of I to HY is from 1:1 to 1:4.
Melting points, or approximate decomposition points, are given for some of the compounds described below. They were observed on either a Mel-Temp apparatus or a Kofler Heizbank as indicated in the procedure. In general, these substituted pteridines, particularly those isolated as hydrohalides, lack meaningful melting points. They usually decompose at a high temperature without melting, and the temperature at which decomposition begins is difficult to determine and reproduce. For that reason, melting point determinations were not attempted on all of the compounds prepared. The pmr spectra were determined with a Varian XL-100-15 spectrometer in the solvent indicated (CF 3 CO 2 D or deuterated dimethyl sulfoxide, DMSO-d 6 ) using tetramethylsilane as internal reference. Chemical shifts quoted for multiplets were measured from the approximate centers, and relative integrals of signal areas are given for the assignment indicated. The uv-absorption spectra were determined with a Cary Model 14 spectrophotometer. Unless indicated otherwise, thin-layer chromatograms on all compounds in which the side chain bears a terminal carboxyl group were run on DEAE-cellulose plates using 0.5 M sodium chloride, 0.2 M in mercaptoethanol, in 0.005 M potassium phosphate buffer at pH 7.0 and were viewed by uv lamps emitting at 254 nm and 365 nm.
EXAMPLE 1
2,4-Diamino-6-pteridinemethanol Hydrobromide
2,4,5,6-Tetraaminopyrimidine.H 2 SO 4 .H 2 0(75.0 g, 0.293 mole) was added to a stirred solution of BaCl 2 .2H 2 O (71.5 g, 0.293 mole) in H 2 O (1.45 l.) at 85°-90°. The mixture was stirred rapidly at ˜90° for 15 min, cooled to 40°, and filtered from BaSO 4 , which was washed thoroughly on a funnel with H 2 O. The clear, yellow filtrate was then diluted further with H 2 O to give a volume of 4.35 l. This solution of the tetraaminopyrimidine.2HCl was then added to a solution of NaOAc (4.35 l. of 4 N) in which dihydroxyacetone (79.3 g, 0.88 mole) and cysteine.HCl.H 2 O (51.5 g, 0.293 mole) had just been dissolved. The resulting solution was stirred mechanically at room temperature while a slow stream of air was continuously passed through it for 26 hr. (Yellow-orange solid began separating after 2 hr.) The mixture was then kept in a refrigerator for 16 hr before the solid was collected, washed successively with cold H 2 O, EtOH, and Et 2 O before it was dried to constant weight in vacuo over P 2 O 5 at 25°. [The crude product mixture (47 g) was weighed in order to obtain an estimate of the volume of 48% HBr required to form hydrobromide salts.] A mechanically stirred mixture of the dried solid and EtOH (6.05 l.) was heated to 70°, and a solution of 48% HBr (28 ml) in EtOH (490 ml) was added in a thin stream while the mixture was maintained at 70°-75°. The mixture was then refluxed for about 5 min with rapid stirring while nearly all of the solid dissolved. The hot solution was treated with Norit and filtered through a Celite mat. The clear yellow filtrate was kept in a refrigerator overnight while a first crop of orange-colored solid separated. The collected solid was washed with EtOH, then dried in vacuo (56° over P 2 O 5 ) to give 17.2 g of product. The filtrate was concentrated by evaporation (rotary evaporator, H 2 O aspirator, bath to 35°) to about 2 l. and then refrigerated to give a second crop, which was dried as before, of 10.2 g; total yield 27.4 g (34%). The pmr spectrum of this material in CF 3 CO.sub. 2 D showed it to contain a barely detectable amount of methyl-substituted 2,4-diaminopteridine.HBr as evidenced by very weak signals at δ2.83 (CH 3 ) and δ8.85 (pteridine ring H). Strong signals produced by the desired product occur at δ5.28 (6-CH 2 O) and δ9.08 (C 7 -H). The proportion of desired product to the methyl-substituted contaminant was estimated from the pmr integrals to be 20:1. The pmr spectrum also revealed retention of a small amount of EtOH in the product dried as described but not enough to interfere with the conversion of it to I.
EXAMPLE 1A
2,4-Diamino-6-(bromomethyl)pteridine Hydrobromide (I) Method A
Bromine (59.6 g, 0.373 mole) was added dropwise over a 30-min period to a stirred solution of triphenylphosphine (97.7 g, 0.373 mole) in anhydrous DMAC (486 ml) kept at ˜10° (ice bath) and protected from atmospheric moisture. (Bromine remaining in the funnel was rinsed with 10 ml of DMAC). A smooth suspension containing finely divided, crystalline triphenylphosphine dibromide resulted. The 2,4-diamino-6-pteridinemethanol. HBr (25.4 g, 0.093 mole) described above was added in one portion through a powder funnel (with the aid of 10 ml DMAC). The ice bath was removed, and the stirred mixture was allowed to warm to 20°-25°. After about 1 hr, complete solution had occurred. The solution, which gradually developed a dark-red color, was kept at 20°-25° for 1 hr longer and was then chilled (ice bath) before it was treated with EtOH (72 ml). After overnight refrigeration, the solvents were removed by evaporation in vacuo (Swissco evaporator, pressure <1 mm, bath <45°). The dark, semisolid residue was stirred with two 300-ml portions of C 6 H 6 (to remove triphenylphosphine oxide), and each portion was removed from the C 6 H 6 -insoluble product by decantation. The solid that remained was dissolved with stirring in glacial AcOH (660 ml) which had been preheated to 80°. The mixture was kept in a bath at 80° until solution was complete. Tan crystalline solid separated as the dark solution was allowed to cool. Overnight refrigeration caused the AcOH to partially freeze. When it had thawed, the solid was collected, washed with chilled AcOH followed by Et 2 O, and dried in vacuo (over P 2 O 5 and NaOH pellets) at successive temperatures of 25°, 56°, and 110°. (The higher temperature was necessary for complete removal of AcOH). The yield was 15.3 g (49%). (Some runs afforded 60% yield). This sample was further purified by reprecipitation from MeOH solution (Norit) by addition of Et 2 O followed by drying in vacuo (25°, P 2 O 5 ), yield 13.0 g (42%) of pale-yellow solid. Spectral data: λ max, nm (ε × 10 -3 ), 0.1 NCl, 249 (17.3), 339 (10.5), 353 (sh); pH 7, 258 (21.2), 370 (6.87); 0.1 N NaOH, 258 (21.5), 370 (6.94); pmr (CF 3 CO 2 D), δ4.70 (s, 2, CH 2 ) and 9.08 (s, 1, C 7 --H); estimated proportion relative to the methyl-substituted contaminant, 25:1. These spectral properties are in close agreement with those of a similarly obtained sample that gave the following elemental analysis results. Anal. Calcd for C 7 H 7 BrN 6 .HBr: C, 25.02; H, 2.40; Br, 47.56; N, 25.01. Found: C, 25.22; H, 2.44; Br, 47.30; N, 24.99. The 13.0-g sample described above gave the following results. Anal. Found: C, 25.59; H, 2.79; N, 24.62. The preparation of I described above is typical of several runs that gave similar yields of material whose pmr spectra differed only slightly in the estimated proportion of I with respect to the methyl-substituted contaminant. The proportions usually ranged from 16:1 to 25:1, which corresponds to a percentage of I of 94 to 96%. Samples of I of this degree of purity proved to be suitable for use in the preparations of 2-31.
EXAMPLE 1B
(I) Method B
Anhydrous DMF (50 ml) was added in one portion with rapid stirring to freshly distilled PBr 3 (5.0 g, 18 mmoles). A mildly exothermic reaction occurred with the temperature of the resulting mixture rising to 35° within 2 min. The stirred mixture was allowed to cool to 28° while a white solid precipitated. 2,4-diamino-6-pteridinemethanol hydrobromide (5.0 g, 18 mmoles) was then added. The temperature of the stirred mixture rose rapidly to 37°, and the solids dissolved. Stirring was continued for 30 min while the temperature returned to 25°. Et 2 O (200 ml) was then added with stirring while dark semisolid material separated. The mixture was stirred for 1 hr before the supernatant was removed by decantation. The residue was stirred with more Et 2 O, which was also removed by decantation, and was then dissolved in AcOH (40 ml). The dark solution was left overnight while crude solid separated. The brown solid was collected, washed successively with AcOH and Et.sub. 2 O, and then dissolved in CH 3 OH (40 ml). Norit treatment (for about 3 min) followed by filtration through Celite gave a clear yellow solution, which was diluted with Et 2 O to precipitate I as a pale-yellow solid in 16% yield (1.0 g). Examination of this material by tlc (silica gel, 4:1 CHCl 3 --CH 3 OH) showed one major spot, which fluoresced under uv light, with an impurity remaining at the origin. A second reprecipitation from Norit-treated CH 3 OH solution by addition of Et 2 O removed most of the immobile contaminant but lowered the yield to 11% (0.68 g); pmr (CF 3 CO 2 D) δ4.7 (s, 2, CH 2 ), 9.1 (s, 1, C 7 -H), and a weak spurious signal at δ4.0 (CH 3 CO 2 CH 3 , from retained CH 3 OH after esterification with the solvent). The proportion of I to CH 3 OH of 4:1 estimated from the pmr spectrum is consistent with the results of elemental analysis. Anal. Calcd for C 7 H 7 BrN 6 .HBr.0.25CH 3 OH; C, 25.31; H, 2.64; N, 24.43. Found: C, 25.14; H, 2.84; N, 24.18.
EXAMPLE 2
N-[4-[[(2,4-Diamino-6-pteridinyl)methyl]methylamino]benzoyl]-L-glutamic acid (2, Methotrexate) Trihydrate
A stirred mixture of I (0.34 g, 1.0 mmole) and diethyl N-[4-(methylamino)benzoyl]-L-glutamate (0.37 g, 1.1 mmole) in DMAC (4 ml) was kept at 53°-57° (bath temperature) for 4 hrs. (Solution occurred a few minutes after heating was started.) The dark-orange solution was cooled to room temperature before H 2 O (20 ml) and NaOH solution (2 ml of 2 N) were added successively with rapid stirring (no external cooling). The finely divided orange-yellow precipitate that formed dissolved readily with stirring. When solution occurred more H 2 O (10 ml) was added. After 16 hrs at room temperature the orange solution was treated with Norit (about 50 mg) and filtered through a Celite mat. The mat was washed with H 2 O until the washings were colorless. The combined filtrate and wash solution was treated with sufficient 1 N HCl to lower the pH to 5.5. The turbid mixture was then clarified by treatment with Norit followed by filtration through Celite as before. The filtrate (now approximately 85 ml volume) was treated with 1 N HCl to lower the pH to 4.0 where a voluminous yellow-orange precipitate formed. The mixture was refrigerated for about 2 hrs before the precipitate was collected and dried in vacuo (25°-30°, P 2 O 5 ). The dried solid (0.32 g) was dissolved in NaOH solution (20 ml of 0.08 N). After treatment with Norit and filtration as before, the pH was lowered (from 12.1) to 5.5. The faintly turbid mixture was clarified (Norit, Celite) as before, and the clear filtrate was acidified to pH 4.0. After a refrigeration period, the yellow-orange solid was collected, washed with H 2 O, and dried in vacuo (25°-30°, P 2 O 5 ) to give 2.3H 2 O in 59% yield (0.30 g). Anal. Calcd for C 20 H 22 N 8 O 5 .3H 2 O: C, 47.24; H, 5.55; N, 22.04. Found: C, 47.42; H, 5.15; N, 22.05. Spectral data: λmax, nm (ε × 10 -3 ), 0.1 NCl, 243 (18.9), 307 (22.4); pH 7, 257 (24.8), 302 (25.1), 370 (7.90); 0.1 N NaOH, 257 (25.6), 302 (25.1), 370 (8.14); pmr (DMSO-d 6 ), δ 2.05 (m, 2, CHCH 2 CH 2 ), 2,30 (m, 2, CH 2 CO 2 H), 3.20 (s, 3, CH 3 ), 4.38 (m, 1, NHCHCO 2 H), 4.82 (s, 2, CH 2 N), 6.85 and 7.73 (m, 4, C 6 H 4 ), 7.05 (broad s, 2, NH 2 ), 7.9 (very broad s, 2, NH 2 ), 8.20 (d, 1, NHCO), 8.62 (s, 1, C 7 --H); ir, identical with that of an authentic sample. A thin-layer chromatogram revealed one uv-absorbing spot (identical with that produced by authentic 2) with a very faint fluorescent spot at or near the origin. The appearance of this chromatogram agrees with the published description of that produced by the D-form of 2 prepared by the Waller procedure and purified by a method that included ion-exchange column chromatography.
The results of an independent analytical examination show that methotrexate prepared by the simple procedure given above is obtained in a better state of purity than present USP methotrexate.
EXAMPLE 3
N-[4-[[(2,4-Diamino-6-pteridinyl)methyl]amino]benzoyl]-L-glutamic Acid (3, Aminopterin) Hydrate (4:7)
A mixture of I (168 mg, 0.500 mmole) and N-(4-aminobenzoyl)-L-glutamic acid (400 mg. 1.50 mmoles) in DMAC (2 ml) was stirred at 25° under N 2 in a stoppered flask protected from light. Solution occurred after 2 hrs. After 18 hrs, the orange solution was mixed with H 2 O (15 ml) with stirring to give a finely divided, yellow precipitate. The mixture was centrifuged, and the supernatant removed by decantation. The yellow solid was stirred with four 15-ml portions of H 2 O, each of which was removed by decantation after centrifugation. The solid was then suspended in EtOH (15-20 ml), collected by filtration, washed with Et 2 O, and dried in vacuo (25°, P 2 O 5 ) to give hydrated 3 in 68% yield (160 mg). Anal. Calcd for C 19 H 20 N 8 O 5 .1.75H 2 O: C, 48.36; H, 5.02; N, 23.74. Found: C, 48.72; H, 4.91; N, 23.36. Spectral data: λ max, nm (ε × 10 -3 ), 0.1 N HCl, 244 (18.2), 290 (20.5), 335 (11.0); pH 7, 260 (26.7), 283 (25.5), 370 (8.00); 0.1 N NaOH, 260 (26.9), 283 (25.3), 370 (8.00); pmr (DMSO-d 6 ), δ2.02 (m, 2, CHCH 2 CH 2 ), 2.32 (m, 2, CH 2 , CO 2 H), 4.36 (m, 1, NHCHCO 2 H), 4.52 (s, 2, CH 2 N), 6.85 (m, 4, 2 phenylene protons plus NH 2 ), 7.72 (m, 2, phenylene), 7.86 (broad s, 2, NH 2 ), 8.13 (d, 1, NHCO), 8.72 (s, 1, C 7 -H). Examination by tlc revealed one uv-absorbing spot and no fluorescence at any point. The uv data given above is in agreement with reported results.
EXAMPLE 4
N-[4-[[(2,4-Diamino-6-pteridinyl)methyl]amino]phenylacetyl]-L-glutamic Acid (4) Monohydrate
Treatment of N-(4-aminophenylacetyl-L-glutamic acid (5.60 g, 20.0 mmoles) with I (2.24 g, 6.67 mmoles) in DMAC (25 ml) as described for the preparation of 3 was followed by dropwise addition of the dark-orange reaction solution to stirred H 2 O (250 ml). Orange solid separated, and the mixture was stirred at 25° for 30 min and then at about 5° for 1 hr before the precipitate was collected by filtration. The suction-dried solid was removed from the funnel and stirred with H 2 O (125 ml). This mixture was centrifuged, and the clear supernatant was removed by decantation. After a second wash with H 2 O followed by centrifugation and decantation, the residue was again suspended in H 2 O and collected by filtration. The suction-dried solid was then washed with Et 2 O before it was dried in vacuo (25° over P 2 O 5 ); yield 72% (2.27 g). Anal. Calcd for C 20 H 22 N 8 O 5 .H 2 O: C, 50.84; H, 5.12; N, 23.72. Found: C, 51.00; H, 4.90; N, 24.02. Spectral data: λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (18.3), 337 (10.1); pH 7, 256 (31.1), 370 (7.52); 0.1 N NaOH, 256 (31.8), 370 (7.57); pmr (DMSO-d 6 ), δ1.90 (m, 2, CHCH 2 CH 2 ), 2.28 (m, 2, CH 2 CO 2 H), 3.32 (s, 2, CH 2 CON), 4.22 (m, 1, NHCHCO 2 H), 4.44 (s, 2, CH 2 N), 6.66 (m, 4, 2 phenylene protons plus NH 2 ), 7.02 (m, 2, phenylene), 7.32 (s, 1, CH 2 NH), 7.84 (braod s, 2, NH 2 ), 8.15 (d, 1, NHCO), 8.72 (s, 1, C 7 --H). Tlc revealed one uv-absorbing spot with a very thin and faintly fluorescent cap.
EXAMPLE 5
N-[4-[[(2,4-Diamino-6-pteridinyl)methyl]amino]hydrocinnamoyl]-L-glutamic Acid (5) Dihydrate
A mixture of I (2.24 g, 6.67 mmoles) and N-(4-aminohydrocinnamoyl)L-glutamic acid (20.0 mmoles) in DMAC (25 Ml) was stirred at 25° under N 2 in a stoppered flask protected from light. The mixture gradually thinned but separation of a precipitate commenced just before solution has occurred. After 24 hrs, the mixture was poured into H 2 0 (250 ml) to give a red-orange precipitate, which was readily collected by filtration, washed on the funnel with several portions of H 2 O followed for Et 2 O, and dried in vacuo (25° over P 2 O 5 ); yield 72% (2.44 g). Tlc revealed a fluorescent spot above the dark, uv-absorbing spot and also at the origin. The crude product was then stirred with H 2 O (80 ml), and 0.1 N NaOH (100 ml) was added with stirring. The dark-red solution that formed was treated with Norit, filtered (Celite), chilled to about 5°, and treated with 0.1 N HCl (100 ml). The orange precipitate that formed was collected by filtration, washed on the funnel with H 2 O followed by Et 2 O, and dried in vacuo (25° over P 2 O 5 ); yield 38% (1.27 g). Anal. Calcd for C 21 H 24 N 8 O 5 . 2H 2 O: C, 50.00; H, 5.59; N, 22.21. Found: C, 50.38; H, 5.00; N, 22.42. (A sample obtained from a trial run in the manner and percentage yield stated above gave the following elemental analysis results. Anal. Found: C, 50.37, 50.40; H, 5.29, 5.12; N, 22.63, 22.37). Spectral data: λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (19.4), 336 (10.8); pH 7, 256 (30.9), 370 (7.80); 0.1 N NaOH, 256 (31.3), 370 (7.76); pmr (DMSO-d 6 ), δ 1.88 (m, 2, CHCH 2 CH 2 ), 2.1-2.8 (overlapping multiplets, 6, C 6 H 4 CH 2 CH 2 CO and CH 2 CO 2 H), 4.22 (m, 1, NHCHCO 2 H), 4.42 (s, 2, CH 2 N), 6.65 (m, 4, 2 phenylene protons plus NH 2 ), 6.69 (m, 2, phenylene), 7.80 (broad s, 2, NH 2 ), 8.05 (d, 1, NHCO), 8.70 (s, 1, C 7 --H). Tlc showed one uv-absorbing sopt with a thin, faintly fluorescent cap and a barely discernible fluorsecent spot at the origin.
EXAMPLE 6
N-[4-[[(2,4-Diamino-6-pteridinyl)methyl]amino]benzenesulfonyl]-L-glutamic Acid (6), Magnesium Salt, Heptahydrate
A solution of I (2.63 g, 7.82 mmoles) and N-(4-aminobenzenesulfonyl-L-glutamic acid (2.60 g, 8.60 mmoles) in hexamethylphosphoric triamide (50 ml) was kept at about 25° for 6 days and then added to H 2 O (150 ml) with stirring. The mixture was refrigerated for about 4 hrs before it was centrifuged. The dark gel-like precipitate was washed with H 2 O (three times with 25-30 ml portions) until the clear supernatant following centrifugation became pale-yellow (as opposed to dark-orange initially). The precipitate, still as dark hydrous gel, was stirred with H 2 O (120 ml) and treated with NaOH solution (2 ml of 4 N). The dark-orange solution that formed was treated with Norit and filtered (Celite mat) to give a pale-orange filtrate which was treated with glacial AcOH to produce pH 4.0. A yellow gel-like precipitate formed. Following overnight refrigeration, the mixture was centrifuged and the residue was washed once with H 2 O as before and then Me 2 CO. Following decantation after centrifugation from the Me 2 CO wash, the residue was again suspended in Me 2 CO, collected by filtration, washed with Me 2 CO followed by Et 2 O, and dried in vacuo (25°, P 2 O 5 ) to give crude 6 as a brown solid (1.29 g). This material was treated in boiling H 2 O (100 ml) with MgO (500 ml) with rapid stirring, and, after about 5 min all the brown solid had dissolved. The hot mixture was clarified (Norit, Celite,) and the clear yellow filtrate was refrigerated overnight while the Mg salt of 6 separated as a yellow-solid. The mixture was centrifuged, and the Mg salt was washed once with cold H 2 O (20 ml). After centrifugation, the wash solution and the first decantate were combined and set aside for further processing. The solid was then suspended in Me 2 CO, collected by filtration, washed with Et 2 O, and air dried to constant weight (0.95 g) before it was recrystallized from the minimum volume of hot H 2 O (about 30 ml) to give the pure Mg salt as pale-yellow lustrous crystals, which were collected as before and dried in vacuo (25°, P 2 O 5 ). The sample was then allowed to equilibrate with ambient conditions of the laboratory whereupon it underwent a weight increase (from 0.60 g to 0.76 g) that corresponds to transformation of the anhydrous salt to a heptahydrate. Elemental analysis results agree with that indication. The yield was 16%. Anal. Calcd for C 18 H 18 MgN 8 O 6 S.7H 2 O: C, 34.60; H, 5.16; Mg, 3.89; N, 17.93. Found: C, 34.28; H, 5.24; Mg, 3.64; N, 17.67. Spectral data: λ max, nm (ε × 10 -3 ), 0.1 N HCl, 245 (17.3), 272 (25.0), 337 (10.6); pH 7, 266 (33.5), 370 (7.82); 0.1 N NaOH, 263 (35.4), 372 (8.04); pmr (CF 3 CO 2 D), δ 2.25 (m, 2, CHCH 2 CH 2 ), 2.73 (m, 2, CH 2 CO 2 H), 4.36 (m, 1, NHCHCO 2 H), 5.30 (s, 2, CH 2 N), 7.85 and 8.18 (m, 4, C 6 H 4 ), 9.02 (s, 1, C 7 --H). The sample was homogeneous according to tlc (one uv-absorbing spot).
The filtrate from the recrystallization step and the decantate from the centrifugation step were combined, and the pH of the solution was lowered by addition of AcOH from 8.5 to 4.0 to give the acid 6 as a pale-yellow solid (0.45 g). Examination of this product by tlc with the pure Mg salt as reference showed the acid to contain impurities that produced pale fluorescent streaks above and below the expected uv-absorbing spot. Further purification of the free acid was not pursued since the pure Mg salt was suitable for testing purposes.
EXAMPLE 7
N-[[5-[[(2,4-Diamino-6-pteridinyl)methyl]amino]-2-pyridinyl]-carbonyl]-L-glutamic acid (7, 2'-Azaaminopterin) Monohydrate
Diethyl N-[(5-amino-2-pyridinyl)carbonyl]-L-glutamate (3.076 g, 9.5 mmoles) and I (3.19 g, 9.5 mmoles) were dissolved in dry DMAC (40 ml). The flask was flushed with N 2 and sealed, and the reaction mixture was stirred at about 25° for 7 days in the dark. The DMAC was removed by evaporation in vacuo, and the residue was dissolved in a solution consisting of H 2 O (230 ml), EtOH (200 ml), and NaOH solution (48 ml of 1 N). This solution was kept in a stoppered flask under N 2 at about 25° for 6 hrs. The solution was then neutralized to pH 7, and the EtOH was evaporated in vacuo. The volume of the aqueous solution remaining was increased to 500 ml, and the precipitate obtained by acidification to pH 4 was isolated and washed with H 2 O by centrifugation. The wet cake was freeze-dried to a brown solid (3.85 g). A solution (pH 8) of 3.2 g of this material in dilute KOH solution (200 ml) was treated with Norit and then filtered through Celite. The filtrate was neutralized to pH 7, and the Norit treatment was repeated. The resulting filtrate was acidified to pH 4, and the precipitate was isolated and washed with H 2 O by centrifugation. Treatment of the wet cake with Me 2 CO afforded a solid (1.64 g) which was isolated by filtration. This solid was purified by column chromatography using DEAE-cellulose (Mannex Regular Low Capacity; column dimensions 4.2 × 51 cm) prepared in the following manner. The dry DEAE-cellulose (150 gm) was hydrated, and the fines were removed so that about one-half of the original DEAE-cellulose remained. This material was deaerated, poured into the column and then washed successively with potassium phosphate buffer of pH 7.0 (3 l.), H 2 O (10 l.), and 0.2 M aqueous 2-mercaptoethanol (2 l.). The crude product was dissolved in dilute aqueous KOH (1.5 l.) which was 0.2 M in 2-mercaptoethanol, and this solution (pH 6.5) was applied to the column. The column was washed with 0.2 M aqueous 2-mercaptoethanol (1 l.) and then eluted using a stepwise gradient (0.1-0.3 M) of NaCl solutions of pH 7.0, 0.2 M in 2-mercaptoethanol and 0.005 M in potassium phosphate buffer. The uv absorbance of the column eluate was monitored continuously at 300 nm. The product moved down the column as a yellow-orange zone, and the product-containing fractions were divided into four groups according to their uv absorbance. Each fraction group was acidified (1 N HCl) to pH 4 and refrigerated. The individual precipitates were isolated by centrifugation and redissolved in H 2 O (200 ml) containing 2-mercaptoethanol (2 ml) by the addition of 1 N KOH to pH 8. These solutions were filtered, and the filtrates were acidified to pH 4 and refrigerated. The yellow precipitates were isolated and washed with H 2 O (four times) by centrifugation. The supernatant solutions were retained for lyophilization, and the wet precipitates were freeze-dried to yellow amorphous solids. On the basis of tlc analysis, three of these solids were combined (220 mg). The fourth solid and the solid obtained by lyophilization of the combined supernatant washes were redissolved in dilute KOH solution as before, and these solutions (pH 7) were treated with Norit and filtered. Acidification of the filtrates, and isolation and freeze-drying of the precipitates as before afforded an additional 178 mg of product. The total yield was 11% (398 mg). Anal. Calcd for C 18 H 19 N 9 O 5 .H 2 O: C, 47.06; H, 4.61; N, 27.44. Found: C, 47.08; H, 4.58; N, 27.51. Spectral data: λ max, nm (ε × 10 -3 ), 0.1 N HCl, 223 (22.3). 242 (21.6), 290 (19.2), 342 (18.9); pH 7, 259 (24.6), 282 (21.4), 305 (sh), 370 (7.94); 0.1 N NaOH, 259 (24.7), 282 (21.1), 305 (sh), 370 (8.13); pmr (CF 3 CO 2 D), δ 2.00-2.67 (overlapping multiplets, 4, CH 2 CH 2 ), 5.00 (s, 2, CH 2 N), 5.07 (m, 1, NHCHCO 2 H), 7.90 (doublet of doublets, 1, C 5' --H), 8.43 (d, 1, C 6' --H), 8.47 (d, 1, C 3' --H), 9.05 (s, 1, C 7 --H).
EXAMPLE 8
N-[[4-[[(2,4-Diamino-6-pteridinyl)methyl]amino]phenyl]acetyl]-L-aspartic Acid (8) Hemihydrate
N-[(4-Aminophenyl)acetyl]-L-aspartic acid (2.34 g, 8.8 mmoles) and I (2.69 g, 8 mmoles) were dissolved in DMAC (40 ml). The flask was flushed with N 2 and closed, and the reaction mixture was stirred at about 25° for 4 days in the dark. The reaction mixture was filtered, and the solid on the funnel was washed with DMAC. The filtrate was treated with H 2 O (250 ml), and the suspended product was dissolved by addition of the minimum of 1 N NaOH. The solution (pH 7.5) was treated with Norit and filtered through Celite. The filtrate was acidified to pH 6.2, and the mixture was clarified (Norit, Celite) as before. Acidification of the filtrate to pH 4 afforded an orange precipitate, which was isolated by centrifugation and then redissolved as before by addition of 1 N NaOH as required to a suspension in H 2 O (250 ml). This solution was acidified to pH 6.3 and clarified (Norit, Celite) once more. The filtrate was acidified to pH 3.9 and refrigerated. The orange precipitate was isolated and washed with cold H 2 O (four times) by centrifugation. The wet product was lyophilized, pulverized, and dried further in vacuo over P 2 O 5 for 24 hrs; yield 37% (1.3 g). Anal. Calcd for C 19 H 20 N 8 O 5 .0.5H 2 O: C, 50.78; H, 4.71; N, 24.93. Found: C, 50.69; H, 4.72; N, 25.09. Spectral data: λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (19.6), 291 (5.69), 337 (10.3), 349 (sh); pH 7, 257 (31.7), 370 (7.49); 0.1 N NaOH, 257 (32.4), 370 (7.92); pmr (CF 3 CO 2 D), δ 3.27 (m, 2, CH 2 CO 2 H), 3.93 (s, 2, C 6 H 4 CH 2 CO), 5.17 (m, 1, CHNH), 5.23 (s, 2, CH 2 NH); 7.60 (s, 4, C 6 H 4 ), 9.0 (s, 1, C 7 --H).
EXAMPLE 9
4-[N-[4-[[(2,4-diamino-6-pteridinyl)methyl]amino]benzoyl]amino]-butyric Acid (9) Hydrobromide Hydrate with N,N-Dimethylacetamide (20:20:12:5)
A suspension of 4-(4-nitrobenzamido)butyric acid (1.12 g, 4.75 mmoles) in H 2 O (55 ml) was hydrogenated in the presence of a 5% palladium-on-charcoal catalyst at room temperature and atmospheric pressure. The catalyst was removed by filtration, and the filtrate was evaporated to dryness in vacuo. The resulting residue of 4-(4-aminobenzamido)butyric acid (1.02 g) was dissolved in DMAC (10 ml) containing I (504 mg, 1.50 mmoles), and the whole was stirred at about 25° for 60 hrs. The precipitate of the product was collected by filtration, washed with Et 2 O and dried in vacuo (78°, P 2 O 5 ) for 68 hrs; yield 63% (483 mg). This sample decomposed from about 240° (Mel-Temp) and was homogeneous by tlc (5:1 CHCl 3 --MeOH). Anal. Calcd for C 18 H 20 N 8 O 3 .HBr.0.60H 2 O.0.25 DMAC: C, 44.75; H, 4.83; N, 22.66. Found: C, 44.54; H, 4.81; N, 22.34. Spectral data: λ max, nm (ε × 10 -3 ), 0.1 N HCl, 244 (16.6 Z); 287 (16.9), 337 (9.58); pH 7, 261 (24.4), 279 (22.4), 370 (6.82); 0.1 N NaOH, 260 (24.7 ), 279 (22.6), 370 (7.06); pmr (DMSO-d 6 ), δ 1.72 (m, 2, CH 2 CH 2 CH 2 ), 2.25 (m, 2, CH 2 CO 2 H), 3.23 (m, 2, CONHCH 2 ), 4.63 (s, 2, CH 2 N), 7.22 (m, 4, C 6 H 4 ), 8.09 (m, 1, NHCO), 8.86 (s, 1, C 7 --H), 9.34 (NH). The pmr spectrum also showed the presence of DMAC; the NH 2 and CO 2 H groups were too broad to locate but are observed in the integral.
EXAMPLE 10
N-[4-[[(2,4-Diamino-6-pteridinyl)methyl]amino]benzoyl]glycine (10) Sesquihydrate
A solution of I (1.01 g, 3.00 mmoles) and N-(4-amino-benzoyl)glycine (640mg, 3.30 mmoles) in DMAC (10 ml) was stirred under N 2 in a stoppered flask protected from light for 4 days. The yellow precipitate that formed was collected by filtration, washed with DMAC (twice with 4-ml portions), suspended in H 2 O (200 ml), and dissolved by addition of the required volume of 1 N KOH. The solution (pH 11) was treated with Norit and filtered (Celite mat). The filtrate was brought to 400 ml volume, acidified to pH 4 by addition of 1 N HBr, and refrigerated. The yellow precipitate that formed was isolated and washed (four times) with H 2 O by centrifugation. The solid was finally suspended in Me 2 CO (350 ml), collected by filtration, and dried in vacuo; yield 55% (604 mg). Anal. Calcd for C 16 H 16 N 8 O 3 .1.5H 2 O: C, 48.60; H, 4.84; N, 28.34. Found: C, 48.82; H, 4.85; N, 28.40. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 244 (18.0), 288 (20.7), 336 (11.2 ), 348 (sh); pH 7, 260 (27.5), 282 (25.4), 371 (8.20); 0.1 N NaOH, 260 (27.1), 282 (25.4), 371 (8.20); pmr (CF 3 CO 2 D), δ 4.50 (s, 2, CH 2 CO 2 H), 5.34 (s, 2, CH 2 N), 8.00 (m, 4, C 6 H 4 ), 9.04 (s, 1, C 7 --H).
EXAMPLE 11
4-[[(2,4-Diamino-6-pteridinyl)methyl]methylamino]benzoic Acid (11) Sesquihydrate
A solution of I (168 mg, 0.500 mmole ) and 4-(methylamino)benzoic acid (83 mg, 0.55 mmole) in DMAC (2ml) was stirred at about 25° for 114 hrs and then mixed with H 2 O (18 ml) to cause separation of 11. The collected and dried solid (150 mg) was reprecipitated from Norit-treated and filtered (Celite) NaOH solution (7.5 ml of 0.08 N) by treatment with 1 N HCl to produce pH 6.5. The yellow solid was collected, washed with H 2 O, and dried in vacuo (78° over P 2 O 5 ); yield 60% (105 mg). Anal. Calcd for C 15 H 15 N 7 O 2 .1.5H 2 O: C, 51.13; H, 5.15; N, 27.83. Found: C, 51.02; H, 5.24; N, 27.52. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 240 (17.7), 311 (25.9), 350 (sh) (9.83); pH 7, 258 (25.4), 285 (22.9), 372 (7.21); 0.1 N NaOH, 258 (25.8), 285 (22.9), 372 (7.48); pmr (DMSO-d 6 ), δ 3.23 (s, 3, CH 3 N), 4.82 (s, 2, CH 2 ), 6.74 (s, 2, NH 2 ), 6.84 and 7.76 (m, 4, C 6 H 4 ), 7.58 (very broad s, 2, NH 2 ), 8.60 (s, 1, C 7 --H). The uv and pmr spectral data listed are in good agreement with reported data for a sample that gave satisfactory elemental analysis results for 11.0.65 HCl, and, surprisingly, the ir spectrum of that sample is identical with that of 11.1.5 H 2 O described above. Examination of 11.1.5H 2 O by tlc revealed one uv-absorbing spot with a barely discernible fluorescent spot just above it.
EXAMPLE 12
4-[[2,4-Diamino-6-pteridinyl]methyl]aminobenzamide (12) Hydrobromide Monohydrate
A solution of I (500 mg, 1.49 mmoles) and 4-aminobenzamide (410 mg, 2.98 mmoles) in DMAC (20 ml) was stirred at about 25° for 20 hrs. The deposit of bright yellow solid was collected by filtration, washed with cold DMAC, and dried in vacuo (25°, P 2 O 5 ); yield 330 mg. Evaporation of the filtrate gave a solid residue that was washed thoroughly with Et 2 O and EtOH; yield 220 mg. The two crops produced identical thin-layer chromatograms and were combined; total yield 94% (550 mg). Treatment of a finely ground suspension of this solid with 0.5 M NaHCO 3 solution resulted in incomplete removal of HBr. The recovered solid (0.40 g) was converted to the full hydrobromide salt by suspending it in EtOH (20 ml), adding 48% HBr (0.10 ml), and diluting slowly with Et 2 O (200 ml). The yellow solid was dried in vacuo (78°, P 2 O 5 ); yield 62% (380 mg); mp chars, but does not melt below 350° (Mel-Temp). Anal. Calcd for C 14 H 14 N 8 O.HBr.H 2 O; C, 41.09; H, 4.19; N, 27.38; Br, 19.52. Found: C, 41.23; H, 3.69; N, 27.44; Br, 19.73. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 243 (17.5), 289 (19.2), 336 (11.2); pH 7, 259 (25.0), 284 (21.6), 371 (7.9 ); 0.1 N NaOH, 259 (25.6). 284 (21.6). 371 (8.2); pmr (DMSO-d 6 ), δ 4.59 (s, 2, CH 2 N), 7.22 (m, C 6 H 4 and NH 2 ), 8.81 (m, 3, NH 2 and C 7 --H).
EXAMPLE 13
4-[[(2,4-Diamino-6- pteridinyl)methyl]amino]-N-propylbenzamide (13) Hydrobromide
A solution of 4-nitro-N-propylbenzamide (1.00 g, 4.80 mmoles) in MeOH (25 ml) was hydrogenated in the presence of a 5% palladium-on-charcoal catalyst at about 25° and atmospheric pressure. The catalyst was removed by filtration, and the filtrate was evaporated to dryness in vacuo to give 4-amino-N-propylbenzamide as a gummy residue; yiel 836 mg. This product was dissolved in DMAC (10 ml) containing I (504 mg, 1.50 mmoles), and the whole was stirred at room temperature for 72 hrs. The precipitate of the product was collected by filtration, washed with Et 2 O and dried in vacuo over P 2 O 5 ; yield 74% (482 mg), mp > 340° (Mel-Temp). This sample was homogeneous on tlc (5:1 CHCl 3 -MeOH). Anal. Calcd for C 17 H 20 N 8 O.HBr: C, 47.12; H, 4.88; N, 25.86. Found: C, 47.10; H, 5.18; N, 25.55. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 244 (18.5), 284 (18.3), 337 (10.5), 345 (sh) (9.70); pH 7, 261 (26.9). 279 (24.2), 371 (7.65); 0.1 N NaOH, 261 (27.1), 279 (24.2), 371 (7.73); δ 0.96 (t, 3, CH 3 ), 1.50 (m, 2, CH 2 CH 3 ), 3.17 (m, 2, NHCH 2 CH 2 ), 4.62 (s, 2, CH 2 N), 7.23 (m, 4, C 6 H 4 ), 8.07 (m, 1, NHCO), 8.87 (s, 1, C 7 --H), 9.35 (NH). Some of the NH 2 peaks were too broad to locate but are observed in the integral.
EXAMPLE 14
4-[[2,4-Diamino-6-pteridinyl]methyl]amino-N,N-dimethylbenzamide (14) Hydrobromide Hydrate
A solution of I (500 mg, 1.49 mmoles) and 4-amino-N,N-dimethylbenzamide (740 mg, 4.47 mmoles) in DMAC (20 ml) was stirred at about 25° for 48 hrs. The solution, which had become turbid after about 24 hrs, was evaporated to dryness in vacuo. The yellow residue was triturated thoroughly with several portions of Et 2 O. The finely pulverized solid was stirred with H 2 O (40ml), and the mixture was adjusted to pH 7.5 with 1 N NaOH. The insoluble solid was collected by filtration and washed with H 2 O by centrifugation. Elemental analysis results showed that the material obtained had been only partially converted to the free base. The product obtained in 56% yield (330 mg) underwent gradual decomposition without melting above 220° (Mel-Temp). Anal. Calcd for C 16 H 18 N 8 O.0.52HBr.H 2 O: C, 48.23; H, 5.19; Br, 10.43; N, 28.12. Found: C, 48.40; H, 5.07; Br, 10.47; N, 28.28. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 245 (21.3), 275 (12.8), 336 (10.7); pH 7, 261 (30.9), 372 (7.7); 0.1 N NaOH, 260 (32.1), 372 (7.9); pmr (DMSO-d 6 ), δ 2.94 (s, 6, CH 3 ), 4.42 (broad overlapping multiplets, CH 2 , NH, H 2 O), 7.01 (m, C 6 H 4 , NH 2 ), 8.51 (s, 2, NH 2 ), 8.78 (s, 1, C 7 --H).
EXAMPLE 15
6-[(4-Acetylphenylamino)methyl]-2,4-pteridinediamine (15) Hydrobromide
A magnetically stirred mixture of I (1.01 g, 3.00 mmoles) and 4-aminoacetophenone (1.62 g, 12.0 mmoles) in DMAC (20 ml) in a centrifuge tube became clear within 15 min, and 15.HBr began separating after 30 min. The mixture was stirred 20 hrs at 25° (stoppered under N 2 and protected from light) before it was centrifuged. Successive washes of the orange solid with DMAC (5 ml) and EtOH (three times with 15-ml portions) were each followed by centrifugation and decantation. The residue was finally stirred with Et 2 O, collected by filtration, and dried in vacuo (25°, P 2 O 5 ); yield 68% (0.80 g). Anal. Calcd for C 15 H 15 N 7 O.HBr: C, 46.17; H, 4.13; N, 25.12. Found: C, 46.45; H, 4.29; N, 25.38. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 241 (20.3), 327 (27.8); pH 7, 258 (22.0), 327 (24.1); 0.1 N NaOH, 258 (22.1), 327 (24.1); pmr (CF 3 CO 2 D), δ 2.84 (s, 3, CH 3 ), 5.36 (s, 2, CH 2 N, 7.98 and 8.33 (m, 4, C 6 H 4 ), 9.08 (s, 1, C 7 --H).
EXAMPLE 16
N-[4-[(2,4-Diamino-6-pteridinyl)methylamino]phenyl]acetamide (16) Hydrate
A mixture of I (336 mg, 1.00 mmole) and 4'-aminoacetanilide (451 mg, 3.00 mmoles) in hexamethylphosphoric triamide (6 ml) was stirred for 22 hrs and poured into H 2 O (25 ml) containing 1 N NaOH (2.0 ml). The resulting mixture was stirred in an ice bath and the orange precipitate collected, washed successively with H 2 O, 4:1 Et 2 O-MeOH and Et 2 O and dried in vacuo (100°, P 2 O 5 ); yield 69% (240 mg), mp > 260° (Kofler Heizbank). Anal. Calcd for C 15 H 16 N 8 O.1.2H 2 O: C, 52.08; H, 5.36; N, 32.39. Found: C, 51.99; H, 4.94; N, 32.38. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (30.8), 336 (10.9), 350 (sh) (9.52); pH 7, 259 (33.0), 372 (7.62); 0.1 N NaOH, 259 (34.1), 373 (7.81); pmr (DMSO-d 6 ), δ 1.96 (s, 3, COCH 3 ), 4.42 (d, 2, CH 2 N), 6.12 (s, 1, NHCH 2 ) , 6.57, 7.72 (d, NH 2 ), 6.66 and 7.32 (m, 4, C 6 H 4 ), 8.71 (s, 1, C 7 --H), 9.52 (s, 1, NHCO).
EXAMPLE 17
N-[2-[4-[[(2,4-diamino-6-pteridinyl)methyl]amino]phenyl]ethyl]acetamide (17) Hydrobromide Dihydrate
A solution of N-[2-(4-aminophenyl)ethyl]acetamide (713 mg, 4 mmoles) and I (672 mg, 2 mmoles) in DMAC (8 ml) was stirred under N 2 at about 25° in a stoppered flask protected from light for 2 days. The precipitate was isolated by filtration and the solid on the funnel was washed with DMAC (2 × 4 ml). The filtrate was set aside, and the solid was then washed with EtOH (5 ml) and H 2 O (2 × 3 ml). The addition of an equal volume of H 2 O to the DMAC filtrate afforded more product which was isolated by filtration and washed with H 2 O. Evaporation of the EtOH-H 2 O washes also afforded more product, which was triturated with Et 2 O and isolated by filtration. The combined yield was 70% (609 mg). A sample obtained in this manner was recrystallized from MeOH to give the pure product in about 50% recovery. Anal. Calcd for C 17 H 20 N 8 O.HBr.2H 2 O: C, 43.50; H, 5.37; N, 23.88. Found: C, 43 .40; H, 5.42; N, 23.82. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (17.9), 292 (5.80), 337 (10.2), 347 (sh); pH 7, 257 (27.6), 280 (sh), 372 (7.70); 0.1 N NaOH, 257 (28.6), 280 (sh), 372 (7.96); pmr (DMSO-d 6 ), δ 1.76 (s, 3, CH 3 ), 2.56 (m, 2, C 6 H 4 --CH.sub. 2 CH 2 ), 3.16 (m, 2, CH 2 NHCO), 4.52 (s, 2, CH 2 NHC 6 H 4 ), 6.80 (m, 4, C 6 H 4 ), 8.84 (s, 1, C 7 --H).
EXAMPLE 18
6-[[(4-Methoxyphenyl)amino]methyl]-2,4-pteridinediamine (18) Hydrobromide
A solution of I (2.69 g, 8.00 mmoles) and freshly recrystallized 4-methoxybenzeneamine (1.97 g, 16.0 mmoles) in DMAC (26 ml) was stirred under N 2 at about 25° in a stoppered flask protected from light for 3 days. The product that separated was collected under N 2 in subdued light, and washed with DMAC, H 2 O , and EtOH. Subsequent operations were also carried out in subdued light and under N 2 whenever possible. The solid was dried in vacuo (25°, P 2 O 5 ) to give crude 18.HBr in 56% yield (1.68 g). Recrystallization of part (1.28 g) of this material from MeOH led to two crops of brick-red 18.HBr (555 and 219 mg). The second smaller crop was slightly less pure than the first, which gave the following analytical results. Anal. Calcd for C 14 H 15 N 7 O.HBr.0.1CH 3 OH: C, 44.40; H, 4.33; N, 25.70. Found: C, 44.59; H, 4.12; N, 25.94. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (19.0), 337 (10.6), 348 (sh); pH 7, 257 (26.6), 280 (sh), 3.72 (7.70); 0.1 N NaOH, 257 (27.1), 280 (sh), 372 (7.80); pmr (DMSO-d 6 ), δ 3.17 (s, CH 3 OH solvate), 3.64 (s, 3, CH 3 O), 4.50 (s, 2, CH 2 N), 6.73 (m, 4, C 6 H 4 ), 8.86 (s, 1, C 7 --H).
EXAMPLE 19
6-[(4-Chloroanilino)methyl]-2,4-pteridinediamine (19)
Compound I (336 mg, 1.00 mmole) was added to a solution of 4-chloroaniline (383 mg, 3.00 mmoles) in DMAC (5 ml), and the resulting mixture was stirred under N 2 for 17 hrs and poured into H 2 O (25 ml). The yellow precipitate of crude hydrobromide was collected by filtration, washed with H 2 O, then Et 2 O and dried in vacuo (P 2 O 5 ). A suspension of the hydrobromide (339 mg) in H 2 O (30 ml) containing 1 N NaOH (1.80 ml) was stirred for 3 hrs. The yellow product was collected, washed with H 2 O, then Et 2 O, and dried at 100° in vacuo (P 2 O 5 ); yield 85% (255 mg), mp > 360° (Kofler Heizbank). Anal. Calcd for C 13 H 12 CIN 7 : C, 51.75; H, 4.01; N, 32.49. Found: C, 51.65; H, 4.15; N, 32.78. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (21.3), 290 (sh) (5.81), 237 (10.5), 350 (sh) (9.16); pH 7, 257 (33.1), 371 (7.86); 0.1N NaOH (unstable); pmr (DMSO-d 6 ), δ 4.44 (d, 2, CH 2 ), 6.46 (m, NH), 6.60, 7.73 (d, NH 2 ), 6.73 and 7.14 (m, 4, C 6 H 4 ), 8.72 (s, 1, C 7 --H).
EXAMPLE 20
6-[(N-Methylanilino)methyl]-2,4-pteridinediamine (20)
A solution of I (500 mg, 1.49 mmoles) and excess freshly distilled N-methylaniline (5 ml) in DMAC (20 ml) was stirred at about 25° for 48 hrs. The yellow solid that precipitated was collected by filtration, washed with cold DMAC and dried in vacuo (25°, P 2 O 5 ); yield 26% (110 mg). The solid was stirred for a few minutes with cold 0.5 M NaHCO 3 solution (25 ml), collected by filtration, and washed by centrifugation. Recrystallization from hot EtOH (50 ml) gave a fluorescent yellow powder; yield 7% (30 mg), mp 277°-268° dec. (Mel-Temp). Anal. Calcd for C 14 H 15 N 7 : C, 59.77; H, 5.38; N, 34.85. Found: C, 59.99; H, 5.47; N, 34.64. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 247 (15.5), 290 (sh), 337 (13.6), 350 (sh); pH 7, 257 (26.7), 371 (6.32); 0.1 N NaOH, 257 (27.2), 371 (6.61); pmr (DMSO-d 6 ), δ 3.10 (s, 3, CH 3 ), 4.68 (s, 2, CH 2 N), 6.88 (m, 7, NH 2 and C 6 H 5 ), 7.54 (s, 2, NH 2 ), 8.53 (s, 1, C 7 --H).
The filtrate from the 110 mg crop was evaporated to give a yellow residue which was washed thoroughly with Et 2 O and EtOH and then dried; yield 0.34 g. Treatment with NaHCO 3 solution and recrystallization from EtOH as described above gave additional 20, mp 258°-260° dec (Mel-Temp), in 57% yield (240 mg). Anal. Calcd for C 14 H 15 N 7 : C, 59.77; H, 5.38; N, 34.85. Found: C, 59.66; H, 5.30; N, 34.67.
EXAMPLE 21
6-[(Phenylamino)methyl]-2,4-pteridinediamine (21) Hydrobromide
Solid I (1.01 g, 3.00 mmoles) was added in 4 equal portions during 35 min (at intervals of sufficient time to allow the preceding portion to dissolve) to a stirred solution of freshly distilled aniline (1.11 g, 12.0 mmoles) and DMAC (20 ml) at 20°-25°. A clear solution formed soon after the last addition, and then, after about 5 min, crystalline product began separating. The mixture was stirred 22 hrs longer with the reaction flask purged with N 2 , stoppered, and protected from light. The collected yellow precipitate of 21.HBr was washed successively with cold H 2 O, Me 2 CO, and Et 2 O; yield 79% (0.82 g). Recrystallization from H 2 O (˜ 250 ml required) afforded pure 21.HBr in 38% yield (0.40 g). Anal. Calcd for C 13 H 13 N 7 .HBr: C, 44.84; H, 4.05; N, 28.16. Found: C, 45.09; H, 4.16; N, 27.96. Spectral data: .sub.λ max, nm(ε × 10 -3 ), 0.1 N HCl, 246 (18.4), 292-303 (plateau) (5.35), 336 (10.0), 350 (sh) (8.80); pH 7, 257 (27.2), 372 (7.24); 0.1 N NaOH, 257 (27.4), 372 (7.55); pmr (CF 3 CO 2 D), δ 5.28 (s, 2, CH 2 ), 7.6 (m, 5, C 6 H 5 ), 9.02 (s, 1, C 7 --H).
EXAMPLE 22
Dimethyl-N-[5-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]-pentanoyl]-L-glutamate (22) Hemihydrate
KOC 4 H 9 -t (6.55g, 58.4 mmoles) was added to a chilled solution containing I (4.91 g, 14.6 mmoles) and diethyl N-[5-(methylamino)pentanoyl]-L-glutamate hydrobromide (11.6 g, 29.2 mmoles) in DMAC (150 ml). The mixture was stirred at about 25° under N 2 in a closed flask protected from light for 19 hrs. The reaction mixture was filtered to remove insoluble matter, and the filtrate was evaporated in vacuo. The gummy residue was dissolved in MeOH (20 ml), and the solution was filtered and diluted with CHCl 3 (80 ml). This solution was applied to a silica gel column (450 g of Brickmann's Silica Gel H, Type 60), and the column was eluted with CHCl 3 :MeOH (4:1). According to tlc results all fractions that contained product contained also some unreacted starting ester. These fractions were combined and evaporated. The semisolid residue was stirred with EtOH (20 ml), and the yellow solid that formed was collected. Addition of Et 2 O (200 ml) to the filtrate gave more yellow solid, which was collected and washed with a little EtOH. The pmr and mass spectra of these two crops showed each to be the hydrobromide of the expected product; pmr (DMSO-d 6 ), δ 2.70 (s, 3, CH 3 N), 4.05 (pair of quartets, 4, OCH 2 ), 1.17 (t, 6, OCH 2 CH 3 ); m/e 490 (M + ). An unsuccessful attempt was made to dissolve this material in warm MeOH for column chromatography as before. The MeOH was evaporated in vacuo, and the yellow residue was suspended in EtOH (50ml). KOC 4 H 9 -t was added in portions until solution occurred. The KBr formed was removed by filtration, and the filtrate was evaporated. The residue was dissolved in CHCl 3 --MeOH (4:1, 50 ml), and the solution was applied to a silica gel column (120 g of Brickmann's Silica Gel H, Type 60). The column was eluted with 4:1 CHCl 3 --MeOH, the tlc-homogeneous fractions were combined and evaporated in vacuo. The yellow solid that remained was triturated with Et 2 O and dried in vacuo (25°, P 2 O 5 ); yield 12% (816 mg) of product which had undergone transesterification to the corresponding dimethyl ester. Anal. Calcd for C 20 H 30 N 8 O 5 .0.5H O: C, 50.95; H, 6.63; N, 23.76. Found: C, 50.97; H, 6.43; N, 23.91. Spectral data: pmr (DMSO-d 6 ), δ 1.26-2.44 [overlapping multiplets, 12, (CH 2 ) 4 CO and (CH 2 ) 2 CO], 2.16 (s, 3, CH 3 N), 3.56 (s, 3, CH 3 O), 3.60 (s, 3, CH 3 O), 3.64 (s, 2, CH 2 NCH 3 ), 4.27 (m, 1, NHCHCO). 8.18 (d, 1, CONH), 8.73 (s, 1, C 7 --H); mass spectrum, m/e 462 (M + ).
EXAMPLE 23
N-[5-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]pentanoyl]-L-glutamic Acid (23) Dihydrochloride Sesquihydrate
A solution of 22 (542 mg, 1.15 mmoles) in deaerated 0.1 N NaOH (92 ml) was stirred in the dark at about 25° in a closed flask under N 2 for 4 hrs. The solution was treated with 1 N HCl to produce pH 6 and diluted to 1 1. This solution was applied to a DEAE-cellulose column (4 × 25 cm; prepared from Mannex Regular Low Capacity DEAE-Cellulose by de-fining and deaerating) which had been treated with 0.5 M NaCl (1 1.), 0.5 NHCl (1 1.), 0.5 N NH 4 OH (1 1.), and H 2 O (6 1.). The uv absorbance of the column eluate was continuously monitored at 250 nm during application, washing, and elution. After application was complete, the column was washed with H 2 O (1.2 1.). The product was eluted with 0.02 N HCl, and its travel on the column could be observed by means of its blue fluorescence in uv light. The product-containing fractions, which were strongly uv absorbing, were pooled and lyophilized. The solid thus obtained was dissolved in 50 ml of water, and this solution was filtered and lyophilized. The product was faintly yellow, very light and fluffy; yield 89% (549 mg). Anal. Calcd for C 18 H 26 N 8 O 5 .2HCl .1.5H 2 O: C, 40.46; H, 5.85; N, 20.97; Cl, 13.27. Found: C, 40.49; H, 5.56; N, 20.80; Cl, 13.54. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl 246 (16.6), 297 (6.50), 337 (10.0), 348 (sh); pH 7, 225 (10.7), 262 (24.1), 373 (7.30); 0.1 N NaOH, 225 (12.1), 258 (24.3), 369 (7.50); pmr (DMSO-d 6 ), δ 1.4-2.4 [overlapping multiplets, 10, (CH 2 ) 3 CO and (CH 2 ) 2 CO], 2.78 (s, 3, CH 3 N), 3.18 (m, 2, NCH 2 CH 2 ), 4.20 (m, 1, NHCHCO), 4.69 (s, 2, PterCH 2 NCH 3 ), 8.22 (d, 1, CONH), 8.96 (s, 1, C 7 --H).
EXAMPLE 24
6-[(Phenethylamino)methyl]-2,4-Pteridinediamine (24)
Compound I (336 mg, 1.00 mmole) was added to a stirred solution of phenethylamine (970 mg, 8.00 mmoles) in DMAC (5 ml) at 0°, and the resulting suspension was stirred at 25° for 18 hrs and poured into H 2 O (25 ml). The crude product was collected by filtration, washed with H 2 O, dried in vacuo (100°, P 2 O 5 ) and redissolved in DMAC (8 ml). The solution was diluted with H 2 O (1 ml), stirred for 10 min, filtered and evaporated to dryness in vacuo. The residue of yellow solid was triturated with Et 2 O and dried in vacuo (100°, P 2 O 5 ); yield 59% (173 mg), mp about 219° dec (Kofler Heizback). Anal. Calcd for C 15 H 17 N 7 : C, 61.00; H, 5.80; N, 33.20. Found: C, 60.98; H, 5.84; N, 33.10. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 246 (16.4), 293 (sh) (5.23), 337 (9.70), 350 (sh) (8.5); pH 7, 225 (11.5), 261 (23.4), 373 (7.13); 0.1 N NaOH, 258 823.4), 371 (7.09); pmr (DMSO-d 6 ), δ 2.78 (s, 4, CH 2 CH 2 ), 3.90 (s, 2, PterCH 2 N), 6.57, 7.29 (d, 4, NH 2 ), 7.23 (s, 5, C 6 H 5 ), 8.72 (s, 1, C 7 --H).
EXAMPLE 25
6-[[3-(2-Ethoxyethoxy)propylamino]methyl]-2,4 -pteridinediamine (25)
A mixture of I (336 mg, 1.00 mmole) and 3-(2-ethoxyethoxy)propylamine (588 mg, 4.00 mmoles) in DMAC (5 ml) was stirred for 18 hrs, filtered, and evaporated to dryness in vacuo. A solution of the residue in MeOH (10 ml) was filtered and applied to two Brinkmann Silica Gel F-254 preparative thin-layer chromatography plates and developed with MeOH. The band of yellow product was extracted with hot MeOH and the extract evaporated to a solid which was triturated with Et 2 O (2 ml) and dried in vacuo (100°, P 2 O 5 ); yield 29% (95 mg), mp about 207° dec (Kofler Heizback). Anal. Calcd for C 14 H 23 N 7 O 2 .0.2H 2 O: C, 51.74; H, 7.26; N, 30.17. Found: C, 51.70; H, 7.34; N, 30.25. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 245 (16.1), 290 (sh) (5.18), 336 (9.75), 350 (sh) (8.46); pH 7, 225 (11.5), 261 (23.0), 373 (7.17); 0.1 N NaOH, 225(12.2), 257 (23.3), 370 (7.34); pmr (DMSO-d 6 ), δ 1.07 (m, 3, CH 3 ), 1.67 (m, 2, CH 2 CH 2 CH 2 ), 2.59 (m, NCH 2 CH 2 ), 3.40-3.64 (m, CH 2 O), 3.85 (s, 2, PterCH 2 N), 6.55, 7.60 (d, 4, NH 2 ), 8.74 (s, 1, C 7 --H).
EXAMPLE 26
6-[(Cyclohexylamino)methyl]-2,4-pteridinediamine (26) Hemihydrate
Solid I (2.77 g, 8.30 mmoles) was added in 4 equal portions during 1 hr to a stirred solution of cyclohexaneamine (2.45 g, 24.8 mmoles) in DMAC (33 ml). The mixture was stirred 21 hrs at 25° with the reaction flask purged with N 2 , stoppered, and protected from light. H 2 O (400 ml) was added to the stirred reaction mixture, and the solution (pH 9.7) quickly deposited a yellow solid which was removed by filtration after 10 min. A small additional amount of solid was removed after 15 min longer. These two solids were discarded. The solution was now flushed thoroughly with N 2 , and the pH of the solution was adjusted to 12 by the addition of 2 N NaOH. Gradual separation of yellow solid occurred during refrigeration for 45 min. The solid was collected, and the filtrate deposited more yellow precipitate over a period of one hour while N 2 was passed through the solution. The second crop of yellow solid was also collected. Both crops were washed with water and Et 2 O before being dried in vacuo (25°, P 2 O 5 ); total yield 46% (1.03 g). Anal. Calcd for C 13 H 19 N 7 .0.5H 2 O: C, 55.30; H, 7.14; N, 34.73. Found: C, 55.18; H, 7.14; N, 34.88. Spectral data: λ max , nm (ε × 10 -3 ), 0.1 N HCl, 245 (17.9), 283 (9.15), 336 (10.4), 347 (sh); pH 7, 261 (24.0), 372 (7.10); 0.1 N NaOH, 257 (23.9), 371 (7.27); pmr (DMSO-d 6 ), δ 0.8-2.0 (m, 10, cyclohexane CH 2 ), 2.40 (m, 1, NCH), 3.88 (s, 2, CH 2 N), 6.52 (s, 2, NH 2 ), 7.59 (s, 2, NH 2 ), 8.74 (s, 1, C 7 --H).
EXAMPLE 27
Diethyl N-[α-(2,4-diamino-6-pteridinyl)-4-anisoyl]-L-glutamate (27) Hemihydrate
A mixture of NaH (0.30 g of 50% dispersion in oil, 6.2 mmoles) and diethyl N-(4-hydroxybenzoyl)-L-glutamate (2.00 g, 6.20 mmoles) in DMAC (25 ml) was stirred under N 2 with ice-bath cooling until solution was complete and H 2 evolution had ceased. Solid I (1.04 g, 3.10 mmoles) was then added. The resulting dark-red solution was kept at about 25° under N 2 in a stoppered flask protected from light for 8 days. Addition to dilute HCl solution (150 ml of 0.01 N) gave an orange solid, which was collected by filtration, washed with H 2 O followed by Et 2 O, and dried in vacuo (25°, P 2 O 5 ); yield 70% (1.08 g). This material, which was used without further purification for conversion to 28, gave a well-resolved pmr spectrum consistent with the assigned structure. The only extraneous signal was that due to H 2 O of hydration; pmr (DMSO-d 6 ), δ 1.20 (m, 6, CH 3 ), 2.08 (m, 2, CHCH 2 CH 2 ), 2.40 (m, 2, CH 2 CH 2 CO), 3.46 (broad s, 2, H 2 O), 4.10 (m, 4, OCH 2 CH 3 ), 4.44 (m, 1, NHCHCH 2 ), 5.30 (s, 2, CH 2 OC 6 H 4 ), 6.74 (s, 2, NH 2 ), 7.16 and 7.90 (m, 4, C 6 H 4 ), 7.70 (broad s, 2, NH 2 ), 8.58 (d, 1, NHCH), 8.87 (s, 1, C 7 --H). The ir spectrum of the sample described is identical with that of a sample obtained from a trial run that gave the following elemental analysis results. Anal. Calcd for C 23 H 27 --N 7 O 6 .0.5H 2 O: C, 54.54; H, 5.57; N, 19.36. Found: C, 54.81; H, 5.77; N, 19.19.
EXAMPLE 28
N-[α-(2,4-diamino-6-pteridinyl)-4-anisoyl]-L-glutamic Acid (28) Monohydrate
The diethyl ester 27 (1.00 g) was dissolved with stirring in warm DMAC (15 ml). The dark-orange solution was cooled to 25°, and NaOH solution (40 ml of 0.1 N) was added in a thin stream. Cloudiness developed initially but soon cleared, and the solution was kept at 20°-25° under N 2 in a stoppered flask protected from light for 19 hrs. The solution was treated with Norit and filtered (Celite) to give a yellow-orange filtrate of pH 8.2. Careful treatment with 1 N HCl to produce pH 3.0 gave a yellow precipitate. After refrigeration (3 hrs.), the mixture was centrifuged, and the solid residue was washed twice with H 2 O (30-ml portions) with centrifugation followed by decantation. The solid was again suspended in H 2 O, collected by filtration, and dried in vacuo (25° over P 2 O 5 and NaOH pellets); yield 0.73 g. This sample produced a thin-layer chromatogram that revealed one migrating spot that fluoresced under uv light. A pale fluorescing spot remained at the origin. The sample was suspended in H 2 O (5 ml) and treated with NaOH solution (11 ml of 0.3 N) to redissolve. Clarification (Norit, Celite) was followed by addition of dilute HCl to pH 3.0. The precipitate was isolated as before and found by tlc to be homogeneous; yield 72% (0.65 g). Anal. Calcd for C 19 H 19 N 7 O 6 .H 2 O: C, 49.67; H, 4.61; N, 21.34. Found: C, 49.27; H, 4.23; N, 21.52. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 248 (32.2), 336 (11.2), 348 (sh) (10.0); pH 7, 260 (39.6), 370 (7.90); 0.1 N NaOH, 260 (40.0) 370 (8.21); pmr (CF 3 CO 2 D), δ 2.54 (m, 2, CHCH 2 CH 2 ), 2.83 (m, 2, CH 2 CO 2 H), 5.12 (m, 1, CHCO 2 H), 5.54 (s, 2, CH 2 OC 6 H 4 ), 7.24 and 7.94 (m, 4, C 6 H 4 ), 9.22 (s, 1, C 7 --H).
EXAMPLE 29
α-(2,4-Diamino-6-pteridinyl)-4-anisamide (29) Hemihydrate
Solid NaH (127 mg of 57% dispersion in mineral oil, 3.0 mmoles) was added to a solution of 4-hydroxybenzamide (412 mg, 3.00 mmoles) in DMAC (15 ml). When the evolution of H 2 was complete, solid I (504 mg, 1.50 mmoles) was added with stirring. After 141 hrs at about 25°, the reaction mixture was diluted with H 2 O (200 ml); the precipitate was collected by filtration, washed with petroleum ether and dried in vacuo (78°, P 2 O 5 ); yield 61% (293 mg), mp > 325° (Mel-Temp). This sample was homogeneous by tlc (CHCl 3 --MeOH, 5:1). Anal. Calcd for C 14 H 13 N 7 O 2 .0.5H 2 O: C, 52.51; H, 4.41; N, 30.61. Found: C, 52.41; H, 4.49; N, 30.87. Spectral data: λ max , nm (ε × 10 -3 ), 0.1 N HCl, 248 (25.8), 337 (10.3), 347 (sh) (9.37); pH 7, 260 (29.6), 371 (6.91); 0.1 N NaOH, 260 (30.0), 372 (7.55); pmr (DMSO-d 6 ), δ 3.36 (NH 2 and H 2 O), 5.28 (s, CH 2 O), 6.72 and 7.68 (NH 2 ), 7.50 (m, 4, C 6 H 4 ), 8.86 (s, 1, C 7 --H).
EXAMPLE 30
6-[(Phenoxy)methyl]-2,4-pteridinediamine (30)
Treatment of phenol with NaH followed by I in DMAC as described for 29 led to 30, mp about 285° dec (Mel-Temp), in 70% yield (283 mg from 1.50 mmoles of I) after a 72 hr reaction period. (The isolation procedure was the same as that given for 29.) The sample was homogeneous by tlc (CHCl 3 --MeOH, 5:1) except for a faint shadow near the origin. Anal. Calcd for C 13 H 12 N 6 O: C, 58.20; H, 4.51; N, 31.33. Found: C, 57.93; H, 4.26; N, 31.58. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 244 (17.7), 276 (5.26), 287 (5.32), 337 (10.4), 347 (sh) (9.35); pH 7, 260 (24.9), 372 (7.44); 0.1 N NaOH, 260 (25.1 ), 372 (7.58); pmr (DMSO-d 6 ), δ 5.22 (s, 2, CH 2 O), 6.69 (s, 2, NH 2 ), 7.64 (s, 2, NH 2 ), 7.15 (m, 5, C 6 H 5 ), 8.83 (s, 1, C 7 --H).
EXAMPLE 31
6-[(Phenylthio)methyl]-2,4-pteridinediamine (31) Hemihydrate
Solid I (1.50 mmoles) was added to a stirred, externally cooled (ice bath) mixture of anhydrous K 2 CO 3 (221 mg, 1.60 mmoles) and thiophenol (0.5 ml, approximately 5 mmoles) in DMAC (5 ml). The mixture was stirred at 20°-25° for 21 hrs. The yellow precipitate was collected, washed successively with Et 2 O and H 2 O, and dried in vacuo (78°, P 2 O 5 ); yield 87% (370 mg), mp 270°-272° dec (Mel-Temp). The product was homogeneous by tlc (CHCl 3 --MeOH, 5:1), Anal. Calcd for C 13 H 12 N 6 S.0.5H 2 O: C, 53.23; H, 4.47; N, 28.65. Found: C, 53.10; H, 4.09; N, 28.79. Spectral data: .sub.λ max, nm (ε × 10 -3 ), 0.1 N HCl, 247 (22.7), 342 (9.75); pH 7, 260 (26.4), 285 (sh) (8.90), 375 (8.07); 0.1 N NaOH, 260 (26.9), 286 (sh) (9.05), 376 (8.22); pmr (DMSO-d 6 ), δ 4.39 (s, 2, CH 2 S), 6.64 (s, 2, NH 2 ), 7.42 (m, 7, C 6 H 5 and NH 2 ), 8.67 (s, 1, C 7 --H).
It is noted that all temperatures given herein are in degrees centigrade.
It should now be apparent that the objects initially set forth have been successfully achieved. Moreover, while there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.
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A method for the preparation of pteridine compounds such as methotrexate is disclosed. 2,4-diamino-6-pteridine-methanol·HBr is reacted with triphenylphosphine dibromide or phosphorus tribromide to form 6-(bromomethyl)-2,4-diamino-pteridine hydrobromide and the bromine atom in the molecule is then replaced with the functional group, N-[4-(methylamino)-benzoyl]-L-glutamic acid in the case of methotrexate and N-(4-aminobenzoyl)-L-glutamic acid in the case of aminopterin.
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This application claims the benefit of priority from prior U.S. provisional application Ser. No. 60/221,165, filed Jul. 27, 2000.
This invention was made with Government support under DE-AR26-98FT40366 awarded by the United States Department of Energy. The Government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention relates to a device and method for conducting geotechnical and geoenvironmental measurements using direct push tools, and more particularly to a latching and retrieval system that allows the in situ interchange of several different tools including, but not exclusively, an electric cone penetrometer, a soil core sampler, a soil vapor sampler, and a grouting device, all through an embedded direct push rod string without requiring withdrawal of the string. The device also allows the collection and retrieval of soil core samples from multiple depths during a single penetration without requiring withdrawal of the rod string.
BACKGROUND OF THE INVENTION
Currently, the use of multiple direct push tools during a site characterization (i.e., piezocone, chemical sensors, core sampler, grouting tool) must be accomplished by withdrawing the entire penetrometer rod string to change tools. This practice results in multiple penetrations being required during characterization of a site, and to subsequently seal the resulting multitude of holes with grout.
SUMMARY OF THE INVENTION
The present invention allows multiple tools to be interchanged during a single penetration without withdrawing the rod string from the ground. This allows more work to be accomplished and reduces overall costs as time is not wasted pulling rods back out of the ground to change tools or retrieve soil core samples.
The implementation of a wireline tool approach to direct push technologies is unique from drilling implementations because in contrast to drilling (1) direct push incorporates direct sensing tools at the tip of the rod string, (2) direct push relies entirely on the transmission of axial force through instruments at the tip of the rod string to penetrate the earth, and (3) direct push tools are used to measure in situ stresses, electrical properties, the presence of chemical, and other properties as a means of characterization. Because of these differences direct push uses smaller diameter casings than drilling, with relatively greater wall thickness, and requires the accommodation of electrical cabling and/or optical fibers within the rod string.
The wireline system for multiple direct push tool usage of the present invention is composed of several components which are similar in function to conventional direct push and cone penetrometer technology (CPT) equipment used for in situ geoenvironmental. site characterization. Conventional equipment uses either a heavyweight push truck to advance tools into the earth under static load (cone penetration testing), or a percussion hammer approach using a lighter rig. The electronic probes are instrumented and signals are transmitted to the surface via electrical cable and/or fiber optics strung through the center of the hollow push rods. Also typical is the simple collection of multiple soil core samples.
With the wireline system of the present invention, the same method is used to advance the rod string into the earth. However, in the present invention, the first rod (i.e., the deepest one) has a provision for a latching mechanism that allows various tools to be locked into and unlocked from the rod string, as well as retrieved and deployed through the rod string while the rod string remains embedded in the ground. This system allows instrumented probes and samplers, as well as other tools, to be used during a single penetration.
The wireline system consists of six major components:
rods,
latching mechanism,
soil core sampler,
piezocone module,
vapor sampler, and
grout module.
Rods: The push rods have a relative wall thickness (about 19% of the diameter) exceeding that a typical drive casings used with drilling technologies because direct push systems do not rely on rotary action, cutting bits, or augers to remove material from the path of the rod string, and thus must support the transmission of greater axial load relative to casing diameter than drilling systems in order to penetrate the earth. Typical direct push rod diameters range from about one inch to two and a quarter inches.
The wireline rod string of the present invention has a two-inch outer diameter and a one and one-quarter inch inner diameter. The shouldered joints of the one-meter rod segments are joined by double-lead rope threads which connect faster and sustain greater loading than V-threads.
The rod string optionally incorporates occasional rod expanders (one on every fifth or sixth rod in the string). Expanders are rings welded to the outside of the rods which widen the borehole beyond the normal outside diameter of the rod segments as they pass into the earth, thus creating an annular void between the earth and the normal outer rod surface which alleviates sidewall friction that can accumulate along the embedded length of the rod string. By this action, the expanders enable deeper penetration in some soils than would be achievable without them when using the system.
Latching Mechanism: The latching mechanism comprises two main components, one stationary and the other removable. The stationary component is also the lowermost push rod segment. It is a specialized segment called the tool housing which embodies the receiving mechanism for the removable element. The removable element is the lock assembly.
The lock assembly employs two horizontally opposed, hinged locking dogs which lock the tools into place by rotating outward to occupy a receiving groove in the inside surface of the tool housing. The dogs are held in the locked position by a locking wedge which slides vertically between them. This dog arrangement allows the axial stress on the direct push tools from application of static force, rapid percussion, or other dynamic loading to be distributed over a greater bearing area than on systems used in conventional drilling.
This fulfills the unique requirement of the direct push application for more bearing capacity than required in wireline drilling arrangements because direct push tools encounter the stress of penetration, which must be transferred to the rod string, whereas with drilling, less axial stress is generated on the tools and the outer casing carries most of the bearing load directly. When the locking dogs are in the engaged position, a spring-loaded locking wedge rests between them, preventing retraction of the dogs.
A retraction system allows disengagement of the locking dogs in the latching mechanism by displacement of a spring-loaded locking wedge which travels vertically between the dogs and has a conic outer surface at its base, a cylindrical outer surface above the conic surface, and a smaller diameter shaft above that. The dogs have a vertical inner surface that is beveled at the top, such that when the dogs are not engaged, the wedge must be in a raised position with its conic surface acting against the complementary beveled surface on the dogs, but when the dogs are engaged, the wedge is in a lower position with its vertical surface acting against a vertical surface on the interior of the dogs.
The nature of the contact between the wedge and the dogs disallows retraction of the dogs when the vertical surfaces are in contact, regardless of the inward force exerted on the dogs by the receiving groove, but allows the dogs to retract in response to inward force when the wedge has been raised enough that the conic surfaces are in contact. When not counteracted for retrieval, a compression spring around the shaft of the locking wedge keeps the wedge in the downward position.
The lock mechanism allows the deployed tool to lock into place upon reaching an appropriate depth. A landing nut allows free fall deployment of tools, fine tuning of lock clearances, and easy replacement of the most wear-receiving parts.
The tool housing is a specialized version of the individual rods segments that compose the rod string. First, it is shorter than the one-meter length of the other rods. Second, while the inner diameter of most of the tool housing is identical to that of the individual rods in the string, the tool housing adds a receiving groove of wider diameter than the rod inner diameter, and an interior threaded section which holds the landing nut of lesser inner diameter than the rods.
In the retracted position, the outer surface of the dogs is contained within a smaller diameter than the interior of the rods, but larger than the inner diameter of the landing nut, so the landing nut stops the dogs from overshooting the receiving groove and keeps tools from overextending beyond the bottom of the rod string. The nut also provides the ability to adjust the receiving groove size so that the fit of the locking dogs can be fine-tuned. The system is designed such that the nut receives the impact of falling tools, and is easily replaced if wear becomes an issue.
A compression spring surrounds the shaft of the locking wedge. This spring causes the locking wedge to exert an outward force on the locking dogs whenever they are partially or fully retracted. This outward force has several advantages. First, it causes instant extension of the dogs into the engaged position when the receiving groove in the tool housing is encountered. Second, it keeps tools centered in the rod string as they are lowered down to the tip for deployment. There is always an outward component of force on the locking dogs, whenever they are not fully extended and the retrieval wire is free of tension.
The chamfered lower edge of the locking dogs allows them to skate over discontinuities and imperfections in the interior rod surface, such as where joints occur in the rod string. The action of the dogs as they skate down the interior surface of the rods also results in cleaning of the surface,.by scraping impurities from the surface and allowing them to drop out the open bottom of the rod string.
Finally, once the dogs are engaged in the receiving groove, the spring-loading of the locking wedge prevents vertical displacement of the wedge from between the locking dogs that would allow the dogs to retract and disengage under the rod acceleration induced by vibratory or percussion driving. The wedge also has a hole through the center to allow the pass-through of electrical wiring, a grout tube, or optical fibers to the tools below.
Tools are retrieved by pulling up a retrieval wire attached to the locking wedge by a connector block. This removes the locking wedge from between the dogs and allows the dogs to retract under the load of the tool pushing the dogs against the upper, beveled surface of the receiving groove. Tools are redeployed by lowering them down the rod string using the retrieval cable until they come to rest against the landing nut, and the dogs snap into place in the tool housing.
Piezocone: The piezocone tool incorporates standard gauges for tip stress, sleeve stress and pore pressure. The system is designed such that the piezocone can be lowered down the rod interior and locked into place. Once locked in place the piezocone and the rod can be advanced together.
The system is capable of unlocking the probe at any depth for installation of either a dummy tip, another probe, or the grouting tool. The wireline piezocone tool is 1.125 inches in diameter. This diameter corresponds to a 6.5 cm 2 projected cone area.
The piezocone maintains appropriate ratios of sleeve area to tip area. The probe mandrel and probe body are sized relative to each other such that if sufficient bending stress to break the tool were developed in the subsurface during deployment, the probe would fail at the mandrel rather than at the body, thus minimizing the potential for damage to other wireline system components.
Soil Sampler: The soil sampler tool allows the collection and retrieval of core samples from multiple depths during a penetration without requiring retraction of the CPT rods from the ground. The sample barrel produces a one-inch diameter, 12-inch long core of soil, accommodates the use of a plastic retainer basket (for loose soils), and is easily separable from the locking mechanisms and basket retainer nut. Either end of the barrel connects to these other parts, or to end plugs used for sealing the sample. The nut used to hold in the retainer basket receives the tip soil stress and prevents wear or damage to the leading edge of the core barrel.
Grouting Module: The system includes a grouting module to permit grouting a penetration upon retraction of the rod string, such that the entire void created by the penetration process is filled with grout. The tool allows the grout to flow from the down-hole end of the rod string during retraction to ensure that the entire void created by the penetration process is filled with grout. This approach to grouting meets the regulatory guidelines of most Environmental Protection Agency (EPA) regional offices.
Tubing is used to transport the grout from the pump to the grouting tool at the end of the rod string. The grouting tool locks in place at the end of the down-hole end of the push rods and is interchangeable with the piezocone and other tools.
Prior to the present invention, the use of multiple characterization tools at a single location during a direct push investigation required typically at least 100% (1×) re-penetration (for grouting) and as much as 2000% (20×) re-penetration (for collecting continuous soil core samples).
The manner in which the invention allows multiple tools to be used in a single penetration and allows the retrieval of several soil core samples during a single penetration without withdrawing the rods results in a remarkable time savings for continuous sampling activities. In most cases, it will completely eliminate the incidence of re-penetration. Data from field demonstrations of the invention have indicated time savings of up to 75% for a typical characterization. Once the penetration has begun, a typical one-foot direct push wireline soil sample can be collected every two to three minutes, whereas conventional direct push soil sampling averages about 10 to 15 minutes per foot.
Additionally, it is a requirement of some environmental regulators that the borehole created by a CPT sounding or collection of samples in a contaminated area be sealed with grout upon retraction of the borehole casing. This has prohibited the application of direct push technology in some areas, whereas the present invention allows grouting upon retraction by exchange of the characterization tools with the grouting tool. The ability to place grout in the same hole upon withdrawal also eliminates the possibility of creating a new hole when a hole has to be repenetrated to complete a grouting operation.
Although the use of wireline tools in conjunction with drilling for subsurface characterization has been well established, applying wireline concepts to direct push technology is novel and unique from drilling implementations. In contrast to drilling, direct push technology (1) usually incorporates direct sensing tools at the tip of the rod string, (2) subjects the tools at the tip of the rod string to greater axial force that must be transferred to the rod string, in order to penetrate the earth, and (3) direct push tools are used to measure in situ stresses, electrical properties, the presence of chemical, and other properties as a means of characterization during penetration. Because of these differences direct push typically uses smaller diameter casings than drilling, with relatively greater wall thickness, and requires the accommodation of electrical cabling and/or optical fibers within the rod string. The use of semicircular locking dogs, to evenly distribute around the circumference of the rod the load transferred between the tools and the rod string, while allowing a hollow center for passing cables through is a unique advantage.
Another advantage of the latch design of a locking dog geometry is that it transforms axial load on the dogs to a radial compression load on the locking wedge. This removes load from the hinge pins and averts the need for parts with large cross-sectional areas to resist shear loads.
Because direct push technology is relatively new and offers many significant advantages over drilling for environmental characterization even without the use of wireline tools, few practitioners of the direct push technology recognize the potential for time saving and cost saving afforded by this approach.
Direct push systems incorporate rods that are relatively small diameter relative to drilling tools. Due to the size constraints of conducting mechanical latching operations inside a direct push rod, how to successfully develop a wireline system for multiple direct push tool usage has not been readily apparent to practitioners in the art.
Accordingly, it is an object of the present invention to use a direct push rod string for the measurement of soil parameters through the use of a series of replaceable measurement modules which are lowered through the rod string and locked in a tool housing in a leading end of the rod string and which can be released from the tool housing and withdrawn through the rod string for replacement with a different soil measuring module.
It is another object of the present invention to use a direct push rod string for the measurement of soil parameters through the use of a series of replaceable measurement modules which are lowered through the rod string and locked in a tool housing in a leading end of the rod string and which can be released from the tool housing and withdrawn through the rod string for replacement with a different soil measuring module by the use of a latching mechanism for securing the measurement module in the tool housing by two opposed locking dogs engaged by a locking wedge to force the dogs into a receiving groove on the interior surface of the tool housing and biasing the locking wedge for forcible retraction of the locking wedge by a wireline and allowing retraction of the dogs from the receiving groove for withdrawal of the measurement module or probe.
It is still yet another object of the present invention to use a direct push rod string for the measurement of soil parameters through the use of a series of replaceable measurement modules which are lowered through the rod string and locked in a tool housing in a leading end of the rod string and which can be released from the tool housing and withdrawn through the rod string for replacement with a different soil measuring module by the use of a latching mechanism for securing the measurement module in the tool housing by two opposed locking dogs engaged by a locking wedge to force the dogs into a receiving groove on the interior surface of the tool housing and biasing the locking wedge for retraction of the locking wedge by a wireline and allowing retraction of the dogs from the receiving groove for withdrawal of the measurement module with the locking dogs being chamfered on a lower edge to allow the dogs to skate over discontinuities in the rod string and having a chamfered upper edge to assist in retraction of the dogs from the receiving groove upon release of the dogs by the locking wedge.
These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of the wireline system of the present invention illustrating a wireline piezocone module in a locked position in a tool housing.
FIG. 2 is a cross-sectional view taken along line 2 — 2 of FIG. 1 .
FIG. 3 is a sectional view of the wireline system of the present invention with a wireline piezocone module in an unlocked position so as to slide with respect to the tool housing.
FIG. 4 is a cross-sectional view taken along line 4 — 4 of FIG. 3 .
FIG. 5 is a schematic illustration of the latching mechanism in the locked position within a portion of the tool housing.
FIG. 6 is a cross-sectional view taken through the locking dogs in FIG. 5 .
FIG. 7 is a schematic illustration of the latching mechanism in an unlocked position and partially withdrawn from the tool housing.
FIG. 8 is a cross-sectional view taken through the locking dogs of FIG. 7 .
FIG. 9 is a side view of the leading section of the rod string (also called the tool housing), with the threading at opposite ends being illustrated in dotted lines.
Figure 10 is a cross-sectional view of the section of the rod string shown in FIG. 9 .
FIG. 11 illustrates a section of a measurement probe having a lock mechanism for securing the measurement probe within the tool housing of a rod string.
FIG. 12 is an exploded view of the lower portion of the lock mechanism shown in FIG. 11 .
FIG. 13 is a cross-sectional view of the lock assembly illustrating the projection of the locking wedge dogs as forced radially outwardly by opposed locking wedge flanges.
FIG. 14 is a cross-sectional view of a piezocone measuring module for insertion into the tool housing after passing through the rod string of the present invention.
FIG. 15 is a cross-sectional view of a grout module assembly to be lowered into the tool housing after passing through the rod string of the present invention.
FIG. 16 illustrates a soil sampler mounted on the latch mechanism of the present invention to be lowered into the tool housing after passing through the rod string of the present invention.
FIG. 17 is a side view of the connector block used in FIGS. 1, 3 , 11 and 13 to interconnect the wireline with the lock mechanism.
FIG. 18 is an end view of the connector block of FIG.
FIG. 19 is an opposite end view of the connector block shown in FIG. 17 .
FIG. 20 is a sectional view taken along line 20 — 20 of FIG. 18 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
With reference to the drawings, in general, and to FIGS. 1 through 4, in particular, a wireline system for multiple direct push tool usage embodying the teachings of the subject invention is generally designated as 20 . With reference to its orientation in FIG. 1, the wireline system includes a rod string 22 including a plurality of assembled rod sections 22 a , 22 b , 22 c , etc., which progressively extend upwards to ground level. The lowermost sections of the rod string 22 form a tool housing including a receiving mechanism for a removable element such as a soil core sampler, a piezocone module, a vapor sampler and a grout module, to name a few.
In FIG. 1, a piezocone module 24 for measuring tip stress, sleeve stress and pore pressure is shown projecting approximately 27 cm beyond the leading cutting mouth end of the rod string when locked in a deployment position. The piezocone module 24 is connected to a lock mechanism 28 for engaging with a receiving groove 30 on an interior surface of the tool housing, as a shown in the sectional view of FIG. 2 . Opposed locking dogs 32 a , 32 b extend into the groove 30 to maintain a position of the piezocone module with respect to the rod string.
In FIGS. 3 and 4, the opposed locking dogs 32 a , 32 b have been retracted out of the receiving groove 30 and the piezocone module 24 is retracted through the rod string 22 so that the cone or tip 34 of the piezocone module is positioned upstream of the leading end 26 of the rod string. The retraction of the piezocone module 24 through the rod string is caused by a pulling force on the wireline 36 from above ground. The wireline is anchored within block 38 , within which one end of locking wedge 40 is also mounted. Upward movement of the wireline against a bias force pulls locking wedge 40 upward and releases a radially outward force on the locking dogs 32 a , 32 b.
As shown in greater detail in FIGS. 5 through 8, a representative portion of the tool housing 42 is shown. At an uppermost portion of the measurement module to be inserted into the tool housing, whether it is a piezocone module, soil core sampler, vapor sampler, grout module or other testing sampler or module, is located a lock housing 44 . Pivotally mounted on the lock housing 44 by pins 46 a , 46 b are locking dogs 32 a , 32 b . Slidably mounted between the locking dogs 32 a , 32 b is a locking wedge 48 which is hollow and is biased in the direction of arrow 50 by a spring (not shown).
The hollow interior of the locking wedge is used for passage through of optical cable or other instruments such as a multi-conductor cable. The construction of the block connector 38 in FIGS. 1 and 3, shown in FIGS. 17-20, includes a passageway 38 a feed optical cable 200 (FIG. 13) or other instruments around wireline 36 , through block connector 38 , through locking wedge 40 and beyond the lock mechanism 28 .
Connector block 38 includes threaded passageway 39 for receipt of a threaded end of the locking wedge. The opposite end includes a threaded opening 41 for receipt of a threaded end of the wireline.
When the locking wedge is positioned as shown in FIG. 5, the dogs are prevented from further movement downward by engagement of the dogs with a landing nut 52 projecting into the interior of the tool housing 42 . The movement of the locking wedge between the locking dogs causes engagement of a chamfered leading edge 54 of the locking wedge with a chamfered edge 56 a , 56 b of the locking dogs. In the positioning of the locking wedge between the locking dogs 32 a , 32 b , the locking dogs project radially outward into a receiving groove 58 of the tool housing.
When the locking wedge 48 is moved against the bias force indicated by arrow 50 as shown in FIG. 7, the module or sampler is capable of being pulled by a wireline to force the locking wedge from between the locking dogs 32 a , 32 b . Chamfered edges 60 a , 60 b of the locking dogs slide along chamfered edge 62 of receiving groove 58 to swing about pivot pins 46 a , 46 b and move radially inward so as to be released from within the receiving groove 58 . The module or sampler is thereby allowed to be retracted by the wireline and removed from the rod string. Another measurement or sampler module is then lowered through the rod string by a wireline until its locking mechanism engages within the receiving groove of the tool housing as shown in FIG. 5 . The insertion of a new measurement or sampler module may be done after or during further advancement of the rod string to a different depth.
In FIGS. 9 and 10, a section of the rod string 64 is shown having female rope threaded portions 66 and 68 as shown in detail in FIG. 10 . The rope threading 68 includes further threading 68 b . Corresponding male threaded sections of the rod string are interengaged with the female threaded sections to extend the overall length of the rod string being pushed into the ground.
FIGS. 11 and 12 illustrate a locking mechanism for connection to a measurement or soil sampler module having locking dogs 32 a , 32 b being pivotally mounted in tool housing 42 by pins 46 a , 46 b with locking wedge 48 extending between the pins and the locking dogs. Block connector 38 is shown having wireline 36 projecting therefrom for retraction and lowering of a measurement or soil sampler module.
In FIG. 12, the exploded view shows the details of the locking wedge 48 with a surrounding compression spring 70 . The compression spring is retained between a flange 72 a adjacent to the lowermost end of the locking wedge and a washer 72 and a retaining ring 74 at an upper end of the locking wedge.
Examples of other measurement or soil sampler modules are shown in FIGS. 13 through 16. In FIG. 13, a lock mechanism 40 , including locking dogs 32 a , 32 b , locking wedge 48 , compression spring 70 , tension spring retaining washer 72 and tension spring retaining ring 74 are shown. In addition, pivot pins 46 a , 46 b are used to allow the pivoting of the locking dogs. Connector block 38 and wireline 36 are also shown. A leading end 80 of the latching mechanism is used to secure the latching mechanism to a measurement or soil sampler modular probe as shown in FIGS. 14, 15 and 16 .
In FIG. 14, a piezocone module 24 is shown having tip 34 , filter 82 , O-rings 84 , retainer ring 86 , mini-piezo gauge housing 88 , mini-piezo gauge 90 , load cell sleeve 92 , friction sleeve 94 , spring ring 96 , cable nut 98 , male connector 100 , cone connector ring 102 , cone connector housing 104 and cone connector plug 106 . The internal threading 108 is connected to the end 80 of the lock mechanism 40 for passing through the rod string to the position shown in FIGS. 1 and 3.
Similarly, a grout module 110 may be lowered by connection of the internal thread 112 , secured to the end 80 of the lock mechanism 40 . The grout module 110 includes a disposable grout tip 114 sealed by an O-ring 116 . Hollow nylon tubing 118 extends through the hollow interior of the connected lock mechanism as well as the hollow internal cavity of the locking wedge and by connection with a hose barb union 120 , to a further length of nylon tubing 122 . Grout is passed through the latching mechanism to the grout module when the hole of the rod string is to be sealed by grout upon withdrawal of the grout module from the rod string.
By similar connection to the lock mechanism, a soil core sampler 130 , as shown in FIG. 16, or vapor sampler, for example, may be lowered into the rod string and removed by the wireline connected to the lock mechanism. A plurality of different samplers or modules may thereby be lowered into or removed from a single rod string to achieve multiple testing through a single bore hole.
The foregoing description should be considered as illustrative only of the principles of the invention. 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 tool latching and retrieval system allows the deployment and retrieval of a variety of direct push subsurface characterization tools through an embedded rod string during a single penetration without requiring withdrawal of the string from the ground. This enables the in situ interchange of different tools, as well as the rapid retrieval of soil core samples from multiple depths during a single direct push penetration. The system includes specialized rods that make up the rod string, a tool housing which is integral to the rod string, a lock assembly, and several tools which mate to the lock assembly.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/792,873, filed Feb. 23, 2001, entitled “Storage Area Network Using A Data Communication Protocol,” and is also a continuation-in-part of U.S. patent application Ser. No. 09/925,976, filed Aug. 9, 2001, entitled “System And Method For Computer Storage Security,” the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention concerns “port spoofing,” which allows a computer to “fail over” to its secondary fibrechannel connection if its primary fibrechannel connection should fail.
[0003] Fibrechannel is a network and channel communication technology that supports high-speed transmission of data between two points and is capable of supporting many different protocols such as SCSI (Small Computer Systems Interface) and IP (Internet Protocol). Computers, storage devices and other devices must contain a fibrechannel controller or host adapter in order to communicate via fibrechannel. Unlike standard SCSI cables, which can not extend more than 25 meters, fibrechannel cables can extend up to 10 km. The extreme cable lengths allow devices to be placed far apart from each other, making it ideal for use in disaster recovery planning. Many companies use the technology to connect their mass storage and backup devices to their servers and workstations.
[0004] In addition to being able to protect data through disaster recovery plans and backup, another requirement for a computer data communications network is that the storage devices must always be available for data storage and retrieval. This requirement is called “High Availability.” High Availability is a computer system configuration implemented with hardware and software such that, if a device fails, another device or system that can duplicate the functionality of the failed device will come on-line to take its place automatically and transparently. Users will not be aware that a failure and switch-over had taken place if the system is implemented properly. Many companies cannot afford to have downtime on their computer systems for any length of time. High availability is used to ensure that their computer systems remain running continuously in the event of any device failure. Servers, storage devices, network switches and network connections are redundant and cross-connected to achieve High Availability. FIG. 1 shows a typical prior art fibrechannel High Availability configuration.
[0005] In the configuration of FIG. 1, High Availability is achieved by first creating mirrored storage devices 145 and 150 and then establishing multiple paths to the storage devices which are represented by the fibrechannel connections 105 , 110 , 125 , 130 , 135 , and 140 . This configuration allows the server 100 to continuously be able to store and retrieve its data, even if multiple failures have occurred, as long as one of its redundant hardware components or fibrechannel connections does not fail. For example, if paths 110 and 125 fail, the data traffic will be routed through paths 105 and 140 to access storage device 150 . Special software must be running on the server to detect the failures and route the data through the working paths. The software is costly and requires valuable memory and CPU processing time from the server to manage the fail-over process.
SUMMARY OF THE INVENTION
[0006] The present invention is a system and method of achieving High Availability on fibrechannel data paths between an appliance's fibrechannel switch and its storage device by employing a technique called “port spoofing.” This system and method do not require any proprietary software to be executing on the file/application appliance other than the software normally required on an appliance, which includes the operating system software, the applications, and the vendor-supplied driver to manage its fibrechannel host adapter(s).
[0007] The invention includes a system for appliance back-up, in which a primary appliance is coupled to a network, whereby the primary appliance receives requests or commands and sends a status message over the network to a standby appliance, which indicates that the primary appliance is operational. If the standby appliance does not receive the status message or the status message is invalid, the standby appliance writes a shutdown message to a storage device, which is also coupled to the network. The primary appliance then reads the shutdown message stored in the storage device and disables itself from processing requests or commands. Preferably, when the primary appliance completes these tasks, it disables communication connections and writes a shutdown completion message to the storage device. The standby appliance reads the shutdown completion message from the storage device and initiates a start-up procedure, which includes causing the address of the standby appliance to be identical to the primary appliance address and processing the requests or commands in place of the primary appliance. The primary appliance can include a fibrechannel adapter having associated therewith the primary appliance address, and the standby appliance can have a fibrechannel adapter having associated therewith the standby appliance address. The standby appliance can include a standby application, which is identical to a primary application in the primary appliance, for processing the requests or commands.
[0008] The invention also includes a method for appliance back-up, which includes sending a status message from a primary appliance to a standby appliance indicating that the primary appliance is operational. If the standby appliance does not receive the status message or the status message is invalid, a shutdown message is written to a storage device. The primary appliance reads the shutdown message stored in the storage device and is disabled from processing requests or commands. The disabling of the primary appliance can include completing tasks, disabling communication connections, and writing a shutdown completion message to the storage device. The standby appliance reads the shutdown completion message from the storage device and initiates a start-up procedure so that a standby application, included in the standby appliance, can process the requests or commands. A standby appliance address is changed to the primary appliance address and the standby appliance processes the requests or commands.
[0009] Another method for appliance back-up is disclosed which includes monitoring a primary appliance for an indication of a failure, the primary appliance having a primary appliance address. If the failure occurs, a message is written to a storage device and, in response, the primary appliance is disabled from processing requests or commands. The failure can be the primary appliance not sending the status message to a standby appliance. The standby appliance has a standby appliance address, which is changed to the primary appliance address so the standby appliance can processes the requests or commands. The standby appliance address and the primary appliance address are world wide port names. The monitoring can include sending a status message to the standby appliance indicating that the primary appliance is operational, or sending a status request message to the primary appliance and receiving an update status message from the primary appliance. The failure message is written if the standby appliance does not receive the status message or if the status message is invalid. Alternatively, the message is written if the standby appliance does not receive the update status message or the update status message is invalid. The disabling can include completing tasks, disabling communication connections, writing a shutdown completion message to the storage device (by the primary appliance), reading the shutdown completion message from the storage device (by the standby appliance), and initiating a start-up procedure. The standby appliance can include a standby application, which is identical to a primary application in the primary appliance, for processing the requests or commands.
[0010] One of the primary advantages of the present invention is that additional software is not required to be running on the file/application server. Many system administrators prefer to only install the software that is necessary to run their file/application servers. Many other solutions require special software or drivers to run on the server in order to manage the fail-over procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of preferred embodiments, taken together with the accompanying drawings, in which:
[0012] [0012]FIG. 1 is a block diagram of a prior art fibrechannel High Availability network configuration;
[0013] [0013]FIG. 2 is a block diagram of the network configuration of the present invention;
[0014] [0014]FIG. 3 is a detailed block diagram of FIG. 2;
[0015] [0015]FIG. 4 is a block diagram showing a failed health monitor connection and the method used to send a shutdown signal;
[0016] [0016]FIG. 5 is a flowchart showing the actions of the primary appliance and the standby appliance when the health monitor link or primary appliance is non-functional;
[0017] [0017]FIG. 6 is a flowchart showing the actions of the standby appliance to become active; and
[0018] [0018]FIG. 7 is a block diagram showing more than one standby appliance.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The present invention is based on a software platform that creates a storage area network (“SAN”) for file and application servers to access their data from a centralized location. A virtualized storage environment is created and file/application servers can access its data through a communication protocol such as Ethernet/IP, fibrechannel, or any other communication protocol that provides high-speed data transmissions. Fibrechannel is the protocol that will be discussed herein, although it is understood that the other previously mentioned communication protocols are also within the scope of the present invention.
[0020] As mentioned before, computers, storage devices and other devices contain a fibrechannel (FC) controller or host adapter in order to communicate via fibrechannel. In the present invention, FC hubs/switches are used to connect file/application servers to servers that manage the storage devices. Storage devices can be RAID (redundant array of independent disks) subsystems, JBODs Oust a bunch of disks), or tape backup devices, for example. An FC switch allows a server with a fibrechannel host adapter to communicate with one or more fibrechannel devices. Without a hub or switch, only a point-to-point or direct connection can be created, allowing only one server to communicate with only one device. “Switch” thus refers to either a fibrechannel hub or switch.
[0021] Fibrechannel adapters are connected together by fiber or copper wire via their FC port(s). Each port is assigned a unique address called a WWPN or “world wide port name.” The WWPN is a unique 64-bit identifier assigned by the hardware manufacturer and is used to establish the source and destination between which data will travel. Therefore, when an FC device communicates with another FC device, the initiating FC device, or “originator,” must use the second FC device's WWPN to locate the device and establish the communication link.
[0022] Fibrechannel devices that are connected together by an FC switch communicate on a “fabric.” If a hub is employed, then the communication link is called a “loop.” On a fabric, devices receive the full bandwidth when they are communicating with each other, and on a loop the bandwidth is shared.
[0023] Although the manufacturers assign WWPN addresses, the addresses are not permanently fixed to the hardware. The addresses can be changed. Software can programmatically change the WWPN addresses on the fibrechannel hardware. The present invention employs this feature by changing the WWPN address on a standby FC adapter to the WWPN address used by the failed FC adapter.
[0024] The present invention employs storage management software that is capable of running within any kind of computing device that has at least one CPU and is running an operating system. Examples of such computing devices are an Intel®-based PC, a Sun® Microsystems Unix® server, an HP® Unix® server, an IBM® Unix® server or embedded systems (collectively referred to as “appliances”). The software performs the writing, reading, management and protection of data from its file/application servers and workstations, and is disclosed with more specificity in U.S. patent application Ser. No. 09/792,873, filed Feb. 23, 2001, the disclosure of which has already been expressly incorporated herein by reference. One of the protection features of the software is the ability to “fail over” to another appliance if a set of defined failures occurs. The failures are defined and discussed in the following paragraphs.
[0025] More specifically, the present invention creates a transparent secondary path for data to flow in the event that a primary data path to a storage device or storage server managing the primary path fails for any reason. The secondary path is a backup communication link to the same storage device. Each computer contains at least one FC host adapter connected to one FC switch. This operation is shown in FIG. 2, which includes SAN client 200 , FC switch 210 , storage server A 225 , storage server B 230 , and storage device 250 . Attached to each storage server is an FC adapter—primary FC adapter 216 is attached to storage server A 225 and standby FC adapter 217 is attached to storage server B 230 . (There is also an FC adapter, not shown, attached to SAN client 200 .) The primary data path consists of paths 205 , 215 , and 240 , and the transparent secondary data path consists of paths 220 and 245 . The secondary path 220 is a backup communication link to storage device 250 . If primary path 215 fails, storage server B 230 detects the failure and initiates its standby FC adapter 217 to begin “spoofing” primary FC adapter 216 by copying its identity and causing SAN client 200 to function with standby FC adapter 217 in place of primary FC adapter 216 . Data then flow through backup FC connection 220 , through standby FC adapter 217 , into storage server B 230 , and then to connection 245 to storage device 250 .
[0026] [0026]FIG. 3 shows a more detailed view of FIG. 2. Two appliances, a primary appliance 525 and a standby appliance 530 are running the above-described software. The appliances can be computers, for example, personal computers, servers, or workstations. Standby appliance 530 is a fail-over appliance. The two appliances 525 , 530 are connected to the same storage device 550 and to FC switch 510 . The storage device 550 can be any kind of device that stores data important enough to require protection from failure such as a hard disk, a RAID system, a CDROM, or a tape backup device. SAN client 500 , which is a file/application server or workstation, is configured with two separate data paths, a primary path made up of paths 515 and 540 , and a standby path, made up of paths 520 and 545 . Paths 515 and 520 always use a fibrechannel medium/protocol, but paths 540 and 545 may use fibrechannel, or may use a different medium/protocol such as SCSI, IDE (Integrated Drive Electronics) or any other storage medium/protocol. Although one SAN client is shown in the example of FIG. 3, in an actual production configuration, a primary appliance may manage the storage needs for multiple SAN clients. Data are actively transmitted bi-directionally over primary data paths 515 , 540 between SAN client 500 , primary appliance 525 and storage device 550 (as long as primary appliance 525 and its paths 515 and 540 remain in good working order). No data will be transmitted bidirectionally over standby paths 520 , 545 between SAN client 500 and storage device 550 . However, standby appliance 530 may or may not be data active (i.e., ready to receive or receiving data from the SAN client) depending on its configuration.
[0027] This standby appliance 530 can be implemented strictly as a fail-over appliance for one or more primary appliances. If its only function is to standby, then standby appliance 530 must wait for one of the primary appliances to fail so that it can become data active. If a standby appliance 530 is a fail-over appliance for more than one primary appliance 525 , then it must contain one dedicated standby FC adapter 517 for each primary appliance 525 , and it must have a dedicated connection to each storage device 550 that it might need to manage. Standby appliance 530 itself can also be a primary appliance to its own set of SAN clients and storage devices 550 . The operations of being both a primary and standby appliance are multitasked.
[0028] Standby appliance 530 monitors the status or the “health” of its primary appliance 525 through a communications link called the health monitor link 535 . Messages called “fail-over heartbeats” are sent from standby appliance 530 to primary appliance 525 , and if the messages are properly acknowledged the status of primary appliance 525 is acceptable. A “heartbeat” system is disclosed with more specificity in U.S. patent application Ser. No. 09/925,976, filed Aug. 9, 2001, entitled “System And Method For Computer Storage Security,” the disclosure of which has already been expressly incorporated herein by reference. If the heartbeat is not properly acknowledged or not acknowledged at all, then standby appliance 530 will begin the procedure for taking over the tasks of primary appliance 525 . The heartbeat can also be implemented such that the heartbeat is sent from primary appliance 525 to standby appliance 530 ; this simply is a choice based on the software's architecture and ease of implementation. If a standby appliance 530 is a fail-over appliance for multiple primaries, the communications link can be configured to be shared among all primary appliances 525 or one dedicated communications link can be connected from each primary appliance 525 to standby appliance 530 . The communications link can be any type of medium or protocol such as, for example, an Ethernet IP connection, a fibrechannel connection or a serial connection. It is also possible that the health monitor can also function from standby FC adapter 517 along standby path 520 to monitor the status of the primary appliance.
[0029] The health monitor link 535 performs several tasks:
[0030] 1. It is used to monitor the status of the primary appliance. The standby appliance sends a request for the primary appliance's status. This is the heartbeat. The primary appliance sends the status data to the standby appliance, and the data are then analyzed. If a problem is discovered, the standby appliance will instruct the primary appliance to shut down.
[0031] 2. Health monitor link 535 is used to initially transfer all the required information from the primary appliance to the standby appliance that is needed to emulate the primary appliance in the event that a fail-over event takes place when the standby appliance was assigned as the fail-over appliance for the primary appliance. This information includes the operating parameters and data for the primary appliance and is static. “Static” means that the parameters do not change during the operation of the primary appliance. If the parameters are changed due to new requirements and needs by the user, the primary appliance will transfer the new information to the standby appliance. An alternative implementation is that the standby appliance is notified of the change and a request is sent from the standby appliance to the primary appliance to retrieve the new set of parameters. Currently the first method is used (request from primary appliance to standby appliance) but future implementations due to evolution of the fail-over feature may require the latter method.
[0032] 3. Health monitor link 535 is used to transfer any information from the primary appliance to the standby appliance at the time of fail-over if the primary appliance continues to run. This information is used to help smooth the standby appliance's fail-over process. This information is dynamic and is not required by the standby appliance—the information is merely helpful. The information is dynamic because its content is based on its current operating state. The information is not required because if the primary appliance failure were due to a system crash, the standby appliance would not be able to receive this information.
[0033] 4. Health monitor link 535 is used by the primary appliance to inform the standby appliance to begin taking over if the primary appliance discovers a problem where it becomes necessary for the primary appliance itself to initiate the fail-over process.
[0034] 5. Health monitor link 535 is used by the standby appliance to inform the primary appliance to shut itself down so that the standby appliance can take over the primary appliance's tasks if it detects over its health monitor link an imminent failure of the primary appliance.
[0035] 6. Health monitor link 535 is used by the standby appliance to inform the primary appliance to resume its FC activities when the primary appliance's failure has been fixed. The standby appliance does this by maintaining its connection with the primary appliance even though the primary appliance is no longer active to receive or send commands and data. The primary appliance continues to send status data to the standby appliance. When the problem affecting the primary appliance has been repaired, the standby appliance will be informed via the status data, whereby the standby appliance will begin de-activating itself from receiving additional commands and data from the SAN client and will instruct the primary appliance to begin its start-up procedure to resume receiving commands and data from the SAN client once again.
[0036] Standby appliance 530 also takes over its primary appliance's tasks if health monitor link 535 is broken or the heartbeat is not acknowledged. Health monitor link 535 may be broken due to a cut cable or “accidental” removal. The heartbeat may not be acknowledged because primary appliance 525 loses power, crashes, or incurs another similar event. Although a broken link 535 does not affect the ability of primary appliance 525 to perform its tasks, primary appliance 525 will be regarded as a failed appliance nonetheless, and standby appliance 530 will take steps to begin to take over the tasks from primary appliance 525 . Since standby appliance cannot communicate to primary appliance 525 to shut itself down, a backup method is used to pass on the shutdown signal.
[0037] [0037]FIG. 4 illustrates a failed health monitor connection 600 and the method used to send a shutdown signal. Since primary appliance 605 and standby appliance 610 are connected to the same storage device 630 , storage device 630 will become the medium used to pass the shutdown signal to primary appliance 605 . A common file or a disk sector (or sectors) 625 is reserved on the storage device 630 . Primary appliance 605 monitors the common file or disk sector 625 at regular, pre-defined intervals for instructions from standby appliance 610 . If standby appliance 610 detects no acknowledgement from its heartbeats or there is a broken health monitor link, the standby appliance writes into common file 625 an instruction for primary appliance 605 to begin its shutdown procedures, which include completing outstanding tasks to its application/file servers and/or workstation and disconnecting itself from the fibrechannel communication network. If primary appliance 605 is alive, which means that the health monitor link is corrupted, the primary appliance reads the shutdown signal from the common file 625 and writes an acknowledgement into the common file 625 that it has received the shutdown signal and is beginning its shutdown procedure. Standby appliance 610 then waits a pre-determined amount of time for a message to come through the common file 625 from primary appliance 605 that the latter has completed its shutdown procedure. Standby appliance 610 monitors the common file 625 for the completion message during this time interval, and begins its start-up procedures as soon as the completion message is given. When the shutdown procedure is completed by primary appliance 605 , primary appliance then writes a shutdown completion message to common file 625 , and standby appliance 610 begins its procedure to become active and take over the tasks of its failed primary appliance 605 . If standby appliance 610 does not receive a shutdown completion message from primary appliance 605 within a pre-determined time interval, standby appliance 610 assumes that primary appliance 605 has become totally inoperative and initiates its procedures to become active to take over the tasks of the failed primary appliance 605 . Since common file 625 is used as a backup communication link between the appliances, it is also used to communicate any dynamic information from the primary appliance to the standby appliance that may be helpful to the fail-over process. This information can be historical and/or state information, which can be used during start-up procedures by either appliance. For example, if the primary appliance is turned off followed by the standby appliance being turned off, the standby appliance writes a message to the storage device indicating that it is no longer operating in place of the primary server. If the primary appliance resumes operation before the standby appliance, the primary appliance knows from reading the message that it is to resume processing commands and requests. As stated earlier, this information is not required for the fail-over process—it simply makes the process easier.
[0038] If primary appliance 605 initially becomes inoperative because of loss of power, system crash, or some other catastrophic event, standby appliance 610 writes its shutdown message to the common file 625 with the assumption that primary appliance 605 may still be active. Standby appliance 610 functions in this manner because it cannot be assumed that primary appliance 605 is totally inoperative. A predetermined time interval is given by standby appliance 610 for primary appliance 605 to respond to the shutdown message, and if the shutdown message is not acknowledged standby appliance 610 begins its procedures to become active to take over the tasks of the failed primary appliance 605 . Standby appliance 610 monitors the common file 625 for the shutdown acknowledgement message, and as soon as this message is received standby appliance 610 waits for the shutdown completion message.
[0039] [0039]FIG. 5 is a flowchart which describes the actions taken by primary appliance 605 and standby appliance 610 when the health monitor link or primary appliance is non-functional. Blocks 700 through 715 illustrate the steps undertaken by primary appliance 605 . At block 700 , primary appliance 605 receives the shutdown message in common file 625 from standby appliance 610 . Primary appliance 605 writes a shutdown acknowledgment message to common file 625 at block 705 . At block 710 , primary appliance 605 begins its shutdown procedure by completing outstanding tasks and disabling its connections. Finally, at block 715 , primary appliance 605 writes its shutdown completion message to common file 625 .
[0040] Blocks 720 through 760 detail the steps employed by standby appliance 610 . At block 720 , standby appliance 610 detects the lack of a response from the health monitor link. In step 725 , standby appliance 610 next writes the shutdown message to common file 625 . The program proceeds to blocks 730 and 740 to wait for a shutdown acknowledgment message from primary appliance 605 . Block 730 , which queries whether the shutdown acknowledgment message has been received from primary appliance 605 . If the answer is “NO,” the program proceeds to decision block 740 , which queries whether the predetermined time period has expired. If the answer at decision block 740 is “NO,” the program loops back to block 730 . If the answer at decision block 740 is “YES,” the program proceeds to block 760 where standby appliance 610 begins procedures to become active and to take over the tasks of primary appliance 605 . Returning to decision block 730 , if the answer to the query is “YES,” the program proceeds to blocks 750 and 755 where standby appliance 610 waits for the shutdown completion message from primary appliance 605 . In decision block 750 , the program queries whether the shutdown completion message has been received from primary appliance 605 . If the answer is “NO,” the program proceeds to decision block 755 , which queries whether the predetermined time period has expired. If the answer at decision block 755 is “NO,” the program loops back to block 750 . If the answer at decision block 755 is “YES,” the program proceeds to block 760 where standby appliance 610 begins procedures to become active and to take over the tasks of primary appliance 605 . Returning to decision block 750 , if the answer to the query is “YES,” the program again proceeds to decision block 760 , as discussed immediately above.
[0041] After the shutdown completion message is received or after the time has expired waiting for the shutdown acknowledgement or completion messages, the standby appliance begins its procedures to become active. From FIG. 3, standby appliance 530 reprograms its standby FC adapter 517 with the WWPN address from primary FC adapter 516 . Standby FC adapter 517 was given a temporary WWPN address in order for it to be connected to the fibrechannel fabric. Standby appliance 530 knows the WWPN address of the primary appliance because when standby appliance 530 was initially assigned to be the fail-over appliance for primary appliance 525 , it communicated with primary appliance 525 to transfer all the necessary information it needed to perform the emulation. This information included the WWPN address of primary FC adapter 516 .
[0042] A flowchart in FIG. 6 shows the steps taken by standby appliance 530 . At block 800 , standby appliance 610 initiates its activation procedures. Standby appliance 610 checks its connection at block 805 to ensure functionality. At block 810 , standby appliance 610 retrieves the saved WWPN address of the FC adapter of failed primary appliance 605 . Standby appliance 610 reprograms its standby FC adapter with the new WWPN address at block 815 . Finally, at block 820 standby appliance 610 is functionally able to manage storage for the SAN client of failed primary appliance 605 , in a manner transparent to the SAN client.
[0043] Once the WWPN address is programmed into standby FC adapter 517 , SAN client 500 will not be aware of the change in appliances. Standby appliance 530 will now receive all the data traffic that was bound for failed primary appliance 525 . When a standby appliance is a fail-over appliance for one or more than one primary appliances, a table is kept to store and keep track of the information needed to emulate the primary appliances, which includes the WWPN addresses.
[0044] The technology of the present invention is not limited to one standby appliance that can act as a fail-over to a set of primary appliances. As illustrated in FIG. 7, the present invention also encompasses having a standby fail-over appliance 910 acting as a fail-over appliance to another standby fail-over appliance 920 . In this way, such multiple backup systems protect businesses' computer and storage systems from failing.
[0045] It should be understood by those skilled in the art that the present description is provided only by way of illustrative example and should in no manner be construed to limit the invention as described herein. Numerous modifications and alternate embodiments of the invention will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the following claims.
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In a system for appliance back-up, a primary appliance is coupled to a network, whereby the primary appliance receives requests or commands and sends a status message over the network to a standby appliance, which indicates that the primary appliance is operational. If the standby appliance does not receive the status message or the status message is invalid, the standby appliance writes a shutdown message to a storage device. The primary appliance then reads the shutdown message stored in the storage device and disables itself from processing requests or commands. When the primary appliance completes these tasks, it disables communication connections and writes a shutdown completion message to the storage device. The standby appliance reads the shutdown completion message from the storage device and initiates a start-up procedure. This procedure causes the address of the standby appliance to be identical to the primary appliance address, and the standby appliance processes the requests or commands in place of the primary appliance.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national stage application of International Application No. PCT/EP2009/064020, filed on Oct. 23, 2009, which claims the benefit of German Patent Application No. DE 10 2008 053 145.6, filed on Oct. 24, 2008, the entire contents of both applications are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention relate to a flow directing device for a cooking appliance with a fan mechanism, which comprises at least one fan wheel in an interior of the cooking appliance for circulating atmosphere, comprising at least one first flow directing member for subdividing the interior into a pressure chamber with the fan wheel and a cooking chamber, wherein the first flow directing member leaves free at least one suction port for sucking atmosphere from the cooking chamber into the pressure chamber in the area of the fan wheel and at least one blow-off port for blowing atmosphere from the pressure chamber into the cooking chamber when the fan wheel is in operation, at least one second flow directing member, which is mounted onto the fan mechanism or molded with the fan mechanism in the area of the suction port of the first flow directing member in order to improve the flow from the cooking chamber into the pressure chamber by forcing an axial main flow in the suction zone of the fan mechanism, and a cooking appliance with such a flow directing device.
[0004] 2. Description of the Related Art
[0005] In the prior art, numerous measures for optimising a flow in the interior of a cooking appliance are known. Usually, a first flow directing member is used in the form of an air directing plate between a cooking chamber and a fan chamber or pressure chamber, which comprises a central suction port and leaves open blow-off ports facing the walls of the interior, so that a fan wheel arranged in the pressure chamber can suck atmosphere from the cooking chamber through the suction port and blow it out via the blow-off ports.
[0006] DE 203 14 818 U1, for example, deals with the targeted blowing of atmosphere from the pressure chamber into the cooking chamber via specially arranged blow-off ports in the first flow directing member. DE 10 2007 023 767, which is not pre-published, also deals with the blow-off ports of a first flow directing member, wherein movable elements should be arranged in blow-off ports, which move depending on the pressure progression in the cooking chamber. Another approach can be found, for example, in DE 203 09 268 U1 by using second flow directing members in the fan chamber in which a breaking up of the eddies should be forced while passing through a blow-off port between the pressure chamber and the cooking chamber, so that eddies spread out in the cooking chamber. Second flow directing members for forcing a homogeneous flow in the cooking chamber are also described in DE 203 12 031 U1.
[0007] A further flow directing device can be found, for example, in DE 10 2004 004 393 B4, in which a first flow directing member is in the form of a single piece with a second flow directing member. More precisely, the edge of the first flow directing member is turned in the form of an air directing plate in the area of its suction port to form a flow directing nozzle. This nozzle is a suction nozzle and is designed to improve the suction of atmosphere from a cooking chamber into a fan chamber of a cooking appliance. However, the disadvantage here is that a gap must be present at all times between a rotating fan wheel in the pressure chamber on the one hand, and the suction nozzle on the air directing plate on the other, in order to avoid damage. With cooking appliances in industrial kitchens in particular, this gap is large enough, due to tolerances, to enable atmosphere to flow from the pressure chamber directly into the suction area of the fan wheel, i.e., it is not directed via a blow-off port into the cooking chamber and via the suction port of the air directing plate into the suction area of the fan wheel, so that a short-circuit occurs with the atmosphere, which flows in from the cooking chamber through the suction port of the air directing plate. For this reason, this flow, which penetrates through the gap, is also known as a short-circuit flow, and occurs at a very sensitive point in the suction area of the fan wheel, i.e., in the deflection area of a main flow from the cooking chamber into the pressure chamber, more precisely, where a deflection occurs from a radial direction into an axial direction of the main flow. Thus, the short-circuit flow runs transverse to the main flow in the suction area of the fan wheel, so that it narrows the main flow and can itself cause a displacement and swirling of the main flow, which leads to an overall reduction in the effectiveness of the circulation of cooking chamber atmosphere by the fan wheel.
[0008] Generic flow directing devices for cooking appliances are described in EP 1 767 869 A2 and DT 25 19 604, wherein in both cases, a first flow directing member spreads out at least up to the suction port of a fan wheel, and in the case of DT 25 19 604, even extends into the suction port, while the second flow directing member is provided in the form of an outer contour of the fan wheel.
SUMMARY OF THE INVENTION
[0009] The object of the embodiments of the present invention is therefore to further develop the generic flow directing device in such a manner that it overcomes the disadvantages of the prior art. In particular, the effectiveness of a circulation within the interior of a cooking appliance should be improved.
[0010] This object is attained according to the embodiments of the present invention by means of the fact that each second flow directing member fulfils or performs a nozzle function, extends from the fan mechanism into the cooking chamber, and protrudes over or overlaps the edge of the suction port of the first flow directing member, while the first flow directing member spreads out into each second flow directing member.
[0011] Here, it is preferred that in cases when the fan mechanism comprises at least one radial fan, which includes a plurality of blades that are attached to a holding device, in particular, in the form of a support ring, and are arranged concentrically with a drive shaft, the second flow directing member is attached or molded with the shaft, the holding device, in particular, the support ring, and/or at least one blade.
[0012] According to embodiments of the present invention, it can here in turn be provided that the second flow directing member is in the form of a ring, in particular when attaching it to the holding device or molding it to the holding device.
[0013] Embodiments of the present invention are also directed to second flow directing members that extend into the pressure chamber up to the pressure area of the fan wheel.
[0014] Furthermore, it can be provided that each second flow directing member comprises a profile form of such a type that a flow from the cooking chamber into the pressure chamber only separates from the axial main flow as far as possible inside the pressure chamber, wherein preferably, an essentially hook-shaped profile or, in particular an asymmetric, U-shaped profile with an extended free end of the second flow directing member, is molded in the pressure chamber.
[0015] Additionally, embodiments of the present invention are directed to first flow directing members that are attached or are attachable to a wall of the interior.
[0016] Further embodiments of the present invention can also include by a third flow directing member in the pressure chamber, which, in particular, limits a blow-off area of the radial fan that extends conically outwards from the fan wheel of the radial fan.
[0017] Additionally, the third flow directing member can be attached to the first flow directing member, or can be moulded together with it.
[0018] Alternatively, the third flow directing member can be an extension of the second flow directing member, in particular at the free end of the second flow directing member in the pressure chamber.
[0019] According to the embodiments of the present invention, it is also recommended that the first flow directing member, the second flow directing member and/or the third flow directing member is or are in each case molded from at least one punched bending part and/or plate and/or is or are detachably affixed and/or is or are at least partially movable, or movable in sections.
[0020] Furthermore, the end of the second flow directing device can extend into the pressure chamber into a recess in the first and/or third flow directing device.
[0021] Particularly advantageous embodiments of the present invention are characterized by a plurality of fourth flow directing members, in particular, one fourth flow directing member for each blade, wherein, preferably, each fourth flow directing member is designed as a blade and/or as a blade extension, and most preferably extending through the support ring.
[0022] The embodiments of the present invention also provide a cooking appliance with a heating mechanism for heating atmosphere in a cooking chamber, a fan mechanism for circulating atmosphere at least in the cooking chamber and a flow directing device according to the embodiments of the present invention.
[0023] Additionally, the first flow directing member, the second flow directing member and/or the third flow directing member can be movable at least partially or in sections, preferably via a control or regulating mechanism, which interacts with the heating mechanism, the fan mechanism, a steam feed mechanism, a steam removal mechanism, a cooling mechanism, an energy saving mechanism, a microwave source, a gas feed mechanism, a gas removal mechanism, a sensing mechanism and/or a cleaning mechanism.
[0024] Finally, a shield, which can be of a grid or screen type, at least of the second flow directing member in the cooking chamber, can be affixed or is affixable in particular, to the first flow directing member, preferably in a detachable manner.
[0025] The embodiments of the present invention are thus based on the surprising finding that on the one hand, at least one first stationary flow directing member, for example, in the form of a standard air directing plate, is used in the interior of a cooking appliance, in order to separate the interior into a pressure chamber and a cooking chamber, wherein the first flow directing member leaves free a central suction port and at least one blow-off port on the edge side, and is affixed to the wall of the interior, while on the other hand, at least one second flow directing member is used, which fulfils or performs the function of a nozzle and which extends from a fan wheel in the pressure chamber, to which it is attached or molded together, through the suction port of the first flow directing member, so that the second flow directing member turns with the fan wheel. In a particularly advantageous manner, the nozzle, in particular, in the form of a ring is attached to a support ring for the blades of a radial fan, or is formed from a plurality of blade extensions. In any case, due to the nozzle, which rotates with the fan wheel, a radial flow is avoided in the suction area of the fan wheel, and thus, a short-circuit flow is also prevented. This increases the efficiency of the fan wheel and reduces the sensitivity of the entire cooking appliance to size tolerances.
[0026] Because radial fans are in principle relatively compact and are highly efficient, they are preferably used with a flow directing device according to the embodiments of the present invention. The high pressure area (the pressure side of the fan) and the suction area (the suction side of the fan) of a radial fan are relatively close to each other, so that due to the nozzle on the radial fan, a significant increase in fan capacity or reduction in the consumption capacity of the fan motor, is provided.
[0027] When the nozzle and the blades of the radial fan are affixed to a shared shaft, a separate fan housing is no longer required. The air directing plate and the nozzle, together with a wall of the interior, which is arranged opposite the air directing plate, form a type of fan housing. However, it is preferred that a shield is provided over the suction area of the radial fan in the cooking chamber in order to avoid injury, and is preferably attached to the first flow directing member.
[0028] Due to the size and geometry of the nozzle, further advantages can be attained, namely for the targeted directing of the flow. If the nozzle extends, on the one hand, in the pressure chamber into the area in which the blades of the radial fan create a pressure increase, the quantity of short-circuit flow is further reduced. If, on the other hand, the nozzle extends into the cooking chamber, an eddy formation in the suction area of the radial fan is reduced.
[0029] It is preferred according to the embodiments of the present invention that a third flow directing member is also used, which ensures that in the blow-off area of the radial fan, the pressure chamber comprises a chamber that extends radially outwards, so that the third flow directing member acts as a diffuser and further reduces the occurrence of short-circuit flows. The third flow directing member can be realised together with the first flow directing member.
[0030] Further features and advantages of the embodiments of the present invention are explained in the description of exemplary embodiments below with reference to the accompanying figures described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 shows a partial profile view of a cooking appliance according to an embodiment of the present invention;
[0032] FIG. 2 shows an enlarged view of detail AA in FIG. 1 ; and
[0033] FIG. 3 shows a perspective view of an alternative fan wheel for a cooking appliance according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0034] A cooking appliance according to the embodiments of the present invention comprises, as is shown in FIG. 1 , an interior 1 , which houses a fan wheel 2 in the form of a radial fan wheel. The fan wheel 2 is mounted on a drive shaft 3 of a motor (not shown), which is located outside the interior 1 . If, as an alternative, the motor were to be located inside the interior 1 , then cooling measures would be required.
[0035] Although in principle, an axial fan could also be used, a radial fan has the advantage that atmosphere, which is brought into rotation, in particular cooking chamber atmosphere, does not impact against a rear wall 4 of the interior 1 , but is instead deflected into the fan wheel 2 . As a result, the arrangement is compact and has a high degree of efficiency.
[0036] The fan wheel 2 sucks in atmosphere centrally, namely, from a suction area 5 , (see the suction flow E in FIG. 1 ), and blows it off radially, namely, into a blow-off area 6 , (see the blow-off flow A in FIG. 1 ). In principle, a variant would also be feasible in which the atmosphere flows in the reverse direction, wherein measures would then have to be provided in order to avoid a transverse flow in the blow-off area 6 .
[0037] The interior 1 is divided by a first flow directing member, for example, in the form of an air directing plate 7 , at least partially into a cooking chamber 8 and a pressure chamber 9 . The air directing plate 7 is, for example, affixed in a detachable and lockable manner via bridges or bars (not shown) to the walls of the interior 1 . The fan wheel 2 is mounted separately in the cooking appliance, namely, with the fan wheel 2 in the pressure chamber 9 , without a fixed connection to the air directing plate 7 . The air directing plate 7 leaves gaps 10 a on its outer edges open for the blow-off flow A and comprises a central opening 10 b for the suction flow E, which is regulated in accordance with the suction area 5 .
[0038] Due to the circulation of the atmosphere in the interior 1 , evened heating of the item of food to be cooked (not shown) in the cooking chamber 8 is possible after the atmosphere has been heated using a heating means (not shown), both in conventional ovens and baking and roasting ovens, which also have a steam function and/or microwave charge, for example. The heating means can be designed in the form of heating coils around the fan wheel 2 , for example.
[0039] In order to improve the deflection of atmosphere from the suction area 5 into the fan wheel 2 , and to avoid transverse and counterflows, which could lead to short-circuit flows that could negatively impact the capacity of the fan, a nozzle 11 is provided as a second flow directing member in the area of the opening 10 b of the air directing member 7 on the fan wheel 2 . The nozzle 11 primarily directs atmosphere in the axial direction into the fan wheel 2 . As is shown in FIG. 1 , atmosphere is predominantly sucked in in the radial edge area of the suction area 5 of the fan wheel 2 in the form of a main flow H, for which reason the nozzle 11 is not only matched in terms of its arrangement and size to the suction area 5 , but also to the opening 10 b of the air directing plate 7 .
[0040] The fan wheel 2 comprises blades 12 . The end of each blade 12 , which, from the perspective of the axial direction, is located on the suction side of the fan wheel 2 , is here restricted by a ring-shaped wall 13 of a support ring, which is part of the fan wheel 2 and which is thus affixed on the shaft 3 in such a manner that it rotates. The nozzle 11 as depicted in the exemplary embodiment shown in FIG. 1 , is firmly attached to this support ring or to this ring-shaped wall 13 and is itself in the form of a ring, so that a continuous sealing off of the pressure chamber 9 against the main flow H is provided. As a result, transverse and counterflows are to a large extent avoided in the area of the main flow H.
[0041] In an alternative embodiment, the nozzle can be affixed in another manner to the fan wheel for the purpose of avoiding the aforementioned transverse and counterflows. In principle, it would be possible, for example, to mount the nozzle onto an extension of the shaft in such a manner that it either rotates or does not rotate, which, however would require a precise maintenance of tolerance limits in terms of the distance between the fan wheel and the nozzle, which should be kept as small as possible. This, however, would not be advantageous. By contrast, it is advantageous to mold the nozzle in the form of additional blades that extend from the wall 13 in the direction of the air directing plate 7 , or that extend as extensions of the blades 12 , which extend through the wall 13 in the direction of the air directing plate 7 . This embodiment enlarges the suction area 5 of the fan wheel 2 while maintaining the same installation space. Furthermore, the conveyance capacity of the fan wheel 2 is also enlarged, so that the cooking speed is increased or the capacity of the fan drive can be reduced. At the same time, the ejection behaviour of the fan wheel 2 is improved due to the fact that the profile through which the flow moves is enlarged when the fan wheel 2 is left. Due to the larger profile through which the flow moves, circulation around the heating means is also more effective, which leads to an improved heating of the item of food to be cooked.
[0042] Whether the nozzle 11 is in the form of a ring or in the form of a plurality of blade extensions on the support ring wall 13 , has no influence over the fact that the opening 10 b of the air directing plate 7 can be relatively freely selected, and the cooking appliance is no longer dependent to a high degree on tolerances with regard to the flow directing members 7 , 11 .
[0043] With regard to FIG. 2 , the progression of the various flows between the pressure chamber 9 and the cooking chamber 8 will now be described in detail.
[0044] In the area between the fan wheel 2 , which rotates when in operation, and the air directing plate 7 , there is a gap 14 . The gap 14 here is of such a size that it is guaranteed that the rotating fan wheel 2 together with the nozzle 11 under no circumstances brushes against the air directing plate 7 , which does not rotate. The dimensions of the gap 14 are in a way dependent on the production tolerances of both the air directing plate 7 or its opening 10 b, of the fan wheel 2 or its blades 12 , of the wall 13 , and of the nozzle 11 . The gap 14 opens a connection between areas with large pressure differences that leads to a counterflow G, which separates from the blow-off flow A, and which flows from the pressure chamber 9 into the cooking chamber 8 , more precisely from the blow-off area 6 of the fan wheel 2 into its suction area 5 . In order for this counterflow G to run first radially in the pressure chamber 9 in the direction of the rotation axis of the fan wheel 2 , then essentially axially in the area of the air directing plate 7 , and finally radially outwards in the cooking chamber 8 in order to avoid to the greatest extent possible an interaction with the main flow H, i.e. to form no short-circuit flow, the nozzle 11 extends from the perspective of the axial direction until at least up to the opening 10 b in the air directing plate 7 . In order to prevent the counterflow G from immediately flowing back into the suction area 5 , the nozzle 11 itself protrudes through the opening 10 b into the cooking chamber 8 . Furthermore, the counterflow G is deflected away in the radial direction from the suction flow E by the nozzle 11 widening out towards the suction area 5 . The radius of the edge 15 of the nozzle 11 , which faces away from the cooking chamber 8 , is by contrast larger than the radius of the opening 10 b in the air directing plate 7 . As a result, the flow resistance of the gap 14 is increased, on the one hand, and on the other hand the strength of an eddy formation and the volume of the counterflow G, is are reduced.
[0045] In order to prevent the rotating nozzle 11 from touching objects located in the cooking chamber 8 , such as an oven rack or similar structures, an air permeable shield 16 is provided. This shield 16 , which can be, for example, in the form of a grid or screen, is attached to the air directing plate 7 and also serves to protect against injury by preventing access to the fan wheel 2 .
[0046] An eddy formation can be further reduced in one embodiment according to embodiments of the present invention by the use of a third flow directing member in the form of an additional air directing plate 17 which functions as a diffuser. The additional air directing plate 17 can be mounted onto the first air directing plate 7 or be molded with the first air directing plate 7 . In any case, a distance B 1 between the additional air directing plate 17 and the rear wall 4 of the pressure chamber 9 is increased radially outwards relative to the longitudinal axis of the shaft 3 (rotation axis of the fan wheel), at least in the blow-off area 6 . The blow-off flow A, which flows out of the fan wheel 2 thus reaches the blow-off area 6 without significant changes to its profile, and flows onwards to the gaps 10 a between the first air directing plate 7 and the interior wall, wherein due to the flow directing mechanisms, eddy formations are avoided and short-circuit flows are reduced.
[0047] The invention is not restricted to the embodiments described in detail herein, but can be varied within the scope of protection of the appended claims. For example, the edge 15 of the nozzle 11 can protrude into a recess formed by a branching of the first and/or second air directing plate 7 , 9 for the purpose of further increasing the resistance experienced by the counterflow G.
[0048] An alternative fan wheel, or radial fan wheel 210 is shown in FIG. 3 and comprises a disc-shaped bearing disc 212 , several main blades 214 , which are affixed on the bearing disc 212 with the same degree of separation, and a support or bearing ring 218 , which is equipped with directing blades 216 and which is affixed at a distance to the bearing disc 212 on the main blades 214 .
[0049] The bearing disc 212 is provided with a central recess 220 , wherein a central axis of the recess 220 corresponds with a central axis 222 of the bearing disc 212 . In an area located radially in the interior, the bearing disc 212 , which is produced from a plate board, is provided with a hub designed to guarantee a reliable attachment to a drive device (not shown) and a stable radial runout of the radial wheel 210 , even under high rotational speeds. The main blades 214 are with the present embodiment arranged in such a manner that they incline backwards on the bearing disc 212 . In other words, a rotational speed vector 224 , which is applied tangentially on the outer circumference of the bearing disc 212 , incorporates an acute angle with a largest surface 226 of the main blade 214 , as is shown symbolically in FIG. 3 .
[0050] With the embodiment of the radial wheel 210 shown in FIG. 3 , the directing blades 216 are designed as a single piece with the main blades 214 so that largest surfaces of the directing blades 216 incorporate the same acute angle with the rotational speed vector 224 as the largest surfaces 226 of the main blades 214 . The main blades 214 are in each case angled at right-angles on an end area, which is set opposite the directing blades 216 , so that they can be affixed by adhesive bonding, for example, by glueing or spot-welding, to the bearing disc 212 which is preferably made of metal.
[0051] The directing blades 216 protrude orthogonally from the surface of the bearing disc 212 .
[0052] The bearing ring 218 is provided with slits, not shown in greater detail, which are punctuated by the directing blades 216 , which are connected as a single piece with the main blades 214 . The directing blades 216 are affixed using a adhesively bonded connection, in particular a weld or solder connection, to the bearing ring 218 , and protrude orthogonally from said ring. Radially external front sides of the main blades 214 and of the directing blades 216 are with the present embodiment of the radial wheel, aligned orthogonally to a largest surface 230 of the bearing disc 212 . Radially internal front sides 232 of the main blades 214 are curved, and thus only essentially aligned orthogonally to the largest surface 230 of the bearing disc 212 .
[0053] As depicted in FIG. 3 , the bearing ring 218 of the present embodiment, is designed as a single piece, made of a planar ring 234 and a suction mouth 236 , which connects radially internally, and is formed as a cone sheath section profile, and which provides a nozzle and thus also acts as a second flow directing member. The directing blades 216 are sized in such a manner that they extend from the radially external edge 238 of the planar ring 234 through to the radially internal edge 240 of the planar ring 234 . The inner edge 242 of the suction mouth 236 limits the suction profile of the radial wheel 210 .
[0054] Cooking chamber atmosphere that is sucked in by the radial wheel 210 and which flows through the suction port of a first flow directing member according to FIGS. 1 and 2 , is either directed through the suction mouth 236 , i.e., the second flow directing member, and accelerated outwards by the main blades 214 in the radial direction, or enters a gap, which remains between the suction mouth 236 and the first flow directing member. In the gap, the directing blades 216 ensure that unwanted turbulences, which could reduce the effectiveness of a fan arrangement that is equipped with the radial wheel 210 , are avoided. The directing blades 216 thus act as further flow directing members (fourth flow directing members) in order to increase the efficiency of the radial wheel 210 .
[0055] The features of the embodiments of the present invention explained in the above description, in the drawings and in the claims, can be integral both individually as well as in any combination required in order to realise the invention in its different embodiments.
LIST OF REFERENCE NUMERALS
[0056] 1 Interior
[0057] 2 Fan wheel
[0058] 3 Shaft
[0059] 4 Rear wall
[0060] 5 Suction area
[0061] 6 Blow-off area
[0062] 7 Air directing plate
[0063] 8 Cooking chamber
[0064] 9 Pressure chamber
[0065] 10 a Gap
[0066] 10 b Opening
[0067] 11 Nozzle
[0068] 12 Blade
[0069] 13 Support ring wall
[0070] 14 Gap
[0071] 15 Edge
[0072] 16 Shield
[0073] 17 Air directing plate
[0074] 210 Radial wheel
[0075] 212 Bearing disc
[0076] 214 Main blade
[0077] 216 Directing blade
[0078] 218 Bearing ring
[0079] 220 Recess
[0080] 222 Central axis
[0081] 224 Rotational speed vector
[0082] 226 Surface
[0083] 230 Surface
[0084] 232 Front side
[0085] 234 Planar ring
[0086] 236 Suction mouth/nozzle
[0087] 238 Radially external edge
[0088] 240 Radially internal edge
[0089] 242 Inner edge
[0090] H Main flow
[0091] G Counterflow
[0092] E Suction flow
[0093] A Blow-off flow
[0094] B 1 Distance
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A cooking appliance including an interior, a fan mechanism having at least one fan wheel in the interior, at least one first flow directing member for subdividing the interior into a pressure chamber that houses the fan wheel and a cooking chamber, in which the first flow directing member includes at least one suction port for sucking atmosphere from the cooking chamber into the pressure chamber when the fan wheel is in operation and at least one blow-off port for blowing atmosphere from the pressure chamber into the cooking chamber when the fan wheel is in operation; and at least one second flow directing member that is included with the fan mechanism in the area of the suction port of the first flow directing member in order to improve the flow from the cooking chamber into the pressure chamber by forcing an axial main flow H in the suction zone of the fan mechanism, where the second flow directing member performs a nozzle function, extends from the fan mechanism into the cooking chamber, and overlaps the edge of the suction port of the first flow directing member, and where the first flow directing member extends into the second flow directing member.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to pocket wheel furnaces for maintaining the orientation of small components being treated in the pockets of a rotary furnace preparatory to plug quenching.
2. Description of the Prior Art
Existing furnaces used for plug quenching all experience difficulty in discharging or extracting small size product components preparatory to delivery of such product or component to a quench press. Whether the existing furnaces are operated by belt, or rotary tray or by rail, the orientation must be proper to obtain effective and acceptable plug quenching.
Examples of the prior art furnaces are seen in U.S. Pat. No. 3,727,896 of Apr. 17, 1973, or U.S. Pat. No. 4,622,006 of Nov. 11, 1986, or U.S. Pat. No. 4,738,577 of Apr. 19, 1988 wherein no particular attention is given to the position of a product in the furnace so its emergence may be substantially correct or best for the quench treat that may follow.
Mechanisms useful in association with rotary furnaces for heat treatment of products are seen in U.S. Pat. No. 4,622,006 of Nov. 11, 1986, or U.S. Pat. No. 4,763,880 of Apr. 17, 1988.
The foregoing prior art examples do not express concern for handling of workpieces in regard to the expected need for quenching following furnace treatment, nor do such examples make any provisions for treating small parts so that they are properly positioned for quenching.
BRIEF SUMMARY OF THE INVENTION
An important object of the invention is to obtain the discharge of products from a furnace while concurrently maintaining orientation of the product through the simple rotation of a wheel with no additional moving parts within the furnace.
Another object of the invention is obtained by the automatic handling of small size product through a heating and/or hardening furnace while maintaining the orientation of such part for subsequent quenching.
Yet another object of the present invention is to provide a charging and discharging mechanism for a rotary furnace in a vertical position so that the objects to be heat treated are properly positioned and remain in the furnace for a required dwell time and are discharged in a predetermined position for subsequent plug quenching.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is shown in the following drawings, wherein
FIGS. 1 and 2 are respectively a cross-section of a heat treating furnace, and a transverse sectional detail taken along the line 2--2 in FIG. 1 to illustrate the arrangement of zone heating elements in one side wall;
FIG. 3 is a schematic and fragmentary side view of a rotary pocket wheel in a furnace for heat treating components placed in the pockets as the wheel is indexed past a loading station, taken along line 3--3 in FIG. 1;
FIG. 4 is a fragmentary plan view of the loading mechanism for a single line of components in a single pocket wheel taken along line 4--4 in FIG. 3;
FIG. 5 is a schematic and fragmentary view of means for effecting discharge of components which have attained the desired temperature, the view being a continuation of FIG. 3 to show the discharge of components;
FIG. 6 is a fragmentary plan view of the transfer ram for moving heat treated components to a quench press, the viewing taken along line 6--6 in FIG. 5;
FIG. 7 is a fragmentary view taken along line 7--7 in FIG. 5 illustrating the pocket unloading means for at least two sizes of components;
FIG. 8 is a perspective view of a typical pocket for the wheel seen in FIG. 4;
FIG. 9 is a schematic diagram of a control system for the apparatus for heat treating components;
FIG. 10 is a schematic diagram of the zone temperature control system employed in the heat treating furnace of this invention;
FIG. 11 is a schematic diagram of a furnace atmosphere control system useful herein; and
FIG. 12 is a schematic perspective view of the system for rotating a double row pocket which is a heat treating furnace with means to load and discharge components at least two at a time.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The embodiment of a pocket wheel for a heat treating furnace is seen in FIG. 1 where the furnace F is indicated to have a metallic shell 10 of cylindrical form in section, with an inner insulation layer 11 lying next to the inner surface of the shell 10, and a wall of fire brick blocks 12 located around the interior of the insulation layer 11. The cylindrical shell 10 has opposite closure walls 13 and 14 to retain fire brick blocks in position to enclose the heat treating chamber 15. One end wall 13 is formed with an opening 16 to receive a rotary shaft 17 which supports a wheel 18 within the chamber 15. The periphery of the wheel 18 carries a circumferentially mounted array of pockets 19 which carry the components (not shown) to be heat treated. The source of the heat is an array of ribbon-type electrical heating elements arranged in three zones 20A, 20B and 20C, each suitably supported in the opposite end wall brick work 12 on opposite sides of the circular path of travel of the pockets 19.
Each pocket 19 (see FIGS. 7 and 8) is constructed of heat resistant metal and is formed with opposite side walls 21 spaced apart by transverse walls 22 for the reception of one or more components C at the loading zone when presented in a normal horizontal loading position at 180° reversed from the position seen in FIG. 8 where the under flat surface of the transverse walls 22 are uppermost. What is seen in FIGS. 7 and 8 is the bottom surface of walls 22 which are formed with raised triangle surfaces or projections 23 which have inner margins that are angled toward the center slots 24 opening through the walls 22 of the pocket for the purpose of centering the component C to be carried in the pockets when resting on a pair of such margins. Each wall as seen in FIG. 7 is formed with a slot 24 oriented to be on the radial center line of the wheel periphery so a stationary finger 41 is able to be located in line with radial center line of the wheel periphery for the purpose of allowing the pocket slots 24 passing the finger 41 which is adapted to lift whichever size of the component C is in the pocket over the projections 23 so the component can slide out of the pocket by gravity. In order to load and unload each pocket so the component is oriented in the desired position for plug quenching, the component C is inserted into the pocket when the flat surface of wall 22 is presented facing up in a horizontal position. The component has a front face that is presented to the flat surface of wall 22. The wheel rotates the component through about 260° from that horizontal position so the component is turned over to rest against the projections 23 with the opposite face down. In this instance the component C is a cup or a cone for a tapered roller bearing. If the component is a cup or a cone then the loading thereof into the pockets must be effected with its front face down so when turned over its back face will be down. Furthermore, each pocket 19 has aligned slots 19A that allow for a light beam to be directed through the pocket 19 to indicate when a pocket is positioned to receive a component.
Turning to FIGS. 3 and 4, the wheel 18 is assumed to have been indexed so each pocket 19 is presented with its flat surface aligned at the level with the slide 26, the slide being on a suitable support 27. The slide 26 extends through a guide chute device 28 which is equipped with a gate 29 operated by means of a power cylinder 30 to raise the gate (as seen in FIG. 3) so its window 31 opens the chute to allow a component to be propelled through the chute device 28 and into the waiting pocket 19. The propelling means 32 has its actuating piston 33 movable through support guide means 34 so its pusher can engage a component when placed on the slide 26. A suitable sensor 35 detects the presence of a component and energizes the piston 33 to propel the component into the pocket 19 and to retract the pusher 32. Thereafter the gate 29 closes the chute until a second pocket on wheel 18 is indexed to its loading position and a component C is detected in loading position on slide 26.
Turning to FIGS. 1 and 9, the drive system for operating the furnace pocket wheel includes a servo motor and resolver assembly indicated at 36 in FIG. 1 and set forth in greater detail in FIG. 9 at 36A and 36B. The combined assembly 36 is operatively related to the shaft 17 which rotates the wheel 18 in the furnace chamber 15. The control system seen in FIG. 9 shows the assembly 36 made up of an individual servo motor 36A and the resolver unit 36B, with the latter unit responsively connected to a programmable logic controller (PLC) 37.
A slot 36C (See FIG. 3) is cut in the inner rib of the wheel, and an infrared sensor 38 is aligned with that slot, and the home position is stored in the memory of the PLC 37 as a "Zero Degrees". The wheel 18 is then rotated until a pocket 19 aligns with the load position of the pusher 32 (see FIG. 3) and an infrared sensor 39 is located to give the resolver 36B the feedback degree position of the pocket to the PLC 37 where it is stored in the memory. The wheel 18 is continued to be rotated until all of the home positions of the pockets 19 have been stored in the PLC memory. Once the wheel 18 has been calibrated to stop at each load position detected by the infrared sensor 39, the PLC 37 is able to actuate the gate power cylinder 30 to open the gate 29 and to actuate the pusher 32 and its cylinder 33, provided the sensor 35 has detected the presence of a component on the slide 26. It is therefor understood that once the wheel 18 has been calibrated to rotate to a position for a pocket 19 the wheel stops, the furnace gate 29 opens and the pusher 32 loads the component on the slide 26 into the pocket. The wheel is then indexed by the PLC 37 to the next pocket. The speed at which the wheel moves between pockets depends on the desired heat treat for the component loaded into a pocket. Thus the dwell time is introduced to the PLC.
The indexing of the wheel 18 to bring each pocket into loading position opposite the guiding chute 28 continues as long as the supply of components is present. The residence or dwell time of each component in the heating chamber 15 (FIG. 1) is controlled by the rotating speed of wheel 18 and the level of the temperature in the furnace chamber 15. For hardening purposes the temperature in chamber needs to be at about 1600° F. for imparting that level of heat in each component by the time the wheel 18 is indexed around about 260° where the components begin to be discharged.
The discharge of components, upon completing the dwell time in the furnace F, are rotated to the position about 260°, more or less, where the pockets 19 have been rotated into the position (see FIGS. 7 and 8) where the walls 22 are presented with the retainer elements 23 uppermost, and the components are resting against the slanted surfaces of those elements and centered to a slot 24. As the wheel approaches the descending position of 260° from the loading position, there is a stationary finger 41 which is aligned with the slot 24 to lift the component above the elements 23 so they are able to discharge by gravity onto a chute 42 (see FIGS. 5 and 7) which directs the component into a position at the bottom 43 of the chute 42. The momentum of the component will project it onto the receiving surface 44 of the belt conveyor assembly 45. A motor 46 drives the power pulley 47 for the conveyor belt 44. A suitable sensor 45A detects the component and energizes a transfer mechanism 48 which includes a cylinder 49 (FIG. 6) with a pusher arm 50 which picks up a component from the top of the belt 44 and slides it on the surface 51 into a quench press 52. Since the wheel 18 is rotating in an indexed sequence, the components will be discharged only when a pocket 19 is moved past the stationary finger 41. It is contemplated that the components will be discharged in timed sequence that will not clog up the discharge assembly 45 and the transfer mechanism in response to the sensor 45A.
Since the function of the furnace F is to obtain a derived heat treatment of components C which may be bearing components, it is important to provide both a temperature control system and an atmosphere control system. These systems are depicted in a schematic way in FIGS. 10 and 11.
FIG. 10 illustrates temperature responsive thermocouples 53, 54 and 55 associated respectively with heat zones 20A, 20B and 20C. The thermocouples feed back to their respective temperature controllers 53A, 54A and 55A. If there is a deviation from the desired temperature, these controllers adjust the amount of power going to the ribbons heating means in zones 20A, 20B or 20C by sending a signal to the silicon controlled rectifiers (SCR) 53B, 54B and 55B which act as switches for the power going through the transformers 53C, 54C and 55C which respectively adjusts the power at the heating elements in zones 20A, 20B and 20C. It is understood that the thermocouples may not all respond in unison, but the system is intended to respond to maintain a desired temperature in the respective zones.
The system depicted in FIG. 11 is intended to regulate the atmosphere in the furnace F. This is essential for the heat treatment of the components C. The pocket wheel 18 rotates in an endothermic atmosphere which is controlled to a desired carbon potential so that neither decarburization or carburization will occur during the heat treatment. An oxygen probe 56 is used to monitor the oxygen content and the temperature which is then converted to carbon potential in the atmosphere controller 57. The atmosphere controller 57 makes adjustments to the atmosphere by adding either enrichment gas from source 58 or dilution air from source 59 to the furnace through inlet ports 60.
Turning to FIG. 12, there is illustrated schematically a modified apparatus for heat treating a pair of components at the same time. While the furnace F-1 is indicated in phantom outline, the rotary wheel 61 is provided with a series of double pockets 62 on the periphery of the wheel 61. As shown, a pair of components located on the slide 63 are propelled by pusher means 64 into a pair of pockets that have been indexed, in the manner before explained, into a position to receive the components. After a pair of components have been moved by rotation of the wheel 61, they reach the location where a dual discharge chute 65 has its fingers 66 in position to lift the components off the centering lip elements so gravity can effect the discharge. The pair of components are directed into the plug quench press 52. The FIG. 12 apparatus is shown in schematic form with the understanding that the structural and operating means of the character previously described in the preceding views for processing a single line of components will be repeated in a suitable modification for handling more than one component at a time. For example, in order to shorten the text, the loading means of FIG. 4 enlarged for loading two components at one time can be employed for the pusher means 64. The discharge means shown in FIGS. 5 and 6 when enlarged to handle two components at the same time can be employed for the discharge chute 65. The control system for FIGS. 10 and 11 include infrared sensors 67 and 68 at the loading position, infrared sensors 69 and 70 with a wheel home position slot 71, and a servo motor and resolver means 72 on the shaft 73 for the wheel 61.
It is contemplated that changes and modification may be made within the scope of the invention as set forth herein.
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A pocket wheel furnace having a furnace housing provided with a heat source in the side walls to project heat upon the components requiring heat treatment. The components are loaded into the pockets on the wheel at a first station and travel through the projected heat for the time needed to reach the heat treatment temperature before reaching a discharge station where the components are moved to a quench station. The travel time in the furnace is predetermined and is substantially equivalent for all components in a batch thereof.
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RELATED APPLICATION
This is a continuation-in-part of copending application Ser. No. 228,925 filed Jan. 27, 1981 entitled Needle with Opening Eye now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a needle intended for interlacing yarns, strands or flexible cords into an already known structure composed of a shank which is bent at its end to form a blade, defining an eye.
The needle of this type finds application particularly in the manufacture of reinforced multi-directional woven or knitted structures of revolution. Such reinforced structures are used after impregnation with an appropriate binding agent, to make structural assemblies of composite material which may undergo very severe mechanical and thermal stress, for example nozzles, radioelectric antenna, windows for space shuttles, turbine vanes, nose cones of re-entry bodies, armour-plating, etc.
Numerous process for weaving structures of revolution exist, and particularly processes for three-dimensional weaving, in which the circumferential and longitudinal yarns are connected by radial yarns. The needles usually used for making this connection are so-called sewing and/or knitting needles. The former, such as used in French Patent Application No. 76 02943 of Feb. 3, 1976, comprise a closed eye. They carry a stitching yarn knotted with a second yarn past, via a shuttle, in a loop of the first yarn. The latter are latch needles such as described in French Pat. No. 75 20117 of June 26, 1975 and in U.S. Pat. No. 4,149,477.
A latch needle engages, with the latch open, in the structure being woven, hooks a yarn and returns it through the structure, latch closed, the connection between yarns being made by a chain stitch.
In the case of making reinforcements of any form on a woven structure mode on metal rods, the conventional latch needle as used in the above-mentioned patents comprises a head which is too large to be able to perform its function. Due to its constitution, the risks of untimely hooking of the yarns of the woven structure are multiplied not only in case of false maneuver, but also during normal use. Such a risk is run, for example, when the needle enters in the woven fabric, then moves back before its head has emerged on the opposite side. Furthermore, it is sometimes difficult to grip a large number of yarns or a yarn and/or a large strand of yarns with a latch needle, due to its size, insofar as the gripped yarns tend to escape before the latch closes again. If a large number of yarns is to be gripped, it is necessary to use a latch needle having a large-size point, but this leads to a certain fragility in this zone. On the other hand, in woven reinforcements adapted to withstand considerable mechanical and thermal stress, the textile structure most frequently used is a carbon filament or strand, which is very fragile and therefore easily damaged by the mobile latch.
SUMMARY OF THE INVENTION
To overcome the drawbacks of known needles, it is an object of the present invention to provide a needle, particularly adapted for making reinforcements in any form of multidirectional weaving. This needle, which is of the type indicated hereinabove, is characterized in that the end part of its shank is flattened on one side and is bent to form an elastic blade of which the flattened free end is normally applied in abutment against the shank to form the eye of the needle. The eye formed between the blade and the shank being normally closed, is openable by moving the end of the blade away from the shank by the elastic deformation of the blade under the action of an opener to allow yarns to be introduced in the eye thus opened.
A needle with an openable eye according to the present invention may be used in place of a latch needle, without having the drawbacks thereof. This comes from the fact that the eye of the needle is normally closed. This permits the needle to move in this state through a woven structure, in one direction as well as in the opposite direction, without any risk of hooking the yarns of the woven structure. The eye is opened by the opener only at the moment and at the spot where yarns are to be gripped by the needle, to be drawn for example through the woven structure, whilst a latch needle must pass through the woven structure with the latch open to seek yarns to be gripped, this being without possibility of moving back if necessary.
The above-mentioned elastic blade preferably comprises, near the end of the needle shank, a thin portion forming a hinge and facilitating its deformations when the eye is opened and closed.
The outer end of the blade is advantageously bevelled to ensure perfect slide, without risk of untimely hooking, of the needle having gripped yarns and moving back through a woven structure, drawing the yarns with it.
As to the extreme outer end of the shank forming the head of the needle, it is preferably shaped as a point so as to facilitate penetration of the needle in a woven structure, to grip yarns. The end of the shank may also offer a disk-shaped cavity in which engages the end of a metal rod which, previously incorporated in the woven structure, must be chased by the needle.
In conclusion, a needle with opening eye according to the invention avoids untimely hooking of the weaving material both during normal use and in the case of false maneuver. It enables a large number of yarns or a yarn of large diameter to be gripped and a very fragile yarn to be used without damaging it. It is easy to manufacture and its constitution is such that it may have as fine a head as is desired.
The invention will be more readily understood on reading the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows in elevation a needle with opening eye according to the invention, only the zone of the needle's eye being shown.
FIGS. 2 to 5 show part of a machine using the needle of FIG. 1, in various successive phases of operation.
FIGS. 6a to 6e schematically show how the needle according to the invention functions, in successive views corresponding to sections of the machine of FIGS. 3 to 5 along a plane parallel to the needle and perpendicular to the plane of the yarns manipulated thereby.
FIG. 7 shows in section, on the scale of FIG. 1, the head of a needle in a variant embodiment.
DESCRIPTION OF THE INVENTION
Referring now to the drawings, FIG. 1 shows an embodiment of a needle with opening eye according to the invention. This needle 1 comprises unitary one piece rectilinear shank 2 whose section is circular in the present example, but may be of any other form. The shank 2 may be of any length; it may be very long and reach one meter or more. This shank is provided in its terminal zone a thinner part 3 which is bent, beyond the head 4 of the needle, to form a flexible blade 5 abutting elastically by its end 6 on the shank 2, where part 3 of said shank begins. The blade 5 and part 3 of the shank 2 are formed with flat land faces lying in opposition to each other, and define a space 7 which constitutes the eye of the needle, which is normally closed. The tip end 6 of the blade 5 abuts against the land surface of the thinner part 3 thus providing a one piece unarticulated needle which is substantially straight, though the eye, has a generally smooth rounded exterior surface and is not substantially larger, in diameter, at the eye than at the shank. Further, the outer surface of the tip end 6 of the blade 5 is bevelled, as shown, so that the needle 1 can pass downwardly through a woven structure in the direction of arrow 9 without risk of untimely hooking of the yarns of said structure.
Using an opener of which an embodiment will be described hereinafter, it is possible to easily move the blade 5 away from the part 3 of the shank 2, so as to open the eye 7 at the level of the end 6 of said blade. This opening involves an elastic deformation of the blade 5, which is facilitated by the presence of a thin zone 8 which is formed not far from the head 4 of the needle 1 and which acts as a hinge. With the eye 7 of the needle being open, yarns may penetrate therein and be housed therein to be taken, after the eye has been closed, through a woven structure by the needle 1 moving in the direction of arrow 9. To allow the needle to return easily through the woven structure by an opposite movement, its head 4 has been shaped as a point 4', as shown.
FIGS. 2 to 6 illustrate an example of use of a needle according to the invention. FIG. 2 shows part of a machine for making a woven structure 10 through which a strand of yarns 11 is to be passed repeatedly in vertical direction. These yarns, three in number in the present example, are guided on arrival by a presenting device 12 offering three guide conduits 13. The strand of yarns 11, rising vertically on leaving the conduits 13 of the presenting device, is periodically subjected to the action of a horizontal push member 14 which drives the yarns towards the right (FIG. 3) with formation of a loop of suitable length and unwinding of the yarns, through the presenting device 12, in the direction of arrow 15 from a supply reserve (not shown).
A needle 1, formed in accordance with the needle described hereinabove, then descends through the woven structure 10 and passes behind the push member 14 and the yarns 11 leaving the presenting device 12, its eye 7 being closed. Its head 4 penetrates in a passage 16 made in a fixed piece 20, tapering due to the presence of an oblique wall 17 which the head 4 of the needle encounters and which pushes it slightly towards the right. This movement causes the penetration of a fixed knife 18 in the eye 7 of the needle 1 (FIGS. 3 and 6a), this knife forming, with the piece 20 and its passage 16, the opener mentioned hereinabove. The needle continues to descend (FIGS. 4 and 6b) and the part 3 of the shank arrives entirely below the yarns 11, whilst the eye 7 opens under the action of the knife 18.
The presenting device 12, which is mounted on a vertical pivot pin 19, then pivots about this pin and applies the yarns 11 against the shank of the needle (FIG. 6c). The push member 14 returns towards the left; the needle then beginning to rise again, these yarns penetrate in the open eye 7 (FIGS. 6d and 5) and are finally gripped in the eye of the needle and drawn in the form of a loop through the woven structure 10 (with concomitant reabsorption of the loop initially formed by the push member 14). The eye 7 was previously closed again by disengagement of the knife 18 on passage of the head 4 of the needle along the oblique wall 17.
FIG. 7 shows a variant embodiment in which the head 4 of the needle 1 comprises, not a point 4', but a cavity 4" whose shape is adapted to that of the end of the rods which the needle is possibly to push on descending through the woven structure.
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A needle for interlacing yarns, strands or the like in a multi-directional woven structure composed of a shank bent to form an elastic blade. The end of the blade is normally resiliently applied against the shank, so as to form the eye of the needle which is opened by moving the blade away from the shank by means of an opener. The yarn is thus inserted and the eye is allowed to close while the needle is moved.
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BACKGROUND
This invention relates to a novel device and method for determining the flow rate of thermoplastic materials. In particular, this invention relates to a device and method for determining flow rate which utilizes electronic circuitry to monitor the extrusion or displacement of a known volume of a thermoplastic sample and conveniently calculate the flow rate of said sample. More particularly, this invention relates to a novel device and method which automatically and instantaneously computes and displays with high precision the flow rate of thermoplastic samples run in an extrusion plastometer in accordance with American Society of Testing and Materials (ASTM) Method D1238. This invention also relates to other types of melt, liquid, or solution viscosity measurements in which a flow or efflux time is measured and for which a simple computational constant can be derived.
The melt flow rate or "melt index" of thermoplastics as determined by ASTM Method D1238 (Current edition approved Jan. 26, 1979; published February, 1979; originally published as D1238-65T; last previous edition D1238-73--hereby expressly incorporated herein by reference), or foreign counterparts, is universally employed as a specification or inspection property. As a result, the extrusion plastometer is widely used in polymer manufacturing plants, polymer fabrication plants, technical service, research and other laboratory installations the world over. More recently, a variety of plastometer configurations have been developed. Examples of such plastometers are Brown et al. (U.S. Pat. No. 3,807,221), Murphy et al. (U.S. Pat. No. 4,062,225) and Fuxa (U.S. Pat. No. 4,109,516).
In Procedure A of ASTM Method D1238, the operator manually cuts off portions of extrudates at specified time intervals and weighs them on a balance accurate to ±0.001 g. This procedure is time consuming, requires an expensive balance as an accessory, and is subject to errors in both collecting extrudates at exact time intervals and in the weighing step. The final result is calculated manually in accordance with the test method. Procedure B of ASTM Method D1238 involves the use of an automatically operated timer to determine the time required to extrude a known volume of polymer. The flow rate is then determined from the following relationship
Flow rate=F/t
where F is a numerical factor which takes into account the volume extruded, the size of the piston used to extrude or displace the polymer, and the density of the polymer melt; and t is the time taken to extrude the known volume. Values of F are different for each polymer and are well known in the art. The method still involves a manual calculation of the result and is subject to the potential incorrect entry of the numerical factor each time the calculation is repeated. Precision may also be limited by the type of timing device used. Our invention overcomes the limitations of the currently-used procedures mentioned above through the use of a low cost microprocessor and supporting circuitry.
Previous attempts at an automatic flow rate measuring and method, most notably the Monsanto Automatic Capillary Rheometer, remain limited by the fact that the actual computation of flow rate must be performed each time by the user. In addition, such "automatic" devices are basically little more than sophisticated timers--the user is still required to read the timers and perform the subsequent calculations.
In contrast, the device and method of this invention requires only that the user input the numerical factor characteristic of the particular material being measured. All timing and control functions of the measurement, as well as all computational functions, are subsequently directed by a microprocessor and supporting circuitry. The flow rate is then displayed by means of the output device of choice.
The apparatus of this invention utilizes Procedure B of ASTM Method D1238. In accord with this method, the material to be measured is first preheated for a short period to prepare it for extrusion. A weighted piston of known surface area is then used to force material through a barrel and extrusion plastometer orifice of known dimensions. The measurement is based upon determining the time required to displace a known volume of material.
SUMMARY OF THE INVENTION
This invention is an improvement in the established methods of determining physical characteristics of thermoplastic materials. More specifically, in a method for determining the flow rate of a thermoplastic material in accord with Procedure B of ASTM Method D1238 using an extrusion plastometer, the improvement of the present invention comprises entering one or more numerical factor specified by said ASTM Method D1238 for said thermoplastic material into an input/output device capable of being read by a microprocessor, using one or more programmed microprocessors to (a) initiate an electronically timed interval when a change of state is detected in a switch designed to undergo a first change of state after displacement of said thermoplastic material begins in said plastometer; (b) check the status of said switch at predetermined intervals; (c) end said electronically timed interval when said switch undergoes a second change of state upon the displacement of a predetermined volume of said thermoplastic material; (d) determine the duration of said timed interval; and (e) calculate the flow rate for said thermoplastic material by dividing said factor by the duration of said timed interval, and displaying said flow rate in a convenient input/output device.
In addition, the present invention also provides an improved device for determining physical characteristics of thermoplastic materials. More specifically, in a device for determining the flow rate of a thermoplastic material in accord with Procedure B of ASTM Method D1238 using an extrusion plastometer, the improvement of the present invention comprises means for entering one or more numerical factors specified by said ASTM Method D1238 for said thermoplastic material into an input/output device capable of being read by a microprocessor; means for initiating an electronically timed interval when a change of state is detected in a switch designed to undergo a first change of state after displacement of said thermoplastic material begins in said plastometer; means for checking the status of said switch at predetermined intervals; means for ending said electronically timed interval when said switch undergoes a second change of state upon the displacement of a predetermined volume of said thermoplastic material; means for determining the duration of said timed interval; means for calculating the flow rate for said thermoplastic material by dividing said factor by the duration of said timed interval; and means for displaying said flow rate in a convenient input/output device.
Any means of starting and stopping the timing operation may be used. A readily available mechanical switch ("timer actuating switch") is described in detail as part of ASTM Method D1238. This switch is normally closed and is connected to a split-second timer. At some point after the extrusion begins, the switch changes state (opens) and the timer is started. The switch changes state again, (closes), and stops the timer, after a cylinder of the polymer of known length and diameter (and therefore, volume) is extruded or displaced. The operator then performs the flow rate calculation after reading the timer and looking up the appropriate numerical factor F for the material.
In accord with the method of this invention, a similar mechanical switch can be used. However, other sensing devices such as microswitches, light beam-photocell units, capacitance or inductance operated switches, and the like, can also be used. A normally open switch can also be used with suitable electronic or program modifications obvious to those skilled in the art. The switch signal is connected to the peripheral interface adapter (PIA) board.
In accord with our invention, the numerical factor pertaining to the material to be measured is input into the microprocessor by means of a convenient input/input device. Such devices can include thumbwheel switches, a keyboard, or magnetic tape--the choice in most cases being determined by the sophistication of the microprocessor and the expense of the additional peripheral equipment.
In one aspect, a set of four indicating binary coded decimal (BDC) thumbwheel switches function to enter the numerical factor used in the computation. Once set, no further manipulation of these switches is required unless the factor is to be changed to run a different type of polymer. These thumbwheel switches are connected to the PIA board through type 74153, or equivalent, multiplex chips to allow each switch's status to be read individually, because there are insufficient inputs to handle all switch leads simultaneously.
In one embodiment, the computational program can be stored on magnetic tape and then loaded in the 1K of random access memory (RAM) on the microcomputer board. In this aspect, the program need not be loaded again, except in case of a power failure, causing loss of the data in RAM. Alternatively, in the preferred embodiment the program can be permanently stored in a separate read only memory (ROM) chip which will be interfaced with suitable circuitry. In this aspect, the program can be permanently stored and there will be no need to load from magnetic tape, even in the event of power failure.
Once the extrusion interval has been timed as the interval between the two changes in state of the sensing switch, the factor is read by the microprocessor and the computation is performed. The result of the computation, the flow rate, is then displayed by means of a convenient input/output (I/O) device, such as an LED display or a printer.
A "reset" button is provided which consists of a momentary contact switch connected to the central processing unit (CPU) chip of the microprocessor, and functions to clear the previous computation in preparation for the next run.
The principal features of operation in accord with the preferred embodiment of the present invention are:
1. Pressing the reset button clears the result of the previous measurement, and prepares the timer and circuitry for the next measurement.
2. The run is begun by applying the required load to the piston of the extrusion plastometer, thereby starting the extrusion.
3. When the sensing switch changes state at the start of the measuring interval, an interrupt routine is initiated which checks the status of the switch at predetermined intervals.
4. A "debounce" routine is included to ignore any subsequent changes of state of the sensing switch for a suitable interval of 0.1 to 0.5 second. This tends to eliminate sensitivity to vibration and avoids false shutoff of the timing function caused by bouncing of the switch contacts.
5. When the measurement interval is complete and the sensing switch again changes state, the settings of the thumbwheel switches are read. The flow rate is calculated through the relationship
Flow rate=F/t
where F is the factor entered via the thumbwheel switches and t is the time measured.
6. The result is then displayed.
The worker skilled in the art will note that refinements are readily apparent. One such improvement would be to incorporate a means of signalling the end of a 5 minute "preheat" period as a convenience. In this embodiment, two displays would be in use: one to indicate the flow rate result, and the other to indicate the elapsed (preheat) time since the reset button was pressed. Such a display of the elapsed time after reset would serve to time the preheat period and signal the end of the preheat period and the start of the measurement run. This feature can be provided through a second interrupt program and can derive its time base from a crystal controlled oscillator on the microprocessor circuit board. Both this display and the one used to display the result can be multiplexed by the microprocessor to reduce the number of electronic components needed. The incorporation of a printer to provide a "hard copy" of the result on the display is also contemplated as well as provision to allow operation of several extrusion plastometers with one microcomputer unit, if desired.
The advantages of this apparatus also are readily apparent. It provides more precise results and eliminates several possible sources of operator error, eliminates the time required for manual computation and eliminates the need for a balance. With this instrument, a single technician can operate several extrusion plastometers simultaneously since it is not necessary for him to collect and weigh extrudates, or operate a timer or perform calculations. This would be of particular advantage in manufacturing installations. Its simplicity and low cost will allow it to be used with existing extrusion plastometers without modification.
This same apparatus can be adapted to many other types of viscosity measurements in which a flow time is measured and for which a suitable constant can be developed. Examples include measuring the viscosity of motor oils and other petroleum or synthetic liquids, paints, food products, solution viscosities of polymers, etc.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the microprocessor controller and associated circuitry in accord with the present invention.
FIG. 2 is a schematic diagram of the peripheral interface adaptor board used in conjunction with the controller board of FIG. 1 in accord with the present invention.
FIG. 3 is a block diagram of the method of operation of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to the drawings, FIG. 1 shows a schematic diagram of the preferred embodiment of the present invention. The unit shown uses a QIX, Inc. microcomputer which uses the MIK 6503 microprocessor controller, U9.
MIK is a single card microcomputer specifically designed for controller applications. Completed programs can be stored in either an on-board EPROM or PROM U8 for execution by MIK, providing a nonvolatile program store for controller applications. MIK has 16 input/output (I/O) lines, 50, which may be programmed as input or output ports. For output, on-board open collector drivers, U1, U2, U3, will sink up to 40 ma allowing direct driving of relays, power transistors, or LEDs from the MIK board without additional external circuitry.
MIK pinouts permit use of type 2704 or type 2708 erasable programmable read only memories (EPROM) for up to 1K bytes of program storage. Pin compatible programmable read only memories (PROM) may also be used with appropriate external connections on the board edge connector, 60.
The MIK microprocessor controller, U9, includes 128 bytes of random access memory (RAM) for use as scratch pad memory and storage of program variables. MIK also includes a programmable clock capability external to the 6503 microprocessor permitting timed interrupts of the 6503. In addition, MIK has an on-board +5 volt regulator, V1.
FIG. 1 is a schematic diagram of the MIK microprocessor controller board. MIK uses the 6503 microprocessor, U9, together with the 6532 memory, I.O, and timer array, U5, and necessary support circuitry. The on-board crystal controller oscillator, X1, provides an accurate source of timing. Debounce circuitry for the reset and nonmaskable interrupt (NMI) lines is also provided (U4 and its associated resistor/capacitor network).
As can be seen from FIG. 1, both buffered and unbuffered pinouts of the sixteen 6532 I/O lines 50 are provided to the MIK edge connector 60 permitting these lines to be used as inputs, or buffered or unbuffered outputs. Table 1 lists the various components and associated descriptions for the MIK board.
TABLE 1______________________________________COMPONENTS OF CONTROLLER BOARDCOM- COM-PONENT DESCRIPTION PONENT DESCRIPTION______________________________________U1 7407 Hex Buffer/ R6 1K +10% 1/4w Driver resistor (14 pins)U2 7407 Hex Buffer/ R7 3.3K +10% 1/4w Driver resistor (14 pins)U3 7407 Hex Buffer/ R8 330K + 5% 1/4w Driver resistor (14 pins)U4 556 Dual Timer R9 560 +10% 1/4w (14 pins) resistorU5 6532 Multifunction R10 560 +10% 1/4w Support Chip resistor (40 pins)U6 7404 Hex Inverter R11 560 +10% 1/4w Buffer Driver resistor (14 pins) R12 560 +10% 1/4w resistorU7 7408 Quad 2-Input R13 560 +10% 1/4w AND Gates resistor (14 pins)U8 PROM (24 pins) Cl 0.22f +10% 12wv(orEPROM) capacitorU9 6503 Microprocessor C2 0.22f +10% 12wv (28 pins) capacitorU10 74145 BCD to Decimal C3 10pf +5% Decoder capacitor (16 pins)V1 7805 3-Term Positive C4 1f Tantulum Voltage capacitor RegulatorR1 3.3K +10% 1/4w C5 1f Tantulum resistor capacitorR2 3.3K +10% 1/4w D1 IN914 Diode resistorR3 47K +10% 1/4w D2 IN914 Diode resistorR4 47K +10% 1/4w X1 1MHz Crystal resistorR5 1K +10% 1/4w resistor______________________________________
Table 2 lists the MIK edge connector pinouts. A0 through A7 and B0 through B7 are the sixteen 6532 I/O lines 50. A0B through A7B and B0B through B7B are the buffered versions of these lines.
TABLE 2______________________________________MIK EDGE CONNECTORPin No. Connection Pin No. Connection______________________________________1 C1K A B72 IRQ B B7B3 Reset C B64 NMI D B6B5 A0 E B56 A0B F B5B7 A1 H B48 A1B J B4B9 A2 K B310 A2B L B3B11 A3 M B212 A3B N B2B13 A4 P B114 A4B R B1B15 A5 S B016 A5B T B0B17 A6 U GND18 A6B V EPROM (U8) pin 1819 A7 W EPROM (U8) pin 1920 A7B X EPROM (U8) pin 2121 +V22 +5______________________________________
Note that EPROM U8 (or PROM) pins 18, 19 and 21 are also brought out to the edge connector 60 in FIG. 1. EPROM U8 (or PROM) pins 18, 19, and 21 are brought out to the MIK edge connector tabs V, W and X respectively to allow MIK to be used with either EPROM (types 2704 or 2708) or compatible PROMs. For use with type 2704 or 2708 EPROMs, these pinouts are connected as follows:
V (EPROM pin 18): Ground
W (EPROM pin 19): +12 volts
X (EPROM pin 21): -5 volts
The preferred embodiment of FIG. 1 employs a 1K EPROM type 2758 which requires only +5 volt inputs.
A typical PROM requirement (Signetics N82S141 4K PROM; TI SN74S474 4K PROM; TI SN74S478 8K PROM) is as follows:
V (PROM pin 18): +5 volts
W (PROM pin 19): +5 volts
X (PROM pin 21): Ground
The data sheet for the particular PROM selected should be checked for different requirements. The selection of EPROM or PROM components is discretionary with the user and dependent upon the various requirements of a particular application.
IRQ (edge connector pinout 2) is the timer interrupt request line from the on-board programmable timer in the 6532 support chips, U5. This line is connected to the 6503 microprocessor, U9, IRQ input. It is also brought out to the edge connector, 60, for potential timing of external events. The pin is normally high with a low indicating an interrupt from the 6532 chip, U5.
RST (edge connector pinout 3) is the processor reset line. A +5 volt pulse (supplied, for example, through a momentary contact switch) will reset the 6503 processor, U9, and the 6532 support chip, U5. The processor will immediately jump to the location specified in the reset vector and begin code execution.
NMI (edge connector pinout 4) is the nonmaskable interrupt line to the 6503 microprocessor, U9. A +5 volt pulse on this line will cause the processor to jump to the location indicated in the NMI vector. Both the NMI and RST vectors are debounced on the MIK board by dual timer U4.
The MIK board is designed to operate from a single +5 volt supply except for extra voltage requirements of some EPROMs as already described. MIK has an on-board 7805 positive voltage regulator, V1, to supply +5 volts to the board components. The input to this regulator is brought out to edge connector pinout 21. Supplying +V to pin 21 will result in +5 volts being distributed to the board. The +5 volts is also brought out to edge connector pinout 22.
A peripheral interface adaptor (PIA) board comprising two parts, display segment 70 and input segment 80, as shown in FIG. 2, is employed to perform the I/O functions of the invention. A block diagram of the MIK controller and PIA board interfaced to comprise the system of the present invention is shown in FIG. 3. The edge connector 60 pinouts of the MIK controller, A, C, E, H, K, M, P and S are connected to PIA board display segment 70, as shown. Similarly, edge connector pinouts 5, 7, 9, 11, 13, 15, 17 and 19 of the MIK controller are connected to the edge connector of PIA board input segment 80.
The numbered pin connectors on the PIA board integrated circuits (IC1-IC4) have been deleted from the ICs in FIG. 2. The particular pin connections that should be made to duplicate the circuit of FIG. 2 will be obvious to those skilled in the art after examining the specifications of the ICs to be used. In particular, IC1 and IC2 of PIA board input segment 80 are both type 74153 integrated circuits with +5 volts on pin 16, and with pins 8, 1, and 15 connected to ground (for simplicity, the ground and +5 volt connections are not shown on FIG. 2). Considering the integrated circuits of PIA board display segment 70, IC3 is type 7447 integrated circuit with +5 volts on pins 16, 3, and 4 and pin 8 grounded; IC4 is type 74145 with +5 volts on pin 16 and pins 8 and 12 grounded. In addition, MIK controller edge connector 60 pinouts 22 and X are connected to +5 volts, pinouts U, V and W are connected to ground, and pinout 3 is connected to a reset switch.
The light emitting diodes (LED) of PIA board display segment 70, denoted DSP1-DSP8 in FIG. 2, are type 707; transistors Q1-Q8 are 2N3906 or equivalent; R1'-R7' are nominally 82 ohm, one-quarter watt resistors; R8-R15 are nominally 220 ohm, one-quarter watt resistors; and R16-R23 are nominally 1000 ohm, one-quarter watt resistors.
PIA board input segment 80 is shown in FIGS. 2 and 3 with thumbwheel switches, T1-T4. The numbered pin connections for each thumbwheel switch are also shown in FIG. 2, with the "common" pin C of each switch connected to ground. Alternative input means will be obvious to those skilled in the art. As there are insufficient inputs to the MIK controller to handle all thumbwheel switch leads simultaneously, T1-T4 are each connected to a multiplex chip (IC1 or IC2) so that each switch's status can be read individually by the MIK controller through edge connector 60.
While the MIK controller board of FIG. 1 has an on-board +5 v regulated power supply V1, an external regulated supply may be used if a higher rated supply is desired. In this event, the on-board supply V1 must be disabled or bypassed on edge connector 60. A Model EMA-5/6A regulated power supply manufactured by Power/Mate Corporation of Hackensack, N.J., is one example of such an external supply. Other comparable units can also be used--the main requirement is that the source provide regulated +5 volts direct current and be capable of delivering about 1.0 to 1.5 amps.
The components and circuitry described thus far correspond to the preferred embodiment currently in use. It will be obvious to those skilled in the art that substitutions of alternative equivalent components can be made without departing from the spirit of the invention.
Specifically, alternative EPROM components include Motorola's type 6834 and 2704, Natural Semiconductor's type 2708, and Intel's type 8708. PROM components that can also be used in accord with the method of this invention include Signetics' type N82S141, and Texas Instruments' type SN74S474 and SN74S478; while compatible ROMs include Intel's type 8308 and National Semiconductor's type DM77596. In addition, the 6532 microprocessor and EPROM chips can be replaced, for example, by a single 6530 chip made by Rockwell or MOS. Intel's 8085 microprocessor and 8155 RAM, I/O, Timer can be used in place of the 6503 and 6532 package. In general, those skilled in the art will recognize that numerous 4 bit, 8 bit or 16 bit processors can be used in conjunction with the method of the present invention.
With reference to the integrated circuits (IC1-IC4) of the PIA board, the 7400 series preferred is an industry standard produced by a large number of domestic and foreign manufacturers, including National Semiconductor Corp., Texas Instruments and Signetics. Low power consumption CMOS and Schottky-type TTL devices of equivalent function may also be used. The type 2N3906 transistors (Q1-Q8) used on the PIA board in display segment 70 is used in a switching mode. Such transistors can be replaced by well known low power, general purpose PNP transistor of equivalent or superior characteristics, with a power dissipation of about 300 milliwatts, including, for example, type 2N2222. The I/O display means (DSP1-DSP8) employed in the preferred embodiment, Data-Lit 707, may be replaced by any seven segment display LED (common anode) with similar electrical characteristics. The selection of alternates should be obvious to those skilled in the art and would include the MAN 72, MAN 4710, and FND 507.
In the operation of the preferred method and device of this invention, the timer actuating switch 85 on the extrusion plastometer is normally in a closed position before the start of a measurement. After the thermoplastic material is loaded into the extrusion plastometer, the operator presses the reset switch which clears both a result display and a timer display. The I/O ports 50 are initialized by the program and the program then starts the timer display counting by tenths of a minute to time the preheat period for the material. During this period, the program periodically checks the status of the actuating switch 85 and continues to display the preheat time until switch 85 opens. At the end of the desired preheat time, the operator simply applies the required load to the piston of the plastometer. As the piston displaces the material in the plastometer, the actuating switch 85 is opened, signalling the start of the measurement period. When switch 85 opens, the program extinguishes both displays to indicate a test is in progress.
A "debounce" routine is included in the program to ignore very short-term (≦1/2 sec.) contact bounce in switch 85. If the program detects re-closure of switch 85 in less than 1/2 sec., a false start has occurred and the program loops back to reinitialize all counters, restart and display the preheat timer, and again await a true switch 85 signal. If switch 85 remains open for greater than 1/2 second, the switch status is then periodically checked by the program through an interrupt routine which checks the status of the switch at 10 millisecond intervals. The time base is derived from a 1 MHz crystal controlled source X1. Upon re-closure of the actuating switch 85, signalling the displacement of the appropriate volume of material, the thumbwheel switches are read to input the numerical factor F for the particular material into the program. The program performs the necessary calculation of the flow rate by a BCD division algorithm and then displays the result. The result continues to be displayed until the reset switch is again pressed. As noted in FIG. 2, a permanent decimal point is provided between the fourth and fifth digits (DSP4-DSP5) of the result display and between the two digits (DSP7-DSP8) of the timer display. The LED forming the decimal point and a current limiting resistor R24 are connected between +5 volts d.c. and ground.
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Disclosed is a method and device for automatically and instantaneously computing and displaying with high precision the flow rate of thermoplastic samples run in an extrusion plastometer in accordance with American Society of Testing Materials (ASTM) Method D1238. The method and device comprise using a microcomputer and related circuitry to monitor and control the measurement process and subsequently compute the resulting flow rate.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sewing machine, and more particularly to an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine.
[0003] 2. Description of the Prior Art
[0004] In the existing sewing machines, there are many mechanisms used to convert circular motion into linear reciprocating motion, therefore, the control of the travel of the presser feet has great influence on sewing quality. Different presser feet are designed to meet different sewing needs, which require the presser foot to have different travels, for example: when buttons are sewed, the presser foot should be specially designed in such a manner that one end of the presser foot is fixed on one end of the presser foot shaft, and the structure of the presser foot which presses the cloth can move along with the cloth. The corresponding total travel of the presser foot, as shown in FIG. 1 , includes a first travel X 1 starting from a start point X 11 and ending at an end point X 12 along the long side of the button hole, a second travel Y 1 in the horizontal direction starting from a start point Y 12 and ending at an end point Y 22 , a third travel X 2 starting at a start point X 21 and ending at an end point X 22 , and a fourth travel Y 2 starting at a start point Y 21 and ending at an end point Y 22 . When the presser foot is located at the start point X 11 of the first travel X 1 , the first sensing electrode of the travel sensor in the sewing machine will be turned on to make the sewing machine sew the long side of the button hole which starts from the start point X 11 and ends at the end point of the first travel X 1 . After moving to a position where the second sensing electrode is turned on, the presser foot will start moving horizontally along with the cloth from the start point Y 21 of the fourth travel Y 2 to the end point Y 22 and then directly turns to the start point X 21 of the third travel X 2 for performing the sewing operation along the third travel X 2 and finally turns to the start point Y 21 of the fourth travel Y 2 for performing the sewing operation along the fourth travel until reaching the start point X 11 of the first travel X 1 .
[0005] After the sewing machine is used for a period of time, some parts will become loose, hence, the positions where first and the second sensing electrodes are turned on are often different from the correct positions of the presser foot, which will produce a defective button hole, for example, as shown in FIG. 1-1 , the two long sides of the button hole are different in length.
[0006] To solve the above problem, the positions where the first and the sensing electrodes of the travel sensing apparatus are turned on and the positions of the presser foot are designed to be adjusted, so that the start point of the respective travels of the presser foot can be controlled. However, since the corresponding adjusting structure is in the form of a cam, in the principle of mechanical designing, it is known that the cam may normally lead to non-single-direction displacement during the adjustment, in other words, when the displacement in the horizontal direction is needed to be adjusted, the displacement in the horizontal direction will be caused synchronously, thus leading to unneeded displacement, so that the travel of the presser foot is thus quite uncertain.
[0007] The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.
SUMMARY OF THE INVENTION
[0008] The primary objective of the present invention is to provide an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine, which utilizes the adjusting apparatus disposed on the swing arm and the pivot shaft which is the swinging center as well as the adjusting bolt of the adjusting apparatus and the elastic element that are disposed between the respective elements to horizontally adjust the relative position and the relation of the whole structure of the swing arm except the swinging center namely the pivot shaft, and immediately position the elements after adjustment. By such arrangements, the swing arm can be accurately brought into contact with the sensing portions of the travel sensing apparatus without complicated adjustment.
[0009] The secondary objective of the present invention is to provide an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine which utilizes the elastic element and the adjusting bolt disposed between the swing arm and the adjusting apparatus to maintain the relevant elements in the optimal elastic prestress state, namely in the optimal pressing state, thus achieving the objective of maintaining the whole structure in the optimal stable state.
[0010] The third objective of the present invention is to provide an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine in which the adjusting apparatus is directly mounted on the swing arm and the pivot shaft without any complicated structure or cam, so the assembly of the whole structure is simple, convenient and quick.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic view of a conventional travel for sewing a button hole
[0012] FIG. 1-1 is a schematic view showing that the start and end points of the travel for swing the button hole have error;
[0013] FIG. 2 is a partial exploded view of an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine in accordance with a first embodiment of the present invention;
[0014] FIG. 3 is a planar assembly view of the adjusting structure for a swing arm and a swinging center that control travel of a sewing machine;
[0015] FIG. 4 is a planar operational view of FIG. 3 ;
[0016] FIG. 5 is another planar operational view of FIG. 3
[0017] FIG. 6 is a partial exploded view of an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine in accordance with a second embodiment of the present invention;
[0018] FIG. 7 is a planar assembly view of FIG. 6 ;
[0019] FIG. 8 is a planar assembly view of an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine in accordance with a third embodiment of the present invention; and
[0020] FIG. 9 is a planar assembly view an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine in accordance with a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.
[0022] Referring to FIG. 2 showing an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine in accordance with a first embodiment of the present invention, the sewing machine includes a suspension arm 100 which is provided at a free end thereof with a presser foot shaft 10 and a fixing rack 20 adjacent to the presser foot shaft 10 . The fixing rack 20 is formed by bending a plate-shaped element and provided with a travel sensing apparatus A in the suspension arm 100 . The travel sensing apparatus A includes a sensor 30 , and a swing arm assembly B which is moved by a presser foot 11 disposed at a bottom of the presser foot shaft 10 . The swing arm assembly B includes a main body 40 for turning on/off the sensor 30 , and a sliding element 50 which is vertically and movably inserted in the main body 40 . A first end of the sliding element 50 is inserted in a bottom end of the main body 40 while a second end of the sliding element 50 protrudes toward the presser foot 11 to a height where the sliding element 50 can be moved by the presser foot 11 when the presser foot 11 horizontally moves to the start and end points of the travel. Since such structures are conventional, no further explanations are provided herein.
[0023] The sensor 30 includes a first sensing portion 31 , a second sensing portion 32 and a movable induction portion 33 disposed between the first and the second sensing portions 31 . The first sensing portion 31 , the second sensing portion 32 and the induction portion 33 are in the form of a metal sheet electrode. Each of the first sensing portion 31 , the second sensing portion 32 and the induction portion 33 is connected to a computer through a wire 34 . The induction portion 33 can be moved by the main body 40 of the swing arm assembly B in such a manner that the induction portion 33 can move toward any one of the two sensing portions 31 , 32 when the presser foot 11 moves to the start and end points of the travel to push the sliding element 50 and rotate the swing arm 40 . Besides the metal sheet electrodes, the first sensing portion 31 , the second sensing portion 32 and the induction portion 33 in the present embodiment can also be in the form of a photosensitive interrupt sensing element.
[0024] The fixing rack 20 is formed with a threaded hole 200 for locking a pivot shaft 21 . The pivot shaft 21 is pivotally connected to the swing arm assembly B, so that the whole swing arm assembly B can pivot about the pivot shaft 21 . The pivot shaft 21 includes a first end with an outer thread, a middle portion in the form of a cylinder, and a second end formed into a disk-shaped head. The middle portion of the pivot shaft 21 is bigger in outer diameter than the first end of the pivot shaft 21 but smaller in outer diameter than the second end of the pivot shaft 21 .
[0025] The present invention is characterized in that:
[0026] The main body 40 of the swing arm assembly B is provided at a bottom thereof with a pivotal portion 41 in alignment with the threaded hole 200 of the fixing frame 20 . The pivotal portion 41 is a rectangular frame and formed in a center thereof with a hollow rectangular horizontally-extending sliding groove 410 . The pivotal portion 41 is formed in a side surface thereof with an adjusting threaded hole 411 in such a manner that an adjusting apparatus 60 can be screwed into the adjusting threaded hole 411 to perform the adjustment.
[0027] The pivotal portion 41 includes a first side 412 , a second side 413 , a top end 414 and a bottom end 415 that are connected together. The pivotal portion 41 is centrally further provided in each of the top end 414 and the bottom end 415 with a fixing threaded hole 416 , 417 for insertion of the corresponding elements of the adjusting apparatus 60 .
[0028] The adjusting apparatus 60 includes a sliding block 61 which is square-shaped in cross section allowed to slide relative to the sliding groove 410 . The sliding block 61 is slidably disposed in the sliding groove 410 of the pivotal portion 41 in such a manner that its top and bottom end surfaces that are disposed in the sliding groove 410 abut against the top end 414 and the bottom end 415 of the pivot portion 41 . The sliding block 61 is centrally formed with a pivot hole 610 for insertion of the pivot shaft 21 . When the pivot shaft 21 is fixed in the threaded hole 200 , the pivot hole 610 of the sliding block 61 is just mounted on the pivot shaft 21 in such a manner that the sliding block 61 can rotate on the pivot shaft 21 .
[0029] The sliding block 61 is provided at an end exposed out of the sliding groove 410 with two opposite protruding ears 612 extending in an up and down direction, and each of the two opposite protruding ears 612 includes a horizontally-extending sliding slot 611 . A fixing element 64 in the form of a bolt is inserted through each of the sliding slots 611 and screwed into each of the fixing threaded holes 416 , 417 , so that the sliding block 61 can be fixed by screwing the fixing elements 64 and released to slide horizontally in the sliding groove 410 by unscrewing the fixing elements 64 .
[0030] The adjusting apparatus 60 is further provided with an elastic element 62 in the form of a coil spring and an adjusting bolt 63 . The elastic element 62 is disposed between the sliding groove 410 and the sliding block 61 . In the present embodiment, the elastic element 62 is disposed in the sliding groove 410 and elastically presses against the second side 413 of the pivotal portion 41 and a first end surface of the sliding block 61 . The adjusting bolt 63 is screwed in the adjusting threaded hole 411 in the first side 412 of the sliding groove 410 and inserted in the sliding groove 410 while pushing against a second end surface of the sliding block 61 . Before adjustment, as shown in FIG. 3 , the elastic element 62 which is elastically disposed between the sliding groove 410 and the sliding block 61 can provide an elastic prestress between the sliding block 61 and the adjusting bolt 63 .
[0031] When in adjustment, the relative position of the main body 40 with respect to the sliding block 61 and the pivot shaft 21 which is the swinging center of the whole swing arm assembly B can be adjusted by rotating the adjusting bolt 63 , so that the induction portion 33 connected to the main body 40 can be pre-adjusted to contact the first sensing portion 31 as shown in FIG. 4 . When the presser foot 11 starts moving, the sliding element 50 and the main body 40 will be driven to rotate around the pivot shaft 21 , and then the induction portion 33 will be moved to contact the second induction portion 33 to change a different travel. As shown in FIG. 5 , in other words, when the induction portion 33 is brought into contact with the first sensing portion 31 , the sewing machine in accordance with the present invention will sew the button hole along the first travel X 1 , and then when the induction portion 33 is brought into contact with the second sensing portion 32 , the sewing machine in accordance with the present invention will sew the button hole along the second travel Y 1 and then the third travel X 2 . After the induction portion 33 is brought into contact with the first sensing portion 31 again, the sewing machine in accordance with the present invention will sew the button hole along the fourth travel Y 2 .
[0032] With the above structures, the present invention can offer the following functions:
[0033] 1. Micro-adjustment, quick and high accuracy: with rotation of the adjusting bolt 63 and the pushing of the elastic element 62 , the relative position of the pivotal portion 41 of the main body 40 with respect to the sliding block 61 and the pivot shaft 21 can be quickly adjusted in such a manner that the main body 40 and the pivot shaft 21 only move horizontally relative to each other without causing height difference, so that when the presser foot 11 moves, the swing arm assembly B can accurately move the induction portion 33 to contact the first sensing portion 31 and the second sensing portion 32 , ensuring high accuracy and quality of sewing of the button hole.
[0034] 2. Stable overall structure: since the elastic element 62 is elastically disposed between the sliding groove 410 of the pivotal portion 41 of the main body 40 and the sliding block 61 of the pivot shaft 21 , the swing arm assembly B, the pivot shaft 21 and the adjusting apparatus 60 can be assuredly positioned, offering a stable overall structure.
[0035] Referring to FIGS. 6 and 7 which show an adjusting structure for a swing arm and a swinging center that control travel of a sewing machine in accordance with a second embodiment of the present invention, besides the protruding ears 612 , the sliding block 61 is further formed on the end exposed out of the sliding groove 41 with a laterally-extending L-shaped horizontally extending portion 613 . The horizontally extending portion 613 covers an opening of the sliding groove 410 and includes a threaded hole 614 in an end thereof extending across the first side 412 . An adjusting bolt 63 ′ is screwed into the threaded hole 614 and pushes against the first side 412 . An elastic element 62 ′ in the present embodiment is disposed between the first side 412 and the sliding block 61 and can also offer the above function.
[0036] As shown in FIG. 8 , the adjusting apparatus 60 can also be configured such that the sliding block 61 having an engaging portion 615 with continuous teeth is mounted on the pivot shaft 21 , and the pivotal portion 41 is formed on an inner surface of the top end 43 with an engaging portion 413 to be engaged with the engaging portion 615 of the sliding block 61 . The sliding block 61 is formed with a bigger disc-shaped head portion on an end thereof exposed out of the sliding groove 410 , so that the user can pull the head portion 616 in the adjustment to make the sliding block 61 move away from the sliding groove 410 along the axial direction of the pivot shaft 21 . After the pivotal portion 41 is moved to a proper position, the sliding block 61 will be re-installed on the pivot shaft 21 in the sliding groove 410 , and the engaging portion 615 will be re-engaged with the engaging portion 413 of the sliding groove 410 .
[0037] As shown in FIG. 9 , the sliding block 61 can also be in the form of a column and includes a sector engaging portion 617 to be engaged with the engaging portion 413 of the sliding groove 410 in the above embodiment. The pivotal portion 41 can be horizontally moved for adjustment by rotating the sliding block 61 .
[0038] In the present invention, between the sliding element 50 and the main body 40 is additionally provided an arc elastic plate 51 for producing an elastic frictional force when the sliding element 50 is moved in the main body 40 . The elastic plate 51 is disposed at one side of the bottom end of the main body 40 where the sliding element 50 is inserted, so that when the sliding element 50 is inserted in the main body 40 , the elastic plate 51 will elastically push against the sliding element 50 .
[0039] While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
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An adjusting structure for a swing arm and a swinging center that control travel of a sewing machine comprises an adjusting apparatus and corresponding structures cooperating with the adjusting apparatus. The adjusting apparatus is provided on the pivotal portion with a sliding groove and a sliding block that can horizontally slide with respect to each other. Between the sliding groove and the sliding block are further provided an adjusting bolt and an elastic element. By rotating the adjusting bolt, the relative position between the swinging center around which the whole swing arm pivots and the whole structure of the swing arm can be changed in the horizontal direction accurately and conveniently, thus assuredly adjusting the start point of the travel of the presser foot, achieving the objective of accursedly adjusting position of the travel sensing apparatus.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of Korean Patent Application No. 2010-0032408 filed on Apr. 8, 2010, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention relates to a hybrid key management method for robust SCADA systems in which group keys are created and are distributed using digital signatures in a SCADA system in which a master terminal unit (MTU), a plurality of sub-master terminal units (sub-MTUs), and a plurality of remote terminal units (RTUs) are sequentially and hierarchically structured, and a session key generation method.
[0004] The invention also relates to a hybrid key management method for robust SCADA systems in which public key based encryption is applied between an MTU and sub-MTUs and high performance symmetric key based encryption is applied between sub-MTUs and RTUS, and a session key generation method.
[0005] 2. Discussion of Related Art
[0006] Modern industrial facilities such as oil refineries, electric power generating plants, and manufacturing facilities generally have command and control systems. These industrial command and control systems are commonly referred to as Supervisory Control and Data Acquisition (SCADA) systems.
[0007] As demand for connecting SCADA systems to open networks increases, SCADA systems have become exposed to a wide range of network security problems. If a SCADA system is damaged through an attack, this system can have a widespread negative effect upon society. To prevent such attacks, many researchers have been studying the security of SCADA systems.
[0008] Many researchers have proposed key management schemes for SCADA systems. Key establishment for SCADA systems (SKE) and a SCADA key management architecture (SKMA) have both been proposed, and two schemes were recently proposed—Advanced SCADA Key Management Architecture (ASKMA) and Advanced SCADA Key Management Architecture+ (ASKMA+).
[0009] The ASKMA scheme has been proposed in Korean Patent Application No. 10-2010-0006103 (hereinafter, Prior Art 1), filed by the applicant of the present invention, titled “Efficient Key Management Method for SCADA Communications”. Prior Art 1 relates to a shared key management method for SCADA communications in which shared keys of a group key are generated in a tree structure and remote terminal units or sub master terminal units share the shared keys of their ancestor nodes and descendent nodes of the nodes corresponding to themselves, and a session key generation method. In particular, the group keys of a SCADA system is generated in a binary tree structure, and all the shared keys of the on-path nodes from an intermediate node to a root node are updated if the shared key of the intermediate key is updated. The shared keys of the on-path nodes are updated by their own shared keys and the shared keys of off-path child nodes.
[0010] However, previous studies do not appropriately consider availability. That is, they do not have a solution for the case when the main device breaks down. In addition, since many SCADA devices are remote from the control center, they are physically insecure. Therefore, the devices need to periodically update the security keys stored therein. However, the computation and communication costs of this update process increase as both the number of vulnerable devices and keys increase, so SCADA systems need to reduce the number of keys transmitted for security and efficiency.
[0011] Hereinafter, the cryptographic security requirements for SCADA systems will be discussed in more detail. They have been rebuilt based on standards and reports.
[0012] 1) Access control: A SCADA system should uniquely identify and authenticate organizational users and devices.
[0013] 2) Availability: The availability of a SCADA system is more important than confidentiality, because an unavailable SCADA system can cause physical damage or threaten human life. Usually, SCADA systems employ backup devices, because they should be designed to be always on. If the main device breaks down, it should be replaced with a backup device as soon as possible.
[0014] 3) Confidentiality: The data transmitted between nodes should be protected by encryption.
[0015] 4) Cryptographic key establishment and management: When cryptography is required and employed within a control system, the organization establishes and manages cryptographic keys using automated mechanisms with supporting procedures or manual procedures.
Broadcasting/Multicasting: Most SCADA systems include some form of broadcast capability. Because the SCADA system can send important messages such as “emergency shutdown” by broadcast capability, the broadcast messages should be protected. Backward secrecy (BS): Guarantees that a passive adversary who knows a subset of group keys cannot discover preceding group keys. Group key secrecy (GKS): Guarantees that it is computationally infeasible for an adversary to discover any group key. Forward secrecy (FS): Guarantees that a passive adversary who knows a contiguous subset of old group keys cannot discover subsequent group keys. Key freshness: RTUs are remote from the control center. The location of the RTU makes them physically insecure, so the keys in RTUs should be updated within a reasonable amount of time. Perfect forward secrecy (PFS): Perfect forward secrecy is the property that ensures that a session key derived from a set of long-term public and private keys will not be compromised if one of the private keys is compromised in the future.
[0022] 5) Integrity: It is critical that messages between nodes are not tampered with, and that no new message is inserted since message modification and injection can cause physical damage. Therefore, the SCADA system should ensure the integrity of the transmitted message.
[0023] 6) Public key infrastructure: The organization issues public key certificates under an appropriate certificate policy or obtains public key certificates under an appropriate certificate policy from an approved service provider.
[0024] 7) Number of keys: Since many SCADA system devices are remote from the control center, they are physically insecure. Therefore, the devices need to periodically update the security keys stored therein. In addition, if a device has many keys and the device is compromised, other devices which have those keys also become vulnerable. Therefore, each device which has keys must perform the update process. Since the computation and communication costs of this update process increase as both the number of vulnerable devices and keys increases, SCADA systems need to reduce the number of keys stored on each device for security and efficiency.
[0025] Hereinafter, the performance requirements and network configuration requirements of SCADA systems will be described in more detail.
[0026] First, a SCADA system needs to interact with devices in real time. Conventionally, a proposed architecture for SCADA communications must match the shortest time delay requirement of no more than 0.540 seconds.
[0027] Generally, a SCADA communication link operates at low speeds such as 300 to 19200 baud. In the modbus implementation guide, the default baud rate is 19200 and if that cannot be implemented then the default baud rate is 9600. Therefore, it is preferable to assume a required rate of 9600 baud.
[0028] When the SCADA system was first developed, the system architecture was based on a mainframe. Remote devices communicated directly with the MTU by serial data transmission. The second generation SCADA systems took advantage of developments and improvements in systems miniaturization and local area networking (LAN) technology to distribute the processing load across multiple systems. Thus, when a local MTU or human machine interface (HMI) malfunctioned, the device could be promptly replaced. Therefore, it is preferable to assume that a SCADA system's topology is second generation.
SUMMARY OF THE INVENTION
[0029] The prevent invention has been made in an effort to solve the above-described problems associated with the prior art, and an object of the invention is to provide a hybrid key management method for robust SCADA systems in which group keys are created and are distributed using digital signatures in a SCADA system in which a master terminal unit (MTU), a plurality of sub-master terminal units (sub-MTUs), and a plurality of remote terminal units (RTUs) are sequentially and hierarchically structured, and a session key generation method.
[0030] It is another object of the invention to provide a hybrid key management method for robust SCADA systems in which public key based encryption is applied between an MTU and sub-MTUs and high performance symmetric key based encryption is applied between sub-MTUs and RTUS, and a session key generation method.
[0031] According to one aspect of the invention, there is provided a hybrid key management method for a supervisory control and data acquisition (SCADA) system in which a master terminal unit (MTU), a plurality of sub-master terminal units (sub-MTUs), and a plurality of remote terminal units (RTUs) are sequentially and hierarchically structured, the hybrid key management method comprising the steps of: (a) creating, by the MTU and the sub-MTUs, their own secret numbers and making and exchanging digital signatures; (b) creating, by the MTU, group keys; and (c) distributing, by the MTU, the group keys to the sub-MTUs and encrypting and decrypting the group keys using the secret numbers.
[0032] Step (c) may comprise the steps of: (c1) raising, by the MTU, the group keys to the power of the product of its own secret key and the secret keys of the sub-MTUs and transmitting the raised group keys to the sub-MTUs; and (c2) decreasing, by the sub-MTUs, the raised group keys in proportion to the inverse power of the product of their own secret keys and the secret key of the MTU to obtain the group keys.
[0033] The hybrid key management method may further comprise the step of: (d) distributing, upon joining of a new sub-MTU (hereinafter, joining terminal), a group key to the joining terminal. Here, step (d) may comprise the steps of: (d1) creating, by the joining terminal, its own secret number; (d2) encrypting, by the MTU and the joining terminal, their secret numbers using a certificate and exchanging the secret numbers; and (d3) transmitting, by the MTU, the group key to the joining terminal using the same method as step (c).
[0034] The hybrid key management method may further comprise the step of: (e) redistributing, upon leaving of at least one sub-MTU, the group keys. Here, step (e) comprises the step of: (e1) recreating the group keys by the MTU; and (e2) transmitting, by the MTU, the recreated group keys to the sub-MTUs which have not left according to the same method as step (c).
[0035] The hybrid key management method may further comprise the step of: (f) replacing, upon exchange of the at least one sub-MTU (hereinafter, exchanged terminal) with another sub-terminal, the group key. Here, step (f) may comprise the steps of: (f1) recreating the group keys and transmitting the recreated group keys to the sub-MTUs that have not been exchanged according to the same method as step (e); and (f2) transmitting the recreated group keys to the exchanged terminal by the MTU according to the same method as step (d).
[0036] The terminals may verify the secret numbers of their counterparts using the certificates of their counterparts.
[0037] The secret numbers may be created by raising generators of a subgroup of an algebraic group to the power of random numbers which are created at random and pertain to the algebraic group.
[0038] The secret numbers may be created by applying Equation 1.
[0000] Secret number=g ri mod p, Equation 1
where r i εZ q is a random number of a terminal (i=0 in case of an MTU and i=[1,m] (m is the number of sub-MTUs) in case of a sub-MTU), g is a generator of a subgroup of an order q, and p is a prime number satisfying p=k·q+1 for a given small number kεN.
[0040] An intermediate key IK i may be obtained by raising a group key K g to the power of g r o r i in Equation 2 and a group key Kg is obtained by decreasing a group key (or intermediate key) IK i to the inverse power of g r o r i in Equation 3.
[0000] IK i =( K g ) g r o r i mod p Equation 2
[0000] K g =K g r o r i /g r o r i g mod p Equation 3
[0041] The group keys may have a tree structure. The tree structure may have a tree of an n th order from the root node corresponding to the MTU and the intermediate nodes corresponding to the sub-MTUs. The descendent nodes of the intermediate nodes may have binary trees. The leaf nodes of the binary trees may correspond to the RTUs connected to the sub-MTUs of the intermediate nodes.
[0042] According to another aspect of the invention, there is provided a session key generation method using a hybrid key of a supervisory control and data acquisition (SCADA) system in which a master terminal unit (MTU), a plurality of sub-master terminal units (sub-MTUs), and a plurality of remote terminal units (RTUs) are sequentially and hierarchically structured, the session key generation method comprising the steps of: (a) creating group keys in a tree structure by the MTU, the tree structure having a tree of an n th order from the root node corresponding to the MTU and intermediate nodes corresponding to the sub-MTUs, child nodes of the intermediate nodes having binary trees, and leaf nodes of the binary trees corresponding to the RTUs connected to the sub-MTUs of the intermediate nodes; (b) distributing the group keys to the sub-MTUs and the RTUs by the MTU and receiving and storing, by the sub-MTUs and the RTUs, the group keys of the ancestor nodes and descendent nodes of the nodes corresponding thereto; (c) selecting a node of the tree structure and creating a session key for communications with a sub-MTU or an RTU corresponding to the descendent node of the selected node as a group key of the selected node; and (d) in step (b), creating, by the MTU and the sub-MTUs, their secret numbers and digitally singing and exchanging the secret numbers, the group keys being encrypted and decrypted by the secret numbers to be distributed.
[0043] Session keys may be created by hashing values obtained by combining the group keys, timestamps, and sequence numbers.
[0044] According to the invention, a replace protocol which is available and by which the number of keys stored in an MTU is reduced can be supported by applying public key based encryption between the MTU and sub-MTUs and by applying high performance symmetric key based encryption between sub-MTUs and RTUS
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The above and other objects, features and advantages of the invention will become more apparent to those of ordinary skill in the art by describing in detail an exemplary embodiment thereof with reference to the accompanying drawings, in which:
[0046] FIG. 1 is a view illustrating an exemplary SCADA system for carrying out the invention;
[0047] FIG. 2 is a view illustrating an exemplary structure of a SCADA system according to an embodiment of the invention;
[0048] FIG. 3 is a flowchart of a hybrid key management method for a SCADA system according to an embodiment of the invention; FIG. 4 is a view exemplifying a tree structure of group keys created according to an embodiment of the invention;
[0049] FIG. 5 is an illustrative example of a join protocol according to an embodiment of the invention;
[0050] FIG. 6 is an illustrative example of a leave protocol according to an embodiment of the invention;
[0051] FIG. 7 is an illustrative example of a replace protocol according to an embodiment of the invention;
[0052] FIGS. 8A and 8B are views exemplifying a total time delay according to an embodiment of the invention; and
[0053] FIGS. 9A to 9C are views comparing the number of keys stored in an MTU and the total computation time.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0054] Hereinafter, exemplary embodiments of the invention will be described below in detail with reference to the accompanying drawings.
[0055] In the description of the embodiments, the same elements are denoted by the same reference numerals and will not be repeatedly described.
[0056] First, an exemplary SCADA system for carrying out the invention will be described with reference to FIG. 1 .
[0057] As can be seen in FIG. 1 , the SCADA system for carrying out the invention includes a human-machine interface (HMI) 10 , a master terminal unit (MTU) 21 , a plurality of sub-master terminal units (sub-MTUs) 22 , and a plurality of remote terminal units (RTUs) 23 . In particular, the MTU 21 , the sub-MTUs 22 , and the RTUs 23 have a sequentially hierarchical structure.
[0058] The HMI 10 shows process data of an infrastructure facility to a manager. The manager monitors and controls the infrastructure facility through the HMI 10 . For this purpose, the HMI 10 includes a terminal unit having a computing function.
[0059] The RTUs 23 are terminal units which are installed directly at infrastructure facilities to collect and transmit process data and perform control instructions. Generally, the infrastructure facilities to which the SCADA system is applied are distributed across a wide range of regions, so the RTUs 23 are also spaced apart from each other.
[0060] The sub-MTUs 22 communicate with specific RTUs 23 and control the RTUs 23 . The MTU 21 collects and controls process data as a whole. That is, the MTU 21 controls the sub-MTUs 22 and monitors and controls the RTUs 23 through the sub-MTUs 22 .
[0061] Session keys are used to allow the MTU 21 , the sub-MTUs 22 , and the RTUs 23 to perform encrypted communications with each other. That is, a session key is generated between a transmitting terminal and a receiving terminal and then is shared by the terminals. The transmitting terminal encrypts a target message with the session key and then transmits it, and the receiving terminal receives the encrypted message and then decrypts it with the session key.
[0062] The session keys are used in specific sessions and a new session key is used for each session. Even if a session key is exposed, other sessions are secure. However, the session keys are generated using keys shared by the terminals. That is, the session keys are generated by hashing the keys shared by the terminals and timestamps. Thus, it is most important to manage keys for secure communications.
[0063] In the hybrid key management method for robust SCADA systems according to the embodiment of the invention, keys are managed in two hierarchies as a whole by the MTU 21 . That is, according to the embodiment of the invention, the MTU 21 generates and transmits a group key to the sub-MTUs 22 . The MTU 21 mainly manages the common key.
[0064] Meanwhile, if a sub-MTU 22 is deleted from or added to the SCADA system, all the keys shared by the sub-MTUs 22 should be updated to protect the keys. Thus, the MTU 21 updates the keys and transmits them to the sub-MTUs 22 .
[0065] Next, the notations and system structure for describing the hybrid key management method for SCADA systems according to the embodiment of the invention will be described with reference to FIG. 2 .
[0066] The following notations are used throughout the specification.
m: the number of sub-MTUs r: the maximum number of RTUs per sub-MTU GM: a nonempty set of nodes. This set is divided into two disjoint subsets MT and RT, i.e. GM=MT RT RT: RT={RT 1 , . . . , RT m·r } is the set of RTUs MT: MT={MT 0 , . . . , MTm} is the nonempty set of an MTU or sub-MTUs g: generator of the subgroup of an order q p: a prime number such that p=kq+1 for some small k N q: the order of the algebraic group r i : MT i 's random number r i Z q IKi: MTi's intermediate key K k k,j : MT k 's j th key at a level i in a binary tree
[0078] As can be seen in FIG. 2 , a CKD protocol, an Ioulus framework and a logical key structure are implemented. The proposed protocol has two parts MTs and RTs. MTs make a group key by the CKD protocol and RTs are constructed in a logical hierarchy structure.
[0079] Each RT i knows keys from a leaf node to an intermediate node as shown in FIG. 2 . Each MT i (i≠0) knows all keys which are on the path from the leaf node to the root node. The MT and RT are connected through the Iolus framework. The MT 0 (MTU) plays the role of a group security controller (GSC). Thus, the MT 0 manages the entire group and the group key between the MT 0 and MT i (1≦i≦m). The MT i (1≦i≦m) plays the role of a group security intermediary (GSI). It manages the subgroup key of its subgroup consisting of rRTs. The architecture of RT and connection of RT and MT are the same as in the ASKMA+protocol.
[0080] Now, the hybrid key management method for SCADA systems according to the embodiment of the invention will be described with reference to FIGS. 3 to 6 .
[0081] The key management method according to the embodiment of the invention comprises an initialization step S 10 , a step S 20 of updating keys when a sub-MTU 22 is added or deleted, a step S 30 of updating keys when the sub-MTU 22 or the MTU 21 is replaced with reserve equipment.
[0082] First, the MTU 21 creates a tree structure of keys (S 10 ). As can be seen in FIG. 4 , the root node 31 of the tree structure corresponds to the MTU 21 . The intermediate nodes 32 correspond to the sub-MTUs 22 , and the leaf nodes 34 correspond to the RTUs 23 .
[0083] Meanwhile, an n th order tree is provided between the root node 31 and the intermediate nodes 32 .
[0084] A binary tree is provided between each intermediate node 32 and its leaf nodes 34 . The nodes between the intermediate nodes 32 and the leaf nodes 34 will be called “general nodes” 33 below.
[0085] An example of a method of creating a group key in a tree structure is as follows.
[0086] First, the MTU 21 selects a random number r 0 computes g r o mod p|, digitally signs it, and transmits it to the sub-MTUs 22 . After each sub-MTU 22 which has received the message checks the validity of the digital signature and selects a random number r i if the digital signature is valid, it computes g r i mod p, digitally signs it, and transmits it to the MTU 21 . Here, i is the index number of a sub-MTU 22 and r i is a random number which satisfies r i εZ q . Here, q is the order of an algebraic group and p is a prime number satisfying p=kq+1 for a small positive integer K.
[0087] Next, the sub-MTUs 22 and the MTU 21 compute g r 0 r i mod p (iε[i,m]). Here, m represents the number of sub-MTUs 22 .
[0088] Next, the MTU 21 checks the validity of the digital signature, selects a group key K g , computes IK i =K g r 0 r i g mod p|(iε[i,m]), and digitally signs it. The MTU 21 and the sub-MTUs 22 can compute them in advance.
[0089] Next, the MTU 21 digitally signs IK i (iε[i,m]) and transmits it to the sub-MTUs MTUs 22 . The sub-MTUs 22 compute K g =K g r 0 r i /g r 0 r i g mod p(iε[i,m]) to obtain group keys K g .
[0090] Next, details of the step S 20 of updating keys when a sub-MTU 22 is deleted from and added to the tree structure are as follows.
[0091] For the m sub-MTUs 22 , a method of having (m+1)th sub-MTU 22 newly join the group is as follows.
[0092] First, the MTU 21 digitally signs g r p mod p which has been created in step 10 , and then transmits it to a newly joining sub-terminal 22 . After the sub-MTU 22 which has received the message checks the validity of the digital signature, if the digital signature is valid, the sub-MTU 22 selects a random number r m+1 , computes g r m+1 mod p, digitally signs it, and transmits it to the MTU 21 . Here, m+1 is the index number of the newly joining sub-MTU 22 .
[0093] Next, the newly joining sub-MTU 22 and the MTU 21 compute g r o r m+1 mod p.
[0094] Next, the MTU 21 checks the validity of the digital signature, and if the digital signature is valid, the MTU 21 selects a new group key K′ g at random, computes IK′ i =(K′ g ) g r 0 r i mod p (iε[i,m]), and digitally signs it.
[0095] Next, the MTU 21 digitally signs IK′ i (iε[i,m]) and transmits it to the prior sub-MTU 22 and the newly joining sub-MTU 22 . The sub-MTU 22 computes K′ g =K′ g r 0 r i /g r 0 r i g mod p to obtain K′ g .
[0096] Although the random value r i basically should be updated all the time, r i is repeatedly used for efficiency as in “session cache mode” of SSL.
[0097] While the initializing protocol reuses r i S, since it uses exponentials to compute IK′, the group members cannot know g rori of other group members. This can be applied to leave protocols or replace protocols as well as join protocols.
[0098] FIG. 5 shows a simple illustrative example of a join protocol. Here, a new sub-MTU is MT 5 and m is 4. A detail of this example is as follows.
Step 1: MT 0 broadcasts g r 0 mod p generated in the initialization step to a new unit MT 5 with a digital signature. Step 2: The new unit MT 5 checks the validity of the digital signature, selects a random number r 5 , computes g r 5 mod p|, and sends it to MT 0 with a digital signature. Step 3: The new unit MT 5 and MT 0 compute g r 0 r 5 mod p. Step 4: MT 0 checks the validity of the digital signatures, generates a group key K g ′ which is a random value, computes IK i ′=(K′ g ) g rori mod p (iε[1,5]), and signs it. Step 5: MT 0 sends IK i ′ (iε[1,5]) back to MT i with a digital signature. Step 6: Upon receipt of the message, each member MT i (iε[1,5]) computes K g ′=K g g rori /g rori mod p.
[0105] Next, a method of updating the keys when the j th sub-MTU 22 leaves a group consisting of m sub-MTUs 22 is as follows.
[0106] First, the MTU 21 selects a new group key K g ′ at random, computes IK′ i =(K′ g ) g r 0 r i mod p (i≠j and iε[1,m]), and digitally signs it.
[0107] Next, the MTU 21 digitally signs IK i ′, and transmits the sub-MTUs 22 other than the leaving sub-MTU 22 . The sub-MTU 22 computes K′ g =(K′ g ) g r 0 r i /g r 0 r i mod p|(i≠j and iε[1,m]) to obtain K g ′.
[0108] FIG. 6 shows a simple illustrative example of a leave protocol, and a leaving sub-MTU is MT 4 and m is 4. Details of the example are as follows.
Step 1: MT 0 generates a new group key K g ′, computes IK′ i =(K′ g ) g r 0 r i mod p(i≠j and iε[1,3]), and signs it. Step 2: MT 0 sends IK i ′ (iε[1,3]) to MT i with a digital signature. Step 3: Upon receipt of the message, each member MT i (i≠j and i [1,3]) computes K′ g =(K′ g ) g r 0 r i mod p.
[0112] The RTU leave protocol performs the same procedure as the ASKMA+protocol.
[0113] Next, a step S 30 of updating keys when a sub-MTU 22 or the MTU 21 is replaced with backup equipment is as follows.
[0114] A replace protocol for replacement with backup equipment is provided to support the availability. If some units of the SCADA system break down, they should be replaced with backup equipment. In this case, the leave protocol and the join protocol are simultaneously performed. Thus, the replace protocol is a combination of the leave protocol and the join protocol.
[0115] If a sub-MTU MT a breaks down, MT a should be switched to a backup sub-MTU. A method of updating keys when a sub-MTU 22 (i=n) is replaced with backup equipment will be described.
[0116] First, the MTU 21 selects a new group key K g ′ at random, computes K′ g =K′ g r 0 r i /g r 0 r i g mod p (i≠j and i [1,m]), and signs it.
[0117] Next, the MTU 21 digitally signs IK i ′ and transmits it to the sub-terminals 22 except for the replaced sub-terminal 22 . The sub-MTU 22 computes K′ g =K′ g r 0 r i /g r 0 r i g mod p (i≠j and iε[1, m]) to obtain the group key K g ′.
[0118] Next, the MTU 21 digitally signs g r 0 mod p and transmits it to a backup sub-MTU 22 which will replace the sub-MTU 22 . The backup sub-MTU 22 which has received the message checks the validity of the digital signature, and if the digital signature is valid, the backup sub-MTU 22 selects a new random number r′ n , computes g r′ n mod p, digitally signs it, and transmits it to the MTU 21 .
[0119] Next, the backup sub-MTU 22 and the MTU 21 compute g r 0 r′ n mod p
[0120] Next, the MTU 21 checks the validity of the digital signature, and if the digital signature is valid, the MTU 21 computes |IK′ n =(K′ g ) g r 0 r′ n mod p and digitally signs it.
[0121] Next, the MTU 21 digitally signs IK′ n and transmits it to the prior sub-MTU 22 and the new sub-MTU 22 . The sub-MTU 22 computes K′ g =K′ g r 0 r′ n /g r 0 r′ n g mod p to obtain K′ g .
[0122] If the MTU 21 is replaced, the initialization step S 10 is performed again.
[0123] FIG. 7 shows a simple illustrative example of a replace protocol, and the broken unit is MT 4 and m is 4. Details of the example are as follows.
Step 1: MT 0 generates a new group key K′g, computes IK′ i =(K′ g ) g rori mod p|(i [1,3]), and signs it. Step 2: MT 0 sends (i [1,3]) to MTi with a digital signature. Step 3: Upon receipt of the message, each member MT i (i [1,3]) computes
[0000]
K
g
′
=
(
K
g
′
)
g
g
rori
/
g
rori
mod
p
.
Step 4: MT 0 sends g r 0 mod p to the reserve sub-MTU MT′ 4 with a digital signature.
Step 5: MT′ 4 checks the validity of the digital signature, selects a new random number r′ 4 , computes g 4′ 4 mod p, and sends it to the MT 0 with a digital signature.
Step 6: MT′ 4 and MT 0 compute g r 0 r′ 4 mod p|.
Step 7: MT 0 checks the validity of the digital signatures, generates a new group key K′g, computes IK′ 4 =(K g ) g r0r4′ mod p, and signs it.
Step 8: MT 0 sends IK′ 4 to MT′ 4 with a digital signature.
Step 9: Upon receipt of the message, MT′ 4 computes
[0000]
K
g
′
=
K
g
′
g
g
ror
4
′
/
g
ror
4
′
mod
p
.
[0133] Next, a method of generating a session key according to the invention will be described.
[0134] In this subsection, the data encryption algorithms for unicast, broadcast, and multicast are presented. For the freshness of the session key, a time variant parameter (TVP) is used. The TVP is a combination of a timestamp and a sequence number.
[0135] That is, the session keys is generated using a key shared by terminals which are to be communicated with each other. Thus, the generation, storage, and updating of the key follows the above-described method.
[0136] In unicast, the session key for data encryption is generated in the following equation.
[0000] SK U =H ( K h,j k , TVP ) Equation 1
[0137] Here, K h,j k is a leaf node′s key where h is a height of the tree. The data is encrypted with the session key SK U .
[0138] In broadcast and multicast, the session key for data encryption should be generated using shared information by every member. The generation of the session key for broadcast and multicast uses the following equation.
[0000] SK b =H ( K g , TVP )| Equation 2
[0139] Here, K g is a shared key among group members. That is, K g is a shared key among all group members or some members of the group.
[0140] Thus, an encryption session may be set through the key having the structure 30 .
[0141] Next, the period to update the keys of the RTUs according to the invention will be described.
[0142] Since RTUs are generally remote from the control center, they are physically insecure. Therefore, the keys stored in the RTUs need to be periodically updated. If the key update frequency is too short, a time delay in SCADA communications needs to be increased. Thus, a suitable key update period, which satisfies communication efficiency and security requirements, needs to be found. Thus, QoS function is defined in Equation 3 to find the period.
[0000] QoS=Ci+Si Equation 3
[0143] CI and SI stand for communication index and security index. CI is computed based on the time delay caused by updating the keys in the RTUs. Assume that T is the period of communication in the SCADA system and δ is the time delay caused by updating keys, CI is computed in Equation 4.
[0000]
CI
=
T
-
δ
T
Equation
4
[0144] Since the period to update the keys is inversely proportional to δ, Equation 4 is modified to Equation 5.
[0000]
C
I
=
T
-
δ
T
=
T
-
k
/
t
p
T
Equation
5
[0145] Here, k is a constant and t p is the time between updating the current and next keys.
[0146] SI is calculated by the probability of a successful attack upon the RTUs. Since a successful attack upon the RTUs is recognized as an independent event in real life, a Poisson process may be employed to express the event.
[0000]
(
λ
t
)
n
n
!
,
n
=
0
,
1
,
…
Equation
6
[0147] Here, n is the number of the events during the time(=t), and λ is the mean of the number of the successful attacks upon the RTUs. The security goal of the invention is that a successful attack upon the key in the RTUs should not occur between updating the current and next keys. So, Equation 7 is derived for n=0 and t=t p .
[0000] SI=e −λt p Equation 7
[0148] In the Poisson process, λ represents the mean of the number of every possible attack upon the SCADA network. However, the target of attacks may be restricted to the keys in the RTUs. Then, the reason for attacks may be separated into either a logical error of the scheme to update the keys in the RTUs or an error of implementation. Some examples of attacks caused by logical errors are forward secrecy, backward secrecy and so on. Attacks caused by an error of implementation may be separated into invasive attacks on RTUs and non-invasive attacks on RTUs. An example of an invasive attack on the RTUs is reverse engineering of the hardware module of the RTUs. An example of a non-invasive attack on the RTUs is a side channel attack or reverse engineering of the software in the RTUs.
[0149] SI is recalculated in Equation 8.
[0000] SI=e −(λ l +λ i +λ ni )t p Equation 8
[0150] Here, λ l is the mean of the number of successful attacks caused by logical errors, λ i is the mean of the number of successful invasive attacks and λ ni is the mean of the number of successful non-invasive attacks caused by an error in implementation. However, the invention has some logical errors according to the security analysis. So, λ l of the invention may be assigned to 0.
[0151] Finally, the QoS function may be expressed by t p .
[0000]
QoS
=
T
-
k
/
t
p
T
+
-
(
λ
l
+
λ
i
+
λ
ni
)
t
p
Equation
9
[0152] To maximize the QoS function, a differentiation of the Qos function at a t p should be 0.
[0000]
QoS
(
t
p
)
t
p
=
k
Tt
p
2
-
λ
l
+
λ
i
+
λ
m
-
(
λ
l
+
λ
i
+
λ
ni
)
t
p
Equation
10
[0153] Thus, the optimal period for updating the key in the RTUs may be found.
[0154] Next, the effect of the invention will be described in detail
[0155] The cost of the invention is estimated and analyzed. Here, we are interested in two aspects. (1) The communication time delay should be less than 0.540 seconds. (2) The number of keys stored in an MTU should be less than the previous schemes. The analysis environment is assumed to be as follows.
The number of MT: 33 The size of a Diffie-Hellman parameter p: 1024 bit The size of a Diffie-Hellman parameter q: 160 bit The runtime of exponentiation: 0.00008 s The runtime of RSA-1024 signing: 0.00148 s The runtime RSA-1024 verification: 0.00007 s The runtime AES-128/CBC: 0.000009 s The signature algorithm: RSA 1024 Signature The certificate format: X.509 v3
[0165] Here, Diffie-Hellman parameters p and q are chosen. For run time, Crypto++ 5.6.0 is referenced. RSA and X.509 v3 are also chosen since they are the most commonly used public key cryptosystem scheme and certificate format.
[0166] In general, the message size of a SCADA system is less than 1000 bits. Thus, the message encryption/decryption time is 0.000018 s. The group setup time is 0.00015 s because the group key setup phase has 1 exponentiation operation and 1 verification operation. Therefore, the sum of these values and transmission time is the total time delay.
[0167] FIG. 8 shows the total time delay according to an embodiment of the invention. The example of the invention satisfies the performance requirements because the total delay time is 0.333505 sec at 9600 baud.
[0168] In the invention, the number of keys stored in an MTU is less than that in the other schemes. In FIG. 9A , the number of keys stored in an MTU for SKE, SKMA, ASKMA, ASKMA+, and the proposed scheme is compared.
[0169] FIG. 9B compares the number of keys stored in an MTU (r=128).
[0170] FIG. 9C compares the total computational time based on the number of multicast target nodes with 5-kb messages (r=128 and m=4).
[0171] Next, the security analysis for the proposed scheme will be described.
1) Group key secrecy: the difficulty of an active attacker (Mallory) to compute the group key will be described. Mallory can eavesdrop on, insert, delete, or modify messages on the group communication, but she is not a group member and hence does not know any key, because our protocol relies on the Decision Diffie-Hellman assumption and the Discrete Logarithm Problem. Mallory cannot find any information about the group key and plaintext from ciphertext with non-negligible probability. Therefore, Mallory cannot do better than a brute force search. 2) Forward secrecy: It is assumed that Mallory was a group member during some previous time period and she knows a group key. When Mallory leaves the group, our scheme updates keys as discussed above. Hence, Mallory cannot do better than a brute force search, to compute the new keys. 3) Backward secrecy: When Mallory joins the group and receives a group key, Mallory might have recorded earlier data packets encrypted with previous keys, but the probability of Mallory deriving any previous group keys is negligible because our protocol uses a new group key when Mallory joins the group. Therefore, she cannot derive previous keys by any better means than a brute force search of negligible possibilities to update keys. 4) Key freshness: Session keys are made by hashing a time variant parameter and key. Because a cryptographically secure hash function is used, each section key is independent of the previous key. In addition, all encryption keys are replaced with a new key for each session. Therefore, our protocol guarantees key freshness. 5) Perfect forward secrecy: Perfect secrecy means that a passive adversary who knows a contiguous subset of old group keys cannot discover subsequent group keys. Since the proposed scheme does not have long-term secrets which are used for encryption, the attacker cannot discover subsequent group keys by any better means than a brute force attack. 6) Availability: The proposed scheme supports a replace protocol. The replace protocol operates when the main device breaks down and switches to a backup device allowing a SCADA system to operate continuously. Therefore, the proposed scheme provides availability.
[0178] It will be apparent to those skilled in the art that various modifications can be made to the above-described exemplary embodiment of the invention without departing from the spirit or scope of the invention. Thus, it is intended that the invention covers all such modifications provided they come within the scope of the appended claims and their equivalents.
|
Disclosed is a hybrid key management method for a supervisory control and data acquisition (SCADA) system in which a master terminal unit (MTU), a plurality of sub-master terminal units (sub-MTUs), and a plurality of remote terminal units (RTUs) are sequentially and hierarchically structured, the hybrid key management method comprising the steps of: (a) creating, by the MTU and the sub-MTUs, their own secret numbers and making and exchanging digital signatures; (b) creating, by the MTU, group keys; and (c) distributing, by the MTU, the group keys to the sub-MTUs and encrypting and decrypting the group keys using the secret numbers.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of photographic film and improving the surface characteristics thereof.
2. Description of the Prior Art
In the use of photographic films, problems frequently arise due to surface adhesion or friction. Especially, motion picture films and narrow films must possess good slip properties to assure satisfactory running in the camera and in projectors. To achieve this, special slip agents are used which, usually applied to the back side of the film, provide improved slip properties (i.e., reduce surface friction) of the material. Known lubricants, which have been proposed so far for this purpose, mostly belong to the group of waxes or wax-like compounds as well as silicon compounds. A summarizing discussion of these materials and their use as slip agents is found in J. Soc. Motion Picture Television Engn., 74 (1965) 297-307, especially on p. 304 ff.
Recently the problem of adhesion and friction has arisen also in the case of X-ray films. For modern diagnostic functioning and for angiography, so-called sheet film exchangers are used, with which X-ray films are moved in rapid sequence in the beam path of the X-ray tube and exposed and again taken out of the beam path. The picture sequences amount to up to 10 photographs per second. Here, the problem of adhesion and friction of the films against one another as well as on the magazine walls, etc., is of great importance. Similar problems arise also in films for taking photographs in video amplifying cameras as well as in ribbon-shaped material for cineradiography.
However, if one wishes to solve this problem with slip agents which were developed predominantly for coating on the emulsion-free back side of motion picture films, it is found that they are not suitable for X-ray films. Namely, they must be introduced in the X-ray emulsion on both sides or applied on top of it, which leads to additional difficulties. Thus, silicon compounds, for example, the dimethylpolysiloxane according to German Offenlegungsschrift No. 1,938,959 cause appreciable wetting disturbances in casting, when they are added to the protective films on the X-ray emulsions. These wetting disturbances are manifested also in the processing of the films through nonuniform and delayed development and fixing. Besides, this slip agent addition leads to marked turbidity of the developed films, which cannot be tolerated in X-ray materials. Compounds of the wax type, for example, cetyl palmitate according to the German Pat. No. 1,300,015, improve the friction value sufficiently only at higher concentrations and then also display marked turbidity. The fixing speed is also reduced. Besides, it is a particular disadvantage that both types of slip agents influence unfavorably the hardening of the photographic films, which prevents the processing of the X-ray films at elevated temperatures in modern roll developing machines.
Accordingly, the problem of the invention is to develop suitable slip agents, preferably for X-ray materials.
SUMMARY OF THE INVENTION
The above problem is now solved according to repeated units of the invention in that a polyester having the following general formula is used as slip agent in either or both outer surfaces of a photographic element:
--O--CO--(CH.sub.2).sub.n --CO--O--R--
in which:
n = 1-8 and R is selected from the following groups: ##STR1## wherein X and Y are independently selected from H and CH 3 , and m = 0-4; ##STR2## and
--C.sub.2 H.sub.4 --O--C.sub.2 H.sub.4 --.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polyester compounds of Table 1 have been found to be particularly suitable for use in the invention.
Table 1.______________________________________Com-pound mpno. n R = ° C Av.Mol.Wt.______________________________________1 2 (CH.sub.2).sub.2 95 15002 3 (CH.sub.2).sub.2 liquid 12153 4 (CH.sub.2).sub.2 35 14004 8 (CH.sub.2).sub.2 63 18455 6 (CH.sub.2).sub.3 63 7706 2 (CH.sub.2).sub.4 97 17007 8 (CH.sub.2).sub.4 62 29008 2 (CH.sub.2).sub.5 39 28109 1 (CH.sub.2).sub.6 89 440 10 4 CH.sub.2CH(CH.sub.3) liquid 890 11 2 CH.sub.2C(CH.sub.3).sub.2CH.sub.2 62 1725 12 4 CH.sub.2C(CH.sub.3).sub.2CH.sub.2 38 1500 13 8 φCH.sub.2C(CH.sub.3).sub.2CH.sub.2 liquid 2680 14 2 ##STR3## 108 2190 15 2 C.sub.2 H.sub.4OC.sub.2 H.sub.4 liquid 970 16 3 C.sub.2 H.sub.4OC.sub.2 H.sub.4 38 1115 17 4 C.sub.2 H.sub.4OC.sub.2 H.sub.4 liquid 1245 18 8 C.sub.2 H.sub.4OC.sub.2 H.sub.4 32 1185______________________________________
the symbol ##STR4## as used herein denotes a hydroaromatic group.
The compounds of the invention can be prepared easily from the corresponding aliphatic dicarboxylic acids and the aliphatic or hydroaromatic diols. Suitable synthesis procedures are found in Houben-Wehl, Methoden der organischen Chemie, Fourth Edition, Vol. XIV/2, p. 12 ff.
The addition of the polyesters of the invention to aqueous gelatin solution suitably is accomplished with the aid of dispersing processes. Depending on the melting point of the polyester, different dispersing processes are used: For polyesters liquid at room temperature, process I, for solid polyesters with melting points < 70° C., process II, and for higher-melting polyesters, process III.
Dispersing Process I
In 955 ml of water 30 g of gelatin are swollen and dissolved with stirring at a temperature of 50° C. To this solution are added 5 g of an 8% aqueous solution of Hostapon®T (sodium salt of oleic acid methyltauride) and 10 g of a liquid polyester of Table 1, for example, compound No. 17, and the mixture is dispersed for 5 minutes with a high-speed stirrer (10,000 rpm).
Dispersing Process II
In 950 ml of water 30 g of gelatin are swollen and dissolved with stirring at a temperature of 50° C. To this solution are added 10 g of a 10% aqueous saponin solution and 10 g of a solid polyester of Table 1 with a melting point < 70° C., for example, compound no. 8, and the mixture is heated to 70° C. with stirring. This mixture is then dispersed for 5 minutes with a high-speed stirrer (10,000 rpm).
Dispersing Process III
In 865 ml of water 30 g of gelatin are swollen, dissolved with stirring at a temperature of 50° C. and 10 g of a 10% saponin solution is added. In addition, 10 g of a polyester of Table 1 with a melting point above 70° C., for example, compound no. 1, is dissolved at 50° C. in 85 ml of 4-phenyldioxan. Then, the polyester solution is added slowly to the gelatin solution at 50° C. with stirring with a high-speed stirrer (10,000 rpm) and dispersed for 5 minutes.
The dispersions obtained are solidified by cooling and stored in a refrigerator until use. All of them contain 10 g of a polyester of the invention for 30 g of gelatin. They are very stable and exceptionally compatible with gelatin and other customary components of the casting solution, such as chemical and optical sensitizers or stabilizers or hardening agents or antihalation dyes, and can be added in the desired concentrations to the casting solutions for producing emulsion films and/or protective films and/or back coating films. It is also possible to add the polyester dispersions to antihalation or non-curling films, such as are used on the film back side for the production of films for video amplifying cameras. In a photographic element comprising a polymeric film support, at least one photosensitive layer, and preferably containing one or more additional layers referred to above, the polyester slip agent is contained in the outermost layer on either or both sides of the element.
The polyester dispersions impart outstandng slip properties to the film surface, whereby it is to be emphasized that even small concentrations of the polyester improve the slip very markedly. The desired degree of slip, which can differ from case to case, can be adjusted easily through suitable selection of the slip agent and its concentration. Useful concentrations are located between 0.1 to 50 g per 100 g of gelatin. The optimum setting for each individual application purpose can be determined through simple tests.
The polyester slip agents of the invention, on casting, cause no wetting faults in solutions containing them. Likewise, they do not change the viscosity of the casting solutions. In addition, they are photographically inert and do not affect the sensitometric properties of the films. The photographic materials containing polyesters of the invention are always found to be clear. Delayed development and fixing the irregularities were not observed with them. Also, there are no deleterious effects on the hardening. As an additional advantage, it is to be noted that the slip effect is still present after the films have been processed.
As a particular advantage, the addition of wetting agents to the slip films is recommended, through which the slip properties can be improved further. Particularly suitable are anionic wetting agents, for example,
HOSTAPON® T
C 17 h 33 --co--n(ch 3 ) --ch 2 --ch 2 --so 3 na or
SARKOSYL® NL-97
C 11 h 23 --co--n--(ch 3 ) --ch 2 --coona or
Standapol® es 40
c 14 h 29 o--(ch 2 --ch 2 --o) 2 --ch 2 --ch 2 --o--so 3 na or
NEKAL® BX ##STR5##
These wetting agents can be added in concentrations of up to 5 g per 100 g of binder.
The following examples will illustrate the invention in more detail.
EXAMPLE 1
First, an X-ray film is prepared without a protective coating by coating a polyester film base made of polyethylene glycol terephthalate, which is provided with an adhesion film on both sides, with a conventional silver halide X-ray emulsion on both sides. This X-ray emulsion contains silver bromide with an iodide fraction of 2 weight-% and gelatin in a ratio of gelatin to silver halide of from 0.5 to 1. Besides the emulsion layer contains the customary additives, such as chemical sensitizers, stabilizers, hardeners, wetting agents, etc., which are customarily used for producing and casting X-ray emulsions.
On this emuslion, on both sides, a gelatin protective film is applied by means of a solution having the following composition:
100 g of gelatin
1,350 g of water
35 ml of saponin, 10% aqueous solution
2.5 ml of formalin, 30% aqueous solution
Instead of saponin, other wetting agents also can be used, such as the sodium salt of oleic acid methyltauride (Hostapon® T) or others. Likewise, the formalin may be replaced by other customary hardening agents. The protective film is cast so that, after the drying, it contains 1 g of gelatin per m 2 of film on each side.
In a comparative test A, the protective film solution as above is used without addition of slip agent. In the tests B-K, polyester slip agents according to the invention are used, which were processed according to the dispersing processes I, II or III, depending on the melting point of the additive to the protective film solution. Naturally, the gelatin introduced with the polyester dispersions in the protective film solution is counted in the gelatin given in the composition of the protective film solution. The concentrations used of the polyester slip agents of the invention are evident in Table 2.
Table 2.______________________________________ Conc. of the poly- FrictionPolyester Dispersion ester in g per valueTest from Table 1 Process 100 g of gel %______________________________________A -- -- -- 50B 1 III 30 32C 4 II 0.1 38D 4 II 1 24E 6 III 1 22F 8 II 1 25G 12 II 10 36H 13 I 5 13I 14 III 2 40J 17 I 5 16K 18 I 1 20______________________________________
The friction values given are determined using a procedure analogous to the DIN 53375 of March, 1971, in which the friction between two film samples is measured by measuring the force on a piece of film whose front side rests on the back side of another piece of the same film with a weight on the upper film while the lower film is pulled on a rolling support. The lower the value, the less friction of the film surface.
The sensitometric data and the physical properties of test films B-K containing the indicated slip agents turned out to be unchanged compared with the comparative test A.
EXAMPLE 2
On an X-ray film prepared as in Example 1 without a protective film, a protective film solution having the following composition was again cast:
100 g of gelatin
1,350 g of water
35 ml of saponin, 10% aqueous solution
2.5 ml of formalin, 30% aqueous solution.
Test A contains no slip agent, whereas a polyester dispersion according to the invention was added to the test B. Both tests serve as a comparison against the tests C and E which contain anionic wetting agents in addition.
The compounds used and their concentations are evident in Table 3.
Table 3.__________________________________________________________________________ Polyester Disper- Conc. of poly- Wetting ag- Friction from sion ester in g per ent in g per valueTest Table 1 process 100 g of gel. 100 g of gel. %__________________________________________________________________________A -- -- -- -- 50B 4 II 1 -- 24C 4 II 1 2.5 * 18D 4 II 1 2.5 ** 17E 4 II 1 2.5 *** 16__________________________________________________________________________ * Sodium lauryl sarcosylate (Sarkosyl ** Sodium salt of oleic acid methyltauride (Hostapon *** Sodium myristyl ether sulfate (Standapol ES 40)?
EXAMPLE 3
On an X-ray film without protective film, like that in Example 1, is cast a protective film solution like that given in Example 2. The test A, as in that example, contains no slip agent, whereas in test B, another polyester dispersion according to the invention is added. Again, both tests serve as comparisons against the tests C-F, containing slip agents according to the state of the art.
The compounds used and their concentrations are shown in Table 4.
Table 4.__________________________________________________________________________ Conc. of Fric- Emul- Clear- Slip slip ag- Disper- tion sion ing agent ent g/ sion value mp Turb- timeTest used 100 g gel. process % ° C idity sec__________________________________________________________________________A -- -- -- 50 45 0.05 11B Invention 1 II 25 45 0.05 11 polyester no. 8C Cetyl pal- 1 II 31 36 0.05 14 mitate * mp 54° CD Cetyl pal- 10 II 27 35 0.07 14 mitate * MP 54° CE Dimethyl- 1 *** 39 43 0.06 12 polysil- oxane **F Dimethyl- 5 *** 25 39 0.08 13 polysil- oxane **__________________________________________________________________________ * analogous to German patent ** analogous to German Offenlegungsschrift *** analogous to Example 4 of German Offenlegungsschrift 1,938,959
The tests E and F display very many casting faults as a result of wetting disturbances. As a result they can be evaluated only inaccurately. The emulsion melting points were measured in 2% NaOH. The turbidity is given as optical density with measurement in directed light. The clearing times give the time of disappearance of the turbidity caused by the unexposed silver halide in the course of fixing in a customary acid thiosulfate fixing bath at 27° C.
EXAMPLE 4
A polyester film base made of polyethylene glycol terephthalate, which is provided on both sides with an adhesion film, is coated on the front side with an ortho-sensitized silver halide emulsion for video amplification photographs. On top of this is cast a protective film solution having the basic composition given in Example 2. The back side of this material receives an antihalation backcoat with a coating of 9 g of gelatin/m 2 of film. This antihalation back coat is applied from a solution which, in addition to the usual wetting agents and hardeners, contains the following components:
1,200 g of water
100 g of gelatin
6.5 g of antihalation dye
In Test A, the protective film and the antihalation film were cast as given. On the other hand, the tests B and C in both films contain various quantities of the slip agent dispersions of the invention (compound 4 of Table 1 in combination with the dispersion process II), the concentrations of which are given in Table 5.
Table 5.______________________________________Concentration of the polyesterdispersion in g/100 g gelatinin the pro- Friction value in %tective in the antihala- before pro- after pro-Test film tion backcoat cessing cessing______________________________________A -- -- 32 45B 1 0.1 23 35C 1 1 10 25______________________________________
The processing is carried out at 27° C. in a developer based on hydroquinone/1-phenyl-3-pyrazolidone, which in addition also contains potassium pyrosulfite and potassium hydroxide, and in a fixing bath consisting of ammonium thiosulfate and sodium bisulfite. Subsequently, the film samples are washed at 20° C. and dried at 55° C.
In this example, the friction values are determined between the front and back sides of the film as in Example 1.
However, the polyesters of the invention are not limited to the applications mentioned in the examples. Thus, for example, it is also possible to apply them in organic solvents free of binder. Also, their use is not limited to X-ray films, for example they can also be used to produce motion picture films, color films and other silver halide materials. They can also be combined with other binders or they can be used to produce other light-sensitive materials which contain no silver.
|
Photographic elements with surfaces having improved slip are produced by incorporating in a surface layer a polyester of the formula --O--CO--(CH 2 ) n --CO--O--R-- wherein n = 1-8 and R is selected from certain aliphatic or hydroaromatic groups.
| 6
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BACKGROUND OF THE INVENTION
The present invention generally relates to exercising devices.
There are many exercising devices which are used in special places for public and also by individual users for exercising. It is believed to be advisable to provide a mobile exercising device, which a user can easily use in any place.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide such a mobile exercising device.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in an exercising device which has a belt adapted to be worn by user; and an elastic element fixable by said belt to a user's body and having two ends graspable by a user for expanding said elastic element and exercising.
When the device is designed in accordance with the present invention, it is simple and easy to use by a user in any circumstances. The user simply attaches the device to his body by his belt which he wears, and then he or she can exercise.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing an exercising device in accordance with the present invention; and
FIG. 2 is a side view of a portion of the inventive exercising device.
DESCRIPTION OF PREFERRED EMBODIMENTS
An exercising device in accordance with the present invention has a belt which is identified as a whole with reference numeral 1 . It is formed a conventional belt and can be worn by a user on a waist. The exercising device further has two exercising elements 2 . In the shown embodiment of FIG. 1, each exercising element 2 is formed as a stretchable belt.
In the embodiment of FIGS. 2 a - 2 c the elastic element 2 is composed of a plurality of separate elastic members 2 ′. Each of the elastic members 2 ′ has one end connectable to the belt in the same manner as in the embodiment of FIGS. 1 a - 1 d , and another end provided with a handle 3 . Two elastic members 2 ′ can be used for exercising the user's arms, while two other elastic members 2 ′ can be used for exercising the user's legs.
In the embodiment of FIGS. 3 a and 3 b the elastic members 2 ′ are connected to a joint element formed for example as a plate, which can be of any material, including a soft material, and rubber, fabric, etc. The plate 7 in turn is connected with the belt 1 in the same way as in the preceding embodiments, for example by a bolt and a nut.
In accordance with a further embodiment of the present invention shown in FIGS. 4 a and 4 b , the belt 1 has a buckle 8 so as to adjust the belt. The elastic members 2 ′ are connected with a loop-shaped element 9 , through which the belt 1 can pass. The loop-shaped element 9 can be composed of rubber, fabric, etc.
In the embodiment of FIG. 5 two elastic elements 2 ′ are each provided with handles at opposite ends and:placed under the belt 1 between the belt and the body of a user. Therefore, the elastic elements 2 ′ are firmly held, and the user can stretch the elements by pulling the handles either with his arms or with his legs. An additional intermediate element 10 can be located between the elastic elements 2 ′ and the body and formed as a patch of rubber, fabric and the like. Also, the elastic elements 2 ′ can be formed not as wide elastic band as in the previous embodiment, but as a round rubber cord.
As can be seen from this drawing the device is provided with a braking mechanism which includes an inclined braking pad 4 and a nut 5 screwable into an opening 6 of the handle. When the nut is screwed in the opening the pad is pressed against the: belt and stops its movement. The belt can be adjusted. The pad is somewhat inclined so that the belt can be pulled through the opening to reduce its length but can not move out when the adjustment has been completed.
The elastic elements 2 extend at the right side and left side of an axis of symmetry of the belt and are connected with one another by intermediate portion 19 . A sleeve 20 is wrapped around the portion 19 and its ends can be connected with another by a velcro.
FIGS. 10 a and 10 b shows somewhat different or blocking mechanism. The handle is provided with a conical opening, and a conical wedge-shape member 21 is insertable in the opening. The member 21 is provided with four slots extending from this upper end toward the top and ending shortly before the top so that an upper wall is formed. The belt extends through a central opening of the member 21 with a friction fit. When the belt is pulled by its free end. In FIG. 10 b , it can be easily moved. However, the belt can not be pulled out by its right part since the wedge shape member 21 will move deeper into the opening of the handle, its segments made by the slot compress and firmly hold the member 21 and the belt in the handle.
FIG. 7 shows still a further embodiment. Here the elastic element 11 has a plurality of engaging formations 12 and an opening 13 . The elastic element 1 can be wound so that its part with engaging formations 12 surrounds the belt and passes through the opening 14 so that the engaging formation does not allow the elastic element 1 to unwind and to be disconnected from the belt. The handle series for stretching the elastic element 11 as in the previous embodiment.
As shown in the drawings, the elastic element can be provided with a buckle so that a length of the elastic element can be adjusted.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in exercising device, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
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An exercising device has a belt adapted to be worn by a user, and an elastic element fixable by the belt to a user's body and having two ends graspable by a user for expanding the elastic element and exercising.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present disclosure is part of a continuation-in-part (CIP) application of U.S. patent application Ser. No. 15/444,536, filed 28 Feb. 2017 and currently pending, which is a CIP application of U.S. patent application Ser. No. 15/362,772, filed 28 Nov. 2016 and currently pending, which is a CIP application of U.S. patent application Ser. No. 15/225,748, filed 1 Aug. 2016 and currently pending, which is a CIP application of U.S. patent application Ser. No. 14/818,041, filed 4 Aug. 2015 and issued as U.S. Pat. No. 9,420,663 on 16 Aug. 2016, which is a CIP application of U.S. patent application Ser. No. 14/688,841, filed 16 Apr. 2015 and issued as U.S. Pat. No. 9,288,867 on 15 Mar. 2016, which is a CIP application of U.S. patent application Ser. No. 14/465,174, filed 21 Aug. 2014 and issued as U.S. Pat. No. 9,277,603 on 1 Mar. 2016, which is a CIP application of U.S. patent application Ser. No. 14/135,116, filed 19 Dec. 2013 and issued as U.S. Pat. No. 9,163,818 on 20 Oct. 2015, which is a CIP application of U.S. patent application Ser. No. 13/525,249, filed 15 Jun. 2012 and issued as U.S. Pat. No. 8,749,167 on 10 Jun. 2014. Contents of the above-identified applications are incorporated herein by reference in their entirety.
BACKGROUND
Technical Field
[0002] The present disclosure relates to linear light-emitting diode (LED) lamps and more particularly to a linear LED lamp with electric shock detection and prevention, configured to shut off an accidental LED current to reach ground through a person's body.
Description of the Related Art
[0003] Solid-state lighting from semiconductor light-emitting diodes (LEDs) has received much attention in general lighting applications today. Because of its potential for more energy savings, better environmental protection (no hazardous materials used), higher efficiency, smaller size, and much longer lifetime than conventional incandescent bulbs and fluorescent tubes, the LED-based solid-state lighting will be a mainstream for general lighting in the near future. As LED technologies develop with the drive for energy efficiency and clean technologies worldwide, more families and organizations will adopt LED lighting for their illumination applications. In this trend, the potential safety concerns such as risk of electric shock become especially important and need to be well addressed.
[0004] In today's retrofit application of a linear LED tube (LLT) lamp to replace an existing fluorescent tube, consumers may choose either to adopt a ballast-compatible LLT lamp with an existing ballast used to operate the fluorescent tube or to employ an AC mains-operable LED lamp by removing/bypassing the ballast. Either application has its advantages and disadvantages. In the former case, although the ballast consumes extra power, it is straightforward to replace the fluorescent tube without rewiring, which consumers may have a first impression that it is the best alternative to fluorescent tube lamps. But the fact is that total cost of ownership for this approach is high regardless of very low initial cost. For example, the ballast-compatible LLT lamps work only with particular types of ballasts. If the existing ballast is not compatible with the ballast-compatible LLT lamp, the consumers will have to replace the ballast. Some facilities built long time ago incorporate different types of fixtures, which requires extensive labor for both identifying ballasts and replacing incompatible ones. Moreover, a ballast-compatible LLT lamp can operate longer than the ballast. When an old ballast fails, a new ballast will be needed to replace in order to keep the ballast-compatible LLT lamps working. Maintenance will be complicated, sometimes for lamps and sometimes for ballasts. The incurred cost will preponderate over the initial cost savings by changeover to the ballast-compatible LLT lamps for hundreds of fixtures throughout a facility. When the ballast in a fixture dies, all the ballast-compatible tube lamps in the fixture go out until the ballast is replaced. In addition, replacing a failed ballast requires a certified electrician. The labor costs and long-term maintenance costs will be unacceptable to end users. From energy saving point of view, a ballast constantly draws power, even when the ballast-compatible LLT lamps are dead or not installed. In this sense, any energy saved while using the ballast-compatible LLT lamps becomes meaningless with the constant energy use by the ballast. In the long run, ballast-compatible LLT lamps are more expensive and less efficient than self-sustaining AC mains-operable LLT lamps.
[0005] On the contrary, an AC mains-operable LLT lamp does not require a ballast to operate. Before use of an AC mains-operable LLT lamp, the ballast in a fixture must be removed or bypassed. Removing or bypassing the ballast does not require an electrician and can be replaced by end users. Each AC mains-operable LLT lamp is self-sustaining. If one AC mains-operable tube lamp in a fixture goes out, other lamps in the fixture are not affected. Once installed, the AC mains-operable LLT lamps will only need to be replaced after 50,000 hours. In view of above advantages and disadvantages of both ballast-compatible LLT lamps and AC mains-operable LLT lamps, it seems that market needs a most cost-effective solution by using a universal LLT lamp that can be used with the AC mains and is compatible with an electronic ballast so that LLT lamp users can save an initial cost by changeover to such a universal LLT lamp followed by retrofitting the lamp fixture to be used with the AC mains when the ballast dies.
[0006] In the U.S. patent application Ser. No. 14/688,841, filed Apr. 16, 2015, two shock prevention switches and an all-in-one driving circuit are adopted in an LLT lamp such that AC power from either an electronic ballast or the AC mains can operate the lamp without operational uncertainty and electric shock hazards. In other words, no matter what a lamp fixture is configured as the AC mains or an electronic ballast compatible fashion, the LLT lamp automatically detects configurations and works for either one. All of such LLT lamps, no matter whether AC mains-operable or ballast compatible, are electrically wired as double-ended and have one construction issue related to product safety and needed to be resolved prior to wide field deployment. This kind of LLT lamps, if no shock prevention scheme is adopted in, always fails a safety test, which measures a through-lamp electric shock current. Because an AC-mains voltage applies to both opposite ends of the tube when connected to a power source, the measurement of current leakage from one end to the other consistently results in a substantial current flow, which may present a risk of an electric shock during re-lamping. Due to this potential shock risk to the person who replaces the LLT lamps in an existing fluorescent tube fixture, Underwriters Laboratories (UL) uses its safety standard, UL 935, Risk of Shock During Relamping (Through Lamp), to do a current leakage test and to determine if the LLT lamps meet the consumer safety requirement. Although the LLT lamps used with an electronic ballast can pass the current leakage test, some kinds of electric shock hazards do exist. Experimental results show that the skin of the person who touches an exposed bi-pin may be burned due to such an electric shock. Fortunately, a mechanism of double shock prevention switches used in applications with the AC mains is also effective in applications with the ballasts to prevent the electric shock from occurring, thus protecting consumers from such a hazard, no matter whether input voltage is from the AC mains or the electronic ballast. Therefore, a universal LLT lamp that can work with either the AC mains or the electronic ballast makes sense. The effectiveness of using double shock prevention switches for applications in the AC mains has been well addressed in U.S. Pat. No. 8,147,091, issued on Apr. 3, 2012. However, a conventional shock prevention switch has an inherent issue related to an electric arc when operated with an electronic ballast. Unlike an AC voltage of 120 or 277 V/50-60 Hz from the AC mains, the output AC voltage and current from the electronic ballast presents a negative resistance characteristic. The feature that originally supports a fluorescent tube to function properly becomes extremely detrimental to the conventional shock prevention switch due to the electric arc likely occurring between two electrical contacts that have a high electric potential difference with a high frequency, such as 600 V/50 kHz. Once a consumer fails to follow installation instructions to install or uninstall linear LED tube lamps such that one of two ends of the tube lamp is in the fixture socket connected to a powered electronic ballast, and the other end is tweaked to connect to or disconnect from the associated socket, an internal arcing may occur between the electrical contacts in the associated switch. The arcing even in a short period such as several seconds can generate high heat, burning and melting electrical contacts and neighboring plastic enclosures, creating a fire hazard. The AC voltage of 120 or 277 V/50˜60 Hz from the AC mains does not have such an issue because its voltage is relatively low compared with the ballast output voltage of 600 V. Moreover, the AC frequency of 60 Hz automatically extinguishes an arc every 1/60 seconds, if existed. That is why a utility switch can be used in an electrical appliance to turn power on and off without any problem. However, when used with the electronic ballast, the electrical contacts used in the conventional shock prevention switch can easily be burned out due to the high-voltage and high-frequency arcing introduced between each gap of each pair of the electrical contacts in the conventional shock prevention switch when someone tries to abusively tweak to remove the tube lamp from the fixture with the ballast that has a power on it. Although such a situation is rare, an internal arcing, if occurred, does cause burning and even welding of the electrical contacts and melting of the plastic enclosure, so called internal fire, creating consumer safety issues.
[0007] Today, such LLT lamps are mostly used in a ceiling light fixture with a wall-mount power switch. The ceiling light fixture could be an existing one used with fluorescent tubes but retrofitted for LLT lamps or a specific LLT lamp fixture. The drivers that provide a proper voltage and current to LED arrays could be internal or external ones. Not like LLT lamps with an external driver that is inherently electric-shock free if the driver can pass a dielectric withstand test used in the industry, LLT lamps with an internal driver could have a shock hazard during relamping or maintenance, when the substantial through-lamp electric shock current flows from any one of AC voltage inputs through the internal driver connecting to LED arrays to the earth ground. Despite this disadvantage, LLT lamps with the internal driver still receive wide acceptance because they provide a stand-alone functionality and an easy retrofit for an LLT lamp fixture. As consumerism develops, consumer product safety becomes extremely important. Any products with electric shock hazards and risk of injuries or deaths are absolutely not acceptable for consumers. However, commercially available LLT lamps with internal drivers, single-ended or double-ended, fail to provide effective solutions to the problems of possible electric shock and internal arcing and fire.
[0008] In the prior art mentioned above, the double shock protection switches with mechanical actuation mechanisms protruding outwards from both ends of the LLT lamp are proposed to be used in the LLT lamp. However, a length control of the LLT lamp becomes critical to operate the LLT lamp because sometimes the double shock protection switches may not be actuated by the mechanical actuation mechanisms. Also, the conventional LLT lamp is so vulnerable because it may cause internal fire if consumers abusively tweak the mechanical actuation mechanisms at both ends of the LLT lamp operable with an electronic ballast during relamping. It is therefore the purpose of the present disclosure to disclose an electronic approach to electric shock detection and prevention, to be used in the LLT lamp to eliminate above-mentioned electric shock and internal fire hazards and to work more reliably to protect consumers.
SUMMARY
[0009] A linear light-emitting diode (LED)-based solid-state lamp comprising two lamp bases respectively connected to two ends of a housing, each lamp base comprising at least one electrical conductor connecting to a lamp fixture socket; at least one rectifier; an LED driving circuit; LED arrays; and an electric current flow control module, is used to replace a fluorescent tube or a conventional LED tube lamp without the electric current flow control module in an existing lamp fixture. The LED driving circuit comprises a control loop compensation device that is originally used to precisely control a closed-loop electric current to flow into the LED arrays. The electric current flow control module uses the same control loop compensation device in a way that it detects an electric shock and determines if the LED-based solid-state lamp is operated in a normal mode or in an electric shock hazard mode. When an installer touches an exposed at least one electrical conductor on a lamp base in an electric shock hazard, the electric current flow control module detects such an electric shock hazard and shuts off a return current flow from the LED arrays to reach the at least one rectifier, thus eliminating an overall through-lamp electric shock current.
[0010] The electric current flow control module comprises an electric shock detection module, a timer and power-up control, a logic control module, a switch control device, and at least one switch configured to connect or disconnect the electric current return from the LED arrays. The at least one switch is connected between the LED arrays and the at least one rectifier. When the control loop compensation device sends a control loop correction signal to the electric current flow control module, the electric shock detection module detects if an electric shock occurs. Because an input voltage to the LED driving circuit decreases when such an electric shock occurs whereas the LED driving circuit is designed to provide the LED arrays with a predetermined current over a wide range of the input voltages, a voltage drop due to the electric shock causes a closed-loop current control signal to vary in response to the electric shock. Therefore, the control loop correction signal from the control loop compensation device can be used to detect the electric shock that occurs at an exposed at least one electrical conductor. The electric current flow control module controls the at least one switch to connect or disconnect the electric current flow over the at least one switch, thus turning on or off the power delivering to the LED arrays. The timer and power-up control manages initial timing sequences in the electric current flow control module to enable or disable power to deliver into the electric shock detection module and the logic control module in order to reduce its power consumption and current to meet maximum leakage current requirement. The logic control module in the electric current flow control module manages several electric shock scenarios and maintains the at least one switch in its “on” or “off” state even after power is removed from the timer and power-up control. For instance, once the electric shock is detected when the first bi-pin in LLT lamp is inserted in a socket and the second bi-pin is exposed and touched by an installer, the logic control module maintains the at least one switch in “off” state until the exposed at least one electrical conductor is removed from the installer and normally installed in the lamp fixture socket receiving a normal AC voltage. When the electric shock detection module detects no electric shock, the electric current flow control module controls the at least one switch to continue “on”, thus the electric current being able to continue to flow out from the LED arrays. The scheme can effectively reduce a risk of electric shock hazard to users during relamping or maintenance.
[0011] The LED driving circuit further comprises a Buck control circuit comprising a power factor correction (PFC) and control device, an electronic switch with its on and off controlled by the PFC and control device, an inductor with its current charging and discharging controlled by the electronic switch, and a diode. The control loop compensation device is always connected at a low electric potential side along an LED current path with a low electric potential terminal of the control loop compensation device directly connecting to the at least one rectifier through the at least one switch in the electric current flow control module.
[0012] Although configurations of a Buck control circuit may be different for different designs, the control loop compensation device originally working with the Buck control circuit can effectively provide a control loop correction signal for the electric current flow control module to detect the electric shock and manage to shut off the electric shock current.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Non-limiting and non-exhaustive embodiments of the present disclosure are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified.
[0014] FIG. 1 is an embodiment of an LLT lamp installed in lamp fixture sockets connected with AC power sources according to the present disclosure.
[0015] FIG. 2 is an embodiment of an LED driving circuit configured to work with an electric current flow control module to detect an electric shock according to the present disclosure.
[0016] FIG. 3 is another embodiment of an LED driving circuit configured to work with an electric current flow control module to detect electric shock current according to the present disclosure.
[0017] FIG. 4 is an embodiment of an electric shock detection module and a logic control module configured to work with either an electronic ballast or AC mains.
[0018] FIG. 5 is timing sequences provided by a timer and power-up control.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1 is an embodiment of an LLT lamp installed in lamp fixture sockets connected with alternate current (AC) sources according to the present disclosure. The LLT lamp 500 comprises a housing having two ends; two lamp bases 660 and 760 each having at least one electrical conductor 250 and 350 at each end of the housing; an electric current flow control module 700 ; a pair of electrical contacts 410 and 420 of at least one switch 400 controlled by the electric current flow control module 700 ; at least one rectifier 603 comprising diodes 611 , 612 , 613 , and 614 interconnected at ports 402 , 404 , 503 , and 504 ; an LED driving circuit 100 having a first and a second inputs 503 and 420 ; and LED arrays 214 disposed between the two ends of the housing with the LED arrays 214 connected to the LED driving circuit 100 . The LLT lamp 500 may further comprise an interface module 251 and 351 for each lamp base configured to work with an electronic ballast for maximum compatibility. The interface module may comprise a resistor, a resistor in parallel with capacitor, a jumper, or simply a passing-through connection such as a direct connection between a connection point 401 and the interconnection port 402 for the interface module 251 and a direct connection between a connection point 405 and the interconnection port 404 for the interface module 351 . In the context followed, such direct connections will be used for simplicity unless otherwise specified. Please note that neither of the interface modules 251 and 351 includes a fuse or any EMI (electro-magnetic interference) filters.
[0020] The LED driving circuit 100 comprises a Buck control circuit 101 and a control loop compensation device 120 connected to the Buck control circuit 101 , which is further connected to the LED arrays 214 . When the at least one electrical conductor 250 and the at least one electrical conductor 350 in each lamp base are respectively inserted into the lamp fixture sockets 810 and 820 , the at least one rectifier 603 receives AC power through the at least one electrical conductors 250 and 350 at each end of the housing and converts into a DC (direct current) voltage to supply the LED driving circuit 100 . A normal LED current will flow into the LED arrays 214 and return to the Buck control circuit 101 . The control loop compensation device 120 receives a signal from the Buck control circuit 101 and maintains a voltage signal at a port 109 connecting to electric current flow control module 700 . Because the at least one electrical conductor 250 and the at least one electrical conductor 350 in each lamp base are inserted into the lamp fixture sockets 810 and 820 , the at least one rectifier 603 receives a normal input AC voltage and converts into a DC voltage without a compromise. The Buck control circuit 101 delivers a current equal to a preset value to the LED arrays 214 . In this case, the voltage signal appearing at the port 109 relative to ground represents a voltage value in a normal mode. The electric current flow control module 700 receives the voltage signal appearing at the port 109 , determines that no electric shock occurs, and controls the at least one switch 400 to turn on through a control link 110 such that the electrical contacts 410 and 420 of the at least one switch 400 are electrically connected. Whereas the at least one switch 400 is on, the electric current returned from the LED arrays 214 and the Buck control circuit 101 can flow back to the at least one rectifier 603 to complete a power transfer.
[0021] When either one of the at least one electrical conductor 250 and the at least one electrical conductor 350 in each lamp base is inserted into the lamp fixture sockets 810 or 820 that is connected with “L” of AC mains, the LLT lamp 500 does not light up but is live and energized, meaning that there is an electric shock hazard. If an installer touches the exposed at least one electrical conductor 250 or at least one electrical conductor 350 in each lamp base without the at least one switch 400 in place to control the current returned from the LED arrays 214 , an electric shock current can flow from the LED arrays 214 through the Buck control circuit 101 and the at least one switch 400 to reach the at least one rectifier 603 , further flowing to earth ground through the installer's body, creating an electric shock hazard. However, when such a situation occurs, the at least one rectifier 603 receives a compromised AC voltage according to a divided voltage because a human body is analogous to a 500 ohm-resistor. When a DC voltage provided by the at least one rectifier 603 is not as high as a normal DC voltage, an electric current provided to drive the LED arrays 214 by the Buck control circuit 101 is lower than a preset value, the same as the electric current returned from the LED arrays 214 to the Buck control circuit 101 . The Buck control circuit 101 detects a current decrease and sends a correction signal internally to compensate the current decrease. This forms a closed control loop. The control loop compensation device 120 receives the correction signal from the Buck control circuit 101 and maintains the correction voltage signal at the port 109 . Thus, the electric current flow control module 700 can detect electric shock and control the at least one switch 400 through the control link 110 to turn off an electrical connection between the electrical contacts 410 and 420 of the at least one switch 400 . Thus, the electric shock current is blocked, no substantial leakage current possibly flowing out to the exposed at least one conductor on either lamp base. As can be seen in FIG. 1 , two sockets in each of the external fixture lamp sockets 810 and 820 are shunted, meaning that as long as both the at least one electrical conductor 250 in the lamp base 660 and the at least one electrical conductor 350 in the lamp base 760 connect to the AC power sources, the LLT lamp 500 can get a power to operate. Furthermore, as long as an operating current that operates the electric current flow control module 700 is within a certain limit specified by UL standard 935 , the LLT lamp 500 can be deemed safe for users because a through-lamp electric current is restricted to the operating current of the electric current flow control module 700 rather than a substantial current flow returned from the LED arrays 214 once the electric shock occurs.
[0022] FIG. 2 is an embodiment of an LED driving circuit configured to work with an electric current flow control module to detect an electric shock according to the present disclosure. The at least one rectifier 603 connecting to an AC power source, either the AC mains or an electronic ballast, converts an AC into a DC voltage. The LED driving circuit 100 comprises a Buck control circuit, connecting to the at least one rectifier 603 , comprising an input filter 102 used to filter the input voltage and to suppress EMI noise created in the LED driving circuit 100 , a power factor correction (PFC) and control device 103 , a Buck converter 200 in communicating with the PFC and control device 103 , a switch 201 controlled by the PFC and control device 103 , an output capacitor 105 in parallel with a resistor 106 connected to the Buck converter 200 to build up an output voltage and to power the LED arrays 214 , a current sensing device 107 , and a voltage feedback module 300 extracting partial energy from the output voltage to sustain the PFC and control device 103 . The at least one rectifier 603 has four input/output ports, among which a high electric potential appears at the input/output port 503 , and a low electric potential appears at the input/output port 504 respectively connecting to the high side and the low side of the input filter 102 with the low electric potential port 504 as a common ground. The LED driving circuit 100 further comprises a control loop compensation device 120 . The control loop compensation device 120 receives a control loop correction signal from the PFC and control device 103 and maintains the control loop correction voltage signal at a port 109 as an input to the electric current flow control module 700 . Thus, the electric current flow control module 700 can detect electric shock and control the at least one switch 400 through the control link 110 to turn off an electrical connection between the electrical contacts 410 and 420 of the at least one switch 400 .
[0023] In FIG. 2 , when the power is on, an input current enters the input filter 102 and then the PFC and control device 103 , turning on the switch 201 . Whereas the diode 202 is reverse-biased, the input current goes from the resistor 106 and the LED arrays 214 , a primary winding of the transformer 206 , the switch 201 , and the current sensing device 107 to the common ground 504 . The primary winding of the transformer 206 serves as an inductor. When the input current goes into the primary winding of the transformer 206 , energy is stored in it. The PFC and control device 103 detects the input voltage level and control the switch 201 on and off in a way that a desired or otherwise predetermined output voltage V o across the LED arrays 214 is reached to light up the LED arrays 214 . When the switch 201 is off, the diode 202 is forward-biased, and the primary winding of the transformer 206 releases the energy stored, resulting in a loop current flowing from the diode 202 and the LED arrays 214 , back to the primary winding of the transformer 206 , completing the energy transfer to the LED arrays 214 . When the switch 201 is on, the input current flows into the LED arrays 214 , the primary winding of the transformer 206 , the switch 201 , and the current sensing device 107 , creating a voltage drop across the current sensing device 107 . The voltage appearing at the port 204 of the current sensing device 107 inputs to the PFC and control device 103 to control the off-time of the switch 201 . The voltage feedback module 300 has two connection ports 301 and 302 , with the first connection port 301 connecting to a high side of a secondary winding 207 in the transformer 206 and with the second connection port 302 connecting to the PFC and control device 103 . The voltage feedback module 300 continuously monitors the output voltage by using the secondary winding 207 in the transformer 206 . When the voltage at the high side of the secondary winding 207 is higher than a becoming lower operating voltage in the PFC and control device 103 due to increased internal operations, the diode (not shown) in the voltage feedback module 300 conducts to supply energy in time through the second connection port 302 to sustain the operating voltage in the PFC and control device 103 . In brief, as long as the PFC and control device 103 continues to receive power and to maintain its operation, the switch 201 is controlled to turn on and off such that the electric current continues to pump into and out of the LED arrays with a preset value.
[0024] In FIG. 2 , the LED driving circuit 100 is further connected to the electric current flow control module 700 via the port 109 with the control loop correction voltage signal directly entering the electric current flow control module 700 . The electric current flow control module 700 comprises an electric shock detection module 505 , a logic control module 506 , a timer and power-up control 507 , a switch control device 508 , and at least one switch 400 configured to connect or disconnect the electric current return from the LED arrays 214 . The electric shock detection module 505 receives the control loop correction voltage signal from the port 109 connecting to the control loop compensation device 120 . The control loop correction voltage signal from the port 109 represents a closed loop control signal to control the current flowing into and out of the LED arrays 214 to the preset value mentioned above. When an electric shock occurs, the supplied DC voltage from the at least one rectifier 603 drops, the control loop correction voltage signal from the control loop compensation device 120 tends to increase to compensate the voltage drop in order to maintain the current flowing into and out of the LED arrays 214 to the preset value. The electric shock detection module 505 compares the control loop correction voltage signal with reference voltages associated with different input voltages, determines if the electric shock occurs, and converts an analog voltage signal into a bilevel signal to send to the logic control module 506 via a data bus 511 , subsequently controlling the switch control device 508 to control the at least one switch 400 to switch on when an electric shock is not detected or to switch off when an electric shock is detected. The reference voltages are preset as an optimum threshold to minimize an error probability of the through-lamp electric shock detection. The timer and power-up control 507 dictates the switch control device 508 to turn on the at least one switch 400 only for a short power-up period after the power is on no matter whether an input voltage is normal or compromised due to the electric shock. After the short power-up period, the logic control module 506 takes over the control of the switch control device 508 to turn the at least one switch 400 on or off based on the bilevel signal received. The logic control module 506 comprises one or more one-bit memory to latch the at least one switch 400 in a way that the at least one switch 400 will remain “on” if the electric shock is not detected and remain off if the electric shock is detected in the short power-up period. This function ensures that the LLT lamp can operate more reliably without flickering when an input voltage accidentally becomes lower than a normal line voltage due to possible power grid fluctuations for a long run. In FIG. 2 , the electric current flow control module further comprises a detection and timing signal data bus 509 between the timer and power-up control 507 and the electric shock detection module 505 and a timing signal data bus 510 between the timer and power-up control 507 and the logic control module 506 . Details of timing sequences will be discussed in FIG. 4 and FIG. 5 .
[0025] FIG. 3 is another embodiment of an LED driving circuit configured to work with an electric current flow control module to detect electric shock according to the present disclosure. FIG. 3 has all the components as in FIG. 2 , except that interconnections are different, that the control loop compensation device 120 is connected with the at least one switch 400 at the electrical contact 410 in the at least one switch 400 , and that a center-tapped inductor 203 in FIG. 3 replaces the transformer 206 in FIG. 2 . In FIG. 3 , the same numerals are used for the same components as in FIG. 2 . In FIG. 3 , the Buck converter 200 comprises a switch 201 controlled by the PFC and control device 103 , a diode 202 , and an inductor 203 with its current charging and discharging controlled by the switch 201 . The PFC and control device 103 detects zero current in the inductor 203 within an AC cycle of an input voltage generating a zero-current detection signal and controls the switch 201 on and off with a constant on-time and a varied off-time controlled by the zero-current detection signal. By adapting switching frequencies for a high frequency associated with a ballast and a low frequency associated with the AC mains, the PFC and control device 103 controls the switch 201 on and off in a way that the inductor 203 is charged during on-time and discharged during off-time, and that a desired or otherwise predetermined output voltage V o across the LED arrays 214 is reached to light up the LED arrays 214 . The average inductor current is thus equal to the output current that flows into the LED array 214 . When the switch 201 is on, the diode 202 is reverse-biased, and an input current flows from an output port 108 in the input filter 102 , the switch 201 , the first port 204 of the current sensing device 107 , the current sensing device 107 itself, and the second port 205 of the current sensing device 107 , into the inductor 203 . When the current flowing into the inductor 203 increases, the voltage across the current sensing device 107 increases. The first port 204 of the current sensing device 107 also connects with the PFC and control device 103 , which continuously receives signals and adjusts the off-time such that the output voltage and current to the LED arrays 214 are regulated to meet the output requirements. The output capacitor 105 in parallel with the resistor 106 connects to the inductor 203 , receiving energy to build up an output voltage and to power the LED arrays 214 .
[0026] The inductor 203 configured as an autotransformer has a center-tapped port connecting to the voltage feedback module 300 comprising a diode. The voltage feedback module 300 has two connection ports 301 and 302 , with the first connection port 301 connecting to the center-tapped port of center-tapped inductor 203 and with the second connection port 302 connecting to the PFC and control device 103 . The PFC and control device 103 has an input capacitor (not shown) with a voltage built up to supply an internal logic control circuit (not shown) in the PFC and control device 103 . When the voltage decreases due to its increased internal operations and controls, and when the voltage at the center-tapped port of the inductor 203 is higher than the supplying voltage, the diode in the voltage feedback module 300 conducts to supply a current to the PFC and control device 103 and sustain its operations. The function of the voltage feedback module 300 is essential because the LED driving circuit 100 has a wide range of operating voltages not only 110 and 277 VAC for AC mains but also 350˜600 VAC for an electronic ballast. In the PFC and control device 103 , a start-up resistor (not shown) is so designed to operate a LLT lamp at the lowest input voltage 110 VAC. When the highest voltage 600 VAC from the electronic ballast comes in, a higher proportional voltage appears at an input of the internal logic control circuit. Therefore, an operating voltage for the internal logic control circuit must be in a wide range such as 11˜35 VDC rather than 5˜15 VDC as in a conventional logic control device. To meet requirements of start-up time and current without turn-on failure or flickering occurred at the lamp start-up, the input capacitor in the PFC and control device 103 with a minimum capacitance is designed and used at the input of the internal logic control circuit. The voltage feedback module 300 is thus needed to pump in energy in time and to sustain the operating voltage and ensure no flickering occurred when operating the LLT lamp.
[0027] When the switch 201 is off, the diode 202 is forward-biased, and the inductor 203 discharges with a loop current flowing from the LED arrays 214 , the diode 202 , the current sensing resistor 107 , back to the inductor 203 . The current sensing resistor 107 keeps track of the output current and feedbacks to the PFC and control device 103 to further control the switch 201 on and off. The closed loop operation in both on-time and off-time of the switch 201 ensures the output current to be accurately controlled within 4%.
[0028] In FIG. 3 , the LED driving circuit 100 is also connected to the electric current flow control module 700 for electric shock detection as in FIG. 2 . Same as in FIG. 2 , the electric shock detection module 505 in the electric current flow control module 700 receives the control loop correction voltage signal from the control loop compensation device 120 and detects for a short period after the power is on to see if the electric shock occurs. No matter whether the electric shock is detected or not, a bilevel voltage signal is generated by the electric shock detection module 505 and sent to the logic control module 508 to process. The logic control module 508 manages several scenarios, integrates results from the several scenarios, and sends a signal to the switch control, subsequently controlling the at least one switch 400 to turn “on” or “off”. If the electric shock is detected, the at least one switch 400 is turned “off”, thus blocking the electric shock current to flow to the earth ground through the installer's body. On the other hand, if the electric shock is not detected for a short power-up period after the power is on, the electric current flow control module 700 controls the at least one switch 400 to turn on and continue on, thus allowing the current return from the LED arrays 214 to reach the earth ground and completing an energy transfer to the LED arrays 214 for lighting.
[0029] FIG. 4 is an embodiment of an electric current flow control module configured to work with either an electronic ballast or AC mains. Same as in FIGS. 2-3 , the electric current flow control module 700 comprises an electric shock detection module 505 , a logic control module 506 , a timer and power-up control 507 , and a switch control device 508 . The electric shock detection module 505 comprises a high frequency detection module 803 configured to detect if the high frequency voltage from the electronic ballast is present and a comparator module 804 configured to determine if the electric shock occurs when a line voltage from AC mains is present. In FIG. 1 , when the at least one electrical conductor 250 and the at least one electrical conductor 350 in each lamp base of the LLT lamp 500 are inserted into the lamp fixture sockets 810 and 820 , the LLT lamp 500 must first determine if the power is from an electronic ballast or AC mains because there is no concern of electric shock when the LLT lamp 500 operates with the electronic ballast. The AC voltages from the electronic ballast and the AC mains differ significantly in frequency, for instance, 25 kHz and above for the electronic ballast versus 60 Hz for the AC mains. After the AC voltages are rectified by the rectifier 603 (in FIGS. 1-3 ), the ripples in the DC voltages show a frequency doubled. The frequency difference between the DC voltages rectified from the AC voltages provided by the electronic ballast and the AC mains can be used to detect if the high frequency voltage from the electronic ballast is present. In FIG. 4 , if high frequency ripples are detected from the DC voltage rectified, the logic control module 506 dictates a high-level voltage to appear at the switch control device 508 , subsequently controlling the at least one switch 400 to turn “on” and to remain “on”. On the other hand, if the high frequency ripples are not detected from the DC voltage rectified, the comparator module 804 compares the control loop correction voltage signal appeared at the port 109 from the control loop compensation device 120 and converts the control loop correction voltage signal into a bilevel voltage signal and sent to the logic control module 508 to process. Four scenarios for line voltage operation from the AC mains include 120 VAC-normal, 120 VAC-electric shock, 277 VAC-normal, and 277 VAC-electric shock. Therefore, the comparator module 804 may comprise one or more comparators to precisely detect electric shock over a wide range of input AC voltages. The logic control module 506 manages to integrate these four scenarios and the high frequency scenario into one result, a high-level or a low-level voltage to the switch control device 508 to turn “on” or “off” the at least one switch 400 . In this case, the logic control module 506 may further comprise one or more logic gates such as Not gates (inverters), AND gates, and OR gates coupled between the one or more comparators and the one or more one-bit memory devices and between the one or more one-bit memory devices and the switch control device 508 .
[0030] FIG. 5 is timing sequences provided by a timer and power-up control to control the high frequency detection module 803 , the comparator module 804 , and the logic control module 506 . Referring to FIG. 4 and FIG. 5 , the electric shock detection module 505 comprises two detection ports—“a” and “b” and two timing ports—“c” and “d”, whereas the logic control module 506 comprises one data bus 511 and one timing bus comprising two timing ports—“e” and “f”. The ports “b”, “c”, and “d” receive data from a bus 509 in FIGS. 2-3 . The detection port “a” is connected between the control loop compensation device 120 and the comparator module 804 for the comparator module 804 to detect an electric shock. Whereas the detection port “b” receives a DC voltage with ripples to be detected, the timing signal on the port “c” is sent to and enables the high frequency detection module 803 to detect a ripple frequency and determine if the electronic ballast is present. In FIG. 5 , the timing signal on the port “c” starts at t=0 and stops at t=T 1 .
[0031] The timing signal on the port “d” is sent to the comparator module 804 to detect if the electric shock occurs. Outcomes of the high frequency detection and the through-lamp electric shock detection are sent to the logic control module 506 via the data bus 511 in FIGS. 2-4 . The timing signal on the port “d” starts at t=T 2 and stops at t=T 3 . The two timing ports—“e” and “f” receive timing information from the timer and power-up control module 507 via the timing bus 510 . In FIG. 5 , timing sequence on the port “f” is sent to the one or more one-bit memory used to store a status of the outcomes from the high frequency detection and the through-lamp electric shock detection. The one or more one-bit memory receives a high-level voltage at all time starting as soon as the LLT lamp 500 receives the power (t=0). The port “e” receives a high-level voltage to enable the switch control device 508 for a short power-up period from t=0 to t=T 3 so that an LED driving current can flow into and out of the LED arrays 214 , and the control loop correction voltage signal from the control loop compensation device 120 can be sent to the electric shock detection module 505 to determine if the electric shock occurs. After the detection (t>T 3 ), the port “e” receives a low-level voltage, and the status (a high- or a low-level voltage) on the one or more one-bit memory determines if the switch control device 508 receives the high- or the low-level voltage. That is to say, the timer and power-up control 507 is configured to respectively turn on and off power supplied to the at least one switch 400 , the high frequency detection module 803 , and one or more comparators 804 in a predetermined timing manner such as T 3 >T 2 >T 1 >0 whereas T 3 is less than several milliseconds.
[0032] In FIGS. 1-3 , the electrical contacts 410 and 420 of the at least one switch 400 may be an electrical, an electronic, an electro-mechanical, or a mechanical switch such as one in a solid-state relay, an electronic relay, an electro-mechanical relay, a pair of mechanical contacts, or other bidirectional and unidirectional current control devices such as a triac, a back-to-back thyristor, a silicon-controlled rectifier (SCR), a transistor, a metal-oxide-semiconductor field-effect transistor (MOSFET), a field-effect transistor (FET), a transistor, or various combinations thereof. Also, such devices may be connected with some snubber circuits to maintain their functionality under voltage spikes. Please note that although the LED arrays 214 are used throughout the context, the LED arrays may mean one or more LED arrays. The control loop compensation device 120 in FIGS. 1-3 may comprise a capacitor or a capacitor in series with a resistor.
[0033] Whereas preferred embodiments of the present disclosure have been shown and described, it will be realized that alterations, modifications, and improvements may be made thereto without departing from the scope of the following claims. Another kind of the through-lamp electric shock prevention schemes in an LED-based lamp using various kinds of combinations to accomplish the same or different objectives could be easily adapted for use from the present disclosure. Accordingly, the foregoing descriptions and attached drawings are by way of example only, and are not intended to be limiting.
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A linear light-emitting diode (LED)-based solid-state lamp comprises an LED driving circuit, LED arrays, at least one rectifier, and an electric current flow control module. The LED driving circuit comprises a control loop compensation device with a control loop correction signal to precisely control an electric current to flow into the LED arrays. The electric current flow control module uses the control loop correction signal in a way that it detects and determines if the linear LED-based solid-state lamp is operated in a normal mode or in an electric shock hazard mode. When an electric shock hazard is identified, the electric current flow control module shuts off a return current flow from the LED arrays to reach the at least one rectifier, thus eliminating an overall through-lamp electric shock current. The scheme can effectively prevent a through-lamp electric shock from occurring during relamping or maintenance.
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BACKGROUND OF THE INVENTION
This invention relates to the driving of earth anchors into the earth, and in particular to an improved method and drive tool for driving medium duty earth anchors. Medium duty earth anchors have a number of uses in supporting and stabilizing static structures. Probably their most common use today is in anchoring mobile homes, although they are also used for anchoring or guying a wide variety of other structures.
A "medium duty earth anchor" includes a guy rod having a diameter of from about one-half to about three quarters inch and a length of from 3 to 5 feet, and a single turn helix, having a diameter from about 4 to about 8 inches, near the lower end of the rod.
The rod is typically made of carbon steel (0.20% to 0.40% carbon: SAE 1020 to 1040). The lower end of the rod is generally pointed and the head of the rod is provided with some sort of attachment means for attaching the anchor to a guy wire, strap or the like. The attachment means may be an eye or buckle or may simply be a screw thread or the like to which a fastener may be attached.
The helix is conventionally a sheet metal disc about one-eighth to three-sixteenths inches thick, having a radial split and being bent to form a single turn screw thread. The pitch of the helix, that is, the axial distance between the edges of the radial split, is from about 1 to 3 inches. The pitch of a 6 inch helix is typically about 13/4 inches at the guy rod and 2 inches at the circumference of the disc. The helix is typically spaced about 2 inches from the sharpened lower end of the guy rod. Some anchors include a second helix spaced perhaps 41/2 inches above the lower helix. The configuration of the helix may vary somewhat from that described, and is not critical to the present invention.
Medium duty anchors are well known and are commercially available from numerous manufacturers.
The installation of medium duty earth anchors has proven difficult. The anchors are too large for easy installation with a hand-held lever bar. The large, truck-mounted drilling equipment used for driving heavy-duty utility anchors, however, is also impractical; many jobs simply do not require installation of enough anchors to justify bringing in large equipment, and the space available frequently precludes its use.
In recent years hand-held electric drive tools have been used for driving medium-duty anchors. For the most part, these tools have been pipe threaders equipped with special adapters for driving earth anchors. These drivers include the usual horizontal handle and horizontal universal (AC-DC) motor. The motor drives a worm which in turn drives a ring gear. As is well known, the universal motor has a high shaft speed, 3500 rpm or more, which is reduced by the gearing to a ring gear speed of from about 14 to 26 rpm. The motor may be from about 1/2 to 1 horsepower. A slip-through adapter in the ring gear converts the pipe threader to an anchor driver. The adapter may engage the head of the anchor or may be of the type which extends the length of the anchor rod and drives the upper edge of the disc itself. The adaptation of the pipe threader may also include the addition of a second handle, for two-man operation.
Although such electric drive tools are in general use today, they are a far from satisfactory approach to driving medium duty anchors. The anchor frequently strikes obstructions in the ground, such as rocks and roots, and often hangs up on them. When it does, the shock throws the operators off balance and sometimes causes them injuries. When the anchor hangs up, it must be backed out a way and driven again, in hopes of missing the obstruction. Many times, the anchor must be extracted and started anew, or a new anchor used if the first is bent beyond use. Although anchors driven by prior anchor driving means occasionally cut through obstructions on which they hang up, this is not always advantageous as when the obstruction is a buried pipe or electrical cable.
Another problem with previously known electric anchor drivers has been their extremely short life. The gears are stripped or the motor is burned out with discouraging regularity.
A number of governmental agencies have specified minimum holding power for mobile home anchors. The specifications have not always been met with prior driving tools when the soil has provided less than perfect holding qualities.
SUMMARY OF THE INVENTION
One of the objects of this invention is to provide a method and drive tool for driving medium duty earth anchors in such a way as to provide greater holding power than has heretofore been obtainable.
Another object is to provide such a method and driver which greatly reduce the anchor's tendency to hang up on obstructions.
Another object is to provide such a method and driver which cause far less strain on driver and operator.
Another object is to provide such a method and driver which will generally insert anchors in as little time as with prior means, often in less.
Yet another object is to provide a simple, rugged, and long-lived driver.
Other objects will become apparent to those skilled in the art in light of the following description and accompanying drawings.
In accordance with this invention, generally stated, a method of driving a medium duty anchor is provided which comprises engaging the head of the anchor with an electric motor-powered drive tool at a distance of at least 2 feet from the helix of the anchor and driving the anchor at a speed no more than 10 rpm, preferably about 6 rpm. The preferred drive tool includes a small induction motor, preferably about one quarter horsepower, a gear train made up entirely of spur and helical gears, the output shaft of the gear train being parallel to the shaft of the motor, and engagement means for engaging the head of the anchor, the engagement means preferably including a pair of socket parts forming a limitedly flexible coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, FIG. 1 is a view in perspective of the preferred embodiment of anchor driver of this invention, connected to a typical medium duty earth anchor for use in the method of the invention;
FIG. 2 is a view in perspective of the driver of FIG. 1, shown inverted and with its anchor-engaging socket removed;
FIG. 3 is a view in elevation of a typical medium duty anchor; and
FIG. 4 is a sectional view of the gear box and socket to show the gears more clearly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, reference numeral 1 indicates one illustrative embodiment of earth anchor driver of this invention, for use in a method of driving a medium duty anchor such as the anchor designated by the numeral 3.
The driver 1 includes an induction motor 5, a gear box 7, a support bracket 9, handle means 11, and engagement means 13 for holding the head of the anchor 3.
The motor 5 is a quarter horsepower split phase motor having a rated (full load) speed of 1725 revolutions per minute. It draws about 4.6 amps at rated load and 120 volts. The motor is easily reversible by reversing the leads of the main or aux windings through a simple reversing switch, and it provides full power in either direction of rotation. Its speed-torque curve is typical of induction motors, reaching maximum torque of about 230% full load torque at about 75% synchronous speed.
The gear box 7 is secured to the motor 5, and as shown in FIG. 4, the upper part 15 of the box 7 may be cast integral with the lower end shield of the motor 5. The step-down gear train 16 within the gear box 7 includes a helical gear 17 cut in the rotor shaft 19 of the motor 5 and a mating helical gear 21. The remainder of the gears 23, 25, 27 and 29 are spur gears. The shafts 31, 33 and 35 of the gear train are all parallel with the rotor shaft 19 and are journaled in the upper casing part 15 and in a lower cover part 37. The cover plate 37 is secured to the upper casing part 15 by screws 38. The gear train 16 provides a speed reduction of 288:1, or a speed of output shaft 35 of 6 rpm at the rated speed of 1725 rpm of the motor shaft 19.
The support bracket 9 is in the form of a four sided box having a top wall 39, a front wall 41, and side walls 43. The free edge of the top wall 39 is cut away in a semi-circle 45 to fit the vertical cylindrical casing of the motor 5, and the front wall 41 is bolted to the gear box 7 by tapped bolts 46.
The handle means 11 include a pair of handles 47 welded to the upper wall 39 of the bracket 9 and a stabilizing bar 49 welded at its ends to the handles 47. Handle extensions 51 extend the total length of the handle means to 5 feet. The handle extensions 51 slip fit into the ends of the handles 47.
A junction box 53 is mounted between stabilizing bar 49 and one of the handles 47. Electric cord 55 is connected through an on-off spring-loaded toggle switch 57 and through a forward-reverse selector switch to the motor 5. The switches are mounted on opposite ends of the junction box 53.
The engagement means 13 include an adapter 59 secured to the lower end 61 of the output shaft 35 by a Woodruff key 62. The lower end of the adapter is a square shank 63. The engagement means 13 also include a socket 65, the upper end of which is provided with a square socket part 67, for receiving the end of the shank 63. The depth of the square socket part 67 is chosen to allow about one-eighth of an inch space between the adapter 59 and the socket 65, thereby allowing a very small amount of play between the two parts of the engagement means. The lower end of the socket 65 is provided with a hexagonal socket part 69 and a circular bore 71 for receiving the head of the illustrative anchor 3 as hereinafter described.
The anchor 3 is typical of the type of medium duty anchor for which the present invention is particularly adapted. It includes a guy rod 73 made of SAE 1040 steel and having a length of 54 inches and a diameter of eleven-sixteenths inch. The head 75 of the rod 73 is threaded to receive a strap head or other fastener, and at the lower end of the threads, about 6 inches from the top of the rod, a hex nut 77 is welded to the rod 73. The lower end 79 of the rod is sharpened and acts as a leader and guide for the anchor. A helix 81 is welded to the rod 73 about 21/2 inches from the lower end of the rod. The helix has a diameter of 6 inches and a pitch of about 2 inches at its circumference, about one quarter of an inch less at the rod.
The method of driving anchors with the driver of this invention requires simply that the head 75 of the rod be inserted in the socket 65 with the hex nut 77 snugly engaged by the hexagonal socket part 69 and the threaded head of the rod extending into the bore 71. Two men then lift the combined driver and anchor into a position to drive the anchor at the desired angle, each man holding one of the handles 47 or extensions 51. The angle at which the rod is held will generally be nearly vertical, although a more oblique angle may sometimes be necessary, as when the anchor must be angled under a cement slab. One operator then presses the toggle switch 57 to start the driver 1 and drive the anchor 3 into the earth.
It has been found that the seemingly impractical low rotational speed of this invention actually produces none of the expected drawbacks and provides a number of unexpected advantages.
At a speed of 6 rpm, the anchor helix bites into the soil cleanly and disturbs the soil less than with prior methods. In fact, the anchor draws itself into the earth a distance virtually equal to the full pitch of the helix for each revolution of the anchor. Thus, the anchor is driven a full 48 inches into the earth in about four minutes. By comparison, at the 26 rpm speed of a prior art device, the anchor is inserted only about 11/2 inches per revolution. Therefore, in an ideal soil which contained no obstructions and which offered so little resistance to the anchors that the universal motor of the prior art device ran at substantially synchronous speed, the prior art device would insert an anchor about 23/4 minutes faster than the drive tool 1. In the overall job of anchoring mobile homes this time difference is not particularly significant. Such soil is extremely rare.
In the more usually encountered soils, the driver 1 inserts anchors faster than prior art devices, and the worse the soil the more marked is the improvement. This increased speed in practical operation is directly attributable to the decreased speed of the drive tool, as well as to the type of motor and gear train utilized. At the reduced speed of the present method, the chances of striking an obstruction are reduced because the helix cuts through an area equal to little more than its thickness (about 3/16 inch). Striking an obstruction is also less likely to slow the insertion job. Because of its gearing and the speed-torque characteristics of a split phase induction motor, the quarter horsepower motor 5 provides sufficient torque to twist the anchor rod 73 beyond its elastic limit (about 350 ft. lbs.) without substantially slowing its rate of rotation, should the anchor helix strike an obstruction. A 3/4 horsepower universal motor geared to a rated speed of 26 rpm must slow nearly to half speed to provide this torque. More importantly, it has been found that at 6 rpm the helix does not usually bite into the obstructions it strikes, but instead works around them as the anchor rod is twisted and bent above it. Therefore, the anchor is usually inserted in a single operation without the frequent stoppages for backing out the anchor which have previously characterized driving medium-duty anchors.
At the low speed of the present invention, no substantial shock load is transmitted through the anchor rod when the anchor strikes an obstruction. Instead, the head of the rod continues to turn and the load is stored in the rod as a generally uniform torsional stress. The split phase motor 5 exerts its maximum torque at about 1350 rpm. If the rod does not shear when the motor slows to that speed, the motor stalls and its rotation is automatically reversed by the unwinding of the torsion rod to which it is attached. In fact, if the spring-loaded toggle switch 57 is not released when the motor 5 stalls, the motor 5 will continue to rotate in reverse and will back the anchor out because the gear train operates equally efficiently in either direction. Therefore, unlike a universal motor, which exerts maximum torque at stall, the induction motor 5 is protected against burn out.
The quarter horsepower induction motor 5 does not draw excessive current or overheat even when it is on the hundred foot extension cord commonly required on anchor driving jobs. Therefore, even though the motor 5 is substantially undersized compared with the universal motors of prior anchor drivers and even though single phase induction motors (particularly split phase motors) are noted for being inappropriate for high inertia loads, the motor 5 has proven superior to those of the prior art devices.
The vertical split phase motor 5 and the gear train 16 of helical and spur gears (gear wheels) provide full power in either the forward or the reverse setting of the selector switch. They also provide a better balanced tool than prior drivers.
One of the most important advantages of the lower speed is that it increases the holding power of the installed anchor. Even in the best soil (fibrous, black soil), an anchor inserted in accordance with the present invention at 6 rpm with the driver 1 has been found to have about 500 pounds more holding power than a similar anchor inserted at 26 rpm with a prior art driver. In more typical soil the relative holding power is even greater because the anchor has been backed out and reinserted far less, hence the soil has been disturbed far less.
Numerous variations, within the scope of the appended claims, will be apparent to those skilled in the art in light of the foregoing description. For example, although a drive speed of 6 rpm is preferred, speeds up to about ten rpm are usable and provide many of the advantages of the present invention, although the advantages are less pronounced as the speed increases. About 10 rpm a larger motor is required to provide adequate torque, the tendency of the anchor to hang up shows a marked increase, and the shock load transmitted through the rod when the anchor hits an obstruction becomes objectionable. Lower speeds are also useable, although they are not believed to provide substantial advantages over the preferred speed and do increase the time consumed in driving the anchors. As previously mentioned, the driver 1 may be used with other anchors than the illustrative anchor 3, the only modification usually necessary being replacement of socket 65 with a part adapted to engage the head of the other anchor. These variations are merely illustrative.
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A medium duty earth anchor of the type having one or two single turn helixes near the lower end of a rod is driven into the earth by means of a hand-held drive tool having a vertical quarter horsepower split phase motor, a step-down gear train which reduces the drive speed to 6 r.p.m., and a vertical socket which drivingly engages the head of the rod.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to sewing machine attachments providing for the formation of loose loops of thread in zig-zag stitches.
2. Description of the Prior Art
It becomes desirable at times to be able to form loose loops of thread in zig-zag stiches on a sewing machine, as for example, when a pattern is to be tacked to layers of fabric with stitches which subsequently are to be cut and removed, or when a decorative fringe such as may be formed from severed loops of thread is needed to finish off the edges of a table scarf, linen placemat, napkin or the like. Sewing machine attachments which include a fixed support over which zig-zag stitches may be formed to provide loose loops of thread are well known. However, such attachments have suffered from a disadvantage in that the height of the fixed support and therefore the length of the loops which could be formed thereon was limited to an undesirable extent by the need to avoid interference of the support with the sewing needle of the machine as it descended during the formation of zig-zag stitches.
SUMMARY OF THE INVENTION
In accordance with the invention a loop forming sewing machine attachment is provided with an elongated member to support the loops of zig-zag stitches and move from an elevated to a depressed position during downward movement of a needle bar to avoid having the supporting member interfere with the needle of the machine. The device includes a shank adapted for attachment to a presser bar and a sole plate with a needle accommodating opening permitting the formation by a sewing needle of zig-zag stitches in fabric under the sole plate. The movable elongated member operably associates with the needle bar for movement therewith in a downward direction from its elevated position during downward movement of the needle bar, and return means cause the member to resume its elevated position as the needle bar rises.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the loop forming attachment of the invention in use on a sewing machine illustrated in the phase of its operating cycle wherein the sewing needle is descending on one side of the loop supporting member of the attachment;
FIG. 2 is a view similar to FIG. 1, but with the machine at that phase of its operating cycle wherein the needle is at the bottom of its stroke on the other side of the loop supporting member;
FIG. 3 is a front elevational view, showing the attachment partially in section and showing the sewing machine needle at the bottom of its stroke;
FIG. 4 is a front end view of the attachment; and
FIG. 5 is a longitudinal vertical sectional view of the attachment taken substantially on the plane of the line 5--5 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, reference character 10, designates a head end portion of a lockstitch zig-zag sewing machine including a work supporting bed 12. The head end portion 10 carries a reciprocable needle bar 14 and a presser bar 16. A loop forming attachment 18 according to the invention is shown affixed to a flattened lower end portion 20 of the presser bar 16 with a thumb screw 22.
Attachment 18 includes an upstanding shank 24, a sole plate 26, a side bracket 28, an elongated loop supporting member 30, and a pivoted member 32 to which the loop supporting member 30 is secured. The shank 24, sole plate 26 and side bracket 28 are preferably formed as a single piece of plastic material.
As shown, the sole plate 26 has upturned end toes 34 and 36, and a needle accommodating aperture 38 of sufficient width to permit a needle 40, secured with a thumb screw 42 in a needle clamp 44 on the needle bar 14, to sew layers 46 and 48 of material under the sole plate with zig-zag stitches. The needle accommodating aperture 38 extends through the shank 24 as indicated.
Elongated member 30 is a length of bent wire which is held is a fixed position relative to member 32 by a collar 50 formed on a side 52 of the member 32 and by an end projection 54 on the member 30 overlapping the top edge 56 of member 32. Member 30 extends for the greater portion of its length in a forward and rear direction on the machine, that is in the direction in which work is moved by a feed dog (not shown) under material to be sewn, and in alignment with a longitudinally extending center-line for needle aperture 38.
Member 32 is mounted with a screw 58 for pivotal movement on side bracket 28 about an axis 60. As shown the screw 58 extends through one end portion of the member 32 and an end portion of the bracket 28 remote from shank 24 as well as a cylindrical spacer 62 therebetween, and is secured at a threaded end portion 64 in a fixed position with nuts 66 and 68. A free end portion 70 of member 32 extends through a slot 72 in shank 24. The slot serves to guide movements of member 32 about pivotal axis 58 and to limit, by engagement of its upper end 74 with portion 70 of the member 32, upward movement of the member 32 as well as of member 30. A torsion spring 76 wrapped around spacer 62 and having opposite ends 78 and 80 which respectively engage sole plate 26 and a right angle tab 82 on member 32 biases member 32 upwardly about its pivotal axis to the position defined by the upper end 74 of slot 72. However, member 32 is movable downwardly against the biasing force of spring 76 by engagement of a shank 84 on needle clamp 44 with member 32 as the shank enters a trough 86 in side bracket 28 during downward strokes of the needle bar.
The needle bar 14, when in a raised position, jogs in the head end portion 10 of the machine from one to another of slightly angular alternate positions on opposite sides of a central position to provide for the formation of zig-zag stitches, and then descends in the assumed position to present thread T in the needle for seizure by a hook (not shown) in the bed of the machine, all as well understood for zig-zag lockstitch sewing machines.
With the attachment 18 in place zig-zag stitches are formed over elongated member 30 which is aligned with the central position of the needle bar. As the needle bar 14 descends, needle 40 is moved downwardly with thread T along a somewhat angular path extending to one side of member 30 (FIG. 1) and passes through materials being sewn to present the thread T for seizure by the hook in the bed. After seizure by the hook, the needle is moved upwardly and out of the materials, by the needle bar, the thread is drawn tight by the usual take-up (not shown) and the needle bar jogs to a new position. The needle bar and needle descend again and the needle moves with thread T along an angular path extending to the side of elongated member 30 opposite from which the needle had passed this member on the preceeding downward stroke to again present the thread to the hook of the machine for seizure (see FIG. 2). After seizure by the hook, the needle is moved upwardly as before, the thread is drawn tight and the needle bar is jogged across the central position.
During the latter portion of each downward movement of needle 40, member 32 is pressed downwardly by engagement of the shank 84 of needle clamp 44 with a top edge portion 86 of member 32, and member 30 with thread T held over its top edge by the needle is moved downwardly to a depressed position from an elevated position defined by the engagement of the free end portion 70 of member 30 with the upper end 74 of slot 72 in the shank 24 of attachment 18. Member 30 is returned by spring 76 to its elevated position during the initial portion of the upward stroke of the needle bar, and thread held over the member by the needle is then raised by the member to the elevated position. When the thread is drawn tight in a raised position of the needle above the work a loop 88 of a height defined by the elevated position of member 30 is completed.
A series of loops 88 may be formed in the manner described over member 30 in materials moved under the needle by a work feeding feed dog of conventional design. Loops 88 may be shed from member 30 continuously one by one as materials being sewn are advanced in small steps, or a series of loops formed with small advances of the materials may be shed all at once, as when tacking, by having the material fed a substantially greater distance than the small step advances between recurring series of the small advances.
Downward movement of member 30 during the latter portion of each downward movement of the needle 40 as already described keeps elongated member 30 out of the way of the upper diverging end 90 of the needle during its descent. Attachment 18 may therefor be constructed to provide for an elevated position of the member as high as may be required to assure the formation of long loops 88. This is in contrast to loop supporting attachments with fixed loop supporting members which if disposed high above the work would interfere with the needle causing damage to one or both engaging parts.
It should be understood that the present disclosure relates to only a preferred structural arrangement of the invention and should not be construed as a limitation thereof. Numerous alterations and modifications of the structure herein disclosed will suggest themselves to those skilled in the art, and all such modifications and alterations which do not depart from the spirit and scope of the invention are intended to be included within the scope of the appended claims.
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A tailor tacking device attachable to the presser bar of a zig-zag sewing machine is provided with an elongated member to support the loops of zig-zag stitches and move from an elevated to a depressed position during downward movement of a needle bar to avoid having the supporting member interfere at such time with the needle of the machine.
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[0001] This application claims priority from Korean Patent Application No. 10-2007-0089512 filed on Sep. 4, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a laundry treatment machine and a method of controlling the motor of the laundry treatment machine, and more particularly, to a laundry treatment machine and a method of controlling the motor of the laundry treatment machine capable of preventing the motor from being restrained and of improving the mobility of the motor.
[0004] 2. Discussion of the Related Art
[0005] In general, a laundry treatment machine is divided into a washing machine for detaching contaminants attached to the laundry such as clothes and bedclothes using water, detergent, and a mechanical operation, a drier for drying the wet laundry using dry and hot wind heated by a heater and a mechanical operation, and a dry washing machine for both washing and drying.
[0006] A conventional laundry treatment machine drives a motor to rotate in a clockwise direction or a counter-clockwise direction in a uniform time. The speed of the motor is sensed to sense whether the motor is restrained in accordance with the sensed speed. When the motor is restrained, in order to release the motor, the direction of rotation of the motor is rapidly changed into an opposite direction.
[0007] However, when the motor temporarily stops in order to change the direction of rotation of the motor, abnormal noise is generated and current is excessively supplied while the motor is stopped so that the temperature of the motor rapidly rises.
SUMMARY OF THE INVENTION
[0008] In order to solve the above-described problems, it is an object of the present invention to provide a laundry treatment machine and a method of controlling the motor of the laundry treatment machine capable of preventing the motor from being restrained and of improving the mobility of the motor.
[0009] In order to achieve the above object, a laundry treatment machine includes a motor for rotating a drum to which laundry is input and a controller for driving the motor by setting a rotation starting point of the motor back from an initial setting position when it is determined that a load of the motor is no less than a previously set load.
[0010] The laundry treatment machine further includes a hall sensor for sensing current applied to the motor. The controller receives information on a period of the current applied to the motor from the hall sensor to determine the load of the motor in accordance with the received information.
[0011] The laundry treatment machine further includes an inverter module for changing a magnitude of the current applied to the motor. The controller receives information on the magnitude of the current applied to the motor from the inverter module to determine the load of the motor in accordance with the received information.
[0012] A method of controlling a motor of a laundry treatment machine includes driving a motor in an initial setting position, sensing a load of the motor when the motor is driven, and driving the motor by setting a rotation starting point of the motor back from the initial setting position when it is determined that the load of the motor is no less than a previously set load in sensing the load of the motor.
[0013] In sensing the load of the motor, the magnitude of the current applied to the motor is sensed to determine the load in accordance with the magnitude of the sensed current.
[0014] In sensing the load of the motor, a period of the current applied to the motor is sensed to determine the load in accordance with the period of the sensed current.
[0015] Sensing the load of the motor includes sensing the period of the current applied to the motor and sensing the magnitude of the current applied to the motor. The load of the motor is determined in accordance with the period of the sensed current and the magnitude of the sensed current.
[0016] When the period of the sensed current is larger than a period of a previously set current, the magnitude of the current applied to the motor is sensed.
[0017] When the magnitude of the sensed current is larger than a magnitude of previously set current, it is determined that the load of the motor is no less than a previously set load.
[0018] In driving the motor backward, the rotation starting point of the motor is set to be a position moved from the initial setting position in the opposite direction to the direction of rotation of the motor at a predetermined angle to drive the motor.
[0019] The motor is driven backward when the motor is re-driven after the motor is driven for a set time and then, is stopped.
[0020] When it is determined that the load of the motor is smaller than the previously set load in sensing the load of the motor, the rotation starting point of the motor is set to be the initial setting position to drive the motor when the motor is re-driven after the motor is driven for a set time and then, is stopped.
[0021] A method of controlling a motor of a laundry treatment machine, includes driving a motor from an initial setting position, sensing a magnitude and a period of current applied to the motor when the motor is driven to determine a load of the motor, stopping the motor when a set time has passed after the motor is driven, and, when it is determined that the load of the motor is no less than a previously set load in sensing the load of the motor, driving the motor by setting a rotation starting point of the motor back from the initial setting position when the motor is re-driven.
[0022] In the laundry treatment machine according to the present invention and a method of controlling the motor of the laundry treatment machine, when it is sensed that the motor is overloaded, the motor is driven by setting the rotation starting point of the motor back from the previously set position. Therefore, the motor is prevented from being restrained due to the overload of the motor so that it is possible to prevent the abnormal noise of the motor from being generated, to prevent the temperature from rising, and to improve the mobility of the motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a block diagram illustrating the structure of a drum washing machine according to an embodiment of the present invention;
[0024] FIG. 2 is a flowchart illustrating a method of controlling the drum washing machine according to an embodiment of the present invention; and
[0025] FIG. 3 schematically illustrates the rotation starting point of a motor according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Hereinafter, a drum washing machine as an embodiment of a laundry treatment machine according to the present invention will be described with reference to the drawings.
[0027] FIG. 1 is a block diagram illustrating the structure of a drum washing machine according to an embodiment of the present invention.
[0028] Referring to FIG. 1 , the drum washing machine includes a motor 2 for rotating a drum to which the laundry is input, a hall sensor 4 for sensing current applied to the motor 2 , an inverter module 6 for sensing the magnitude of the current applied to the motor 2 , and a controller 10 for controlling the motor 2 through information received from the hall sensor 4 and the inverter module 6 .
[0029] The drum washing machine further includes a cabinet for forming an external appearance and a tub provided in the cabinet. The drum is rotatably provided in the tub.
[0030] The hall sensor 4 is provided around the motor 2 to sense the current applied to the motor 2 and to transmit the sensed current to the controller 10 .
[0031] The inverter module 6 changes the magnitude and frequency of the current applied to the motor 2 .
[0032] The controller 10 obtains information on the period of the current applied to the motor 2 from the hall sensor 4 . In addition, the controller 10 obtains information on the magnitude of the current applied from the inverter module 6 to the motor 2 . Therefore, the controller 10 can determine the load of the motor 2 through the information on the period of the current applied to the motor 2 , which is received from the hall sensor 4 , and the information on the magnitude of the current applied to the motor 2 , which is received from the inverter module 6 .
[0033] The method of controlling the motor of the drum washing machine having the above structure will be described as follows with reference to the accompanying drawings.
[0034] FIG. 2 is a flowchart illustrating a method of controlling the drum washing machine according to an embodiment of the present invention. FIG. 3 schematically illustrates the rotation starting point of a motor according to an embodiment of the present invention.
[0035] Referring to FIG. 2 , the controller 10 drives the motor 2 . At this time, the controller 10 initially sets the rotation starting point of the motor 2 to a starting point 0 to drive the motor 2 . The controller 10 senses the load of the motor 2 .
[0036] Sending the load of the motor includes sensing the period of the current applied to the motor 2 (S 1 ) and sensing the magnitude of the current applied to the motor 2 (S 2 ). When the load of the motor 2 is large, since the magnitude and period of the current applied to the motor 2 increase, the load of the motor 2 can be determined in accordance with the magnitude and period of the current.
[0037] The controller 10 can obtain the information on the magnitude of the current applied to the motor 2 from the inverter module 6 and can obtain the information on the period of the current applied to the motor 2 from the hall sensor 4 .
[0038] In sensing the period of the current applied to the motor 2 (S 1 ), the period T of the current, which is obtained by the hall sensor 4 , is compared with the period TO of previously set current. When the period T of the current, which is obtained by the hall sensor 4 , is larger than the period TO of the previously set current, the controller 10 senses the magnitude of the current applied to the motor 2 (S 2 ).
[0039] In sensing the magnitude of the current applied to the motor 2 (S 2 ), the magnitude I of the current, which is obtained by the inverter module 6 , is compared with the magnitude 10 of the previously set current. When the magnitude I of the current, which is obtained by the inverter module 6 , is larger than the magnitude 10 of the previously set current, it is determined that the load of the motor 2 is no less than a previously set load.
[0040] Then, it is determined whether a uniform time has passed after driving the motor 2 (S 4 ). When it is determined that a uniform time has passed, the controller 10 controls the motor 2 to be stopped (S 5 ).
[0041] Then, when the motor 2 is re-driven, the motor 2 is driven by setting the rotation starting point of the motor 2 back from the starting point 0 that is the initial set position (S 6 ). That is, in driving the motor backward, the rotation starting point of the motor 2 is set to be a position moved from the starting point 0 in the opposite direction to the direction of rotation of the motor 2 at a predetermined angle.
[0042] Referring to FIG. 2 , when the motor is re-driven, the rotation starting point of the motor 2 is set to be a back position B moved backward from the starting point 0 . According to the present embodiment, the back position B is moved backward from the starting point 0 at 45 degrees. The back position B can be set to vary in accordance with the magnitude of the load sensed in sensing the load of the motor.
[0043] Driving the motor to the back position B in driving the motor backward is the laundry treatment machine as the principle of increasing leaping power using the inertia of power obtained through an approach run in athletic sports. That is, in the case where the motor is overloaded, when the motor is driven in the back position B, the mobility of the motor can be improved.
[0044] On the other hand, in sensing the period of the current applied to the motor 2 (S 1 ), when the period T of the current, which is obtained by the hall sensor 4 , is smaller than the period TO of the previously set current, the controller 10 determines that the load of the motor 2 is small.
[0045] Therefore, it is determined whether a uniform time has passed after driving the motor 2 (S 7 ). When it is determined that a uniform time has passed, the controller 10 controls the motor 2 to be stopped (S 8 ).
[0046] Then, when the motor 2 is re-driven, the direction of rotation of the motor 2 is changed into the opposite direction, the rotation starting point of the motor 2 is set to be the starting point 0 , and the motor 2 is driven (S 9 ).
[0047] In addition, in sensing the magnitude of the current applied to the motor 2 (S 2 ), when it is determined that the magnitude I of the current, which is obtained by the inverter module 6 , is smaller than the magnitude 10 of the previously set current, it is determined that the load of the motor 2 is small. Therefore, when the motor 2 is stopped and then, re-driven, the direction of rotation of the motor 2 is changed into the opposite direction and the rotation starting point of the motor 2 is set to be starting point 0 to drive the motor 2 (S 9 ).
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There are provided a laundry treatment machine and a method of controlling the motor of the laundry treatment machine. In the laundry treatment machine and the method of controlling the motor of the laundry treatment machine, when it is sensed that the motor is overloaded, the motor is driven by setting the rotation starting point of the motor back from the previously set position. Therefore, the motor is prevented from being restrained due to the overload of the motor so that it is possible to prevent the abnormal noise of the motor from being generated, to prevent the temperature from rising, and to improve the mobility of the motor.
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RELATED APPLICATION DATA
[0001] This application claims priority based on PCT/US06/002527 filed Jan. 24, 2006, U.S. patent application Ser. No. 11/041,329 filed Jan. 24, 2005, U.S. Provisional Application 60/716,323 filed Sep. 12, 2005, U.S. Provisional Application 60/728,607 filed Oct. 20, 2005, PCT/US02/23651 filed Jul. 25, 2002, U.S. Provisional Patent Application Ser. No. 60/307,824 filed Jul. 25, 2001 and of U.S. Provisional Patent Application Ser. No. 60/386,596 filed Jun. 5, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The instant invention relates to improved processes for the preparation of polynucleate aluminum hydroxyl-halide complexes and of disinfectants. The instant invention obtains simplified processes for the preparation of polynucleate aluminum hydroxyl-chloride complexes, known as polynucleate aluminum compounds (PAC) and aluminum chlorohydrate (ACH), with ACH normally used to define products having basicities of over 50% and having a higher corresponding aluminum content. All of these complexes have the general formulation Al x (OH) y Cl z .
[0004] The instant invention also obtains simplified processes for the preparation of polynucleate metal hydroxy-halide complexes having the general formulation M x (OH) y Ha z , where Ha is a halogen, preferably Cl, and M is at least one metal or group of metals in either +2 or the +3 valence state and wherein, M is added to the polynucleate aluminum hydroxy-halide metal complex in the form of the metal halide acid solution, the base metal, the metal oxide or the metal hydroxide.
[0005] As defined in this instant invention, the term metal polymer (MP) is meant to refer to any polynucleate aluminum or polynucleate metal(s) complex or compound, including those which do not contain aluminum.
[0006] These MP are intended for use in liquid solids separations, such as in water purification, sludge dewatering and paper production, as well as solids dewatering and similar dewatering applications, being delivered in solution or in solid form. These MP can be used in a variety of applications including water purification, antiperspirants, corrosion control, and conductivity. The applications for these MP are only limited by the inclusion metal(s) and the application mechanism of the associated product, whether that product is in liquid, solid or dry form.
[0007] The instant invention obtains simplified processes for MP, wherein the halogen raw material is in a salt form and is converted to an acid form via either acidification with sulfuric acid (H 2 SO 4 ) and/or sulfurous acid (H 2 SO 3 ) or with electrolysis. The instant invention obtains improved processes for the manufacture of disinfectants, wherein the disinfectant contains an oxidative element or compound, and wherein the energy of manufacture is obtained from the energy of formation from at least one selected from a list consisting of: sulfur dioxide (SO 2 ) from the burning of sulfur (S) in air or O 2 , sulfur trioxide (SO 3 ) from the oxidation of SO 2 , H 2 SO 4 formation from SO 3 , sulfurous acid (H 2 SO 3 ) formation from SO 2 with air or O 2 , halide acid formation from the reaction of a metal halide with an acid based upon an oxidation state of sulfur (a sulfoxy acid, preferably H 2 SO 4 and/or H 2 SO 3 ) and any combination therein. The instant invention obtains improved processes for the manufacture of an acid and a base, wherein said acid is based upon a halogen anion and wherein said base is based upon the hydroxyl anion. The instant invention provides for an improved process for the manufacture of gypsum, calcium sulfate di-hydrate, as well as: calcium sulfate, calcium sulfate ½ hydrate, calcium sulfite, calcium sulfite hydrate, and calcium hydrogen sulfite. The instant invention provides an economical and practical use for S, including the S removed from hydrocarbon fuels.
[0008] The processes of the instant invention: use less expensive raw materials, manage heat and chemical energy more efficiently, have lower transportation costs and require less handling of hazardous chemicals thereby requiring significantly less manufacturing cost.
[0009] 2. Description of the Prior Art and Background
[0010] PAC—Since the 1970's it has been known in the art to prepare polynucleate (or polynuclear) aluminum complexes, also known as aluminum polymers. The first products that showed promise were poly aluminum sulfates. Processes for the production of poly aluminum sulfates are disclosed and presented in U.S. Pat. Nos. 4,284,611 and 4,536,665 and Canadian Patent Nos. 1,203,364; 1,203,664; 1,203,665; and 1,123,306, while used as a reference in this instant invention. In these patents, poly aluminum sulfate is produced by reacting sulfate solutions with sodium carbonate or sodium hydroxide to form an insoluble aluminum hydroxide gel, wherein soluble sodium sulfate is then removed.
[0011] U.S. Pat. No. 4,877,597 describes another process for the production of poly aluminum sulfate, while used as a reference in this instant invention. This process eliminated the initial step of producing an aluminum hydroxide gel by reacting aluminum sulfate with sodium aluminate.
[0012] U.S. Pat. No. 3,544,476 discloses a process for the formation of a poly aluminum chloral-sulfate, while used as a reference in this instant invention. It is prepared by first producing an aluminum chloride/aluminum sulfate solution and then basifying this solution with calcium carbonate of lime. The insoluble calcium sulfate is removed.
[0013] U.S. Pat. Nos. 2,196,016; 2,392,153; 2,392,153; 2,392,531; 2,791,486; 3,909,439, and 4,082,685 disclose processes for the production poly aluminum chloride (low basicity ACH), while used as a reference in this instant invention. These processes involve reacting aluminum oxy-hydrates or aluminum hydroxy-hydrates with hydrochloric acid (HCl) under high temperature and pressure conditions.
[0014] U.S. Pat. Nos. 4,362,643 and 4,417,996 disclose processes for the production of poly aluminum-iron complexes, while used as a reference in this instant invention. These processes involve reacting aluminum chloride/iron chloride solution with aluminum hydroxide or aluminum oxy-hydrates, as well as a poly aluminum chloride with iron.
[0015] U.S. Pat. No. 4,131,545 discloses a process for the production of poly aluminum sulfate compounds by reacting aluminum sulfate with phosphoric acid and calcium sulfate, while used as a reference in this instant invention. In the water industry, it is known at this time that PAC compounds containing sulfate are known to out perform aluminum salts, iron salts, PAC and ACH in water temperatures from approximately 34 (1° C.) to approximately 40° F. (4° C.).
[0016] The most common PAC is ACH. ACH is the most common PAC due to its higher aluminum content, which significantly increases the effectiveness of the PAC in operating temperatures over 40° F. (4° C.). U.S. Pat. Nos. 4,051,028 and 4,390,445 disclose processes for the formation of a poly aluminum hydroxychloride (ACH), while used as a reference in this instant invention. It is prepared by reacting aluminum chloride solution and aluminum hydroxide with calcium carbonate or lime. Insoluble calcium carbonate is removed. U.S. Pat. Nos. 4,034,067 and 5,182,094 disclose processes for the formation of a poly aluminum hydroxychloride, while used as a reference in this instant invention. It is prepared by reacting aluminum chloride solution with alumina or aluminum hydroxide under conditions of high temperature and pressure.
[0017] U.S. Pat. No. 5,938,970 discloses a method of forming polynucleate bi-metal hydroxide complexes (2 metals are used), while used as a reference in this instant invention. This process describes the use of a trivalent metal in combination with a divalent metal, wherein the trivalent metal is in an acid solution and is reacted with the oxide or hydroxide form of the divalent metal.
[0018] WO 97/11029 (PCT/US96/13977) and U.S. Pat. No. 5,985,234 disclose a method of forming polynucleate aluminum complexes, wherein sodium aluminate is required to be reacted with either aluminum chloride or aluminum chlorosulfate, while used as a reference in this instant invention; the reaction is carried out under conditions of high shear agitation to minimize gel formation. The reaction is to be carried out at a temperature of under 50° C. producing a milky suspension which clears over time.
[0019] At this time, ACH is known to be prepared by four methods. The first method is by reacting alumina and/or aluminum hydroxide with aluminum chloride solution (ACS) in a single step process at elevated temperature or pressure or both. Alumina is defined in the instant invention as any mixture comprising primarily aluminum oxy-hydrates and/or aluminum hydroxy-hydrates as those occur in nature and as purified from raw bauxite. Raw bauxite is purified by the Bayer process which utilizes the amphoteric nature of aluminum, which allows aluminum to be soluble at high pH as well as at low pH. Other metals do not exhibit this characteristic. Thereby aluminum is purified from other metals at a pH of approximately greater than 10.0 and at high enough operating temperature to flow the aluminum oxy- and hydroxy-hydrates. The second method is by reacting HCl with an excess of alumina and/or aluminum hydroxide at elevated pressure and/or temperature. The third process is by reacting alumina and/or aluminum hydroxide with HCl and metal carbonates or metal oxides at elevated temperature and/or pressure. The fourth method, which is disclosed in U.S. Pat. No. 5,904,856, presents a method of acidifying cement in HCl or ACS. A consequence of the second and the third process is large amounts of non-reacted aluminum hydroxide material that have to be returned to the process, which makes the process considerably more expensive. A consequence of the third process is a frothing of the carbonates in the reaction vessel; further, these products do not dry well should one desire a dry final aluminum polymer. The first and fourth processes are very expensive requiring the transport of large quantities of ACS. The second, third, and fourth processes are very expensive requiring the transportation of large quantities of HCl. Depending upon the concentration, HCl is at least approximately 65 percent water and ACS is at least approximately 60 to 90 percent water; therefore, the transportation of HCl or ACS requires the transportation and handling of large quantities of water and is therefore not economical. A consequence of the fourth process is the cost of first preparing the sintered cement containing Al 2 O 3 and ClO. A consequence of all these processes is a purity limitation of the bauxite, if bauxite is used, as metal impurities in some forms of bauxite cannot be polymerized in the PAC when the PAC is used for drinking water purification.
[0020] All of these PAC and MP patent(s) are incorporated herein as a reference. All of these processes are limited with regard to the starting materials. Per any of these processes, large amounts of HCl or ACS or other metal acid solution must be handled. Per any of these processes, to prepare the ACS, HCl must be used. In summary, all require transportation, storage, and handling of large quantities of hazardous chemicals.
[0021] Further, the drinking water industry is placing restrictions on the amount of soluble aluminum in the final water product. Industrial processes have for years restricted aluminum salt coagulation to eliminate soluble aluminum in the final purified water. PAC(s) do not produce soluble aluminum in the final water. MP's do not place a soluble metal into the water. Due to requirements in both portable and industrial water coagulation, a safer, simpler and more economical process is needed for the manufacture of PAC(s) and MP(s).
[0022] Energy—None of these processes manage heat or chemical energy in an efficient manner. All of these processes require adding heat to the PAC or MP reactor and require heat in the preparation of alumina with no consideration given to the exothermic nature of either HCl or ACS formation. All of these processes require the preparation of HCl or delivery of HCl prior to ACS manufacture, while there are significant amounts of potential chemical energy available in the conversion of sodium chloride to HCl and in the conversion of aluminum to ACS utilizing HCl. Finally, none of these processes investigate either the use of H 2 SO 4 and/or H 2 SO 3 for the preparation of HCl, the very exothermic production of H 2 SO 4 and/or H 2 SO 3 from S or the very exothermic formation of HCl from a metal chloride salt reacting with H 2 SO 4 and/or H 2 SO 3 , all of which present the ability to produce heat energy, steam and electricity.
[0023] HCl—Other than the lost energy and the cost of purchase, HCl transportation has many issues, which include increased cost and environmental concerns. HCl has to be transported and suitable ventilation has to be arranged in order to eliminate the release of Hydrogen Chloride gas, HCl(g). Further, aqueous chlorine (Cl), or the chloride ion, is produced from aqueous HCl. The chlorine (Cl 2 ) production process is an expensive one that requires drying and refrigeration prior to storage. The most significant issue with Cl 2 is storage. Cl 2 is an extremely hazardous chemical to store; therefore, storage of Cl 2 is expensive. The hazardous nature of Cl 2 has, in recent years, caused many water purification facilities to reevaluate the usage of Cl 2 versus bleach or other disinfectants.
[0024] Upon contact with water, Cl 2 forms both the chloride ion and the chlorite ion. The chlorite ions are decomposed into chloride ions with temperature. The addition of heat to large volumes of liquid is also very expensive. Moreover, HCl must be stored and transported in polymer-lined containers where the releases of HCl(g) vapors must be controlled. In summary, the production and transportation of HCl and/or Cl 2 is both expensive and hazardous.
[0025] ACS—ACS is formed by the reaction of HCl with aluminum hydroxide, alumina (aluminum hydroxide and/or aluminum oxide in the dry or hydrate form) or aluminum. While ACS can be prepared from bauxite, this is not preferred in most applications because the acidification of aluminum in bauxite to ACS can also acidify any other metal impurities that may be present in the raw bauxite. Formation of ACS also releases HCl(g), which must be controlled. This is an expensive process. Therefore, in summary, the current processes always provide complications leading to increases in the cost of the final product, as well as many safety concerns which must be managed.
[0026] Disinfectants and oxidants—Further yet, in all applications of water purification, there are efforts to eliminate the formation of chloro-organic compounds, which have been found to be at least one of: toxic, carcinogenic, teratogenic and any combination therein. The drinking water industry is limiting Cl 2 and bleach disinfection, investigating alternative disinfectants such as H 2 O 2 , O 2 , ozone (O 3 ) and chlorine dioxide (ClO 2 ). The power industry has learned that those same chloro-organic compounds prematurely contaminate demineralizer beds, thereby resulting in the use of such alternative such as H 2 O 2 , O 2 , O 3 and ClO 2 . The paper industry has learned that those same chloro-organic compounds are found in both the final paper product and in the plant wastewater, thereby requiring investigation of alternatives such as H 2 O 2 , O 2 and O 3 . The manufacture of O 3 requires O 2 , which is an expensive product formed by either separation of air or electrolysis of water. Also, ClO 2 is an extremely hazardous chemical to transport, thereby requiring on-site generation from other Cl 2 compounds, such as bleach (hypochlorite), chlorite and chlorate. Previous work in the manufacture of chlorite and chlorate is referenced herein in U.S. Pat. Nos. 2,092,944; 2,092,945; 2,194,494; 2,323,180; 2,616,783; 2,833,624; 3,101,248; 3,450,493; 3,760,065; 3,760,065; 3,828,097; 3,997,462; 4,081,520; 4,086,329; 4,087,515; 4,421,730; 4,465,658; 4,473,540; 4,683,039; 5,091,166; 5,091,167; 5,116,595; 5,205,995; 5,366,714; 5,593,653; 5,597,544; 5,639,559; and 6,251,357; along with 2189289 from CA; 55-098965 from JP and 56-92102 from JP. All of these patents are used as a reference to the instant invention.
[0027] While there are many methods to prepare H 2 O 2 , there are two primary chemical manufacturing processes: the hydroquinone (HQ) process and the sulfuric acid/electrolysis (SAE) process. Historically, SAE was the preferred process until the 1960's and 1970's wherein industry converted to HQ due to the operating cost savings of eliminating the electrical cost associated with SAE. However, by its nature, HQ has a limitation of organic contamination, which is due to the use of an organic chemical (hydroquinone) as a catalyst. Further, the discovery of chloro-organic toxicity has lead industry to require more pure forms of H 2 O 2 . In H 2 O 2 manufacturing, membranes have been discussed as methods of H 2 O 2 purification. U.S. Pat. Nos. 4,879,043 and 6,333,018 present the use of reverse osmosis membrane technology as a final purification step in the production of H 2 O 2 manufactured by HQ, while used as a reference in this instant invention. U.S. Pat. Nos. 5,215,665; 5,262,058 and 5,906,738 present the use of reverse osmosis membrane technology in combination with cabonic resin technology as final purification steps in the production of H 2 O 2 manufactured by HQ, while used as a reference in this instant invention. U.S. Pat. Nos. 5,851,042 and 6,113,798 present the use of converting contaminant particles by reacting said particles with micro-ligands, then separating said reaction products with membranes as a final purification step in the production of H 2 O 2 manufactured by HQ, while used as a reference in this instant invention. U.S. Pat. No. 5,800,796 presents an electrochemical reactor wherein O 2 and H 2 are reacted across a conductive membrane containing reducing catalysts forming H 2 O 2 , while used as a reference in this instant invention. This process eliminates HQ while simplifying the process H 2 O 2 production. However, the potential for contamination of H 2 O 2 with heavy metals from the reducing catalyst is significant. Heavy metals contamination eliminates the potential use of H 2 O 2 in either the production of micro-circuitry or water purification. In addition, the potential safety issues from the reaction of very explosive O 2 and/or H 2 in an electrolytic environment preclude the potential use of this process at the end-use site. U.S. Publication 20040126313 teaches the use of membrane technology in combination with SAE; however, a source of electricity is not presented. None of these references present SAE with a source of electricity. All of these H 2 O 2 patents are incorporated herein as a reference.
[0028] While there are many methods to prepare O 2 , the separation of air into its component gases is performed by three methods: cryogenic distillation, membrane separation and pressure swing adsorption (PSA, which includes vacuum). Conventional cryogenic distillation processes that separate air into O 2 , Argon (Ar) and nitrogen (N 2 ) are commonly based on a dual pressure cycle. Air is first compressed and is subsequently cooled, wherein cooling is accomplished by one of four methods: 1—vaporization of a liquid, 2—the Joule Thompson effect; 3—counter-current heat exchange with previously cooled warming product streams or with externally cooled warming product streams, and 4—the expansion of a gas in an engine doing external work. The cooled and compressed air is usually introduced into two fractioning zones. The first fractioning zone is thermally linked with a second fractioning zone which is at a lower pressure. The two zones are thermally linked such that a condenser of the first zone reboils the second zone. Air undergoes a partial distillation in the first zone producing a substantially pure N 2 fraction and a liquid fraction that is enriched in O 2 . The enriched O 2 fraction is an intermediate feed to the second fractioning zone. The substantially pure N 2 from the first fractioning zone is used as reflux at the top of the second fractioning zone. In the second fractioning zone, separation is completed producing substantially pure O 2 from the bottom of the zone and substantially pure N 2 from the top. When Ar is produced or removed a third fractioning zone is employed. The feed to this third zone is a vapor fraction enriched in Ar which is withdrawn from an intermediate point in the second fractioning zone. The pressure of this third zone is of the same order as that of the second zone. In the third fractioning zone, the feed is rectified into an Ar rich stream which is withdrawn from the top, and a liquid stream which is withdrawn from the bottom of the third fractioning zone and introduced to the second fractioning zone at an intermediate point. Reflux for the third fractioning zone is provided by a condenser which is located at the top. In this condenser, Ar enriched vapor is condensed by heat exchange from another stream, which is typically the enriched O 2 fraction from the first fractioning zone. The enriched O 2 stream then enters the second fractioning zone in a partially vaporized state at an intermediate point above the point where the feed to the third fractioning zone is withdrawn.
[0029] The distillation of air, which is a ternary mixture into N 2 , O 2 and Ar, may be viewed as two binary distillations. One binary distillation is the separation of the high boiling point O 2 from the intermediate boiling point Ar. The other binary distillation is the separation of the intermediate boiling point Ar from the low boiling point N 2 . Of these two binary distillations, the former is more difficult, requiring more reflux and/or theoretical trays than the latter. Ar—O 2 separation is the primary function of the third fractioning zone and the bottom section of the second fractioning zone below the point where the feed to the third zone is withdrawn. N 2 —Ar separation is the primary function of the upper section of the second fractioning zone above the point where the feed to the third fractioning zone is withdrawn. The ease of distillation is a function of pressure. Both binary distillations become more difficult at higher pressure. This fact dictates that for the conventional arrangement, the optimal operating pressure of the second and third fractioning zones is at or near the minimal pressure of one atmosphere. For the conventional arrangement, product recoveries decrease substantially as the operating pressure is increased above one atmosphere mainly due to the increasing difficulty of the Ar—O 2 separation. There are other considerations, however, which make elevated pressure processing attractive. Distillation column diameters and heat exchanger cross sectional areas can be decreased due to increased vapor density. Elevated pressure products can provide substantial compression equipment capital cost savings. In some cases, integration of the air separation process with a power generating gas turbine is desired. In these cases, elevated pressure operation of the air separation process is required. The air feed to the first fractioning zone is at an elevated pressure of approximately 10 to 20 atmospheres absolute. This causes the operating pressure of the second and third fractioning zones to be approximately 3 to 6 atmospheres absolute. Operation of the conventional arrangement at these pressures results in very poor product recoveries due to the previously described effect of pressure on the ease of separation. Previous work to cryogenically separate air into its components can be referenced in U.S. Pat. Nos. 5,386,692; 5,402,647; 5,438,835; 5,440,884; 5,456,083; 5,463,871; 5,582,035; 5,582,036; 5,596,886; 5,765,396; 5,896,755; 5,934,104; 6,173,584; 6,202,441; 6,263,700; 6,347,534; 6,536,234; 6,564,581; 5,341,646; 5,245,832; 6,048,509; 6,082,136; 6,499,312; 6,298,668; and 6,333,445. All of these cryogenic patents are incorporated herein as a reference.
[0030] It is also well known in the chemical industry to separate air with membranes. Two general types of membranes are known in the art: organic polymer membranes and inorganic membranes. These membrane air separation processes are improved by setting up an electric potential across a membrane that has been designed to be electrically conductive. Previous work performed to separate air into its components with membranes can be referenced in U.S. Pat. Nos. 6,523,529; 6,761,155; 6,277,483; 5,820,654; 6,293,084; 6,360,524; 6,551,386; 6,562,104; 6,361,583; 6,565,626; 6,572,678; 6,572,679; 6,579,341; 6,592,650; 6,372,010; 5,599,383; 5,820,654; 5,820,655; 5,837,125; 6,117,210; 5,599,383; 5,902,370; 6,117,210; 6,139,810; 6,403,041; and 6,767,663. All of these membrane patents are herein incorporated as reference. While these patents present many innovations in membrane technology, none present use of a membrane wherein the energy of air separation is obtained from the formation energy of at least one selected from a list consisting of: SO 2 from the burning of S in air or O 2 , SO 3 from the oxidation of SO 2 , H 2 SO 4 formation from SO 3 , H 2 SO 3 formation from SO 2 , halide acid formation and any combination therein.
[0031] It is also well known to separate air into O 2 and N 2 with PSA (herein to include vacuum swing adsorption). Previous work performed to separate air into its components with PSA can be referenced in U.S. Pat. Nos. 6,572,838; 6,761,754; 6,780,806; 3,793,931; 4,481,018; 4,544,378; 5,464,467; 5,810,909; 5,868,818; 5,885,331; 6,350,298; 6,171,370; 6,423,121; 6,649,556; 6,652,626; 4,013,429; 4,264,340; 4,329,158; 4,685,939; 5,137,548; 5,152,813; 5,258,058; 5,268,012; 5,354,360; 5,413,625; 5,417,957; 5,419,891; 5,454,857; 5,672,195; 6,004,378; 6,357,601; 6,321,915; 6,315,884; 6,298,664; 6,497,098; 6,510,693; and 6,516,787. All of these PSA patents are herein incorporated as reference. While these patents present many innovations in PSA technology, none teach wherein the energy of manufacture is obtained from the formation energy of at least one selected from a list comprising: SO 2 from the burning of S in air or O 2 , SO 3 from the oxidation of SO 2 , H 2 SO 4 formation from SO 3 , H 2 SO 3 formation from SO 2 , halide acid formation and any combination therein.
[0032] An additional method for the manufacture of O 2 is the electrolysis of water (H 2 O). Previous work in the electrolysis of H 2 O can be referenced in U.S. Pat. Nos. 6,723,220; 5,585,882; 6,572,759; 6,551,735; 6,471,834; 6,361,893; 6,338,786; and 6,336,430. All of these electrolysis patents are herein incorporated as reference. While these patents present many innovations in electrolysis technology, none present wherein the energy of manufacture is obtained from the energy of formation from at least one selected from a list comprising: SO 2 from the burning of S in air or O 2 , SO 3 from the oxidation of SO 2 , H 2 SO 4 formation from SO 3 , H 2 SO 3 formation from SO 2 , halide acid formation and any combination therein.
[0033] It is well known in the art of methods and processes to manufacture oxides of halogens to form said halogen oxide from a metal/halogen salt via electrolysis. While the most common metal is sodium, calcium is often used. While the most common halogen is chlorine, bromine, fluorine and iodine are often used. Previous work in the production of halogen oxide manufacture can be referenced in U.S. Pat. Nos. 5,342,601; 5,376,350; 5,409,680; 5,419,818; 5,423,958; 5,458,858; 5,480,516; 5,523,072; 5,565,182; 5,599,518; 5,618,440; 5,681,446; 5,779,876; 5,851,374; 5,858,322; 5,916,505; 5,972,196; 6,004,439; 6,203,688; 6,306,281; 6,436,435; 6,740,223; 6,761,872; 6,805,787; and 6,814,877. All of these patents in the preparation of an oxide form of a halogen are herein incorporated as reference. While these patents present many innovations in the production of halogen oxides, none present wherein the energy of manufacture is obtained from the energy of formation from at least one selected from a list comprising: SO 2 from the burning of S in air or O 2 , SO 3 from the oxidation of SO 2 , H 2 SO 4 formation from SO 3 , H 2 SO 3 formation from SO 2 , halide acid formation and any combination therein.
[0034] Acid Manufacture (Sulfuric, Sulfurous and Hydrochloric)—HCl is known in the art to be produced by 2 processes, the Electrolysis Unit (EU) process and the Sulfuric Acid Process (SAP). The raw materials for EU production of HCl include sodium chloride, water, and electricity. The raw materials for SAP production of HCl include sodium chloride, H 2 SO 4 and water.
[0035] Sulfuric acid has many forms and equivalents, all of which are based upon the sulfoxy (S x O y ) anion moiety, wherein X can vary from 1 to 2 and Y can vary from 2 to 8. Examples would be sulfurous acid, sulfuric acid, oleum and persulfuric acid. As defined in this instant invention a sulfoxy acid is any proton donating acid containing a sulfoxy moiety. H 2 SO 4 and H 2 SO 3 are manufactured primarily by two competing processes, the condensation process and the contact process. In both cases, in a sulfuric acid plant, which will be herein after referred to as the sulfuric acid reactor (SAR), S is combusted in air and/or O 2 to produce SO 2 . SO 2 is then converted into SO 3 in the contact process with the use of a catalyst, usually V 2 O 5 , in the presence of excess air at a temperature of about 400-450° F. (204-233° C.). In either process, SO 3 can be slowly converted into H 2 SO 4 by contact of said SO 3 with H 2 O. In the condensation process, the combusted SO 2 is contacted with H 2 O quickly forming H 2 SO 3 and slowly forming H 2 SO 4 . In the contact process, said SO 3 is contacted with H 2 SO 4 forming H 2 S 2 O 7 (oleum); oleum is then contacted with H 2 O forming 100 percent H 2 SO 4 . Often the oleum step is bypassed by directly reacting said SO 3 with H 2 SO 4 and H 2 O, thereby forming H 2 SO 4 . It is difficult to obtain 100 percent H 2 SO 4 with the condensation process.
[0036] Bleach Manufacture—Bleach, a group IA or group IIA metal in solution with a hypohalite, is currently manufactured by two processes, electrolysis and acid/base blending. In electrolysis, a salt solution comprising a group IA or group IIA metal halide is placed in an electrolysis cell, wherein the salt is separated into the corresponding halide acid and the corresponding group IA or group IIA hydroxide, and wherein said halide acid and said group IA or group IIA hydroxide is allowed to mix, therein forming the corresponding group IA or group IIA metal in solution with the hypohalite while releasing hydrogen gas. In acid/base blending, a cold dilute solution of a group IA or group IIA metal hydroxide is mixed with either a halogen acid in aqueous form or with a halogen acid gas, wherein is formed the corresponding group IA or group IIA metal in solution with the hypohalite while releasing hydrogen gas. In all situations, concentration of the group IA or group IIA metal hypohalite in solution may be increased by adding an excess of a base, preferably the group IA or group IIA hydroxide until a concentration of about 15 percent of the group IA or group IIA metal hypohalite is obtained.
[0037] Under current manufacturing practices, the group IA or group IIA metal hydroxide used in the formation of a bleach is formed by the electrolysis of the corresponding group IA or group IIA salt in water. Therefore, the manufacture of any bleach is currently constrained by the cost and/or availability of electricity to perform electrolysis.
[0038] Previous work in the manufacture of a group IA or group IIA hydroxide are referenced herein in U.S. Pat. Nos. 3,976,556; 4,025,405; 4,100,050; 4101,395; 4,187,350; 4,221,644; 4,240,883; 4,295,944; 4,486,276; 4,586,994; 4,969,981; 6,488,833; along with A 1 067 215 from EP; 1120481 from EP; 55-89486 from JP; 1-234585 from JP; and 10-110287 from JP. All of these bleach patents are herein incorporated as reference.
[0039] Gypsum Manufacture—Gypsum, calcium sulfate di-hydrate, is a widely used product being the major component in the manufacture of wall-board or sheetrock. Gypsum is currently manufactured by three competing processes: the mining of calcium sulfate di-hydrate, the hydration of mined calcium sulfate and the scrubbing of waste sulfoxy acid gases by an oxide of calcium, usually calcium oxide and/or calcium hydroxide. In all cases, the purity of manufactured gypsum is an issue. In the case of mined calcium sulfate and calcium sulfate di-hydrate, contaminants from the earth are an issue. And, in the case of scrubbing waste sulfoxy acid gases, impurities in the gas stream are often also oxidized and left in the gypsum product.
[0040] Previous work performed to purify a sulfoxy acid gas, thereby forming gypsum are herein referenced in U.S. Pat. Nos. 3,976,747; 4,312,280; 4,590,049; 4,782,772; 4,867,955; 4,915,920; 4,931,264; 5,006,323; 5,345,884; 5,538,703; 5,544,596; 5,551,357; 5,795,548; 5,814,288; 6,290,921; 6,309,996 and 6,912,962, along with foreign patents 40 39 213 from DE, 40 23 030 from DE, 2 107 207 from GB and 99/5822/6 from WO. All of these gypsum patents are herein incorporated as reference.
[0041] Transportation of Hazardous Chemicals and Sulfur Management—As population density increases, the transportation of hazardous chemicals, including acids and disinfectants, leads to an increased incidence of spills while the consequences of spills become more serious. While solutions of halide acid, hypohalite and halite are safer disinfectants for transportation, handling, and storage, the cost of manufacture of these disinfectants has limited their use. A more economical process is required for the manufacture of O 2 , ClO 2 , halide acid, hypohalite, and halate. In addition, while the US EPA is requiring the removal of sulfur from hydrocarbon fuels, thereby limiting atmospheric releases of oxides of sulfur from combustion exhaust, said removal is creating an abundance of sulfur, such that the petroleum refining industry is in need of a way to dispose of said abundance of sulfur.
SUMMARY OF THE INVENTION
[0042] A primary object of the instant invention is to devise an effective, efficient, and economically feasible process for producing polynucleate aluminum and/or polynucleate metal complexes.
[0043] Another object of the instant invention is to devise an effective, efficient, and economically feasible process for producing polynucleate aluminum and/or polynucleate metal complexes without the transportation and handling of hazardous materials.
[0044] Still another object of the instant invention is to devise an effective, efficient, and economically feasible process for producing polynucleate complexes that contain metals in addition to and/or instead of aluminum.
[0045] Still yet another object of the instant invention is to devise an effective, efficient, and economically feasible process for producing disinfectants and/or oxidants, preferably those utilized in the water treatment and the paper industries, specifically: O 2 , O 3 , H 2 O 2 , NaOH, H 2 O 2 , hypohalite, halite, halate, halogen oxides and halide acids.
[0046] Still further yet another object of the instant invention is to devise an effective, efficient, and economically feasible process for producing HCl and H 2 SO 4 , as well as metal sulfites, metal bisulfites and metal sulfates.
[0047] Still further yet another object of the instant invention is to devise an effective, efficient, and economically feasible process for using the energy of formation from at least one selected from a list consisting of: SO 2 from sulfur and air or oxygen, SO 3 from SO 2 and air or oxygen with a catalyst, H 2 SO 4 from oleum and water, H 2 SO 4 from H 2 SO 3 , H 2 SO 4 and water, and any combination therein to make steam, wherein said steam is used to generate electricity to manufacture by electrolysis at least one selected from a list consisting of: O 2 and H 2 from H 2 O, O 3 from O 2 , H 2 O 2 from water using H 2 SO 4 as a catalyst, a metal hydroxide and a hydrogen halide from said metal halide, a hypohalite, a halite, a halate, a halogen oxide, and any combination therein.
[0048] Still further yet also another object of the instant invention is to devise an effective, efficient, and economically feasible process for using the energy of formation from at least one selected from a list consisting of: SO 2 from sulfur and air or oxygen, SO 3 from SO 2 and air or oxygen with a catalyst, H 2 SO 4 from oleum and water, H 2 SO 4 from H 2 SO 3 , H 2 SO 4 and water, and any combination therein to make steam, wherein said steam is used to generate mechanical energy to manufacture at least one selected from a list consisting of: O 2 and H 2 from H 2 O.
[0049] Still further also yet another object of the instant invention is to devise an effective, efficient, and economically feasible process for the chemical manufacture of bleach, wherein the group IA or group IIA metal hydroxide is manufactured without the need of electrolysis.
[0050] Still also further yet another object of the instant invention is to devise an effective, efficient, and economically feasible process for the chemical manufacture of gypsum, wherein the purity of the gypsum is increased.
[0051] And, still also further yet another object of the instant invention is to devise an effective, efficient, and economically feasible process for the chemical manufacture of gypsum, wherein the sulfur incorporated in said gypsum is from the removal of said sulfur from a hydrocarbon.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] A better understanding of the instant invention can be obtained when the following preferred embodiments are considered in conjunction with the following drawings, in which:
[0053] FIG. 1 illustrates a legend for FIGS. 2 through 12 .
[0054] FIG. 2 illustrates in block diagram form a general description of a preferred embodiment of the proposed methods and processes to manufacture disinfectants with electrolysis, wherein the energy for electrolysis is obtained from the formation of at least one selected from a list consisting of: SO 2 , SO 3 , H 2 SO 3 , oleum, H 2 SO 4 and any combination therein. FIG. 2 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], and Electrolysis Unit [ 3 ].
[0055] FIG. 3 illustrates in block diagram form a general description of a preferred embodiment of the above methods and processes in combination with a process for halogen acid reaction (HAR), wherein a sulfoxy acid, preferably, H 2 SO 4 and/or H 2 SO 3 , is reacted with a metal halide salt to form the corresponding halide acid, along with the corresponding metal sulfoxy salt, most preferably the metal sulfate, sulfite or bisulfite. FIG. 3 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], and HAR [ 4 ].
[0056] FIG. 4 illustrates in block diagram form a general description of a preferred embodiment of the methods and process in FIGS. 1 and 2 in combination with the manufacture of a PAC and/or an MP. FIG. 4 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], HAR [ 4 ], and MPR and/or AHR and/or MAS [ 12 ].
[0057] FIG. 5 illustrates in block diagram form a general description of a preferred embodiment, wherein H 2 produced in electrolysis is recycled as an energy source for electrolysis to improve the economics of electrolysis. FIG. 5 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], and Combustion Engine Generator or Fuel Cell [ 13 ].
[0058] FIG. 6 illustrates in block diagram form a general description of a preferred embodiment comprising a steam turbine, wherein air separation, preferably cryogenic distillation, is used to produce O 2 and electrolysis is used to turn said O 2 into O 3 . FIG. 6 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], and Air Separation Unit [ 14 ].
[0059] FIG. 7 illustrates in block diagram form a general description of a preferred embodiment comprising a steam engine, wherein air separation, preferably cryogenic distillation, is used to produce O 2 and electrolysis obtains electricity via a steam turbine/generator to turn said O 2 into O 3 . FIG. 7 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], and Air Separation Unit [ 14 ].
[0060] FIG. 8 illustrates in block diagram form a general description of a preferred embodiment, wherein the H 2 produced in electrolysis is recycled as an energy source for electrolysis to improve the economics of electrolysis. FIG. 8 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], HAR [ 4 ], MPR and/or AHR and/or MAS [ 12 ], and Combustion Engine Generator or Fuel Cell [ 13 ].
[0061] FIG. 9 illustrates in block diagram form a general description of a preferred embodiment, wherein air separation, preferably cryogenic distillation, is used to produce O 2 ; electrolysis obtains electricity via a steam turbine/generator to turn said O 2 into O 3 . FIG. 9 illustrates a process flow diagram including the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], HAR [ 4 ], MPR and/or AHR and/or MAS [1,2], and Air Separation Unit [ 14 ].
[0062] FIGS. 10 and 11 illustrate in block diagram form a general description of a preferred embodiment of the proposed methods and processes to manufacture the halide acid and the metal sulfoxy salt from a sulfoxy acid and a metal halide salt, wherein said manufacture is to occur in an extruder and/or auger type of reactor, wherein the screw in said reactor transfers said metal halide salt into reaction with said sulfoxy acid, wherein said halide acid is removed from at least one vented portion of said extruder and/or auger, wherein said extruder and/or auger transfers said metal sulfoxy salt from said extruder and/or auger at an end opposite of the entry of said metal halide salt. FIG. 10 illustrates a metal hydroxide to pH adjust said metal sulfoxy salt, thereby creating said metal sulfoxy salt from any excess said sulfoxy acid while releasing water in at least one vented portion of said extruder and/or auger reactor. As FIG. 10 illustrates two vents, one for said halide acid and one for said water vapor, it is an embodiment to have one vent, two vents, or more vents. It is preferred that a heated water jacket be placed on said extruder and/or auger. It is most preferred that said water jacket flow co-current to said reaction of said metal halide salt with said sulfoxy acid. It is preferred that said extruder and/or auger and said water loop be as is known in the art of such equipment. FIGS. 10 and 11 illustrate the HAR [ 4 ], including a process flow diagram incorporating the Enclosed Halide Acid Vent [ 15 ], Enclosed H 2 O Vent [ 16 ], Metal Halide Salt Feeder [ 17 ], Auger with Variable Frequency Drive (VFD) [ 18 ], Sulfoxy Acid Pump with VFD [ 19 ], Controller [ 20 ], Metal Hydroxide Pump with VFD [ 21 ], pH Measurement [ 22 ], Controller [ 23 ], Water Circulation Pump [ 24 ], Vent Scrubber [ 25 ], Eductor(s) [ 26 ], Water Control Valve [ 27 ], Specific Gravity Measurement [ 28 ], Controller [ 29 ], and Burner [ 30 ].
[0063] FIG. 12 illustrates in block diagram form a general description of a preferred embodiment, wherein sulfur, alumina, a metal halide salt and water are used to produce a polynucleate metal compound, a metal halide solution, a metal halite, a metal hypohalite, a metal hydroxide, and calcium sulfate dehydrate. FIG. 12 illustrates a process flow diagram incorporating the SACP [ 1 ], Steam Turbine and Generator [ 2 ], Electrolysis Unit [ 3 ], HAR [ 4 ], Slaker [ 5 ], Gypsum Unit [ 6 ], Separator(s) [ 7 ], Metal Halite Unit [ 8 ], Halogen Dioxide Unit [ 9 ], Dryer [ 10 ], Bleach Unit [1,1], and MAR and/or MPR [ 12 ].
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0000] Chemical Equilibria
[0064] Chemical Equilibria and/or reactions which comprise an aspect of the instant invention include but are not limited to:
Reactions which are most preferred comprise at least one selected from a list consisting of number: 1, 2, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 17, 19, 25, 26, and any combination therein. Reactions required to remove calcium and thereby increase product purity are 11 and 12. Reaction 26 is preferred for on-site manufacture of chlorine dioxide. Alumina is herein estimated at about ⅔ aluminum oxide and ⅓ aluminum hydroxide; however, Alumina can be any concentration of the base aluminum metal with any concentration of aluminum oxide and/or any concentration of aluminum hydroxide. It is preferred to use at least one metal other than aluminum.
Sulfoxy Acid Formation—SAR
[0065] Significant economies of manufacture can be obtained by the preparation of a sulfoxy acid. A sulfoxy acid is defined herein as any acid comprising an SO x moiety; further the sulfoxy moiety is herein defined as any SO x moiety. It is most preferred that the sulfoxy acid in this instant invention be H 2 SO 4 . While the market for H 2 SO 4 and H 2 SO 3 is very competitive, the formation of H 2 SO 4 and/or H 2 SO 3 from S, air and H 2 O or S, O 2 and H 2 O is very exothermic. There are two processes known to manufacture H 2 SO 4 and H 2 SO 3 , the sulfuric acid condensation (SAC) and the sulfuric acid contact process (SACP), both are herein referred to as SAR, and are an embodiment in this instant invention, with the SACP preferred. The SACP produces H 2 SO 4 and/or H 2 SO 3 from S, H 2 O and air or O 2 (with one stage of reaction requiring a catalyst, preferably vanadium oxide, V 2 O 5 ). Every mole of about anhydrous H 2 SO 4 produced from S, H 2 O, and air or O 2 also produces approximately 126 kcal of energy. This valuable energy is preferably used to produce steam for at least one selected from a list consisting of: the purification of bauxite, heating of the metal polymer reactor (MPR, which can used to manufacture PAC(s) as well as MP(s)), heating of an HAR and/or HAR product distillation, reducing the H 2 O content of by-product metal sulfate, sulfite or bisulfite salts with air evaporative dehydration, electricity generation to operate the EU and any combination therein. The SACP is summarized by:
[0066] 1) S+O 2 →SO 2 +70,944 cal.
[0067] 2) SO 2 +O 2 →SO 3 +23,506 cal. (400° F. (204° C.) with catalyst, preferably V 2 O 5 )
[0068] 3) SO 3 +H 2 SO 4 →H 2 S 2 O 7 (oleum); and
[0069] 4) H 2 S 2 O 7 +H 2 O→H 2 SO 4 +20,820 cal.
[0000] (SO 3 and H 2 SO 4 to form oleum can be eliminated; however, SO 3 +H 2 O→H 2 SO 4 is a slow reaction.)
[0070] Sulfurous acid, H 2 SO 3 , is formed by reacting SO 2 , from the first reaction, with H 2 O.
[0071] It is preferred to obtain sodium sulfite by reacting SO 2 , from the first reaction, in an aqueous solution of sodium hydroxide. Further, it is an embodiment to form a metal sulfite by reacting SO 2 , from the first reaction, in an aqueous solution of metal hydroxide or a metal sulfite with H 2 SO 3 .
[0072] It is preferred to obtain sodium bisulfite by the reaction of SO 2 , from the first reaction, in an aqueous solution of sodium carbonate; and to from a metal bisulfite by the reaction of SO 2 , from the first reaction, in an aqueous solution of said metal carbonate.
[0073] In addition to the electrical and steam energy economics of H 2 SO 4 and/or H 2 SO 3 production, on-site production of H 2 SO 4 and/or H 2 SO 3 eliminates the transportation and storage of H 2 SO 4 and/or H 2 SO 3 . As discussed previously, H 2 SO 4 and/or H 2 SO 3 are hazardous chemicals that must be stored in appropriate tankage, wherein the vapors must be controlled. Therefore, it is preferred that H 2 SO 4 and/or H 2 SO 3 produced for the HAR have minimal volume storage. It is a most preferred embodiment to produce H 2 SO 4 and/or H 2 SO 3 from the SACP; and then, react said “hot” H 2 SO 4 and/or H 2 SO 3 with a metal halide in the HAR, thereby utilizing the H 2 SO 4 and/or H 2 SO 3 energy to distill the halide acid and/or reduce the water in produced metal sulfoxy salt.
[0074] It is preferred that said SACP be of design, construction and operation as is known in the art.
[0000] Halogen Acid Reactor—HAR
[0075] In the HAR, at least one of the about anhydrous salt and brine is reacted with a sulfoxy acid, preferably H 2 SO 4 and/or H 2 SO 3 and most preferably H 2 SO 4 , to form the associated halide acid, which in the case of sodium chloride is HCl, and the associated byproduct metal sulfoxy salt, which in the case of sodium chloride is a sodium sulfoxy salt, wherein said sulfoxy moiety in said metal sulfoxy salt is preferably at least one selected from a list consisting of: sulfate, bisulfate, sulfite, bisulfite and any combination therein. It is most preferred that said metal comprise sodium; it is preferred that said metal comprise a group IA or group IIA metal, while it is an embodiment that the metal comprise at least one selected from a group consisting of: ammonium, a Group IA metal, a Group IIA metal, a Group IIIB metal, a Group VIII metal, a Group 1B metal, a Group IIB metal, a Group IIIA metal, sodium, calcium, potassium, magnesium, aluminum, copper and any combination therein.
[0076] The boiling point of about anhydrous H 2 SO 4 , Na 2 SO 4 and NaCl at atmospheric pressure is approximately 340, N.B. and 1413, ° C. (644, N.B. and 2575° F.) respectively, while the boiling point of about anhydrous HCl at atmospheric pressure is approximately −85° C. (185° F.), leaving separation of the byproduct metal salt from the halide acid rather easily performed. Distillation, or separation, of the resulting anhydrous and/or aqueous halide acid solution permits the capability of directly controlling the aqueous halide acid concentration by concentration of the salt in the brine and/or by addition of water to said halide acid, which is preferably performed via an eductor and/or a compressor, wherein said eductor moves said halide acid via a stream of water and said compressor moves and/or pressurizes said halide acid. It is a preferred embodiment that said eductor move said halide acid via a stream of aqueous halide acid. It is a preferred embodiment that said compressor move said halide acid via a stream of about anhydrous halide acid. It is an embodiment that said compressor move said halide acid via a stream of aqueous halide acid.
[0077] An embodiment is to perform in the HAR reaction of a metal halide salt with a sulfoxy acid, preferably H 2 SO 4 , as said sulfoxy acid contains heat (measured as temperature) from the SAR process. A preferred embodiment is to perform the reaction of a metal halide salt in the HAR with a sulfoxy acid, preferably H 2 SO 4 and/or H 2 SO 3 , as said sulfoxy acid contains heat from said SAR process at a temperature of between about 0 and about 600° C., thereby providing said heat to create hot water and/or steam energy via heat transfer from the HAR via a water jacket on the HAR. A most preferred embodiment to perform in the HAR reaction of a metal halide salt with sulfoxy acid, preferably H 2 SO 4 , as said sulfoxy acid contains at least partially the heat from formation of at least one selected from a list consisting of: SO 2 , SO 3 , oleum, H 2 SO 4 , H 2 SO 3 and any combination therein, wherein the temperature of said reaction in said HAR is controlled by a water and/or steam jacket between about 0 and 600° C. It is preferred that said temperature in said HAR be between about 100 and 300° F. (38-149 0 C) to form a bi-sulfate or a bi-sulfite salt in said HAR. It is preferred that said temperature in said HAR be between about 300 and about 600° F. to form a sulfate or a sulfite salt in said HAR. A most preferred embodiment is to utilize said water and/or steam energy from the jacket of said HAR to heat at least one selected from a list consisting of: the formation of a metal hypohalite, the formation of a polynucleate metal compound, reducing the water in a metal sulfoxy salt to at least one of the salts: anhydrous, hydrate, di-hydrate, and any combination therein.
[0078] It is an embodiment to perform about anhydrous and/or aqueous halide acid distillation and/or separation from sulfoxy acid and/or metal sulfoxy salt under the pressure condition of at least one of: atmospheric, positive gage, vacuum and any combination therein. It is preferred that the time/temperature relationship of said halide acid or halide acid solution be managed to decompose any halite ions to halide ions (approximately 60° C. (142° F.) is required). The resulting byproduct, a sulfoxy salt, preferably of the sulfate, bisulfate, sulfite and/or bisulfite moiety, may be purified by reacting with any metal hydroxide or caustic to a desired pH, thereby purifying said byproduct metal sulfoxy salt while creating heat to the reaction of said metal halide salt with said sulfoxy acid. It is most preferred that said byproduct metal sulfoxy salt be pH adjusted with NaOH. It is preferred that said byproduct metal sulfoxy salt be pH adjusted with a metal hydroxide, wherein the metal in said metal hydroxide corresponds to the metal in said byproduct metal sulfoxy salt. It is most preferred to dehydrate said byproduct metal sulfoxy salt to a powder for sale. It is preferred to sell said byproduct metal sulfoxy salt as a hydrate. It is preferred to sell said byproduct metal sulfoxy salt as a cake. It is an embodiment to sell the byproduct metal sulfoxy salt in solution.
[0079] While the reaction to form said sulfoxy acid is exothermic, as depicted in reaction 1, the reaction to form said metal sulfate or sulfite salt is endothermic, as depicted by reaction 3; similar energies are required for the reaction of any metal halide salt with a sulfoxy acid, preferably sulfuric acid, to form a metal sulfate salt. It is therefore preferred to manufacture a metal bi-sulfate or bi-sulfite salt as is depicted in reaction number 4, thereby reducing the required energy for formation of a halide acid, while still providing a metal bi-sulfate salt, albeit in a form containing hydrogen.
[0080] It is an embodiment to recover at least a portion of the energy of formation of said metal sulfoxy salt and water from the reaction of a metal hydroxide with said sulfoxy acid, wherein said energy is used to heat said reaction of said metal halide with said sulfoxy acid, as depicted in reactions 13 and 14. It is a preferred embodiment to use H 2 generated in an electrolysis unit (EU), as described herein, or use H 2 generated in the formation of a metal hypohalite, as described herein, to heat said reaction of said metal halide salt with said sulfoxy acid to form the desired metal sulfoxy salt in said HAR. It is a preferred embodiment to use natural gas to heat said reaction of said metal halide salt with said sulfoxy acid to form the desired metal sulfoxy salt in said HAR.
[0081] As depicted in FIG. 10 , it is an embodiment that said HAR comprise a mixing/reaction section, which is preferably of an extruder/auger-type design. It is preferred that said HAR comprise at least one auger and/or extruder, wherein said metal halide salt is added to one end of said auger and/or extruder, wherein said sulfoxy acid is reacted with said metal halide salt, wherein the resultant halide acid is allowed to leave said auger and/or extruder from at least one vent. It is most preferred that said HAR comprise at least one auger and/or extruder, wherein said metal halide salt is added to one end of said auger and/or extruder, wherein said sulfoxy acid reacts with said metal sulfoxy salt, wherein the resultant halide acid is allowed to leave said auger and/or extruder from at least one vent, and wherein a metal hydroxide or a metal oxide is added to said auger and/or extruder in order to react said metal hydroxide or metal oxide with any remaining sulfoxy acid in said auger and/or extruder, such that a metal sulfoxy salt is formed with water. It is most preferred that said HAR comprise at least one auger and/or extruder, wherein said metal halide salt is added to one end of said auger and/or extruder, wherein said sulfoxy acid reacts with said metal halide salt, wherein the resultant halide acid is allowed to leave said auger and/or extruder from at least one vent, wherein a metal hydroxide or a metal oxide is added to said auger and/or extruder in order to react said metal hydroxide or metal oxide with any remaining sulfoxy acid in said auger and/or extruder to form a metal sulfoxy salt and water, wherein said water is allowed to leave said auger and/or extruder via at least one vent. To reducing the water in said metal sulfoxy salt, it is preferred that said auger and/or extruder have an operating temperature of at least approximately 140° F. (60° C.) or greater after the addition of any metal hydroxide. To reducing the water in said metal sulfoxy salt, it is most preferred that said auger and/or extruder have an operating temperature of at least approximately 212° F. (100° C.) or greater after the addition of any metal hydroxide. To maintain a reaction temperature in said auger and/or extruder it is preferred that said auger and/or extruder comprise a water jacket.
[0082] It is most preferred that said metal halide salt be added to said HAR in about anhydrous form. It is an embodiment that said metal halide salt is added to said HAR in aqueous form.
[0000] EU
[0083] It is preferred to prepare at least one disinfectant or oxidant, wherein said disinfectant or oxidant is formed by electrolysis, wherein the electricity for said electrolysis is created in a generator turned by a steam turbine, wherein said steam turbine is turned by steam energy, and wherein the steam energy to turn said steam turbine is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0084] It is preferred to produce in an EU at least one selected from a list consisting of: a metal hypohalite from a metal halide salt solution, a metal halite from a metal halide salt, a metal halate from a metal halide salt, a halide acid from a metal halide salt, O 2 from H 2 O, O 3 from O 2 , H 2 from H 2 O, H 2 O 2 from H 2 SO 4 via H 2 S 2 O 8 and H 2 O, and any combination therein, wherein at least a portion of the EU electrical energy is created by a generator, wherein the generator is turned by a steam turbine, and wherein the steam turbine is turned by steam energy obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0085] It is preferred to react said SO 2 with at least one selected from a list consisting of: a metal hydroxide to from a metal sulfite, a metal carbonate to form a metal bi-sulfite, a metal halate and H 2 SO 4 to form the corresponding halogen dioxide, and any combination therein.
[0086] It is preferred to use at least a portion of said H 2 in at least one of a: combustion engine to turn a generator to generate electricity, fuel cell to generate electricity, and heat the reaction between a metal halide salt with a sulfoxy acid. It is preferred to use at least a portion of said electricity generated by said H 2 via a combustion engine or a fuel cell to perform electrolysis in said EU.
[0087] It is most preferred that the halogen of said halide, hypohalite, halite or halate comprise chlorine or bromine. It is an embodiment that said metal halide solution comprises a waste catalyst or waste brine. It is an embodiment to use at least a portion of said H 2 to heat an HAR to form a metal sulfoxy salt.
[0088] If the EU is used to produce a halide acid, the halide acid from the EU is preferably heated: immediately after the EU, within the EU, during AHS formation, during Metal Acid Solution (MAS) formation, and any combination therein so that the halite ions are decomposed into halide ions by using available energy from at least one selected from a list consisting of: AHS formation, MAS formation, EU heat energy, and any combination therein.
[0089] It is most preferred to produce in the EU a chlorine moiety comprising at least one selected from a list consisting of: chlorine gas, hydrochloric acid, hypochlorite, chlorite and chlorate, and any combination therein, wherein at least a portion of the electrical energy for the EU is obtained from steam energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O and any combination therein.
[0090] It is preferred that halide acid production, from either the EU or the HAR be employed for the production of the associated halide or halogen gas, halide acid, hypohalite, halite or halate. It is preferred that a waste brine used in the EU.
[0091] Metal hydroxides, while a potential by-product of the EU, are a preferred material to be used in at least one selected from a list consisting of: the preparation of alumina, the production of a hypohalite, the production of a halite, the production of a halate, the production of a halogen dioxide, the scrubbing of a halide acid gas released from any of the processes in the instant invention, pH control applications that include those in the water treatment industry and pH polishing of the by-product metal sulfoxy, preferably sulfate, bisulfate, sulfite or bisulfite, salt formed in the HAR, and any combination therein.
[0092] An embodiment is to utilize any metal halide salt in the EU, wherein the associated acid product is the associated halide acid and the associated caustic product is the associated metal hydroxide. Of all the available metals to be incorporated in the metal halides to be used in the EU and the HAR, it is preferred that said metal comprise at least one selected from a list consisting of: sodium, potassium, magnesium, calcium and any combination therein.
[0093] A most preferred embodiment is to use any metal halide salt in the EU, wherein the associated product is an oxidation product of the halide, such as a halide diatom, hypohalite, halite or halate, wherein said halide diatom, hypohalite, halite or halate can comprise any halogen from the periodic table. A preferred embodiment is to manufacture a halogen dioxide, wherein the EU forms at least one selected from a list consisting of: metal halite, metal halate, halide acid, and any combination therein, wherein said halogen dioxide is formed via at least one of said manufactured: metal halite, metal halate, halide acid, SO 2 , H 2 SO 4 , and any combination therein. A most preferred embodiment is to manufacture ClO 2 , wherein the EU forms a metal chlorite and/or chlorate and wherein ClO 2 is formed via said manufactured chlorite and/or chlorate. A most preferred embodiment is to manufacture ClO 2 , wherein the EU forms a chlorite and/or a chlorate, and wherein ClO 2 is formed via said manufactured chlorite and/or chlorate with said HCl manufactured by the HAR, as said formation of ClO 2 , as well as chlorate and/or chlorite. A most preferred embodiment is to manufacture ClO 2 , wherein the EU forms a chlorite and/or a chlorate along with a hypochlorite, and wherein ClO 2 is formed with at least one of said manufactured chlorite, chlorate and hypochlorite with said HCl manufactured by the HAR. A most preferred embodiment is to manufacture a halogen dioxide, wherein the EU is used to form a metal chlorite and/or chlorate, wherein a halide acid is formed by the HAR, and wherein said halogen dioxide is formed via at least one of said EU manufactured halite, halate and hypohalite with said halide acid manufactured by the HAR. A most preferred embodiment is to manufacture a metal halate in the EU, along with SO 2 and H 2 SO 4 in the SAP, wherein said SO 2 and H 2 SO 4 are reacted to form the corresponding halogen dioxide. A most preferred embodiment is to react said halogen dioxide with a metal hydroxide and hydrogen peroxide to manufacture a metal halate, as is known in the art.
[0094] It is preferred to manufacture in the EU a halide acid, wherein at least a portion of said halide acid is used to form at least one selected from a list consisting of the corresponding: hypohalite, halite, halate, available oxide form of said halide, said halide in the form of a dioxide, and any combination therein.
[0095] It is most preferred that the EU comprise a diaphragm construction, as is known in the art.
[0096] It is preferred that the metal(s) in said metal halide salt used in said EU comprises at least one selected from a list consisting of: ammonium, a Group IA metal, a Group IIA metal, a Group IIIB metal, a Group VIII metal, a Group 1B metal, a Group IIB metal, a Group IIIA metal, sodium, calcium, potassium, magnesium, aluminum, copper and any combination therein. It is most preferred that the metal(s) used in said EU comprise sodium.
[0000] O 2 and O 3
[0097] O 2 is preferably produced via at least one selected from a list consisting of: cryogenic distillation of air, membrane separation of air, PSA separation of air and any combination therein; all of these process and process combinations therein are herein each referred to as an air separation process (ASP).
[0098] It is preferred to prepare O 2 , wherein the formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein is used to generate steam, and wherein said steam is used to perform at least one selected from a list consisting of: turn a steam turbine to generate electricity, wherein said electricity is used in the electrolysis of H 2 O to H 2 and said O 2 ; turn a steam turbine to generate electricity, wherein said electricity is used to power an ASP; turn a steam engine, wherein said steam engine powers an ASP; and any combination therein.
[0099] It is preferred that said ASP be as is known in the art. It is preferred that at least a portion of said electricity be used to power an electrolysis unit to convert O 2 into O 3 .
[0100] It is preferred that said H 2 is at least partially used in at least one of a: combustion engine to turn a generator to generate electricity, fuel cell to generate electricity, and heat the reaction between a metal halide salt with a sulfoxy acid.
[0000] H 2 O 2
[0101] H 2 O 2 can be produced utilizing H 2 SO 4 as the catalyst. In this reaction, H 2 O 2 is formed in a two stage process, wherein the first stage H 2 S 2 O 8 and H 2 are formed by electrolysis from H 2 SO 4 . In the second stage, the H 2 S 2 O 8 from the first stage is reacted with H 2 O to form H 2 O 2 and H 2 SO 4 . The H 2 gas can be vented, stored or used as an energy source; the H 2 SO 4 can be recycled for additional production of H 2 S 2 O 8 and H 2 . The use of H 2 O 2 in water treatment and other applications has been limited due to its explosive nature creating expense in both transportation and in storage; H 2 O 2 is a much more hazardous chemical than is H 2 SO 4 and/or H 2 SO 3 to store and transport. It is most preferred to produce H 2 O 2 utilizing H 2 SO 4 from said SACP. It is preferred to produce H 2 O 2 and H 2 wherein, at least a portion of the electricity for electrolysis of H 2 O to H 2 O 2 is obtained from the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein. It is preferred to recycle at least a portion of the H 2 from H 2 O 2 electrolysis manufacture wherein, at least a portion of the electrical energy for the electrolysis of H 2 O to H 2 O 2 is obtained from the energy of combustion and/or of fuel cell conversion of said H 2 .
[0000] Halogen Dioxide and Metal Halite Formation
[0102] It is preferred to form a metal halate in the EU from an aqueous solution of the corresponding metal halide, wherein the energy of electrolysis (energy of formation) for said metal halate is at least partially created by a generator, wherein said generator is turned by stream energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O and any combination therein.
[0103] It is an embodiment to form a halogen dioxide with said metal halate formed in the EU, wherein said halate is further reacted to form said halogen dioxide from said metal halate, wherein the energy of electrolysis (energy of formation) for said metal halate is at least partially created by a generator, wherein said generator is turned by stream energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O and any combination therein.
[0104] It is an embodiment to form the available oxide form of a halogen, including a halogen dioxide, wherein said formation is performed with at least one selected from a list consisting of said corresponding: halide acid, hypohalite, halite, halate, and any combination therein, wherein at least one of said halide acid, hypohalite, halite and halate is formed in an EU, wherein the electricity of electrolysis for the EU is at least partially created by a generator, wherein said generator is turned by stream energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , said H 2 SO 4 from oleum and H 2 O and any combination therein.
[0105] It is an embodiment to react said metal halate to form the corresponding halogen dioxide. It is preferred to react said metal halate to form the corresponding halogen dioxide according to at least one of reactions 18, 19, 20 or 21 to form the corresponding halogen dioxide, as is known in the art. It is most preferred to react said metal halate to form the corresponding halogen dioxide according to reaction 19.
[0106] It is most preferred to perform reaction 19, wherein at least one of said H 2 SO 4 can be a sulfoxy acid in general, wherein said sulfoxy acid and said SO 2 is obtained from an SAR, wherein the electrical energy of electrolysis to form said metal halate is obtained from steam energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O and any combination therein.
[0107] It is preferred to perform reaction 21, wherein said H 2 SO 4 , which can be a sulfoxy acid in general, is obtained from an SAR; it is most preferred that said H 2 O 2 is at least partially obtained by the electrolysis of H 2 SO 4 via H 2 S 2 O 8 and H 2 O, wherein the electrical energy of electrolysis to form said metal halate is obtained from steam energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O and any combination therein.
[0108] It is preferred to use at least a portion of said steam energy to at least partially perform at least one selected from a list consisting of: refine bauxite to alumina, heat said aqueous reaction of a metal halide solution with at least one metal, evaporate H 2 O from a metal sulfoxy salt, degrade a halite to a halide, heat S, turn a steam turbine which turns a generator to create electricity, heat the reaction of a metal hydroxide and a halide acid to form a metal hypohalite, and any combination therein.
[0109] It is preferred then to react said halogen dioxide to form a metal halite, as is known in the art. It is most preferred then to react said halogen dioxide according to reaction 25 to form the corresponding metal halite. It is most preferred then to react said halogen dioxide according to reaction 25 to form the corresponding metal halite, wherein said H 2 O 2 is formed by the electrolysis of water, wherein the electrical energy of said electrolysis to form said H 2 O 2 is obtained from steam energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein. It is most preferred to then react said halogen dioxide according to reaction 25 to form the corresponding metal halite, wherein said NaOH can be any metal hydroxide, yet is most preferably sodium hydroxide, wherein said metal hydroxide is formed by at least one of: electrolysis of the corresponding metal halide, the reaction of a metal sulfoxy salt with a moiety of calcium, wherein said moiety of calcium is preferably calcium oxide or calcium hydroxide, wherein said metal sulfoxy salt is obtain from an HAR (as presented herein), and wherein the reaction within said HAR to form said metal sulfoxy salt comprises a reaction between the corresponding metal halide with the corresponding sulfoxy acid. It is most preferred that said halogen comprise chlorine and said halate comprise chlorate. It is most preferred that said metal comprise sodium.
[0110] Once transported to the location of use, it is an embodiment to then form a halogen dioxide from said metal halite, as is known in the art. Once transported to the location of use, it is preferred to then form a halogen dioxide from said metal halite according to reaction 26. Once transported to the location of use, it is most preferred to then form a halogen dioxide from said metal halite according to reaction 26, wherein said HCl can be any halogen acid, yet is most preferably hydrochloric acid, wherein said halogen acid is manufactured by at least one of: the formation of said halogen acid by electrolysis of the corresponding metal halide salt, wherein the electrical energy of electrolysis to form said H 2 O 2 according to reaction 21 is obtained from steam energy, and wherein said steam energy is obtained from the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O and any combination therein; and the formation of said halide acid in an HAR is obtained from the reaction of the corresponding metal halide salt with a sulfoxy acid.
[0111] In the formation of said metal halite, it is an embodiment of the instant invention to react chloride ions, preferably having a concentration of from about 1 M to about 5 M, with chlorate ions, preferably having a concentration of from about 0.1 M to about 7 M, in an aqueous acid reaction medium having an acid normality of from about 0.05 N to about 5 N. As sodium chloride precipitates in the system, it may be separated by means of a filter or recycled in a solution or slurry to the EU. A gaseous product mixture comprising a halogen dioxide, preferably chlorine dioxide, may be absorbed in any suitable aqueous medium. However, it is beneficial for the absorption medium to preferably absorb said halogen dioxide, preferably chlorine dioxide, and less preferably absorb the halogen, which would be preferably chlorine. An example of such a medium is the corresponding dilute halogen acid, preferably hydrochloric acid. A suitable reagent able to destroy traces of halogen, which is preferably chlorine, is hydrogen peroxide, which may optionally be added to the absorption medium, if desired.
[0112] In order to transfer the absorbed halogen dioxide, preferably chlorine dioxide, from the absorption medium to the halite, preferably chlorite, formation reactor, any suitable gas stripping method may be employed. The stripping of halogen, preferably chlorine, dioxide may be carried out with an inert gas or gas mixture, such as air or nitrogen. If air is used in the halogen, preferably chlorine, dioxide stripping, it is preferred to purify the air from traces of carbon dioxide, by using, for example, a caustic scrubber. Hydrogen peroxide can optionally be added to the system prior to effecting stripping.
[0113] It is preferred to transfer the gaseous product mixture formed in the halogen, preferably chlorine, dioxide generator directly to the chlorite formation reactor without the intermediate step of absorption and/or stripping. Instead of absorption/stripping, gas transfer membranes can be employed, as in known in the art, thereby allowing the transfer of halogen, preferably chlorine, dioxide in the absence of any air addition.
[0114] It is an embodiment to modify the halogen dioxide generator by addition of a supplementary reducing agent, such as hydrogen peroxide, as is known in the art.
[0115] It is also an embodiment to improve the performance of the halogen-dioxide generator by using any suitable catalytically-active agent containing elements, such as silver, manganese, palladium, chromium, vanadium or a combination thereof.
[0116] While it is known in the art to use the chloride ion as an inexpensive reducing agent, the reaction of the chloride ion with the chlorate ion necessarily results in the formation of some chlorine, e.g.:
ClO 3 − +Cl − +2H + →ClO 2 +½Cl 2 +H 2 O
which may negatively affect purity of the final halite, preferably chlorite, product while increasing use of hydrogen peroxide. It is, therefore, a preferred embodiment to generate said halogen dioxide, preferably chlorine dioxide, by reaction 26.
[0117] Reaction 26 can be carried out in a very broad acid normality range of from about 2 N to about 14 N, preferably from about 6 N to about 12 N. The optimum chlorate ion concentration is dependent on acid normality in the reaction medium and can vary from about 0.1 M to saturation, and preferably from about 0.5 M to about 3.5 M. Operation at higher acidities is typically associated with a lower chlorate concentration in the reaction medium. The gaseous product mixture comprising chlorine dioxide and water vapor can be used directly in the chlorite formation reactor without the intermediate step of recovery of chlorine dioxide solution, i.e., by omitting the absorption and stripping stages.
[0118] Such an operation leads to significant cost savings due to the elimination of certain parts of the conventional chlorine dioxide generating system, such as condenser, absorption tower and stripping tower.
[0119] The co-produced oxygen gas can be used along with the water vapor for the dilution of gaseous halogen, preferably chlorine, dioxide to safe concentration levels. By adjusting the halogen, preferably chlorine, dioxide to water vapor ratio to meet the requirements of the halite, preferably chlorite, formation reactor, the water balance of the overall system is improved. The relative ratio of halogen, preferably chlorine, dioxide and water vapor in the gaseous mixture entering the halite, preferably chlorite, formation reactor affects the concentration of metal halite, preferably group IA or group IIA metal chlorite, in the final product aqueous solution. Therefore, there may still be a need to condense at least some of the water vapor.
[0120] It is preferred to integrate the halogen dioxide, preferably chlorine dioxide, generator with a methanol based halogen, preferably chlorine, dioxide generating system, as is known in the art, wherein the acidic, sulfate and/or bisulfate containing effluent or slurry formed in the hydrogen peroxide based generator is cascaded to the methanol based generator. This integration eliminates the requirement for the filtration step following the hydrogen peroxide based generator.
[0121] The above described cascade of two halogen, preferably chlorine, dioxide generators offers several advantages. For example, it is possible to add a small amount of sodium halide, preferably chloride, typically about 0.5 to about 1.0 wt. % based on the halate, preferably chlorate, to the hydrogen peroxide based generator. Such an addition of halide, preferably chloride, may have little or no impact on the chlorine dioxide purity resulting from the hydrogen peroxide based process, while such addition may be beneficial with regard to the production rate and efficiency. The presence of hydrogen peroxide should effectively prevent halide, preferably chlorine, from being generated in the halogen, preferably chlorine, dioxide generating process.
[0122] It is an embodiment to recover the metal sulfate and/or bisulfate, preferably sodium sulfate and/or sodium bisulfate, following the hydrogen peroxide-based generator by reaction with a moiety of calcium, preferably CaOH to form the corresponding metal hydroxide, preferably sodium hydroxide, and calcium sulfate, calcium sulfate ½ hydrate and calcium sulfate di-hydrate (gypsum).
[0123] It is an embodiment to recover the metal sulfate and/or bisulfate, most preferably sodium sulfate and/or sodium bisulfate, following the conversion of the halogen dioxide to a metal halate by reacting said metal sulfate and/or bisulfate with a moiety of calcium, preferably CaOH, to form the corresponding metal hydroxide, most preferably at least one of sodium, and calcium sulfate, calcium sulfate ½ hydrate and calcium sulfate di-hydrate (gypsum). It is preferred that the metal(s) in said metal sulfate and/or bisulfate comprise a group IA or group IIA metal.
[0124] Any possible halogen, preferably chloride, input to the peroxide-based process may ultimately exit the system with the halogen, preferably chlorine, dioxide produced in the methanol-based halogen, preferably chlorine, dioxide generator. However, the impact on product purity should not be significant, especially when production capacity of the latter process is much higher than that of the peroxide-based process.
[0125] The combination of two halogen, preferably chlorine, dioxide generators permits all or part of the halogen dioxide containing condensate originating from the peroxide-based process to be forwarded to the halogen, preferably chlorine, dioxide absorption system associated with the methanol-based process. This embodiment is particularly beneficial since the need to remove the halogen, preferably chlorine, dioxide from the condensate is eliminated.
[0126] Any suitable catalyst can be added to the peroxide-based halogen, preferably chlorine, dioxide generating process, if desired. It is understood that the halate, preferably chlorate, ions required for halogen, preferably chlorine, dioxide generation can be supplied not only by a group IA or IIA metal halate, preferably sodium chlorate, but also by halic, preferably chloric, acid or mixtures thereof with said group IA or IIA metal halate, preferably chlorate. While the most preferred acid used in the process of the instant invention is sulfuric acid, any other strong mineral acid, such as perchloric acid, chloric acid, a halic acid, nitric acid, phosphoric acid, hydrochloric acid or the mixtures thereof can be employed.
[0127] While any suitable reactor design can be used in the halogen dioxide formation step, a packed tower reactor is most preferred, wherein the halogen dioxide leaves the top of the tower after reacting with an aqueous phase of the metal halate, along with the other required reactants, as required by the method employed. It is an embodiment to form the halogen dioxide in a stirred vessel while capturing the halogen dioxide gas above; however, such a scenario without a packed tower may lead to loss of reactants and/or halide ions with the halogen dioxide.
[0128] While any suitable reactor design can be used in the chlorite formation step, a packed tower reactor is most preferred, wherein the chlorite solution is recirculated and enters the reactor from the top. Hydrogen peroxide is added to the recirculation loop at a point prior to solution entry to the reactor. Sodium hydroxide and, optionally, dilution water is added at the bottom of the recirculation loop. The addition point of halogen, preferably chlorine, dioxide diluted with at least one inert gas, such as air, water vapor and nitrogen, is at the bottom of the reactor. The gas is passed counter-currently to the halite, preferably chlorite, solution.
[0129] The pH of the reaction medium is maintained generally in the range of about 11.8 to about 13.0, preferably about 12.0 to about 12.6. The hydrogen peroxide excess is preferably maintained using a potentiometric (ORP) measurement. The ORP values, which are pH dependent, are generally maintained in the range of between about −30 to about −200 mV vs. Ag/AgCl, preferably about −40 to about −90 mV vs. Ag/AgCl.
[0000] Halide Acid—Metal Hydroxide—Metal Sulfoxy Salt Formation
[0130] In the instant invention, both the halide acid and its associated metal hydroxide or metal oxide may be produced from the metal halide salt by electrolysis in the aforementioned EU. While sodium chloride is preferred, any metal halide salt may be used to form the associated halide acid and the associated metal hydroxide, preferably in solution. However, the halide acid is more economically formed by the reaction of the metal halide salt with a sulfoxy acid, preferably H 2 SO 4 , in an HAR. This reaction produces the halide acid, along with the corresponding metal salt, wherein the anion for said salt is a sulfoxy molecule, preferably at least one selected from a list consisting of a: sulfite, bisulfite, sulfate, bisulfate and any combination therein.
[0131] A preferred embodiment utilizes about anhydrous or aqueous sodium chloride in the EU as a metal halide salt, wherein the associated acid product is HCl and the associated caustic product is sodium hydroxide (NaOH). A more economical and most preferred process embodiment utilizes about anhydrous sodium chloride as a metal halide salt in said HAR, wherein the associated acid product is HCl, preferably HCl(g), and the associated byproduct salt is sodium in combination with at least one selected from a list consisting of a: sulfate, bisulfate, sulfite, bisulfite and any combination therein.
[0132] A preferred process embodiment utilizes about anhydrous or aqueous calcium chloride as the metal halide salt in an EU, wherein the associated acid product is HCl and the associated caustic product is calcium hydroxide. A more economical and most preferred process embodiment utilizes about anhydrous calcium chloride as a metal halide salt in said HAR, wherein the associated acid product is HCl and the associated byproduct salt is calcium in combination with at least one selected from a list consisting of a: sulfate, bisulfate, sulfite, bisulfite and any combination therein.
[0133] A preferred process embodiment utilizes about anhydrous or aqueous potassium chloride as a metal halide in the EU, wherein the associated acid product is HCl and the associated caustic product is potassium hydroxide. A more economical and most preferred process embodiment utilizes about anhydrous potassium chloride as a metal halide in said HAR, wherein the associated acid product is HCl and the associated byproduct salt is potassium in combination with at least one selected from a list consisting of: sulfate, bisulfate, sulfite, bisulfite and any combination therein.
[0134] A preferred process embodiment utilizes about anhydrous or aqueous magnesium chloride as a metal halide in the EU, wherein the associated acid product is HCl and the associated caustic product is magnesium hydroxide. A more economical and most preferred process embodiment utilizes about anhydrous magnesium chloride as a metal halide in said HAR, wherein the associated acid product is HCl and the associated byproduct salt is magnesium in combination with at least one selected from a list consisting of: sulfate, bisulfate, sulfite, bisulfite and any combination therein.
[0135] As can be readily seen herein, the metal halide salt in the EU or in the HAR can easily be any metal in combination with any halide. It is preferred that the metal comprise at least one selected from a list comprising: Group IA metal, Group IIA metal, Group IIIB metal, Group VIII metal, Group 1B metal, Group IIB metal, Group IIA metal and any combination therein. It is most preferred that the metal comprise at least one selected from a list consisting of: sodium, calcium, potassium, magnesium, aluminum, copper and any combination therein.
[0000] Bleach, Metal Hydroxide and Gypsum Formation
[0136] In the instant invention, it is preferred to utilize at least a portion of the electricity obtained from a generator turned by a steam turbine, wherein said steam turbine is turned by steam energy, and wherein said steam energy is obtained from the formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , said H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein in an electrolysis unit to form at least one selected from a list consisting of: a metal halate from an anhydrous or hydrous metal halide salt, a metal hypohalite from an anhydrous or hydrous metal halide salt, a metal halite from an anhydrous or hydrous metal halide salt, O 2 from H 2 O, H 2 from H 2 O, H 2 O 2 from the electrolysis of H 2 SO 4 to H 2 S 2 O 8 followed by the reaction of said H 2 S 2 O 8 with H 2 O, a metal hydroxide from an anhydrous or hydrous metal halide salt, a halogen acid from an anhydrous or hydrous metal halide salt and any combination therein.
[0137] It is preferred to manufacture a metal hypohalite by the reaction of a metal hydroxide with a halide acid, wherein said halide acid is manufactured in an HAR from the reaction of a metal halide salt with a sulfoxy acid, thereby forming the corresponding metal sulfoxy salt along with the corresponding halide acid, and wherein said metal sulfoxy salt is then reacted with a Group IIA metal hydroxide to form said metal hydroxide along with the corresponding Group IIA sulfoxy salt in either an aqueous or hydrated form. It is most preferred that the unit forming said metal hypohalite by the reaction of a metal hydroxide with a halide acid, bleach reactor, comprise at least one selected form a list consisting of: continuous stirred tank reaction, batch stirred tank reaction, plug flow reaction and any combination therein.
[0138] It is preferred to manufacture a metal hypohalite by the reaction of a metal hydroxide with a halogen acid, wherein said halogen acid is manufactured in an electrolysis unit, wherein the electrical energy for electrolysis in said electrolysis unit is generated by the energy of formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, said H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0139] It is preferred to prepare (or manufacture) a metal hydroxide in aqueous solution, wherein a metal sulfoxy salt is reacted with a Group IIA metal hydroxide, thereby creating a mixture comprising a metal hydroxide, water and a Group IIA metal sulfoxy salt, wherein said Group IIA metal sulfoxy salt comprises at least one selected from a list consisting of: sulfate, sulfate ½ hydrate, sulfate di-hydrate, sulfite, hydrogen sulfite, sulfite di-hydrate and any combination therein, and wherein said mixture is separated, thereby forming an aqueous solution comprising said metal hydroxide, and a moist solid phase comprising said Group IIA metal sulfoxy salt, said metal hydroxide and water.
[0140] It is preferred to perform a separation of the aforementioned metal hydroxide in aqueous solution from said moist solid phase in order to react said metal hydroxide aqueous solution with said halogen acid to form said metal hypohalite aqueous solution. It has been found that due to the specific gravity difference between an aqueous solution of a Group IA metal hydroxide and a Group IIA metal sulfoxy salt (or any group IIA metal sulfoxy salt vs. a metal of lower density) in combination with the inherent insolubility of a Group IIA sulfoxy salt (preferably calcium) with the inherent solubility of a Group IA or metal hydroxide (again sodium is the most preferred metal), it is preferred to perform said separation by gravity settling. It is preferred that said gravity settling be enhanced by a vibration-type device placed upon and/or within the vessel of separation, thereby facilitating said separation of said group IIA sulfoxy salt moiety, which is in the form of at least one selected from a list consisting of: sulfoxy, sulfoxy hydrate, sulfoxy di-hydrate and any combination therein. It is most preferred that said moist solid phase from said separation comprise at least one selected from a list consisting of: calcium sulfate, calcium sulfate ½ hydrate, calcium sulfate di-hydrate, calcium sulfite, calcium hydrogen sulfite, calcium sulfite di-hydrate and any combination therein. It is preferred that said moist solid phase from said separation be about 10 to 85 percent solids. It is most preferred that said solid phase from said separation be about 60 to 90 percent solids. It is most preferred that said separation vessel comprise near the bottom portion of said separation vessel at least a portion of a conical shape, wherein the pointed portion of said conical shape point down such that said separated solid phase pass through an opening in said pointed portion of said conical shape. While said conical shape can be of circular construction, thereby having no corners, it is an embodiment said conical shape be of a construction which comprises at least three corners. It is preferred that said conical shape have between three and ten corners or locations wherein a side of said conical shape meets another section of said conical shape. While said vibration-type device may enhance the liquid/solids separation of said group IA or group IIA metal hydroxide aqueous solution from said solid phase, it is preferred that said vibration-type device have the ability to limit or minimize bridging of the solid phase in the bottom of the conical section of said separation vessel.
[0141] It is most preferred to separate an aqueous solution of a metal hydroxide from said Group IIA sulfoxy salt, such that an aqueous solution is obtained comprising said metal and said hydroxide, and a moist solid phase is obtained comprising said Group IIA sulfoxy salt, said metal, said hydroxide and water. Again, the preferred metal is sodium and the preferred Group IIA metal is calcium.
[0142] It is most preferred that said separation vessel, as described previously herein be performed a number of times, wherein a subsequent separation vessel have added to it the moist solids phase from a previous separation vessel, and wherein within or prior to said subsequent separation vessel water is added to the separated moist solid from said previous separation vessel, such that the concentration is lowered of said group IA or group IIA metal hydroxide in aqueous solution. It is preferred that the water concentration within the first separation vessel be controlled by the addition of water to at least one selected from a list consisting of: water to a lime slaker, water to calcium hydroxide, water to said first separation vessel, water to a group IIA metal other than calcium, and any combination therein.
[0143] It is preferred to perform a water dilution of a moist solid phase from a separation thereby creating a mixture comprising said metal, water, a hydroxide and a moist solid, wherein said moist solid phase comprises a Group IIA metal with at least one selected form a of list consisting of: sulfate, sulfate ½ hydrate, sulfate di-hydrate, sulfite, hydrogen sulfite, sulfite di-hydrate and any combination therein, wherein the concentration of said metal hydroxide in said mixture is less than previous, and wherein said aqueous solution is separated from said moist solid, such that an aqueous solution is obtained comprising said metal hydroxide, and a moist solid phase is obtained comprising said Group IIA metal salt, said metal hydroxide and water.
[0144] It is most preferred that the moist solid phase from a separation vessel be transferred to a subsequent separation vessel. It is an embodiment that said transfer comprise at least one selected from a list consisting of: a screw, an auger, a conveyor, a pneumatic system, and any combination therein, as is known in the art of solids transfer.
[0145] It is most preferred that the moist solid phase from the last separation vessel, final separated moist solids, be transferred to a dryer so as to reducing the water in said moist solids. It is preferred to pH adjust said final separated solids with an acid prior to said transfer to said dryer. It is preferred that said acid for said pH adjustment of said final separated solids comprise a sulfoxy type acid. It is most preferred that said sulfoxy type acid comprise sulfuric acid.
[0146] It is preferred that said Group IIA metal hydroxide is formed by the reaction with water of: said Group IIA metal or Group IIA metal oxide or Group IIA metal hydroxide, in what is otherwise known as a slaker unit. It is most preferred that said Group IIA metal comprises calcium. It is most preferred that said Group IIA metal comprise calcium, such that said Group IIA oxide comprises calcium oxide, said Group IIA metal hydroxide comprises calcium hydroxide and said Group IIA metal sulfoxy salt comprises calcium sulfoxy salt. It is most preferred that said sulfoxy moiety comprise sulfate.
[0147] It has been learned by this instant invention that should the aqueous phase in said last separation vessel be about less than 10% of a Group IA metal hydroxide that the final separated solids will be about 90 to 98 percent of at least one selected from a list consisting of: a calcium sulfoxy salt, a calcium sulfoxy salt hydrate, a calcium sulfoxy salt dehydrate and any combination therein, herein referred to as gypsum product. (Again, calcium can be replaced with a group IIA metal.)
[0148] As the solubility of calcium hydroxide in water is about less than 2,000 mg/L, depending upon temperature, there may be situations wherein it is preferred to remove soluble calcium, or any group IIA metal, from a group IA metal hydroxide or a group IA metal hypohalite. It is a preferred embodiment to purify a group IA metal hydroxide or group IA metal hypohalite of calcium, or any group IIA metal, by adding to an aqueous solution of said group IA metal hydroxide or group IA metal hypohalite a from of carbonate or of carbon dioxide, which forms carbonate upon contact with water. Said carbonate, it is found by the instant invention, will then form calcium carbonate, or a group IIA carbonate, within said group IA metal hydroxide solution or said group IA metal hypohalite solution. Calcium carbonate, or group IIA metal carbonates, being soluble at only about 20 mg/L or less, will then form a precipitate leaving about less than 20 mg/L of calcium in solution with said group IA metal hydroxide. Said calcium carbonate is then preferably separated from said group IA metal hydroxide solution or group IA metal hypohalite by at least one selected form a list consisting of: an additional separation vessel, as described herein; filtration; gravity settling; clarification; and any combination therein. It is preferred that said calcium carbonate be dried separately or with said gypsum product.
[0000] Polynucleate Aluminum Compounds (PAC), PMC, and MP(s)
[0149] Polynucleate aluminum compounds (PAC) and polynucleate metal compounds (PMC), whether or not containing aluminum, are both referred to as metal polymers (MP(s)). MP(s) as used herein refer to polynucleate metal compositions such as aluminum chlorohydrate, aluminum hydroxychloride, aluminum hydroxyhalide, polyaluminum hydroxysulfate and polyaluminum hydroxychlorosulfate, polyaluminum hydroxyhalosulfate polyaluminum hydroxy sulfate calcium chloride, polyaluminum hydroxy sulfate calcium halide, polyaluminum hydroxychlorosulfate calcium chloride, polyaluminum hydroxychlorosulfate calcium halide, polyaluminum hydroxyphosphate chloride, polyaluminum hydroxyphosphate halide, polyaluminum hydroxy “metal” chloride and/or sulfate and/or phosphate, polyaluminum “multi-metal” hydroxy chloride and/or sulfate and/or phosphate, polyaluminum hydroxy “metal” halide and/or sulfate and/or phosphate, polyaluminum “multi-metal” hydroxy halide and/or sulfate and/or phosphate and the like, and poly metal hydroxy halide and/or sulfate and/or phosphate and the like wherein the metal is any metal that exists in the +2 or +3 valence state.
[0150] It has been shown possible by means of the instant invention to obtain the above-mentioned MP(s), whereby the raw materials can simply be: a metal halide salt; along with a metal in said MP in the form of at least one selected from a list consisting of: the base metal, hydroxide form, oxide form and any combination therein, as well as comprising a sulfoxy acid, preferably H 2 SO 4 and/or H 2 SO 3 . Moreover, recycled metal is a possibility, as compared to a refined metal oxide and/or hydroxide. Metals, other than aluminum, can be used if prepared or capable of entering their +2 or +3 valence state in their respective acid, oxide or hydroxide form. And, as a recycling measure, waste catalyst streams or waste brine streams from refineries and/or chemical plants containing aluminum halide or other metal halides can be used to manufacture MP.
[0151] It is a preferred embodiment to prepare an MP, comprising at least one metal in the +2 or the +3 valence state, wherein said polynucleate metal compound is formed by the aqueous reaction of a metal halide solution with at least one metal, wherein said metal halide solution comprises at least one metal in the +2 or +3 valence state, wherein said at least one metal is in the 0, +2 or +3 valence state, and if in the 0 valence state is capable of entering the +2 or +3 valence state, wherein said metal halide solution is formed by the aqueous reaction between said metal(s) within said metal halide solution and a halide acid, and wherein said halide acid is formed by the reaction of a metal halide salt, comprising the corresponding halide of said halide acid, with a sulfoxy acid.
[0152] It is preferred that the metal(s) in said metal halide solution or said at least one metal comprise at least one selected from a group consisting of: ammonium, a Group IIA metal, a Group IIIB metal, a Group IVB metal, a Group VB metal, a Group VIB metal, a Group VIIB metal, a Group VIII metal, a Group 1B metal, a Group IIB metal, a Group IIIA metal, and any combination therein. It is preferred that said metal in said metal halide solution comprise a group IIIA metal; it is most preferred that said metal in said metal halide salt comprise aluminum. It is preferred that said MP comprise a sulfoxy acid, most preferably H 2 SO 4 . It is preferred that the sulfoxy acid is formed by the sulfuric acid contact process.
[0153] It is preferred that at least one of: the metal in the metal halide solution is aluminum and said at least one metal is aluminum, the metal in said metal halide solution is aluminum and the at least one metal is at least one metal other than aluminum, the metal in the metal halide solution is a metal other than aluminum and the at least one metal is aluminum, and the metal in the metal halide solution and the at least one metal is a metal other than aluminum.
[0154] It is preferred that the halide in the MP comprise at least one of chlorine and bromine. It is preferred that said MP comprises at least one selected from a list consisting of: sulfate, phosphate, carbonate, silicate, nitrate and any combination therein.
[0155] MP formation is to be performed in a reaction vessel, termed a metal polymerization reactor (MPR). Said MPR can comprise at least one selected from a list consisting of a: continuous stirred tank reactor (CSTR), a batch stirred tank reactor, a pipe reactor (otherwise known as a plug flow reactor, PFR), and any combination therein, as known in the art. (If a CSTR, residence times of 1 to 4 hours may be required.) It is most preferred that said MPR have high shear mixing, as the instant invention has found high shear conditions during aqueous formation of MP(s) to minimize waste-product, gel, formation and maximize final product, MP formation. It is preferred that reactor mixing energy create a shear situation of approximately greater than 30 sec −1 . It is most preferred that reactor mixing energy create a shear situation of approximately greater than 45 sec −1 . High shear is defined in this instant invention as a mixing energy of approximately greater than 30 sec −1 . However, as is known in the art of mixing and agitation, a high shear mixing scenario can be obtained by many means, including a centrifugal pump, homogenizer, reactor agitator or any physical system which combines the aqueous reactants in a situation of high kinetic energy contact, thereby creating a situation of high Reynolds Number of about greater than about 1,000 and preferably greater than about 2,000. It is a preferred embodiment to manufacture said MP by batch in a stirred tank reactor. It is most preferred to manufacture said MP in a plug flow or pipe reactor. It has further been found in the instant invention that high shear mixing energies lengthen the shelf life of the MP by as much as 100 to 500 percent. It is theorized that this increase is obtained due to a minimization on an atomic scale of gel formation during MP formation and thereby a minimization of available sites for macro gel globules to begin formation over time.
[0156] A final MP product is prepared having a metal content, preferably comprising aluminum, of approximately 3-12 percent. A solid MP can be obtained by reducing the water in an MP, wherein a product containing approximately 12-24 percent of aluminum is obtainable, whereby spray drying or rolling can be used as the drying method. A product containing aluminum and another metal(s) can be obtained, wherein the combined aluminum/other metal(s) concentration is less than or equal to approximately 12 percent if in solution or approximately equal to or less than 24 percent if dried. A product containing at least one metal other than aluminum can be obtained, wherein the metal(s) concentration is less than or equal to approximately 12 percent if in solution or approximately equal to or less than 24 percent if dried.
[0157] There is no need to use an excess of aluminum or metal in the MPR, as with high shear mixing, the reaction has demonstrated near complete incorporation of aluminum. As is known in the art, a higher molar relationship can easily be increased by adding CaO, CaCO 3 or Ca(OH) 2 whereby a molar relationship of 1.8-1.9 can be obtained without increasing the reaction time to any considerable extent. In the case that one should want a further increase in the molar relationship OH:Al or OH:metal up to 2.5, metallic aluminum or metallic metal is to be added in the stoichiometric amount.
[0158] It is preferred to manufacture an MP containing the sulfoxy moiety by incorporating a sulfoxy acid into the MPR under a situation of high shear mixing.
[0159] It is a preferred embodiment there is no vehicular transportation of at least one selected from a list consisting of said: halide acid, metal halide solution, sulfoxy acid, and any combination therein.
[0160] It is preferred to manufacture said MP in an MPR heated with steam, as described herein, along with obtaining steam from the formation of at least one selected from a list consisting of: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein. It is further an embodiment to create electricity from the energy of said steam as described previously in this instant invention.
[0000] MAS (ACS Formation)
[0161] It is an embodiment to react at least one metal other than aluminum into the MP; said metal(s) are to be preferably acidified prior to addition to the MPR. When any metal other than aluminum is reacted in the MP, said metal(s) needs to: form either a +2 or +3 valence state in said MAS, be prepared in their respective oxide or hydroxide form in either the +2 or +3 valence state prior to addition to the MPR or be capable of entering a +2 or +3 valence state in the MPR. While more than one metal other than aluminum can be entered into the MP and an MP can be manufactured with at least one metal other than aluminum, wherein no aluminum is used, in the instant invention it is preferred to maximize the use of aluminum and minimize the use of other metals due to the availability and cost of bauxite, alumina and aluminum. For particular applications, it may be preferred to choose a metal for that particular application; examples would include zirconium for antiperspirants, copper for algae control in water systems, tin as a sacrificial metal in corrosion control applications and gold, copper or silver for conductivity applications. MAS is, therefore, defined herein as at least one metal in halide acid solution wherein said metal(s) are in the +2 or +3 valence state in concert with at least one halogen in anionic form.
[0162] MAS is formed from the aqueous reaction of a halide acid with a metal, metal salt, metal oxide or metal hydroxide, wherein said reaction with a metal, metal oxide and metal hydroxide is preferred. MAS is formed in the Metal Acid Reactor (MAS). Aluminum halide solution (AHS) is formed from the reaction of the halide acid with at least one selected from a list consisting of: bauxite, an aluminum salt, aluminum, aluminum oxide and aluminum hydroxide. The formation of MAS or AHS can occur in any vessel with agitation, such as a CSTR or a PFR. A vent scrubber is preferably to be placed on said reactor or downstream of said reactor to control emissions of hydrogen chloride gas (HCl(g)), or other halogen gas if a halogen acid other than HCl is used. A portion of the enthalpy from AHS or MAS manufacture can be utilized to decompose halite ions and/or provide heat to said MPR. AHS and/or MAS containing up to 5 percent metal, preferably aluminum, can easily be prepared. AHS and MAS are easily prepared with the appropriate halide acid reacting with the chosen metal, metal salt, metal oxide or metal hydroxide.
[0000] Alumina
[0163] The purification of bauxite to alumina creates alumina for the preparation of aluminum halide solution (AHS), wherein AHS can be formed by reacting alumina with HCl. Purified bauxite, alumina, may also be required for MP production, in the MPR, if the raw bauxite contains any other heavy metal impurities and the resultant MP is to be used in drinking water purification or another application where heavy metal purity is an issue.
[0164] It is preferred to provide steam to a portion of the metal hydroxide solution in order to perform the “Bayer” Refining Process (BRP), which can preferably proceed adjacent to the SACP and/or the EU, thereby utilizing the enthalpy of sulfoxy acid formation and/or electrolysis to minimize steam required in the BRP. While the BRP is most preferably used to purify bauxite, an alternate preferred method would be to utilize recycled aluminum metal, where the metal is purified in the BRP alone or with bauxite. If recycled aluminum is used, a portion of the halide acid production can be used to assist in the purification of the recycled aluminum or converting the aluminum to the associated aluminum halide acid, which is preferably aluminum chloride solution, ACS. A side stream of the hydroxide solution is preferably available to the MPR to assist in managing either the reactor pH or final MP basicity, as needed. Portions of the metal hydroxide solution are preferably sent to the halide acid gas scrubbing system to pH-neutralize the liquid effluent and/or to the by-product metal stream to pH balance the final by-product metal sulfate, sulfite or bisulfite salt.
[0165] Aluminum is provided for the MP or AHS with at least one selected from a list comprising: bauxite, alumina, aluminum hydroxide, aluminum metal and any combination therein. The aluminum metal can be refined or recycled. Should bauxite be used and NaOH or MOH from the EU be provided to refine the bauxite, the waste minerals from bauxite refining have many market uses, such as soils stabilization. It is most preferred to use alumina, aluminum or purified recycled aluminum in the preparation of AHS and MP because the acidification of bauxite, aluminum, aluminum oxides and aluminum hydroxides to AHS can also acidify any other metal impurities that may be present in recycled aluminum or bauxite, thereby allowing said metal impurities to react within the AHS and/or the final MP. In cases wherein heavy metal contamination is not an issue and/or the bauxite is pure enough from other earthen contaminants, both AHS and MP can be formed utilizing the raw bauxite. Any metal oxides that do not enter the MP complex can be used for soil stabilization.
[0000] Energy
[0166] The instant invention manages hazardous materials, heat energy, chemical energy, electrical energy, as well as investments in equipment and raw materials more effectively than previous processes, which focused primarily on formation of the polynucleate aluminum compounds and/or disinfectants. In contrast, the instant invention focuses on the processes of MP production and disinfectant production, incorporating methods to manage materials and energy not taught previously. Due to this management, the cost of manufacture of MP(s) and ACS, or AHS or MAS is much less than that previously. Due to this management, the cost of manufacture of a disinfectant and/or an oxidant is much less than that previously.
[0167] The metal acid reactor (MAR) used to form AHS and/or MAS is also preferably placed near or adjacent to the EU and/or the HAR and preferably adjacent to the MPR so that the enthalpy of reaction to from MAS or AHS can be utilized in the MPR. It is preferred that the MPR and the MAR, and most preferably the HAR be the same equipment, e.g. the same vessel, such that in that same vessel: a) an aqueous solution of said halide acid is formed from the reaction of said halide acid in water, b) said MAS is formed by the reaction of said metal(s) in said halide acid, and c) said MP is formed by the reaction of said at least one metal(s) in said MAS.
[0168] The MPR is preferably adjacent or near the EU and/or the BRP so that the enthalpy of alumina formation can be utilized in the formation of MP(s). It is preferred that a vent scrubber be placed on the reactor to control halide acid gas emissions. The MPR may be equipped to operate at elevated temperature, pressure or both to form MP(s). It is preferred that the MPR be operated at approximately 100-150° C. (212-302° F.); however, depending on the final product composition, the MPR can be operated between approximately 30-200° C. (86-381° F.). While higher temperatures allow for an increase in the reaction rate constant for MP formation, increases in MPR operating temperature require a corresponding increase in the operating pressure to maintain reactants in an aqueous solution (H 2 O, Al, OH, Cl, etc.) Reactor pressure can be 1 to 7 atmospheres absolute, wherein 1 to 4 atmospheres absolute is preferred.
[0169] Heat energy, enthalpy, or temperature of matter, may be obtained from: SAR or SACP; sulfoxy salt formation; calcium hydroxide formation; the electrolysis unit; formation of a calcium sulfoxy salt; pH adjustment; halogen dioxide formation; metal halate formation; metal halide acid formation, and halide acid formation. Energy will be required for bauxite purification to alumina, if bauxite is used and needs to be purified. Energy will be required for MP formation in the MPR. Energy will be required for recycled aluminum purification, if employed. Depending on production rates and the type of raw materials utilized, energy can be easily transferred from one reaction vessel to another (via heat transfer of water and/or steam, vessel water jacketing and vessel steam jacketing, or in the form of the product itself) so that there is maximal efficiency in the use of enthalpy from chemical reactions and usage as hot water and/or steam energy.
[0170] It is preferred that the energy from the formation of at least one selected from a list consisting of: SAR; bisulfate or bisulfite formation; calcium hydroxide formation; the electrolysis unit; formation of a calcium sulfoxy salt, pH adjustment, halogen dioxide formation, metal halate formation, metal AHS or MAS formation, halide acid formation, and any combination therein is used to heat water and/or steam. It is preferred that the heated water and/or steam is at least partially used to heat at least one selected from a list consisting of: the aqueous reaction of a metal halide solution with a metal to form a polynucleate metal compound, the reaction of a metal hydroxide with a halide acid to form a metal hypohalite, heating and/or reducing the water in a calcium sulfoxy salt, heating and/or reducing the water in a group IA or a group IIA sulfoxy salt, and any combination therein.
[0171] It is most preferred to manufacture at least one of an: MP, AHS, hypohalite, halite, halate and halogen oxide without vehicular transportation of hazardous materials, which would include at least one selected from a list comprising: metal acid solution, halide acid solution, sulfuric acid and caustic.
[0000] Construction Materials
[0172] It is preferred that said metal sulfoxy salt and/or said gypsum product be used in wall-board, sheetrock, manufacture. It is most preferred that said metal sulfoxy salt and/or gypsum product comprise or be blended with at least one selected from a list consisting of: sodium sulfate, lime, hydrated lime, calcium sulfate, magnesium sulfate, aluminum sulfate, silicone sulfate, sodium carbonate, calcium carbonate, magnesium carbonate, aluminum carbonate, silicone carbonate, silica, silicates, sand, wax, glass, glass fiber, paper, adhesive, cement and any combination thereof to form a wall-board product. It is preferred that said sulfoxy salt, gypsum product or wallboard product be used in the manufacture of construction materials. It is most preferred that said construction materials comprise a wall-board or sheet-rock type product.
[0173] It is an embodiment that said gypsum product is used in soil stabilization.
[0000] Manufacturing Process Flow Paths
[0174] A preferred embodiment of the instant invention is to form within a manufacturing plant, manufacturing process systems and/or flow paths.
[0175] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein water or steam obtain heat energy via heat transfer equipment from at least a portion of the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0176] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a halide acid and a metal sulfoxy salt from the reaction of a metal halide salt with a sulfoxy acid. It is most preferred that said metal comprise sodium. It is most preferred that said halide comprise chlorine.
[0177] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a calcium sulfoxy salt from the reaction of a calcium hydroxide with a metal sulfoxy salt. It is most preferred that said metal comprise sodium.
[0178] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a metal halide solution from the reaction of at least one metal with a halide acid. It is most preferred that said metal comprise sodium. It is most preferred that said halide comprise chlorine.
[0179] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a metal sulfoxy salt from the reaction of a metal hydroxide with a sulfoxy acid. It is most preferred that said metal comprise sodium.
[0180] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a halogen dioxide from the reaction of a metal halate with a sulfoxy acid and sulfur dioxide. It is most preferred that said metal comprise sodium. It is most preferred that said halide comprise chlorine.
[0181] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a halogen dioxide from the reaction of a metal halate with a sulfoxy acid and hydrogen peroxide. It is most preferred that said metal comprise sodium. It is most preferred that said halide comprise chlorine.
[0182] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a metal halite from the reaction of a halogen dioxide with a halogen acid. It is most preferred that said metal comprise sodium. It is most preferred that said halide comprise chlorine.
[0183] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy of formation of a metal halite from the reaction of a halogen dioxide with hydrogen peroxide and a metal hydroxide. It is most preferred that said metal comprise sodium. It is most preferred that said halide comprise chlorine.
[0184] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein steam and/or hot water energy is obtained by heat transfer from at least a portion of the energy from an EU.
[0185] It is a preferred embodiment to form at least one plant or manufacturing process flow path, wherein any of said steam and/or hot water energy is used via heat transfer to heat at least one selected from the list consisting of: an MPR unit, an MAR unit, a bleach unit, an HAR unit, a halogen dioxide generation unit, and air. It is most preferred that said metal comprise sodium. It is most preferred that said halide comprise chlorine.
[0186] It is a preferred embodiment that at least one MPR, at least one MAR, and at least one HAR, form a plant or manufacturing process flow path, wherein said at least one MAR is upstream of said at least one MPR, wherein said at least one HAR is upstream of said at least one MAR, wherein an MP is formed in said at least one MPR by reacting at least one metal with an MAS solution formed in said at least one MAR, and wherein said halide acid is formed in said at least one HAR by reacting a metal halide salt with a sulfoxy acid.
[0187] It is a preferred embodiment that at least one MPR, at least one MAR, at least one SAR, and at least one HAR, form a plant or manufacturing process flow path, wherein said at least one MAR is upstream of said at least one MPR, wherein said at least one HAR is upstream of said at least MAR, wherein said SAR is upstream of said HAR, wherein a polynucleate metal compound is formed in said at least one MPR by reacting at least one metal with MAS formed in said at least one MAR, wherein said MAR forms said MAS by reacting a metal with a halide acid, and wherein said halide acid is formed in said at least one HAR by reacting a metal halide salt with a sulfoxy acid formed in said at least one SAR.
[0188] It is a preferred embodiment that at least one MPR, at least one MAR, at least one SAR, at least one HAR, and at least one EU form a plant or manufacturing process flow path, wherein said at least one MAR is upstream of said at least one MPR, wherein said at least one HAR is upstream of said at least one MAR, wherein said SAR is upstream of said HAR, wherein said at least one EU is upstream of said at least one MAR, wherein a polynucleate metal compound is formed in said at least one MPR by reacting at least one metal with an MAS formed in said MAR, wherein said MAS is formed in said MAR by reacting a halide acid with a metal, wherein said halide acid is formed in at least one HAR and/or at least one EU, and wherein within said HAR said halide acid is formed by reacting a metal halide salt with a sulfoxy acid formed in said at least one SAR.
[0189] It is preferred to form a plant or manufacturing process flow path, wherein a unit or units comprising an MPR is downstream of at least one MAR unit manufacturing ACS and/or MAS. It is preferred that said MAR is downstream of at least one EU and/or HAR forming a halide acid.
[0190] It is preferred to form a plant or manufacturing process flow path, wherein at least one MPR is downstream of at least one MAR, wherein said MAR forms ACS and/or MAS and is downstream of at least one EU and/or HAR forming a halide acid, wherein the sulfoxy acid, preferably H 2 SO 4 , for said HAR is manufactured in a unit or units comprising an SACP and the electricity for said EU is created in a generator driven by a steam turbine, wherein steam energy turns said steam turbine, and wherein said steam energy is obtained from the formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0191] It is preferred for the MPR and MAR unit(s) to be one and the same, such that: a first reaction forms a halide acid from the reaction of a halide acid gas in water or addition of an aqueous halide acid to the reactor; a second reaction forms an MAS (preferably ACS) by the addition of at least one metal (preferably comprising alumina) to said halide acid; and, a third reaction forms an polynucleate metal compound from the addition of at least one metal (preferably comprising alumina) to said reactor.
[0192] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one unit forms a disinfectant and/or an oxidant in an EU, wherein the electricity for electrolysis in said EU is obtained from a generator driven by a steam turbine, wherein the steam energy used to turn said steam turbine is obtained from heating at least one of water and steam by heat transfer from at least a portion of the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0193] It is a preferred embodiment that an EU and an HAR form a plant or manufacturing process flow path, wherein at least one disinfectant is formed in said EU and at least one halide acid and a metal sulfoxy salt is formed in an HAR, wherein said halide acid(s) can be used to further form an additional disinfectant in at least one unit downstream of said EU by reacting said halide acid formed in said HAR with a disinfectant formed in said EU; it is most preferred that said disinfectant formed in said EU is a metal halate and that the disinfectant formed with the reaction of said metal halate with said halogen acid be the corresponding halogen dioxide, preferably chlorine dioxide. It is preferred that said metal comprise a group IA or group IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0194] It is a preferred embodiment that at least one SAR, at least one EU, at least one HAR, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU and said at least one HAR, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one HAR and/or said at least one EU, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR or one of said at least one EU, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from said at least one separator or one of said at least one EU or with a halogen acid from said at least one HAR or one of said at least one EU, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from said at least one HAR or one of said at least one EU with the metal hydroxide from said at least one separator or one of said at least one EU, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0195] It is a preferred embodiment that at least one EU, at least one HAR, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one HAR and/or said at least one EU, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 or with H 2 O 2 from said at least one EU and a sulfoxy acid or with a halogen acid from said at least one HAR or one of said at least one EU, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from said at least one separator or one of said at least one EU or with a halogen acid from said at least one HAR or one of said at least one EU, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from said at least one HAR or one of said at least one EU with the metal hydroxide from said at least one separator or one of said at least one EU, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0196] It is a preferred embodiment that at least one HAR, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one HAR, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid, wherein said halogen dioxide generator produces a halogen dioxide by reacting a metal halate with a sulfoxy acid and SO 2 or with H 2 O 2 and a sulfoxy acid or with a halogen acid from said at least one HAR, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 and a metal hydroxide from said at least one separator or with a halogen acid from said at least one HAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from said at least one HAR with the metal hydroxide from said at least one separator, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0197] It is a preferred embodiment that at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said halogen dioxide generator produces a halogen dioxide by reacting a metal halate with a sulfoxy acid and SO 2 or with H 2 O 2 and a sulfoxy acid or with a halogen acid, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 and a metal hydroxide from said at least one separator or with a halogen acid, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid with the metal hydroxide from said at least one separator, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0198] It is a preferred embodiment that at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting a halide acid with the metal hydroxide from said at least one separator, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0199] It is a preferred embodiment that at least one at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0200] It is a preferred embodiment that at least one SAR, at least one HAR, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one HAR, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one HAR, wherein the electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting a metal halate with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 and a metal hydroxide from said at least one separator or with a halogen acid from said at least one HAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from said at least one HAR with the metal hydroxide from said at least one separator, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by removing water from said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0201] It is a preferred embodiment that at least one SAR, at least one EU, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one EU, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from one of said at least one EU, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from said at least one separator or one of said at least one EU or with a halogen acid from at least one EU, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from one of said at least one EU with the metal hydroxide from said at least one separator or one of said at least one EU, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0202] It is a preferred embodiment that at least one SAR, at least one EU, at least one HAR, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU and said at least one HAR, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one HAR and/or said at least one EU, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from said at least one HAR or one of said at least one EU with the metal hydroxide from said at least one separator or one of said at least one EU, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0203] It is a preferred embodiment that at least one SAR, at least one HAR, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one HAR, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one HAR, wherein electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from said at least one HAR with the metal hydroxide from said at least one separator, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0204] It is a preferred embodiment that at least one SAR, at least one EU, at least one slaker, at least one gypsum unit, at least one separator, at least one bleach unit, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein said at least one separator is upstream of said at least one bleach unit, wherein said at least one bleach unit is downstream of said at least one EU, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from one of said at least one EU, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from said at least one separator or one of said at least one EU or with a halogen acid from one of said at least one EU, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a metal hypohalite is formed in said at least one bleach unit by reacting the halide acid from one of said at least one EU with the metal hydroxide from said at least one separator or one of said at least one EU, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0205] It is a preferred embodiment that at least one SAR, at least one HAR, at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one HAR, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0206] It is a preferred embodiment that at least one SAR, at least one EU, at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0207] It is a preferred embodiment that at least one SAR, at least one EU, at least one HAR, at least one halogen dioxide generator, and at least one metal halite unit, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU and said at least one HAR, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR or one of said at least one EU, and wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from one of said at least one EU or with a halogen acid from said at least one HAR or one of said at least one EU. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0208] It is a preferred embodiment that at least one SAR, at least one EU, at least one halogen dioxide generator, and at least one metal halite unit, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from one of said at least one EU, and wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from one of said at least one EU or with a halogen acid from one of said at least one EU. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0209] It is a preferred embodiment that at least one SAR, at least one HAR, at least one halogen dioxide generator, and at least one metal halite unit, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one HAR, wherein electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting a metal halate with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR, and wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 and a metal hydroxide or with a halogen acid from said at least one HAR. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0210] It is a preferred embodiment that at least one SAR, at least one EU, at least one HAR, and at least one halogen dioxide generator, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU and said at least one HAR, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR or one of said at least one EU. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0211] It is a preferred embodiment that at least one SAR, at least one EU, and at least one halogen dioxide generator, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from one of said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from one of said at least one EU. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0212] It is a preferred embodiment that at least one SAR, at least one HAR, and at least one halogen dioxide generator, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one HAR, wherein electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, and wherein said halogen dioxide generator produces a halogen dioxide by reacting a metal halate with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0213] It is a preferred embodiment that at least one SAR, at least one EU, at least one HAR, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU and said at least one HAR, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR or one of said at least one EU, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from said at least one separator or one of said at least one EU or with a halogen acid from said at least one HAR or one of said at least one EU, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0214] It is a preferred embodiment that at least one SAR, at least one EU, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU, wherein said at least one EU is upstream of said at least one halogen dioxide generator, wherein said at least one halogen dioxide generator is upstream of said at least one metal halite unit, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from one of said at least one EU, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from said at least one separator or one of said at least one EU or with a halogen acid from one of said at least one EU, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0215] It is a preferred embodiment that at least one SAR, at least one HAR, at least one halogen dioxide generator, at least one metal halite unit, at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one HAR, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 and a sulfoxy acid from said at least one SAR or with a halogen acid from said at least one HAR, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 and a metal hydroxide from said at least one separator or with a halogen acid from said at least one HAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0216] It is a preferred embodiment that at least one SAR, at least one HAR, at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one HAR, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein electricity is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein said at least one HAR forms a halogen acid and a metal sulfoxy salt by reacting a metal halide salt with a sulfoxy acid from said at least one SAR, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with the metal sulfoxy salt from said HAR, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by removing water from said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0217] It is a preferred embodiment that at least one SAR, at least one EU, at least one slaker, at least one gypsum unit, at least one separator, and at least one dryer, form a plant or manufacturing process flow path, wherein said SAR is upstream of said at least one EU, wherein said at least one slaker is upstream of said at least one gypsum unit, wherein said at least one gypsum unit is upstream of said at least one separator, wherein said at least one separator is upstream of said at least one dryer, wherein the electricity for electrolysis in said EU(s) is obtained from a generator driven by a steam turbine, wherein the steam used to turn said steam turbine to create said electricity is obtained from heat transfer from at least a portion of the energy obtained during formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein, wherein said at least one SAR forms a sulfoxy acid by reacting S with air or O 2 and then H 2 O, wherein one of said at least one EU forms H 2 O 2 from water utilizing H 2 SO 4 as a catalyst from said at least one SAR, wherein said halogen dioxide generator produces a halogen dioxide by reacting the metal halate from one of said at least one EU with a sulfoxy acid and SO 2 from said at least one SAR or with H 2 O 2 from said at least one EU and a sulfoxy acid from said at least one SAR or with a halogen acid from one of said at least one EU, wherein a metal halite is formed by the reaction of said halogen dioxide formed in said halogen dioxide generator with H 2 O 2 from one of said at least one EU and a metal hydroxide from said at least one separator or one of said at least one EU or with a halogen acid from one of said at least one EU, wherein said at least one slaker forms an aqueous solution of calcium hydroxide by reacting calcium, calcium oxide or calcium hydroxide with water, wherein said at least one gypsum unit forms an aqueous metal hydroxide and a solid metal sulfoxy salt by reacting the aqueous calcium hydroxide from said slaker with a metal sulfoxy salt, wherein said at least one separator produces an aqueous metal hydroxide and a moist calcium sulfoxy salt, wherein a product comprising calcium sulfoxy salt or a hydrated calcium sulfoxy salt is obtained from said at least one dryer by reducing the water in said calcium sulfoxy salt. It is preferred that said metal comprise a Group IA or IIA metal. It is most preferred that said metal comprise sodium. It is most preferred that said halogen comprise chlorine.
[0218] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one unit performs ASP, thereby producing O 2 and N 2 , wherein said ASP is powered by electricity and/or torque, wherein said electricity and/or torque is produced from steam, and wherein said steam is converted heat energy from at least a portion of the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0219] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one ASP separates O 2 from air, wherein said at least one ASP is powered by at least one of a steam engine powered by steam and an electric motor powered by electricity, wherein said O 3 is obtained from electrolysis of O 2 , wherein at least a portion of the electricity for said electrolysis is produced from a generator turned by a steam turbine, and wherein steam to power said steam engine and said steam turbine is at least partially obtained from at least a portion of the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0220] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one unit performs electrolysis, thereby producing O 2 and H 2 from H 2 O, wherein said electrolysis is powered by electricity, wherein at least a portion of said electricity is produced in a generator turned by a steam turbine, and wherein said steam turbine is at least partially turned by converted energy from at least a portion of the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0221] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one unit electrolyzes O 2 to O 3 , and wherein said O 2 is obtained from electrolysis of H 2 O, thereby producing O 2 and H 2 , wherein at least a portion of the electricity for said electrolysis is created in a generator driven by a steam turbine, wherein said steam turbine is at least partially turned by steam obtained from at least a portion of the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0222] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one unit electrolyzes H 2 O 2 from H 2 SO 4 via H 2 S 2 O 8 and H 2 O, wherein the electricity for said electrolysis is created in a generator driven by a steam turbine, wherein said steam turbine is turned by steam obtained from at least a portion of the energy of formation of at least one selected from a list comprising: SO 2 from S and air or O 2 , SO 3 from SO 2 and air or O 2 , H 2 SO 3 from SO 2 and H 2 O, H 2 SO 4 from SO 3 and H 2 O, oleum from H 2 SO 4 and SO 3 , H 2 SO 4 from oleum and H 2 O, and any combination therein.
[0223] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one unit recycles at least a portion of the H 2 byproduct from electrolysis as an energy source to make electricity, wherein said electricity is generated in at least one of a combustion engine and a fuel cell. It is a preferred embodiment to utilize at least a portion of said electricity in the EU to manufacture at least one disinfectant and/or oxidant. It is preferred to convert steam energy into electricity with a steam turbine, as is known in the art.
[0224] It is a preferred embodiment to form a plant or manufacturing process flow path, wherein at least one unit recycles at least a portion of the H 2 byproduct from electrolysis as an energy source to heat the reaction of said metal halide salt with said sulfoxy acid.
[0225] It is a preferred embodiment that sulfoxy acid from said SAR is transferred to said HAR, wherein said sulfoxy acid heat energy and/or temperature is as near that of the temperature in said SAR as is practical, so that said heat energy within said sulfoxy acid is available to said HAR.
[0000] Materials of Construction
[0226] It is an embodiment that all materials of construction in the instant invention be those as are known in the art of each chemistry processed. It is preferred that materials which contact said sulfoxy acid be at least one selected from a list consisting of: carbon steel, Hastelloy, Inconel®, Incoloy®, titanium, zirconium, ceramic, plastic and any combination therein. It is preferred that materials which contact said halide acid be at least one selected from a list consisting of: Hastelloy, Inconel®, Incoloy®, titanium, zirconium, ceramic, plastic, and any combination therein, wherein Hastelloy C, zirconium and PVC are most preferred. It is preferred that materials which contact hot water be at least one selected from a list consisting of: Hastelloy, Inconel, titanium, zirconium, ceramic, stainless steel and plastic.
[0000] Testing
[0227] Bench scale tests reacting ACS in solution with aluminum hydroxide at a temperature of 110-140° C. (230-284° F.) for 1.5 to 5 hours, whereby the reaction of Al x Cl y (OH) z is formed have been performed. The formation of ACS from aluminum metal was performed in one case and aluminum hydroxide was performed in the second case. In both cases, HCl was formed by the reaction of chlorine gas into water, where the water solution was heated continuously to 60° C. (140° F.) for 15 minutes to assure complete chloride formation. In the third test, a portion of the aluminum hydroxide was replaced with MgO forming Al x Mg w Cl y (OH) z . In a fourth test, a portion of the ACS was replaced with MgCl 2 again forming Al x Cl y (OH) z . In a fifth test, a portion of the aluminum hydroxide was replaced with lime, CaO, forming Al w Ca w Cl y (OH) z . In a sixth test, sulfuric acid was added to the ACS forming Al x Mg w Cl y (OH) z (SO 4 ) v . In a seventh and poor-performing test, a portion of the ACS was replaced with ferric chloride. In an eighth test, a portion of the aluminum was replaced with copper forming Al x Cu w Cl y (OH) z ; this rather green product revealed a shelf life of over 2.5 years before forming a precipitate. In test nine, the ACS was replaced with a waste catalyst stream form Dow Chemical containing ACS. Test ten was a field coagulation test of the final MP made in Example “8.” In an eleventh test, an MAS was prepared by dissolving CuCl 3 in water, which was then reacted with MgO. In all cases, the relationship OH:Al or OH:metal in the resulting compound became 0.5 to 1.5; where, this relationship is preferably greater than 1.2. In all cases the pH of the final solution was between 4.0 and 5.0. In all cases, improved results were obtained with high-shear mixing as compared to low. It was found that at high shear mixing energies, a greater proportion of the aluminum went into the MP and the tendency to form a gelatinous precipitate was reduced.
[0228] In test twelve, salts were reacted with concentrated sulfuric acid. While ammonium is not a metal, a test was performed with ammonium chloride since the ammonium cation has “metal-like” qualities in salt formation. Even though the ammonium cation is not the most practical “metal-like” cation, given the results, the term “metal” in metal halides is to include “metal-like” moieties, preferably the ammonium cation. The test results are reviewed below:
Example 1
[0229] Chlorine gas is slowly bubbled into a 1-L beaker until the Sg of the aqueous solution is approximately 1.08 to 1.1. The acidic solution is continuously stirred and heated to 60° C. for 15 minutes; after which, 50 grams of aluminum metal are dissolved into solution while slowly stirring for 15 minutes to prepare the ACS. 300 ml of this ACS having an aluminum content of approximately 5% is then heated to 120 C and stirred vigorously while slowly adding 30 gm of Al(OH) 3 powder. The system is kept at 120° C. and stirred vigorously for 3 hours, after which all of the powder is noted to have gone into solution. The liquid was allowed to cool. The final product was a cloudy liquid having an aluminum content of approximately 10%.
Example 2
[0230] Chlorine gas is slowly bubbled into a 1-L beaker until the Sg of the aqueous solution is approximately 1.08 to 1.1. The acidic solution is continuously stirred and heated to 60 C for 15 minutes; after which 100 grams of Al(OH) 3 powder is dissolved into solution while slowly stirring for 165 minutes to prepare the ACS. 300 ml of this ACS having an aluminum content of approximately 5 percent is then heated to 130° C. and stirred vigorously while slowly adding 30 gm of Al(OH) 3 powder. The system is kept at 130 C and stirred vigorously for 3 hours, after which all of the powder is noted to have gone into solution. The liquid was allowed to cool. The final product was a cloudy liquid having an aluminum content of approximately 10 percent.
Example 3
[0231] An ACS from Gulbrandsen Technologies, GC 2200, was utilized for the ACS. This sample of GC 2200 measured 10.1 percent Al 2 O 3 having a Sg of 1.28 and due to the yellow color contained iron. To an autoclave, provided with a stirrer, 300 ml of the ACS were added along with 5 gm of MgO from Premiere Services and 25 gm of laboratory grade Al(OH) 3 powder. The mixture was heated to 120 C and stirred vigorously for five hours. The liquid was allowed to cool. The final product was clear having an aluminum content of approximately 6 percent and a magnesium content of approximately 2 percent.
Example 4
[0232] An ACS from Gulbrandsen Technologies, GC 2200, was utilized for the ACS. This sample of GC 2200 measured 10.1 percent Al 2 O 3 having a Sg of 1.28 and due to the yellow color contained iron. To a 2-L beaker, 300 ml of the ACS were added along with 10 gm of MgCl 2 ×6H 2 O crystals and 25 gm of laboratory grade Al(OH) 3 powder. The mixture was heated to 110° C. and stirred vigorously for four hours. The liquid was allowed to cool. The final product was clear having an aluminum content of approximately 10 percent and a magnesium content of approximately 2 percent.
Example 5
[0233] An ACS from Gulbrandsen Technologies, GC 2200, was utilized for the ACS. This sample of GC 2200 measured 10.1 percent Al 2 O 3 having a Sg of 1.28 and due to the yellow color contained iron. To an autoclave, 300 ml of the ACS were added along with 10 gm of CaO and 20 gm of laboratory grade Al(OH) 3 powder. The mixture was heated to 100° C. and stirred vigorously for four hours. The liquid was allowed to cool. The final product was cloudy having an aluminum content of approximately 7 percent and a calcium content of approximately 3 percent.
Example 6
[0234] An ACS from Gulbrandsen Technologies, GC 2200, was utilized for the ACS. This sample of GC 2200 measured 10.1 percent Al 2 O 3 having a Sg of 1.28 and due to the yellow color contained iron. To an autoclave, 300 ml of the ACS were added along with 10 ml of concentrated sulfuric acid and 10 gm of laboratory grade Al(OH) 3 powder. The mixture was heated to 140° C. and 25 psig stirring vigorously for four hours. The liquid was allowed to cool. The final product was clear having an aluminum content of approximately 6 percent.
Example 7
[0235] An ACS from Gulbrandsen Technologies, GC 2200, was utilized for the ACS. This sample of GC 2200 measured 10.1 percent Al 2 O 3 having a Sg of 1.28 and due to the yellow color contained iron. To an autoclave, 300 ml of the ACS were added along with 30 gm of alum and 10 gm of laboratory grade Al(OH) 3 powder. The mixture was heated to 140° C. and 25 psig and turned gelatinous.
Example 8
[0236] An ACS from Gulbrandsen Technologies, GC 2200, was utilized for the ACS. This sample of GC 2200 measured 10.1 percent Al 2 O 3 having a Sg of 1.28 and due to the yellow color contained iron. To a 2-L beaker, 300 ml of the ACS were added along with 10 gm of CuCl 2 ×6 H 2 O crystals and 25 gm of laboratory grade Al(OH) 3 powder. The mixture was heated to 100° C. and stirred vigorously for four hours. The liquid was allowed to cool. The final product was clear with a greenish tint having an aluminum content of approximately 8 percent and a copper content of approximately 2 percent.
Example 9
[0237] A waste catalyst from Dow Chemical (Freeport, Tex.) containing ACS was utilized for the ACS. The sample measured 18 percent Al 2 O 3 having a Sg of 1.3; due to the greenish color the sample had a small amount of organic contamination. To a 2-L beaker, 300 ml of the ACS were added along with 35 gm of laboratory grade Al(OH) 3 powder. The mixture was heated to 105° C. and stirred vigorously for four hours. The liquid was allowed to cool. The final product was clear with a greenish tint having an aluminum content of approximately 10 percent.
Example 10
[0238] At the time of this test, the city of Marshall, Tex. was in drinking water production using CV 1703 as the coagulant. (CV is a registered trademark of ClearValue.) CV 1703 is a blend that is by volume: 38% CV 1120, 42% CV 1130, 8% CV 3210 and 12% CV 3650. CV 1120 is an ACH measuring 23% Al 2 O 3 at 84% basicity, CV 1130 is an ACS that measures 10% Al 2 O 3 , CV 3210 is a 50% active Epi-DMA solution that measures 100+/−20 cps, and CV 3650 is a 20% active diallyl dimethyl ammonium chloride polymer that measures 2000+/−200 cps. Prior to using CV 1703, Marshall utilized CV 3650 in concert with alum. Alum was, at that previous time, used at 30 to 35 ppm along with CV 3650 at 1.5 ppm.
[0239] Marshall's raw water quality makes water purification difficult:
The raw alkalinity is less than 20 ppm and often as low as 6 ppm, The raw turbidity is normally 2 to 7 NTU and infrequently 10 to 15 NTU, The raw color varies from 20 to 400 Apparent Color Units (ACU), and The raw TOC ranges form 5 to 20 ppm; and UV absorbance 0.2 to 0.7 m −1 .
[0244] Prior to the use of CV 3650 with alum, Marshall operated with just alum and often went out of US EPA and Texas State permit having a final water turbidity of greater than 0.5 NTU; on Alum operation, Marshall frequently measured in excess of 0.20 mg/L of aluminum in the final drinking water. While CV 3650 significantly improved alum operations, water color values of over 200 ACU often required the use of CV 1703.
[0245] Prior to using CV 1703, Marshall produced filtered water at a turbidity of near 0.15 to 0.30 NTU under normal operating conditions and higher when the raw water color was a challenge. During operation with CV 1703, Marshall has had the ability to keep the filtered water turbidity under 0.08 NTU under all operating conditions with the settled water turbidity varying from 0.4 to 0.7 NTU. Per US EPA guidelines, Marshall must remove, at times, 45% of the raw water TOC and, at times, 50% of the raw water TOC. During the year 2000, when the raw water had a lower organic content and nearly all of the raw TOC measured DOC per the standard industry test, Marshall was frequently unable to obtain 45% TOC removal. Operation during this time did not produce any final filtered water that had an aluminum concentration of over 0.20 mg/L.
[0246] On Dec. 15, 1999, the MP made in Example 8 was jar-tested in comparison to CV 1120 and CV 1703. On that day the raw color measured 55, NTU measured 4.1 and UV measured 0.185 m −1 . At 15 ppm, CV 1703 obtained a settled turbidity of 0.96 NTU, 14 ACU and 0.071 m −1 . At 15 ppm, the MP from Example 8 obtained a settled turbidity of 0.69 NTU, 11 ACU and 0.074 m −1 .
Example 11
[0247] To a 2-L beaker, 250 ml of water was added prior to 50 gm of CuCl 2 ×6H 2 O crystals; the solution was pH adjusted to 1.0 with HCl. The resulting solution was then mixed with 30 gm of MgO powder. The mixture was heated to 100° C. and stirred vigorously for four hours. The liquid was allowed to cool. The final product was clear with a greenish tint having a copper content of approximately 5 percent and a magnesium content of approximately 5 percent.
Example 12
[0248] Five salt compositions are reacted with concentrated sulfuric acid to test the efficacy of halide acid formation and sulfate/bisulfite formation.
[0249] In the first test, 4 gm of normal table salt (sodium chloride) is placed in a beaker containing 2 g of concentrated sulfuric acid. In this test a rather violent reaction takes place, wherein HCl gas is obviously released due to the tell tale chlorine odor; in the bottom of the beaker a solid precipitate forms which is obviously sodium bisulfate.
[0250] In the second test, 4 gm of ammonium chloride is placed into a beaker containing 2 gm of concentrated sulfuric acid. In this test a rather violent reaction takes place, wherein HCl gas is obviously released due to the tell tale chlorine odor; in the bottom of the beaker a solid precipitate forms which is obviously the ammonium sulfate salt.
[0251] In the third test, 4 gm of CuCl 3 ×6H 2 O crystals are placed into a beaker containing 2 gm of concentrated sulfuric acid. In this test an aggressive reaction takes place, wherein HCl gas is obviously released due to the tell tale chlorine odor; in the bottom of the beaker a solid precipitate forms which is obviously copper sulfate.
[0252] In the fourth test, 4 gm of AlCl 3 ×6H 2 O crystals are placed into a beaker containing 2 gm of concentrated sulfuric acid. In this test an aggressive reaction takes place, wherein HCl gas is obviously released due to the tell tale chlorine odor; in the bottom of the beaker a solid precipitate forms which is obviously aluminum sulfate.
[0253] In the fifth test, 4 gm of MgCl 3 ×6H 2 O crystals are placed into a beaker containing 2 gm of concentrated sulfuric acid. In this test an aggressive reaction takes place, wherein HCl gas is obviously released due to the tell tale chlorine odor; in the bottom of the beaker a solid precipitate forms which is obviously magnesium sulfate.
[0254] Certain objects are set forth above and made apparent from the foregoing description. However, since certain changes may be made in the above description without departing from the scope of the invention, it is intended that all matters contained in the foregoing description shall be interpreted as illustrative only of the principles of the invention and not in a limiting sense. With respect to the above description, it is to be realized that any descriptions, drawings and examples deemed readily apparent and obvious to one of skill in the art and all equivalent relationships to those described in the specification are intended to be encompassed by the instant invention.
[0255] 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. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall in between.
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As population density increases, the transportation of hazardous chemicals, including acids and disinfectants, lead to an increased incidence of spills while the consequences of spills become more serious. While solutions of halide acids, hypohalites and halites are safer disinfectants for transportation, handling, storage and use than traditional gaseous chlorine, the manufacturing cost of these disinfectants has here-to-fore limited their use. Economical processes are presented for the manufacture of O 2 , halogen oxides, halide acids, hypohalites, and halates; as well as polynucleate metal compounds, metal hydroxides and calcium sulfate hydrate (gypsum). The instant invention presents methods and processes that incorporate the use of sulfur. This is while environmental regulators, such as the US EPA, require an increased removal of sulfur from hydrocarbon fuels, thereby creating an abundance of sulfur, such that the refining industry is in need of a way to dispose of said abundance of sulfur.
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TECHNICAL FIELD
This invention relates to devices for mixing fuel gas and more particularly, to a regulator for mixing a pressurized fuel gas with air, for supplying the mixture to an internal combustion engine.
BACKGROUND ART
Vehicles are powered by internal combustion engines which operate on gasoline mixed with air in a carburetor. Vacuum from the engine draws gasoline through a venturi structure for atomization. The gasoline and air mixture is then drawn into the engine for ignition.
Demands for fuel efficiency and anticipated scarcity of liquid fuels derived from petroleum has led to a search for other fuels which can be used instead of gasoline. Some potential alternatives include gaseous, volatile fuels such as propane, butane, methane, compressed or liquified natural gas.
The use of vehicles operating on alternate fuels, natural gas or LP gas as the primary fuel, with gasoline being the alternate fuel, should be limited to operations where the equipment is lightly loaded such as taxicabs, delivery vans, pickups, etc. The inherent loss of volumetric efficiency of the engine, due to the vapor density difference between the gaseous fuels and gasoline as well as the heat input required in the intake manifold for gasifying the gasoline, reduces the performance reserve at the maximum engine demand.
Many simple, small gasoline carburetors can be altered to receive gaseous fuels without upsetting the gasoline operation. More complex systems such as two-barrel and four-barrel carburetors, usually require the use of adapters. The use of solenoids on both the gasoline line and the gaseous fuel line with a selector switch in the driver compartment provides a simple convenient means for the operator to change from one fuel to the other.
To allow the operation of the alternate fuel system (gasoline) with a minimum adverse effect on the system, the adapters require large air capacities. The venturi signals from such adapters are quite low and require either a very sensitive fuel device for starting and idling or complex support systems to provide these functions.
DISCLOSURE OF THE INVENTION
In accordance with the present invention, a regulator is provided for mixing pressurized fuel gas with air, which mixture is then applied to an internal combustion engine. The flow of gas is controlled in response to a vacuum. A conduit applies the vacuum with a source of gas, with a main valve disposed in the conduit for regulating the gas flow. A diaphragm in fluid communication with the conduit actuates the main valve in response to changes in the vacuum.
BRIEF DESCRIPTION OF DRAWINGS
A more complete understanding of the invention and its advantages will be apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a sectional view of one embodiment of the present invention suitable for small carburetors;
FIG. 2 is a sectional view of an adapter distributor system for two fuels; and
FIG. 3 is a sectional view of another adapter distributor system for two fuels.
DETAILED DESCRIPTION
FIG. 1 illustrates a regulator 10 which is to serve to mix air with fuel gas. The regulator 10 comprises a housing 12 which contains control elements to be described. Fuel gas to be regulated by regulator 10 is supplied as indicated by arrow A under pressure from a suitable source (not shown), but which is to be connected to the inlet 16. A passage 14 extends from inlet 16 and is connected by way of conduit 18 which leads to a fuel orifice 24 in a venturi throat structure 20. Air is supplied to the venturi structure from its upper end as indicated by arrow B.
A conventional carburetor 28 is also connected to throat 20 by way of tubes 28a and 28b. The venturi structure 20 is then secured as by bolts 26 to the fuel inlet structure of an internal combustion engine 8.
Housing 12 of regulator 10 includes a main fuel valve 30 which operates to open and close the passage at valve seat 32. Valve 30 is normally biased closed by spring 34. Fuel gas entering port 16 is controlled by the action of the valve 30. A pilot fuel valve 38 is positioned adjacent to the inlet 16 and upstream of the main valve 30. The pilot fuel valve 38 is normally biased closed on a seat 36 by action of a spring 40. Valve 38 acts to open and close a passage 44 leading from seat 36. Passage 44 is connected by way of a flow restricting pilot orifice 58 leading to a flow channel and by way of a flow restricting pilot orifice 56 to an upper chamber 60a. Fuel valve 30 is provided with a valve stem 30a which is connected to a main fuel valve diaphragm 86. A chamber 82a is formed in housing 12 above diaphragm 86. Chamber 82a is flow connected by way of restriction 84 to passage 62. A lower chamber 82b is formed in housing 12 below diaphragm 86 and is flow connected by passage 88 to channel 14.
Channel 62 leading from flow restriction 58 extends to a valve seat 76 which cooperates with an amplifier diaphragm 77. Diaphragm 77 separates under chamber 60a from lower chamber 60b. Lower chamber 60b is connected by way of passage 78 to a chamber 68b below a diaphragm 70. An upper chamber 68a is formed in housing 12 above diaphragm 70. Chamber 68b below diaphragm 70 is connected by way of a passage in which trim adjusting screw 90 is provided and leads to the passage 80 which connects to passage 14.
The chamber 68a above a control diaphragm 70 is connected by way of conduit 72 to the input of venturi 20. Control diaphragm 70 cooperates with a valve seat 66 to open and close the passage leading from the upper chamber 60a associated with amplifier diaphragm 77. Valve stem 39 connected to the second valve 38 is coupled to a disc-diaphragm unit 48. Thus, a chamber 46a is formed in housing 12 above diaphragm 48 and a chamber 46b is formed in housing 12 below diaphragm 48. Chamber 46a is connected to atmosphere by way of opening 50. Chamber 46b is connected to the lower end of venturi 20 by way of passage 52.
A butterfly valve 54 is located in throat 20 above the entrance of passage 52 and below the entrance of orifice 24.
In operation, the control device 10, having fuel inlet 16 and fuel valve 30, closed by spring 34, prevents the flow of fuel to outlet 14. A vacuum responsive diaphragm 48 opens pilot fuel valve 38, which normally is closed by spring 40. As the engine 8 demands fuel, engine vacuum acting through conduit 52, displaces the air beneath the diaphragm 48, unseating valve 38. This allows pressurized fuel to flow through the pilot orifices 56 and 58, from passage 44. The pilot charge across orifice 58 is throttled at seat 76 by amplifier diaphragm 77. The pilot charge across orifice 56 is throttled at seat 66 by the control diaphragm 70. The control diaphragm 70 is a very sensitive light diaphragm with its upper portion exposed to the free air flowing to the engine by way of conduit 72 and its bottom side exposed to the fuel flowing to the engine through passage 80 past the trim adjustment 90. The weight of the control diaphragm 70 acting on seat 66 places ample back pressure on the pilot charge across orifice 56 to open the main fuel valve 30, with the main fuel valve diaphragm 86 using the pilot charge across orifice 58. Under all operating conditions, the pressure difference across the control diaphragm 70 is the pressure difference required to float diaphragm 70. The pilot charge will never equal or exceed the engine's fuel demand at idle; there will always be fuel flowing by the main fuel valve 30 at idle. The trim adjustment is provided with screw 90 to restrict the pilot charge. The quantity of the pilot charge is constant and it all must pass adjusting screw 90; therefore, the fuel delivery pressure at outlet 14 is the air pressure acting on top of control diaphragm 70, plus the pressure difference required to float diaphragm 70, minus the pressure difference across screw 90 created by the pilot fuel velocity across screw 90.
If a pressure difference of 0.020 inches water is required to float control diaphragm 70 and if the idle screw 90 is so set to provide a pressure drop of 0.008 inches of water, there would be a positive pressure of 0.012 inches water at the outlet 14.
The additional fuel required to provide the back pressure of 0.012 inches across fuel orifice 24, is supplied from the main fuel valve 30. At idle, the signal of venturi 20 is equal to a minus pressure of 0.040 inches water when compared to the total air pressure as read at tube 72. In such case, the fuel pressure difference across fuel orifice 24 would be the venturi signal plus the fuel delivery pressure, or 0.052 inches of water. The pressure difference across venturi 20, which is the controlling orifice for the air, would be 0.040 inches of water. This would result in a richer air fuel ratio than the normal ratio as controlled by the values of venturi 20 and the fuel orifice 24. The fuel increase at idle would be approximately 15%, but quickly fades as the air demand increases. The venturi signal increases to the second power of air demand. If the air demand is doubled, the venturi signal would be 0.160 inches. The fuel signal would be 0.160 inches plus 0.012 inches or 0.172 inches. This is approximately 4% rich. The operational effect of the fuel pressure variations at inlet 16 is minimal. The valves of orifices 56 and 58 will be changed as the pressure at inlet 16 changes, but control diaphragm 70 must always float, provided there is ample pressure to open valve 30. As a fuel pressure loss occurs, less fuel flows across orifices 56 and 58 resulting in a pressure decrease across screw 90, but equally increasing the pressure at outlet 14 to float the control diaphragm 70, just as an increase fuel pressure increases the quantity across orifices 56 and 58. This increases the pressure difference across screw 90, lowering the pressure at outlet 14.
The fuel limiting factor of this device is not the physical size of the unit or even the main fuel valve size, but the size of the outlet 24 as it relates to the size of venturi 20, and the ratio and density factor of the fuel compared to the air. However, there is an advantage of oversized fuel valve in this type of device. The larger the fuel valve, the lower the inlet pressure can be, provided control can be established and maintained over the entire design pressure range.
This unit of FIG. 1 provides the ability to handle broad inlet pressure variations. The lack of diaphragm displacement and inertia, provides very good engine speed and load response, even though the system is very well dampened with orifices.
The control force ratio between the control diaphragm 70 and the main fuel valve 30, is a function of the area of the control diaphragm 70, divided by the area of orifice 64, multiplied by the area of the amplifier diaphragm 77, divided by the area of orifice 76a through seat 76, multiplied by the area of the main fuel valve diaphragm 86, divided by the area of the main fuel valve 30. A force ratio of diaphragm 70 to valve 30 of one hundred thousand to one is very easily achieved so it is easy for diaphragm 70 to manipulate valve 30 and with virtually no movement of the diaphragms. Diaphragm 70 simply responds to the condition of the fuel at outlet 14 as compared to the condition of the air at tube 72, and so positions itself over orifice 64 to maintain the proper opening of valve 30. The flow of pilot fuel from orifices 56 and 58 can join either upstream of adjustment 90 as shown or the pilot charge from the amplifier orifice 58 may join the fuel from orifice 56 downstream of screw 90.
FIGS. 2 and 3 illustrate hat-type adaptors mounted on top of gasoline carburetors. The use of this type of adaptor provides for a simple quick adaptation of the control unit shown in FIG. 1 to more complex carburetor units such as four-barrel carburetors.
Referring to FIG. 2, a hat-type adaptor 111 includes a support disc 112 having a central cylindrical port extension 113 which mates with and is mounted on the upper end of the throat structure 20 of FIG. 1. Throat structure 20 is associated with carburetor 28 to provide flow of liquid fuel to the throat structure 20 on demand for mixture with gaseous fuel coupled into the system by way of the adaptor 111.
Adaptor 111 has an annular chamber 114 which is formed on disc 112. An air filter of cylindrical form is supported on plate 112 and is clamped in place by an upper plate 116. A bolt 117 serves to anchor plate 116 to a fixed internal baffle 118 in adaptor 111.
The control unit of FIG. 1 is connected into the adapter 111 by way of channel 18, FIG. 1 which leads to the metering orifice 24, FIG. 2. Gaseous fuel drawn into the adaptor by way of tube 18 and orifice 24 enters into the airstream by way of discharge ports 119. Chamber 68a of FIG. 1 is connected to the adaptor 111 by way of tube 72. The vacuum connection 52 of FIG. 1 may be made to any suitable engine intake manifold in order to communicate with chamber 46b of FIG. 1.
Air from outside is drawn into the system by way of filter 115 and passes downward through venturi passage 120, which is in the form of an annular passage between the chamber 114 and baffle 118. It is to be understood means (not shown) support baffle 118 from the disc 112 so that the venturi passage 120 is fixed and serves to draw fuel through the metering orifice 24 into the carburetor system.
It is understood that the adaptor of FIG. 2 would be used in connection with carburetors where there is ample hood room. FIG. 3 illustrates a further embodiment of an adaptor where less hood room is available than in the case where the system of FIG. 2 is to be used.
Referring to FIG. 3, an adaptor 130 comprises a U-shaped pipe 131, one end of which telescopes over the upper end of the venturi structure 20 of FIG. 1. Carburetor 28 of FIG. 1 is coupled to supply liquid fuel through the venturi structure 20 to the engine 8. The opposite end 133 of the U-shaped tube 131 supports an upper plate 134, which is circular in form and which includes an annular chamber 135. An air filter 136 in the form of a short cylinder is secured to plate 134 by a bottom cover 137 which is secured to baffle 138 by way of a bolt 139.
The control unit of FIG. 1 is connected into the system of FIG. 3 by way of the tube 18 which leads to the metering orifice 24, thereby supplying gaseous fuel to the annular chamber 135. The gaseous fuel is delivered from chamber 135 by way of discharge ports 140. Air is drawn into the system through filter 136 and passes through the venturi passage 141. Chamber 68a of the control unit of FIG. 1 is connected into the adaptor unit by way of tube 72. The vacuum connection to chamber 46b may be made to any suitable engine intake manifold connection. As shown, the vacuum connection 52 connects into the venturi structure 20.
Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.
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A device (10) is provided for controlling the mixture of a gas with air in response to a vacuum drawing the air into a venturi (20). Housing (12) has a bore (14) therein for conveying the gas to the venturi (20). A main valve (30) is disposed in the bore (14) for controlling the flow of gas from a pressurized source. Structure forms a third chamber (68) having a control diaphragm (70) which divides the third chamber (86). One side of the diaphragm (70) is connected to the source of the gas, and the other side is connected upstream of the venturi (20). Structure forms a second chamber (60) with an amplifier diaphragm (74) dividing the second chamber (60) which amplifies the variations in pressure. Structure includes a main diaphragm (86) in fluid communication with the second chamber (60) for actuating the main valve (30) in response to amplified variations in the gas pressure.
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BACKGROUND
[0001] Store-and-forward devices, such as switches and routers, are used in packet networks, such as the Internet, for directing traffic at interconnection points. The store-and-forward devices include a plurality of line cards for receiving and transmitting data from/to external sources. The line cards are connected to one another via a backplane and a switching fabric. The backplane provides data paths between each line card and the switching fabric and the switching fabric provides configurable data paths between line cards. The backplane consists of a plurality of links (channels). Each channel is capable of transmitting data at a certain speed. If the line cards are transmitting data at speeds faster than the capabilities of the channels, the line cards can break the data up into sections and transmit the sections in parallel over several channels (strip the data). The number of channels required to support the line cards is based on the speed of the line cards and the capacity of the channels.
[0002] When a store-and-forward device has line cards operating at different speeds, the number of channels associated with each line card is based on the number of channels required for the line card operating at the highest speed. Accordingly, there will be channels associated with lower-speed line cards that are not used. Additionally, the switching fabric will have ports that are not used. This is an inefficient use of resources. The inefficiency grows as the difference in speed between line cards grows. As the capacity of switches and routers increases, the need for supporting ports with different speeds is becoming more common. Users need to be able to plug in legacy line cards into new systems, while populating a few slots with new line cards supporting ports with higher data rates. For example, an Internet router may have line cards with OC-48 and OC-192 ports today, and may need to support line cards with OC-768 ports in the future. In addition, higher-density line cards where the traffic from many external ports is aggregated into a single fabric port may require higher data-rate fabric ports.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The features and advantages of the various embodiments will become apparent from the following detailed description in which:
[0004] FIG. 1 illustrates an exemplary block diagram of a store-and-forward device, according to one embodiment;
[0005] FIG. 2 illustrates an exemplary block diagram of a crossbar-based packet switching fabric, according to one embodiment;
[0006] FIG. 3 illustrates an exemplary block diagram of a crossbar-based switching fabric having multiple switch planes, according to one embodiment;
[0007] FIG. 4 illustrates exemplary block diagram of a single crossbar-based switching fabric supporting multiple switch planes, according to one embodiment;
[0008] FIG. 5 illustrates an exemplary block diagram of a crossbar-based switching fabric operating at different speeds, according to one embodiment;
[0009] FIG. 6 illustrates an exemplary block diagram of a crossbar-based switching fabric with channels assigned by speed, according to one embodiment;
[0010] FIG. 7 illustrates an exemplary block diagram of the fabric scheduler, according to one embodiment;
[0011] FIG. 8 illustrates an exemplary block diagram showing elements of the crossbar configuration block in a fabric scheduler, according to one embodiment;
[0012] FIG. 9 illustrates exemplary valid destination memory and source address memory contents, according to one embodiment;
[0013] FIG. 10 illustrates exemplary contents of various crossbar configuration block memories, according to one embodiment; and
[0014] FIG. 11 illustrates an exemplary flowchart of operations of a crossbar configuration block, according to one embodiment.
DETAILED DESCRIPTION
[0015] A store-and-forward device, such as a packet switch or router includes a plurality of interface modules, a switch fabric for selectively connecting different interface modules, and a backplane for connecting the interface modules and the switching fabric. The interface modules can receive data from (receivers or ingress ports) and transmit data to (transmitters or egress ports) multiple sources (e.g., computers, other store and forward devices) over multiple communication links (e.g., twisted wire pair, fiber optic, wireless). Each of the sources may be capable of transmitting/receiving data at different speeds, different quality of service, etc. over the different communication links. The interface modules can transmit/receive data using any number of protocols including Asynchronous Transfer Mode (ATM), Internet Protocol (IP), and (Time Division Multiplexing) TDM. The data may be variable length or fixed length blocks, such as cells, packets or frames. The data received from external sources is stored in a plurality of queues. The queues may be stored in any type of storage device and preferably are a hardware storage device such as semiconductor memory, on-chip memory, off-chip memory, field-programmable gate arrays (FPGAs), random access memory (RAM), or a set of registers. The interface modules may be line cards or chips contained on line cards. The interface modules may be Ethernet (e.g., Gigabit, 10 Base T), ATM, Fibre channel, Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH) or various other types. A single line card may include a single interface module (receiver or transmitter) or multiple interface modules (receivers, transmitters, or a combination). A line card having multiple interface modules may have all the same type of interface modules (e.g., ATM) or may contain some combination of different interface module types. The backplane may be electrical or optical.
[0016] FIG. 1 illustrates an exemplary block diagram of a store-and-forward device 100 . The device 100 includes a plurality of line cards 110 that connect to, and receive data from, external links 120 via port interfaces 130 (a framer, a Medium Access Control device, etc.). A packet processor and traffic manager device 140 receives data from the port interface 130 and provides forwarding, classification, and queuing based on flow (e.g., class of service) associated with the data. A fabric interface 150 connects the line cards 110 to a switch fabric 160 that provides re-configurable data paths between the line cards 110 . Each line card 110 is connected to the switch fabric via associated fabric ports 170 (from/to the switch fabric 160 ). The switch fabric 160 can range from a simple bus-based fabric to a fabric based on crossbar (or crosspoint) switching devices. The choice of fabric depends on the design parameters and requirements of the store-and-forward device (e.g., port rate, maximum number of ports, performance requirements, reliability/availability requirements, packaging constraints). Crossbar-based fabrics are the preferred choice for high-performance routers and switches because of their ability to provide high switching throughputs.
[0017] FIG. 2 illustrates an exemplary block diagram of a crossbar-based packet switch fabric 200 . The fabric 200 connects to each line card via associated fabric ports 205 (e.g., to and from port for each line card). The fabric 200 includes a crossbar switching matrix 210 , a fabric scheduler 220 , input buffers 230 to hold arriving packets from the fabric ports 205 , input channels 240 to transmit data from the input buffers 230 to the crossbar matrix 210 (e.g., associated ports) output buffers 250 to hold packets prior to departing from the fabric ports 205 , and output channels 260 to transmit data from the crossbar matrix 210 (e.g., associated ports) to the output buffers 250 .
[0018] A backplane (not illustrated) consists of a plurality of channels (input 240 and output 260 ) that provide connectivity between the fabric ports 205 and the crossbar matrix 210 so as to provide switching connectivity between line cards. With advances in serial communication technologies, the channels (input 240 and output 260 ) are preferably high-speed serial links. High-speed serial data can be carried over either electrical backplanes or optical backplanes. If an optical backplane is used, the transmitting line card must convert electrical signals to optical signals and send the optical signals over fiber, and the destination line card must receive the optical signals from the fiber and reconvert them to electrical signals.
[0019] The crossbar matrix 210 is logically organized as an array of N×N switching points, thus enabling any of the packets arriving at any of N input ports to be switched to any of N output ports, where N represents the number of channels. These switching points are configured by the fabric scheduler 220 at packet boundaries. Typically, the packets are switched through the crossbar switching matrix 210 in batches, where a batch consists of at most one packet selected from each input port, in such a way that no more than one of the packets is destined for each out port.
[0020] Each of the packets, arriving at one of the input buffers 230 , has a header containing the destination port number where it needs to be switched. The fabric scheduler 220 periodically reads the destination port information from the headers of the packets stored in the input buffers 230 and schedules a new batch of packets to be transferred through the crossbar switching matrix 210 . All the packets in a batch (a maximum of N packets) are transferred in parallel across the crossbar switching matrix 210 . While the packets from a scheduled batch are being transferred through the crossbar 210 , the scheduler 220 can select the packets to form the next batch, so that the transmission of the new batch of packets can start as soon as transmission of the current batch ends. At the end of each batch of packets, the fabric scheduler 220 re-configures the crossbar switching matrix 210 so as to connect each input port to the output port where its next packet is destined to.
[0021] When the data rate for an individual fabric port is greater that the data rates supported by the data channels connecting the fabric port to the crossbar switching matrix 210 , the data from each fabric port is striped over multiple crossbar data channels. In such a system, each stripe from the fabric ports is switched through a separate crossbar plane.
[0022] FIG. 3 illustrates an exemplary crossbar switching fabric 300 having eight fabric ports 310 , each port operating at a data rate of 10 Gigabits/second (Gb/s), and four 8×8 crossbar planes 320 , having a maximum data rate of 2.5 Gb/s per channel. The data from each fabric port 310 is striped across the four crossbar switching planes 320 (e.g., Stripe 1 from each of the eight fabric ports 310 is switched through crossbar plane 1 , Stripe 2 through crossbar plane 2 , and so on). Such striping of the data can be performed at different granularities (e.g., bit, byte, word). The switching planes 320 may be separate crossbar devices, or may be configured within a larger crossbar device. That is, the 4 crossbar planes 320 may be constructed with (1) four 8×8 data channel physical crossbar devices (as illustrated in FIG. 3 ), (2) two 16×16 physical crossbar devices, with each physical crossbar devices serving two switching planes, or (3) a single 32×32 crossbar device serving all four switching planes.
[0023] FIG. 4 illustrates an exemplary crossbar switching fabric 400 including a 32×32 crossbar switching device 410 . Each fabric port connects to four ports on the crossbar switching matrix 410 . A first logical 8×8 switching plane would include the crossbar data input/output channels 0 , 4 , 8 , 12 , 16 , 20 , 24 , 28 . Likewise, a second logical 8×8 switching would include the crossbar data input/output channels 1 , 5 , 9 , 13 , 17 , 21 , 25 , 29 ; and so on.
[0024] When all of the fabric ports in the system do not operate at the same speed, the crossbar switching planes in the fabric is designed to accommodate the transfer rate from the highest-speed port. FIG. 5 illustrates an exemplary switch fabric 500 having eight fabric ports 510 where the first four ports (Ports 0 through 3 ) operate at a speed of 1 Gb/s each, the next two (Ports 4 and 5 ) operate at a speed of 2 Gb/s each, the last two ports (Ports 6 and 7 ) operate at 10 Gb/s each, and the maximum data rate of a crossbar data channel is 1 Gb/s. The crossbar switch fabric 500 includes ten 8×8 crossbar switching planes 520 to account for the fact that 10 crossbar channels are required to transmit the 10 Gb/s of fabric ports 6 and 7 . Ports 0 - 3 use only a first switching plane (only require a single channel and thus single switching plane), ports 4 - 5 use only the first and a second switching plane (only require two channels), and ports 6 - 7 use all ten switching planes. The striping is such that the number of crossbar planes used when sending data from a fabric port A to a fabric port B is based on the minimum of the data rates of the two ports. For example, transferring data between (a) port 0 (1 Gb/s) and port 5 (2 Gb/s) utilizes only a single (first) plane, (b) Port 4 (2 Gb/s) and Port 6 (10 Gb/s) utilizes only the first and second planes, and (c) port 6 (10 Gb/s) and port 7 (10 Gb/s) utilizes all ten planes.
[0025] The switch fabric 500 has a total of 80 data channels available and only 28, 4×1 (ports 0 - 3 )+2×2 (ports 4 - 5 )+2×10 (ports 6 - 7 ), are used in the system to connect to the fabric ports 510 . The remaining 52 (65%) are unused. This inefficiency can become even more severe with an increase in the number of ports and an increase in the difference between their data rates. For example, in a system with 128 ports (126 1 Gb/s ports and two 10 Gb/s ports) having a crossbar data channel rate of 1 Gb/s, a total of ten 128×128 crossbar switching planes are needed to construct the crossbar matrix. Only 146 (126×1+2×10) of the 1280 (or 11.4%) of the crossbar data channels will be used, and 88.6% of the channels are wasted.
[0026] FIG. 6 illustrates an exemplary switch fabric 600 , where each fabric port is assigned channels based on the speed of the fabric port instead of each fabric port being assigned the same number of channels. The switch fabric 600 has the same fabric layout as the switch fabric 500 . That is, the switch fabric 600 includes 8 fabric ports 610 , with first four ports (ports 0 through 3 ) operating at a speed of 1 Gb/s each, the next two (ports 4 and 5 ) operating at a speed of 2 Gb/s each, the last two ports (ports 6 and 7 ) operating at 10 Gb/s each, and the maximum data rate of a crossbar data channel being 1 Gb/s. A single 28×28 crossbar device 620 , with 28 data input channels and 28 data output channels, is used to provide switching between the fabric ports 610 . Each of the first four fabric ports ( 0 - 3 ) uses only one data channel (1 Gb/s fabric utilizes single 1 Gb/s channel) and thus one port of the crossbar (ports 0 - 3 ), each of the next two ports (ports 4 - 5 ) uses two channels (2 Gb/s fabric utilizes two 1 Gb/s channels) and thus two ports each of the crossbar (ports 4 - 5 and 6 - 7 respectively), and the last two ports (ports 6 - 7 ) each use ten channels (10 Gb/s fabric utilizes ten 1 Gb/s channels) and thus ten ports each of the crossbar (ports 8 - 17 and 18 - 27 respectively).
[0027] During each scheduling cycle, the fabric scheduler configures the crossbar device such that the data input channels are connected to the appropriate data output channels. The data is transferred at the slower of the fabric port data rates. Thus, the number of channels used for each transfer is based on the minimum of the data rates of the two fabric ports that are connected. For example, if data is transferred from
(a) input fabric port 0 (1 Gb/s) to output fabric port 5 (2 Gb/s), the input channel numbered 0 will be connected to the output channel numbered 6 (first channel associated with output fabric port 5 ), resulting in a transfer rate of 1 Gb/s, (b) input fabric port 4 (2 Gb/s) to output fabric port 6 (10 Gb/s), input channels 4 and 5 will be connected to output channels 8 and 9 respectively (first 2 channels associated with output fabric port 6 ), resulting in a transfer rate of 2 Gb/s, or (c) input fabric port 6 (10 Gb/s) to output fabric port 7 (10 Gb/s), the ten crossbar input channels numbered 8 through 17 will be connected to the ten output channels 18 through 27 pairwise, resulting in a transfer rate of 10 Gb/s.
[0031] FIG. 7 illustrates an exemplary block diagram of a fabric scheduler 700 . The fabric scheduler 700 includes a request processing block 710 , a scheduler engine 720 , a crossbar configuration block 730 , and a grant generation block 740 . The request processing block 710 receives from the fabric ports a status of their buffers 705 and generates requests 715 for the scheduler engine 720 . The scheduler engine 720 receives the requests 715 for the fabric ports and performs arbitration among them to arrive at a pairwise matching of fabric ports for transmitting data. The scheduler engine 720 provides the pairwise matches 725 to the grant generation block 740 . The grant generation block 740 generates grants 745 and communicates the grants 745 to the fabric ports, instructing them to send data to the egress port that was assigned by the scheduler engine 720 . The scheduler engine 720 also provides the pairwise matches 725 to the crossbar configuration block 730 . The crossbar configuration block 730 is responsible for configuring the crossbar devices according to the matching 725 computed by the scheduler engine 720 , so that the data arriving from an ingress fabric port on a crossbar input channel (or set of input channels) is directed to the output channel (or set of output channels) connected to the egress port.
[0032] FIG. 8 illustrates an exemplary detailed block diagram of a crossbar configuration block 800 . The cross bar configuration block 800 includes a valid destination memory 805 , a source address memory 810 , a port counter 815 , a controller 820 , a destination channel base address memory 825 , a destination channel count memory 830 , a source channel base address memory 835 , a source channel count memory 840 , a destination channel offset register 845 , a source channel offset register 850 , a destination address adder 855 , a source address adder 860 , a destination channel translation memory 865 , and a source channel translation memory 870 . The controller 820 controls the operation of the crossbar configuration block 800 .
[0033] The valid destination memory 805 is an array containing one bit for each output fabric port (destination port). The source address memory 810 is a one-dimensional array of input fabric port (source port) numbers associated with each destination port number. At the end of each scheduling period, the crossbar configuration block 800 receives from the scheduler engine the pairwise matching (results) of fabric ports based on the requests received from the ports during the current scheduling period. The results are stored in the valid destination memory 805 and the source address memory 810 . Bits in the valid destination memory 805 are active (set to ‘1’) if the scheduler engine has selected the corresponding destination port to receive data during the current scheduling cycle and is inactive (set to ‘0’) if the corresponding destination port has not been selected to receive data in the current cycle. The value stored for each active destination port in the source address memory 810 is the address of the source port that has been selected to send data (to that destination port) during the current scheduling cycle. FIG. 9 illustrates an exemplary pairwise matching result 900 for an eight fabric port switch, and the corresponding information stored in the valid destination memory 910 and the source address memory 920 . The results 900 show that there are six source to destination matches. The results 900 are mapped into the memories 910 , 920 . Each of the entries in the valid destination memory 910 is active (set to ‘1’) except ports 0 and 2 as the results 900 indicate that no data is scheduled to be transferred to those destination ports this scheduling cycle. In the source address memory 920 , the source port associated with the active destination ports is captured.
[0034] Referring back to FIG. 8 , the destination channel base address memory 825 is an array containing one value per destination port. The value stored is the address of the first output channel of the crossbar device connected to (associated with) the associated destination port. The destination channel count memory 830 is an array containing one value per destination port. The value stored is the number of output channels of the crossbar device connected to the associated destination port. The source channel base address memory 835 is an array containing one value (first input channel of the crossbar device connected to the source associated source port) for each source port. The source channel count memory 840 is an array containing one value (number of input channels of the crossbar device connected to the associated source port) per source port.
[0035] FIG. 10 illustrates contents in each of the valid destination memory 805 , the source address memory 810 , the destination channel base address memory 825 , the destination channel count memory 830 , the source channel base address memory 835 , and the source channel count memory 840 for the exemplary fabric switch 600 of FIG. 6 . The base address and count memories for both the source and destination ports contain the same information, because the number of input channels connected to a fabric port is the same as the number of output channels connected to it.
[0036] The port counter 815 is controlled by the controller 820 and steps through each destination fabric port and configures the crossbar channel or set of crossbar channels associated with each valid destination fabric port. For each port, the valid destination memory 805 indicates if the fabric port is to be connected as a destination (is valid) and the source address memory 810 provides the address of the source port to be connected to it (if applicable). If the ports are to be connected, then the first crossbar output channel to connect them is given by the value stored at location in the destination channel base address memory 825 associated with the current destination port. The first crossbar input channel is given by the value stored at the location in the source channel base address memory 835 associated with the current source port (source port to be connected to current destination port as identified by output from source address memory 810 ). The number of crossbar output channels associated with the destination port is obtained from the count value stored in the destination channel count memory 830 for the current destination port. Likewise, the number of crossbar input channels associated with the source port is obtained from the count value stored in the source channel count memory 840 for the current source port.
[0037] The destination channel base address and the source channel base address are passed through the destination address adder 855 and the source address adder 860 , respectively. The other input to the destination address adder 855 is the destination channel offset from the destination channel offset register 845 . The destination channel offset register 845 is a register containing the offset value of the current crossbar output channel being configured. The other input to the source address adder 860 is the source channel offset from the source channel offset register 850 . The source channel offset register 850 is a register containing the offset value of the current crossbar input channel being configured. These channel offset registers 845 , 850 allow cycling through the crossbar channels that need to be connected for the pair of fabric ports (destination and source). These registers 845 , 850 are initially cleared to zero, and incremented in each programming cycle until the necessary number of channels for connecting the source and destination ports have been configured. The necessary number of channels is the minimum of the counts contained in the destination channel count memory 830 and the source channel count memory 840 for the respective destination and source ports.
[0038] The output of the destination address adder 855 and the source address adder 860 can be considered logical channel numbers. Accordingly, a destination channel translation memory 865 and a source channel translation memory 870 are provided. These two memories enable the re-mapping of a crossbar logical data channel to a different data channel (physical channel). The translation memories 865 , 870 map the logical channel numbers into physical channel numbers. When the re-mapping capability from logical channel numbers to physical channel numbers is not needed, the translation memories are programmed so that the logical channel maps to the physical channel with the same number. However, the re-mapping capability is useful in a number of ways. For example, when the crossbar devices are assembled on a printed circuit board, it provides flexibility for the routing of signal traces on the board, leading to a simpler board layout. Another application of the translation memories is in dealing with crossbar channel failures. By providing a set of redundant crossbar channels, a failed channel can be remapped to one of the redundant channels using the translation memories.
[0039] The destination channel translation memory 865 outputs a destination channel number and the source channel translation memory 870 outputs a source channel number. The source channel number indicates the input data channel number of the crossbar device and the destination channel number indicates the output data channel number of the crossbar device that are to be connected. The controller 820 generates a write strobe signal that indicates when the source and destination channel numbers are valid. The write strobe signal is used to program the information into the crossbar devices. The destination channel number, the source channel number and the write strobe signal from the controller 820 constitute the configuration signals for the crossbar device.
[0040] It should be noted that the format of the crossbar configuration block and the interface signals shown in FIG. 8 are for illustration only. There are many ways of designing this configuration interface that would not depart from the current scope. For example, more than one pair of channels may be connected together with a single activation of the write strobe signal.
[0041] FIG. 11 illustrates an exemplary flowchart of the sequence of operations performed by the crossbar configuration block, according to one embodiment. For ease of understanding the flowchart will be discussed in relation to the crossbar configuration device 800 disclosed with respect to FIG. 8 . The operations in FIG. 11 are performed under the control of the controller 820 . The controller 820 could be implemented in various forms, including but not limited to, a state machine, software, and firmware.
[0042] The configuration sequence starts with initializing the port counter 815 to zero ( 1100 ). The port counter 815 contains the current destination fabric port number being processed. This value is used as the index to the valid destination memory 805 , the source address memory 810 , the destination channel base address memory 825 and the destination channel count memory 830 . A destination valid bit for the current destination port is read from the valid destination memory 805 and the corresponding source port address is read from the source address memory 810 ( 1110 ). A determination is then made as to whether the destination port is receiving data (is valid) as indicated by the destination valid bit ( 1120 ). If the bit is not active, set to ‘0’, ( 1120 No), the current destination port is not receiving data during the current scheduling cycle and the port counter 815 is incremented by 1 ( 1190 ).
[0043] If the destination port is valid ( 1120 Yes), the destination channel count associated with the current destination port is read from the destination channel count memory 830 and the source channel count associated with the source port to be connected (source port address associated with destination port address in the source address memory 810 ) is read from the source channel count memory 840 ( 1130 ). The destination and source channel count values provide the number of crossbar channels connected to the destination and source fabric ports respectively. The minimum of the source and destination channel counts is calculated and stored in a variable count ( 1140 ). This value represents the number of distinct crossbar channel pairs that need to be configured to connect the current pair of destination and source ports.
[0044] The destination channel offset register 845 and the source channel offset register 850 are cleared, set to zero ( 1150 ). The destination channel base address provided from the destination channel base address memory 825 and the output (destination channel offset) of the destination channel offset register 845 are sent to the destination address adder 855 . The destination address adder 855 uses the destination channel offset as an offset to compute the destination channel number by adding it to the destination channel base address. Similarly, the source channel base address is provided from the source channel base address memory 835 and the source channel offset of the source channel offset register 850 are sent to the source address adder 860 . The source address adder 860 uses the source channel offset as an offset to compute the source channel number by adding it to the source channel base address. The output of the destination address adder 855 provides the current channel number for the crossbar output channel to be configured, and the output of the source address adder 860 provides the current channel number for the crossbar input channel to be configured. These channel numbers pass through the respective translation memories 865 , 870 and appear as output signals of the crossbar configuration block 800 . When the values of the output and input channel numbers appear at the respective outputs, the values are loaded into the crossbar device by activating the write strobe signal ( 1160 ).
[0045] After the current pair of channels have been configured, both the destination channel offset register 845 and the source channel offset register 850 are incremented by one to point to the next output channel and input channel, respectively ( 1170 ). The count variable is then decremented by 1, ( 1180 ), and a determination is made as to whether the count is greater than 0 ( 1185 ). If the count is greater than 0 ( 1185 Yes), more channels remain to be configured for the current pair of fabric ports, and the process returns to 1160 where the next pair of channels for the current pair of fabric ports is configured.
[0046] If the count is found to be 0 ( 1185 No), all channel pairs of the current port pair have already been configured. The port counter 815 is incremented by 1 to point to the next destination fabric port ( 1190 ). A determination is then performed to determine if all the ports have been processed. In order to determine if the last port has been processed a determination is made as to whether the port counter is less than N, the total number of ports ( 1195 ). If the value of the port counter 815 is less than N ( 1195 Yes), more fabric ports remain to be configured and the operations returns to 1110 . If the value of the port counter 815 is not less than N ( 1195 No) the process ends. If the last port (N-1) was processed and then incremented by 1 in 1190 , the 1190 determination will be No and the process will end.
[0047] The process defined above with respect to FIG. 11 is in no way limited thereto. Rather, the process could be modified in numerous ways (e.g., order, arrangement) without departing from the scope.
[0048] It should be noted that the process defined in FIG. 11 only connects the fabric ports that are transmitting data and does not connect the fabric ports that are not transmitting data. Moreover, if two fabric ports of different speeds are connected there will be channels associated with the higher speed fabric port that are not connected. However, in some fabric systems, it is necessary to connect all the data output channels of the crossbar devices to data sources even when the channel does not take part in a data transfer during the current period. This may be necessary to preserve synchronization on the receive side of the fabric ports, or because of electrical considerations. This requirement can be satisfied by connecting all the crossbar output channels that do not participate in a data transfer in the current cycle to one of the input channels that does not participate in the data transfers.
[0049] The connection of unused (idle) output channels to unused (idle) input channels can be completed at the end of the process defined in FIG. 11 . Alternately, this feature can also be integrated into the operations of the process of FIG. 11 by connecting any unused output channels to any unused input channel as each destination port is processed.
[0050] Although the various embodiments have been illustrated by reference to specific embodiments, it will be apparent that various changes and modifications may be made. Reference to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” appearing in various places throughout the specification are not necessarily all referring to the same embodiment.
[0051] Different implementations may feature different combinations of hardware, firmware, and/or software. For example, some implementations feature computer program products disposed on computer readable mediums. The programs include instructions for causing processors to perform techniques described above.
[0052] The various embodiments are intended to be protected broadly within the spirit and scope of the appended claims.
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In general, in one aspect, the disclosure describes a switching device that includes a plurality of ports. The ports operate at asymmetric speeds. The apparatus also includes a switching matrix to provide selective connectivity between the ports. The apparatus further includes a plurality of channels to connect the ports to the switching matrix. The number of channels associated with each port is determined by speed of the port.
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BACKGROUND OF THE INVENTION
1. Scope of Invention
This invention relates generally to a method and apparatus for folding a sheet of paper which is continuously moving in a single plane.
2. Prior Art
Heretofore it was necessary to momentarily stop the lateral movement of a sheet of paper in order to form a fold. One common type of folding mechanism is a buckle folder wherein the leading edge of the sheet is fed into a pocket causing the adjacent portion to buckle and to be fed into the bite of adjacent folding rolls. Another type of folder is the blade type when the sheet is passed over a pocket and a blade operates to push a portion of the sheet into the pocket to form a fold. In both prior-known types of folding, the forward or feeding motion of the sheet has to be momentarily stopped while the fold is being formed.
My previous U.S. Pat. No. 4,310,325 provides a method and apparatus for folding a sheet of paper without interrupting the path of movement and the continuous feeding motion of the sheet. This is important to increase the folding speed of the sheets. Each folded portion of the sheet is retained in its folded position while the additional folds are sequentially formed. However, in this previous patent, the speed of this apparatus and method were limited due to the fact that only one sheet would be raised and folded for each revolution of the sheet folding mechanism, it having a pair of spaced apart single excentrically mounted pulleys. Based in part upon other significant improvements by applicant in signature folding sequencing as taught in another of my previous U.S. Pat. No. 5,655,866, a substantially higher sheet folding rate is now a desired feature not offered by current technology.
BRIEF SUMMARY OF THE INVENTION
An apparatus for sequentially forming folds in a sheet of paper which is continuously moving substantially in a single plane. A first fold is formed in the center of the continuously-moving sheet of paper and subsequent pairs of folds are sequentially formed, one on each side of the previously-formed folds, until the entire continuously-moving sheet is folded. Guide wires retain each folded section until the entire sheet is folded by the cyclic upward movement of a continuous flexible wire loop held for free movement on a pair of spaced apart pulley assemblies. Each pulley assembly includes a plurality of evenly spaced pulleys each of which are held for free rotation on a rotatable support frame. Each support frame is driven in rotation about a central axis thereof. Each individual pulley includes a freely rotatable ring surrounding the periphery of the pulley around which the flexible wire loop is held.
One object of this invention is to form folds in a sheet of paper at higher fold rates while the sheet is moving in a predetermined path.
Another object is to sequentially form folds in a sheet of paper which is moving in a predetermined path.
Another object of this invention is to sequentially form folds in a sheet of paper which is continuously moving in a predetermined path at higher rates of speed and wherein the folded portions are retained in folded position until the entire sheet is folded.
A still further object of this invention is to accurately fold a sheet of paper into sections at a higher rate of speed.
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 7 are taken from my prior U.S. Pat. No. 4,310,326.
FIG. 1 is a schematic drawing showing the sequential folding of a sheet at four operating stations.
FIG. 2 is a fragmentary top plan view of the folding apparatus taken on lines 2--2 of FIG. 3.
FIG. 3 is a cross-sectional view of the sheet-folding mechanism taken on line 3--3 of FIG. 4.
FIG. 4 is an end-elevational view showing Station I in solid lines which is fully illustrated in FIG. 3, and Stations II and III in dotted lines.
FIG. 5 is an enlarged cross-sectional view taken on line 5--5 of FIG. 3 showing the folded portion of the sheet of paper as it leaves Station I and being retained by guides 36, 37 and fold guide 39.
FIG. 6 is an enlarged fragmentary section of folding mechanism pulley and fold wire.
FIG. 7 is an enlarged cross-section showing the inter-relationship between the folding wire, the folded portion of sheet and the folding rollers.
FIG. 8 is a perspective simplified schematic view showing the present invention sequentially folding sheets of paper such as signatures used in book binding.
FIG. 9 is a side elevation simplified schematic view of the sheet folding mechanism of the invention within a system for feeding, folding and ejecting sheet signatures and book covers.
FIG. 10 is an enlarged view of the sheet folding mechanism of FIG. 9 and also showing an alternate and preferred form of a magnetic sheet feeding mechanism.
FIG. 11 is a view similar to FIG. 10 showing an alternate terminal position of the sheet feeding mechanism.
FIG. 12 is a simplified diagrammatic view of one portion of the sheet folding mechanism showing the sequential movement thereof.
DETAILED DESCRIPTION OF THE INVENTION
Related Prior Art
Referring now to the drawings, FIGS. 1 to 7 describe my closely related prior U.S. Pat. No. 4,310,326. FIG. 1 therein shows a schematic drawing of the folding operations performed on each sheet of paper fed into the folder. As shown, a sheet of paper is fed flat into the folder and while in substantially continuous motion, a first fold is formed in the sheet at station 1. The sheet continues to move and while in motion two more folds are formed, one on each side of the first fold at station II. The sheet continues to move and two more folds are formed, one at each end of the previously formed folds at station III. The completely folded sheet is then laid on its side. At this point, as shown, the folded sheet is subjected at station IV to two more folds which are at right angles to the original folds.
FIG. 3 shows a side elevation of the novel sheet-folding mechanism 1. This mechanism 1 comprises a pair of spaced-apart pulleys 2, each of which is eccentrically mounted to its respective shaft 3 which in turn is mounted in its respective support 4 each of which is secured to the undersurface of the table surface 5. A continuous braided wire 6 tightly extends around and between both pulleys 2. A sprocket 7 is secured to each pulley shaft 3 and a timing belt 8 extends over each sprocket 7 and over a sprocket 9 connected to the drive shaft of a motor 10 mounted to the base of the machine. The sheet-folding mechanism 1, comprising the pulleys 2 and the wire 6, is driven in an elliptical path 11 (shown in dotted lines) by the motor 10.
An opening 12 is formed in the table surface 5 having a width and length sufficient to permit the passage and the movement of the folding mechanism 1. In operation, the wire 6 contacts the sheet 13 and pulls it upwardly with its movement. Thus the length of the fold formed in the sheet of paper is equal to the distance that the folding mechanism travels above the table surface 5. It should be understood that the folding mechanism 1 may be adjustably mounted to the undersurface of the table surface 5 so that the distance that it moves above the surface of the table surface 5 can be adjusted to form the desired length of the fold to be formed in the sheet.
As shown in FIG. 3, a paper-ejecting mechanism comprises a plurality of driven rollers 16 and an axle 20 for each roller is mounted in a slot 17 formed in a yoke 18 for each roller. A spring 19 is mounted in each slot 17 to retain the axle 20 of each roller 16 under pressure at the bottom of each slot 17. The yokes 18 are secured to a frame 21 which is secured to upwardly-extending supports 22. The upper end of supports 22 are adjustably secured to the upper machine frame 23. The rollers 16 are positioned so that they will contact the wire 6 when the folding mechanism 1 is at the uppermost reach of its elliptical path.
FIG. 6 is an enlarged, fragmentary, cross-sectional view showing the detailed construction of a pulley 2 and a roller 16 and the interaction of the pulley 2, the wire 6, the folded paper 13 and the roller 16 at the time that the folding mechanism is at the uppermost reach of its elliptical movement. As shown, each pulley 2 is constructed of a pair of outer discs 24 with the outer surfaces of the peripheral edge having an inwardly-tapered surface 25 extending to a point. The inner core 26 of the pulley has a diameter smaller than the diameter of the discs 24. The outer edge of the pulley core 26 has a roller bearing raceway 27 for receiving a plurality of roller bearings 28. An outer ring 29 having a roller bearing raceway 30 in its inner surface is positioned to contact the roller bearing 28 and extends slightly beyond the periphery of the disc members 25. The outer surface of ring 29 has a concave surface 32 for receiving the braided wire 6. Thus it can be seen that the wire 6 has a rotational movement about the pulleys 2 independent of and in addition to the elliptical movement that it has as it is carried along with the movement of the eccentrically mounted pulleys 2.
As further shown in FIG. 7, each of the driven rollers 16 are formed having their outer periphery formed into outwardly extending legs 32. It is to be understood that FIG. 7 shows the parts enlarged with the pulley 2 at the uppermost reach of its eccentric movement and the wire 6 in contact with the spring-loaded roller 16 which is rotated at a high speed. At this point, the folding mechanism 1 is at its highest point of elliptical movement and the wire 6 has contacted and lifted a portion of sheet 13 away from table 2. Since the high-speed roller 16 is spring loaded, the net effect is to slightly lift the sheet from the wire 6 and to form a slight crease.
Referring to FIG. 3, the solid lines show the folding mechanism at the uppermost reach of its elliptical path. Since the rollers 16 confine the paper between the peripheral surfaces 32 of the rollers 16 and the wire 6 and since the rollers 16 are spring loaded, a downward pressure is applied to the upper reach of wire 6. To assure that the upper reach of wire 6 remains tight, it is desirable to place a wire-tensioning means on the lower reach of the wire 6. This tensioning means takes the form of a pair of grooved pulleys 33 freely rotatably mounted in the upper end of yokes 34. A spring member 35 is secured at one end to the lower end of each yoke 34 and fixed at its lower end to the base of the machine. Thus, as shown in FIG. 3, the solid lines show the springs 35 under maximum tension, and thus exerting maximum tension of wire 6, when the folding mechanism is in the uppermost reach of its elliptical path and under minimum tension when the folding mechanism 1 is at the lowermost reach of its elliptical path as shown in the dotted lines.
It is important to retain the portion of the sheet which is not subject to the folding action of the folding mechanism in the plane of the table surface 5. This is accomplished by providing guide rods 36 and 37, one on each side of slot 12 in the table surface 5. These guide rods 36 and 37 are retained in a position slightly above table surface 5 a distance sufficient to allow free passage of the sheet by means of vertical supports 38 which are adjustably secured at their upper ends to the upper machine frame 23. As the wire 6 of the fold mechanism 1 contacts the sheet 13 and moves the contacted portion of the sheet upward, each side of the sheet is pulled around the guide rods 36 and 37 and the remaining portion of the sheet. As shown in FIG. 3, a fold guide 39 is positioned at the forward end of the table surface opening 12 and is retained at the same distance above the table 5 as the upward movement of the folding mechanism 1 by supports 40 which are in turn secured to the top of table 5. The guide rods 36 and 37 and fold guide 39 extend the length of the fold machine to control the sheet at the top and bottom of each fold.
As seen in FIG. 3, each sheet 13 is fed onto the table 5 in the direction shown by arrow 14 by dogs 41 which contact the rear edge of the sheet 13. The dogs 41 are secured to a conventional chain drive which extends beneath and at each side of the table surface 5 to a point approximately at the forward end of opening 12. Dogs 41 are spaced on the chain drive at a distance greater than the width of each sheet so that the sheets are fed onto table 5 and into the folding mechanism 1 one after the other.
FIG. 3 illustrates the folding mechanism and operation that takes place at station 1. A sheet 13 is fed onto the table and as it passes through opening 12 the folding mechanism moves in its elliptical path and wire 6 contacts the sheet and raises it and at the same time pulls the sheet around guide rods 36 and 37. As the folding mechanism 1 reaches the uppermost limit of its elliptical path, a portion of the paper which is folded over wire 6 contacts the rollers 16 which are rotating rapidly at about 2,000-3,000 revolutions per minute and the entire sheet 13 is rapidly driven forward and the upper folded portion is driven onto fold guide 39. The forward movement of the sheet 13 is so rapid that the contact of the sheet between rollers 16 and wire 6 and the driving of the upper fold portion of tile sheet onto the fold guide 39 takes place during the small period of time that the folding mechanism 1 is at its uppermost reach in its elliptical path. The elliptical movement of the folding mechanism 1 and the movement of the sheet-feed dogs 41 are coordinated so that, as each succeeding sheet 13 is fed onto the table surface 5 and over opening 12, the folding mechanism 1 is again starting its upward movement through opening 12.
Station II is located adjacent to Station I and comprises two folding mechanisms 1' which are identical to folding mechanism 1 and which are located one on each side of guide rods 36 and 37 and fold guide 39 as best seen in FIGS. 2 and 4. Each of these folding mechanisms 1 has additional guide rods 36' and 37' to complement guide rods 36 and 37 but which start at Station II and extend to the end of the machine. Each folding mechanism 1' also has its own fold guide 39' which, like fold guide 39 at Station I, is positioned at the end of table opening 12 and extends from that point to the end of the machine. The folding mechanisms 1' operate in tandem in the same manner as the folding mechanism 1 at Station I.
As the sheet 13 is fed from Station II and into Station III, it now has three upwardly extending folds. Station III comprises two folding mechanisms 1' which are identical to folding mechanism 1 and which are located one on each side of guide rods 36" and 37" to complement guide rods 36' and 37' but which start at Station III and extend to the end of the machine. Each folding mechanism 1" has its own fold guide 39" which, like fold guides 39 and 39', is positioned at the end of its table opening 12 and extends from that point to the end of the machine. Throughout its passage through the folder, the folds in the sheet 13 are maintained by the guide rods 36, 37, 36', 37', 36", and 37" and by the fold guides 39, 39' and 39". As the folded sheet is fed from Station III it is fed off the guide rods and fold guides and between a pair of conventional vertically-extending rollers 51 as seen in FIG. 1 which compress the folds further and allow the folded sheet to lie flat on the table surface after turning. At that point the folded sheet can be removed or, if desired, the same folding mechanism can be used to fold the folded sheet at right angles to the original folds at a Station IV.
It is to be understood that the guide rods 36 and 37 and fold guide 39 at each station can be adjusted for various paper thicknesses and widths of folds. The speed of elliptical movement of the folding mechanism 1 and the rotational speed of cooperating rollers 16 can be adjusted for the type and weight of paper being folded. It may also be desirable, under some operating conditions, to provide added feeding rollers 50 which cooperate with the fold guide 39 to assist in moving each sheet 13 from one station to the next. Other adjustments of parts and speeds of operation may be made to accommodate the type of material being folded without departing from the spirit and scope of the invention. Additionally, at the end of Station III, sheet metal elements may be provided at each side of the folding mechanism to guide the leading edge of the folded sheet into the rollers 51. After the folded sheet has been folded at Station IV glue may be applied to one folded edge for perfect binding. If desired, a plurality of sheets 13 which have been folded at Station IV may be grouped together and glue applied to one edge for perfect binding. It has been found that, when the disclosed folding method is utilized and the folded sheets perfect bound, a paper saving of as much as 8 percent can be achieved.
The Invention
Referring now to the drawings, FIGS. 8 to 12, the improved folding mechanism of the present invention is shown generally at numeral 60 in all figures. This improved folding mechanism 60 includes a pair of spaced apart pulley assemblies 62, each of which is mounted centrally thereof to each respective mounting shaft 66 and 68 via a triangular frame 82 of each of the pulley assemblies 62. Each respective shaft 66 and 68 is, in turn, connected beneath a table surface 81 previously described in FIGS. 3 and 4.
A continuous braided wire 74 tightly extends around and between both pulley assemblies 62. A sprocket (not shown) is secured to each shaft 66 and 68 and a timing belt (not shown) extends over each of the sprockets and over another sprocket connected to a drive shaft of a motor (not shown) mounted to the base of the machine as previously described in FIG. 3. Thereby, the sheet folding mechanism 60, comprising the pulley assemblies 62 and the wire 6, is driven by the motor (not shown) as previously described.
An elongated opening similar to that shown at numeral 12 in FIG. 2, is formed in the table surface 81 having a width and length sufficient to permit the passage and the movement of the folding mechanism 60 therethrough. In operation, as previously described, the wire 74 contacts each sheet 13 and pulls or lifts it upwardly with corresponding movement of the wire 74 as best shown in FIG. 12. When each pulley assembly 62 rotates about shaft 66 in the direction of arrow D as each sheet 13 is being fed into the folding mechanism in the direction of arrow A, the wire segment 74a shown in solid lines moves toward the position shown in phantom at 74b. This wire movement starts the folding process of each sheet 13 as each of the pulley assemblies 62 rotate in unison further into the maximum vertical positioning of the wire at 74c.
Thus, the length of the fold formed in the sheet of paper 13 is equal to the distance that the folding mechanism 60 travels above the table surface 81 as previously described. Adjustability is also provided in the vertical positioning of the folding mechanism 60 so as to vary the length to be formed in each sheet 13 again as previously described.
A paper-ejecting mechanism similar to that shown in FIG. 3 comprises a plurality of driven rollers 16 each mounted on a separate axle 20. These rollers 16 are positioned so as to contact the wire 74 when the folding mechanism 60 is at its uppermost reach shown in phantom in FIG. 12. Each of the pulleys 64 is mounted on frame 82 for free rotation about separate shafts 106 and structured in function similar to that shown in FIG. 6. Thus, the outer edge of each of the pulleys 64 are structured as shown at 29 in FIG. 6 to receive the braided wire 74 and to rotate independently with respect to the central main portion of each pulley 64. Referring back to FIG. 7, each of the driven rollers 64 is similarly formed having the outer periphery thereof formed into outwardly extending legs 32 which enhance the folding process of each sheet 13.
To insure that the upper reach of wire 74 remains tight, as previously described, it is desirable to place a wire tensioning means on the lower reach of the wire 74 as shown and described in FIG. 3. It is also important in the present invention to retain a portion of each sheet 13 which is not subject to the folding action of the folding mechanism 60 in the plane of the table surface 81. This is accomplished in a fashion similar to that previously described by providing guide rods 79 one on each side of the folding mechanism clearance slot (not shown) formed into the table surface 81. These guide rods 79 function as previously described in FIGS. 2,3 and 5. The fold guide rod 76 is positioned at the forward end of the table surface 81 and is retained at the same distance above the table surface 81 as is the maximum upward positioning of the wire 74 of the folding mechanism 60 by supports connected to the table surface 81. The fold guides 79 receive the folded sheet of paper ejected by the driven pulleys 16 and may be assisted in moving each folded sheet 13 from one station to the next by feed rollers 50, again as previously described.
Referring to FIG. 9, one embodiment of a signature folding apparatus is there shown generally at numeral 80 and includes the previously described folding mechanism 60. This apparatus 80 includes an endless feed belt 84 which feeds signatures in sequential order without the last fold formed in the direction of arrow F. A stacking drum 86 receives each of the partially folded sheets 13, applies glue at 90 as each of the sheets passes in the direction of arrow G onto one stack thereof. Covers 88 are likewise sequentially stacked by another stacking gum 92 as glue is also applied at 90. As the feed belt 94 with dogs 96 is moved in the direction of arrow A, the respective sequence of partially folded signatures 13 and partially folded covers 88 are fed onto the folding mechanism 60 in the direction of arrow J for the final folding operation.
Alternate similar sheet feed mechanisms are shown in FIGS. 10 and 11. These sheet feed mechanisms include two opposed continuous belts 98 each of which have spaced apart thin magnets 100 attached thereto. As the magnets 100 are centrally between the two closely spaced feed belts 98 at 99 with each sheet 13 clampingly retained therebetween, sufficient sheet clamping force allows the fold to start to take place on the moving wire 74 of the folding mechanism 60 until the guide rods 79 take over to engage and retain a portion of the sheet to complete fold. In the arrangement of FIG. 10, the feed belts 98 terminate at 102 while overlapping the folding mechanism 60 for insured fold tightness and retention of unfolded portions of each sheet against the table surface 81. In this embodiment, a magnetized wire driving device 104 producing a substantially continuous driving force M on wire 74 (which is made of a magnetic material) is utilized in lieu of the wire driving motor previously described. This wire driving device 104 assists in driving the wire 74, the other driving forces being the rotation of each of the pulley assemblies 62 and rotation of the driven rollers 16 against the wire 74 to eject the folded signatures 13. A compression spring 105 in FIG. 10, or the like, acting against each shaft 66 and 68 is preferred to maintain a separating biasing force between the pulley assemblies 62.
The magnetic feed belts 98 in FIG. 11 are similar to that shown in FIG. 10 except that the end 1 02a of the feed belts 98 terminate short of the folding mechanism 60 wherein the guide rods 79 extend further rearwardly to insure that each sheet 13 is held tightly against the table surface 81 except as controlled by the lifting and folding action of the folding mechanism 60.
As shown in FIG. 8, a perforation assembly may be included as shown at numeral 70. The usefulness of perforating these sheets along the intended fold line has been established in another of my co-pending U.S. patent applications which substantially improves the bonding strength of the binding edge of each book. Thus, each sheet 13 moving into the folding mechanism 60 in the direction of arrow A is initially perforated along the intended fold line prior to being sent into and folded by the folding mechanism 60 as previously described.
A primary benefit of the of the present invention over my prior U.S. '326 patent is speed. Whereas my previous folding mechanism 1 provided one fold per revolution of the pulleys 2 about an eccentrically located shaft, the present invention will provide a plurality of folds per each revolution of each of the pulley assemblies 62 of the folding mechanism 60 itself. Although three pulleys 64 per pulley assembly 60 appear to increase folding speed to an ideal fold rate at this time, nonetheless the use of two pulleys, four, five or more may be utilized in each of the pulley assemblies so that a corresponding number of folding movements of the tensioned folding wire achieved for each revolution of each of the pulley assemblies. Although with increasing numbers of pulley wheels per pulley assembly, the upward throw of the folding wire is decreased, it is believed that this may be compensated both by the vertical positioning of the folding mechanism with respect to the table surface 81 and with respect to variations in the paper feed arrangement into the folding mechanism with the addition of slanted guide plates or wires (not shown).
While the instant invention has been shown and described herein in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be afforded the full scope of the claims so as to embrace any and all equivalent apparatus and articles.
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An apparatus for sequentially forming folds in a sheet of paper which is continuously moving substantially in a single plane. A first fold is formed in the center of the continuously-moving sheet of paper and subsequent pairs of folds are sequentially formed, one on each side of the previously-formed folds, until the entire continuously-moving sheet is folded. Guide wires retain each folded section until the entire sheet is folded by the cyclic upward movement of a continuous flexible wire loop held for free movement on a pair of spaced apart pulley assemblies. Each pulley assembly includes a plurality of evenly spaced pulleys each of which are held for free rotation on a support frame. Each support frame is driven in rotation about a central axis of rotation. Each individual pulley includes a freely rotatable ring surrounding the periphery of the pulley around which the flexible wire loop is held.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hydrophilic plastic materials useful as soft contact lenses and, more particularly, relates to hydrophilic copolymers and to their preparation and use, which compositions are extremely resistant to clouding and/or discoloration in use.
2. The Prior Art
As is already known, compositions adapted for use as soft contact lenses have been developed from hydrophilic-type polymers which are softer and more easily accommodated by the eye then are the earlier hydrophobic-type polymers such as polymethyl methacrylate and the like. Hydrophilic polymers may be defined typically as lightly cross-linked, essentially water-insoluble copolymers derived from one or more monomers containing hydroxy groups for imparting to the polymers their affinity for water. These polymers may further be defined as coherent, 3-dimensional polymer structures or networks which have the ability to absorb or imbibe water, even in large quantities, e.g., up to 90 weight %, without dissolution. When containing water in any amount whatsoever, a hydrophilic polymer will expand correspondingly and, in its hydrated state, correctly may be designated as a hydrophilic polymer "gel," or "hydrogel." A specific class of polymer hydrogels which have gained particular commercial acceptance as soft contact lenses are those derived from acrylic esters. U.S. Pat. Nos. 2,976,576 and 3,220,960 issued to O. Wichterle and D. Lim on Mar. 28, 1961, and on Nov. 30, 1965, respectively, are early patents which describe the use of methanol-insoluble hydrophilic acrylic ester polymer materials for the manufacture of soft contact lenses.
Acrylic ester hydrophilic polymers, for the most part, are derived by copolymerizing a mixture containing a major amount of a water-soluble monoester of acrylic or methacrylic acid in which the ester moiety contains at least one hydrophilic group, and a minor amount of a bifunctional diester of acrylic or methacrylic acid which cross-links the hydrophilic group-containing monomer as it polymerizes. The degree and type of cross-linking in the resulting polymer governs, to a large extent, its maximum water content, when fully hydrated.
Although accommodated much more comfortably by the wearer than the prior hard contact lenses, presently known soft contact lenses, as prepared from the aforedescribed polymer hydrogels, do have disadvantageous properties and have not been completely satisfactory. Hydrogel lenses favor the growth of pathological bacteria and fungi on their surfaces. If not regularly cleaned and sterilized or if they are stored in contaminated solutions, pathogens can be easily absorbed by the lens materials due to their flexible, hydrophilic polymer structure. Also, because of their aforesaid flexible, hydrophilic polymer structure, proteins and other normal substances in the eye environment can be easily diffused through the lenses with use. Accumulation of such substances in a soft contact lens causes its discoloration and clouding with repeated cleaning and sterilization techniques practiced by the wearer. Too, the lenses can lose sufficient amounts of water during use to deleteriously affect their dimensional stability and optical acuity.
It is an object of this invention, therefore, to provide a soft contact lens which is resistant to penetration by pathological organisms and chemicals damaging to the eye.
It is another object of this invention to provide a hydrophilic lens polymer which is sufficiently resistant to the diffusion of proteins and other migratory eye substances to prolong its life and optical effectiveness significantly.
It is yet another object of this invention to provide a soft contact lens which will retain a sufficient quantity of water during use to maintain its dimensional stability and optical acuity.
SUMMARY OF THE INVENTION
The present invention is directed to novel hydrophilic copolymers adapted to the fabrication of desirable soft contact lenses, which copolymers contain a major portion of polymerized units of an hydroxyalkyl acrylate or methacrylate monomer with a minor portion of a nitro-substituted aryl acrylate or methacrylate monomer, and optionally with a minor amount of a further monomer. The further monomer may be present either as an impurity in the primary constituents of the copolymerization mixture or may be specifically added, e.g., to provide cross-linking sites for the developing polymeric chains from said primary monomer reactants. Without adding any significant amount of additional monomer in the copolymerization process, or without any modification of the surface of said copolymer products when shaped into lenses, the copolymer obtained herein is found to be extremely resistant to protein diffusion therethrough, thus exhibiting less clouding and discoloration in use by comparison to other acrylic ester-type hydrophilic polymer lenses in commerce at this time.
BRIEF DESCRIPTION OF THE DRAWING
Other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawing, FIG. 1. This drawing is a graph wherein the average disintegrations per minute (dpm) of lens samples fabricated from a copolymer product of this invention are plotted against the number of days these samples are stored in simulated tear solution containing 3 H-lysozyme, compared to those exhibited by similarly tested lenses fabricated from an hydroxylethyl methacrylate (HEMA) homopolymer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The terms "polymer" and "copolymer" as used herein in the specification andclaims in defining the hydrophilic, water-insoluble products of this invention refer to a macromolecular substance which has been produced by polymerizing two principal comonomers, although such product may incidentally contain polymerized units of one or more additional known monomers in minor amounts, for purposes such as cross-linking, increasing the wettability of soft contact lens products fabricated therefrom, or otherwise.
Likewise, as used herein in the specification and claims, the terms "hydrogel" and "polymer hydrogel" are each intended to refer to a shaped hydrophilic polymer, e.g., a soft contact lens, which contains imbibed water in an amount ranging generally from less than 1% to 90% by weight ofa shaped polymer. However, it is well recognized that to be completely comfortable to the eye, soft contact lenses for practical application normally contain at least about 25% water, preferably about 30% water, andstill more preferably about 35% water, by weight. Accordingly, polymer hydrogels described herein as fabricated from the hydrophilic polymer products of this invention are those containing at least about 25% water by weight.
As previously stated, the hydrophilic copolymers of this invention are obtained by the simultaneous polymerization and cross-linking, in the presence of a free radical polymerization catalyst, of a mixture of:
(a) a hydroxy containing acrylate or alkacrylate;
(b) a nitro-substituted aryl acrylate or methacrylate; and optionally
(c) a cross-linking agent.
The hydroxy containing acrylates and alkacrylates and which are used in thecopolymerization as component (a) may be represented by the structural formula: ##STR1##wherein R represents hydrogen or alkyl of from 1 to about 6 carbon atoms; R' represents hydrogen or alkyl of from 1 to about 6 carbon atoms, preferably hydrogen, methyl or ethyl; and n is an integer of 1 to about 6.Such hydroxy containing acrylates and alkacrylates and may correctly be called glycol and polyglycol monoacrylates and monoalkacrylates. They are well-known in the art and may be obtained by the alkoxylation of an alpha-methylene carboxylic acid, e.g., acrylic or methacrylic acid, with avicinal alkylene oxide, such as ethylene oxide, propylene oxide or the like, until the desired amount of alkylene oxide has been reacted with thealpha-methylene carboxylic acid. Specific hydroxyalkyl acrylates and alkacrylates suitably employed as component (a) of the polymerization mixture include hydroxyethyl methacrylate (HEMA), hydroxypropyl acrylate (HPA), and hydroxypropyl methacrylate (HPMA). Normally, these monomers comprise at least about 93% by weight of the reaction mixture and of the copolymer product prepared. Percentages of the monomers preferred at present are from about 94% to 99.4%, by weight of the reaction mixture andproduct, with percentages ranging from 98% to 99.4% being the most preferred. The particular monomer presently preferred is hydroxyethyl methacrylate (HEMA).
The monomer used herein as component (b) of the copolymerization reaction mixture specifically is para-nitrophenyl methacrylate. This compound has the formula: ##STR2##Units from this monomer generally may comprise only up to about 7% by weight of the reaction mixture and the prepared copolymer. Preferably, this monomer comprises from about 0.6% to 6% and still more preferably about 0.6% to 2% by weight of the reaction mixture and product.
As the optional component (c) of the copolymerization reaction mixture, i.e., the cross-linking agent, there may be used an alkylene glycol diacrylate or dimethacrylate, represented by the formula: ##STR3##wherein R represents hydrogen or alkyl of 1 to 4 carbon atoms, and n is an integer of from 1 to about 20, preferably of from 1 to 4. As examples thereof may be mentioned ethylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol diacrylate or dimethacrylate, and the like. Ethylene glycol dimethacrylate is the presently preferred difunctional cross-linking agent. When employed, this component normally is incorporated in extremely minor concentrations, i.e., from about 0.10% to 0.99% by weight of the polymerization mixture.
Preparation of the copolymers herein may be effected by various techniques known in the art. The process may be carried out by bulk polymerization ofthe comonomer mixture in the presence of a free radical polymerization catalyst, such as any of the well-known inorganic or organic peroxy compounds. These catalysts may be employed in the range of about 0.05% to about 2% by weight of the monomer components. Typical catalysts include lauroyl peroxide, benzoyl peroxide, isopropyl percarbonate, azobisisobutyronitrile (AIBN) and known redox systems such as the ammoniumpersulfate-sodium metabisulfite combination and the like. Irradiation such as by ultraviolet light may also be employed to catalyze the copolymerization reaction.
The copolymerization reaction generally is carried out at temperatures ranging between room temperature and 90° C., with temperatures of 50°-70° C. being preferred.
The copolymerization is advantageously carried out in bulk by preparing thecomonomer mixture, adding the required quantity of free radical initiator thereto and then conducting the reaction in a sealed vessel at the selected temperature. According to presently preferred practice, the reaction mixture, after preparation, is cast into a depression on the upper surface of a glass plate. The glass plate is then covered with another having a similar depression on its lower surface. When positioned,the depression on the underside coincides with that of the lower plate to form a reservoir wherein copolymerization is effected upon heating the plate assembly at the desired reaction temperature. The reaction is conducted for a time period of 10-16 hours, depending upon the amount of reaction initiator employed, the relative proportions of the monomers and the nature of any solvent employed.
Alternatively, the reaction may be carried out in the presence of water-soluble solvents in which the monomer components are soluble. Suitable solvents include the lower aliphatic alcohols, dioxane, ethylene glycol, glycol esters or ethers, etc. When employed, the solvent will be present in the reaction medium in about equivalent volumetric proportions to the hydroxyalkyl methacrylate monomer. Upon completion of the reaction,the organic solvent may be removed by washing the reaction mixture with water, by distillation or by other known recovery procedures.
When employing an organic solvent, films may be formed by casting the copolymer solution onto a smooth surface, then drying and stripping the copolymer film therefrom. Also, polymeric products having a predetermined shape may be obtained by casting techniques using molds of the desired shape.
For a fuller understanding of the nature of this invention, the following examples are given but are not to be taken in a limiting sense. Unless otherwise indicated, all parts and percentages given are by weight.
EXAMPLE 1
A. Preparation of hydroxyethyl methacrylate/p-nitrophenyl methacrylate copolymer.
Para-nitrophenyl methacrylate (p-NO 2 .0.MA), 0.3 g, was dissolved in asolution of 15 ml (16.1 g) of hydroxyethyl methacrylate (HEMA) in 15 ml of ethylene glycol, providing a solution containing about 2% pNO 2 .0.MA by weight of total monomer. To the resulting solution were added 0.2 ml each of a 6% ammonium persulfate solution and a 12% sodium metabisulfite solution by weight. The polymerization mixture was then cast between glassplates, 33/8 inches square. The plate assemblies were heated in an air-circulating oven maintained at 65° C. for 17-18 hours. After cooling, the clear copolymer films were removed from the plate assemblies (Sample 1A). As a control, films of HEMA homopolymer were prepared as described above, excluding pNO 2 .0.MA from the reaction mixture (Sample 1B). All films were equilibrated and stored in physiological saline solution. Duplicate sets of both the HEMA homopolymer discs and theHEMA-pNO 2 .0.MA copolymer discs were then treated with radioactive ethylenediamine ( 14 C-EDA) at 60° C. for 2 hours, after whichthey were stored in saline solution. Discs of untreated HEMA were likewise stored in saline solution as controls.
After storage for 5 days, duplicate discs of both the 14 C-EDA-treatedHEMA homopolymer and the 14 C-EDA-treated HEMA-pNO 2 .0.MA copolymer were removed and placed in scintillation fluid for counting of labeled EDA. Samples of the untreated HEMA were also placed in scintillation fluid for checking radioactivity. This procedure was repeated after the discs had been stored in saline for 9 days. The following results were obtained, the values obtained for untreated HEMA homopolymer deemed to be due to background and quenching effects of the scintillation fluid.
TABLE 1______________________________________ Average .sup.14 Carbon Content in Lens Sample (dpm)* Days/StorageSample 5 9______________________________________Untreated HEMA 33 44homopolymerEDA-treated HEMA 109 89homopolymerEDA-treated HEMA- 2000 2145pNO.sub.2 .0.MA copolymer______________________________________*dpm = disintegrations per minute
In contrast to the low 14 carbon content of an EDA-treated HEMA homopolymer (shown by the low dpm values thereof), a similarly treated copolymer product of this invention absorbs a significant quantity of EDA as evidenced by the much increased 14 carbon readings. Therefore, unlike a straight HEMA-type lens material, the resistance of a copolymer product of this invention to protein absorption cannot be enhanced by treatment with EDA as taught, e.g., in U.S. Pat. No. 4,097,657.
EXAMPLE 2-4
Following the procedure as outlined in Example 1, other HEMA-pNO 2 .0.MA copolymers were prepared and then equilibrated in physiological saline solution. The amounts of the reactants employed, including those ofExamples 1A and 1B, are given in the table below.
TABLE 2______________________________________Ex- Ethyleneam- HEMA Glycol pNO.sub.2 .0.MA Initiator Initiatorple (ml) (ml) (g) Type Amount______________________________________1A 15 15 0.3 6% Ammon. 0.2 ml Persulfate 12% Sodium 0.2 ml Metabisulfite1B 15 15 -- 12% Sodium " Metabisulfite2 15 0.1 12% Sodium " Metabisulfate3 15 -- 0.03 12% Sodium " Metabisulfite4 15 -- 1.00 12% Sodium " Metabisulfite______________________________________
EXAMPLE 5
To illustrate that a HEMA-pNO 2 .0.MA hydrophilic copolymer of this invention is resistant to proteinaceous and other opacifying and contaminating materials without further structural modification, specimen discs of the copolymer products of Examples 1-4 were placed in separate vials each containing 2.5 mls of a simulated tear solution containing 3 H-lysozyme. This solution contained the following ingredients for each liter of aqueous solution:
0.9% NaCl
0.5988% lysozyme
0.0012% 3 H-lysozyme
0.06% albumin
0.04% urea
0.04% gamma-globulin
0.04% beta-globulin
0.004% glucose
The vials were maintained in a 37° C. shaker water bath for 24 hours. At the end of this time period, the specimen discs were removed from the sample vials and successively cleaned in commercial lens cleaningsolution and disinfected by boiling in 0.9% saline for approximately 20 minutes. Some of the disinfected samples were placed in scintillation fluid and counted for 3 H uptake which corresponds to bound protein. The remaining disinfected samples were placed in fresh 2.5 ml samples of the 3 H-tear solution and the aforedescribed storage procedure at 37° C. for 24 hours was repeated, followed by cleaning and disinfection of the samples and counting some for 3 H absorption/adsorption. This procedure were carried out for 115 days, with the results obtained as follows.
TABLE 3______________________________________dpm's* RetainedDays/StorageSample 25 40 55 70 85 100 115______________________________________1B 1384 1577 1949 2827 2718 3814 39241A 1061 961 1319 1402 1364 1957 12872 1619 1461 1890 1970 1811 2442 --3 1443 1623 2031 2726 2704 3474 37374 797 920 1497 1342 1067 1818 1090______________________________________*As previously described
These results indicate that the HEMA-pNO 2 .0.MA copolymer products of this invention are much more resistant to the absorption/adsorption of protein therein, by comparison to the HEMA homopolymer tested. The concentration of pNO 2 .0.MA in those copolymers showing more significant resistance to protein absorption (Samples 1A, 2 and 4) varies from about 0.6% to about 6% by weight of the total monomer mixture.
The aforesaid enhanced resistance to protein absorption/adsorption exhibited by a copolymer product of this invention by comparison to HEMA homopolymer is graphically illustrated in accompanying FIG. 1. The amount of protein diffused in or adhered to the copolymer lens (as evidenced by the number of dpms counted for such samples with continued storage in the simulated tear solution) is found to reach a maximum in about 40 days storage time and then to remain essentially at this level throughout the balance of the storage test. In contrast, the protein absorption/adsorption by the HEMA homopolymer (Sample 1B) keeps increasingwith continued storage in the 3 H-tear solution. By the end of the test, it can be seen that the resistance to protein diffusion of an optimal copolymer product of this invention (Sample 4) is approximately four times greater than that of a the HEMA homopolymer.
EXAMPLE 6
This example illustrates that copolymer products of this invention can easily be machined into lens shapes which are subsequently converted to soft contact lenses by hydration.
Aliquots of a mixture containing 60 ml HEMA (64.38 g) and 0.8 g of pNO 2 .0.MA were placed in polypropylene beakers which, in turn, were placed in glass, rubber stoppered bottles in a nitrogen atmosphere. These were placed in the gammator for 200 minutes, thus supplying 1.73×10 5 rads. There was obtained a HEMA copolymer containing 1.24% pNO 2 .0.MA by weight (Sample 6A).
Another copolymer was prepared as described above, employing 1.2 g pNO 2 .0.MA for each 60 ml of HEMA. The reaction mixture aliquots, in a nitrogen atmosphere, were maintained in the gammator for 400 minutes, thus providing 3.46×10 5 rads thereto. The finished copolymer contained 1.86% of pNO 2 .0.MA by weight (Sample 6B).
Further copolymers were prepared employing, in each instance, 60 ml HEMA, and 0.12 g benzoyl peroxide as the free radical initiator. In one of thesemixtures (Sample 6C), 0.8 g of pNO 2 .0.MA was incorporated; and in thesecond (Sample 6D), 1.2 g of pNO 2 .0.MA was used. Sample 6E employed only HEMA and initiator. All of these copolymers were prepared in aliquots, in a vacuum oven, under a nitrogen atmosphere at 65° C. for 20 hours. A sample of HEMA only (Sample 6F) was subjected to gamma radiation for 200 minutes, supplying approximately 1.73×10 5 rads.
Prior to hydration, the copolymer shapes were cut into contact lenses by Platt Contact Lens Service, Inc., Mansfield, Ohio, with the following results:
TABLE 4______________________________________ % pNO.sub.2 .0.MA, Type ofSample by Wt. Initiator Machineability______________________________________6A 1.24 Radiation Cut well, optics good6B 1.86 Radiation Cut well, optics fair-good6C 1.24 Benzoyl Poor, material Peroxide too soft6D 1.86 Benzoyl Cut smoothly, Peroxide although quite soft6E -- Benzoyl Material too Peroxide soft to cut6F -- Radiation Cut well, optics poor______________________________________
EXAMPLE 7
Polymerization reaction mixtures as follows were placed in a nitrogen-purged oven at 65° C. for approximately 36 hours.
TABLE 5______________________________________Sam- pNO.sub.2 .0.MA Solventple HEMA g. ml Initiator______________________________________A 16.1 0.3 Ethylene 0.2 ml 6% ammonium Glycol 15 persulfate 0.2 ml 12% sodium metabisulfiteB 16.1 -- Ethylene 0.3 g benzoyl peroxide Glycol 15C 32.2 0.6 -- 0.4 ml 6% ammonium persulfate 0.4 ml 12% sodium metabisulfiteD 32.2 0.6 -- 0.6 g benzoyl peroxide______________________________________
The above reaction mixtures, A, B and D successfully polymerized while mixture C did not. Samples of each copolymer prepared were leached with water for two weeks after preparation, while other samples thereof were stored in air for the same time period.
The infrared spectra of all of the samples, both leached and unleached, were obtained. A nitrophenyl methacrylate band was observed at approximately 1350 wavelengths in all of the spectra, indicating that no major changes in composition of the copolymer materials were brought aboutthrough leaching.
Water of Hydration
The water content of hydrated HEMA-pNO 2 .0.MA copolymer lenses was determined by first taring a weighing dish, then weighing the dish and thelens together, and calculating the weight of the copolymer lens material through difference. The hydrated lens samples were placed in an oven maintained at 75° C. for approximately 64 hours. The dried samples were weighed again and the differences in this weight and that of the dishalone was the weight of the unhydrated samples. The percentage of absorbed water was obtained by determining the amount of which was the difference between the hydrated and unhydrated sample.
The percentage of absorbed water was determined by obtaining the weight of the absorbed water (difference between weights of the hydrated and unhydrated samples) and dividing this value by the weight of the hydrated sample. Using this procedure, copolymer samples, A and B above, were foundto have about 38.5% of absorbed water; those of Sample D absorbed about 35.7% water by weight.
Contact Angle Measurements
The contact angles of stationary water drops (approximately 5 μl) on lens samples of the above-described copolymer formulations were measured on a Rame-Hart goniometer. Films of the copolymers were thoroughly washed,rinsed and cut into samples that would lie flat. These were then equlibrated with distilled water prior to measurement. Each sample, in turn, was placed on a microscope slide and anchored, carefully wiped free of surface water, and then placed in the goniometer for application of thewater droplet and measurement. A HEMA homopolymer was also tested as a control. The following results were obtained:
______________________________________ Average WaterSample Contact Angle - °______________________________________A 61.5B 61.0D 61.5alpha.sup.1 59.5Control 58.5______________________________________ .sup.1 Copolymer obtained by polymerizing a mixture containing 21.5 g of HEMA and 0.27 g of pNO.sub.2 .0.MA in a gammator for 200 minutes.
Copolymer products of this invention prepared using free radical initiationappear to be slightly less water-wettable than either the HEMA homopolymer control or the copolymer prepared through gamma radiation, as evidenced bythe foregoing water contact angle measurements obtained therefor.
EXAMPLE 8
For the oxygen transmissibility test, copolymer Samples A and D, and homopolymer Sample B of Example 7 above were employed. Also, a copolymer was used which had been prepared from a polymerization mixture containing 20 ml (approximately 21.5 g) HEMA and approximately 0.27 g pNO 2 .0.MA(1.26% pNO 2 .0.MA by weight). Aliquots of the prepared reaction mixture were then placed in polypropylene test tubes and placed in the gammator for 200 minutes (1.73×10 5 rads generated). The resulting copolymer samples (Sample E) were equilibrated as previously described. Finally, a HEMA homopolymer (Sample F) was prepared by irradiating 60 ml HEMA for 200 minutes (1.73×10 5 rads).
Oxygen Transmissibility
The oxygen permeability apparatus consisted of a barometer, a thermistor with tele-thermometer, a Clark-type polarographic oxygen electrode, an oxygen monitor, a chart recorder, a magnetic stirrer, and a two-chambered plastic cell fastened together with screws. The copolymer film sample to be tested was clamped between the cell halves, with an oxygenated saline solution in the one chamber and an oxygen-depleted saline solution, electrode and stirring bar in the other chamber. The increasing oxygen concentration in the electrode chamber was monitored as a function of timeand plotted by the chart recorder. The oxygen flux, J, was calculated from ##EQU1##where ##EQU2## is the % saturation change of O 2 per hour, AP is atmospheric pressure (mm Hg),
V is the electrode chamber volume (cc),
A is the area of the sample being measured (cm 2 ), and
S o is the solubility (in cc O 2 (STP)/100 cc solution) of oxygen at that chamber temperature (T°C.), atmospheric pressure (760 mm Hg), and [Cl - ] (which is usually 5140 ppm Cl - ).
The `dissolved` oxygen permeability, P d , is found from the formula ##EQU3##where L is the sample thickness (cm)
ΔpO 2 =the oxygen partial pressure difference between the upper and lower chambers at the point on the chart where ##EQU4## is analyzed.
In the test, the magnetic stirrer was spun at a speed beyond which further increases did not influence electrode response. Gas bubbles were carefullyexcluded from the electrode chamber, and the seal around the sample was necessarily air-tight. O 2 consumption by the electrode was minimized by measuring percent oxygen saturation periodically rather than continuously. Using this procedure, the following oxygen permeability values were obtained:
______________________________________ O.sub.2 Transmissibility*Sample Type Initiator P.sub.d______________________________________A Copolymer (NH.sub.4).sub.2 S.sub.2 O.sub.8 2.93 × 10.sup.-4 Na.sub.2 S.sub.2 O.sub.5B Homopolymer (NH.sub.4).sub.2 S.sub.2 O.sub.8 2.65 × 10.sup.-4 Na.sub.2 S.sub.2 O.sub.5D Copolymer Benzoyl 2.17 × 10.sup.-4 PeroxideE Copolymer IRRN 2.67 × 10.sup.-4F Homopolymer IRRN 2.91 × 10.sup.-4______________________________________*P.sub.d = μl O.sub.2 (STP) cm/cm.sup.2 Hr MM Hg
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Novel hydrophilic copolymers are prepared containing a major portion of polymerized units of an hydroxyalkyl acrylate or methacrylate monomer and a minor portion of a nitro-substituted aryl acrylate or methacrylate monomer, and optionally with a minor amount of an alkylene glycol diacrylate or methacrylate as a cross-linking agent. These copolymers are made by a free radical polymerization mechanism or by gamma radiation of the reaction mixture. These copolymers are particularly useful as soft contact lens polymers, being extremely resistant to clouding and/or discoloration in use.
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TECHNICAL FIELD
[0001] The present invention relates to a biomolecular detection method for detecting the methylated state of cytosine at a specific position in a nucleic acid.
BACKGROUND ART
[0002] It is becoming evident that methylation of the genome is an example of epigenetics observed in a wide range of biological species from Escherichia coli to plants to vertebrates, and this is associated with various living phenomena. Particularly in mammals, the methylation is also becoming an important area of study in view of ontogenesis, cell differentiation, canceration, and the like, and methylation of CpG islands in the promoter region of a gene is known to inactivate tumor-suppressor genes.
[0003] The methylation of a genome specifically arises from the methylation of cytosine contained in nucleic acid. The bisulfite method is currently most widely used as a method for detecting the methylated state of the cytosine contained in nucleic acid is a method utilizing the fact that bisulfite treatment of nucleic acid as a specimen does not convert methylcytosine and converts only cytosine to uracil (Patent Literatures 1 and 2). When after bisulfite treatment, the resultant is subjected to PCR and sequenced, uracil is detected as thymine and methylcytosine is detected as cytosine. The presence or position of methylation can be determined from the difference between cytosine and thymine (uracil) produced before and after treatment. However, the disadvantages of the bisulfite method are that its sequencing operation is cumbersome, the method has a long reaction time (typically a dozen hours or so) for complete modification, and the treatment often produces a depurination reaction and often causes fragmentation of the sample; thus, the method requires improvement.
[0004] As a method other than this method, a quantitation method for methylcytosine using an anti-methylcytosine antibody has been reported (Patent Literature 3). However, the quantitation method for methylcytosine using the antibody can measure the total amount of methylcytosine contained in a nucleic acid of interest, but does not enable it to be determined at which position in the base sequence cytosine is methylated. For gene expression, it is crucial to know which cytosines are methylated, not just the frequency of cytosine methylation.
[0005] The present inventors have recently reported a method for selectively quantitating the methylation of cytosine at a specific position in a base sequence using an anti-methylcytosine antibody together with experimental results using synthetic oligomers (Patent Literature 4). This method involves placing the cytosine to be detected at a specific position in a nucleic acid in a DNA bulge formed by mismatching when the nucleic acid hybridizes with a complementary strand and measuring the amount of an anti-cytosine antibody or an anti-methylcytosine antibody binding to the nucleic acid; this enables it to be determined whether or not the cytosine to be detected is methylated.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: Japanese Patent Application Laid-Open No. 2006-238701
Patent Literature 2: Japanese Patent Application Laid-Open No. 2004-008217
Patent Literature 3: Japanese Patent No. 3854943
Patent Literature 4: Japanese Patent Application Laid-Open No. 2012-230019
SUMMARY OF INVENTION
Technical Problem
[0010] The method for determining whether or not the particular cytosine to be detected in a nucleic acid is methylated by placing the cytosine to be detected in a DNA bulge formed when the nucleic acid hybridizes to a complementary strand and measuring the amount of an antibody binding to the nucleic acid can advantageously detect the methylation of the cytosine in experiments using synthesized oligomers, but it is difficult for a method like this to detect the methylation of a particular cytosine when the genomic DNA to actually be analyzed is used. This is because the presence of a large amount of DNA other than the base sequence of interest makes it difficult to selectively detect only methylated cytosine at a specific site since methylated cytosine can be present in areas other than that hybridizing to a complementary strand and the antibody also binds to the methylated cytosine.
[0011] An object of the present invention is to eliminate the drawback of the invention and to provide a method for selectively detecting the methylation of particular cytosines in genomic DNA using a methylcytosine detection method using an anti-methylcytosine antibody to improve quantitativity and reliability.
Solution to Problem
[0012] The present inventors have succeeded in selectively detecting methylation of particular cytosines in genomic DNA, as explained below.
[0013] A restriction enzyme was first added to the genomic DNA specimen to be measured, to fragment the DNA. The nucleic acid sequence of each of the formed DNA fragments is dependent on the restriction enzyme used. This enables the excision, from the genome, of the nucleic acid to be measured consisting of a particular sequence containing the cytosine to be detected at a specific position as its fragment.
[0014] An ultrasonic wave or the like has conventionally been used to fragment DNA; however, such a method produces a variable number of fragments and thus is not suitable for the methylcytosine detection method of the present invention using a nucleic acid having complementarity to the nucleic acid to be measured as a detection reagent, as will be described below, although this does not present a particular problem in a subsequent PCR method or the like for amplifying the particular sequence.
[0015] The nucleic acid to be measured has then been mixed with a single-stranded nucleic acid having a sequence complementary to the nucleic acid to be measured except for a base with which the cytosine to be detected is to form a base pair for hybridization to form a double-stranded DNA.
[0016] The base sequence of the single-stranded nucleic acid is a sequence not forming a base pair with the cytosine to be detected while having complementarity and length sufficient to form a double strand with the nucleic acid to be measured. The base sequence is designed considering the end sequence of the nucleic acid to be measured formed by cleavage with the restriction enzyme so that an unpaired base is not left at the end of the formed double-stranded DNA.
[0017] The formed double-stranded DNA is subsequently bound to a solid phase via a solid phase-binding site provided in the single-stranded nucleic acid for recovery on the solid phase. The remaining DNA fragments are removed by washing.
[0018] Thereafter, the double-stranded DNA bound on the solid phase is exposed to an antibody.
[0019] Even when the formation of a double strand with the complementary nucleic acid has resulted in the presence of methylcytosine at a position that is not determined in the nucleic acid to be analyzed, the methylcytosine forms a base pair with guanine so as to greatly decrease the probability of being recognized by the antibody. In contrast, methylcytosine at the position to be determined, not forming the base pair is recognized by a highly efficient antigen-antibody reaction. This has enabled the selective detection of the methylated states of particular cytosines in genomic DNA.
[0020] Further details of the steps of the present invention follow.
[0021] (1) A nucleic acid to be measured is cleaved and fragmented with a restriction enzyme.
[0022] Although various restriction enzymes recognizing a particular base sequence and cleaving a nucleic acid are known, a restriction enzyme can be selected, which is capable of cleaving the base sequence to be measured in a manner flanking the sequence. One restriction enzyme may be used, or a combination of two restriction enzymes may be used.
[0023] (2) Hybridization is performed by adding a single-stranded nucleic acid having a base sequence designed so that the cytosine to be detected does not form a base pair while forming a double strand with the base sequence of interest.
[0024] Genomic DNA typically forms a double strand in vivo. Thus, the fragmented nucleic acid is preferably once heated to or above its melting temperature after adding the single-stranded nucleic acid to make single strands and again slowly cooled for hybridization with the single-stranded nucleic acid. In addition, it is preferable to add the single-stranded nucleic acid in excess based on the nucleic acid to be measured to highly efficiently hybridize with the single-stranded nucleic acid. Further, the base sequence of the single-stranded nucleic acid is designed considering a combination with the restriction enzyme so that an unpaired base does not remain at the end of the formed double-stranded DNA. It is ensured that the single-stranded nucleic acid also has a solid phase-binding site for subsequent recovery on the solid phase.
[0025] (3) The double-stranded nucleic acid having the solid phase-binding site hybridized to the object to be measured is recovered utilizing the solid phase-binding site.
[0026] In recovery, it is a good idea to provide a solid phase suited for a subsequent detection method. For example, recovery on a gold or silver thin film is desirable for a surface plasmon resonance method. Recovery may also be performed in wells of a microtiter plate, followed by detection using an enzyme immunoassay method. Recovery may be performed not only on a flat material such as a substrate, but also on polystyrene or magnetic particles.
[0027] (4) An antibody is introduced, and the amount of the bound antibody is measured to measure the rate of cytosine methylation.
[0028] For example, when an anti-methylcytosine antibody is added, the methylation of the cytosine to be detected will result in the binding of the anti-methylcytosine antibody to the double-stranded nucleic acid. The surface plasmon resonance method can detect the antibody from a change in a refractive index without labeling the antibody with an enzyme or a fluorophore. Common techniques having been used for conventional immunoassay methods can be widely used. As is obvious to one skilled in the art, there is, for example, a method which involves labeling the antibody with an enzyme, a fluorophore, a radioisotope, or a metallic nanoparticle. Detection by introducing a secondary antibody labeled with any of the labels is also possible.
[0029] Thus, the invention of the present application has the following aspects.
[0030] 1. A method for detecting the methylated state of cytosine at a specific position in a nucleic acid, comprising the steps of:
[0031] fragmenting the nucleic acid using a restriction enzyme;
[0032] forming a double-stranded nucleic acid between the fragmented nucleic acid and a single-stranded nucleic acid having a base sequence capable of hybridizing with the fragmented nucleic acid but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid and a solid phase-binding site;
[0033] binding the double-stranded nucleic acid on a solid phase using the solid phase-binding site; and
[0034] measuring the amount of an antibody binding to the double-stranded nucleic acid on the solid phase.
[0035] 2. The method according to 1, wherein the antibody is an anti-methylcytosine antibody.
[0036] 3. The method according to 1 or 2, wherein the solid phase-binding site is biotin and the solid phase is avidin.
[0037] 4. The method according to any one of 1 to 3, wherein the amount of the antibody binding to the double-stranded nucleic acid is measured by detecting the binding of the antibody by a surface plasmon resonance method.
[0038] 5. The method according to 1 to 3, wherein the amount of the antibody binding to the double-stranded nucleic acid is measured by using a horseradish peroxidase-labeled antibody as the antibody, binding the antibody before adding a substrate for the horseradish peroxidase, and detecting a change in absorbance due to a reaction product of the horseradish peroxidase.
[0039] 6. The method according to 1 to 5, wherein the base sequence capable of hybridizing to the fragmented nucleic acid but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid used is a single-stranded nucleic acid having a base sequence in which the point to form a base pair with the cytosine to be detected is an abasic site.
[0040] 7. The method according to 1 to 5, wherein the base sequence capable of hybridizing to the fragmented nucleic acid but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid used is a single-stranded nucleic acid having a base sequence in which the cytosine to be detected is to be placed in a bulge structure in forming the double-stranded nucleic acid.
[0041] 8. The method according to 1 to 5, wherein the base sequence capable of hybridizing to the fragmented nucleic acid but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid used is a single-stranded nucleic acid having a base sequence in which the point to form a base pair with the cytosine to be detected is adenine, cytosine, or thymine.
[0042] 9. The method according to any one of 1 to 8, wherein the single-stranded nucleic acid having a base sequence capable of hybridizing to the fragmented nucleic acid but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid and a solid phase-binding site is added in an amount of 1 to 100 times, both inclusive, the concentration of the fragmented nucleic acid to be measured to form the double strand.
[0043] 10. The method according to 1 to 9, wherein the base sequence of the single-stranded nucleic acid having a base sequence capable of hybridizing with the fragmented nucleic acid but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid and a solid phase-binding site is such a base sequence that a blunt end is formed in a double-stranded nucleic acid in forming the double strand with the nucleic acid to be measured fragmented by the restriction enzyme.
[0044] 11. A kit for detecting methylcytosine in a nucleic acid sequence, comprising a combination of a restriction enzyme, a single-stranded nucleic acid having a base sequence capable of hybridizing with the fragmented nucleic acid to be measured but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid and biotin, an anti-methylcytosine antibody, and a solid-phased avidin.
Advantageous Effects of Invention
[0045] In the conventional method for determining whether or not the particular cytosine to be detected in a nucleic acid is methylated by placing the cytosine to be detected in a DNA bulge formed when the nucleic acid hybridizes to a complementary strand and measuring the amount of an antibody binding to the nucleic acid, it is difficult to selectively detect the methylation of the particular cytosine in DNA specimens, such as genomic DNA, to be actually analyzed because any methylcytosine mismatched with the complementary strand is recognized by an anti-methylcytosine antibody; the method has had poor industrial utility. The present invention has enabled the selective detection of the presence of the methylation of particular cytosine in the base sequence portion to be measured from a very long genome because it results in the base pair formation of any cytosine other than the cytosine to be detected with guanine, and thereby in no detection of methylcytosine to not be measured. This achieves greatly improved selectivity of the detection of the methylation of cytosine compared to that for the conventional methylcytosine detection technique using an anti-methylcytosine antibody.
BRIEF DESCRIPTION OF DRAWINGS
[0046] FIG. 1 is a schematic diagram showing the procedure of fragmenting a nucleic acid containing the area to be measured with a restriction enzyme, recovering the nucleic acid fragment of the area to be measured by hybridization to a biotinylated single-stranded nucleic acid, and detecting the particular cytosine to be detected with an anti-methylcytosine antibody, using the present invention.
[0047] FIG. 2 is a schematic diagram showing the procedure of preparing a sensor when the measurement of antigen-antibody reaction in the present invention is carried out using a surface plasmon resonance method.
[0048] FIG. 3 is a schematic diagram showing the procedure of measurement when the measurement of antigen-antibody reaction in the present invention is carried out using a surface plasmon resonance method.
[0049] FIG. 4 is a graph comparing the results of measuring the surface plasmon resonance angle for methylated DNA and unmethylated DNA in Example 1.
[0050] FIG. 5 is a graph comparing the results of measuring the surface plasmon resonance angle for methylcytosine using various complementary nucleic acids in Example 2.
[0051] FIG. 6 is a graph showing the results of measuring the methylation rate of DNA by an enzyme immunoassay method in Example 3.
[0052] FIG. 7 is a graph showing the results of measuring a response when the amount of a complementary nucleic acid relative to the nucleic acid to be measured is changed by an enzyme immunoassay method in Example 4.
DESCRIPTION OF EMBODIMENTS
[0053] The measurement procedure for the methylated state of cytosine at a specific position in a nucleic acid sequence according to the present invention is shown in FIG. 1 .
[0054] According to the present invention, in selectively measuring only a nucleic acid having the base sequence to be measured (step 1 in FIG. 1 ) in a genome, the genomic DNA is first cleaved at any position with a restriction enzyme. The restriction enzyme used can be properly selected to suit the base sequence of the area to be measured. For example, AluI enzyme is known to recognize only 5′-AGCT-3′ to cleave a nucleic acid between adjacent G and C bases. A restriction enzyme is used to prepare the fragment of the base sequence of the area to be measured (step 2 in FIG. 1 ). The base sequence of the area to be measured is determined by the selection of a restriction enzyme.
[0055] A biotinylated single-stranded nucleic acid is then added (step 3 in FIG. 1 ). Biotin is used as a solid phase-binding site. The base sequence of the biotinylated nucleic acid serves as a base sequence incapable of resulting in the formation of a base pair with the cytosine to be detected while having complementarity enabling the formation of a double strand with the nucleic acid of the area to be measured fragmented by the restriction enzyme. Examples of such a base sequence include a base sequence obtained by removing only guanine capable of forming a base pair with the cytosine to be detected from a base sequence as a completely complementary strand for the nucleic acid to be measured. In this case, the cytosine to be detected will be placed within a DNA bulge in the formed double-stranded DNA. The same is also possible by replacing guanine capable of forming a base pair with the cytosine to be detected in a completely complementary strand with cytosine, adenine, or thymine. In this case, the cytosine to be detected is in the state of being incapable of forming a base pair in the formed double-stranded DNA. Only the base moiety of guanine capable of forming a base pair with the cytosine to be detected in a completely complementary strand can also be removed to leave the deoxyribose to make an abasic site. Also in this case, the cytosine to be detected is in the state of being incapable of forming a base pair in the formed double-stranded DNA.
[0056] In addition, the base sequence of the biotinylated nucleic acid is preferably made in a state referred to as having a blunt end, in which an unpaired base is not present, by keeping the ends of both strands of a double-stranded nucleic acid aligned in forming a double strand with the nucleic acid to be measured. The blunt end can be obtained by matching the cleavage point for a restriction enzyme to the base sequence of the biotinylated single-stranded nucleic acid. The reason the blunt end is preferable is that the presence of methylcytosine as an outstanding unpaired base in the ends of both strands of the double-stranded nucleic acid results in the binding of the methylcytosine to the antibody and thus a methylation rate higher than an actual value. Even if an unpaired base is present in the ends of both strands of the double-stranded nucleic acid, the unpaired base being not methylcytosine is not directly a problem since it is not recognized by an anti-methylcytosine antibody. However, as described above, it is relatively easy to form a blunt end by the combination of a restriction enzyme and the base sequence of the biotinylated single-stranded nucleic acid; thus, an unpaired base is preferably absent in the ends of both strands of the double-stranded DNA.
[0057] Further, the biotinylated nucleic acid preferably has the same or higher concentration than that of the fragmented nucleic acid to be measured. This is for the purpose of decreasing the probability that the nucleic acid to be measured will hybridize again to the nucleic acid having originally formed a double strand. However, addition in large excess is not preferable because the rate of subsequent recovery on the solid phase is decreased. Thus, the amount of the biotinylated nucleic acid to be added is preferably on the order of 1 to 100 times that of the fragmented nucleic acid to be measured.
[0058] The nucleic acid to be measured is hybridized to the biotinylated single-stranded nucleic acid (step 4 in FIG. 1 ). The hybridization method involves once heating to the melting temperature (called Tm value) of the fragmented nucleic acid to be measured or higher, followed by slow cooling. In slow cooling, maintaining at around the Tm value for about 30 minutes improves the specificity of hybridization.
[0059] Thereafter, the nucleic acid to be measured hybridized to the biotinylated single-stranded nucleic acid is recovered using avidin-biotin binding (step 5 in FIG. 1 ). Biotin is known to firmly bind to avidin (and streptavidin). It is convenient for avidin to be immobilized on the solid phase surface in advance to suit a subsequent measurement method. For example, for the surface plasmon resonance method, avidin is immobilized on the gold thin film surface. For the enzyme immunoassay method, it is immobilized in the wells of a polystyrene or polyvinyl chloride microtiter plate. A method using avidin-immobilized magnetic beads is also widely known. As a method for immobilizing avidin, a heretofore known method can be widely used.
[0060] The nucleic acid mixture containing the biotinylated nucleic acid hybridized with the nucleic acid to be measured is introduced onto an avidin-immobilized substrate to selectively immobilize only the nucleic acid to be measured on the substrate by avidin-biotin binding. The substrate is then washed to remove the nucleic acid to not be measured which has not been hybridized with the biotinylated nucleic acid.
[0061] Thereafter, an anti-methylcytosine antibody is bound to the nucleic acid to be measured which is hybridized to the biotinylated nucleic acid and immobilized on the substrate (step 6 in FIG. 1 ). For the surface plasmon resonance method, a change in a refractive index due to the binding of antibody is observed; thus, the anti-methylcytosine antibody need not be labeled and can be detected on its own. In the enzyme immunoassay method, detection is carried out by labeling the anti-methylcytosine antibody with an enzyme, such as horseradish peroxidase, in advance, or using a secondary antibody method.
EXAMPLES
[0062] The present invention will now be more specifically described below based on Examples. However, the present invention is not intended to be limited to the Examples.
Example 1
[0063] This Example shows the experimental results of confirming that the present invention can measure methylcytosine in DNA by a surface plasmon resonance method.
[0064] The sensor chip used for surface plasmon resonance was prepared as follows by laminating a polydimethylsiloxane substrate on which a flow path was formed on a glass substrate having a gold thin film.
[0065] In preparing the polydimethylsiloxane substrate, an oligomer of polydimethylsiloxane (PDMS) (Corning Incorporated) and a hardener were mixed in a substrate providing a template for the flow path (3 mm in width, 10 mm in length, and 20 μm in depth), which was then allowed to stand at 60° C. for 2 hours for hardening. The resultant was then taken off the template to provide a PDMS substrate having the flow path.
[0066] The glass substrate having a gold thin film was prepared as follows. A sticker perforated with 2 holes 3 mm in diameter was affixed to a BK7 glass substrate 18 mm square. Thereafter, using a magnetron sputtering system (Seed Lab., Corporation), titanium was deposited at 3 nm on the glass substrate and a gold thin film was further deposited at 50 nm thereon. The resultant was taken out of the magnetron sputtering system, followed by peeling off the sticker to prepare a glass substrate having 2 gold thin films 3 mm in diameter (step 1 in FIG. 2 ).
[0067] The immobilization of avidin on the gold thin film surface was performed as follows. Decanethiol carboxylate was dissolved in ethanol to prepare a 1 mM solution. The glass substrate having a gold thin film was immersed in the solution overnight to modify the gold surface with decanethiol carboxylate by gold-thiol binding (step 2 in FIG. 2 ). Then, 5 μL of MES buffer containing 5 mM N-hydroxysulfosuccinimide and 40 mM N,N′-diisopropylcarbodiimide (pH 6.0) were added dropwise to only one of the gold thin films, which was then reacted at room temperature for 30 minutes to activate the carboxyl group of decanethiol carboxylate. The gold thin film was subsequently washed with pure water and reacted with 0.1 mg/mL streptavidin (diluted with phosphate buffer (pH 7.4)) at room temperature for 2 hours (step 3 in FIG. 2 ). After washing with pure water, the resultant was reacted with 1 M ethanolamine (diluted with phosphate buffered saline (pH 7.4)) at room temperature for 15 minutes for inactivation and was then washed with pure water. Finally, the polydimethylsiloxane substrate on which a flow path was formed was laminated on the glass substrate having a gold thin film to make a sensor.
[0068] The fragmented methylated genomic DNA specimen was prepared as follows. λDNA (Takara Bio Inc., code No. 3010, about 48,000 bp) was used. 40 μL of λDNA (stock solution: 0.34 μg/μL) was taken, and 10 μL of AluI (Takara Bio Inc.) as a restriction enzyme and 50 μL of 10×buffer provided with the restriction enzyme were placed therein. The mixture was then reacted at 37° C. for 4 hours to fragment λDNA. Thereafter, 2 μL (8 units) of an enzyme methylating cytosine located at the CpG regions (M. SssI, New England Biolabs Inc.) and 10 μL of S-adenosylmethionine (stock solution: 32 mM) were placed therein, which was then reacted overnight. The λDNA treated with the enzyme was handled as DNA methylated in the CpG regions. The sequence of the DNA is 5′-CTTTCCCGGAATTACGCCCAGATGAG-3′ (C at the 15th base from the 5′-end is methylcytosine) (SEQ ID NO: 1). Using combined bisulfite restriction analysis (COBRA method) as a conventional method, it was confirmed that 99% or more of the CpG regions to be measured were methylated.
[0069] Using Unmethylated λDNA (Promega KK., catalog No. D1521) as λDNA not methylated in CpG, a fragmented specimen was similarly prepared. This λDNA lacks dam and dcm methylase activities and is on the market as one containing no methylcytosine.
[0070] The present inventors have also confirmed by the COBRA method that 1% or less of the CpG regions to be measured were methylated in the fragmented DNA prepared using this λDNA.
[0071] Measurement was carried out as follows. A surface plasmon resonance sensor (NTT Advance Technology Corporation) was equipped with the sensor chip prepared above through matching oil. A specimen was then introduced into the sensor using a syringe pump (CMA Corporation). Phosphate buffer (containing 0.1% bovine serum albumin and 0.05% Tween 20) was used for this measurement. First, the fragmented λDNA to be measured and a biotinylated nucleic acid were mixed to a final concentration of 935 pM. The base sequence of the biotinylated nucleic acid used in this Example was 5′-CTCATCTGGGCTAATTCCGGGAA AG-3′ (SEQ ID NO: 2), was a sequence completely complementary to the sequence of the DNA to be measured except for the absence of a base corresponding to C at the 15th base from the 5′-end of the sequence of the DNA to be measured, and had biotin at the 5′-end. The mixture was heated at 95° C. for 5 minutes and then slowly cooled to room temperature (step 1 in FIG. 3 ).
[0072] Ten-fold dilution series were prepared using phosphate buffer, and the diluted specimens were each introduced at a flow rate of 2 μL/minute for 30 minutes to capture the biotinylated nucleic acid with streptavidin in the sensor (step 2 in FIG. 3 ). Streptavidin can be immobilized in only one sensor to capture the biotinylated nucleic acid only by the streptavidin-immobilized gold thin film surface.
[0073] Phosphate buffer (containing 0.1% bovine serum albumin and 0.05% Tween 20) was introduced as a running buffer into the sensor for 15 minutes for washing to stabilize the response of the sensor, followed by introducing 10 μg/mL of an anti-methylcytosine antibody (Aviva Systems Biology Corporation) to observe the amount of the antibody binding to the biotinylated nucleic acid captured in the sensor as a change in the surface plasmon resonance angle. Since streptavidin was immobilized in one of the sensors, the change in the surface plasmon resonance angle on the gold thin film surface on which streptavidin was not immobilized can be thought as the nonspecific adsorption amount of other than the nucleic acid to be measured. The surface on which streptavidin is not immobilized is not essential; however, the use of this surface enables easy estimation in measuring the nonspecific adsorption amount.
[0074] The measurement results are shown in FIG. 4 . For λDNA in which the CpG regions are methylated, the amount of change in the surface plasmon resonance angle was shown to increase with increasing specimen concentration. However, the change in the surface plasmon resonance angle was small for the unmethylated DNA. These are because the introduction of the anti-methylcytosine antibody resulted in the binding of the anti-methylcytosine antibody to methylated cytosine in the nucleic acid to be measured hybridized to the biotinylated nucleic acid, increasing the refractive index of the gold thin film surface. Thus, the method of the present invention can measure whether or not cytosine in genomic DNA has been methylated.
Example 2
[0075] This Example shows that it is suitable for the biotinylated nucleic acid used in the present invention to be made in a base sequence not forming a base pair with the cytosine to be detected.
[0076] DNA was prepared as follows. The nucleic acid to be measured used was 5′-TTG CGC GGC GTC CGT CCT GTT GAC TTC-3 (C at the 13th base from the 5′-end is methylcytosine) (SEQ ID NO: 3). The nucleic acid to be measured was hybridized to each of the following 6 biotinylated nucleic acids by the same procedure as in Example 1.
[0077] 5′-GAA GTC AAC AGG AC — GAC GCC GCG CAA-3′ (SEQ ID NO: 4) is designed so that the cytosine to be detected is placed in the bulge.
[0078] 5′-GAA GTC AAC AGG ACA GAC GCC GCG CAA-3′ (SEQ ID NO: 5) has a mismatch in which the base to form a base pair with the cytosine to be detected is A.
[0079] 5′-GAA GTC AAC AGG ACT GAC GCC GCG CAA-3′ (SEQ ID NO: 6) has a mismatch in which the base to form a base pair with the cytosine to be detected is T.
[0080] 5′-GAA GTC AAC AGO ACC GAC GCC GCG CAA-3′ (SEQ ID NO: 7) has a mismatch in which the base to form a base pair with the cytosine to be detected is C.
[0081] 5′-GAA GTC AAC AGG ACd GAC GCC GCG CAA-3′ (SEQ ID NO: 8) has a mismatch in which the base to form a base pair with the cytosine to be detected is an abasic site (called an AP site).
[0082] 5′-GAA GTC AAC AGG ACG GAC GCC GCG CAA-3′ (SEQ ID NO: 9) is a completely complementary strand in which the base to form a base pair with the cytosine to be detected is G.
[0083] In this Example, the surface plasmon resonance measuring instrument used was a sensor chip in which Biacore T100 (GE Healthcare) and streptavidin are immobilized (Sensor chip SA, GE Healthcare).
[0084] First, 1 nM DNA forming a double strand was fed to the sensor chip at 10 μL/minute for 30 minutes for capture on the sensor surface. Then, various concentrations (0.25, 0.5, 1, 2.5, 5, 10, 25, and 50 nM) of an anti-methylcytosine antibody were fed at 10 μL/minute for 10 minutes. As a running buffer, HBS-EP buffer (pH 7.4, containing 10 mM HEPES, 0.15 M NaCl, 3 mM EDTA, and 0.05% v/v Surfactant P20) from GE Healthcare was used. Then, a buffer containing no antibody was fed at 10 μL/minute for 5 minutes. Thereafter, as a regeneration solution, 50 mM Gly-NaOH (pH 10.6) was fed at 60 μL/minute for 30 seconds. Under the conditions of this regeneration solution, it has been confirmed that the antigen-antibody reaction is dissociated while the double strand of DNA is maintained, enabling the antibody to be repeatedly fed.
[0085] The measurement results are shown in FIG. 5 . The largest response was obtained when methylcytosine was placed in the bulge. A large response was also obtained when the point to form a base pair with methylcytosine is an abasic site (called an AP site). In contrast to these cases, no binding of the anti-methylcytosine antibody was observed to the completely complementary double strand. It was shown that a slight response could also be obtained when the point to form a base pair with methylcytosine was adenine, cytosine, or thymine and these are also applicable for the present invention.
[0086] The results of this Example clearly show that it is necessary for the base sequence of the biotinylated nucleic acid used in the present invention to have a base sequence in which a base pair is not formed with the.
Example 3
[0087] This Example shows the experimental results of confirming that the method of the present invention can measure the rate of cytosine methylation in DNA by an enzyme immunoassay method.
[0088] The DNA to be measured used was fragmented ADNA. The DNA specimen, in which all CpG regions were methylated, was prepared by methylation with an enzyme as in Example 1. The DNA specimen, in which all CpG regions are not methylated, that was used was fragmented unmethylated λDNA (Promega KK., catalog No. D1521) as in Example 1. These specimens were mixed to prepare a DNA specimen sample having a methylation rate of 0, 25, 50, 75, or 100%. The resultant DNAs were each mixed with the same biotinylated nucleic acid as that in Example 1, heated at 95° C. for 5 minutes, and then slowly cooled to room temperature.
[0089] The enzyme immunoassay method was performed as follows. A streptavidin-coated plate (Sumitomo Bakelite Co., Ltd.) was provided, and 200 μL each of the DNA specimens were introduced into its wells. Washing was carried out with 300 μL of a buffer (containing phosphate buffered saline, pH 7.4, and 0.05% Tween 20) 3 times, followed by adding 50 μL of 1 μg/mL of a horseradish peroxidase-labeled anti-methylcytosine antibody to each well and conducting reaction at 37° for 30 minutes under seal. Washing was carried out with 300 μL of the buffer 4 times, followed by adding 50 μL of a tetramethylbenzidine solution (Bethyl Laboratories Inc.) and conducting reaction for 10 minutes under light-shielding. A 2N hydrochloric acid solution (50 μL) was added to stop the reaction, and absorbance at 450 nm was measured using a microplate reader (BioRad model 680).
[0090] The measurement results are shown in FIG. 6 . The absorbance was confirmed to increase with increasing methylation rate. From this, it was found that the present invention enabled the measurement of the rate of cytosine methylation in DNA by an enzyme immunoassay method.
Example 4
[0091] This Example shows that it is suitable for a biotinylated single-stranded nucleic acid to be added in an amount of 1 to 100 times, both inclusive, the concentration of the nucleic acid fragment to be measured in the method of the present invention.
[0092] The DNA to be measured used was 5′-CTTTCCCGGAATTACGCCCAGATGAG-3′ (C at the 15th base from the 5′-end is methylcytosine) (SEQ ID NO: 1). The object to be measured and DNA (5′-CTCATCTGGGCGTAATTCCGGGAAAG-3′) (SEQ ID NO: 10) as a completely complementary strand were mixed at the same concentration (1 nM), heated at 95° C. for 5 minutes, and then slowly cooled to room temperature to form a completely complementary double strand. A biotinylated nucleic acid (5′-(biotin)CTCATCTGGGCTAATTCCGGGAA AG-3′, the absence of a complementary base G corresponding to C at the 15th base from the 5′-end of the DNA to be measured (SEQ ID NO: 2)) was added to a final concentration of 0, 0.5, 1, 5, 10, 50, or 100 nM to the double-stranded DNA, which was then again heated at 95° C. for 5 minutes and then slowly cooled to room temperature to hybridize the biotinylated nucleic acid to the DNA to be measured having methylcytosine. Thereafter, measurement was carried out by the enzyme immunoassay method as in Example 3.
[0093] The measurement results are shown in FIG. 7 . A larger response was obtained by increasing the amount of the biotinylated nucleic acid relative to that of the nucleic acid to be measured. This is because of an increase in the proportion of the nucleic acid to be measured hybridized with the biotinylated nucleic acid. However, an amount in extreme excess decreases the response because it decreases the recovery rate of the biotinylated nucleic acid. Under the present conditions, the concentration of the same to on the order of 100 times that of the nucleic acid to be measured was shown to be satisfactory.
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To provide a method for selectively detecting the methylation of particular cytosines in genomic DNA using a methylcytosine detection method using an anti-methylcytosine antibody to improve quantitativity and reliability. A method for detecting the methylated state of cytosine at a specific position contained in a nucleic acid, includes fragmenting the nucleic acid using a restriction enzyme; forming a double-stranded nucleic acid between the fragmented nucleic acid and a single-stranded nucleic acid having a base sequence capable of hybridizing with the fragmented nucleic acid but incapable of resulting in the formation of a base pair with cytosine at a specific position in the fragmented nucleic acid and a solid phase-binding site; binding the double-stranded nucleic acid on a solid phase using the solid phase-binding site; and measuring the amount of an antibody binding to the double-stranded nucleic acid on the solid phase.
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FIELD OF THE INVENTION
[0001] The present invention relates to a device and a method for enhancing the solderability, and more particularly, to a device and a method for enhancing the solderability for a lead-free soldering component.
BACKGROUND OF THE INVENTION
[0002] With the improvement of living standard, more and more attention is paid for the negative effect caused by the manufacturing industry, and as a result of which, the legislation for the international environmental regulations as well as the specific practice procedures thereof are improved, where the use of hazardous substance is severely restricted thereby, so as to assure the sustained development in industry. Accordingly, the so-called “green industry” is well developed nowadays.
[0003] One principal purpose of the development of green industry is to fabricate and provide a green product, i.e. for achieving a lead-free and non-hazardous process in the electronics industry. Regarding the increasing requirements for the green industry, Restriction of Hazardous Substance (RoHS), purposed by the European Union (EU) in 2002, is the most focused one at present. Under the regulations of RoHS, it is required that from Jul. 1, 2006, the consumer electronics products to be imported into any member state of EU shall be completely lead-free. Accordingly, there are more and more international manufacturers trying to introduce the possible lead-free procedure into their existing manufacturing process for obtaining a lead-free product, so as to comply with the mentioned regulations.
[0004] Based on the mentioned, it becomes a critical issue to replace the existing lead-containing component with a lead-free one in the conventional electronics industry, which brings a series of challenges therefor.
[0005] In the conventional procedures of electronics manufacturing industry, the lead-tin alloy is typically applied for serving as the soldering component for bonding the die to a substrate or assembling a package. Under the mentioned requirements for the lead-free device, however, more efforts need to be done for the relevant techniques to obtain a further alloy that is available for replacing the conventional lead-tin alloy, so as to reduce the lead content of the soldering component and to retain the reliability in soldering and the preservability as well.
[0006] In addition to the composition of the soldering component, the improvement for solderability thereof is also regarded as a critical issue to be solved. Referring to the U.S. Pat. No. 5,086,966, a method for improving the wetting ability of a solder of lead-tin alloy and the relevant composition thereof are disclosed therein. The solder of lead-tin alloy is pretreated to deposit palladium thereon prior to soldering to a metallic substrate, which enhances the wetting of the substrate by the solder liquid during reflow, and thus a strong metallurgical bond is produced thereby.
[0007] Nevertheless, such method is developed specifically for the solder of lead-tin alloy, which apparently fails in the international tendency for lead-free demand, and thus needs to be further improved. Moreover, with the introduction of the lead-free procedure, it also needs to provide the lead-free component with a recognizable appearance for separating from the lead-containing ones in the procedure, so as to prevent the process confusion.
[0008] For overcoming the mentioned issues caused by the prior art, a method and a device for enhancing the solderability of a lead-free component are provided in the present invention. The provided method is compatible with the conventional soldering process and is capable of improving the wetting ability of the solder so as to enhance the solderability and the ability of anti-oxidation thereof. Besides, the present invention also provides a recognizable lead-free device so as to prevent the process confusion.
SUMMARY OF THE INVENTION
[0009] In accordance with a first aspect of the present invention, a lead -free solder is provided. The provided lead-free solder includes at least a first metal and a second metal located thereon, where the oxidation potential of the second metal is higher than the oxidation potential of the first metal.
[0010] Preferably, the first metal includes tin (Sn).
[0011] Preferably, the second metal is nickel (Ni), gold (Au), palladium (Pd), platinum (Pt) or silver (Ag).
[0012] In accordance with a second aspect of the present invention, a recognizable soldering component is provided. The provided recognizable soldering component includes at least a first metallic layer and a second metallic layer formed thereabove, wherein, the second metallic layer has a color rather than that of the first metallic layer.
[0013] Preferably, the recognizable soldering component is one selecting from a group consisting of a solder ball, a bump, a pin and a terminal electrode.
[0014] Preferably, the recognizable soldering component has a lead content less than 1000 ppm.
[0015] Preferably, the first metallic layer includes tin (Sn).
[0016] Preferably, the second metallic layer is made of an inert metal.
[0017] Preferably, the inert metal includes gold (Au).
[0018] In accordance with a third aspect of the present invention, a recognizable soldering component having a relatively high solderability for connecting a die to a substrate is provided. The provided recognizable soldering component includes at least a first metallic layer and a second metallic layer located thereabove, wherein the second metallic layer has a color rather from that of the first metallic layer.
[0019] Preferably, the oxidation potential of the second metallic layer is higher than that of the first metallic layer.
[0020] In accordance with a fourth aspect of the present invention, a recognizable soldering component having a relatively high solderability for connecting a package to a board is provided. The provided recognizable soldering component includes at least a first metallic layer and a second metallic layer located thereabove, wherein the respective colors of the first and the second metallic layers are different.
[0021] Preferably, the second metallic layer has an oxidation potential higher than that of the first metallic layer.
[0022] In accordance with a fifth aspect of the present invention, a method for enhancing a solderability of a soldering component is provided. The provided method includes steps of (a) providing a lead-free bump on a die; (b) providing a metallic layer on the lead-free bump so as to form the soldering component, wherein the metallic layer has an oxidation potential higher than that of tin; and (c) bonding the die to a substrate via the soldering component.
[0023] Preferably, in the step (b), the metallic layer is formed on the lead-free bump by means of dip coating, electrocoating, electroless coating, evaporation, sputtering or chemical vapor deposition.
[0024] Preferably, the metallic layer is formed of nickel (Ni), gold (Au), palladium (Pd), platinum (Pt) or silver (Ag).
[0025] In accordance with a sixth aspect of the present invention, a method for enhancing a solderability of a device is provided. The method includes steps of: (a) forming a metallic layer on a lead-free soldering component, wherein the metallic layer has an oxidation potential higher than that of tin; and (b) applying the lead-free soldering component for bonding a package to a board.
[0026] Preferably, in the step (a), the metallic layer is formed on the lead-free soldering component by means of dip coating, electrocoating, electroless coating, evaporation, sputtering and chemical vapor deposition.
[0027] Preferably, the metallic layer is formed of nickel (Ni), gold (Au), palladium (Pd), platinum (Pt) or silver (Ag).
[0028] Preferably, the soldering component is one selecting from a group consisting of a solder ball, a bump, a pin and a terminal electrode.
[0029] The foregoing and other features and advantages of the present invention will be more clearly understood through the following descriptions with reference to the drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a flowchart for illustrating steps of the method for enhancing the solderability for bonding a die to a substrate according to the present invention;
[0031] FIGS. 2 ( a ) and 2 ( b ) are diagrams illustrating a further application according to a first preferred embodiment of the present invention;
[0032] FIGS. 3 ( a ) and 3 ( b ) are diagrams illustrating a further application according to a second preferred embodiment of the present invention;
[0033] FIG. 4 is a diagram illustrating a further application according to a third preferred embodiment of the present invention;
[0034] FIG. 5 is a flowchart for illustrating steps of the method for enhancing the solderability for bonding a package to a board according to the present invention;
[0035] FIG. 6 is a diagram illustrating a further application according to a fourth preferred embodiment of the present invention;
[0036] FIG. 7 is a diagram illustrating a further application according to a fifth preferred embodiment of the present invention;
[0037] FIGS. 8 ( a ) and 8 ( b ) are diagrams for showing the respective result of solderability test for the conventional lead-free component and the novel lead-free component provided by the present invention; and
[0038] FIGS. 9 ( a ) and 9 ( b ) are diagrams for showing the respective appearance for the conventional lead-free component and the novel lead-free component provided by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed.
[0040] The present invention provides a novel method and the relevant device for enhancing the solderability. More specific, the present invention provides a method and a relevant lead-free device for enhancing the solderability and the wetting ability of the soldering component used therein, and thereby the lead-free device would be more recognizable and discernable so as to prevent the possible confusion while the lead-free procedures are introduced into the existing process.
[0041] In a preferred embodiment of the present invention, a typical dip coating is applied for depositing a metallic layer of a relatively high oxidation potential, i.e. an oxidation potential higher than that of tin (Sn), onto the surface of a lead-free solder component. Owing to the relatively high oxidation potential, the metallic layer is formable through a spontaneous replacement reaction occurring on the surface of the lead-free solder component, and thereby a passivation layer is fabricated so as to improve the anti-oxidation ability and thus the preservability of the lead-free device.
[0042] Please refer to FIG. 1 , which is a flowchart for illustrating steps of the method for enhancing the solderability according to the present invention. In this embodiment, preferably, the method is applied for bonding a die to a substrate. First, at least a lead-free bump is provided on the die, as shown in the step 11 . After activating the surface of the lead-free bump, a thin layer of gold is formed thereon by means of typical dip coating, as shown in the step 12 . Afterward, the die is bonded to a desired substrate via the lead-free bump having the thin layer of gold thereon, as shown in the step 13 , and thus the present lead-free soldering component having a relatively high solderability and anti-oxidation ability is fabricated.
[0043] In this embodiment of the present invention, it is preferred, but not restricted, to form a thin layer of gold on the surface of the lead-free bump. Moreover, the electrocoating, electroless coating, evaporation, sputtering and chemical vapor deposition (CVD) that are typically available for film deposition are also applicable and compliable with the method according to the present invention. In addition to the thin layer of gold, it is also applicable to deposit a thin layer of nickel (Ni), silver (Ag), palladium (Pd) or platinum (Pt) onto the surface of the lead-free bump for serving as the passivation layer thereof. For separating from the conventional lead-containing components in the process, a recognizable thin layer whose color is different from that of the bump is more preferable in this case.
[0044] Please refer to FIGS. 2 ( a ) and 2 ( b ), which are diagrams illustrating a further application according to a first preferred embodiment of the present invention. In this embodiment, the soldering component according to the present invention is combined with an underfill procedure for packaging. More specifically, the lead-free bump having a thin layer of gold dip-coated thereon 20 is applied for bonding a die 21 to a substrate 22 , and subsequently, the bonder 23 is dropped thereto, so as to fabricate a lead-free package structure 2 .
[0045] Please refer to FIGS. 3 ( a ) and 3 ( b ), which are diagrams illustrating a further application according to a second preferred embodiment of the present invention. In this embodiment, the soldering component according to the present invention is combined with a no-flow underfill procedure for packaging. In more specifics, the lead-free bump having a thin layer of gold dip-coated thereon 30 is applied for bonding a die 31 to a substrate 32 which is covered with the bonder 33 , so as to fabricate a lead-free package structure 3 .
[0046] The present invention is advantageous in that an additional preflux is applicable for further increasing the bonding reliability for the soldering component. Please refer to FIG. 4 , which is a diagram illustrating a further application according to a third preferred embodiment of the present invention. Similarly, the no-flow underfill procedure is adopted in this case for the die packaging. That is. the lead-free bump having a thin layer of gold dip-coated thereon 40 is applied for bonding a die 41 to a substrate 42 which is covered with the bonder 43 , so as to fabricate a lead-free package structure 4 . Moreover, in order to improve the bonding ability for the lead-free package structure 4 , a preflux layer 44 is pre-formed on the surface of the binding point of the substrate 42 . In addition to the preflux layer 44 , it is also applicable in the present invention for carrying out the procedures of such as immersion Sn, immersion Ag and ENIG (electroless nickel/immersion gold) or the procedure of organic solderability preservative (OSP) coating, so as to improve the preservability of the lead-free package structure.
[0047] Similarly, the method according to the present invention is also adoptable for mounting a package structure onto a desired board. Please refer to FIG. 5 , which is a flowchart for illustrating steps of the method for enhancing the solderability for assembling the package according to the present invention. In this embodiment, a lead-free soldering component for assembling the package is first fabricated from the lead-free solder, as shown in the step 51 . After the surface of the lead-free soldering component is activated, it is provided with a thin layer of gold thereon, as shown in the step 52 . Subsequently, the package structure is mounted onto a desired board, so as to fabricate the assembled lead-free device having a relatively high solderability and anti-oxidation ability, as shown in the step 53 .
[0048] In this embodiment, preferably, the lead-free soldering component is a bump, a solder ball, a pin or a terminal electrode. Moreover, the electrocoating, electroless coating, evaporation, sputtering and chemical vapor deposition (CVD) that are typically available for film deposition are also applicable and compliable with the method according to the present invention. In addition to the thin layer of gold, it is also applicable to deposit a thin layer of nickel (Ni), silver (Ag), palladium (Pd) or platinum (Pt) onto the surface of the lead-free soldering component for serving as a passivation layer thereof.
[0049] Please refer to FIG. 6 , which is a diagram illustrating a further application according to a fourth preferred embodiment of the present invention In this embodiment, the lead-free bump having a thin layer of gold dip-coated thereon 60 is applied for bonding a die 61 to a substrate 62 which is covered with the bonder 63 , so as to fabricate a lead-free package structure. Moreover, the lead-free package structure is assembled by means of flip-chip, so as to fabricate a lead-free device 6 . According to the present invention, the surface of the lead-free device 6 is further provided with a led-free terminal having a thin layer of gold coated thereon 65 , and thereby the lead-free device 6 is connected to a desired board 66 .
[0050] Please refer to FIG. 7 , which is a diagram illustrating a further application according to a fifth preferred embodiment of the present invention. In this embodiment, the pin 75 for connecting the lead-free package structure 70 to the desired board 76 is coated with a thin layer of gold, so that the anti-oxidation ability and the recognizability thereof would be significantly improved.
[0051] Please refer to FIGS. 8 ( a ) and 8 ( b ), which are diagrams for showing the respective result of solderability test for the conventional lead-free component and the novel lead-free component provided by the present invention. In comparison with the conventional lead-free component as shown in FIG. 8 ( a ), the lead-free component according to the present invention exhibits a more superior wetting ability, where the wetting reaction occurs in the whole test region of the substrate, as shown in FIG. 8 ( b ).
[0052] In the preferred embodiment, by performing a dip-coating with a commercial chemical of electroless gold for printed circuit board (PCB) under a temperature below 90° C. for approximately 10 minutes, a thin layer of gold having a thickness of approximately 0.25 μm would be obtained on the surface of the lead-free component. More specifically, since the oxidation potential of gold is higher than that of the base material, tin, of the lead-free component, a spontaneous replacement reaction would occur on the surface of the lead-free component upon dip-coating, and a thin layer of gold may thus formed thereon. Moreover, the thin layer of gold also provides an excellent protection for the lead-free component owing to its relatively high oxidation potential, and therefore, the ability in anti-oxidation of the lead-free component may significantly improved thereby. Furthermore, based on the test result, the lead-free component according to the present invention also exhibits a superior ability in wetting and an improved solderability.
[0053] Please refer to FIGS. 9 ( a ) and 9 ( b ), which are diagrams for showing the respective appearance for the conventional lead-free component and the novel lead-free component provided by the present invention. In addition to the mentioned efforts, the lead-free component according to the present invention is further advantageous in the recognizable appearance thereof since the color of gold is different from that of the conventional lead-containing component, whereby the process confusion could be prevented while the lead-free procedure is introduced in a conventional procedure. Hence, the present invention not only has a novelty and a progressive nature, but also has an industry utility.
[0054] While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to he accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
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A method and a device for enhancing the solderability of a lead-free component are provided. The provided method is compatible with the conventional soldering process and is capable of improving the wetting ability of the solder so as to enhance the solderability and the ability of anti-oxidation thereof. Besides, it is also achievable for providing a recognizable lead-free device so as to prevent the process confusion.
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This is a Continuation-in-Part of U.S. patent application Ser. No. 07/320,420 filed Mar. 8, 1989 now U.S. Pat. No. 4,956,127 issued Sept. 11, 1990.
FIELD OF THE INVENTION
The present invention pertains to gas-liquid contacting trays and, more particularly, an improved valve-tray assembly incorporating directional thrust valves and tray construction for higher efficiency operation.
HISTORY OF THE PRIOR ART
Distillation columns are utilized to separate selected components from a multicomponent stream. Generally, such gas-liquid contact columns utilize either trays, packing or combinations thereof. In recent years the trend has been to replace the so-called "bubble caps" by sieve and valve trays in most tray column designs, and the popularity of packed columns, either random (dumped) or structured packing have been utilized in combination with the trays in order to effect improved separation of the components in the stream.
Successful fractionation in the column is dependent upon intimate contact between liquid and vapor phases. Some vapor and liquid contact devices, such as trays, are characterized by relatively high pressure drop and relatively high liquid hold-up. Another type of vapor and liquid contact apparatus, namely structured high efficiency packing, has also become popular for certain applications. Such packing is energy efficient because it has low pressure drop and low liquid hold-up. However, these very properties at times make columns equipped with structured packing difficult to operate in a stable, consistent manner. Moreover, many applications simply require the use of trays.
Fractionation column trays come in two configurations: cross-flow and counter flow. The trays generally consist of a solid tray or deck having a plurality of apertures and are installed on support rings within the tower. In cross-flow trays, vapor ascends through the apertures and contacts the liquid moving across the tray, through the "active" area thereof. In this area, liquid and vapor mix and fractionation occurs. The liquid is directed onto the tray by means of a vertical channel from the tray above. This channel is referred to as the Inlet Downcomer. The liquid moves across the tray and exits through a similar channel referred to as the Exit Downcomer. The location of the downcomers determines the flow pattern of the liquid. If there are two Inlet Downcomers and the liquid is split into two streams over each tray, it is called a two pass tray. If there is only one Inlet and one Outlet Downcomer on opposite sides of the tray, it is called a single pass tray. For two or more passes, the tray is often referred to as a Multipass Tray. The number of passes generally increases as the required (design) liquid rate increases. It is the active area of the tray, however, which is of critical concern.
Not all areas of a tray are active for vapor-liquid contact. For example, the area under the Inlet Downcomer is generally a solid region. To attempt to gain more area of the tray for vapor/liquid contact, the downcomers are often sloped. The maximum vapor/liquid handling capacity of the tray generally increases with an increase in the active or Bubbling Area. There is, however, a limit as to how far one can slope the downcomer(s) in order to increase the Bubbling Area otherwise the channel will become too small. This can restrict the flow of the liquid and/or restrict the disengagement of vapor retained in the liquid, cause liquid to back up in the downcomer, and thus prematurely limit the normal maximum vapor/liquid handling capacity of the tray. The present invention specifically addresses the problem of restricted disengagement of vapor retained in the liquid.
A variation for increasing the Bubbling Area and hence vapor/liquid handling capacity is a Multiple Downcomer (MD) tray. There is usually a plurality of box shaped vertical channels installed in a symmetrical pattern across the tray to direct liquid onto and Off Of the tray. The downcomers do not extend all the way to the tray below but stop short of the tray by a predetermined distance which is limited by a sufficient space to permit disengagement of any vapor retained in the liquid entering the Exit Downcomer. The downcomer pattern is rotated 90 degrees between successive trays. The bottom of the boxes is solid except for slots that direct the liquid onto the Bubbling Area of the tray below, in between the outlet downcomers of the tray. The MD tray falls into the category of Multipass Trays and is usually used for high liquid rates.
Addressing now select cross flow plate designs, a particularly effective tray in process columns is the sieve tray. This tray is constructed with a large number of apertures formed in the bottom surface The apertures permit the ascending vapor to flow into direct engagement with the liquid that is flowing across the tray from the downcomer described above. When there is sufficient vapor flow upwardly through the tray, the liquid is prevented from running downwardly through the apertures (referred to as "weeping"). A small degree of weeping is normal in trays while a larger degree of weeping is detrimental to the capacity and efficiency of a tray.
Tray efficiency is also known to be improved in sieve type trays by increasing the froth height of the liquid and reducing the backflow of the liquid flowing across the tray. Froth is created when vapor bubbles percolate upwardly through the liquid flowing across the tray. The suspension of the vapor in the liquid prolongs the vapor liquid contact which enhances the efficiency of the process. The longer the froth is maintained and the higher the froth is established, the greater the vapor liquid retention. Higher froth requires smaller vapor bubbles and the formation of the bubbles at a sufficiently slow rate. Likewise, backflow occurs beneath the froth when circulating currents of liquid are established during the liquid flow across the plate. This generally forms along the lateral portions thereof. These currents carry liquid back across the tray in a manner that reduces the concentration-difference driving force for mass transfer. It is the concentration-difference between the vapor and the liquid which enhances the effectiveness of the vapor-liquid contact.
The concentration-difference between the vapor and the liquid can be effected in many ways; some reducing efficiency. For example, as operating pressure increases, descending liquid begins to absorb vapor as it moves across a tray. This is above that normally associated as dissolved gas as governed by Henry's Law and represents much larger amounts of vapor bubbles that are commingled or "entrained" with the liquid. This vapor is not firmly held and is released within the downcomer, and, in fact, the majority of said vapor must be released otherwise the downcomer can not accommodate the liquid/vapor mixture and will flood, thus preventing successful tower operation. This phenomena is generally deemed to occur when operating pressure is such as to produce a vapor density above about 1.0 lbs/cu. ft. and typically amounts to about 10 to 20% of the vapor by volume. For conventional trays, as shown below, the released vapor must oppose the descending frothy vapor/liquid mixture flowing over the weir into the downcomer. In many cases, such opposition leads to poor tower operation and premature flooding.
The technology of gas-liquid contact addresses many performance issues. Certain performance and design issues are seen in the publication "Ballast Tray Design Manual," Bulletin No. 4900-Fifth Edition by Glitsch, Inc., assignee of the present invention. Other examples are seen in several prior art patents, which include U.S. Pat. No. 3,959,419, 4,604,247 and 4,597,916, each assigned to the assignee of the present invention and U.S. Pat. No. 4,603,022 issued to Mitsubishi Jukogyo Kabushiki Kaisha of Tokyo, Japan. A particularly relevant reference is seen in U.S. Pat. No. 4,499,035 assigned to Union Carbide Corporation that teaches a gas-liquid contacting tray with improved inlet bubbling means. A cross-flow tray of the type described above is therein shown with improved means for initiating bubble activity at the tray inlet comprising spaced apart, imperforate wall members extending substantially vertically upwardly and transverse to the liquid flow path. The structural configuration is said to promote activity over a larger tray surface than that afforded by simple perforated tray assemblies. This is accomplished in part by providing a raised region adjacent the downcomer area for facilitating vapor ascension therethrough.
U S. Pat. No. 4,550,000 assigned to Shell Oil Company teaches apparatus for contacting a liquid with a gas in a relationship between vertically stacked trays in a tower. The apertures in a given tray are provided for the passage of gas in a manner less hampered by liquid coming from a discharge means of the next upper tray. This is provided by perforated housings secured to the tray deck beneath the downcomers for breaking up the descending liquid flow. Such advances in tray designs improve efficiency within the confines Of prior art structures. Likewise, U.S. Pat. No. 4,543,219 assigned to Nippon Kayaku Kabushiki Kaisha of Tokyo, Japan teaches a baffle tray tower. The operational parameters of high gas-liquid contact efficiency and the need for low pressure loss are set forth. Such references are useful in illustrating the need for high efficiency vapor liquid contact in tray process towers. U.S. Pat. No. 4,504,426 issued to Karl T. Chuang et. al. and assigned to Atomic Energy of Canada Limited is yet another example of gas-liquid contacting apparatus.
Several prior patents have specifically addressed the tray design and the apertures in the active tray deck area itself. For example, U.S. Pat. No. 3,146,280 is a 1964 patent teaching a directional float valve. The vapor is induced to discharge from the inclined valve in a predefined direction depending on the orientation of the valve in the tray deck. Such valve configurations are often designed for particular applications and flow characteristics. Tray valves with weighted sides and various shapes have thus found widespread acceptance in the prior art. A circular valve structure is shown in U.S. Pat. No. 3,287,004 while a rectangular valve structure is shown in U.S. Pat. No. 2,951,691. Both of these patents issuing to I. E. Nutter, teach specific aspects of vapor liquid contact flow utilizing tray valve systems. Such specialized designs are necessary because vapor-liquid flow problems must be considered for each application in Which a tray is fed by a downcomer. The type of directional flow valve, its orientation, and its predisposition to vapor-liquid flow interaction are some of the issues addressed by the present invention.
It would be an advantage to provide a method of and apparatus for enhanced vapor liquid flow manifesting increased efficiency with a directional thrust valve assembly. Such a valve tray assembly is provided by the present invention wherein a circular tray valve is supported by first and second support legs, oriented into the liquid flow of the tray with the first leg having a wider surface area presented to the flow for diverting the flow therearound. The width of the first leg is substantially less than the diameter of the circular valve aperture, about which the liquid is induced to flow into engagement with the vapor passing therethrough. This valve assembly, when used in conjunction with, and outwardly of, a raised active inlet area further controls initially directed liquid flow from the active inlet area beneath the downcomer.
SUMMARY OF THE INVENTION
The present invention relates to gas-liquid contacting trays and improvements in valve-tray assemblies. More particularly, one aspect of the invention includes an improved tray valve assembly for a process column of the type wherein liquid flows downwardly from a downcomer onto a first tray and thereacross in a first direction upon the active area thereof through which vapor flows upwardly for interaction and mass transfer with the liquid before passing therefrom. The improvement comprises a plurality of apertures formed in the tray having a valve cover mounted thereon. The valve cover is mounted by first and second legs, the first leg being disposed to intercept the flow of liquid across the tray and being wider than the second leg. The legs are mounted to the tray in outwardly slotted portions thereof for defining the orientation of the valve relative to the liquid flow. A number of valve shapes are contemplated by the present invention. These include oval and triangular valves. The valve also includes means for selectively biasing the rear region of the valve upwardly against the flow of liquid for facilitating initial, directionalized vapor flow therethrough.
In another aspect, the invention includes the above described tray valve being formed of a round disc having the first and second legs depending downwardly therefrom. Each of the legs are formed with outwardly extending flange portions for underlying the tray and locking the disc in a floating relationship relative thereto. The valve aperture is circular in shape and the valve legs are disposed in slotted regions disposed outwardly of the circular aperture to prevent the rotation of the valve plate for maintaining the orientation of the valve leg relative to the tray. The biasing means comprises a detent portion formed on the cover of the valve for preventing the surface thereof from resting flush against the tray surface. This design facilitates the initial passage of vapor through the valve. The valves are also comprised of circular discs mounted in and above circular apertures formed in the active tray area. Certain ones of the valves are oriented for the directional thrust of vapor therethrough in a select orientation that is not parallel to the initial flow of liquid thereacross for imparting a directional thrust to the liquid flow. In this manner, the direction of liquid flow can be effected, which further enhances the effectiveness of a raised active inlet area adapted for the discharge of vapor into the liquid coming from a downcomer for passage onto the valve area.
In another aspect, the invention includes an improved method of mixing vapor with liquid discharged from a downcomer of a process column onto an underlying cross-flow tray with the column having a plurality of trays and downcomers spaced vertically one from the other. The improvement comprises forming the tray with a plurality of directional thrust valves disposed therein, the valves being formed of generally circular disc members disposed above circular apertures formed within the tray. The disc members have first and second legs in support thereof, the first leg being wider than said second leg for directing flow therearound, the first and second legs of the valve are disposed along a line perpendicular to the downcomer and generally parallel to the flow therefrom. The step of forming the disc members includes biasing the frontal end of the disc which first engages the liquid flow downwardly relative to the rear end for facilitating the directional flow of vapor therethrough.
In another aspect of the invention, the method described above includes the step of forming the first and second legs of the valve with flange portions outstanding from the disc and engaging the underside of the tray to prevent the lifting of the valve upwardly therethrough. The circular aperture may be formed with first and second notches therein, the first and second notches receiving the first and second legs therein and preventing the rotation of the disc relative to the tray.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a packed column with various sections cut away for illustrating, diagrammatically, a variety of tower internals and one embodiment of a downcomer-tray assembly constructed in accordance with the principles of the present invention disposed therein;
FIG. 2 is a diagrammatic, side-elevational, cross-sectional view of the improved downcomer-tray assembly of the present invention secured within a process tower and illustrating the flow of liquid and vapor thereacross;
FIG. 3 is a top-plan, diagrammatic view of a prior art tray illustrating problems with the liquid flow thereacross;
FIG. 4 is a perspective view of the downcomer-tray assembly of the present invention, with portions thereof cut away for purposes of clarity;
FIG. 5 is an enlarged, perspective view of one valve of the tray surface disposed adjacent the downcomer of the present invention;
FlG. 6 is an enlarged, side-elevational, cross-sectional view of the valve structure of FIG. 5; and
FIG. 7 is a perspective view of an alternative embodiment of the valve structure of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, there is shown a fragmentary, perspective view of an illustrative packed exchange tower or column with various sections cut away for showing a variety of tower internals and the utilization of one embodiment of the improved high capacity tray assembly of the present invention. The exchange column 10 of FIG. 1 comprises a cylindrical tower 12 having a plurality of packing bed layers 14 and trays disposed therein. A plurality of manways 16 are likewise constructed for facilitating access to the internal region of the tower 12. Also provided are side stream draw off line 20, liquid side feed line 18, and side stream vapor feed line or reboiler return line 32. A reflux return line 34 is provided atop the tower 10.
In operation, liquid 13 is fed into the tower 10 through reflux return line 34 and side stream feed input feed line 18. The liquid 13 flows downwardly through the tower and ultimately leaves the tower either at side stream draw off 20, or at bottom stream draw off line 30. In its downward flow, the liquid 13 is depleted of some material which evaporates from it as it passes through the trays and packing beds, and is enriched or added to by material which condenses into it out of the vapor stream.
Still referring to FIG. 1, the exchange column 10 is diagrammatically cut in half for purposes of clarity. In this illustration, the column 10 includes a vapor outlet in overhead line 26 disposed atop the tower 12 and a lower skirt 28 disposed in the lower region of the tower around bottom stream takeoff line 30 coupled to a reboiler (not shown). Reboiler return conduit 32 is shown disposed above the skirt 28 for recycling vapor therein upwardly through the trays and/or packing layers 14. Reflux from condensers is provided in the upper tower region 23 through entry conduit 34 wherein reflux is distributed throughout a liquid distributor 36 across upper packing bed 38. It may be seen that the upper packing bed 38 is of the structured packing variety. The regions of the exchange column 10 beneath the upper packing bed 38 are shown for the purpose of illustration and include a liquid collector 40 disposed beneath a support grid 41 in support of the upper structured packing 38. A liquid distributor 42, adapted for redistributing liquid 13, is likewise disposed there-beneath. A second type of distributor 42A is shown below the cut-line 43 and disposed above bed 14. The column 10 is presented with cut-line 43 for illustrating the fact that the tower internals arrangement is diagrammatical only and is provided for referencing various component arrays therein.
Referring still to FIG. 1, an assembly of a pair of trays is also shown for purposes of illustration. In many instances, process columns contain only packing, only trays, or combinations of packing and trays. The present illustration is, however, a combination for purposes of discussion of the overall tower and its operation. A trayed column usually contains a plurality of trays 48 of the type shown herein. In many instances, the trays 48 are valve or sieve trays. Valve trays, comprising the subject matter of the present invention, are herein shown. Such trays comprise plates which are punched or slotted in construction. The vapor and the liquid engage at or along the tray and, in some assemblies, are permitted to flow through the same openings in a counter-current flow arrangement. Optimally, the vapor and liquid flows reach a level of stability. With the utilization of appropriate downcomers, to be described in more detail below, this stability may be achieved with a relatively low flow rate permitting the ascending vapor to mix with the descending liquid. In some embodiments, no downcomers are used and the vapor and the liquid use the same openings, alternating as the respective pressures change. But such is not the case, as shown herein.
In the present embodiment, cross-flow valve trays 48 and 49 and downcomers 53 and 69 are illustrated. Tray 48 is constructed with a plurality of floating valves. Tray 49 also illustrates a raised inlet section 51 beneath downcomer 53, which in accordance with the present invention is substantially planar, formed with a plurality of apertures and which may include a series of momentum deflector barriers, as will be described below. The raised inlet area is described in more detail in U.S. patent application Ser. No. 320,420. Corrosion is another consideration in designing packed towers and for the selection of the material, design, and the fabrication of the tower internals The anatomy of process columns as shown in FIG. 1 is likewise described in more detail in an article by Gilbert Chen, entitled "Packed Column Internals" appearing in the Mar. 5, 1984 edition of Chemical Engineering, incorporated herein by reference.
Referring now to FIG. 2, there is shown a side-elevational, cross-sectional, diagrammatic view of the trays 48 and 49 of FIG. 1 and several design aspects of the present invention. An upper tray 48 comprises a first valved panel. The lower tray 49 is also of generally planar construction across its central active area 52, having a plurality of valves 100 mounted therein, as diagrammatically shown. Liquid 13 travels down a downcomer 53 having a tapered or mitered bottom section 54, from tray 48 disposed thereabove. The tapered section 54 of the downcomer provides a clearance angle for vapor flow from the active inlet area, which clearance angle affords a horizontal flow vector to the vapor vented through raised panel 51. The liquid 13 engages vapor 15 discharged from the raised active panel area 51 beneath the downcomer 53.
Still referring to FIG. 2, the froth 61 extends with a relatively uniform height, shown in phantom by line 63 across the width of the tray 49 to the opposite end 65 where a weir 67 is established for maintaining the froth height 63. The accumulated froth at this point flows over the top of the weir 67 into associated downcomer 69 that carries the froth downwardly into a mitered region 70 Where the liquid accumulates and disperses upon active inlet region 71 therebeneath. Again active inlet region 71 is shown herein diagrammatically for purposes of illustration only. As stated herein, the area of holes and perforations for a single cross-flow plate establish the active length of the plate and the zone in which the froth 61 is established. It should be noted that the present invention would also be applicable to multiple downcomer configurations, Wherein the downcomers and raised, active inlet areas may be positioned in intermediate areas of the trays as also described below. By increasing the total active area by active inlet areas 51 and 71 greater capacity and efficiency is achieved. It is also the manner of flow of the liquid 13 across the tray 49 which, in the present embodiment, is critical to tray efficiency. A flow diagram of a conventional tray will be discussed below for purposes of illustrating the efficiency afforded by the present invention.
Referring now to FIG. 3, there is shown a flow diagram across a conventional tray. The prior art tray 72 is illustrated herein as a round unit having a first conventional downcomer for feeding liquid upon a solid, underlying panel 73 and then to the tray 74. A second downcomer 74A carries liquid away from the tray. A plurality of arrows 75 illustrate the non-uniform flow of liquid 13 typically observed ac ross a conventional prior art tray which does not address the circulation issue. Circular flow is shown to be formed on both sides of the plate lateral to the direction of primary flow. The formation of these retrograde flow areas, or recirculation cells 76, decreases the efficiency of the tray. Recirculation cells 76 are the result of retrograde flow near the walls of the process column and this backflow problem becomes more pronounced as the diameter of the column increases. With the increase in retrograde flow and the resultant stagnation effect from the recirculation cells, concentration-difference driving force for mass transfer between the counter-flowing streams is reduced. The reduction in concentration-difference driving force will result in more contact or height requirement for a given separation in the column. Although back mixing is but a single aspect of plate efficiency, the reduction thereof is provided concurrently with the other advantages hereof. Reference is again made to the plate efficiency discussion set forth in above referenced, co-pending patent application Ser. No. 07/304,942, now U.S. Pat. No. 4,956,127 issued Sept. 11, 1990.
Referring now to FIG. 4, there is shown an enlarged, fragmentary perspective view of a downcomer-tray assembly 99 constructed in accordance with the principles of the present invention. Conventional materials such as stainless steel are utilized, as is well known in the art. The tray 49, as shown herein, is also constructed for placement in the tower 12 by conventional means. In the tower, a feeding downcomer 102, having an inclined face 103, is disposed over a raised inlet region 104 for discharging liquid 3 to tray 49. A weir 82 is disposed on the opposite side of tray 49 whereby a second downcomer is disposed for carrying liquid 13 away from the tray 49. Liquid 13 spills down upon active inlet panel 104 and over upstanding edge 106 onto the tray 49.
Still referring to FIG. 4, there is shown the top surface 108 of raised inlet region 104, constructed with a plurality of apertures 110 diagrammatically shown herein and more fully set forth and described in co-pending U.S. patent application Ser. No. 330,420. The apertures 110 are, in certain areas, partially eliminated or blocked off by barrier strips 101, more fully described in co-pending U.S. application Ser. No. 330,420 filed concurrently herewith. Barrier Strips 101 comprise strips of metal (blanking strips tack welded to the surface 108 in defined patterns. The strips 101 comprise momentum barriers and are seen to be provided in groups 112. Particular momentum barrier group 114 is disposed adjacent the edge of the column 12 with an intermediate group 116 disposed inwardly thereof. The strips 01 of group 116 are seen to be substantially longer than those of group 114 as will be discussed in more detail below.
Referring still to FIG. 4, the groups 112 are sized and positioned in a mirror image of the orifices 118 of feeding downcomer 102. The orifices 118 are likewise provided in groups 120 wherein end group 122 is disposed immediately above momentum barrier group 114. Likewise, intermediate group 124 is disposed directly above momentum barrier group 116. The orifices 118, including groups 122 and 124, form the bottom 126 of downcomer 102 in a slotted configuration that is presented to more precisely distribute the liquid flow onto the surface of the tray 49. This feature provides a more uniform flow without the retrograde problem discussed above. By utilizing select groupings of apertures such as elongated slots 118 which are selectively spaced into groups 120, the discharge from downcomer 102 can be selectively designed by those skilled in the art to enhance uniform flow across the float valve tray described herein and reduce back mixing therein. The reduction of back mixing will increase the concentration-difference driving force for mass transfer between the counter flowing streams of gas and liquid. The directional thrust valves 100 of the present invention facilitates this efficiency in operation.
Referring now to FIG. 5, there is shown a single float valve 100 of the array shown in FIG. 4. The valve 100 of the present embodiment is comprised of a circular disc 130 having securement feet 132 and 134 depending therefrom. The valve 100 is mounted within the surface of tray 49 and disposed above an aperture 136 formed therein. The aperture 136 includes a pair of slotted regions 138 and 139 adapted for receiving the legs 132 and 134, respectively. There are multiple advantages in utilizing this type of floating valve. The orientation of the valve relative to the liquid flow is determined by the spacing of the slotted regions 138 and 139 which allows for not only the upward flotation of the circular disc 130 for the passage of vapor therebeneath, but also the secured orientation thereof.
The size of the valve 100 as shown herein is on the order of one inch in diameter. This size has been shown to be effective in the assembly of a tray having an active area with approximately 25-50 valves per square foot. This valve density per square foot is substantially higher than possible with valves of the conventional size of 11/2" to 17/8" in diameter. Prior art valve density on the order of 12-14 valves per square foot has been common. The increased density is a result of the smaller size of valve 100 and its directional thrust design as herein described, which permits it to be spaced close to adjacent valves as shown. The present invention is a marked advance over prior art designs utilizing larger valves and broader spacing. The efficiency of the tray is thought to be enhanced therefrom.
Still referring to FIG. 5, liquid flow 140 is illustrated flowing in the direction of disc 130. As the liquid flow 140 engages the frontal leg number 132, it is seen to split into bi-directional flow 141 traveling around the circumference of the circular aperture 136. Vapor 15 venting beneath circular disc 130 is represented by arrows 142, which arrows illustrate the biased direction that the vapor 15 has in discharge from beneath the disc 130, due to both the frontal leg number 132 as well as the liquid flow 140 and 141 which is engaged thereby. Both the shape of the hole as well as the discharge of vapor 15 therein works in conjunction with the enlarged frontal member 132 to enforce the split flow 141 as described above. In this manner the float valve 100 is effective in reducing the amount of liquid which is back-trapped, or captured, into the aperture 136. The passage of liquid into the aperture 36 is a distinct disadvantage in that such leakage causes the liquid to bypass the remaining active area of the tray deck. It is most advantageous to have a valve structure that limits the amount of liquid flow that is captured within such apertures.
Referring still to FIG. 5, it may further be seen that the select orientation of the valve induces the vapor flow 142 to be in a direction substantially along the path of the liquid flow 140 to help to further promote the directional flow of liquid. This "directional thrust" aspect of the valve is provided due to the size of the frontal leg 38 and the shape of the aperture 136 intersecting liquid flow in direction 40. Such controlled flow aspects may be utilized to further reduce the problem of retrograde liquid flow discussed above. In some situations the orientation of the valve may be slightly angulated relative to the inlet panel 104 for purposes of initiating a degree of directional thrust from the vapor discharge 142. With the present round aperture 136, the frontal leg 132 may also be substantially narrower than if the aperture 136 were rectangular in shape due to the fact that the arcuate shape facilitates the bi-directional liquid flow 141 therearound. In this particular configuration, the frontal leg 132 comprises approximately 30% of the frontal area of the aperture 136 which engages flow 140. With the 30% frontal area of leg 132, and round hole 136, back-trapping is substantially reduced. Moreover, with the tangential flow diversion 141, the degree of turbulence is substantially reduced as compared to a flat barrier structure that would interrupt the liquid flow and produce turbulence therefrom. It should be noted, however, that shapes other than round, or circular valves may also be used.
Referring now to FIG. 6 there is shown the valve 130 of FIG. 5 in a side elevational, cross section view. Frontal leg member 132 is seen to provide a movable barrier for engaging the liquid flow 140 coming from the raised inlet area 104 (not shown). Vapor 15 ascending through the tray deck 49 is exhausted as represented by arrows 42. The escaping vapor 142 interacts immediately with liquid flow 140 and 141, as described above, the latter liquid flow 141 being diverted around the edges of the circular aperture 136. The liquid flow then continues downstream of rear leg 134 as represented by arrow 144. The directional thrust aspect as described above may also be provided in conjunction with the difference in weight between the frontal leg 132 and rear leg 134. The wider frontal leg 132 will, at low vapor flow rates, allow the rear portion of disc 130 to rise upwardly in direction of arrow 134A. This upwardly initiated movement is further facilitated by the detent, or indentation 135 formed adjacent the rear leg 134. The indentation 135 creates a slight bias in the downstream side of the disc 130 to the upward position. This bias creates a slight angulation for the disc 130 in its resting position. The angulated position serves to initiate the upward movement of the rear leg 134 from the resting position and may incorporate a detent 135 on both sides of leg 134. Detents have been used in the prior art to keep valves from sticking to the tray surface. In the present invention the indentation 135 is utilized in conjunction with the particular valve assembly shown herein for select orientation and preferential biasing of the thrust of the directional thrust valve herein described.
Referring now to FIG. 7 there is shown a stationary upstanding aperture cover 146 having the advantages of the two-leg, slotted orientation, wherein the lead leg 148 is wider than the rear leg 148A. In this alternative embodiment of a stationary cover 146, upstream leg 148 is both angulated and permanently formed in active tray section 149 to facilitate the diversion of liquid flow therearound in the direction of arrows 150. The method of formation may include punching, and/or stamping, which is conventional metal forming technology. This figure is provided for purposes of illustrating one aIternative form of tray aperture covers that may be incorporated in accordance with the principles of the present invention.
It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. For the method and apparatus shown or described has been characterized as being preferred it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims.
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A valve-tray assembly for vapor liquid contact towers. The active area of the tray beneath an upper downcomer is constructed with directional thrust valves facilitating oriented vapor flow therethrough and improving mass transfer efficiency. The valves include first and second support legs oriented into the liquid flow with the first leg having a wider surface area presented to the flow for diverting the flow therearound. The width of the first leg is less than the diameter of the valve aperture, about which the liquid is induced to flow into engagement with the vapor passing therethrough. The valve assembly is used in conjunction with, and outwardly of, a raised active inlet area to further control initially directed liquid flow from the perforated inlet area beneath the downcomer.
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FIELD OF THE INVENTION
The present invention relates to decorative items, such as centerpieces, and decorations including toppers placed on cakes for decorative purposes.
BACKGROUND OF THE INVENTION
Decorations for festive purposes are widely used. One form of decoration for events celebrated between people is a small figure of a couple. This depiction can be in the form of an ornament, centerpiece or, most commonly, a cake topper.
Since shortly after cakes were decorated for festive purposes, decorations have included figures placed on the tops of cakes. One of the most popular decorations has been the use of a unitary decoration of a bride and groom on a wedding cake.
However, the decorations which are commercially available are limited in variety and aesthetic appeal. They are generic designs which cannot be modified or customized with the particulars of a specific couple.
As such, it is an object of the present invention to provide a decoration which can be customized to the particulars of an occasion and/or couple.
It is a further object to make figures interchangeable to form components of a decoration.
It is an additional object to make features of a figure interchangeable to further customize a decoration.
It is also an object to provide a method of manufacture to provide custom decorations.
SUMMARY OF THE INVENTION
These and other objects are achieved by the decoration of the present invention which comprises a first figure and a second figure, said first figure and second figure being preconfigured or preformed into corresponding interactive poses wherein one of a variety of first figures are able to mate with one of a variety of second figures in an interchangeable fashion to provide a custom user determinable pairings. Thus the invention allows for a great variety of possible pairings with a fairly limited number of individual first and second figures.
The first and second figures preferably have coupling means so that the figures can be maintained in a fixed interactive relationship.
Also, the first and second figures may have interchangeable features. For example, one or both of the figures may have an interchangeable head so that the look of the head on the body can be customized.
Additionally, an optional base is contemplated on which the desired first and second figures can stand. It is preferred that such base include engagement means for engaging at least one of the first or second figure, with a keyed engagement means being most preferred. The engagement means not only acts as an attachment between the base and the figures but also acts as a positioning means to ensure that the figures are properly positioned on the base.
Moreover, the figures may have additional features which can be interchanged. For example, one of the figures may have retention means for holding another featured item such as a bouquet of flowers, a baby, a dog, etc.
The present invention further contemplates custom accessories, including columns which can be adapted to stand individually, to contain a flower arrangement or to be connected by interconnecting means. Adaptability is provided by use of interchangeable components which engage the columns.
BRIEF DESCRIPTION OF THE DRAWINGS
The attached drawings, in which like reference characters represent like parts, are provided for illustration purposes only and are not intended to limit the present invention in any manner whatsoever.
FIG. 1 is an exploded perspective view of the preferred embodiment of the customizable figures of the present invention.
FIGS. 2A and 2B are examples of possible first figures for use in the present invention.
FIGS. 3A, 3B, 3C and 3D are examples of possible second figures for use in the present invention, with FIG. 3C being an exploded view.
FIG. 4 is a partial exploded perspective of the preferred coupling means between the first and second figures of the present invention.
FIG. 5 is a partial exploded perspective of the preferred engagement means between the base and a figure of the present invention.
FIGS. 6A-6C are examples of possible male heads in perspective for use on the first or second figures, or both, depending on the figure(s) being male.
FIGS. 6D-6F are examples of possible female heads in perspective for use on the first or second figures, or both, depending on the figure(s) being female.
FIGS. 7-9 are examples of various combinations of first and second figures in elevation which are contemplated using the present invention.
FIG. 10 is an elevational view of a preferred column accessory contemplated in the present invention.
FIG. 11 is an exploded view of the column of FIG. 10.
FIG. 12 is an elevation of the column accessory having an alternative decorative element.
FIG. 13 is a partial cross section of the upper portion of the column accessory with an alternative decorative element.
FIG. 14 is a plan view of the decorative element of FIG. 13.
FIGS. 15A-15D are examples of column arrangements and interconnecting decorative elements contemplated by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In its preferred embodiment the present invention comprises a decoration 2 with at least two figures, a first FIG. 4 and a second FIG. 6 (see FIGS. 1 and 7-9). The FIGS. 4 and 6 are preformed in fixed poses such that one of the various first FIGS. 4 can be interchangeably coupled with one of the various second FIGS. 6, providing for a number of customized pairings.
Preferably, but not necessarily, the figures are placed on a base 8. The base 8 preferably has a mounting pin 10, for holding and positioning the figures on the base 8, which cooperates with a mounting aperture 12 on the bottom of the first FIG. 4. In its most preferred embodiment the mounting pin 10 and mounting aperture 12 are keyed but at a 90° offset. For mounting, the mounting aperture 12 receives the mounting pin 10 and the first FIG. 4 is rotated 90° into its presentation position. Of course, the keyway may be cammed to provide a snug attachment of the first FIG. 4 to the base 8.
To maintain the FIGS. 4 and 6 in a fixed or semi-fixed paired relationship, the FIGS. 4 and 6 have cooperating coupling means. As best shown in FIG. 4, the first FIG. 4 has coupling detent 14 which engages a receiving aperture 16 to maintain the paired relationship. The detent 14/aperture 16 can be a force fit, held by friction, or there can be snap-fit or locking structures as are well known in the art.
To facilitate the interchangeable aspect of the first and/or second figures, each of the first FIGS. 4 have a right hand with the coupling detent 14 at a predetermined location. Similarly, the first FIGS. 4 have a left hand extending across the body to accept the cooperating hand of the second FIG. 6 (see FIGS. 2A and 2B).
To cooperate with the first FIG. 4, each second FIG. 6 has a coupling aperture 16 at a predetermined location associated with the location of the coupling detent 14 of the first FIG. 4. Also, on the second FIGS. 6 the left hand is positioned to engage the left hand of the first FIG. 4.
The right hand of the second FIG. 6 can be holding an object such as a bouquet, a baby, etc. or merely positioned along the body, across the body or in the lap, etc. (see FIGS. 3A-3D). The object 36 in the right hand of the second FIG. 6 may have attachment means 38, similar to that described and shown in FIG. 4, so that it is removable and replaceable to provide a variety of user determinable featured elements. In one option contemplated herein, an older child can be positioned in front of the second FIG. 6 and the engagement means can maintain its position, much like the coupling detent 14/aperture 16 between the first and second FIGS. 4 and 6.
The interchangeability of the first and second FIGS. 4 an 6 allows for a variety of pairings. For example, FIG. 7 shows two female FIGS. 4 and 6, FIG. 8 shows two male FIGS. 4 and 6 and FIG. 9 shows a first FIG. 4 standing and a second FIG. 6 in a wheelchair. Of course, many possible variations of combinations exist, including variations for height, weight and outfit of the figures, i.e. in pants, short and long dresses, etc.
Additionally, as shown in FIG. 1, the heads 18 of the figures can be interchangeable to provide a variety of different features. In the most preferred embodiment, the male heads 18a have a shaft-like neck to fit into a collar (see FIGS. 6A-C). The female heads 18b have a neck which continues down to the upper chest to fit into a dress (see FIGS. 6D-F).
Examples of differences in the heads include a white male in FIG. 6A, a black male in FIG. 6B and a bald male in FIG. 6C. Similarly, FIG. 6D shows a white female, FIG. 6E a black female and FIG. 6F an asian female. Of course, other adaptations can be made in the style or length of hair, the inclusion of beards or moustaches, etc. Moreover, the use of animal heads for the figures, such as dogs and cats, can be provided as novelty items for animal lovers.
Other accessories are also contemplated, such as veils, top hats and the like. These can be placed on or around the figures using common techniques known in the art.
Additional decorations with interchangeable aspects are also contemplated as part of the present invention, including a column 20 which can be used alone or with interchangeable elements. In the preferred embodiment (shown in FIGS. 10 and 11) the column 20 would be made of a pedestal 24, a post 26, a cup 28 and a cap 30 which are fit together. A peg 22 is also shown in FIGS. 10 and 11 to provide stability when the column 20 is used on a cake.
As shown in FIG. 12 the cap 30 can be replaced by a flower arrangement 32 or the like to fill the cup portion of the column 20. If desired, the cup 28 can be filled with water or dirt to use real flowers or even have a styrofoam core into which fake flowers can be positioned.
Similarly, one or more column bridges 34 can be used to connect adjacent columns 20 (see FIGS. 13 and 14). Of course, the number of columns 20 can vary. As shown in FIGS. 15A-D, two to four columns 20 are shown with bridges 34 between each, although plain columns 20 or columns 20 with flower arrangements 32 can be also used.
It is contemplated that the present invention will be made of plastic and, preferably, injection molded. Of course, the invention can be made of porcelain, metal or any other suitable material.
Additionally, the elements of the present invention can also be permanently attached, by snap fitting the elements with glue, epoxy or the like once the selections of the user are made. Moreover, the invention can be further customized by coating or painting the elements to select such specifics as, for example, hair color, complexion, clothing colors, and the like, or providing an overall glaze.
Finally, obvious variations of the invention described herein will make themselves apparent to those skilled in the art, all of which are intended to fall within the spirit and scope of the invention, limited only by the appended claims.
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A decoration having cooperating first and second figures so that a variety of first figures can be combined with a variety of second figures for a customized pairing. Further customizing is enabled with the use of interchangeable heads. A base for the figures and adaptable decorative columns can be added.
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TECHNICAL FIELD
[0001] The present invention relates to a multi-channel wireless communication system in which one base station uses a plurality of channels to configure a cell for accommodating a wireless communication terminal.
BACKGROUND ART
[0002] Generally, licenses of frequencies are managed by the government and only licensed persons can use the frequencies in specific places and time under strict management. Demands for the wireless frequencies as finite resource are increasing and a lack of allocatable frequencies is problematic around the world.
[0003] Therefore, in recent years, a method has been studied for using a frequency band (white space) which is not used spatially and temporally irrespective of being already assigned as a using method of new frequency in order to solve the problem of exhausted frequencies. A cognitive wireless technique is used such that while effects on the use of frequencies in existing systems of the licensed users (which will be denoted as “primary users” below) are sufficiently avoided, non-licensed users (which will be denoted as “secondary users” below) flexibly use a white space.
[0004] In a method for correctly recognizing which frequency channel is in a white space, a database (DB) server for managing a list of white space channels (WSCH) and providing positional information, antenna height or antenna directivity, gain and the like is installed over the Internet such that each wireless station can access the same directly or via a proxy server. Each wireless station acquires its own WSCH list (list of available frequency channels), maximum transmittable power corresponding to each WSCH, available period, and the like from the DB server.
[0005] In other method, each wireless station senses a radio wave used by a primary system with spectrum sensing, and when confirming the absence of a radio wave, enables a frequency channel of the primary system to be used as a white space, and when sensing the presence thereof, excludes the channel from its WSCH list.
[0006] There is known IEEE 802.22 (see Non-Patent Literature 2) as an international standard-setting organization of wireless communication systems using a white space. FIG. 1 illustrates a system structure of the IEEE 802.22-2011 (simply called 802.22 below). The system is such that one base station (BS) and one or more pieces of customer premises equipment (CPE) configure a cell, and avoids interference on the primary system by an access to a DB server 6 via the Internet 5 thereby to realize secondary use.
[0007] The management or setting of a channel operated by the 802.22 system is controlled by a spectrum manager (SM) in the base station, and the SM sets priorities on the WSCH to select one operating channel for use based on a DB access result (WSCH list for BS) acquired by a management information base (MIB), a spectrum sensing result and positional information.
[0008] Exemplary operations of the 802.22 system will be described below with reference to FIG. 2 .
[0009] When being powered on and activated, a BS acquires a WSCH list by an access to the DB server 6 and spectrum sensing, and selects one channel as operating channel from the WSCH list thereby to start operation. That is, a wireless signal is exchanged at a frequency of the operating channel.
[0010] When starting operation, the BS broadcasts control information to a service area (cell). The 802.22 employs a structure in which 16 frames are assumed as one superframe as illustrated in FIG. 3 , and the BS periodically transmits SCH (Superframe Control Header) as superframe control information, FCH (Frame Control Header) as frame control information, DS-MAP (Downstream Map) or US-MAP (Upstream Map) to manage and control the cell.
[0011] When being powered on, CPE confirms a channel at which a primary system is absent by sensing, and then tries to receive a BS signal (SCH) while switching frequencies in a BS search processing. (Sensing may be included in the BS search processing or sensing may be performed on the channel after a BS signal (SCH) is sensed.)
[0012] When successfully receiving SCH from the BS, and additionally receiving the frame control information such as FCH, DS-MAP or US-MAP, the CPE can correctly recognize the structure in the frame thereby to perform a synchronization processing such as adjustment of signal transmission/reception timing or transmission power between BS and CPE, or procedures such as registration, authentication and service allocation of CPE terminal information (ID, positional information, maximum transmission power). At this time, CPE presents its positional information, thereby asking BS whether the incumbent operating CH is available as its WSCH.
[0013] When connection between the BS and the CPE is established, data communication is performed under control of the BS. The 802.22 employs OFDMA (Orthogonal Frequency Division Multiple Access) for multiple access system and TDD (Time Division Duplex) for complex communication system.
[0014] While the BS performs data communication, it updates the WSCH list by DB access or sensing periodically or as needed, and at this time, when the BS determines that the operating channel is not available, a channel switch processing is performed to switch the channels in the entire cell. When only specific CPE cannot use an incumbent operating channel, only the CPE is disconnected, and a determination to continue the operation at the channel may be made depending on a BS operation policy.
[0015] While the CPE performs data communication, it performs sensing periodically or in response to an instruction from BS, and when CPE senses a primary system at the operating channel, it notifies the information to the BS. The BS performs channel switching with the notification as a trigger. When the CPE cannot receive a signal from the BS over a certain period of time due to failed reception of a control message such as channel switch request from the BS, the CPE achieves the channel switching in the BS search processing.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: US Patent Application No. 2011/0039593
Non Patent Literature
[0000]
Non-Patent Literature 1: Kouji FUJII, “Cognitive radio: Core technique for utilizing white space in order to eliminate waste of radio waves”, [online], RIC TELECOM, [searched on Jun. 9, 2011], the Internet <URL: http://businessnetwork.jp/tabid/65/artid/110/page/1/Default.aspx>
Non-Patent Literature 2: The Institute of Electrical and Electronics Engineers (IEEE) Computer Society, “IEEE Std 802.22-2011 Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Policies and Procedures for Operation in the TV Bands”, (US), the IEEE standardization society, Jul. 27, 2011
SUMMARY OF INVENTION
Technical Problem
[0019] Non-Patent Literature 2 (IEEE 802.22-2011) was established with the aim of providing wireless broadband communication services to CPE. However, when many pieces of CPE are connected, a communication service cannot be provided with excellent quality. A revised 802.22 has been currently discussed with one aim of aggregating bit rates in consideration of future demands for communication services with wider bands.
[0020] However, the operating channel determination means in Non-Patent Literature 2 does not assume that a plurality of channels are used as operating channels. Therefore, if Non-Patent Literature 2 is simply extended, various unreasonable things are caused, which is problematic in terms of effective use of white space, provision of high-seed communication to users, low-cost construction of system, and the like.
[0021] The present invention has been made in order to solve the above problems, and it is an object thereof to enable WSCH to be dynamically used and to realize high-speed communication while effectively using a white space in a multi-channel wireless communication system including a plurality of base stations (BS) in which cells for accommodating wireless communication terminals (CPE) are configured by use of a plurality of channels, respectively.
Solution to Problem
[0022] According to one aspect of the present invention, there is provided a multi-channel communication system including a base station including a plurality of wireless communication units and an intensive control unit, and one or more terminal stations each including a plurality of wireless communication units and an intensive control unit, wherein when a base station operates one or more channels depending on a situation of a white space channel and allocates them to the terminal stations thereby to operate a plurality of channels, communication is performed in a robust mode of duplicating and allocating data on the terminal stations to the channels, or a high-seed mode of dividing and allocating data.
[0023] According to another aspect of the present invention, the intensive control unit in the base station includes a channel addition means for allocating operating channels to the wireless communication units in the base station, a means for switching operating channels in the wireless communication units, a means for stopping operating channels in the wireless communication units, a means for making a channel allocation determination on the terminal stations, a means for performing a transmission data allocation processing and making a data transmission instruction to the wireless communication units, and a means for converging and organizing data received by the wireless communication units.
[0024] Further, the channel addition means in the intensive control unit includes a processing of selecting one wireless communication unit from among the wireless communication units which do not start to operate, a processing of making an operation start request to the wireless communication unit, a processing of notifying management information including a channel number and transmission power information operated by the wireless communication unit to the wireless communication unit, and a processing of receiving an operation preparation completed notification from the wireless communication unit.
[0025] Further, the means for switching operating channels in the intensive control unit includes a processing of determining a channel after being switched based on a list of white space channels, and a processing of instructing the wireless communication units to transmit a switch request message designating a channel after being switched, wherein the wireless communication unit includes a processing of broadcast- or unicast-transmitting to the plurality of or single terminal station, and a processing of notifying a channel switch completed notification to the intensive control unit.
[0026] The means for stopping operating channels in the intensive control unit includes a processing of determining whether to stop operating channels based on a list of white space channels, and a processing of instructing the wireless communication unit to transmit a stop request message, wherein the wireless communication unit includes a processing of broadcast- or unicast-transmitting to the plurality of or single terminal station, and a processing of notifying a stop completed notification to the intensive control unit.
[0027] The stop request transmits a stop request message or a channel after being switched in the channel switch request message as NULL.
[0028] The means for converging and organizing data in the intensive control unit includes a processing of selecting one item of normally-received data from among items of data received by the wireless communication units in a robust mode, and arranging an order of data, and a processing of arranging an order of data received by the wireless communication units in a high-speed mode.
[0029] The intensive control unit in the terminal station includes:
[0030] a channel addition means for making an operation start instruction to the wireless communication units in the terminal station, a means for switching operating channels in the wireless communication units, and a means for stopping operating channels in the wireless communication units; and
[0031] a means for performing a transmission data allocation processing and making a data transmission instruction to the wireless communication units, and a means for converging and organizing data received by the wireless communication units.
[0032] The channel addition means for making an operation start instruction to the intensive control unit includes a processing of selecting one wireless communication unit from among the wireless communication units, a processing of making a base station search instruction to the wireless communication unit, a processing of receiving a base station detection notification when the wireless communication unit finds a base station, a processing of determining whether the base station is the same as a base station connected to other wireless communication unit in operation, a processing of making a connection processing continuation instruction to the wireless unit when the determination processing is true, and receiving a synchronization completed notification in the wireless communication unit, a processing of registering the start of connection in a new channel in the base station, and a processing of transmitting a base station mismatch notification to the wireless communication unit when the base station match determination processing is false, and continuously searching a base station.
[0033] The means for switching operating channels in the intensive control unit includes a processing of receiving a channel switch request reception notification from the base station in the wireless communication unit, a processing of permitting the wireless communication unit to switch a channel and making a switch instruction, and a processing of receiving a channel switch completed notification in the wireless communication unit.
[0034] The means for stopping operation in the intensive control unit includes a processing of receiving an operation stop request reception notification from the base station in the wireless communication unit, a processing of permitting the wireless communication unit to stop operation and making a stop instruction, and a processing of receiving an operation stop completed notification in the wireless communication unit.
[0035] The means for converging and organizing data in the intensive control unit includes a processing of selecting one item of normally-received data from among items of data received by the wireless communication units, and arranging an order of data in a robust mode, and a processing of arranging an order of data received by the wireless communication units in a high-speed mode.
Advantageous Effects of Invention
[0036] According to the present invention, it is possible to enable a plurality of frequency channels to be dynamically operated and to realize high-speed and robust communication without any interference on a primary system in a multi-channel wireless communication system using a white space.
BRIEF DESCRIPTION OF DRAWINGS
[0037] FIG. 1 is a configuration diagram of a multi-channel wireless communication system according to a conventional form and one embodiment of the present invention.
[0038] FIG. 2 is a flowchart of basic operation processings in the multi-channel wireless communication system according to a conventional form (802.22 system) and the embodiment of the present invention.
[0039] FIG. 3 is a structural diagram of a wireless frame used in the multi-channel wireless communication system according to a conventional form and the embodiment of the present invention.
[0040] FIG. 4 is a schematic diagram illustrating communication between BS 2 and CPE 7 in a multi-channel wireless communication system according to Example 1.
[0041] FIG. 5 is a format of MAC PDU used in the multi-channel wireless communication system according to the first to fourth examples.
[0042] FIG. 6 is a flowchart of a channel allocation operation by CAM 41 in BS 2 according to Example 1.
[0043] FIG. 7 is a flowchart of a channel allocation operation by CAM 81 in CPE 7 according to Example 1.
[0044] FIG. 8 is a flowchart of a channel addition processing between BS 2 and CPE 7 according to Example 1.
[0045] FIG. 9 is a flowchart of a channel switch processing between BS 2 and CPE 7 according to Example 1.
[0046] FIG. 10 is a flowchart of a channel stop processing between BS 2 and CPE 7 according to Example 1.
[0047] FIG. 11 is a functional block diagram of BS 120 in the multi-channel wireless communication system according to Example 2.
[0048] FIG. 12 is a functional block diagram of CPE 170 according to Example 2.
[0049] FIG. 13 is a flowchart of an initialization processing in BS 120 according to Example 2.
[0050] FIG. 14 is a flowchart of an initialization processing in CPE 170 according to Example 2.
[0051] FIG. 15 is a flowchart of an operating channel discovery processing in BS 220 according to Example 3.
[0052] FIG. 16 is a flowchart of messages in channel negotiation in step S 54 according to Example 3.
[0053] FIG. 17 is a flowchart of a channel addition processing between BS 2 and CPE 7 according to the fourth example.
[0054] FIG. 18 is another flowchart of the channel addition processing between BS 2 and CPE 7 according to the fourth example.
DESCRIPTION OF EMBODIMENTS
[0055] Embodiments according to the present invention will be described below with reference to the drawings.
[0056] The same reference numerals are denoted to the same parts as those in other diagrams in each diagram referred to in the following description.
Example 1
[0057] FIG. 1 illustrates an exemplary entire structure of a multi-channel wireless communication system according to Example 1. The multi-channel wireless communication system is assumed to be applied (revised) to the 802.22, and has the same basic structure as ever. However, BS 2 and CPE 7 a , 7 b have the different structures from conventional ones, such as simultaneous transmission/reception in a plurality of channels. CPE 7 a and 7 b are collectively called CPE 7 .
[0058] FIG. 4 is a schematic diagram illustrating communication between BS 2 and CPE 7 in the multi-channel wireless communication system according to Example 1. BS 2 has a plurality of wireless communication units (BS-CHU) 13 a , 13 b , and a channel unit control manager (CHU-M) 14 for controlling the BS-CHUs. Inter-unit I/F 16 and 15 are provided between BS-CHU 13 and CHU-M 14 in order to connect them. CHU-M 14 also includes an Internet connection I/F 17 for connecting to the Internet (WAN).
[0059] BS-CHU 13 has a capability of transmitting and receiving wireless signals in one frequency channel with a predetermined bandwidth (of 5 MHz, for example) similar to the conventional 802.22-2011. A channel frequency used by each CHU is desirably variable (programmable). Since a frequency in a white space is wide-ranging, however, the band may be divided such that each CHU can vary a frequency channel in one divided band range. Each CHU 13 operates in synchronization with a timing of a physical layer (superframe, frame, TDD).
[0060] CHU-M 14 manages allocation (distribution) of downstream data (data plane) from the Internet to CHU, and generates MAP information. It further buffers upstream data (data plane) from CPE, and makes order organization or selection. CHU-M 14 has a channel allocation manager (BS-CAM) 41 for allocating operating channels to individual BS-CHUs 13 , and a CPE management unit 42 for holding information on CPE connected to BS 2 and managing states of CPE (not illustrated).
[0061] The inter-unit I/F 15 and 16 are logical, and do not necessarily need to be with hardware.
[0062] The structure of CPE 7 is the same as BS 2 except its details, and has a plurality of CPE-CHUs 71 .
[0063] CPE-CHU 71 requires lower transmission power than BS-CHU 13 in BS, and can be easily used as hardware for all bands.
[0064] CHU-M 72 has a channel allocation manager (CPE-CAM) 81 (not illustrated) for allocating operating channels to individual CPE-CHUs 71 .
[0065] BS-CHU 13 or CPE-CHU 71 may be an entity on software capable of being handled as a unit in which a wireless processing is performed for one channel in the MAC layer processing. BS-CHU 13 or CPE-CHU 71 has specific CHUID (CHU-IDentification), respectively.
[0066] In Example 1, in terms of a pair of BS and CPE in a cell, CHUs are assumed to be connected in one-to-one basis. That is, one CHU is not connected to a plurality of CHUs at the same time. The number of channels used for communication between BS and CPE at the same time is limited within the smaller number of CHUs in either of BS or CPE.
[0067] The multi-channel data transmission systems include a robust mode of transmitting and receiving the same data in a plurality of (all of) pairs of connected CHUs, a dispersion mode of dividing and transmitting and receiving data to any pair, and an adaptive mode of adaptively selecting one of the two modes.
[0068] FIG. 5 illustrates a MAC PDU format used for transmitting multi-channel data in the present example. MAC PDU (Protocol Data Unit) is a unit of data configuring each burst indicated in FIG. 3 . In other words, burst is configured of one or more MAC PDUs, which are arranged on sub-channels and symbols of OFDM. MAC PDU in the 802.22 is basically configured of MAC header with a predetermined length (32 bits for Generic MAC header), MAC payload with a variable length subsequent thereto, and CRC (Cyclic Redundancy Check) code with 32 bits subsequent thereto. A sub-header may be provided between MAC header and MAC payload, and CRC is not essential if it can use other error protection (such as check vector).
[0069] In the present example, as illustrated in FIG. 5 , MAC PDU communicated during multi-channel operation is always provided with Aggregation Header at a position corresponding to a sub-header. Aggregation Header is used to manage bundled data sequences and aggregation types, and is notified to the reception side in a format defined as in Table 1.
[0000]
TABLE 1
Syntax
Size
Notes
Aggregation_Header_Format( ) {
Aggregation ID
16 bits
Indicates the sequence management ID of the
transmitted data during multi-channel
operation. The value of Aggregation ID is
from 0 to 8191. The Aggregation ID shall be
incremented by one after each transmission
and shall be reset to 0 after the maximum
value (8191).
Aggregation Type
8 bits
This field specifies the aggregation type of
the transmission.
0x00: No aggregation.
0x01: Diversity mode.
0x02: Bulk transmission mode.
0x03-0xFF: Reserved.
}
[0070] Herein, Diversity mode (0x01) of Aggregation Type corresponds to the robust mode, and Bulk transmission mode (0x02) is directed to make a plurality of channels seem one wideband transmission path and corresponds to the dispersion mode. Aggregation ID is incremented by one each time Aggregation header is newly generated, and returns to 0 next to the upper limit of 8191 (the higher 3 bits in 16 bits are reserved for the future). Aggregation ID in Diversity mode has the same value for PDUs which are redundantly transmitted in a plurality of channels from the same source. Aggregation Header is basically given to all PDUs transmitted from BS or CPE during multi-channel operation, which may be achieved if at least one transmission is performed in one PHY frame. For example, Aggregation header may be given to only PDU at the header of each burst, and is not necessary for MAC PDU of burst transmitted to the reception side which does not need to recognize or cannot recognize (conventional 802.22 system) the multi-channel operation.
[0071] FIG. 6 is a flowchart illustrating a channel allocation operation by BS-CAM 41 according to Example 1. Three basic functions including channel addition processing (CAM-ADD), channel stop processing (CAM-STP) and channel switch processing (CAM-SWH) are newly defined in order to allocate a plurality of channels. The three functions are achieved by exchanging or unilaterally transmitting predetermined messages or the like between BS and CPE as described later. BS-CAM 41 mainly determines an operating channel, and subsequently performs any of the three functions.
[0072] In BS 2 , a timing when an operating channel is determined (or a channel is added, stopped and switched) by BS-CAM 41 is scheduled such that a specific channel is available when a change in WSCH is found due to reception of DB access, sensing or CPE sensing result and only in a predefined period of time. Even at the timing, there may be made a determination that BS-CAM 41 does not change an operating channel (that is, does not add or stop or switch). For example, even if a backup or candidate channel capable of being allocated for multi-channel operation is left, when no CPE having a multi-channel operation capability is present, an operating channel does not need to be further added. The multi-channel operation capability of CPE is notified by CPE via a CBC-REQ message (described later).
[0073] FIG. 7 is a flowchart illustrating a channel allocation operation by CPE-CAM 81 according to Example 1. CPE-CAM 81 has the three functions including the channel addition processing, the channel stop processing and the channel switch processing similar to BS-CAM 41 . However, most of them are performed according to an instruction from BS-CAM 41 .
[0074] That is, the channel switch processing is performed when a switch request (CAM-SWH) as a control message (management message) is received from BS.
[0075] The channel stop processing is performed when a stop request (CAM-STP) as a control message is received, when a primary system is sensed by self-sensing, or when a channel is determined to be stopped by the scheduling.
[0076] The channel addition processing may be performed when it is determined that the operation can be started in a channel by the scheduling, when a BS lost message is received from CHU 71 (or CHU non-connected with BS is present), or when aggregation information (CAM-AIF) as a control message is received (not illustrated).
[0077] FIG. 8 is a flowchart of the channel addition processing performed between BS 2 and CPE 7 according to Example 1.
[0078] In step S 1 , BS-CAM 41 in BS 2 selects CHU to be subject to the channel addition processing. The CHU, which is not currently used (not allocated) and whose hardware accepts the frequency of a channel to be allocated, is selected from BS-CHUs 13 in BS 2 . Part of step S 1 may be included in the operating channel determination in FIG. 6 .
[0079] In step S 2 , BS-CAM 41 transmits a CHU operation start request to the selected BS-CHU 13 . The CHU operation start request may include various parameters on physical layer such as channel frequency (center frequency) and its offset, or part of MIB information (such as software version information).
[0080] In step S 3 , BS-CHU 13 transmits a start request reception response to BS-CAM 41 . The start request reception response may include CHU-specific MIB information required for CHU-M (such as serial number or Device ID of CHU). When the start request cannot be received due to mismatched version, an error is responded.
[0081] In step S 4 , BS-CAM 41 transmits a management information notification to BS-CHU 13 . The management information notification may mainly include MIB information maintained in BS-CAM 41 and required for BS-CHU 13 , and may also include ID (carrier index associated with a channel frequency) for specifying connection between BS and CPE. If BS-CHU 13 has part of the MAC layer function, MIB information used for MAC, such as Station ID, or MAC address of BS 2 , is required.
[0082] When three-directional communication in steps S 2 to S 4 is successful, in step S 5 , BS-CHU 13 performs a processing of storing the management information received in step S 4 . Part of the stored information (MIB information) is immediately reflected at each part of CHU, or is initialized for its transition state.
[0083] In step S 6 , BS-CHU 13 performs a frequency setting processing. Herein, a center frequency and its offset received in step S 2 or S 4 are reflected on a local oscillator in BS-CHU 13 .
[0084] In step S 7 , BS-CHU 13 performs a CHU synchronization processing. The processing is directed for network synchronization for synchronizing timings of superframe, frame and TDD between a plurality of BSs in the wireless communication system, and basically synchronizes superframes at the start of each minute of UTC time acquired from GPS or the like. Consequently, CHUs in operation are synchronized with each other.
[0085] When the processings in steps S 5 to S 7 are successfully performed, in step S 8 , BS-CHU 13 transmits an operation preparation completed notification to BS-CAM 41 . If the processings fail halfway, a response indicating the error is transmitted.
[0086] Subsequent to step S 8 , in step S 9 , a wireless frame including SCH is periodically transmitted. SCH may include a newly-defined CHID (Channel ID) with about 2 bits including BS_ID as MAC address of BS 2 and indicating from which BS-CHU 13 it is transmitted.
[0087] On the other hand, on the CPE 7 side, the following processings are performed irrespective of the progress of steps S 1 to S 8 .
[0088] At first, in step S 11 , CPE-CAM 81 in CPE 7 selects CHU to be subjected to the channel addition processing. In many cases, the processing is started when CPE-CHU 71 in the BS lost state is caused in CPE 7 , and thus the CPE-CHU 71 is selected.
[0089] In step S 12 , CPE-CAM 81 transmits a BS search instruction to the selected BS-CHU 13 . The BS search instruction may be made by designated one or more channels, or may be directed to search all the frequencies for CHU. When a channel being used by BS 2 and not connected is determined by an extended DCD message or the like or may be estimated based on a backup channel, the channel may be designated. A channel already used by other CPE-CHU 71 is not searched for preventing overlap. Further, a channel which is determined as being used by other BS based on previous search or the like is searched at the lowest priority.
[0090] In step S 13 , CPE-CHU 71 , upon receiving the BS search instruction, tries to detect a wireless signal (preamble and SCH) from BS at a frequency to be searched. When it can detect a wireless signal at a predetermined signal level or more, in step S 14 , it transmits a BS detection notification to CPE-CAM 81 . The notification includes BS-ID obtained by decoding SCH.
[0091] In step S 15 , CPE-CAM 81 determines whether other CHU in operation (connected with any BS) is present. The absence of CHU in operation does not correspond to channel addition (multi-channel operation), and thus the processing proceeds to a synchronization processing (step S 18 described later) similar to the conventional IEEE 802.22.
[0092] In step S 16 , when CHU in operation is present, a determination is made as to whether a connection destination of the CHU is the same as BS indicated in step S 13 .
[0093] When not matched, in step S 17 , CPE-CAM 81 transmits a BS mismatch notification as a response for the BS detection notification to CPE-CHU 71 . Thereby, CPE-CHU 71 restarts to search the remaining frequencies to be searched. Alternatively, the processing returns to step S 12 , where CPE-CAM 81 transmits a new BS search instruction of designating another frequency to be searched to CPE-CHU 71 .
[0094] When matched in step S 16 , in step S 18 , a continuation notification is transmitted as a response for the BS detection notification as needed.
[0095] In step S 19 , CPE-CHU 71 , upon receiving the continuation notification, continues the synchronization processing at a frequency where SCH is detected. Step S 19 includes a processing of receiving a UCD (Upstream Channel Descriptor) message and acquiring upstream parameters or a ranging processing of adjusting a TDD timing in addition to a narrow synchronization processing of detecting and decoding FCH or DS-MAP and acquiring downstream parameters.
[0096] Then, in step S 20 , CPE-CHU 71 transmits a synchronization completed notification as a response for the continuation notification to CPE-CAM 81 . Thereby, CPE-CAM 81 can recognize that a plurality of CHUs are provided for BS 2 (become multi-channel), and in step S 21 , transmits a notification for requesting to register that CPE 7 successfully enters multi-channel (aggregation) to BS 2 . The registration request includes a number (such as carrier index or CHID) capable of specifying each channel configuring the multi-channel, and can further include a designated communication mode (any of the robust, dispersion and adaptive modes). When not satisfied with the reception quality, CPE can designate the robust mode by which a diversity effect can be expected, and when not satisfied with the communication speed, it can designate the dispersion mode.
[0097] In step S 22 , the CPE management unit 42 in BS 2 , upon normally receiving the registration request, returns a registration completed notification. Thereby, the channel addition processing is completed, and data communication is then made between BS 2 and CPE 7 in the designated mode.
[0098] CPE 13 is managed or in a state where MIB information is exchangeable by SNMP before being in multi-channel, but if MIB information or necessary setting file specific to the added channel is present, after acquisition of the same, the completed registration for the added channel may be explicitly notified in a management message.
[0099] FIG. 9 is a flowchart of the channel switch processing performed between BS 2 and CPE 7 according to Example 1.
[0100] In step S 31 , BS-CAM 41 in BS 2 transmits a CH switch request to BS-CHU 13 to be subject to channel switching. The BS-CHU 13 has to accept a channel frequency in the switched destination.
[0101] In step S 32 , BS-CHU 13 , upon normally receiving the CH switch request, sets a channel switch timer. BS-CHU 13 always counts a frame number, and setting the timer indicates determining a future frame number to be changed.
[0102] In step S 33 , BS-CHU 13 transmits a reception response for the CH switch request to CAM. Further, the CH switch request is downstream transmitted. The CH switch request is a management message, and is different from the CH switch request in step S 31 which is just a signal in the device. The management message has a data structure starting with a predetermined Type field, and is sent to all of CPE in broadcast connection. Each CPE has to receive and interpret all the management messages in principle.
[0103] The CH switch request according to Example 1 is newly defined by adding a field or information element indicating a channel number of a switch destination as in a DREG-CMD message to a CHS-REQ message with Management Message Type=26 defined in the IEEE 802.22-2011, and has information for specifying a (incumbent) channel to be changed, or a Switch Count field indicating the number of remaining frames until switching. The information element indicating a channel number may be a channel number (carrier index) itself, or may indicate what number channel in a list of backup and candidate channels included in a DCD (Downstream Channel Descriptor) message as another management message. The information for specifying a channel after being switched may be also a channel number itself, or ID (such as CHID) for identifying connection (association) between CHU on the BS side and CHU on the CPE side, and may be replaced with SID (Station ID), CID (Connection ID), or the like.
[0104] The DCD Channel information elements may additionally include a field or information element similar to the CH switch request. Further, when the management messages are classified per channel by use of only the dispersion mode, the information for specifying a channel after being switched is not necessarily needed.
[0105] In step S 34 , CPE-CHU 71 in CPE 7 , upon normally receiving the CH switch, request sets a CH switch timer.
[0106] In step S 35 , CPE-CHU 71 notifies CPE-CAM 81 of reception of the CH switch request.
[0107] In step S 36 , CPE-CAM 81 , upon grasping that the channel is to be changed, performs switch permission (instruction) if there is no problem is in the channel to be switched.
[0108] In step S 37 , CPE-CHU 71 , upon receiving the switch permission upstream, transmits a reception response for the CH switch request in step S 33 to BS 2 . The reception response is also a management message, and newly defines and employs a similar message to a CHU-REP message with Management Message Type=27 according to Example 1.
[0109] In step S 38 , when the CH switch timer reaches a set frame number and ignites, BS-CHU 13 performs channel switching. That is, the operational parameters are changed within a frame border (RTG) time, and a frequency of the local oscillator is synchronized with a channel of the change destination. In most cases, since the channel switching is performed when an incumbent channel has to be released, even when a reception response in S 37 cannot be received from any CPE, the channel switching is absolutely performed.
[0110] At the same time with step S 38 , in step S 39 , the channel switching is performed also in CPE 7 when the timer elapses.
[0111] Then, in step S 40 , BS-CHU 13 in BS 2 transmits a switch completed notification to BS-CAM 41 . This indicates that the switching is completed (the frequency of the local oscillator is locked, or the like) in the physical layer.
[0112] Next, in step S 41 , BS-CHU 13 transmits SCH, DS-MAP, DCD, and UCD.
[0113] Next, in step S 42 , when receiving a frame including SCH and correctly receiving the SCH or the like, CPE-CHU 71 in CPE 7 transmits a switch completed notification to CPE-CAM 81 . The switch completed notification indicates that the switching is temporarily completed in the MAC layer.
[0114] At last, in step S 43 , CPE-CHU 71 transmits a switch completed notification (CHS-CPLT) to BS 2 . The switch completed notification is a management message, and is newly defined similar to a CHS-RSP message according to Example 1, and the CPE management unit 42 in BS 2 , upon receiving the same, updates its holding information on CPE.
[0115] In the channel switch processing, the timer may be managed in CAM. For example, the CH switch request in step S 33 may be received by CPE-CAM 81 , and CPE-CHU 71 may be instructed to set the timer.
[0116] FIG. 10 is a flowchart of the channel stop processing performed between BS 2 and CPE 7 according to Example 1.
[0117] In step S 51 , BS-CAM 41 in BS 2 transmits a CHU stop request to BS-CHU 13 to be subject to channel stop.
[0118] Then, in step S 52 , BS-CHU 13 , upon receiving the CH stop, request sets an operation stop timer. Setting the timer indicates determining a future frame number to be stopped.
[0119] Then, in step S 53 , BS-CHU 13 transmits a reception response for the CH stop request to BS-CAM 41 . Further, it downstream transmits an operation stop request. The CH stop request is a management message, and in Example 1, a new message (CHOS-REQ) is defined in which a Switch Count field or Next Channel Number field and information for specifying a channel to be stopped are added to a DREG-CMD (De/Re-Register Command) message with Management Message Type=21 or CHS-REQ message. DREG-CMD intends to cause all CPE to immediately stop transmitting at incumbent operating channels for protecting the primary system, and cannot be transmitted from any CHU until new DREG-CMD for permitting transmission at the frequency is issued. A CHS-REQ message with Management Message Type=28 intends to provide a temporary quiet period (QP). To the contrary, the operation stop request in the present example intends to separate (release) only specific CHU from CAM, and does not perform reception in an operating channel. The CH stop request may be realized by designating Null as a channel number of the switch destination in the CH switch request in the management message used in the channel switch processing in FIG. 9 .
[0120] Then, in step S 54 , CPE-CHU 71 after receiving the operation stop request determines whether the request is directed for itself based on the information for specifying a channel to be stopped indicated by the request, and when the request is directed for it, CPE-CHU 71 sets an operation stop timer similarly as in step S 52 .
[0121] In step S 55 , CPE-CHU 71 notifies CPE-CAM 81 of reception of the operation stop request.
[0122] In step S 56 , CPE-CAM 81 , upon grasping that the channel operation is to be stopped, makes stop permission and request.
[0123] In step S 57 , CPE-CHU 71 receiving the stop permission and request upstream transmits an operation stop reception response for the operation stop request in step S 53 to BS 2 . The reception response is also a management message, and a similar message to a CHS-RSP message or the like is newly defined for use in Example 1.
[0124] In step S 58 , when the operation stop timer reaches a set frame number and ignites, CPE-CHU 71 stops operation. That is, transmission and reception are completely stopped and the operating channel is also forgotten.
[0125] At the same time with step S 58 , in step S 59 , the operation is stopped also in BS-CHU 13 in BS 2 when the timer elapses.
[0126] At last, in step S 59 , CPE-CHU 71 and BS-CHU 13 , for which operation is completely stopped, transmit an operation completed notification to CPE-CAM 81 and the CPE management unit 42 .
[0127] The operation-stopped CHU may be then subject to the CHU addition processing. The timer may be managed in CAM in the channel stop processing.
[0128] As described above, in the present example, the CH switch request is transmitted (only) in the switch source channel, and the operation stop request is transmitted (only) in the channel to be stopped. That is, a management message is not forced to be received in a channel not to be switched or stopped for switching or stopping, or a master-slave relationship is not provided for the channels. Thereby, as described in Patent Literature 1, unlike when a management message is transmitted and received only in a specific control channel (main carrier wave) defined by BS, a channel may be accurately switched or stopped for CPE in the environment in which cannot receive such a control channel.
Example 2
[0129] FIG. 11 is a functional block diagram of BS 120 in a multi-channel wireless communication system according to Example 2. Additionally, FIG. 12 is a functional block diagram of CPE 170 in the multi-channel wireless communication system according to Example 2. In the present example, detailed mounting not described in Example 1 will be described, and unless otherwise noted, the structure and functions according to Example 1 will be employed. FIG. 11 and FIG. 12 express hardware in more detail than FIG. 4 .
[0130] As illustrated in FIG. 11 , BS 120 includes a plurality of BS-CHUs 130 a , 130 b (collectively denoted as 130 ), a CHU-M 124 , and a sensing unit 125 .
[0131] CHU-M 124 includes the channel allocation manager (CAM) 41 for allocating operating channels to individual BS-CHUs 130 , the CPE management unit 42 for holding information on CPE 170 connected to BS 2 and managing states of CPE, a management information processing unit (MIB) 43 , a DB access control unit 44 , a communication data control unit 45 , and a sensing control unit 46 .
[0132] The channel allocation manager (BS-CAM) 41 corresponding to BS-CAM described in Example 1 is directed for managing channels, and performs the processings of adding, stopping and switching channels while communicating predetermined management messages with CPE, thereby realizing multi-channel MAC. BS-CAM 41 grasps a frequency acceptance situation, use situation, transition state and the like of each BS-CHU 130 in at least its own BS 120 , and performs channel descriptor management such as management for allocating frequencies accepted by BS-CHU and in a WSCH list, or generation of SCH and DCD. BS-CAM 41 has a function on a higher layer (Network Control and Management System), and has effects on operating channel determination.
[0133] The CPE management unit 42 maintains the latest information on all CPE 170 connected to BS 120 acquired in a management message or the like in the table, and responds to inquiries from others. The table holds therein, per CPE, ID for specifying CPE, any of Device ID, serial number or station ID, information specific to each CPE such as MAC address of CPE 170 (CHU-M in CPE), the number of CHUs, ID (CHUID) or channel number per CHU, and state. The state includes information such as discrimination among stopped, synchronized (connected), and managed node, multi-channel or not, and mode in multi-channel. Information on CHU in each CPE is limited to a graspable range, and does not need to include CHU connected to other base station, for example.
[0134] When BS operates in multi-channel, the CPE management unit 42 controls (channel scheduling) to divide or duplicate data into channels per CPE.
[0135] The information management processing unit 43 maintains the latest MIB information by use of SNMP (Simple Network Management Protocol) or the like thereby to respond to inquiries from others, or directly gives it from the hardware. BS or CPE for which updated MIB is kept by SNMP is called managed node.
[0136] The DB access control unit 44 uses PAWS (Protocol to Access White Space database) or the like to find the DB server 6 over the Internet, to access it to acquire a WSCH list, or to notify its occupied channel or a channel detecting a primary system to the DB server 6 . The information is reflected on MIB in the information management processing unit 43 as needed.
[0137] The communication data control unit 45 controls and buffers queue, transmission order or flow depending on a class of data (data plane), and MAP-allocates the same together with management plane or cognitive plane's communication data (such as management message). Information on mapping determined by MAP allocation in a management message such as DS-MAP or US-MAP is output to each BS-CHU 130 together with corresponding communication data. MAP allocation of upstream subframes is performed based on band request or reception state from each CPE. During multi-channel operation, the allocation processing is performed across a plurality of channels. That is, a determination is made based on a predetermined scheduling rule and a multi-channel communication mode as to on which burst in which channel data of each queue or each CPE is placed. The upstream data received from a plurality of BS-CHUs 130 may be converged or organized (discarding redundant packets) in the communication data control unit 45 , but may be processed in a convergence sublayer higher in the MAC layer, or a much higher layer.
[0138] The sensing control unit 46 functions as SM (Spectrum manager) and its higher layer, and controls the sensing unit 125 or the like based on spectrum sensing automaton (SSA) to perform sensing (Out-of-band sensing). Information (such as UCS) acquired from BS-CHU 130 is mainly used for In-band sensing. The list of channels holding classified available channels is updated based on the sensing information. The available channels in the list are classified into “Disallowed”, “Operating”, “Backup”, “Candidate”, “Protected”, and “Unclassified.”
[0139] The sensing unit 125 includes a signal reception unit and a signal analysis unit, and provides the sensing control unit 46 with the spectrum sensing function as a physical layer.
[0140] Each BS-CHU 130 according to the present example includes a MAC processing unit 131 , a PHY processing unit 132 , a transmission/reception unit 133 , a management information processing unit 134 , an inter-unit I/F 135 , and an antenna 136 . Each BS-CHU 130 includes specific CHUID.
[0141] The MAC processing unit 131 performs a MAC processing at a lower level by one channel. The MAC processing includes a processing according to an instruction from CHU-M or a security layer processing, such as a processing of making MAC PDU from CHU-M or communication data of burst unit into MAC frames based on information indicating MAP allocation acquired from the communication data control unit 45 or its reverse de-frame processing.
[0142] The PHY processing unit 132 is configured of a digital signal processing device, receives MAC frames from the MAC processing unit 131 to perform channel encoding, burst modulation, physical framing, OFDM modulation and D/A conversion thereon to output to the transmission/reception unit, and performs the processings reverse to them. The PHY processing unit 132 performs MIMO or adaptive antenna processing as needed.
[0143] The transmission/reception unit 133 is configured of a high frequency device or the like, and performs conversion between wireless frequency and intermediate frequency, power amplification of transmission signal, control of transmission power, amplification of reception signal, measurement of reception power, control of reception gain, and the like.
[0144] The processings for transmission in the MAC processing unit 131 to the transmission/reception unit 133 are performed on receiving mapping information from the communication data control unit 45 , which may be assumed as transmission instruction.
[0145] The management information processing unit 134 gives MIB information or the like to the MAC processing unit 131 , the PHY processing unit 132 or the transmission/reception unit 133 , or acquires the same therefrom, and manages MIB in association with the management information processing unit 43 . MIB information to be held by the management information processing unit 134 includes a table indicating a correspondence between a channel number (carrier index) and an actual carrier frequency. The management information processing unit 134 holds information or the like required to accurately manage transmission power or antenna directivity in addition to the information defined for MIB irrespective of a channel unit or frequency, and controls the PHY processing unit 132 . For example, properties specific to each channel unit (such as available frequency range, and values of gain, delay and the like at each channel frequency in the range. Properties of power supply line connecting channel unit and antenna are included.) are previously held, and compensation or notification to the MAC layer is performed based on the information. Information on a channel in which the capability of the transmission/reception unit is inadequate and use of it is posteriori prohibited or transmission power is limited is held and is notified to the MAC layer.
[0146] The GPS unit provides geographic location information on BS 2 required to acquire a WSCH list from the DB server 6 , and is operable as a high-accuracy clock for synchronizing a plurality of BS or a high-accuracy frequency source.
[0147] The antenna 135 is configured to be provided per CHU in the present example, but not limited thereto, the antenna may be commonly used with a CIB (Constant Impedance Band-pass) common device or butler matrix.
[0148] The structure of CPE 170 illustrated in FIG. 12 is schematically the same as BS 120 except that the CPE management unit is not provided.
[0149] The initialization processings in BS 120 and CPE 170 according to the present example will be illustrated in FIG. 13 and FIG. 14 , respectively.
[0150] As illustrated in FIG. 13 , the initialization processing in BS 120 according to the present example is different from the initialization processing in the 802.22 in that a step (S 69 ) of presenting a list of available TV channels to higher layers, and a step (S 70 ) of starting a multi-channel operation after the presentation are newly provided after the primary system detection processing or at the end of the initialization processing.
[0151] At first, in step S 61 , BS 120 is installed by an expert.
[0152] Then, in step S 62 , antenna information including an antenna gain table is acquired. The antenna gain table is stored in MIB in the management information processing unit 41 , but if not, is acquired from an antenna (antenna unit) via serial communication.
[0153] Then, in step S 63 , geographic location (longitude and latitude of WGS 84 geodetic system) of BS 120 is determined.
[0154] Then, in step S 64 , a determination is made as to whether WSDB is present (or accessible) in a service area of BS 120 . When it is determined that WSDB is not present, in step S 65 , the spectrum manager (the sensing control unit 46 ) in BS 120 considers all the channels initially available.
[0155] When it is determined that WSDB is present, in step S 66 , a list of initially available channels (WSCH list) is received from WSDB based on primitive such as M-DB-AVAILABLE-REQUEST.
[0156] Then, in step S 67 , the operator of BS 120 makes part of the initially available channels unavailable as needed.
[0157] Then, in step S 68 , an existing system is detected and network synchronization with other neighboring BS is made in all the available channels.
[0158] Then, in step S 69 , the spectrum manager in BS 120 presents a list of available channels to a higher layer (Network Control and Management System) by use of M-AVAIL-TV-CH-REPORT primitive in order to select one or more operating channels. A format of M-AVAIL-TV-CH-REPORT.request primitive is indicated in Table 2.
[0000]
TABLE 2
Valid
Name
Type
Range
Description
For (i=1; i≦ Number of
List of available
List of available channels and
Channels Available; i++) {
channels and
corresponding Maximum Allowed
Channel_Number
their Maximum
EIRP.
Maximum Allowed EIRP
Allowed EIRP
}
Mode
The expected response from the
higher layers
0 = Test
1 = Request for disallowed
channel classification
2 = Request for selection of
operating channel
3 = Request for selection of
operating channels in multi-
channel operation mode
[0159] The M-AVAIL-TV-CH-REPORT.request primitive is used for requesting to designate a disallowed channel or to select an operating channel, has a mode parameter extended as compared with the 802.22, and designates mode=2 on activation for single carrier operation and mode=3 on activation for multicarrier operation. Thereafter, one or more operating channels selected from a higher layer by use of M-OPERATING-TV-CH or M-OPERATING-TV-CHS primitive are notified to the spectrum manager and are reflected on MIB. A format of M-OPERATING-TV-CHS.indication primitive according to the present example is indicated in Table 3.
[0000]
TABLE 3
Valid
Name
Type
Range
Description
For (i=1; i≦ Number
The selected
The selected
of ChannelsinMulti-
operating
operating
channel Operation;
channels in
channels in
i++) {
multi-channel
multi-channel
Channel_Number
operation mode
operation mode
}
[0160] The M-OPERATING-TV-CHS.indication primitive is used by a higher layer in order to respond a plurality of operating channels selected from the list of available channels for each request from the spectrum manager in the multi-channel operation mode. The operating channels are indicated by a number (Channel-Number) indicating what number channel from the header in the list of available channels presented in M-AVAIL-TV-CH-REPORT.request.
[0161] The higher layer can arbitrarily select an operating channel from the list of available channels, and can actually use it in hardware of each CHU provided in BS based on a spectrum sensing result, and a channel with a least possible interference is desirably selected. When the multicarrier operation is denied by the higher layer, the spectrum manager may issue M-AVAIL-TV-CH-REPORT primitive with mode=2 again, and may receive one operating channel.
[0162] At last, in step S 70 , the single carrier operation or multicarrier operation is started in the selected operating channel.
[0163] As illustrated in FIG. 14 , the initialization processing in CPE 170 is different from the initialization processing in the conventional 802.22 in that a step (S 75 ) of selecting a 802.22 service on installation or activation is newly provided after the physical layer acquires similar (compatible) 802.22 service advertising, reception signal level and sensing result or before GPS positional information is completely acquired.
[0164] At first, in step S 71 , CPE 170 performs self-test.
[0165] Then, in step S 72 , self-antenna gain information is acquired similarly as in step S 62 in BS.
[0166] Then, in step S 73 , a WRAN service by BS is sensed and synchronized. In this step, a sensing thread starts to detect an existing system (TV) in transmission.
[0167] Then, in step S 74 , the spectrum manager in CPE 170 presents a sensing result to a higher layer (application layer). Specifically, the spectrum sensing automaton (SSA) in the spectrum manager issues M-WRAN-SERVICE-REPORT primitive, and requests the application to select a plurality of channels from a list of available WRAN services. The M-WRAN-SERVICE-REPORT.request primitive includes a list containing available WRAN services, their frequency channels, and reception signal levels (RSSL).
[0168] Then, in step S 75 , when trying multicarrier operation, the application selects a plurality of WRAN services from available BSs based on the presented sensing result (presence of available BSs and existing systems specified in the area). That is, whether to employ multicarrier operation or single carrier operation is determined by the application. For example, multi-channel compatible services can be preferably selected or selected vice versa depending on the number of provided CHUs.
[0169] Then, M-WRAN-SERVICE-RESPONSE primitive including information on the selected channels is issued as a response for the M-WRAN-SERVICES-REPORT.request toward SSA. M-WRAN-SERVICES-RESPONSE.indication primitive according to the present example is newly defined with extended M-WRAN-SERVICE-RESPONS in responding one selected channel, and a format thereof is indicated in Table 4.
[0000]
TABLE 4
Valid
Name
Type
Range
Description
For (i=1; i≦ Number
The selected
The selected
of ChannelsinMulti-
operating
operating
channel Operation;
channels in
channels in
i++) {
multi-channel
multi-channel
Channel_Number
operation mode
operation mode
}
[0170] In the present example, the selected channels are indicated by channel numbers.
[0171] After receiving the selected channels, SSA more strictly performs sensing again in the selected channels and their adjacent channels, and detects whether a weak existing service is hidden behind the WRAN services in the selected channels.
[0172] Then, in step S 76 , valid geographic location data is collected by use of GPS. If data collection fails, CPE cannot continue initialization.
[0173] Then, in step S 77 , upstream and downstream parameters are acquired from the selected WRAN services.
[0174] Then, in step S 78 , if necessary, azimuth (radiation beam direction) of the antenna in CPE is directed toward BS or in a direction with less pre-interference or interfered. An adjusted azimuth angle (measured clockwise with true north at 0 degree) is reflected on MIB, and is notified to the BS side.
[0175] Then, in step S 79 , when one (channel N) of the selected channels and its adjacent channels pass sensing and successfully detect a timing when a ranging request is possible, CPE performs initial ranging with BS.
[0176] Then, in step S 80 , a determination is made as to whether one (channel N) of the selected channels and its adjacent channels meet the sensing criteria and successfully detect a timing when a ranging request is possible. If they are not successful within a predetermined time, CPE performs initialization from the beginning again.
[0177] When it is determined that they are successful, in step S 80 , CPE performs initial ranging with BS.
[0178] Then, in step S 81 , CPE transmits self basic capabilities to BS according to a CBC-REQ message. The CBC-REQ (CPE Basic Capability REQuest) message is a management message (described later) with Management Message Type=19 which is transmitted only on initialization of CPE in principle, and the basic capabilities include physical parameters supported by CPE, such as maximum EIRP transmitted from CPE, modulation system accepted by CPE, or whether a multi-channel operation capability is provided. The multi-channel operation capability is newly defined as information element called “Multi-channel operation supported” as indicated in Table 5.
[0000]
TABLE 5
Length
Element ID
(bytes)
Value
Scope
8
1
0x00: Multi-channel operation not
CBC-REQ,
supported.
CBC-RSP
0x01: Multi-channel operation
supported.
0x02-0xFF: Reserved.
[0179] Whether the multi-channel operation capability is actually exercised even if CPE transmits 0x01 depends on CPE. For example, it is possible that CPE-CHU in the BS lost state may not be subjected to the channel addition processing in S 11 in FIG. 7 in order to save power.
[0180] Then, in step S 82 , an AAA (Authentication, Authorization, and Accounting) service in a higher layer tries CPE authentication.
[0181] When authentication fails, in step S 83 , CPE records the authentication denial result and does not consider BS that denies the authentication for a while. Also on the BS side, temporary registration of CPE on successful ranging is erased.
[0182] When authentication is successfully made, in step S 84 , AAA performs key exchange between BS and CPE.
[0183] Then, in step S 85 , a REG-REQ/RSP message is exchanged thereby to register CPE. The REG-REQ message transmitted from CPE to BS includes information elements indicating the CPE capabilities such as character string of NMEA 0183 format as a measurement result of CPE's geographic location, or whether to support ARQ.
[0184] The spectrum manager in BS determines whether an NMEA character string is valid, and if valid, returns REG-RSP including CPE setting (such as IP version, or IP address used for preliminary management connection) corresponding to the CPE capabilities (step S 85 a ). If invalid, the initialization fails (step S 85 b ). Thereafter, CPE collates the CPE setting designated in REG-RSP with its capabilities, and when being able to perform the CPE setting, it is permitted to enter the network (step S 85 c ). Thereafter, when it is confirmed that MIB information can be exchanged between BS and CPE, registration is achieved.
[0185] Then, in step S 86 , BS transmits a DCD message including a channel set to CPE. The channel set is called when part or all of the channel lists managed by the spectrum manager is sent in DCD or the like. “Operating” described herein indicates operating also in a destination CPE, and does not include a channel which is being initialized. Therefore, the channel set transmitted to CPE is “Backup and Candidate channel list” with Element ID=10.
[0186] Then, in step S 87 , CPE establishes IP connection by use of a mechanism such as DHCP, and then in step S 101 , time and date of an inner clock in CPE is adjusted by use of a mechanism such as NTP.
[0187] Then, in step S 88 , CPE acquires a setting file including operational parameters from BS by use of TFTP (Trivial File Transfer Protocol).
[0188] Then, in step S 89 , BS transmits a DSA-REQ message to cause CPE to set up a previously-provided service flow.
[0189] At last, in step S 90 , a neighboring network found by trying to receive preamble, or SCH or CBP packets transmitted from other BS is reported to BS. The processings similar to S 75 and S 90 are performed as IDRP (incumbent detection recovery protocol) in cooperation with BS also after the operation is started, and is reflected on the channel set in the DCD message.
Example 3
[0190] A scheme for evenly sharing channels, which has not been described according to Examples 1 and 2, will be described according to the present example. The structure and functions according to Example 1 will be employed.
[0191] BS 220 according to Example 1 explicitly includes a self-co-existence function unit 47 . The self-co-existence function unit 47 additionally has a channel negotiation function in addition to co-existence by conventional frame contention or the like. Channel negotiation eliminates a situation in which BS which earlier starts operation occupies a plurality of channels and BS which is activated later cannot use any channel.
[0192] Four new messages including channel release request (CHN-REQ), channel release time notification (CHN-RSP), channel release time acknowledgement response (CHN-ACK) and channel release completion (CHN-CPLT) are defined in the MAC layer in order to realize the channel negotiation function.
[0193] FIG. 15 is a flowchart of an operating channel discovery (determination) processing by BS 220 according to Example 3.
[0194] The flow starts after the use situations of channels of (a plurality of) adjacent cells are collected.
[0195] At first, in step S 91 , a channel (exclusive backup channel) which is a self-backup channel and is not designated as a backup channel in adjacent BS is searched with reference to the WSCH list.
[0196] When an exclusive backup channel is found, in step S 92 , the channel selection processing is performed according to a spectrum etiquette for which fairness is considered as before.
[0197] On the other hand, when an exclusive backup channel is not present, in step S 93 , a determination is made as to whether more operating channels are required depending on the degree of a satisfaction for service quality in a self-cell. The service satisfaction ratio SSR is defined at a rate of the number of N sat of satisfied CPE relative to the number N CPE of CPE in the cell, and satisfaction is defined depending on whether a value obtained by giving a weight W to traffic of CPE exceeds a transmission rate which BS can provide per CPE as in Equation 1.
[0000] SSR= N CPE /N sat (Equation 1)
[0000] N sat =Countif i [R i ·N OPE /N CPE >W i ·λ i ] (Equation 2)
[0198] where Countif[ ] indicates the number of CPE for which a conditional equation in brackets matches, i is an integer of 1 to N CPE indicating an index of CPE, N OPE indicates the number of operating channels, and R indicates a (maximum) transmission rate per channel. R i may be a constant not depending on CPE if a distance between BS and CPE, or the like is not considered.
[0199] When it is determined that SSR exceeds a predetermined value and an operating channel does not need to be found any more, the processing ends.
[0200] In step S 94 , a determination is made as to whether channel negotiation is possible based on the determination that more operating channels are required in step S 92 . The determination is made depending on whether there is found an adjacent cell, which is operating in multi-channel, and whose CSA (Cell Service Availability) value is larger than CSA of its self-cell, and is not reversed (not larger than a ceded adjacent cell) even if the cell cedes one channel to the self-cell. The CSA value is defined as the reciprocal of a sum of traffic processing times of each CPE in the cell as in Equation 3.
[0000] CSA={Σ i [W i ·N OPE /N CPE )]} −1 (Equation 3)
[0201] Therefore, in order to make the determination in step S 93 or S 94 , SSR or CSA, or a value used for calculating the same needs to be exchanged between adjacent BSs previously or just in real time.
[0202] Then, in step S 95 , when it is determined that channel negotiation is possible, the channel negotiation is executed and a channel is acquired (ceded) from the destination.
[0203] On the other hand, when it is determined that channel negotiation is impossible, in step S 96 , a determination is made as to whether conventional self co-existence is to be achieved. That is, if N OPE =0 is established and a SC mode (Self Co-existence mode) is executable, it is determined that self co-existence is to be achieved.
[0204] When the SC mode is executable, in step S 97 , self co-existence defined in the IEEE802.22 is executed. That is, when a channel which is a self-backup channel and an operating channel in an adjacent cell is arbitrarily selected, a right to operate a channel is acquired in units of frame by random algorithm called ODFC, and the channel is shared between cells in a time division manner, or when a downstream transmission/reception period (DS: Down Stream) and an upstream transmission/reception period (US: Up Stream) are synchronized between cells thereby to avoid an interference, channel sharing is realized.
[0205] FIG. 16 is a flowchart of messages in channel negotiation in step S 94 . A channel release request (CHN-REQ), a channel release time notification (CHN-RSP), a channel release time acknowledgement response (CHN-ACK) and a channel release completion (CHN-CPLT) are sequentially exchanged. The messages are management messages, and are sent in SCW (Self Coexistence Window) rather than downstream burst.
[0206] A channel release request includes the CSA values of negotiation source and negotiation destination, and BS at the negotiation destination, which receives the channel release request, verifies it, and may return a channel release time notification (CHN-RSP) including an action code indicating denial depending on a verification result or the like.
[0207] An index such as SSR or CSA is used in step S 92 or S 93 according to the present example, but is not limited thereto. The reason why two indexes are used in the present example is as follows. That is, this is because loads given to BS may not appear quantitatively in SSR when a specific CPE traffic is so large, and if SSR is used in step S 93 , a traffic of the cell may not be allowed after channel release.
Fourth Example
[0208] In the present example, there will be described an operation when a plurality of CHUs are initialized at the same time, such as on activation in Examples 1 and 2, or an exemplary clarified format of a management message. Unless otherwise noted, the structure and functions according to Example 1 and 2 will be employed.
[0209] FIG. 17 is a flowchart of a channel addition processing performed between BS 2 and CPE 7 according to the fourth example.
[0210] The flow in FIG. 17 is different from FIG. 8 according to Example 1 in that step S 101 in which BS-CAM 41 determines whether unused BS-CHU remains is added after step S 8 , and step S 102 in which CPE-CAM 81 determines whether unused CPE-CHU 71 remains is added after step S 16 .
[0211] Thereby, on the BS 2 side, when a process from the operation start request in step S 2 to the operation start preparation completed notification in step S 8 is completed, a determination in step S 101 is made, and the processing can explicitly proceed to the operation start request (S 2 ) for other unused BS-CHU.
[0212] On the CPE 7 side, when a process from the BS search instruction in step S 12 to the continuation notification in step S 18 is completed, a determination in step S 102 is made, and the processing can explicitly proceed to the BS search instruction (S 12 ) for other unused CPE-CHU.
[0213] Since only a reception operation such as BS search may be freely performed on unused CPE-CHUs, BS search instructions with different search ranges may be provided at the same time on a plurality of unused CPE-CHUs in step S 12 . A BS detection notification is sequentially made in step S 14 from CPE-CHU which successfully performs BS detection, and CPE-CHU which does not successfully perform detection to the end adds a band not searched by the CPE-CHUs which successfully perform detection to the search range.
[0214] FIG. 18 is another flowchart of the channel addition processing performed between BS 2 and CPE 7 according to the fourth example.
[0215] The flow in FIG. 18 illustrates the channel addition processing when at least one of BS-CHU 13 and CPE-CHU 71 is already operated and a management message is communicable therebetween. It is different from FIG. 17 in that steps (S 103 to S 105 ) of notifying aggregation information on multi-channel operation including channel number or the like from BS 2 to CPE 7 are provided before step S 1 .
[0216] At first, in step S 103 , BS-CAM 41 periodically transmits aggregation information to at least one BS-CHU 13 a in operation when the multi-channel operation is started and during the operation. Aggregation information is desirably transmitted also after the channel addition, stop and switch processings are performed.
[0217] In step S 104 , BS-CHU 13 a transmits the received aggregation information as a management message (CAM-AIF: Channel Allocation Manager-Aggregation InFormation) to CPE 7 . The CAM-AIF message is preferably transmitted from all of BS-CHUs 13 (in a channel to be added now and other channel to be aggregated) in operation.
[0218] In step S 105 , CPE-CHU 71 a in CPE 7 receiving the aggregation information transfers the aggregation information to CPE-CAM 81 .
[0219] The aggregation information and management messages handled in steps S 103 to 105 include parameters necessary for the CAM-AIF message illustrated in Table 6. Type number is essential only for management messages, but a management message may be obtained on transmission from BS-CAM 41 , and BS-CHU 13 a or CPE-CHU 71 a in progress does not need to understand the management message.
[0000]
TABLE 6
CAM-AIF message format
Syntax
Size
Notes
CAM-AIF_Message_Format( ) {
Management Message Type = 41
8 bits
Aggregation Information
1 bit
0: Aggregation on
1: Aggregation off
Maximum Aggregation Channels
3 bits
The number of maximum aggregation
channels allowed in CPE.
For (i=0;i < Maximum Aggregation
List of the channel informations that are
Channels;i++){
available for channel aggregation in CPE.
Channel Number [i]
8 bits
}
}
[0220] In Table 6, “Maximum Aggregation Channels” is defined to be equal to or less than the number of BS-CHUs 13 to be subject to multi-channel operation in BS 2 . CPE 7 is prohibited from performing multi-channel operation beyond the number, and thus useless BS search is not performed. When a ratio between multi-channel operation CPE and normal operation CPE is to be controlled, lower “Maximum Aggregation Channels” may be set. “Channel Number[i]” is as many listed channel numbers (carrier index) or the like as “maximum Aggregation Channels.”
[0221] The flow of a channel switch processing performed between BS 2 and CPE 7 according to the fourth example is basically the same as Example 1 illustrated in FIG. 9 . The CH switch request in step S 33 is a CAM-SWH message newly defined as indicated in Table 7, and the CH switch request in step S 31 includes parameters necessary for CAM-SWH.
[0000]
TABLE 7
Syntax
Size
Notes
CAM-SWH_Message_Format( ) {
Management Message Type = 44
8 bits
Transaction ID
16 bits
Confirmation Needed
1 bit
0: No confirmation needed
1: Confirmation needed
Switch Mode
1 bit
0: no restriction on transmission until the
scheduled channel switch
1: addressed CPE shall transmit no further
frames until the schedules channel switch.
Switch Count
8 bits
The number of frames until the BS sending
the switching operating channel message
switches to the new operating channel.
Switch Channel Number
8 bits
Specified destination for channel switch
request.
}
[0222] “Transaction ID” is directed for ignoring messages other than a first message when a plurality of messages with the same value arrive, and is generally incremented and used each time a message requiring Transaction ID is newly issued. “Switch Channel Number” is a channel number (carrier index) or the like at the switch destination. The message is assumed to be transmitted only from a channel at the switch source irrespective of whether “Aggregation Type” is “Diversity mode” or “Bulk transmission mode”, and is not provided with information on the switch source. Though not recommended, when transmission is performed from a channel other than the channel at the switch source, CPE can specify the switch source in consideration of other information (such as continuity of Transaction ID). “Confirmation Needed” is a flag indicating whether to request CPE 7 to make a reception response (S 37 ). When the flag is 1, a quot; CAM-SWH-ACK” message indicated in Table 8 is newly defined as a reception response responded by CPE 7 in S 37 . CAM-SWH-ACK has to be responded from only the channel at the switch source, too.
[0000]
TABLE 8
CAM-SWH-ACK message format
Syntax
Size
Notes
CAM-SWH-ACK_Message_Format( ) {
Management Message Type = 45
8 bits
Transaction ID
16 bits
Confirmation Code
8 bits
7.7.24
}
[0223] “Confirmation Code” is defined by “7.2.24 Confirmation codes” in the 802.22. “Transaction ID” employs the same value as the CAM-SWH message.
[0224] The flow of a channel stop processing performed between BS 2 and CPE 7 according to the fourth example is basically the same as Example 1 illustrated in FIG. 10 . A quot; CAM-STP” message indicated in Table 9 is newly defined as an operation stop request in step S 53 , and a quot; CAM-STP-ACK” message indicated in Table 10 is newly defined as an operation stop reception response in step S 57 . The messages are assumed to be transmitted and received only in a channel to be stopped similarly to channel switching, and information on a channel to be stopped is not particularly provided.
[0000]
TABLE 9
CAM-STP message format
Syntax
Size
Notes
CAM-STP_Message_Format( ) {
Management Message Type = 42
8 bits
Transaction ID
16 bits
Confirmation Needed
1 bit
0: No confirmation needed
1: Confirmation needed
Stop Channel Number
8 bits
Specified destination for channel stop
operation request.
}
[0000]
TABLE 10
CAM-STP-ACK message format
Syntax
Size
Notes
CAM-STP-ACK_Message_Format( ) {
Management Message Type = 43
8 bits
Transaction ID
16 bits
Confirmation Code
8 bits
7.7.24
}
[0225] In the present example, the messages between BS and CPE, such as CH switch request in step S 33 , are assumed as management messages, but not limited to such broadcast transmission, unicast or multicast transmission toward only CPE necessary to be switched may be possible. Thereby, when a specific channel is intensively accessed, the channels to be allocated to CPE can be dispersed.
[0226] The scope of the present invention is not limited by the above-described examples for communication between BSs, and the processings performed in BS in the above examples may be intensively controlled by a server, manager or the like installed over the Internet. For example, channel negotiation may be performed via the Internet by encapsulating a management message, not limited to via wireless communication between BSs. Alternatively, a channel operation state in each BS may be monitored and controlled by a server or manager, and the equivalent advantages to the object of the present invention can be obtained even if each BS makes a channel request to the server.
[0227] The physical layers in CHU may be collectively configured, not being configured in a multisystem, and signals received in a plurality of channels by a digital signal processing in the physical layers may be subject to diversity combination.
REFERENCE SIGNS LIST
[0000]
2 , 120 , 220 : Base station (BS),
5 : Internet, 6 : DB server,
7 , 170 , 270 : Terminal device (CPE),
13 , 130 : Wireless communication unit (BS-CHU: BS-CHannel transceiver Unit),
14 , 72 , 124 : Channel unit control manager (CHU-M: CHU-Manager),
15 , 16 : Inter-unit I/F,
41 : Channel allocation manager (BS-CAM: BS-Channel Allocation Manager),
42 : CPE management unit,
43 : Management information processing unit (MIB), 44 : DB access control unit,
45 : Communication data control unit, 46 : Sensing control unit,
71 : CPE-CHU,
81 : Channel allocation manager (CPE-CAM),
125 : Sensing unit,
131 : MAC processing unit, 132 : PHY processing unit,
133 : Transmission/reception unit (Tx/Rx), 134 : Management information processing unit,
135 : Inter-unit I/F, 136 : Antenna
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The present invention introduces a multichannel MAC into a white-space-using system. A base station and a terminal station are each configured from a plurality of wireless communication units and centralized control units thereof. Each of the wireless communication units wirelessly transmits/receives for one channel. The base station operates one or more channels according to white-space-channel status, and is assigned to a terminal station. When operating a plurality of channels, it is possible to select a redundancy mode for assigning data by duplicating the terminal-station data in a plurality of channels, and a high-speed mode for dividing the data and distributing the data among the plurality of channels.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 15/096,846, filed on Apr. 12, 2016, entitled PROBE TIP AND INFUSION SLEEVE FOR USE IN OPHTHALMOLOGICAL SURGERY (Atty. Dkt. No. WHER-33089), which issued as U.S. Pat. No. 9,713,671, on Jul. 25, 2017. U.S. patent application Ser. No. 15/096,846 is a continuation of U.S. patent application Ser. No. 14/489,007, filed Sep. 17, 2014, entitled PROBE TIP AND INFUSION SLEEVE FOR USE IN OPHTHALMOLOGICAL SURGERY (Atty. Dkt. No. WHER-32333), which is a continuation of U.S. patent application Ser. No. 13/888,699, filed May 7, 2013, entitled PROBE TIP AND INFUSION SLEEVE FOR USE IN OPHTHALMOLOGICAL SURGERY (Atty. Dkt. No. WHER-31704), now U.S. Pat. No. 8,840,624, issued Sep. 23, 2014, which is a continuation of U.S. patent application Ser. No. 12/169,483, filed Jul. 8, 2008, entitled PROBE TIP AND INFUSION SLEEVE FOR USE WITH OPHTHALMOLOGICAL SURGERY (Atty. Dkt. No. WHER-28754), now U.S. Pat. No. 8,435,248, issued May 7, 2013. U.S. patent application Ser. No. 12/169,483 claims benefit of U.S. Provisional Application No. 60/977,705, filed Oct. 5, 2007, entitled PROBE TIP AND INFUSION SLEEVE FOR PHACO EMULSIFICATION PROCESS FOR REMOVING THE HUMAN LENS IN CATARACT SURGERY AND REFRACTIVE LENS PROCEDURES (Atty. Dkt. No. WHER-28342). U.S. patent application Ser. Nos. 15/096,846, 14/489,007, 13/888,699, 12/169,483, 60/977,705 and U.S. Pat. Nos. 9,713,671, 8,840,624 and 8,435,248 are incorporated by reference herein in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to probe tips for use in the removal of a human lens from an individual's eye, and more particularly, to a curved probe tip and sleeve design for use with optical procedures such as cataract surgery and refractive and presbyopic lens exchange surgery.
BACKGROUND
[0003] Phacoemulsification techniques for the removal of cataracts or the removal of a human lens in an individual's eye for purpose of refractive lens correction requires the use of high frequency ultrasound generated movements of a metal probe tip combined with the infusion of fluids to maintain and pressurize the human eye. The device for providing these functionalities is generally referred to as a phacoemulsification probe. The phacoemulsification probe uses subtle aspiration or suction functions to remove emulsified lens material within the eye of an individual. The material within the eye may be emulsified using ultrasonic processes in order to break down material within the eye. These types of probes are used during cataract surgery, as well as for lens removal purposes for refractive and presbyopic lens correction. In currently used technologies, the phacoemulsification probes, their tips and associated sleeves, are designed to generate linear movement of the tip via ultrasound and to provide the coaxial infusion of fluids within the eye by a sleeve which projects fluid in the same direction as tip movement. However, this infusion of fluid is in a competitive direction to the direction of suction of the probe tip which is used for aspirating lens material that has been emulsified via the ultrasonic emissions of the probe tip.
[0004] The configuration of existing phacoemulsification probes use straight probe tips having the infusion sleeve coaxial with the probe tip to inject fluid along the same axis as the ultrasonic emissions of the probe tip. This generates a more linear to and fro motion with respect to the straight or beveled tip of the phacoemulsification probe that can potentially run the risk of damaging sensitive support structures of the human lens, such as zonules. The linear back and forth movement of existing probes can cause damages to the inner structures of the capsular sac or support structures of the lens since the movements may be directly into the structures and the fluidic infusion may also be directly at the structures in addition to the ultrasonic emissions of the tip. These combined forces can, for example, cause turbulent endotheliopathy, which may damage the inside of the lining of the cornea.
[0005] Another problem arising from the linear to and fro motion of existing phacoemulsification probes, arises from “coring.” “Coring” involves a situation wherein the tip of the phacoemulsification probe becomes plugged with emulsified materials that are being broken down and aspirated, particularly during linear emulsification techniques. Thus, there is a need for an improved phacoemulsification tip for use in ophthalmological procedures involving the removal of materials from the capsular lens sac that overcomes the problem of existing tips such as projection of fluids in a non competitive direction from which materials are attempting to be aspirated, risking damage to sensitive and internal structures of the human eye, and the prevention of coring when using phacoemulsification probes.
SUMMARY
[0006] The present invention as disclosed and described herein, in one aspect thereof, comprises an aspiration probe tip for use in surgical procedures that includes a body defining a first channel therein for aspirating material therethrough from a surgical region along a first vector. The body includes a straight portion connected to a first end and a curved portion connecting the straight portion to a second end. A fluid sleeve surrounds at least a portion of the body and defines a second channel between the fluid sleeve and the body for injecting a fluid into the surgical region along a second vector. An end of the fluid sleeve securely fits over the body to substantially seal the end of the fluid sleeve. The fluid sleeve further defines an aperture for injecting fluid along the second vector from the second channel into the surgical region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:
[0008] FIG. 1 illustrates the various structures of a human eye;
[0009] FIG. 2 illustrates a prior art phacoemulsification tip and associated sleeve;
[0010] FIGS. 3 a -3 e illustrate the various steps involved in the use of a phacoemulsification probe with respect to cataract surgery;
[0011] FIG. 4 a provides a cross-sectional view of the phacoemulsification tip and associated sleeve of the present disclosure;
[0012] FIG. 4 b illustrates an alternative embodiment of the fluidic sleeve;
[0013] FIG. 5 illustrates the phacoemulsification probe tip of FIG. 4 with the sleeve removed;
[0014] FIG. 6 illustrates the sleeve that is placed over the phacoemulsification probe tip;
[0015] FIG. 7 is a functional block diagram of a phacoemulsification machine;
[0016] FIG. 8 illustrates the various force vectors which may be utilized within utilizing the phacoemulsification probe tip to remove a mass such as a cataract within an eye; and
[0017] FIGS. 9 a and 9 b illustrate a further use of the probe.
DETAILED DESCRIPTION
[0018] Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of the probe tip and infusion sleeve for use with ophthalmological surgery are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments.
[0019] Referring now to the drawings, and more particularly to FIG. 1 , there is provided an illustration of the major structures of the human eye. The structures involved with the phacoemulsification and other optical procedures relevant to the improved phacoemulsification probe tip and sleeve of the present disclosure are all within the anterior segment 102 consisting of the anterior chamber 104 and the posterior chamber 106 . The anterior chamber 104 comprises those structures from the cornea 108 to the iris 110 . The cornea 108 covers the anterior chamber 104 and comprises the exterior of the eye. The iris 110 expands and retracts to alter the size of the pupil and adjust the amount of light entering the human eye. The lens 112 is used for focusing light passing through the pupil on the retina 118 . The lens 112 is contained within the capsular sac consisting of the anterior capsule 114 and the posterior capsule 116 . Zonule fibers 120 are used for supporting the lens 112 within the capsular sac. A cataract is an opacity that develops within the lens 112 . Cataract surgery or refractive lens procedures involve a process for piercing the anterior capsule 114 to remove the lens 112 and other materials contained within the capsular sac.
[0020] Referring now to FIG. 2 , there is illustrated a prior art phacoemulsification probe that is used for removing cataract and lens material from the capsular sac of a human eye. The phacoemulsification probe 202 consists of a stainless steel or metal tip 204 that is inserted within an incision made within the cornea and anterior capsule to aspirate emulsified material through a small opening 206 within the end of the probe tip 204 . Additionally, a fluidic sleeve 208 is placed over the probe tip 204 and a fluid material may then be injected along the axis of the tip 205 through the annular chamber formed between the probe tip 204 and the fluidic sleeve 208 . The fluid injected into the process passes out of the annular opening 210 of the fluidic sleeve 208 . As discussed previously, one problem with the design of existing phacoemulsification probes is that the aspiration of emulsified materials occurs generally in the direction indicated by arrow 212 while the fluid injected into the process from the chamber between the fluidic sleeve 208 and the probe tip 204 occurs generally in the direction indicated by arrow 214 . Thus, the aspirated materials and the fluids injected into the process are occurring in opposite directions working against each other.
[0021] Referring now to FIGS. 3 a -3 e , there are more fully illustrated the various processes involved within the phacoemulsification surgery procedure. Initially, as generally indicated at FIG. 3 a , a micro incision of 1 mm-3 mm is made in the human eye at the junction of the clear cornea and the white of the eye (i.e., a clear corneal incision) to facilitate placement of the instrumentation for performing the phacoemulsification procedure. A side incision is also made. According to one technique these micro incisions are made either directly on the axis of the astigmatism of the patient's eye, or 90 degrees away from it, depending on the ease of access of surgery and the requirement for correction of astigmatism pre or post operatively.
[0022] Once the incisions have been made, a viscoelastic substance is injected into the eye to maintain intraocular pressure. The viscoelastic substance is injected within the anterior chamber 104 described previously with respect to FIG. 1 . This procedure is analogous to performing a procedure within a water balloon while maintaining the pressure within that water balloon without releasing the fluid from the pressurized structure. Once the viscoelastic substance is injected within the anterior chamber 104 of the human eye, a circular opening is made within the anterior capsule 114 to create access to the lens 112 . The removal of the anterior surface of the lens capsule is referred to as capsulorhexis.
[0023] The phacoemulsification probe is inserted through the incision within the cornea as illustrated in FIG. 3 b to enable access to the lens 112 via the hole made within the anterior capsule 114 . Using ultrasonic emissions from the probe, the cataract within the lens 112 of the eye is broken up (emulsified) as illustrated generally in FIGS. 3 b and 3 c . The emulsified cataract material and lens is aspirated from the capsular sac using a combination of fluids injected within the capsular sac from the phacoemulsification probe and the aspiration functionalities of the probe.
[0024] This procedure can be analogized with the capsular sac being considered to be a common candy such as an M&M. The circular opening is made within the candy coating of the M&M on its anterior surface (i.e., capsulorhexis). The chocolate within the candy coating is then emulsified and aspirated from within the candy coating. This leaves a c-shaped bowl comprising the posterior surface of the M&M. In the present disclosure, the c-shaped bowl comprising a saran wrap-like biological tissue called the posterior capsule is allowed to remain within the eye to support a replacement lens inserted within the capsular sac as described hereinbelow.
[0025] Once the cataract and lens fragments have been aspirated from the capsular sac additional viscoelastic fluid may be injected into the empty capsular sac to expand it to facilitate placement of a folded intraocular lens (IOL). A foldable intraocular lens implant is made of silicon or acrylate and has the appropriate power of correction for the patient's vision. A folded IOL replaces the existing crystalline lens of the eye that has been removed due to the cataract. It normally comprises a small plastic lens with acrylate or silicone side struts, called haptics, to hold the lens in place within the capsular sac of the eye. The prescription of the IOL is established by the patient and the doctor in accordance with the needs of the patients such as is done for glasses or contact lenses.
[0026] The IOL is injected within the capsular sac as illustrated in FIG. 3 d using a lens injector through the incision that was previously used by the phacoemulsification probe. The use of a foldable IOL enables the lens to be rolled for insertion into the capsular sac through the very small incision made previously thus avoiding the need for stitches in the eye caused by a larger incision. After injection within the capsular sac using the lens injector as illustrated in FIG. 3 d , the intraocular lens expands within the capsular sac as illustrated in FIG. 3 e . The intraocular lens is supported by the posterior portion of the capsular sac which remains intact. The injected viscoelastic material may then be removed via aspiration and no sutures are required after the surgery due to the small size of the incisions that were made.
[0027] Referring now to FIG. 4 a , there is illustrated the phacoemulsification probe and fluidic sleeve of the present disclosure. The phacoemulsification probe 402 rather than comprising a straight probe tip includes a curved probe tip 404 . The end of the probe tip 404 is curved such that the axis 406 at the end of the tip is at an angle of approximately 20-45 degrees with respect to the main axis 408 of the probe tip 404 . However, it should be realized that the angle between the curved portion of the probe tip 404 and the main axis 408 of the probe 402 could be set to any angle. The phacoemulsification probe tip 404 is constructed of titanium, stainless steel or other type of metallic material useful in surgical procedures. The opposite end of the probe tip 404 connects with a connector for connecting to the main probe body. The probe tip 404 also defines therein a passageway 410 enabling the aspiration of materials from the eye of a patient through an opening 412 . The probe tip 404 is also connected to additional components within the probe body and probe machine enabling the probe tip 404 to vibrate at and emit ultrasonic frequencies. In addition to the ultrasonic vibrations, the tip 404 may be made to rotate along a circular axis 424 about the central axis 408 of the probe tip. The vibration of the probe tip 404 at the ultrasonic frequencies enables a surgeon to sculpt and emulsify cataracts or natural lenses while suctioning the aspirated particles into the opening 412 and the hollow passageway 410 running through the body of the tip 404 .
[0028] Surrounding the body of the probe tip 404 is a fluidic sleeve 414 . The fluidic sleeve 414 is made of silicon, plastic or metallic material and includes an aperture 416 enabling the expulsion of a fluid in an initial direction away from the opening 412 that is used for aspirating materials into the phacoemulsification probe 402 . This enables fluid to be expelled in a non-competitive vector to the vector of suction. The end of the fluidic sleeve 414 closest to the opening 412 of the probe tip 404 is closed by having its edges 418 slide over a protrusion 420 within the body of the probe tip 404 . The protrusion 420 is an annular protrusion completely surrounding the exterior surface of the probe tip 404 . The protrusion 420 enables the open end 418 of the fluidic sleeve 414 to fit snugly over the probe tip 404 and seal the end of the fluidic sleeve such that any fluid injected into the sleeve will pass out the aperture 416 . Fluid is provided to the aperture 416 through an annular area 422 that is defined between the inner wall of the fluidic sleeve 414 and the outer surface of the probe tip 404 .
[0029] Referring now also to FIG. 4 b , there is illustrated an alternative embodiment wherein the fluidic sleeve 414 rather than having an aperture 416 on the inner radius of the probe tip includes an aperture 430 on the external radius of the probe tip. In this case, the vector of expulsion 432 would still be non-competitive with the vector of aspiration into the general 410 of the probe tip 404 . Additionally, it is noted that the configuration of the aperture 430 illustrated in FIG. 4 b is a shark gill configuration comprising a curved slit in the fluidic sleeve 410 . Rather than using only a single slit for the aperture 430 , multiple slits may be utilized in alternative configurations. It is noted that placement of the fluid aperture for the fluidic sleeve 410 on the external radius of the probe tip or the internal radius of the probe tip may be selected based upon a particular application of the probe tip. Thus, depending upon the application, the vector of expulsion 432 of the fluidic sleeve 414 may be configured in any number of directions that are non-competitive with the vector of aspiration of the probe tip in order to better provide different uses of the probe tip. Additionally, rather than the shark fin configuration illustrated in FIG. 4 b or the small opening configuration illustrated in FIG. 4 a any number of configurations may be utilized for the fluid aperture from the fluidic sleeve 414 .
[0030] Referring now to FIG. 5 , there is illustrated a perspective view of the probe tip 404 . As described previously, the probe tip 404 is made of a metallic material and defines an opening 412 for aspirating materials removed from a patient's eye in the end of the probe 404 . The annular protrusion 420 is used for sealing the open end of the fluidic sleeve 414 as described hereinabove. Connector 405 allows connection of the probe tip 404 to the rest of the body of the phacoemulsification probe 402 .
[0031] Referring now also to FIG. 6 , there is provided an illustration of the fluidic sleeve 414 which surrounds the probe tip 404 . The top edge 418 of the fluidic sleeve 414 defines an opening through which the probe tip 404 is inserted. The opening 602 is sealed by the top edge 418 fitting snugly over the protrusion 420 on the phacoemulsification probe tip 404 . The fluidic sleeve 414 is also curved at an angle similar to that of the phacoemulsification probe tip 404 such that a consistent sizing of the annular region 422 between the inner wall of the fluidic sleeve 414 and the external wall of the probe tip 404 is provided. Since the opening 602 of the fluidic sleeve 414 is sealed closed by the snug fit of edge 418 over the protrusion 420 , all fluids which are expelled from the fluidic sleeve are expelled through the aperture 416 . The configuration of the aperture 416 can be established to enable the fluids to be expelled in any desired direction, opposite that from the material which is being aspirated into the opening 412 of the probe tip 404 .
[0032] Referring now also to FIG. 7 , there is illustrated a functional block diagram of a phacoemulsification machine 702 and an associated phacoemulsification probe 704 . The phacoemulsification machine 702 includes sonic control components 706 for controlling the ultrasonic vibrations of the probe 704 for breaking up the cataract and lens structures, an irrigation control component 708 for controlling the flow of material through the chamber between the fluidic sleeve and the probe tip and aspiration control components 710 for controlling the aspiration of cataract and lens material from the capsular sac. The phacoemulsification machine 202 and probe 204 enables the integration into a single unit the irrigation, aspiration and ultrasound capabilities needed to break up and remove cataractous lenses from the eyes. An optical surgeon activates these capabilities in succession typically by depressing a foot pedal 712 associated with the phacoemulsification machine 702 .
[0033] Initially, irrigation is provided by the irrigation controlled component 708 to the probe 704 typically by gravity feed from a bottle to flush the surgical site, maintain pressure in the anterior chamber of the eye to keep it from collapsing when aspiration is applied and to cool the probe tip during oscillations. Next, the aspiration control components 710 are activated to draw fluid and lens fragments toward and through the probe tip into a collection container. The aspiration components 710 employ different ophthalmic surgical systems such as a peristaltic pump, a venturi or diaphragm pump, etc. in order to perform the aspiration functions. The ultrasound control component 706 initiates the ultrasonic vibrations in order to emulsify the lens of a patient.
[0034] Maintaining control of the phacoemulsification probe 704 requires that the surgeon be able to achieve a balance between irrigation and the parameters of flow and vacuum. Flow describes the rate at which fluid and lens fragments travel toward and through the probe tip 404 . The vacuum describes the suction force that holds material to the probe tip. During surgery, aspiration draws the lens and lens fragments toward the probe tip and the vacuum holds the lens or fragments at the tip while the ultrasonic waves push them away. The effects of both cavitation and mechanical impact cause the lens material to break apart. When small enough, the fragments are aspirated through the probe tip at a rate determined by the aspiration rate. Too high a flow rate will cause fragments to move too fast, creating turbulence within the eye. Too high a vacuum can cause a surge after an occluded lens piece is quickly emulsified.
[0035] The phacoemulsification machine 702 allows surgeons to control the aspiration parameters using either a fixed or linear mode of operation. In fixed modes, the unit provides aspiration at a set level as established by the aspiration control component 710 when the surgeon depresses the foot pedal. In linear mode, the surgeon's increasing depth of foot pedal depression controls one of the aspiration parameters. Operating the unit at a fixed mode is relatively straight forward. However, achieving the desired clinical performance also requires an understanding of the unit's linear mode of operation.
[0036] Referring now to FIG. 8 , there are illustrated the various forces used by the phacoemulsification probe 402 to remove lens material from the capsular sac of an eye. As described previously, the curvature of the probe tip may be such that the angle between the axis 406 of the opening for aspirating material from an eye and the main axis 408 of the probe 402 can be an angle θ anywhere between 20 and 45 degrees. However, angles of other values may also be utilized. The curved shape of the probe 402 and the aperture 416 providing the fluid infusion to the capsular sac that does not oppose the direction of aspiration provides several advantages over existing phacoemulsification probe configurations. The curved tip provides a configuration wherein the coaxial ultrasound generation along axis 408 provides non-coaxial tip movement at the probe tip 802 . Additionally, the curvature of the probe tip enables, with a slight rotation of the surgeon's hand, a three-dimensional movement of the tip 802 within the eye. This facilitates the emulsification procedure and enables the surgeon to generate tip movement in a circumlinear fashion within the capsular bag. This allows the direction of aspiration into opening 412 to be centrifugal to the human lens substance. The curvature also enables the ultrasonic energy of emulsification to be directed in a two dimensional fashion via the curved tip design along the main axis 408 and along the axis 406 of the curved end and allows the tip to move three dimensionally facilitated by the surgeon's movement and control of the rotational aspects of the emulsification probe 402 . Thus, the probe tip 802 may be placed within the circumference of the cataract and allows the aspiration to function in a centrifugal fashion, removing the lens material in a plane parallel to the plane of the iris and parallel to the plane of the human lens equator. This is different from the to and fro motion of straight tip phacoemulsification probe configurations described previously in prior art designs.
[0037] In addition to the sonic vibrations, the probe tip may be made to rotate along a circular axis 810 , as illustrated in FIG. 8 , to create additional ultrasonic vibrations for breaking up cataract or lens materials. Using the described configuration, the probe tip will have three degrees of motion. The axis of ultrasonic vibration in the motion of the tip may first move along the main axis 408 parallel to the long axis of the probe. The tip may also vibrate along a second axis 406 obliquely displaced from the long axis of the tip by virtue of the curved and beveled tip of the probe. Finally, the tip may have included therewith coaxial rotation about an axis 810 either generated by the surgeon or by coaxial rotation of the tip generated by additional ultrasonic components.
[0038] Additionally, the fluidic sleeve design having the opening 416 to provide for fluid infusion that does not compete with the direction of aspiration of the probe tip provides a cyclonic movement of fluid within the eye as opposed to fluidic infusion directly in competition with the vector of aspiration. As can be seen in FIG. 8 , fluid is ejected from opening 416 in a direction illustrated generally by arrows 804 . Similar motion can be provided by an aperture on the external radius of the sleeve. The combination of the shape of the capsular sac, the direction of the fluid from the opening 416 and the aspiration into opening 412 of the probe tip 404 contributes to the cyclonic motion of the fluid within the eye around any mass 806 that is being emulsified by the ultrasonics of the probe tip 404 . As particles of the mass 806 are broken down into a small enough size by ultrasonic vibrations of the probe tip 404 by bimanually dismantling the nucleus, the cyclonic motion of the fluid in the eye rotates the emulsified particles to the opening 412 of the probe tip enabling them to be aspirated out of the capsular bag. Thus, the cyclonic movement of the fluid within the eye directs the lens materials toward the opening 412 of the probe tip rather than creating force vectors that would direct emulsified components away from the aspiration of the probe tip.
[0039] The improved configuration of the probe provides a number of advantages over the prior art. The described configuration is specifically adaptable to hard nuclei whereby a more anterior emulsification of a hard lens causes turbulent endotheliopathy and damage to the insides of the cornea. The more linear to and fro motion of a straight or beveled tip probe places more stress on the support structures of the human lens (zonules). With the probe tip described herein, the forces are more indirectly directed against the hard nuclei. The stresses upon the zonules are minimized when treating large hard nuclei using a process wherein the hard nuclei may be grasped by the tip of the probe 902 as shown generally in FIG. 9 a . Once the hard nuclei has been grasped, the probe tip may be rotated such that the hard nuclei and associated lens are moved away from the anterior portion of the capsular sac 906 . When the hard nuclei 904 is moved away form the anterior portion capsular sac 906 as illustrated generally in FIG. 9 b , the fluid vectors 908 from the aperture of the fluidic sleeve 910 of the probe tip 902 assist in keeping the capsular sac 906 open and away from the hard nuclei 904 . The surgeon my then dissect the hard nuclei 906 into as many pieces as necessary in order to assist in it's aspiration through the probe tip.
[0040] This method is also efficient in removing softer, more gelatinous lens material from younger patients, or patients with less nuclear hardening for the purposes of early cataract removal, refractive lensectomy or presbyopic lens exchange. A configuration of the described lens probe results in fewer complications, such as endothelial cell trauma, retinal detachment, corneal edema, post-operative inflammation or wound treatment while facilitating better immediate post-operative visual acuity and function.
[0041] The angulation of the tip in a curved fashion from the main body thereof prevents coring of and plugging of lens material within the opening 412 by cataract or refractive or presbyopic lens substance. This prevents stopping or plugging during aspiration and facilitates improvement of coring problems caused during phacoemulsification procedures. The above-described configuration includes a number of improvements over existing designs with respect to the infusion vectors and aspiration and emulsification vectors that are competitive in existing configurations. There have not previously been designed or made available a tip and sleeve that utilizes the anatomy of a human lens as a guide, the generation of ultrasonic movements intentionally oblique to the coaxial vector of ultrasonic generation, the surgeon's control of the third rotational function of tip movement and to intentionally provide aspiration and infusion fluidics in opposite directions designed specifically to respect the lens anatomy and to facilitate aspiration by the thus created fluidics instead of to unknowingly compete with it. This combination generates a cyclonic fluidic rotation of the lens material and allows the lens material to move toward the aspiration tip within the capsular bag thus facilitating emulsification and aspiration removal of the lens material.
[0042] It will be appreciated by those skilled in the art having the benefit of this disclosure that this probe tip and infusion sleeve for use with ophthalmological surgery provides improvements over existing designs. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.
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An aspiration probe tip for use in surgical procedures includes a body defining a first channel therein for aspirating material therethrough from a surgical region along a first vector. The body includes a straight portion connected to a first end and a curved portion connecting the straight portion to a second end. A fluid sleeve surrounds at least a portion of the body and defines a second channel between the fluid sleeve and the body for injecting a fluid into the surgical region along a second vector. An end of the fluid sleeve securely fits over the body to substantially seal the end of the fluid sleeve. The fluid sleeve further defines an aperture for injecting fluid along the second vector from the second channel into the surgical region.
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RELATED U.S. APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO MICROFICHE APPENDIX
Not applicable.
FIELD OF THE INVENTION
The present invention relates to a duct coupler, and more particularly to a coupler for providing a water-tight joint between adjacent sections of duct used to provide a channel for multi-strand post-tensioning of concrete structures.
BACKGROUND OF THE INVENTION
For many years, the design of concrete structures imitated the typical steel design of column, girder and beam. With technological advances in structural concrete, however, its own form began to evolve. Concrete has the advantages of lower cost than steel, of not requiring fireproofing, and of its plasticity, a quality that lends itself to free flowing or boldly massive architectural concepts. On the other hand, structural concrete, though quite capable of carrying almost any compressive load, is weak in carrying significant tensile loads. It becomes necessary, therefore, to add steel bars, called reinforcements, to concrete, thus allowing the concrete to carry the compressive forces and the steel to carry the tensile forces.
Structures of reinforced concrete may be constructed with load-bearing walls, but this method does not use the full potentialities of the concrete. The skeleton frame, in which the floors and roofs rest directly on exterior and interior reinforced-concrete columns, has proven to be most economic and popular. Reinforced-concrete framing is seemingly a quite simple form of construction. First, wood or steel forms are constructed in the sizes, positions, and shapes called for by engineering and design requirements. The steel reinforcing is then placed and held in position by wires at its intersections. Devices known as chairs and spacers are used to keep the reinforcing bars apart and raised off the formwork. The size and number of the steel bars depends completely upon the imposed loads and the need to transfer these loads evenly throughout the building and down to the foundation. After the reinforcing is set in place, the concrete, a mixture of water, cement, sand, and stone or aggregate, of proportions calculated to produce the required strength, is placed, care being taken to prevent voids or honeycombs.
One of the simplest designs in concrete frames is the beam-and-slab. This system follows ordinary steel design that uses concrete beams that are cast integrally with the floor slabs. The beam-and-slab system is often used in apartment buildings and other structures where the beams are not visually objectionable and can be hidden. The reinforcement is simple and the forms for casting can be utilized over and over for the same shape. The system, therefore, produces an economically viable structure. With the development of flat-slab construction, exposed beams can be eliminated. In this system, reinforcing bars are projected at right angles and in two directions from every column supporting flat slabs spanning twelve or fifteen feet in both directions.
Reinforced concrete reaches its highest potentialities when it is used in pre-stressed or post-tensioned members. Spans as great as one hundred feet can be attained in members as deep as three feet for roof loads. The basic principle is simple. In pre-stressing, reinforcing rods of high tensile strength wires are stretched to a certain determined limit and then high-strength concrete is placed around them. When the concrete has set, it holds the steel in a tight grip, preventing slippage or sagging. Post-tensioning follows the same principle, but the reinforcing tendon, usually a steel cable, is held loosely in place while the concrete is placed around it. The reinforcing tendon is then stretched by hydraulic jacks and securely anchored into place. Pre-stressing is done with individual members in the shop and post-tensioning as part of the structure on the site.
In a typical tendon tensioning anchor assembly used in such post-tensioning operations, there are provided anchors for anchoring the ends of the cables suspended therebetween. In the course of tensioning the cable in a concrete structure, a hydraulic jack or the like is releasably attached to one of the exposed ends of each cable for applying a predetermined amount of tension to the tendon, which extends through the anchor. When the desired amount of tension is applied to the cable, wedges, threaded nuts, or the like, are used to capture the cable at the anchor plate and, as the jack is removed from the tendon, to prevent its relaxation and hold it in its stressed condition.
Multi-strand tensioning is used when forming especially long post-tensioned concrete structures, or those which must carry especially heavy loads, such as elongated concrete beams for buildings, bridges, highway overpasses, etc. Multiple axially aligned strands of cable are used in order to achieve the required compressive forces for offsetting the anticipated loads. Special multi-strand anchors are utilized, with ports for the desired number of tensioning cables. Individual cables are then strung between the anchors, tensioned and locked as described above for the conventional monofilament post-tensioning system.
As with monofilament installations, it is highly desirable to protect the tensioned steel cables from corrosive elements, such as de-icing chemicals, sea water, brackish water, and even rain water which could enter through cracks or pores in the concrete and eventually cause corrosion and loss of tension of the cables. In multi-strand applications, the cables typically are protected against exposure to corrosive elements by surrounding them with a metal duct or, more recently, with a flexible duct made of an impermeable material, such as plastic. The protective duct extends between the anchors and in surrounding relationship to the bundle of tensioning cables. Flexible duct, which typically is provided in 20 to 40 foot sections, is sealed at each end to an anchor and between adjacent sections of duct to provide a water-tight channel. Grout then may be pumped into the interior of the duct in surrounding relationship to the cables to provide further protection.
Several approaches have been tried to solve the problem of quickly, inexpensively and securely sealing the joints between adjacent sections of duct used in multi-strand post-tensioned applications. However, all prior art devices have utilized a plurality of arcuate sections which must be assembled at a joint around the ends of adjacent duct sections. Wedges, compression bolts or the like then are used to compress the joined sections into sealing engagement with the duct and with each other. Such prior art devices have been cumbersome to use and have proved somewhat unreliable in their ability to exclude moisture or other corrosive elements from the interior of the ducts.
Several patents have issued relating to duct couplers. For example, U.S. Pat. No. 5,320,319, issued on Jun. 14, 1994 to K. Luthi, describes a coupling element which is fitted with chamfered flanges. The sheaths of the coupler have protrusions which are inserted into the coupling element with a tubular element which forms the end of the sheaths. A sealing ring is inserted between each of the flanges and protrusions of the sheaths. The flanges and the protrusions are held together by sloping surfaces and by a groove worked within each socket. Also, U.S. Pat. No. 5,474,335, issued on Dec. 12, 1995 to the present inventor, describes a duct coupler for joining and sealing between adjacent sections of the duct. The coupler includes a body, flexible cantilevered sections on the end of the body adapted to pass over annular protrusions on the duct and locking rings for locking the cantilevered flexible sections into position, so as to lock the coupler onto the duct.
U.S. Pat. No. 5,775,849, issued on Jul. 7, 1998 to the present inventor, describes a coupler as used for ducts in post-tension anchorage systems. This duct system includes a first duct having a plurality of corrugations extending radially outwardly therefrom, a second duct having a plurality of corrugations extending radially outwardly therefrom, and a tubular body threadedly receiving the first duct at one end and threadedly receiving the second duct at the opposite end. The tubular body has a first threaded section formed on an inner wall of the tubular body adjacent one end of the tubular body and a second threaded section formed on the inner wall of the tubular body adjacent an opposite end of the tubular body. The threaded sections are formed of a harder polymeric material than the polymeric material of the first and second ducts. The tubular body has an outer diameter which is less than the diameter of the ducts at the corrugations. The first and second threaded sections have a maximum inner diameter which is less than the outer diameter of the ducts at the end of the ducts. First and second elastomeric seals are affixed to opposite end of the tubular body and juxtaposed against a surface of a corrugation of the first and second ducts.
U.S. Pat. No. 5,954,373, issued on Sep. 21, 1999 to the present inventor, describes a different type of duct coupler apparatus. The duct coupler apparatus of this patent includes a tubular body with an interior passageway between a first open end and a second open end. A shoulder is formed within the tubular body between the open ends. A seal is connected to the shoulder so as to form a liquid-tight seal with a duct received within one of the open ends. A compression device is hingedly connected to the tubular body for urging the duct into compressive contact with the seal. The compression device has a portion extending exterior of the tubular body. The compression device includes an arm with an end hingedly connected to the tubular body and having an abutment surface adjacent the end. The arm is movable between a first position extending outwardly of an exterior of the tubular body and a second position aligned with an exterior surface of the tubular body. A latching member is connected to an opposite end of the arm and serves to affix the arm in the second position. The abutment surface of the arm serves to push a corrugation of the duct against the seal and against the shoulder so as to form a liquid-tight seal between the duct and the interior of the coupler.
U.S. Pat. No. 6,764,105, issued on Jul. 20, 2004 to the present inventor, describes a duct coupler apparatus for use with precast concrete segmental construction. This coupler has a first duct, a first coupler member extending over and around an exterior surface of the first duct and having a seat opening adjacent an end of the first duct, a second duct, a second coupler member extending over and around an exterior surface of the second duct and a seat opening adjacent to an end of the second duct, and gasket received in the seats of the first and second coupler members. An external seal is affixed to an opposite end of the first coupler member and affixed to an exterior surface of the first duct. The seats of the first and second coupler members have slots facing one another. The gasket is received within these slots.
U.S. Pat. No. 6,752,435, issued on Jun. 22, 2004 to the present inventor, describes a symmetrical coupler apparatus for use with precast concrete segmental construction. This coupler member has a first duct, a first coupler member extending over and around an exterior surface of the first duct and an end opening adjacent an end of the first duct, a second duct, a second coupler member extending over and around an exterior surface of the second duct and an end opening adjacent to an end of the second duct, and a gasket received in the ends of the first and second coupler members. The gasket serves to prevent liquid from passing between the ends of the coupler members into an interior of either of the first and second ducts. An external seal is affixed to an opposite end of the first coupler member and affixed to an exterior surface of the first duct. An internal seal is interposed in generally liquid-tight relationship between an interior surface of the second coupler member and an exterior surface of the second duct.
U.S. Pat. No. 6,834,890, issued on Dec. 28, 2004 to the present inventor, teaches a coupler apparatus for use with a tendon-receiving duct in a segmental precast concrete structure. This coupler apparatus includes a coupler body having an interior passageway for receiving the duct therein. The coupler body has a generally U-shaped channel formed at one end thereof. The coupler element has a connector element formed on interior thereof adjacent one end of the coupler body so as to allow the coupler element to receive a variety of implements for the formation of the precast concrete segment.
U.S. Pat. No. 6,874,821, issued on Apr. 5, 2005 to the present inventor, describes a coupler apparatus for use with angled post-tension cables in precast concrete segmental construction. This coupler apparatus has a first duct, a first coupler member extending over and around the first duct, a second duct, a second coupler member extending over and around the second duct and a gasket received at the ends of the first and second coupler members so as to prevent liquid from passing between the coupler members into an interior of either of the ducts. The ducts extend at a non-transverse acute angle with respect to the ends of the coupler members. Heat shrink seals are affixed to the opposite ends of the coupler member so as to secure the coupler members to the ducts in liquid-tight relationship. The ends of the coupler member have generally V-shaped grooves facing each other. The gasket is received in compressive relationship within the V-shaped grooves.
U.S. Pat. No. 7,273,238, issued on Sep. 25, 2007 to the present inventor, teaches a duct coupler apparatus with compressible seals. This apparatus is used for joining the ends of a pair of ribbed ducts together. The apparatus has a collar with an interior suitable for receiving the ends of the pair of ducts therein. A first coupler element is translatably secured adjacent a first end of the collar. A compressible seal is disposed between a surface of the first coupler element and the first end of the collar. A second coupler element is secured adjacent a second end of the collar. A second seal is disposed between a surface of the second coupler element and the second end of the collar. The coupler elements are translatable so as to compress the seal such that a surface of the seal will bear against a respective rib of the pair of ducts.
U.S. Pat. No. 7,267,375, issued on Sep. 11, 2007 to the present inventor, describes a duct coupler apparatus. This apparatus is for joining ends of a pair of ducts together in end-to-end relationship. The apparatus has a collar with a first end portion and a second end portion. A first coupler element is translatably secured to an exterior of the collar for moving the first end portion between first and second positions. A second coupler element is translatably secured to the exterior of the collar so as to move the second end portion between first and second positions. The end portions have a plurality of fingers that are movable so as to be free of the surfaces of the duct when in the first position and which contact a rib of the duct when in the second position. The collar and the coupler elements form a liquid-tight seal over the respective ends of the pair of ducts.
FIGS. 1-3 herein describe the prior art coupler apparatus similar to that disclosed in U.S. Pat. No. 7,267,375. Referring to FIG. 1 , there is shown the coupler apparatus 10 in of the prior art. The coupler apparatus 10 includes a collar 12 , a first coupler element 14 and a second coupler element 16 . A first duct 18 is received within the interior of the collar 12 and within the interior of the first coupler element 14 . A second duct 20 is received within the collar 12 and within the interior of the second coupler element 16 . The collar 12 has an interior suitable for receiving the ducts 18 and 20 in end-to-end relationship and in generally longitudinal alignment. The collar 12 has first end portion 22 at one end thereof and a second end portion 24 at an opposite end thereof. Each of the end portions 22 and 24 are movable between a first position (illustrated by end portion 24 ) spaced away from the interior of the collar 12 and a second position (illustrated by end portion 22 ) which extends toward the interior of the collar 12 . The first coupler element 14 is translatably secured to the exterior of the collar 12 . The first coupler element 14 is translatable so as to move the first end portion 22 between the first and second positions. The second coupler element 16 is also translatably secured to the exterior of the collar 12 . The second coupler element 16 is translatable so as to move the second end portion 24 between the first and second positions.
As can be seen in FIG. 1 , the first duct 18 has a plurality of ribs 26 formed thereon. Longitudinal channels 28 extend between the ribs 26 and allow liquid and grout therein to communicate between the ribs 26 . Longitudinal channels 28 have an outer edge which is flush with the outer diameter of the respective ribs 26 . The first duct 18 has an outer wall which extends between the ribs 26 and defines the interior of the duct 18 . The second duct 20 similarly has a plurality of ribs 32 , longitudinal channels 34 and wall 36 . The first duct 18 is identical to the second duct 20 . In normal use, the ducts 18 and 20 will receive tendons therein and allow a grout material to fill the interior thereof. The respective channels 28 and 34 allow grout to fill the interior of the respective ducts 18 and 20 and to flow into the ribs 26 and 32 , respectively.
As can be seen, the first end portion 22 has a plurality of finger elements 38 , 40 , 42 , 44 and 46 extending outwardly therefrom. In FIG. 1 , for the purposes of illustration, the finger element 38 is illustrated in its second position which serves to lock the first duct 18 in its proper position. The finger element 22 has a lower surface 48 which will reside in surface-to-surface relationship with the wall 30 of duct 18 . An extension element 50 extends outwardly as a tip from the finger element 38 so as to reside over the outer surface of the rib 26 . An inclined surface extends between the tip 50 and the surface 48 so as to reside against the slanted surface of the rib 26 . The remaining finger elements 40 , 42 , 44 and 46 are illustrated in the first position extending away from the surface of the duct. In normal use, the finger elements 38 , 40 , 42 , 44 and 46 will move cooperatively relative to the translation of the first coupler element 14 on the collar 12 .
The collar 12 has a plurality of finger elements 52 , 54 , 58 , and 60 extending outwardly from an opposite end thereof of finger elements 22 . Each of the finger elements 52 , 54 , 58 , and 60 is illustrated in the first position spaced away from the exterior surface of the duct 20 . The coupler element 16 is translatable relative to the collar 12 so as to move the finger elements 52 , 54 , 58 , and 60 to the second position.
In FIG. 1 , it can be seen that there is an indented portion 62 formed in the collar 12 generally between the ends of the ducts 18 and 20 . The indented surface 62 will have an interior surface aligned with interior surface of the respective ducts 18 and 20 .
The collar 14 is translatable about one end of the collar 12 . The translating motion in the preferred embodiment of the present invention is established by a threaded relationship between the exterior surface of the collar 12 and the interior surface of the coupler 14 . In other embodiments of the present invention, the coupler element 14 is translatable by slidable or ratcheting motion. Suitable hinging mechanisms or other cantilever or lever actions can be incorporated within the apparatus 10 so as to facilitate proper translatable motion of the coupler elements 14 and 16 on the collar 12 . Coupler element 16 will have a configuration similar to that of coupler element 14 and will translate in the same manner as coupler element 14 . Each of the coupler elements 14 and 16 has a plurality of ribs 64 formed on an exterior surface thereof. Each of the plurality of ribs 64 extends longitudinally for at least a portion of the length of the respective coupler elements 14 and 16 . The plurality of ribs are radially spaced from each other around the diameter of the respective coupler elements 14 and 16 . Ribs 64 facilitate the ability of a worker to grasp the exterior surface of the coupler elements 14 and 16 and to provide the necessary translatable motion with respect to the movement of the coupler elements 14 and 16 onto the respective end portions 22 and 24 .
FIG. 2 illustrates the collar 12 as having the end portions 22 and 24 in the first position away from the respective ducts 18 and 20 . In FIG. 2 , the collar 12 is illustrated as having the indented portion 62 formed between the respective ends 66 and 68 of ducts 18 and 20 . The inward surface of the indented portion 62 is in coplanar alignment with the inner surface 70 of duct 18 and inner surface 72 of duct 20 . The collar 62 has an annular seal 74 extending around the interior of the collar 12 . A second annular seal 76 is also affixed to the collar 12 and extends around the interior of the collar 12 . The annular seals 74 and 76 can be formed of a suitable elastomeric material such that the seal 74 establishes a liquid-tight relationship with the rib 26 of duct 18 . The annular seal 76 will establish a liquid-tight seal with the rib 32 of duct 20 . It can be seen that the collar 12 has an inner surface which will generally abut the tops of the respective shoulders 26 and 32 of the ducts 18 and 20 . As such, the ducts 18 and 20 can be easily installed within the interior of the collar 12 by slidably inserting the ends 66 and 68 of ducts 18 and 20 into opposite ends of the collar 62 .
In FIG. 2 , it can be seen that the collar 12 has a threaded exterior surface 78 . The collar 12 also has another threaded exterior surface 80 formed thereon. The end portion 22 is integrally formed with the collar 12 at one end of the collar 12 . The second end position 24 is also integrally formed with the collar 12 at the opposite end of the collar 12 . The threaded portions 78 and 80 are respectively interposed between the indented portion 62 and the end portions 22 and 24 . The end portion 22 has a shoulder 82 formed thereon. The end portion 24 also has a shoulder 84 formed thereon. Underlying surface 48 extends from shoulder 82 outwardly therefrom. Another underlying surface 86 is formed on the end portion 24 and extends outwardly from the shoulder 84 . End surfaces 48 and 86 will extend generally upwardly at an acute angle with respect to a longitudinal axis of the collar 12 . In FIG. 2 , the first position of the end portions 22 and 24 is particularly illustrated. As such, the shoulders 82 and 84 , along with the surfaces 48 and 86 , will be generally spaced away from the respective ducts 18 and 20 so as to allow for the free insertion of the ends 66 and 68 of ducts 18 and 20 into the collar 12 .
The first coupler element 14 is illustrated as having interior threads 88 engaged with the exterior threads 78 of the collar 12 . The first coupler element 14 has an abutment end 90 extending into contact with a surface of the end portion. Similarly, the second coupler element 16 has an interior threaded section 92 threadedly engaged with the exterior threads 80 of the collar 12 . An abutment end 94 is formed on the coupler element 16 so as to reside against the surface of the end portion 24 .
FIG. 3 illustrates how the coupler elements 14 and 16 translate so as to move the end portions 22 and 24 into their second or locking positions. In normal use, the coupler elements 14 and 16 will be rotated so that the interior threads 88 will translate along the exterior threads 78 at one end of the collar 12 . The second coupler element 16 will similarly have its interior threads 92 rotate with respect to the exterior threads 80 . This causes the abutment end 90 of coupler element 14 to urge against the surface of the end portion 22 and to move the end portion 22 downwardly. As a result, the shoulder 82 will reside in contact (illustrated in broken line fashion) against a surface of rib 26 . The second coupler element 16 will work in a similar manner so that the shoulder 84 will reside in contact against a surface of the rib 32 . In this locked position, it will be impossible to pull the first duct 18 away from the second duct 20 . A secure seal is formed between the interior surfaces of the collar 12 and the exterior surfaces of the ducts 18 and 20 . The annular seal 74 and 76 will further provide a strong liquid-tight seal against the outer surfaces of the respective ducts 18 and 20 .
It has been found with the prior art coupler apparatus illustrated in FIGS. 1-3 that it is often somewhat complicated to properly install the apparatus. In certain circumstances, the installation can be somewhat time consuming. As such, it has been found that there is a need to provide a coupler apparatus for ducts which allows workman at the construction site to easily connect the ends of the ducts through a use of a coupler. The coupler should be of a type that is suitable for effectively engaging the ends of the ducts in a liquid-tight manner. The coupler apparatus should have a minimum number of moving parts so as to effectively create the necessary seal while, at the same time, avoids complexities in the actual manufacturing injection molding of such a coupler apparatus.
It is an object of the present invention to provide a duct coupling system that allows the ends of tendon-receiving ducts to be joined in a proper end-to-end relationship.
It is another object the present invention to provide a duct coupling system that effectively establishes a liquid-tight seal between the respective coupled ducts.
It is another object of the present invention to provide a duct coupling system which allows the coupler to be formed through an injection molding process.
It is still another object of the present invention to provide a duct coupling system which allows the ducts to be effectively coupled in a minimal amount of time with a minimum complexity.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.
BRIEF SUMMARY OF THE INVENTION
The present invention is a duct coupling system that comprises a first duct, a second duct, and a coupler that joins the first duct to the second duct. The first duct has an interior passageway at a first end. The first end has threads thereon. The interior passageway opens at the first end of the first duct. The second duct also has an interior passageway at a first end. The interior passageway of the second duct opens at the first end of the second duct. The first end of the second duct has threads thereon. The coupler is a generally tubular body with a first end and a second end and an interior passageway extending therebetween. The first end of the tubular body is threadedly engaged with the threads of the first end of the first duct. The second end of the coupler is threadedly engaged with the threads at the first end of the second duct.
The interior passageway of the first duct and the interior passageway of the second duct and the interior passageway of the coupler are axially aligned.
The thread of the duct has a unique configuration. The thread of the first end of the first duct has a narrow width portion and a wide width portion. This thread extends radially outwardly of the first duct for a lesser distance at the narrow width portion than a distance at the wide width portion. The narrow width portion of this thread is spaced from the narrow width portion of an adjacent thread. The wide width portion is offset by approximately 90° from the narrow width portion.
Each of the first and second ducts has a ridge extending circumferentially therearound adjacent the first end thereof. The coupler has a first lip extending longitudinally outwardly therefrom so as to overlie the ridge of the first duct. The coupler having a second lip extending longitudinally outwardly therefrom so as to overlie the ridge of the second duct. The body of the coupler has a first ring seal juxtaposed between an inner surface of the body and a surface of the ridge of the first duct. The body of the coupler also has a second ring seal juxtaposed between another inner surface of the body and surface of the ridge of the second duct. The body of the coupler has a radially indented area extending circumferentially therearound between the first and second ends of the coupler. This radially indented area is positioned between the first end of the first duct and the first end of the second duct. The first end of the body of the coupler has a square threads extending inwardly therefrom and engaged with the threads at the first end of the first duct. The second end of the body of the coupler has square threads extending inwardly therefrom and engaged with the threads at the first end of the second duct. The thread at the first end of the first duct has an end and a portion circumferentially spaced from this end of the thread. The end of the thread extends radially outwardly of the first duct for a lesser distance than a distance that the portion extends outwardly of the first duct. The first end of the body of the coupler is slidable over the ends of the thread. The coupler is rotatable relative to the first duct so that the threads at the first end of the body of the coupler engaged with the portion of the threads at the first end of the first duct.
In the present invention, each of the first duct and the second duct and the coupler are integrally formed of a polymeric material. A plurality of tendons extend through the interior passageways of the first duct, the second duct, and the coupler.
The present invention is also a duct coupler that includes a generally tubular body having a first end and a second end with interior passageway extending therebetween. The first end and the second end are interiorly threaded. The body is formed of a polymeric material. The threads at the first end and the threads at the second end of the body are square threads. The body has an outer surface with a first lip extending longitudinally outwardly at the first end and a second lip extending outwardly at the second end. A first ring seal is affixed against an inner surface of the body adjacent the first lip. A second ring seal affixed against an inner surface of the body adjacent the second lip. The body has a radially indented area around a circumference thereof in an area between said first and second ends.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a side elevational view of a prior art duct coupler.
FIG. 2 is a cross-sectional view showing the end portions of the collar of the coupler apparatus of the prior art in a first position.
FIG. 3 is a cross-sectional view showing the end portions of the collar of the coupler of the prior art in the second locked position.
FIG. 4 is a cross-sectional view showing the duct coupling system in accordance with the preferred embodiment of the present invention.
FIG. 5 is a cross-sectional view showing the duct coupling system of the present invention with the coupler rotated 90° with respect to the duct.
FIG. 6 is a upper perspective view of an end of either the first duct and a second duct as used with the coupler apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 4 , there is a shown the duct coupling system 100 in accordance the preferred embodiment of the present invention. The duct coupling system 100 includes a first duct 102 , a second duct 104 and a coupler 106 . Coupler 106 joins the ducts 102 and 104 in a liquid-tight relationship.
The first duct has an interior passageway 108 and a first end 110 . The interior passageway 108 opens at the first end 110 . The first end 110 has threads 112 formed thereon. The second duct 104 has an interior passageway 114 and a first end 116 . The interior passageway 114 of the second duct 104 opens at the first end 116 . The first end 116 of the second duct 104 has threads 118 formed thereon.
The coupler 106 has a generally tubular body 120 . The tubular body 120 has a first end 122 and a second end 124 . The coupler 106 also has an interior passageway 125 extending between the first end 122 an the second end 124 . It can be seen that the first end 122 of the body 120 is threadedly engaged with the threads 112 at the first end 110 of the first duct 102 . The second end 124 of the coupler 106 is threadedly engaged with the threads 118 at the first end 116 of the second duct 104 .
The interior passageway 108 of the first duct 102 and the interior passageway 114 of the second duct 104 and the interior passageway 125 of the coupler 106 are longitudinally axially aligned.
In FIG. 4 , it can be seen that the first duct 102 has a ridge 130 extending circumferentially therearound adjacent to the first end 110 thereof. The coupler 106 has a first lip 132 extending longitudinally outwardly therefrom so as to overlie the ridge 130 of the first duct 102 . The coupler 106 also has a second lip 134 extending longitudinally outwardly therefrom so as to overlie the ridge 136 of the second duct 104 . It can be seen that there is a first elastomeric ring seal 138 juxtaposed between an inner surface of the body 120 of the coupler 106 and a surface of the ridge 130 of the first duct 102 . A second elastomeric ring seal 140 is juxtaposed between another inner surface of the body 120 of the coupler 106 and a surface of the ridge 136 of the second duct 104 .
The coupler 106 has a radially indented area 142 extending circumferentially therearound between the first end 122 and the second end 124 of the coupler 106 . This radially indented area 142 is positioned between the first end 110 of the first duct 102 and the first end 116 of the second duct 104 .
In FIG. 4 , it can be seen that the first end 122 of the body 120 has square threads 150 extending inwardly therefrom and engaged with the threads 112 at the first end 110 of the first duct 102 . The second end 124 of the body 120 of coupler 106 also has square threads 152 that are engaged with the threads 118 at the first end 116 of the second duct 104 .
FIG. 5 shows another form of the present invention in which the coupler 106 is illustrated as being located in another position with respect to the threads of the respective ducts 200 and 202 . It can be seen in FIG. 5 that the first elastomeric ring seal 204 that juxtaposed against an inner surface of the lip 206 at the end of coupler 106 and an outer surface of the first duct 200 . There is also another elastomeric ring seal 208 that is juxtaposed in liquid-tight relationship between the end 210 of the coupler 106 and an outer surface of the duct 202 . In this embodiment, the lips at the end of the coupler 106 do not overlie the ridge 220 of the first duct 200 and the ridge 222 of the second duct 202 .
FIG. 6 shows the ends of the respective ducts. In particular, duct 104 is particularly illustrated in FIG. 6 . The unique configuration of the threads 118 adjacent to the end 116 of the duct 104 are particularly illustrated. The duct 104 is illustrated as having interior passageway 114 opening at the end 116 and extending therethrough. The duct 104 is also illustrated as having the ridge 136 extending circumferentially therearound and forming a raised surface with respect the to threads 118 .
In particular, in FIG. 6 , it can be seen that there is illustrated a single thread 300 . The threads 300 includes a narrow width portion 302 and a wide width portion 304 . The narrow width portion 302 is of set by approximately 90° from the wide width portion 304 . In the preferred embodiment of the present invention, the narrow width portion 302 extends outwardly of the surface 306 of the duct 104 for a distance less than the distance that the wide width portion 304 extends outwardly from surface 306 . The narrow width portion 302 is in spaced relationship to another narrow width portion 310 of an adjacent thread. The narrow width portion 310 of the adjacent thread 312 extends pass the end of the thread 300 . The alignment of the various narrow width portions of the various thread 300 will serve to allow the teeth of the duct coupler to be slidably positioned thereover. To install the duct, it is only necessary to push the threaded portion of the coupler over the narrow width portion so that the end of the coupler abuts the ridge 136 . The coupler can then be rotated upwardly or downwardly such that the threads become wedged between the wide width portion 304 of the various threads 300 . As such, a 90° rotation of the coupler in one direction or another will cause the coupler to be installed effectively in a liquid-tight sealing manner. As such, installation in the coupler can be accomplished in a very efficient and effective manner. If it is desired to remove the coupler for any reason, it is only necessary to rotate the coupler backward by 90° so that the threads can slide over the narrow width portions of the duct 104 . A similar operation can be used so as to install the coupler over the respective threads of the first duct 102 .
In the present invention, the coupler is able to establish a liquid-tight seal in a fast and efficient manner. Additionally, the coupler can be formed through an injection molding process. It is only necessary to form the threads on the inner surface of the coupler. The lips of the coupler will extend outwardly so as to effectively center the coupler with respect to ridges formed on the ducts. As such, a proper alignment of the couplers with the duct is effectively achieved. The liquid-tight sealing relationship is established by virtue of the rotation of the coupler with respect to the ducts.
The foregoing description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.
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A duct coupling system has a first duct with and end having a threads thereon, a second duct having an end with threads thereon, and a coupler having a first end threadedly engaged with the threads of the first duct and a second end threadedly engaged with the threads of the second duct. The ducts and the coupler are each integrally formed of a polymeric material. A plurality of tendons extend through the interior passageways of the ducts of the coupler.
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This application claims the benefit of U.S. Provisional Appln. No. 60/440,330, filed Jan. 16, 2003.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a machine shoe for the support of objects, such as apparatuses and machines, with a movable metallic spindle secured to a base consisting of a bottom made of polymer material, such as a rubber product, with a metallic upper part. The invention moreover relates to method of supporting objects, such as apparatuses and machines.
2. The Prior Art
Danish Utility Model DK 93 00256 discloses a machine shoe with a concealed attachment of the spindle, which is mounted on the object to be supported, in the lower base of the machine shoe.
In many applications where machine shoes are used, there are great requirements with respect to hygiene. This applied to, e.g., the food and hospital sectors.
The concealed attachment of the spindle and base part of the machine shoe is therefore of great importance to the hygiene, as the completely closed bottom prevents impurities and bacteria from penetrating up into the machine shoe from, e.g., a floor or tile level on which the machine shoe is placed.
The machine shoe as described in the Danish utility model, however, has the drawback that the spindle is secured to the base of the machine shoe in a manner which just permits a very small movement of the spindle relative to the lower part of the support. This means that requirements must be made with respect to the face on which the machine shoe is placed, as it must be almost plane and parallel with the bottom face of the machine shoe in order for the machine shoe to support with the entire bottom face.
Machine shoes are known where the spindle part can be moved better relative to the lower part of the machine shoe. One type of these is characterized in that the spindle stands on the lower part of the machine shoe without being secured to the bottom part. This, however, creates problems in situations where the object supported by the machine shoe is to be moved, since, in that case, the machine shoe parts fall apart. In other types, the spindle in a lower ball head is secured to the lower part of the machine shoe, but it is problematic for both types that impurities may accumulate in the joints of the machine shoe.
In other known machine shoe types, the spindle may also be moved relative to the lower part of the machine shoe, while the spindle is secured to the base of the machine shoe. These machine shoe types are characterized in that the spindle is secured to the base of the machine shoe by assembly through an opening in the bottom of the machine shoe, frequently by screwing a nut on the lower end of the spindle. These structures, however, have the drawback that, e.g., impurities and bacteria may accumulate in the hole in the bottom of the machine shoe, which per se constitutes a hygiene problem. Further, certain structures involve the risk that impurities and bacteria from the opening in the bottom of the machine shoe can penetrate up through the machine shoe and from there to the object which is to be supported.
Accordingly, an object of the invention is to improve the known machine shoe structure of the type where the spindle may be moved relative to the base, and so that accumulation of impurities is eliminated.
SUMMARY OF THE INVENTION
The object of the invention is achieved by a support apparatus having a movable spindle mounted to a base which is characterized in that the attachment of the spindle in the base is concealed, and that the surface of the base is shaped as part of a ball face.
Hereby, the bottom face of the machine shoe may remain uninterrupted, thereby preventing impurities and bacteria from accumulating in the machine shoe, thus eliminating the risk that impurities and bacteria from the bottom can penetrate up through the machine shape and spread to the object which is supported.
The, invention is moreover characterized in that at least two locking rings for the attachment of a spindle are integrated in the polymer part of the base. This provides the advantage that the relation ship between the force by which the spindle is attached to the base of the machine shoe and the volume of the base is optimized.
A further feature of the invention is that the locking rings integrated in the base are positioned in parallel and with the same centre axis, so that the centre point between the centre hole of the locking rings coincides with the centre of the movement of a spindle which is held by the locking rings, whereby the spindle may be moved optimally as it is attached at its pivot point.
The invention is also characterized in that the upper face of the base, in the direction from which a secured spindle extends, is shaped as part of a ball face with the centre in the centre point between the centre holes of the integrated locking rings, thereby ensuring that the spindle may be moved freely in all directions solely restricted by the ball face.
As mentioned, the invention also relates to a method which is characterized in that one or more components are used for the support, which allows optimum hygiene in supports based on machine shoes.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained more fully with reference to the drawings, in which
FIG. 1 is a cross-sectional view of a support where the spindle is arranged vertically relative to the lower base;
FIG. 2 is a cross sectional view of a support where the spindle has been pivoted relative to the lower base;
FIG. 3 is a cross sectional view of a support where two locking rings are integrated in the polymer part of the base, and illustrates that the top of the base is a part of a ball face; and
FIG. 4 shows the same cross-section as FIG. 3 , but with the solid angle boundary of the ball face drawn.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a cross-section of a support where a spindle 1 extends from a base 2 . The support is shown in section through an axis of symmetry 9 . The spindle 1 is provided with threads 3 for attachment in the object which is to be supported. The spindle 1 is moreover provided with a notch in the form of a spanner face which is used for the tightening of the spindle to the object to be supported, and for level adjustment. The spindle 1 will typically be made of stainless steel.
The base 2 of the support consists of a basic material 7 which is a polymer, such as rubber, provided by a moulding, gluing or vulcanization process with a metallic surface part 8 , which will typically be made of stainless steel.
The spindle 1 is introduced into the base 2 through an opening in the top of the base 2 and attached concealed by inserting the end 5 into two locking rings 6 shown. Tests have shown that two locking rings provide a sufficient attachment force between the base 2 and the spindle 1 , while the extent of the diameter of the locking rings 6 is minimized, thereby allowing the top of the base 2 to be shaped as a part of a ball face having a minimal ball diameter.
FIG. 1 moreover shows that in the contact face contacting the top of the base 2 the spindle 1 is configured complementarily with the ball surface of the base, so that spindle and base are adapted completely to each other, which counteracts reception of impurities between the two support components. As will also appear from FIG. 1 , the spindle 1 is made of an uninterrupted piece of material, so that no impurities can accumulate through joints or the like.
FIG. 2 shows a support in the same section as FIG. 1 , where the spindle 1 is pivoted through an angle 10 relative to the base 2 . Pivoting of the spindle takes place with the centre at point 11 , which is also the centre point of the two locking rings 6 .
In FIG. 2 , the spindle 1 has been pivoted to an outer angle limited by the opening in the base 2 . It moreover appears from FIG. 2 that the spindle 1 is configured such that it covers the opening in the top of the base 2 also at the extreme points for its movement. This means that the spindle 1 can be moved freely in all directions within the given boundaries without any possibility of penetration and accumulation of impurities in the structure.
FIG. 3 shows the base 2 of the support in a section through the axis of symmetry 9 . The base consists of the shown basic material 7 , which is a polymer e.g. a rubber mixture having an opening at the top through which a spindle may be inserted into and be attached in the integrated locking rings 6 A and 6 B of the polymer material. The locking rings will normally be embedded in the polymer material.
The point 11 , which is the centre point for the two shown locking rings 6 A and 6 B, is also the centre for the movement of a spindle which is attached by insertion into the locking rings.
The upper part of the base 2 is provided with a metallic surface part 8 , which is typically a stainless steel alloy, as well as a polymer part 13 which terminates in an opening for the mounting of a spindle.
As shown in FIG. 3 , the opening at the top consists of a cylindrical part 14 , which is characterized by having a smaller diameter than the diameter of the spindle, which is surrounded by the polymer part face 14 after insertion. When the diameter of the polymer is smaller than the diameter of the spindle, it is ensured that the junction between the polymer and the spindle is very tight, which is important when requirements are made with respect to hygiene.
It moreover appears from FIG. 3 that the opening in the polymer 7 from the cylindrical portion 14 in a direction toward the locking rings 6 A and 6 B changes its shape so that the diameter increases over a portion 15 and then again changes its direction so that the inner diameter of the opening again diminishes over a portion 16 . When a spindle is inserted into the opening in the polymer and is attached in the locking rings 6 A and 6 B, the shape of the polymer shown in FIG. 3 at the subportions indicated at 15 and 16 will provide a cavity between the attached spindle and the polymer 7 , as the spindle is cylindrical in the area around the faces 15 and 16 .
The cavity between the polymer and the spindle caused by the faces 15 and 16 serves the function of allowing an attached spindle to move without compressing and thereby potentially damaging the polymer 7 .
The configuration of the faces 15 and 16 also means that a spindle attached in the locking rings may be moved, while maintaining the sealing of the face 14 against the spindle, as the cavity below the face 14 ensures that no polymer material is pressed up from below by the spindle movement, which might result in an opening between spindle and polymer, involving the risk of penetration of impurities.
FIG. 4 shows the base of a support in a section in the axis of symmetry 9 , where the ball-shaped part of the top of the base is indicated at an angle 18 . The ball segment has its centre at the point 11 , which is also the centre point for the two locking rings 6 . The radius of the ball surface is shown at 17 .
The use of the two locking rings 6 provides an attachment force for a spindle inserted into the locking rings which corresponds to the force that could be achieved with just one locking ring with a larger diameter.
However, the problem is that if the locking ring diameter is increased, this would require that also the ball surface radius is to be increased, as tests have shown that a certain amount of polymer material must be present between the locking rings 6 and the metallic surface part 8 for the object to be manufactured and operate expediently.
In this connection, it is evident that increased requirements with respect to the radius of the ball face means that the support becomes physically larger, which is undesirable for several reasons, including considerations of space, and a larger machine shoe will also require a greater consumption of material, which will make the machine shoe more expensive to manufacture and thereby less competitive.
Precisely two locking rings have been found to give an optimum relation between easy production, functionality and size of the machine shoe.
In practice, expedient embodiments of the ball segment surface of the support may have a solid angle which, with the centre at 11 , will have a mean value of about 4.5 steradians with outer limit values that will be in the range between 2.5 and 6.0 steradians.
As will moreover appear from FIG. 4 , it is characteristic of the base part 2 of the support that the metallic surface part, forming at the top of the base a part of a ball face as indicated at the angle 18 where the ball face shape terminates, convexly changes its shape so that the metallic surface in a portion 19 forms part of a truncated cone having the smallest radius at the ball face part and the largest radius toward the bottom of the base.
It is essential in this connection that the surface, as shown at 19 , is inclined from the centre of the base toward the rim of the base, whereby impurities will slide off the face, which in turn is important in terms of hygiene.
Although the invention has been explained in connection with a support for e.g. machines and a method for support, nothing prevents the principles of the invention from being used in other connections within the scope defined by the claims.
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A machine shoe and a method for the support of objects, such as apparatuses and machines, characterized by being tolerant to irregularities in the surface on which the object to be supported is placed. The machine shoe has a movable spindle which is secured in concealed fashion in a base by insertion into two locking rings integrated in a polymer material of a lower part of the base. The centre point between the locking rings forms the centre for the movements of the spindle.
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BACKGROUND OF THE INVENTION
Although many apparatuses for board games have been developed, none of them can lead to satisfactory results because the playing pieces such as chessmen or the like and the board are placed separately thereby causing much inconvenience. Moreover, such an apparatus for board game merely provides a kind of board game and only allows two persons to play at the same time.
Thus, the inventor of the present invention has contrived to design an improved chess box to mitigate such inconvenience.
SUMMARY
It is a primary object of the present invention to provide a novel chess box which may obviate the above-mentioned drawbacks.
It is another object of the present invention to provide a novel chess box which may offer various kinds of board games.
It is still another object of the present invention to provide a novel chess box which is convenient to carry.
It is still another object of the present invention to provide a novel chess box which is simple in structure.
It is still another object of the present invention to provide a novel chess box which is easy to produce.
It is still another object of the present invention to provide a novel chess box which is economic to produce.
It is a further object of the present invention to provide a novel chess box which is attractive in appearance.
Other objects and merits and a fuller understanding of the present invention will be obtained by those having ordinary skill in the art when the following detailed description of the best mode contemplated for practicing the invention has been read in conjunction with the accompanying drawings wherein like numerals refer to like or similar parts and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the interior of a novel chess box embodying the present invention;
FIG. 2 is a top view of the novel chess box with its lid opened and two containers closed;
FIG. 3 shows the novel chess box with a positioning plate mounted thereon;
FIG. 4 shows six boards for different kinds of board grames;
FIG. 5 is a perspective view of the novel chess box in the state of the closing;
FIG. 6 is a bottom view of the novel chess box; and
FIG. 7 shows an application of the novel chess board.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings and in particular to FIG. 1 thereof, the novel chess box according to the present invention comprises a main body portion (2) on which is rotatably mounted a lid (1) by a hinge (21) such that the lid (1) may rotate about the hinge (21) in the directions as indicated by arrow (31).
At the center of the main body portion (2) is fixedly attached a magnet (22). The main body portion (2) is further provided with positioning edges (23) at two sides and two pins (24) at two diagonal corners. Two containers (43) each provided with a sheet iron (46) at its bottom and divided into two compartments (43) and (42) by a partition (41) are pivoted on the main body portion (2) by the two pins (24) respectively, enabling each of the containers (4) to be rotated about its corresponding pin (24) in the directions as indicated by arrow (32). Each of the container (4) is equipped with a sheet iron (44) which is designed so that when the containers (4) are turned into the main body portion (2), the sheet iron (4) will be in contact with the magnet (22). Accordingly, the containers (4) will not be opened unintentionally. It is noted that the playing pieces (the chessmen or the like) of the present invention are provided with a magnet so that they can be retained into the containers (4) and will not be moved out of the containers (4) accidentally.
Turning to FIG. 3, on the main body portion (2) is mounted a positioning plate (5) having two positioning edges (51) which, when cooperated with edges (23) of the main body portion (2), will form a closed recess on which boards (6) shown in FIG. 4 and the specifications (not shown) of board games may be placed.
To close the novel chess box according to the present invention, first turn the two containers (4) into the main body portion (2) so that the sheet iron (44) of each container (4) will be in contact with the magnet (22). Place the positioning plate (5) on the main body portion (2) in the way such that its two positioning edges (51) will cooperate with the edges (23) of the main body portion (2) to form a closed recess. Put the boards (6) and the specifications (not shown) on the positioning plate (5). Then, engage slot (11) of the lid (1) with hook-like connector (25) of the main body portion (2) to close the novel chess box according to the present invention. As shown in FIG. 1, a recess (25) is provided under the hook-like connector (25) so as to facilitate the opening of the novel chess box.
With reference to FIGS. 1 and 5, the lid (1) and the main body portion (2) are provided with two slots (12) and (27) which will form a handle when the novel chess box is closed. On the top of the lid (1) there is a recess for receiving one of the boards (6). The recess is provided with a magnet (13) at each corner such that the board (6) which is made of sheet iron may be firmly attached on the top of the lid (1). Further, a notch (14) is provided on the edge of the lid (1) so as to facilitate the removing of the board (6) on the lid (1).
With reference to FIG. 6, there is shown a bottom view of the novel chess box according to the present invention. As illustrated, each of the containers (4) is provided with a cavity (45) by means of which the containers (4) may be pulled out easily.
In use, first open the novel chess box. Take out a desired board (6). Pull out the containers (4). Put down the lid (1) on the main body portion (2). Then, place the desired board on the top of the lid (1). The captured playing pieces (chessmen or the like) may be conveniently put into the compartments (42) of the containers (4) while the compartments (43) of the container (4) are served for receiving the playing pieces (chessmen or the like) to be set out on the board.
After use, first put the playing pieces (chessmen or the like) into the compartments (43) of the containers (4). Remove the board (6) from the top of the lid (1) via the cavity (14). Open the lid (1). Place the board (6) into the positioning plate (5). Close the lid (1) and then push the containers (4) into the main body portion (2).
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 only and that numerous changes in the detail of construction and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.
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A novel chess box comprising a main body portion having a magnet at its center, a lid hinged on the main body portion, a pair of containers each pivoted on the main body portion and provided with a sheet iron, a positioning plate removably mounted on the main body portion, a number of boards for various kinds of board games, and a plurality of playing pieces for playing with the board games.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of, claims priority to and the benefit of, U.S. Ser. No. 15/166,673, filed May 27, 2016 entitled “SYSTEMS, METHODS, AND COMPUTER PROGRAM PRODUCTS FOR ADAPTING THE SECURITY MEASURES OF A COMMUNICATION NETWORK BASED ON FEEDBACK.” The '673 application is a continuation of U.S. patent application Ser. No. 14/252,276, filed Apr. 14, 2014, now U.S. Pat. No. 9,378,375 which is a continuation of U.S. patent application Ser. No. 12/504,828, filed Jul. 17, 2009, now U.S. Pat. No. 8,752,142. The foregoing applications are hereby incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention generally relates to information security systems, and more particularly, to systems, methods, and computer program products for adapting security measures of a communication network based on dynamic feedback.
Related Art
With the proliferation of mobile communication devices, such as mobile telephones, financial account holders that have such devices have begun to use them to complete financial transactions. Enabling financial account holders to do so, however, poses unique security risks for financial account issuers, particularly because security capabilities and risks vary widely across different mobile communication devices and different mobile communication networks. For example, typical payment systems involve point-of-sale (POS) terminals that are usually owned and designed by either financial transaction issuers or merchants. In contrast, because mobile communication devices are manufactured by various manufacturers and can be modified by third parties, financial account issuers have less control and knowledge of the security capabilities and risks associated with them. This makes it more difficult to control the security of financial transactions that are completed using mobile communication devices. Security measures vary based on particular models of mobile communication devices, thus compounding this inherent security risk.
The risk for financial account issuers is further complicated by the mobility of mobile communication devices. Each location in which mobile communication devices can be operated potentially has a different security environment. As a result, different security measures for each location are necessary. For example, bringing a mobile communication device into a foreign country may require the mobile communication device to roam on a foreign mobile communication network, which has inherently different security risks, capabilities, and other characteristics.
Security designers perform a labor-intensive and exhaustive analysis of the risks associated with each component of a new network in an attempt to safely interface their existing security system with the new network. The existing security system is often modified to accommodate the risks associated with the new network. This process takes a substantial amount of time and thus limits the speed with which financial account issuers can enter new markets that utilize mobile-based financial transaction networks. As a consequence, they can lose market share.
In addition, security designers typically assume that all security characteristics and risks of the network components will remain static once the system is deployed. A typical security system thus utilizes a particular set of security measures deployed until the security system is taken offline and either replaced or modified. In other words, if risks of the security system change, for example, by a breach of a security measure by an attacker, a maintenance window or an outage must be realized to enable the security system to be modified to respond to a security breach, patch, or upgrade. Such a system cannot adapt dynamically to various detected feedback relating to changes impacting the security situation of the network. Typical security systems, therefore, lack the adaptability necessary to be suitable for mobile-based financial transaction systems. Moreover, the static security measures of typical security systems increase the ease with which internal and external attackers can circumvent the security measures. As payment and network systems adapt to next generation payment and communication, the attacks and exploits will also evolve into next generation criminal exploits.
Notwithstanding the above-mentioned security risks, enabling mobile transactions is still a particularly attractive means for financial account issuers to enter the markets of non-bankable countries where widespread POS infrastructure is neither available nor practical.
Given the foregoing, it would be useful to be able to continuously detect changes in network security characteristics, and adapt based on these detected changes to maintain an acceptable level of security for existing and new network connections including merchants, customers, and partners for visiting and home networks.
It also would be useful to enable business entities, such as financial account issuers, to enter new markets (e.g., the mobile-based financial transaction market) with minimal modifications to their existing security system, and to accept new risk scenarios with the ability to manage magnitude of exposure by network segment, region, issuer, partner, device, and/or account across numerous device and network types.
In addition, it would be useful to enable the characterization of currently uncharacterized (e.g., non-domestic) communication network components and/or attributes to enable adaptation to the risks to maintain an acceptable level of security.
BRIEF DESCRIPTION OF THE INVENTION
The present invention meets the above-identified needs by providing systems, methods, and computer program products for adapting the security measures of a communication network based on dynamic feedback.
Trust mediator agents are associated with each network component. The trust mediator agents continuously detect changes in the security characteristics of each network component and feed the detected changes back to a trust mediator. The trust mediator uses the feedback from trust mediator agents to determine whether and how to modify the currently running security safeguards in order to maintain an appropriate level of security. If any modifications are necessary, the trust mediator communicates the modifications to the appropriate network component via the associated trust mediator agent for implementation. The process is recursive and thus continuously adapts to changes in network security characteristics as they arise over time to strike a balance between the probability of loss plus magnitude of loss versus acceptable risk to enable business transactions to continue without disruption at an account level and/or at a network component level.
A business entity (e.g., a financial account issuer) can integrate new communication networks having new security characteristics into their existing network without the need to perform an exhaustive and labor-intensive upfront analysis to estimate the security impact the new communication network will have on their existing network. Instead, the business entity can define rules, such as a threshold of acceptable risk, begin to communicate with the new network, and permit their existing security system to detect and adapt to the security characteristics of the new network while maintaining the acceptable risk acceptance level. Time-to-market is reduced, and the level of risk exposed to the business entity can be managed at minimized level.
Users' expectations regarding security measures are taken into account. Thus, if a particular security measure is too inconvenient for a user, the security measure is modified or disabled to a minimal level. The minimal level balances risk acceptance of a firm with convenience cost representing user or account holder countermeasure choice, and provides the issuer and the account holder with firm acceptable transaction risk elasticity. Alternatively, if the security measure provides too low a security level for the user to accept the security measure, it is modified or replaced with a more rigorous security measure. This increases propensity for user satisfaction and thus movement towards equilibrium of strategy and payoff for usage of the system based on time, location, and relevance, and results in more efficient risk models to increase market share for the business entity.
In one embodiment, a security system is dynamically adapted based on security goals, threats, and characteristics of a communication network. Trust mediator agents collect security-related data associated with communication network modules, the trust mediator agents being associated with the network modules, respectively. At least one of the communication network modules is a mobile communication device. The trust mediator agents transmit the security-related data to a trust mediator over the communication network. In turn, the trust mediator determines, based on at least one of the security-related data transmitted by the trust mediator agents and a predetermined rule stored in a memory, modifications to one or more security safeguards. The trust mediator transmits instructions corresponding to the modifications to at least one of the trust mediator agents over the communication network or changes a protection profile associated with the communication network module.
Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit of a reference number identifies the drawing in which the reference number first appears.
FIG. 1 is a diagram of an exemplary security system for adapting security measures of a communication network based on dynamic feedback, in accordance with an embodiment of the present invention.
FIG. 2 is a flowchart illustrating an exemplary process for adapting security measures of a communication network based on dynamic feedback in accordance with an embodiment of the present invention.
FIG. 3 is a block diagram of an exemplary computer system useful for implementing the present invention.
DETAILED DESCRIPTION
The present invention is directed to systems, methods and computer program products for adapting security measures of a communication network based on dynamic feedback, which are now described in more detail herein in terms of an example mobile payment system. This is for convenience only and is not intended to limit the application of the present invention. In fact, after reading the following description, it will be apparent to one skilled in the relevant art(s) how to implement the following invention in alternative embodiments (e.g., general network security systems, mass transit security systems, home and business security systems, etc.).
The terms “user,” “consumer,” “account holder,” and/or the plural form of these terms are used interchangeably throughout herein to refer to those persons or entities capable of accessing, using, being affected by and/or benefiting from the present invention.
A “merchant” as used herein refers to any person, entity, distributor system, software and/or hardware that is a provider, broker and/or any other entity in the distribution chain of goods or services. For example, a merchant can be a grocery store, a retail store, a travel agency, a service provider, an online merchant or the like.
A “transaction account” as used herein refers to an account associated with an open account or a closed account system. The transaction account can exist in a physical or non-physical embodiment. For example, a transaction account can be distributed in non-physical embodiments such as an account number, frequent-flyer account, telephone calling account or the like. Furthermore, a physical embodiment of a transaction account can be distributed as a financial instrument.
An “account,” “account number,” or “account code,” as used herein, can include any device, code, number, letter, symbol, digital certificate, smart chip, digital signal, analog signal, biometric or other identifier/indicia suitably configured to allow a consumer to access, interact with or communicate with a financial transaction system. The account number can optionally be located on or associated with any financial transaction instrument (e.g., a rewards, charge, credit, debit, prepaid, telephone, embossed, smart, magnetic stripe, bar code, transponder or radio frequency card).
The terms “financial account issuer,” “account issuer,” and “issuer,” and/or the plural forms of these terms are used interchangeably throughout herein to refer to those persons or entities that provide transaction account(s) to account holders. For example, an issuer may be a credit card issuer, a bank, or any other financial institution.
In general, transaction accounts can be used for transactions between the user and merchant through any suitable online or offline communication network, such as, for example, a wired network, a wireless network, a telephone network, an intranet, the global, public Internet, and/or the like. Additionally, the user can complete transactions with the merchant using any suitable communication device, such as a point-of-interaction device (e.g., a point-of-sale (POS) device, a personal digital assistant (PDA), a mobile telephone, a kiosk, etc.), a radio frequency enabled transaction card, and/or the like.
A financial transaction instrument (also referred to as a “payment device”) can be traditional plastic transaction cards, titanium-containing, or other metal-containing, transaction cards, clear and/or translucent transaction cards, foldable or otherwise unconventionally-sized transaction cards, radio-frequency enabled transaction cards, or other types of transaction cards, such as credit, charge, debit, pre-paid or stored-value cards, or any other like financial transaction instrument. A financial transaction instrument can also have electronic functionality provided by a network of electronic circuitry that is printed or otherwise incorporated onto or within the transaction instrument (and typically referred to as a “smart card”), or be a fob having a transponder and an RFID reader.
The term “safeguard,” “security measure,” “security safeguard,” and/or the plural forms of these terms are used interchangeably throughout herein to refer to any process, hardware, software, algorithm, countermeasure, or the like, that increases security, confidentiality, and/or integrity of data communicated over communication networks. For example, a safeguard can be a key length, an encryption/decryption algorithm, a checksum, a hash function, an access level, a password requirement, a fingerprint requirement, or the like.
FIG. 1 is a diagram of an exemplary security system 100 for adaptively securing mobile communication device transactions in accordance with an embodiment of the present invention. As shown in FIG. 1 , security system 100 includes both internal network components 118 and external network components 120 . Internal network components 118 are network components that are internal to an issuer network. External network components 120 are network components that are external to the issuer network.
External network components 120 include an external terminal 102 , which is any electronic communication device a consumer can use as an interface to complete a financial transaction with a merchant. For example, external terminal 102 can be a point-of-sale (POS) device, a kiosk, or a mobile communication device such as a mobile telephone, a personal computer, a POS device, a personal digital assistant (PDA), a portable computing device, a radio frequency enabled transaction card, or the like.
Another external network component 120 is a visiting network 110 , which is any electronic communication network that is communicatively coupled to external terminal 102 and one or more internal network components 118 . Example visiting networks 110 include a mobile telephone carrier network, an external payment network and/or service, a media network, a Rich Site Summary (RSS) feed network, a private network, a public network, a Bluetooth™ network, an automated clearing house (ACH) network, a peer-to-peer (P2P) network, or the like.
Internal network components 118 include a gateway 112 , which is communicatively coupled to visiting network 110 . External terminal 102 communicates with internal network components 118 through visiting network 110 . Gateway 112 translates communication network protocols to enable proper communication between visiting network 110 and internal network components 118 . Gateway 112 also includes any number of communication network modules depending on the characteristics of visiting network 110 and internal network components 118 . For instance, gateway 112 can include a firewall, a network address resolution table, a proxy for address translation, a session border controller, etc. (all not shown).
Another internal network component 118 is a security services module 114 . Security services module 114 is communicatively coupled to gateway 112 , and performs security functions such as encryption, decryption, key management, and/or any other functions suitable for ensuring the security, confidentiality, and/or integrity of data communicated throughout system 100 .
Another internal network component 118 is home value module 106 , which includes a memory or other electronic storage device (not shown) that electronically stores information related to electronic assets owned by the issuer. For example, home value 106 can store data entries representing credit, deposits, loyalty points, reward points, media, and the like. Each data entry of home value 106 has a value-base and an associated quantitative and/or qualitative value that also are stored in the memory (not shown) and are used by trust mediator 116 in order to assess security risks associated with that particular data entry.
Internal network components 118 also include a value mediator 104 , which valuates electronic assets owned by an entity other than the issuer. These assets have a value-base other than the value-bases stored in home value 106 . Value mediator 104 thus enables quantification and exchange of value across different value-bases. In addition, by valuating these assets, value mediator 104 enables risk magnitude quantification associated with these assets to be computed by trust mediator 116 . For example, if the value of the transaction or commerce was an asset calculated by value mediator 104 , then this computed value is input to trust mediator 116 to react by changing one or more protections, countermeasures, or policies related to the asset.
Trust mediator (TM) agents 108 a - 108 f (collectively 108 ) are deployed on external terminal 102 , visiting network 110 , gateway 112 , security services module 114 , value mediator 104 , and home value module 106 , respectively. TM agents 108 detect and assess security-related information collected from one or more sensors corresponding to each respective network component and communicate this information to trust mediator 116 . The sensors measure a physical quantity, such as an electronic signal or other data, and convert it into a signal which can be read by an observer and/or by an instrument, such as the TM agents 108 or trust mediator 116 . Trust mediator 116 , in turn, communicates instructions to TM agents 108 to modify implementation of security safeguards. Trust mediator 116 also assesses information received from the TM agents 108 and determines whether and/or how to modify security safeguards according to security and/or trust mediation algorithms that can be singular or a summation of plural safeguards and countermeasures interchangeable based on security goals.
FIG. 2 is a flowchart illustrating an exemplary process 200 for adapting security measures of a communication network based on dynamic feedback in accordance with an embodiment of the present invention. In this example embodiment, external terminal 102 is a mobile telephone. It should be understood, however, that the external terminal 102 is not limited to a mobile telephone. For example, a personal computer, a POS device, a personal digital assistant (PDA), a portable computing device, or the like, can be used instead and still be within the scope of the invention.
Referring to both FIGS. 1 and 2 , variables used throughout process 200 are initialized with seed values. These variables are stored in a memory or other electronic storage device (not shown) located in one or more of internal network components 118 . Example variables include values, attributes, and weighting factors for electronic assets, a user expectation of trust, a user expectation of convenience, an attack time, a safeguard time, a transaction location profile for user 122 , a transaction time profile for user 122 , etc. As process 200 progresses, the initial values of the variables are updated based on feedback processes and probes which are described in further detail below.
At block 206 , one or more of TM agents 108 a - 108 f detects an event. For example, TM agent 108 a or 108 b detects the connecting of external terminal 102 to visiting network 110 , a request by external terminal 102 connected to visiting network 110 to complete a financial transaction, a request to associate a new external terminal 102 with a financial account of user 122 , a change in a condition such as the time or location of external terminal 102 , etc.
The other TM agents 108 , either in parallel or in response to a detection made by TM agents 108 a and 108 b , can detect events such as the presence of a security threat associated with any of the internal and external network components 118 and 120 , the safeguards currently in place for internal and external network components 118 and 120 , information input by user 122 via external terminal 102 regarding expectation of safeguards, etc.
In response to any of TM agents 108 a - 108 f detecting an event, the corresponding TM agent 108 a - 108 f communicates updated information related to the event to trust mediator 116 . Alternatively, or additionally, trust mediator 116 periodically polls one or more of TM agents 108 a - 108 f for updated information at a rate determined by trust mediator 116 to be appropriate. For example, trust mediator 116 may poll TM agent 108 a for data as to the location of external terminal 102 requesting multiple transactions. If data from TM agent 108 a indicates a random shopping pattern because external terminal 102 is moving rapidly across different external network components 120 (e.g., because user 122 is on a train), trust mediator 116 can signal the other TM agents 108 b - 108 f about this activity and poll more frequently.
A broad spectrum of risks are managed by dynamically measuring various risk factors using TM agents 108 a - 108 f that are fed data from sensors. Each sensor measures a physical quantity and converts it into a signal that is stored as a risk variable by the TM agents 108 a - 108 f , respectively, and is forwarded to the trust mediator 116 , as necessary. For example, one type of sensor is a tactile sensor that converts vibrations into a signal that is stored in a corresponding risk variable, which in turn can be read by the TM agents 108 a - 108 f and communicated to the trust mediator 116 . Another example is a speed sensor that converts speed to a value that is stored in another risk variable. Another example is an accelerometer that senses and converts orientation, vibration, and/or shock into a value that is stored in another risk variable. Yet another example is a biometric sensor that senses and converts a physical characteristic of a human into a value that is stored in another risk variable. Still another example is a software sensor that senses changes in usage based on, e.g., input, output, location, etc., and stores the result in another risk variable.
Each external and internal network component 120 and 118 has one or more associated sensors feeding data to the respective TM agent 108 a - 108 f , and the data is stored in a corresponding risk variable. The one or more risk variables associated with a particular network component can be grouped into clusters to derive one or more risk spaces for the network component. Different clusters and/or risk spaces can be derived by using different risk variables and/or different data collection techniques based on various data collection factors. For example, the cluster of risk variables for a particular network component can be dynamically changed by one or more of TM agents 108 a - 108 f or trust mediator 116 based on the instant condition (e.g., environment, location, speed, etc.).
In one aspect, data for each risk space can be collected at a predetermined sampling rate from the sensors in the cluster by the respective TM agent 108 a - 108 f . Sampling rates can be modified based on the instant condition, and/or based on security goals (e.g., goals regarding protection time, detection time, and reaction time, which are further described below).
In another aspect, TM agents 108 can communicate the data for each risk space to trust mediator 116 at a rate corresponding to the sampling rate.
In another aspect, data for each risk space can be communicated by one or more of TM agents 108 a - 108 f to trust mediator 116 as a running summation of measurements collected over a predetermined integration time period. The integration time period can also be modified based on various data collection factors. For example, if the sample rate is set to 2 sample per second, and trust mediator 116 sets a 10 second integration period for a particular TM agent 108 a - 108 f , then trust mediator 116 will receive summations of every consecutive 20 samples from the corresponding TM agent 108 a - 108 f.
In yet another aspect, data for each risk space can be periodically communicated to trust mediator 116 in bursts of data (also referred to as block measurement). The intervals between the block measurements can also be modified based on data collection factors. In another aspect, TM agents 108 and/or trust mediator 116 can normalize the data that produces each risk space by computing a weighted and/or a non-weighted sum of the data from the sensors in the cluster.
The collection and/or use of the various risk variable data points is determined dynamically by trust mediator 116 . For example, trust mediator 116 can change the clusters for each network component, and/or change the above-mentioned data collection rates and techniques, based on detected risks, goals (e.g., protection time, detection time, and reaction time), and/or other dynamic factors (e.g., data communicated to trust mediator 116 from one or more of TM agents 108 a - 108 f ). This provides system 100 with a greater adaptability and versatility when compared to typical security systems.
Typical network agents deny or grant access to network resources based on the current protection mechanisms. TM agents 108 a - 108 f , however, use the sensors to detect any risk factors that impact a risk profile for each network component, and in response to the sensing, can not only deny or grant access based on the current protection mechanisms, but can also assist in changing the protection mechanisms so that access and commerce can continue. In this way, process 200 is dynamic in nature, as opposed to typical network security processes, which are static in nature.
Other information communicated by TM agents 108 a - 108 f to trust mediator 116 includes information relating to safeguards currently deployed throughout system 100 . Trust mediator 116 uses this information to compute safeguard time (which may also be referred to as protection time). In particular, trust mediator 116 computes safeguard time as the total amount of secure time provided by all the security safeguards that are currently in place in system 100 from end to end. Once trust mediator 116 computes safeguard time, the computed value of safeguard time replaces the initialized value of safeguard time discussed above.
TM agents 108 a - 108 f communicate information to trust mediator 116 relating to current security threats present throughout system 100 . Trust mediator 116 uses this information to compute attack time for the current threats. Attack time is an amount of time it would take for a detected threat to circumvent the currently running safeguards. For example, if a particular encryption algorithm is used as the current safeguard, then the attack time is the risk factor in time predicted for a computer with the average computing power to crack the protection mechanisms, which can include the encryption algorithm, pairing, and/or authentication, using brute force or cryptanalysis methods. Once trust mediator 116 computes the attack time, the computed value of attack time replaces the initialized value of attack time discussed above.
TM agent 108 a receives user input from external terminal 102 relating to user expectation of trust and communicates this information to trust mediator 116 . Trust mediator 116 uses this information to compute a user expectation of trust for user 122 . User expectation of trust represents the level of protection required by user 122 in connection with particular transactions, and can be based on the type of transaction requested by user 122 via external terminal 102 . For example, user 122 may require a higher level of security (and hence a higher safeguard time) for transactions over a certain amount of money. Once trust mediator 116 computes user expectation of trust, the computed value of user expectation of trust replaces the initialized value of user expectation of trust discussed above.
TM agent 108 a also receives user input from external terminal 102 relating to user expectation of convenience and communicates this information to trust mediator 116 . Trust mediator 116 uses this information to compute a user expectation of convenience for user 122 . User expectation of convenience represents the maximum inconvenience that user 122 will accept in association with safeguards. User expectation of convenience also is based on the type of transaction requested by user 122 via external terminal 102 . For example, user 122 may be unwilling to accept the inconvenience associated with requiring user 122 to submit to a biometric identification process, such as an iris scan, for a transaction of $5. Once trust mediator 116 computes user expectation of convenience, the computed value of user expectation of convenience replaces the initialized value of user expectation of convenience discussed above.
TM agents 108 a - 108 f communicate information to trust mediator 116 relating to security threats of internal network components 118 and external network components 120 . Trust mediator 116 stores this information in a memory (not shown) for use in quantifying security risk and determining the appropriate safeguards to counter the risk.
At block 204 , trust mediator 116 compares the computed value of safeguard time to the computed value of attack time to determine whether the safeguard time provided by the currently running safeguards is less than the attack time. If trust mediator 116 determines that the safeguard time is greater than or equal to the attack time, then system 100 is considered secure, in other words, there is no time period during which the system 100 is exposed to threats. In this case, the procedure continuously repeats block 204 using updated information, if any, communicated at block 206 from TM agents 108 to trust mediator 116 . In this way, the procedure is recursive and is able to continuously and dynamically adapt to changes in security characteristics.
If trust mediator 116 determines, however, that safeguard time is less than attack time, then the procedure continues to block 208 . At block 208 , trust mediator 116 determines whether the current safeguard time satisfies the computed user expectation of trust and the computed user expectation of convenience. This determination includes comparing the computed safeguard time against both the computed user expectation of trust and the computed user expectation of convenience. Safeguard time fails to satisfy the user expectation trust if the safeguard time provided by the currently running safeguards is less than the minimum security level user 122 will accept for the transaction (e.g., only requiring a mother's maiden name for a $10,000 transaction). Safeguard time also fails to satisfy the user expectation of convenience if the inconvenience associated with the currently deployed safeguards exceeds the maximum inconvenience user 122 will accept for the transaction (e.g., requiring an iris scan for a $5 transaction). If the trust mediator 116 determines that the safeguard satisfies both user expectation of trust and user expectation of convenience then the procedure progresses to block 210 .
At block 210 , user 122 uses external terminal 102 to input information relating to user expectation of trust, user expectation of convenience, and/or safeguards, as desired. Trust mediator 116 stores and uses this information to compute an equilibrium point that optimally balances user expectation of trust and user expectation of convenience for user 122 based on transaction characteristics. For example, if the stored user expectation data indicates that user 122 typically requires more rigorous safeguards (higher safeguard time) for transactions involving amounts above $1,000 than for those below $1,000, trust mediator 116 uses more rigorous safeguards for transactions above $1,000 and less rigorous safeguards for transactions below $1,000. This increases user's 122 satisfaction with system 100 because both trust and convenience are optimized and personalized for individual users 122 .
After block 208 or block 210 , as the case may be, the procedure progresses to block 212 . If trust mediator 116 determines at block 208 that safeguard time satisfies user expectation of trust and user expectation of convenience, then at block 212 trust mediator 116 enables, disables, and/or modifies one or more safeguards according to the information input by user 122 at block 210 , if any.
Alternatively, if trust mediator 116 determines at block 208 that safeguard time fails to satisfy user expectation of trust and/or user expectation of convenience, then at block 212 trust mediator 116 enables, disables, and/or modifies safeguards according to one or more trust mediation algorithm(s).
Example safeguard modifications include increasing a key length, changing an encryption algorithm, changing an authentication method, etc. Safeguard modifications help thwart attackers' attempts to circumvent safeguards. For example, changing an encryption key and/or an encryption algorithm during run-time increases the difficulty of an attacker successfully circumventing the encryption.
One variable that is used by trust mediator 116 in determining whether and/or how to modify safeguards for a transaction is the risk associated with transaction data (electronic assets) stored in and/or communicated throughout system 100 . Trust mediator 116 computes risk as the product of a value (magnitude) of specific transaction data and the probability that the specific transaction data will be compromised.
The value of the specific transaction data is determined in one of two ways depending on the value-base of the specific transaction data. If the transaction data is based on a value-base stored in home value 106 (e.g., U.S. dollars, euros, etc.), then home value 106 computes the value of the specific transaction data based on that value-base. Home value 106 computes the value of the specific transaction data and communicates the value to trust mediator 116 for computing the risk associated with the specific transaction data.
If the specific transaction data is based on a value-base that is not stored in home value 106 (e.g., an unknown currency), then value mediator 104 computes the value of the specific transaction data using a valuation formula, which could be supported by one or multiple value transitions to reach like terms and comparable mediation weights. Value mediator 104 enables trust mediator 116 to assess risk for values not based on value-bases stored in home value 106 , and enables transfer of value across value-bases. Inputs to the valuation formula include attributes of the specific transaction data as well as weighting factors corresponding to each of the attributes. Examples of the attributes of specific transaction data include: an owner of the specific transaction data, a time or location of the associated transaction, a currency of the specific transaction data, etc.
As mentioned above, if user 122 has not yet used system 100 to complete any transactions, then initialized values of the attributes and the weighting factors are used in the valuation formula. Over time, as user 122 completes transactions using system 100 , the values of the attributes and the weighing factors are updated in the memory (not shown) and are used in the valuation and risk formula.
If the values of the attributes and weighing values converge over time, then trust mediator 116 uses the converged values of the attributes of a user's 122 transactions to assess risk of future transactions. These converged values are used by trust mediator 116 in computing the probability that specific transaction data will be compromised. For example, if the converged values for user 122 indicate that user 122 typically enters transactions during a particular time and/or at a particular geographical location, then trust mediator 116 increases the probability that specific transaction data will be compromised for any transaction from user 122 that originates at a different time and/or location than those indicated by the converged data. Conversely, trust mediator 116 decreases the probability that specific transaction data will be compromised for any transaction from user 122 that originates at approximately the time and/or location indicated by the converged data. Thus, exposure to risk is minimized through continuous dynamic improvement and convenience equilibrium for user 122 is maximized. Value mediator 104 transmits the computed value of the specific transaction data to trust mediator 116 for computing the risk associated with the specific transaction data.
As mentioned above, trust mediator 116 collects data from TM agents 108 a - 108 f using various data collection techniques (e.g., cluster-based collection, event-based collection, and/or sampling rate-based collection, etc.). Trust mediator 116 can also periodically poll TM agents 108 a - 108 f for information as to the time required for TM agents 108 a - 108 f to detect threats (detection time). Trust mediator 116 also keeps track of the time taken for system 100 to react to previously detected threats by implementing adjusted safeguards (reaction time). If trust mediator 116 determines that safeguard time is less than the product of the detection time and the reaction time, then trust mediator 116 increases the rate at which it polls TM agents 108 a - 108 f to decrease the detection time.
From block 212 , the procedure progresses to block 214 . At block 214 , trust mediator 116 determines whether modifications to the safeguards determined at block 212 satisfy the attack time, the user expectation of trust, and the user expectation of convenience. If the trust mediator 116 determines that the safeguards fail to satisfy the attack time, the user expectation of trust, and/or the user expectation of convenience, then the procedure repeats block 212 to further modify the safeguards as needed. If trust mediator 116 determines that the safeguards satisfy the attack time, the user expectation of trust, and the user expectation of convenience, then the procedure progresses to block 216 .
At block 216 , the trust mediator 116 communicates the safeguard modifications to one or more of the TM agents 108 a - 108 f . For instance, the trust mediator 116 communicates changes in safeguards relating to security services to security services module 114 to implement the new security services and safeguards (e.g., a different encryption/decryption algorithm). In this case, the safeguard modification is sent to at least two network components, namely, the component that performs the encrypting of data and the component that performs the decrypting of data. In one embodiment security services module 114 implements security applications based on the Diameter protocol and/or other authentication, authorization and accounting (AAA) protocols.
From block 216 , the procedure repeats block 204 with new information communicated from TM agents 108 at block 206 , if any exists. In this way, the procedure is recursive and thus is able to continuously and dynamically adapt to changes in the security situation as they arise over time and/or the particular location of external terminal 102 . Users 122 can thus use their external terminals 102 to complete financial transactions using system 100 while experiencing an adaptive level of security that is both effective and convenient for user 122 . Moreover, issuers can enable consumers to use their financial transaction accounts over their mobile telephones to complete transactions in various geographical locations, while maintaining an adaptive level of security that is effective and not over burdensome for user 122 .
The present invention (e.g., system 100 , process 200 , or any part(s) or function(s) thereof) can be implemented using hardware, software or a combination thereof and can be implemented in one or more computer systems or other processing systems. However, the manipulations performed by the present invention were often referred to in terms, such as adding or comparing, which are commonly associated with mental operations performed by a human operator. No such capability of a human operator is necessary, or desirable in most cases, in any of the operations described herein which form part of the present invention. Rather, the operations are machine operations. Useful machines for performing the operation of the present invention include general purpose digital computers or similar devices.
In fact, in one embodiment, the invention is directed toward one or more computer systems capable of carrying out the functionality described herein. An example of a computer system 300 is shown in FIG. 3 .
Computer system 300 includes one or more processors, such as processor 304 . The processor 304 is connected to a communication infrastructure 306 (e.g., a communications bus, cross-over bar, or network). Various software embodiments are described in terms of this exemplary computer system. After reading this description, it will become apparent to a person skilled in the relevant art(s) how to implement the invention using other computer systems and/or architectures.
Computer system 300 can include a display interface 302 that forwards graphics, text, and other data from the communication infrastructure 306 (or from a frame buffer not shown) for display on the display unit 330 .
Computer system 300 also includes a main memory 308 , preferably random access memory (RAM), and can also include a secondary memory 310 . The secondary memory 310 can include, for example, a hard disk drive 312 and/or a removable storage drive 314 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive 314 reads from and/or writes to a removable storage unit 318 in a well known manner. Removable storage unit 318 represents a floppy disk, magnetic tape, optical disk, etc. which is read by and written to by removable storage drive 314 . As will be appreciated, the removable storage unit 318 includes a computer usable storage medium having stored therein computer software and/or data.
In alternative embodiments, secondary memory 310 can include other similar devices for allowing computer programs or other instructions to be loaded into computer system 300 . Such devices can include, for example, a removable storage unit 322 and an interface 320 . Examples of such can include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an erasable programmable read only memory (EPROM), or programmable read only memory (PROM)) and associated socket, and other removable storage units 322 and interfaces 320 , which allow software and data to be transferred from the removable storage unit 322 to computer system 300 .
Computer system 300 can also include a communications interface 324 . Communications interface 324 allows software and data to be transferred between computer system 300 and external devices. Examples of communications interface 324 can include a modem, a network interface (such as an Ethernet card), a communications port, a Personal Computer Memory Card International Association (PCMCIA) slot and card, etc. Software and data transferred via communications interface 324 are in the form of signals 328 which can be electronic, electromagnetic, optical or other signals capable of being received by communications interface 324 . These signals 328 are provided to communications interface 324 via a communications path (e.g., channel) 326 . This channel 326 carries signals 328 and can be implemented using wire or cable, fiber optics, a telephone line, a cellular link, a radio frequency (RF) link and other communications channels.
In this document, the terms “computer program medium,” “computer-readable medium,” and “computer-usable medium” are used to generally refer to media such as removable storage drive 314 , a hard disk installed in hard disk drive 312 , and/or signals 328 . These computer program products provide software to computer system 300 . The invention is directed to such computer program products.
Computer programs (also referred to as computer control logic) are stored in main memory 308 and/or secondary memory 310 . Computer programs can also be received via communications interface 324 . Such computer programs, when executed, enable the computer system 300 to perform the features of the present invention, as discussed herein. In particular, the computer programs, when executed, enable the processor 304 to perform the features of the present invention. Accordingly, such computer programs represent controllers of the computer system 300 .
In an embodiment where the invention is implemented using software, the software can be stored in a computer program product and loaded into computer system 300 using removable storage drive 314 , hard drive 312 or communications interface 324 . The control logic (software), when executed by the processor 304 , causes the processor 304 to perform the functions of the invention as described herein.
In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s).
In yet another embodiment, the invention is implemented using a combination of both hardware and software.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the present invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
In addition, it should be understood that the figures illustrated in the attachments, which highlight the functionality and advantages of the present invention, are presented for example purposes only. The architecture of the present invention is sufficiently flexible and configurable, such that it can be utilized (and navigated) in ways other than that shown in the accompanying figures.
Further, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is not intended to be limiting as to the scope of the present invention in any way. It is also to be understood that the steps and processes recited in the claims need not be performed in the order presented.
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An adaptable network security system includes trust mediator agents that are coupled to each network component. Trust mediator agents continuously detect changes in the security characteristics of the network and communicate the detected security characteristics to a trust mediator. Based on the security characteristics received from the trust mediator agents, the trust mediator adjusts security safeguards to maintain an acceptable level of security. Trust mediator also uses predetermined rules in determining whether to adjust security safeguards. Despite inevitable changes in security characteristics, an acceptable level of security and efficient network operation are achieved without subjecting users of the network to over burdensome security safeguards.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/134,243, filed Mar. 17, 2015, titled “Sub-Nanosecond Time of Flight on Commercial Wi-Fi Cards,” which is incorporated herein by reference.
FEDERAL SPONSORSHIP
[0002] This invention was made with government support under contract FA8721-05-C-0002 awarded by the U.S. Air Force and under grant CNS1117194 awarded by the National Science Foundation. The government has certain rights in the invention.
BACKGROUND
[0003] This application relates to estimation of radio frequency propagation time (“time of flight”) between radio transceivers, and more particularly relates to sub-decimeter range estimation between two wireless local area network (“WiFi”) transceivers.
[0004] Radio frequency transmissions propagate at approximately 3×10 8 meters per second. Therefore, in order to use a propagation time to estimate a propagation distance to an accuracy of 0.1 meters (a decimeter), the time must be known to an accuracy of greater than 0.3 nanoseconds. That is, sub-nanosecond accuracy is necessary for such an approach to distance estimation.
[0005] Prior approaches have been presented to resolve time of flight to approximately 10 nanoseconds using the clocks of WiFi cards or other related methods. However, the accuracy of such approaches is insufficient for decimeter range accuracy.
[0006] One use of propagation time or distance estimation is localization. Others have attempted to use WiFi transceivers for sub-meter accuracy of localization. However, such prior approaches have not directly measured propagation time or distance between transceivers. For example, multiple reference transceivers are needed to infer a location of a target transceiver using differences in propagation time between different reference transceivers and a transceiver at an unknown location, rather than absolute propagation times, may be used to infer a location of a target transceiver. For example, such differences in propagation time may be used to determine direction of arrival, which in turn is used to determine the target location by triangulation.
[0007] State-of-the-art systems may achieve an accuracy of tens of centimeters, even using commodity WiFi chipsets. Such systems generally target enterprise networks, where multiple WiFi access points can combine their information and cooperate together to locate a target device. However, the vast majority of homes and small businesses today have a single WiFi access point and therefore such multiple-access-point approaches are not applicable.
[0008] There exist non-WiFi systems that can accurately measure the absolute time of flight, and hence localize using a single receiver. Such systems generally use specialized ultra wideband radios that span multiple giga-Hertz. Because time resolution is inversely related to the radio bandwidth, such devices can measure time of flight at sub-nanosecond accuracy, and hence localize an object to within tens of centimeters. In contrast, directly measuring time with a 20 or 40 mega-Hertz bandwidth equivalent to a WiFi radio transmission would result in errors of 7 to 15 meters using such techniques.
[0009] Prior work has failed to recognize and/or provide effective solutions to overcome effects that make it difficult to make accurate over-the-air propagation time estimates between two WiFi transceivers. These effects include:
Limited transmission bandwidth Carrier frequency offset between transceivers Unknown packet detection delay at receivers Sampling frequency offset between transceivers Multiple propagation paths between transceivers
[0015] There is a need to improve available technology for distance estimation, and in particular to overcome one or more of these effects to achieve improved time and/or distance accuracy.
SUMMARY
[0016] In one aspect, in general, embodiments presented herein improve on the technology of time-of-fight estimation by addressing one or more of the effects of carrier frequency offset (CFO) between transceivers, unknown packet detection delay at a receiver, sampling frequency offset (SFO) between transceivers, and multipath propagation between transceivers. At least some embodiments make use of two characteristics of communication packets that are transmitted between a pair of transceivers:
1. Communication packets that encode information on multiple sub-carriers over a relatively narrow bandwidth, for example, using orthogonal frequency division multiplexing (OFDM) encoding; and 2. Communication packets that are transmitted at widely separated carrier frequencies, for example, on multiple communication channels and/or on different communication bands, with the separation of the carrier frequencies being substantially greater than the bandwidth of any individual packet.
[0019] In another aspect, in general, multiple packets transmitted on different frequency bands are used to essentially emulate a wireband transmission. The measurements are “stitched” together to determine the propagation time. One or more embodiments overcome the following challenges to such stitching together of the transmissions:
1. Resolving Phase Offsets: To emulate a wideband radio, the system combines channel state information (CSI) captured by multiple packets, transmitted in different WiFi frequency bands, at different points in time. However, the very act of hopping between WiFi frequency bands introduces a random initial phase offset as the hardware resets to each new frequency (i.e., PLL locking). The system recovers time of flight to perform positioning despite these random phase offsets; 2. Eliminating Packet Detection Delay: Measurement of time of flight of a packet generally includes the delay in detecting its presence. Different packets however experience different random detection delays. To make matters worse, this packet detection delay is typically orders-of-magnitude greater than time of flight. For indoor WiFi environments, time of flight is just a few nanoseconds, while packet detection delay spans hundreds of nanoseconds. The system teases apart the time of flight from this detection delay; and 3. Combating Multipath: In indoor environments, signals do not experience a single time of flight, but a time-of-flight spread. This is because RF signals in indoor environments bounce off walls and furniture, and reach the receiver along multiple paths. As a result, the receiver obtains several copies of the signal, each having experienced a different time of flight. To perform accurate localization, the system disentangles the time of flight of the direct path from all the remaining paths.
[0023] In one aspect, in general, a method for determining a separation of two radio nodes includes receiving a first plurality of radio frequency transmissions from a second radio node to a first radio node. Each transmission includes a signal transmitted from the second radio node at a second location to the first radio node at a first location. The first location of the first radio and the second location are separated by a range. Each transmission has a transmission frequency different than the transmission frequencies of the other transmissions of the plurality of transmissions. A constraint on the range is determined from each of the transmissions, and each constraint is consistent with a plurality of possible ranges. The plurality of possible ranges of the constraint is dependent on the transmission frequency of the transmission. The constraints determined from each of the transmissions are then combined to determine an estimate of the range.
[0024] Aspects can include combinations of one or more of the following features.
[0025] Determining the constraint from a transmission comprises determining a phase difference at the transmission frequency between the signal transmitted at the second radio node and the signal received at the first radio node. The constraint on the range is the determined to be such that the range is substantially equal to a fraction of a wavelength plus a set of integer multiples of said wavelength, where the wavelength corresponds to the transmission frequency and the fraction corresponds to the determined phase difference.
[0026] The constraint on the range requires that a propagation time, τ, corresponding to said range be equal to −(∠h 1 )/(2πf i ) modulo 1/f i for all the transmission frequencies f i of the transmissions and the corresponding determined phase differences ∠h i .
[0027] Combining the constraints comprises determining a constraint on the range relative to a least common multiple of the wavelengths of the transmission frequencies.
[0028] Each signal of at least some of the plurality of transmissions includes a plurality of components at a set of distinct non-zero frequency offsets from the transmission frequency.
[0029] The phase difference at the transmission frequency is determined by determining a phase difference at each of the frequency offsets and then extrapolating the phases differences at said frequency offsets to determine the phase difference at the transmission frequency.
[0030] The signal comprises an Orthogonal Frequency Division Multiplexed (OFDM) modulation of data, and each component of the signal corresponds to a different component of the OFDM modulation.
[0031] The plurality of radio frequency transmissions comprise wireless local area network transmissions.
[0032] For each transmission from the second radio node to the first radio node, a transceiver frequency reference at the second radio node has a phase offset relative to a transceiver frequency reference at the first radio node.
[0033] Determining the phase difference comprises mitigate an effect of the phase offset of the transceiver frequency references at the first and first radio nodes.
[0034] Mitigating the effect of the phase offset in determining the phase difference at the transmission frequency of a first transmission of the plurality of transmissions includes: (a) recording a first measurement at the first radio node characterizing a first phase difference of the signal of the first transmission; (b) making a second transmission at the transmission frequency of the first transmission from the first radio node to the second radio node; (c) recording a second measurement characterizing a second phase difference of the signal of the second transmission at the second radio node; and (d) combining the first measurement and the second measurement to determine the phase difference between the second radio node and the first radio node at the transmission frequency.
[0035] The first phase difference includes an additive factor corresponding to the phase offset, and the second phase difference includes an additive factor that is substantially the negative of the additive factor of the first phase difference, and where combining the first measurement and the second measurement includes adding the first phase difference and the second phase difference.
[0036] Combining the first measurement and the second measurement further includes mitigating an effect of delay (e.g., a fixed hardware-related delay) between the first transmission and the second transmission.
[0037] Combining the first measurement and the second measurement include adding a factor corresponding to the delay between the first transmission and the second transmission.
[0038] Each transmission of at least some of the first plurality of transmissions has multiple paths between the second radio node and the first radio node including a direct path having direct propagation time corresponding to the range between the second radio node and the first radio node, and one or more indirect paths (e.g., reflecting off walls or other fixed structures in the environment) having indirect propagation times greater than said direct propagation time.
[0039] Each constrain corresponds to a value in a frequency domain representation of the propagation times as a function of transmission frequency.
[0040] Combining the constraints comprises performing a transform computation using the values in the frequency domain representation of the propagation times.
[0041] The transmission frequencies are non-uniformly spaced.
[0042] Performing the inverse transform computation comprises performing a Non-uniform Discrete Fourier Transform (NDFT) computation.
[0043] Combining the constraints to determine the estimate of the range comprises determining a peak in a time-domain representation resulting from the transform computation with a smallest time.
[0044] The plurality of radio frequency transmissions comprise wireless local area network transmissions.
[0045] The plurality of radio frequency transmissions comprise multiple channel frequencies in multiple frequency bands of a wireless communication system.
[0046] The plurality of radio frequency transmissions have transmission frequencies that span a range of at least a multiple of two between a lowest and a highest transmission frequency.
[0047] The plurality of radio frequency transmissions have transmission frequencies that are not multiples of a common transmission frequency.
[0048] The transmission frequencies are not all regularly spaced.
[0049] In another aspect, in general, software stored on a non-transitory machine-readable media comprising instructions for causing one or more processors to: (a) process a plurality of radio frequency transmissions from a second radio node, each transmission having a transmission frequency of the plurality of frequencies different than the transmission frequencies of the other transmissions of the plurality of transmissions; (b) determine a constraint on a range from the second radio node from each of the transmissions, each constraint being consistent with a plurality of possible ranges, the plurality of possible ranges of the constraint being dependent on the transmission frequency of the transmission; and (c) combine the constraints determined from each of the transmissions to determine an estimate of the range.
[0050] In another aspect, in general, software stored on a non-transitory machine-readable media comprising instructions for causing one or more processors to perform all the step of any one of the methods presented above.
[0051] In another aspect, in general, a radio node is configured to determining a separation from a second radio node. The node comprises a radio receiver configured to receive transmissions at a first plurality of frequencies and a processor. The processor is configured to: (a) process a first plurality of radio frequency transmissions from a second radio node, each transmission having a transmission frequency of the first plurality of frequencies different than the transmission frequencies of the other transmissions of the plurality of transmissions; (b) determine a constraint on a range from the second radio node from each of the transmissions, each constraint being consistent with a plurality of possible ranges, the plurality of possible ranges of the constraint being dependent on the transmission frequency of the transmission; and (c) combine the constraints determined from each of the transmissions to determine an estimate of the range.
[0052] In another aspect, in general, a radio node is configured to determining a separation from a second radio node. The node comprises (a) a radio receiver configured to receive transmissions at a first plurality of frequencies; and (b) a processor configured to perform all the step of any one of the methods presented above.
[0053] In another aspect, in general, a system includes a plurality of nodes, including a first node and a second node, configured to determine a range between said nodes according to any one of the methods presented above. In some examples, the first node is a WiFi access point and the second node is a mobile WiFi device.
[0054] In another aspect, in general, a system includes a plurality of nodes. The nodes are configured to determined ranges between pairs of nodes according to any one of the methods presented above. Locations of the nodes (e.g., relative to one another) are then determined from the determined ranges.
[0055] An advantage of one or more embodiments is that a single WiFi node (e.g., an access point) can determine a position relative to (i.e., localize) and/or determine a range to another node without support from additional infrastructure. Further, the approach can be deployed on commodity WiFi Network Interface Controllers (NICs) and does not require additional sensors (cameras, accelerometers, etc.).
DESCRIPTION OF DRAWINGS
[0056] FIG. 1 is an illustration of an indoor environment in which a distance between two wireless nodes is estimated using transmissions between the nodes.
[0057] FIG. 2 is a block diagram of components of the wireless nodes shown in FIG. 1 .
[0058] FIG. 3 is a block diagram of an input physical layer (“PHY”) shown in FIG. 2 .
[0059] FIG. 4 is an illustration of an approach to combining modular time estimates at different frequencies.
[0060] FIG. 5 is an illustration of multiple transmission paths with attenuation.
[0061] FIG. 6 is a testbed with candidate locations for the nodes marked with dots.
[0062] FIG. 7 is a cumulative distribution function (CDF) of error in time-of-flight between two devices in Line-of-Sight (LOS) and Non-Line-Of-Sight (NLOS) conditions.
[0063] FIG. 8 is an example of a time profile in a LOS and a NLOS condition.
[0064] FIG. 9 is histogram of time-of-flight and packet detection delay.
[0065] FIG. 10 is is a plot of error in distance across the true distance separating the transmitter from the receiver.
[0066] FIG. 11 is is a plot of CDF of localization error in Line-of-Sight (LOS) and Non-Line-of-Sight (NLOS).
DETAILED DESCRIPTION
Notation
[0067] The following notation is generally used in the description below. In the case of inconsistency between this list and the text of the description, text should be followed.
τ is the true propagation time (time of flight) between two nodes. In the case of multiple paths, τ 0 denotes the time on a direct path, and τ p denotes the delay on the p th indirect path. d is the true range between the nodes, d=c/τ where c is the propagation speed. f 0 is the frequency of local oscillator, which determines the carrier frequency of a transmission (in Hertz). tx rx In general, superscript tx denotes a quantity at the node initiating a range measurement (i.e., the transmitter of an initial packet) and superscript rx denotes the quantity at the node to which the range is being determined. In general, an optional initial subscript i denotes a quantity for an i th measurement (1≦i≦N). For example, f i,0 rx denotes the local oscillator frequency at a receiver on the i th measurement (e.g., at the i th frequency band). φ 0 is the phase of the corresponding oscillator (in degrees). f k is the frequency of the k th subcarrier (1≦k≦K) of a transmission (i.e., the first subcarrier is spaced f i −f 0 from the carrier of the transmission). When presented with two indices as f i,k , the first index i denotes the channel of the transmission and the second index, k, denotes the subcarrier. h k is the true over-the-air propagation channel of the k th subcarrier. The phase of the channel is denoted ∠h k (in Radians). In the case of a pure delay and no indirect paths, then ∠h 0 =−2πf 0 τ mod 2π. When presented with two indices as h i,k , the first index i denotes the channel of the transmission and the second index, k, denotes the subcarrier. δ is the packet detection time delay. {tilde over (h)} k is a channel estimate for the k th subcarrier including the effect of the packet detection delay. In the case of a pure delay and no indirect paths, then ∠{tilde over (h)} 0 =−2πf 0 (τ+δ) mod 2π.
1 System Overview
[0077] FIGS. 1-3 illustrate general characteristics of a system 100 for determining the separation of WiFi nodes 102 , 104 . Referring to FIG. 1 , in this example, the nodes 102 , 104 comprise an access point 102 and a handheld device (e.g., smartphone) 104 . The system makes use of communication packets transmitted between the nodes the over the over-the-air path 110 between the nodes. The direct over-the-air path 110 is shown as a solid line, and a number of indirect paths 112 A-B, which are longer than the direct path 110 , reflecting off objects in the environment, are shown as dashed lines. As discussed further below, the system 100 makes use of computation components (e.g., computers, embedded processors or controllers, using software stored on media, etc.) hosted at one or both of the nodes 102 , 104 , and optionally further uses computation resources not illustrated in FIG. 1 (e.g., at a computation server linked to the access point 102 ). Very generally, the system makes use of propagation times τ on the direct path 110 , along with the known signal propation speed (c), to determine the range of node 104 from node 102 .
[0078] Referring to FIG. 2 , each of the nodes 102 , 104 includes a number of packet processing components, including a controller 230 . The controllers 230 at the nodes cooperate to determine the range estimate. Each node includes a local oscillator 212 , which is responsive to a channel setting command to provide a reference (e.g., local oscillator) signal at a frequency f 0 to a demodulator 214 for inbound transmissions and a modulator 224 for outbound transmissions, both coupled to an antenna 210 . The output of the demodulator 214 comprises a baseband signal that is provided to the input phy layer 216 , which in turn provides data packets to input packet processor 216 . On the output path, an output packet processor 226 provides data packets to the output phy layer 226 , which in turn passes a baseband signal via the modulator 224 to the antenna 210 .
[0079] In a number of embodiments described below, the transmissions between nodes make use of multiple sub-carriers. In particular, a number of embodiments make use of orthogonal frequency division multiplexing (OFDM) in which each transmission packet includes a sequence of symbols, and each symbol is encoded as a sum of modulated subcarriers at orthogonal frequencies. Each transmission packet also includes a preamble, which is used for detection of the packet at the receiver, and as described below, may be used for compensating for differences in local oscillator frequency between the transmitter and receiver. Referring to FIG. 3 the input phy layer 216 includes a sampler and analog-to-digital converter (ADC), which provides a sequence of complex values (i.e., the two quadrature components of the demodulated baseband signal). This sequence is provided to a packet detector 342 . In some implementations, the packet detector makes use of a repeating pattern in the preamble to detect the start of a data packet. Note that the detection is not in general precise, and the time of detection generally lags the true start of the received packet by δ seconds.
[0080] As introduced above, the input phy layer 344 also includes a carrier frequency corrector 344 . Generally, there is a difference between the local oscillator frequency f 0 tx at the transmitter, and the local oscillator frequency f 0 rx , and the carrier offset corrector essentially introduces a correction exp (−jβn), where β=2π(f 0 rx −f 0 tx )t s where t s is the sampling time of the sampler 340 . This correction effectively corrects for divergence of the oscillator frequencies over the duration of the received packet (i.e., it corrects the “rotating phase” exhibited during the packet). Note that if the oscillators are at the same frequency (although they may be at different phase) then no modification of the samples.
[0081] Each packet includes a number of known values modulated at different subcarriers. A channel estimator 346 reports the complex transformations CSI k of the known values to the demodulated values at subcarriers f k received after the carrier frequency corrector 344 . As discussed further below, the phases of the values CSI k depend on the propagation time τ, the packet detection delay δ, as well as an initial phase difference of the local oscillators at the time the packet was detected, and the magnitudes depend on the gain of the path (including amplification gain and over-the-air attenuation, etc.). Therefore the CSI k values cannot in general be used directly to estimate the propagation time τ alone, and therefore cannot be used directly to estimate the range between nodes. However, with appropriate processing described below, the CSI k values do yield an accurate range estimate.
2 Propagation Time
[0082] Before describing the details of how to determine channel phase ∠h i,0 at each of the carrier frequencies f i,0 for i=1, . . . , N, the approach to determining the range d from the phases is described in this Section. From basic electromagnetics, it is known that as a signal propagates in time, it accumulates a corresponding phase depending on its frequency. The higher the frequency of the signal, the faster the phase accumulates. To illustrate, let us consider a transmitter sending a signal to its receiver. Then we can write the wireless channel h as:
[0000] h=a exp(− j 2π f τ), (1)
[0000] where a is the (real valued) signal magnitude, f is the frequency and τ is the time of flight. The phase of this channel depends on time of flight as:
[0000] ∠ h =−2π f τ mod 2π (2)
[0083] Notice that the above equation depends directly on the signal's time of flight, and does not depend on the signal's precise time-of-departure at the transmitter. Hence, we can use Eqn. 2 above to measure the time of flight τ as:
[0000]
τ
=
-
∠
h
2
π
f
mod
1
f
(
3
)
[0084] The above equation gives us the time of flight modulo 1/f. Hence, for a single transmission at WiFi frequency of 2.4 GHz, we can only obtain the time of flight modulo 0.4 nanoseconds (ns). Said differently, transmitters with times-of-flight 0.1 ns, 0.5 ns, 0.9 ns, 1.3 ns, etc. would all produce identical phase in the wireless channel. In terms of physical distances, this means transmitters at distances separated by multiples of 12 cm (e.g., 3 cm, 15 cm, 27 cm, 39 cm, etc.) all result in the same channel phase. Consequently, there is no way to distinguish between these transmitters using the phase on a single frequency band alone.
[0085] As introduced above, the system makes use of multiple transmission bands, and hops between multiple frequency bands with carrier frequencies {f 1,0 , . . . , f N,0 } and measure the corresponding wireless channels {h 1,0 , . . . , h N,0 }. (For the remainder of this Section, the subscript 0 denoting the carrier frequency is omitted for brevity).
[0086] The result is set of constraints (e.g., a system of equations), one per frequency, that measure the time of flight modulo different values:
[0000]
∀
i
∈
{
1
,
2
,
…
,
N
}
τ
=
-
∠
h
i
2
π
f
i
mod
1
f
i
(
4
)
[0087] This set of equalities can be solved algebraically to determine τ modulo the Least Common Multiple (LCM) of {1/f 1 , . . . , 1/f N }. For instance, the system can resolve time of flight uniquely modulo 200 ns using WiFi frequency bands around 2.4 GHz. That is, a the system receiver can resolve transmitters within a radius of 60 m.
[0088] To illustrate how the above system of equations works, consider a transmitter at 0.6 m distance from a receiver, resulting in a time of flight of 2 ns. Say the receiver measures the channel phases from this source on five candidate WiFi frequency bands as shown in FIG. 4 . We note that a measurement on each of these channels produces a unique equation for τ, like in Eqn. 4. Each equation has multiple solutions, depicted as vertical lines in FIG. 4 . However, only the correct solution of τ will satisfy all equations. Hence, by picking the solution satisfying the most number of equations (i.e., the τ with most number of aligned lines in FIG. 4 ), we can recover the true time of flight of 2 ns.
[0089] Note that the solution makes no assumptions on whether the set of frequencies {f 1 , . . . , f n } are equally separated or otherwise. In fact, having unequally separated frequencies makes them less likely to share common factors, boosting the LCM. Thus, counter-intuitively, the scattered and unequally-separated bands of WiFi are not a challenge, but an opportunity to resolve larger values of τ.
[0090] Specifically, the procedure for computing τ modulo the LCM is as follows:
1. LCM←Least Common Multiple of {1/f 1 , . . . , 1/f N } 2. compute τ modulo LCM as
[0000]
τ
=
∑
i
(
-
∠
h
i
2
π
f
i
)
(
LCM
(
1
/
f
i
)
)
mod
LCM
(
5
)
=
LCM
∑
i
(
∠
h
i
2
π
)
mod
LCM
(
6
)
[0093] An alternative procedure for determining τ makes use of a sparse Fourier Transform. In situations in which there are indirect paths between the wireless nodes, for P indirect paths, the channels have the form h i =Σ p=0 P a i,p exp(−j2πf i τ p ). For the purpose of this computation, it is assumed that the magnitudes a i,p do not depend on the band i. A sparse Fourier Transform to find the peaks at τ 0 , . . . , τ P , with the smallest time τ 0 corresponding to the direct path, which is used to determine the range between the nodes.
3 Packet Detection Delay
[0094] In the discussion in this section, we assume that the frequency reference signals (e.g., local oscillator signals) at the transmitter and at the receiver are fully synchronized in frequency and phase, and the focus of this section is on mitigation of the effect of the delay in packet detection.
[0095] As discussed above, time of flight can be computed based on the channels h i (more specifically the phase of the channels) that signals experience when propagating over the air on different frequencies f i . In practice however, there is a difference between the channel over the air, h i , and the channel as measured by the receiver, {tilde over (h)} i . Specifically, the measured channel at the receiver, {tilde over (h)} i , experiences a delay in addition to time of flight: the delay in detecting the presence of a packet. This delay occurs because WiFi receivers detect the presence of a packet based on the energy of its first few time samples. The number of samples that the receiver needs to cross its energy detection threshold varies based on the power of the received signal, as well as noise. While this variation may seem small, packet detection delays are often an order of magnitude larger than time of flight, particularly in indoor environments, where time of flight is just a few tens of nanoseconds Hence, accounting for packet detection delay is very important for accurate time-of-flight and distance measurements.
[0096] The system therefore derives the true channel h i (which incorporates the time of flight alone) from the measured channel {tilde over (h)} i (which incorporates both time-of-flight and packet detection delay). To do this, the system exploit the fact that WiFi uses OFDM. Specifically, the bits of WiFi packets are transmitted in the frequency domain on several small frequency bins called OFDM subcarriers. This means that the wireless channels {tilde over (h)} i can be measured on each subcarrier. The approach described in more detail below takes advantage of the observation that the measured channel at subcarrier-0 does not experience packet detection delay, i.e., it is identical in phase to the true channel at subcarrier 0.
[0097] To see why this observation is true, note that while time-of-flight and packet detection delay appear very similar, they occur at different stages of a signal's lifetime. Specifically, time of flight occurs while the signal is transmitted over the air (i.e., in passband). In contrast, packet detection delay stems from energy detection that occurs in digital processing once the carrier frequency has been removed (in baseband). Thus, time-of-flight and packet detection delay affect the wireless OFDM channels in different ways.
[0098] To understand this difference, consider the WiFi frequency channel, i. Let {tilde over (h)} i,k be the measured channel of OFDM subcarrier k, at frequency f i,k . The channel {tilde over (h)} i,k experiences two phase rotations in different stages of the signal's lifetime:
a phase rotation in the air proportional to the over-the-air frequency f i,k . From Eqn. 2 above, this phase value for a frequency f i,k is
[0000] ∠ h i,k =−2π f i,k τ,
where τ is the time of flight. an additional phase rotation due to packet detection after the removal of the carrier frequency. This additional phase rotation can be expressed as:
[0000] Δ i,k =−2π( f i,k −f i,0 )δ i ,
where δ i is the packet detection delay; and
[0103] Thus, the total measured channel phase at subcarrier k is:
[0000]
∠
h
~
i
,
k
=
∠
h
i
,
k
+
Δ
i
,
k
(
7
)
=
-
2
π
f
i
,
k
τ
-
2
π
(
f
i
,
k
-
f
i
,
0
)
δ
i
(
8
)
[0104] Notice from the above equation that the second term Δ i,k =−2π(f i,k −f i,0 )δ i is zero at k=0. In other words, at the zero-subcarrier of OFDM, the measured channel {tilde over (h)} i,k is identical in phase to the true channel h i,k over-the-air which validates our claim.
[0105] In practice, this means that we can combine the phases and the derived modular time delay estimate (i.e., time delay modulo a constant) based on the the zero-subcarriers (i.e. center frequencies) of the channels on each of the WiFi frequency bands. In the U.S., WiFi at the 2.4 GHz and 5 GHz bands has a total of 35 WiFi channels with independent channel (i.e., center) frequencies. (Including the DFS bands at 5 GHz in the U.S. which are supported by many 802.11h-compatible 802.11n radios, e.g., the Intel 5300.) Therefore, a sweep of all WiFi frequency bands results in 35 independent equations which can be used to recover time of flight.
[0106] However, the channel of the zero subcarrier is not directly available. This is because WiFi transmitters do not in general send data on the zero-subcarrier, meaning that this channel simply cannot be measured directly at the receiver. (One reason that WiFi transmitters may not send data at the zero-subcarrier is that it overlaps with DC offsets in hardware, which can be difficult to remove.)
[0107] Rather than measure the channel of the zero subcarrier directly, the system makes use of the remaining WiFi OFDM subcarriers, where signals are transmitted. Specifically, it leverages the fact that indoor wireless channels are based on physical phenomena. Hence, they are continuous over a small number of OFDM subcarriers. This means that the system can interpolate and/or extrapolate the measured channel phase across all subcarriers to estimate the missing phase at the zero-subcarrier.
[0108] Although Eqn. 8 shows that ∠{tilde over (h)} i,k varies linearly with f i,k as k varies, a robust interpolation approach uses cubic spline interpolation (i.e., assuming a cubic relationship rather than linear relationship in f i,k to extrapolate to f i,0 ), however other approaches can be used. According to the the 802.11n standard a receiver measures wireless channels on as many as 30 subcarriers on each WiFi channel. Hence, interpolating between the subcarriers not only helps the system retrieve the measured channel on the zero-subcarrier, but also provides additional resilience to noise.
[0109] To summarize, the system applies the following steps to account for packet detection delay: (1) It obtains the measured wireless channels on the 30 subcarriers on the 35 available WiFi channels; (2) It interpolates between these subcarriers to obtain the measured channel phase on the zero-subcarriers on each of these channels, which is unaffected by packet detection delay. (3) It retrieves the time of flight using the resulting 35 channels using the approach described above.
4 Phase and Frequency Offset
[0110] To work with practical WiFi radios, the system also addresses inherent phase and frequency offsets in the local oscillators at the transmitter and receiver of a packet. These offsets include:
PLL Phase Offset: Frequency hopping causes a random phase offset in the measured channel. This is because the phase-locked loop (PLL) responsible for generating the center frequency for the transmitter and the receiver starts at random initial phase (say, φ i,0 tx and φ i,0 rx respectively). As a result, the channel measured at the receiver is corrupted by an additional phase offset φ i,0 tx −φ i,0 rx . This phase offset, if left uncorrected, could render the phase information uncorrelated with the time-of-flight of the signal; and Carrier Frequency Offset: This offset occurs due to small differences in the carrier frequency of the transmitting and receiving radio. This leads to a time varying phase offset across each frequency band. Such differences accumulate quickly over time and need to be corrected for every WiFi packet. Mathematically, in the i th WiFi channel, the receiver center frequency f i,0 rx is slightly different from the transmitter center frequency, f i,0 tx . As a result, the channel measurements at the receiver have an additional phase change which is proportional to f i,0 tx −f i,0 rx .
[0113] Let us refer to the channel values that incorporate phase and frequency offsets as CSI (Channel State Information), which is the typical term used in communication systems. Then, the CSI measured at the receiver for the i th frequency band can be written as:
[0000] CSI i,0 rx ( t )= {tilde over (h)} i,0 exp( j ( f i,0 tx −f i,0 rx ) t+j (φ i,0 tx −φ i,0 rx )) (9)
[0114] To mitigate the effect or phase and frequency offset, the system exploits the observation that the phase and frequency offsets measured on one node with respect to another change sign when measured on the second node with respect to the first. Thus, if one would measure the CSI on the transmitter with respect to the receiver, it would take the following value:
[0000] CSI i,0 tx ( t )= {tilde over (h)} i,0 exp( j ( f i,0 rx −f i,0 tx ) t+j (φ i,0 rx −φ i,0 tx )). (10)
[0115] Note that the channel, {tilde over (h)} i,0 , in equations 9 and 10 is the same due to reciprocity. We can therefore multiply the CSI measurements at the receiver and the transmitter to recover the wireless channel as follows:
[0000] {tilde over (h)} i,0 2 =CSI i,0 rx ( t )CSI i,0 tx ( t ) (11)
[0116] Measuring the CSI at the transmitter makes use of the fact that the nodes transmits packets back and forth to one another. Hence, the CSI can be measured on both sides and exchanged to apply Eqn. 11.
[0117] The above formulation provides the square of the wireless channels {tilde over (h)} i,0 2 , which has a phase that is double that of {tilde over (h)} i,0 . Therefore, using the squared channel in place of the channel to determine the modular times, which are combined over frequency bands yields twice the propagation delay.
[0118] In practice, the forward and reverse channels cannot be measured at exactly the same t but within short time separations (tens of microseconds), resulting in a small phase error. However, this error is significantly smaller than the error from not compensating for frequency offsets altogether (for tens of milliseconds). The error can be resolved by averaging over several packets.
[0119] A second observation is that delays in the hardware (e.g., due to wire lengths, component delays, etc., distinct from delay resulting from packet detection delay) result in a constant additive value to the time-of-flight. This constant is pre-calibrated once in the lifetime of a device, for example, by measuring time-of-flight to a device at a known distance.
5 Multipath
[0120] The discussion above has focussed on the nodes communicating directly, for example as illustrated in FIG. 1 on a path 110 . However, indoor environments are rich in multipath, causing wireless signals to bounce off objects in the environment like walls and furniture. In FIG. 1 the signal travels along indirect paths 112 A-B from its sender to receiver. The signals on each of these paths propagate over the air incurring different time delays as well as different attenuations. The ultimate received signal is therefore the sum of these multiple signal copies, each having experienced a different propagation delay. FIG. 5 shows a similar situation as shown in FIG. 1 . In this example, the most direct path, with propagation time of 5.2 ns is attenuated relative to indirect paths with times of 10 ns and 16 ns respectively.
[0121] Consider a situation in which wireless signals from a transmitter reach a receiver along p different paths. The received signal from each path corresponds to amplitudes {a l , . . . , a p } and propagation delays {τ 1 , . . . , τ p }. Observe that Eqn. 1 considers only a single path experiencing propagation delay and attenuation. In the presence of multipath, we can extend this equation to write the measured channel {tilde over (h)} 1,0 on the zero subcarrier (i.e., center-frequency) f i,0 as the sum of the channels on each of these paths, i.e.:
[0000]
h
~
i
,
0
=
∑
k
=
1
p
a
k
exp
(
-
j
2
π
f
i
,
0
τ
k
)
,
for
i
=
1
,
…
,
n
(
12
)
[0122] The system “disentangles” these different paths and recovers their propagation delays. To do this, notice that the above equation has a familiar form of a Discrete Fourier Transform. Thus, if one could obtain the channel measurements at many uniformly-spaced frequencies, a simple inverse-Fourier transform would separate individual paths. Such an inverse Fourier transform has a closed-form expression that can be used to obtain the propagation delay of all paths and compute the multipath profile (up to a resolution defined by the bandwidth).
[0123] WiFi frequency channels, however, are not equally spaced—they are scattered around 2.4 GHz and multiple non-contiguous frequency ranges at 5 GHz. While we can measure {tilde over (h)} 1,0 at each WiFi band, these measurements will not be at equally spaced frequencies and hence cannot be simply used to compute the inverse Fourier transform. In fact, since the measurements of the channels are not uniformly spaced, we are dealing with the Non-uniform Discrete Fourier Transform or NDFT. To recover the multipath profile, the system inverts the NDFT. An approach to the NDFT computation is provided in the Appendix.
[0124] Inverting the NDFT provides the system with the time of flight on all paths. The system still needs to identify the direct path so that it can compute the distance between transmitter and receiver. To do this, the system leverages the observation that of all the paths of the wireless signal, the direct path is the shortest. Hence, the time of flight of the direct path is the propagation delay corresponding to the first peak in the multipath profile.
[0125] It is worth noting that by making the sparsity assumption, we lose the propagation delays of extremely weak paths in the multipath profile. However, the system only needs the propagation delay of the direct path. As long as this path is among the dominant signal paths, the system can retrieve it accurately. Of course, in some unlikely scenarios, the direct path may be too attenuated, which leads to poorer localization in that instance. Our results (see, e.g., FIG. 8 ) depict the sparsity of representative multipath profiles, and show its impact on overall accuracy.
6 Results
[0126] An embodiment of the system was implemented as a software patch to the iwlwifi driver on Ubuntu Linux running the 3.5.7 kernel. To measure channel-state-information, the 802.11 CSI Tool for the Intel 5300 WiFi card was used. Channels on both 2.4 GHz and 5 GHz WiFi bands were measured. Note that the Intel 5300 WiFi card is known to have a firmware issue on the 2.4 GHz bands that causes it to report the phase of the channel ∠{tilde over (h)} i,0 modulo π/2 (instead of the phase modulo 2π). This issue was resolved by performing the system's algorithm at 2.4 GHz on {tilde over (h)} i,0 4 instead of {tilde over (h)} 1,0 . This does not affect the fact that the direct path of the signal will continue being the first peak in the inverse NDFT.
[0127] It should be understood that this implementation is just as example. Other implementations, which may use hardware, software, or a combination of hardware and software, may be used. The described procedures may be implemented in software, which includes instructions stored on a non-transitory machine-readable medium, and this software can control a processor at a node, or at a remote server, to perform the procedures. In addition, some of the functions may be implemented in hardware, for instance, using Application Specific Integrated Circuits (ASICs).
[0128] Unless specified otherwise, two the system devices (nodes) were paired by placing each device in monitor mode with packet injection support on the same WiFi frequency. The system's frequency band hopping protocol was implemented in the iwlwifi driver using high resolution timers (hrtimers), which can schedule kernel tasks such as packet transmits at microsecond granularity. Since the 802.11 CSI Tool does not report channel state information for Link-Layer ACKs received by the card, we use packet injection to create and transmit special acknowledgments directly from the iwlwifi driver to minimize delay between packets and acknowledgments. These acknowledgments are also used to signal the next channel that the devices should hop to. Finally, the channel state information was processed to infer time-of-flight and device locations purely in software written in part in C++, MEX and MATLAB.
[0129] The system's ability to measure the time-of-flight, and compute a client's position were evaluated using using a single access point. The system was tested using the testbed shown in FIG. 6 . The Figure shows a number of nodes, indicated by dots, distributed in a multiple room environment of approximately 20 meters square. In each experiment, a location for the access point was randomly picked, and then a client location that is within 15 meter from the access point was picked. Experiment with both line-of-sight and non-line-of-sight settings were conducted. The experiments were conducted using a 10″ ASUS EEPC netbook as a user device and a Thinkpad W300 Laptop emulating a WiFi access point via hostapd. Both devices were equipped with the 3-antenna Intel 5300 chipset. The antennas were placed at the corner of each device, which results an average antenna spacing of 30 cm for the Thinkpad access point and 12 cm for the ASUS client.
[0130] Using the above setup, 400 localization experiments were conducted for different AP-client pairs. For each pair, a channel hopping protocol was used to sample the different frequencies. The time of flight between each transmit antenna and receive antenna was computed using the techniques described above. The packet-detection delay of each packet using channel phase was also computed to gauge its effect on the measurement of time-of-flight.
[0131] The ground-truth location was determined using a combination of architectural drawings of the building and a Bosch GLM50 laser distance measurement tool, which measures distances up to 50 m with an accuracy of 1.5 mm. The ground truth time-of-flight is the ground truth distance divided by the speed of light.
[0132] Time-of-Flight Results: We first evaluate the system's accuracy in time-of-flight. FIG. 7 depicts the CDF of the time-of-flight of the signal in line-of-sight settings and non-line-of-sight. We observe that the median errors in time-of-flight estimation are 0.47 ns and 0.69 ns respectively. These results show that the system achieves its promise of computing time-of-flight at sub-nanosecond accuracy.
[0133] Multipath Profile Results: To examine whether multiple path profiles are indeed sparse, the candidate multipath profiles computed by the system were plotted. FIG. 8 plots representative multipath profiles in line-of-sight (LOS) and multipath (NLOS) environments. We note that both profiles are sparse, with the profile in multipath environments having five dominant peaks. Across all experiments, the mean number of dominant peaks in the multipath profiles is 5.05 with standard deviation 1.95—indicating that they are indeed sparse. As expected, the profile in a line-of-sight condition has even fewer dominant peaks than the profile in multipath settings. In both cases, we observe that the leftmost peaks in both profiles correspond to the true location of the source. Further, we observe that the peaks in both profiles are sharp due to two reasons: 1) the system effectively spans a large bandwidth that includes all WiFi frequency bands, leading to high time resolution; 2) the system's resolution is further improved by exploiting sparsity that focuses on retrieving the sparse dominant peaks at much higher resolution, as opposed to all peaks.
[0134] Packet Detection Delay Results: As described above, the system uses a novel way for separating the detection delay from the time-of-flight. FIG. 9 depicts histograms of both packet detection delay and time-of-flight across experiments. The system observes a median packet detection delay of 177 ns across experiments. We emphasize two key observations: (1) Packet detection delay is nearly 8×larger than the time-of-flight in our typical indoor testbed. (2) Packet delay varies dramatically between packets, and has a high standard deviation of 24.8 ns. In other words, packet detection delays are large, highly variable, and hard to predict. This means that if left uncompensated, these delays could lead to a large error in time-of-flight measurements. Our results therefore reinforce the importance of accounting for these delays and demonstrate the system's ability to do so.
[0135] The systems's accuracy in measuring distance and location using a single access point was also evaluated. The time-of-flight between the access point and user client was measured in the testbed as described. FIG. 10 plots the median and standard deviation of error in distance computed between the transmitter and receiver against their true distance. We observe that this error is initially around 10 cm and increases to at most 26 cm at 12-15 meters. The increase is believed due to reduced signal-to-noise ratio at further distances. Note that the ranging accuracy is higher than the localization accuracy because ranging is a more direct problem (no need to find the exact direction) and the system's time-of-flight computation naturally yields the range between devices.
[0136] FIG. 11 plots a CDF of localization error using the system in different settings. The device's median positioning error for line of sight scenarios is 65 cm and 98 cm in line-of-sight and non-line-of-sight. This result shows that the system's accuracy is comparable to state-of-the-art indoor localization that use multiple access points.
7 Applications
[0137] The approaches described above can be used in a variety of applications that can take advantage or accurate range measurements and/or accurate locatization based on accurate range measurements. Such applications can include:
Smart Home Occupancy: the system can be used to track the number of occupants in different rooms of a home using a single access point—a key primitive for smart homes that adapt heating and lighting. Experiments conducted in a 2-bedroom apartment with 4 occupants show that the system maps residents in a home to the correct room they are in with an accuracy of 94.3%; WiFi Geo-fencing: the system can be used by small businesses with a single access point to restrict WiFi connectivity to customers within their facility. Experiments in a coffee house reveal that the system achieves this to an accuracy of 97%; and Personal Drone: the system's ability to locate a pair of user devices can directly benefit the navigation systems of personal robots such as recreational drones. The system enables personal drones that can maintain a safe distance from their user by tracking their owner's handheld device. Our experiments using an AscTec Quadrotor reveal that it maintains the required distance relative to a user's device with a root mean-squared error of 4.2 cm.
[0141] It is to be understood that the foregoing description is intended to illustrate and not to limit the scope of the invention. Other embodiments are within the scope of the appended claims.
APPENDIX
Inverting the NDFT
[0142] The Non-uniform Discrete Fourier Transform (NDFT) is an under-determined system, where the responses of multiple frequency elements are unavailable. Thus, the inverse of such a Fourier transform does not have a single closed-form solution, but rather has several possible solutions.
[0143] The system solves for the inverse-NDFT by adding a constraint to the inverse-NDFT optimization. Specifically, this constraint favors solutions that are sparse. IN the context of ranging, such sparcity relates to there being few dominant signal paths. Intuitively, this stems from the fact that while signals in indoor environments traverse several paths, a few paths tend to dominate as they suffer minimal attenuation. In some examples, the sparsity of indoor multipath profiles in typical line-of-sight and non-line-of-sight settings is empirically evaluated.
[0144] The sparsity constraint mathematically is formulated as follows. Let the vector p sample inverse-NDFT at m discrete values τε{τ 1 , . . . , τ m }. Then, we can introduce sparsity as a simple constraint in the NDFT inversion problem that minimizes the L-1 norm of p. Indeed, it has been well-studied in optimization theory that minimizing the L-1 norm of a vector favors sparse solutions for that vector. Thus, we can write the optimization problem to solve for the inverse-NDFT as:
[0000] min∥ p∥ 1 (13)
[0000] s.t.∥{tilde over (h)}− p∥ 2 2 =0 (14)
[0000] where, is the n×m Fourier matrix, i.e. i,k =exp (−j2πf i,0 τ k ), {tilde over (h)}=[{tilde over (h)} i,0 , . . . , {tilde over (h)} n,0 ] T is the n×1 vector of wireless channels at the n different center-frequencies {f 1,0 , . . . , f n,0 }, ∥•∥ 1 is the L-1 norm, and ∥•∥ 2 is the L-2 norm. Here, the constraint makes sure that the Discrete Fourier Transform of p is {tilde over (h)}, as desired. In other words, it ensures p is a candidate inverse-NDFT solution of {tilde over (h)}. The objective function favors sparse solutions by minimizing the L-1 norm of p.
[0145] The above optimization problem is reformulated using the method of Lagrange multipliers as:
[0000]
min
p
h
~
-
ℱ
p
2
2
+
α
p
1
(
15
)
[0000]
Algorithm 1 Algorithm to Compute Inverse NDFT
Given: Measured Channels, {tilde over (h)}
: Non-uniform DFT matrix, such that = exp (−j2πf i,0 τ k )
α: SPARSITY parameter; ε: Convergence Parameter
Output: Inverse-NDFT, p
Initialize
p
0
to
a
random
value
,
t
=
0
,
γ
=
1
ℱ
2
.
while converged = false do
p t+1 =SPARSIFY(p t − γ *( p t − {tilde over (h)}),γα)
if ∥p t+1 − p t ∥ 2 < ε then
converged = true
p = p t+1
else
t = t + 1
end if
end while
function SPARSIFY(p,t)
for i = 1,2,...length(p) do
if |p i | < t then
p i = 0
else
p i = p i p i - t p i
end if
end for
end function
[0146] Notice that the factor α is a sparsity parameter that enforces the level of sparsity. A bigger choice of α leads to fewer non-zero values in p.
[0147] This objective function is convex but not differentiable. Our approach to optimize for it borrows from proximal gradient methods, a special class of optimization algorithms that have provable convergence guarantees. Specifically, our algorithm takes as inputs the measured wireless channels {tilde over (h)} at the frequencies {f i,0 , . . . , f n,0 } and the sparsity parameter α. It then applies a gradient-descent style algorithm by computing the gradient of differentiable terms in the objective function (i.e., the L-2 norm), picking sparse solutions along the way (i.e., enforcing the L-1 norm). Algorithm 1 summarizes these steps. the system runs this algorithm to invert the NDFT and find the multipath profile.
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A system enables a single WiFi access point to localize clients to within tens of centimeters. Such a system can bring indoor positioning to homes and small businesses which typically have a single access point. A key enabler underlying the system is a novel algorithm that can compute sub-nanosecond time of flight using commodity WiFi cards. By multiplying the time of flight with the speed of light, a Wifi access point computes the distance between each of its antennas and the client, hence localizing it. An implementation on commodity WiFi cards demonstrates that the system's accuracy is comparable to state-of-the-art localization systems, which use four or five access points.
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BACKGROUND OF THE INVENTION
The present invention relates to time controlled cigarette dispensing devices.
Cigarette dispensers of the character to which the present invention relates have been well known heretofore. Generally they include a housing within which there is provided means for storing a supply of cigarettes, means for serially dispensing the cigarettes, and control means for regulating the dispensing of the cigarettes at some predetermined series of delayed time intervals. A typical device is disclosed in U.S. Pat. No. 3,206,957 issued Sept. 21, 1965 to J. Reitzes. Another device of similar character in which the container is provided with a time controlled locking mechanism allowing access to the contents of the container only at predetermined times is disclosed in U.S. Pat. No. 3,750,435 issued Aug. 7, 1973 to Giora Belkin.
It is believed that cigarette dispensing devices of the type whereby cigarettes are dispensed in accordance with a predetermined timed sequence, but where the device remains unlocked and is accessible between the dispensing intervals, is most preferable for psychological reasons. Prior devices of the type powered by an electric motor have been so constructed as to be continuously in operation and have also been relatively complex. Thus, the constant drain on the device's battery has necessitated frequent replacement whereas constructions requiring multiple gearing, for example, have been costly to produce. These factors appear to be two primary reasons why time controlled cigarette dispensers have not been as commercially successful to date as had been anticipated. However, due to the increasing awareness by the general public of the serious health hazards presented by smoking it is of crucial importance that a device of the character described be made available to the public which is not encumbered by the failings of prior devices.
SUMMARY OF THE INVENTION
It is a primary object of the invention to provide a time controlled cigarette dispenser which is reliable and which requires being powered only during the dispensing cycle.
It is another object of the invention to provide a time controlled cigarette dispenser of simple construction and with relatively few moving elements.
Other objects and advantages of the invention will become readily apparent from the following description of the invention.
According to the present invention there is provided a time controlled cigarette dispenser comprising in combination: a housing; a downwardly inclined cigarette transfer tray mounted within the housing having a lower discharge end; a feeder ramp mounted pivotally within the housing having an upper cigarette-receiving end positioned adjacent to and cooperable with the discharge end of the transfer tray; spring means adapted to bias the feeder ramp and enable the feeder ramp and transfer tray to act cooperably to serially transfer cigarettes from the tray to the ramp; cigarette retainer means mounted resiliently in the housing adjacent the discharge end of the feeder ramp for controlling the discharge of cigarettes therefrom; a rotatable member having at least one compartment thereon and adapted to be rotated at a predetermined rotational speed to thereby cyclically position the one compartment beneath the discharge end of the feeder ramp to receive a cigarette therefrom and to deliver said cigarette to a balance tray; a balance tray pivotally mounted in the housing and adapted to receive a cigarette from the one compartment and to present same to the smoker; electric motor means for driving the rotatable member at the predetermined rotational speed and control means therefor; and means carried by the balance tray for deactivating the motor upon the deposit of a cigarette upon the tray and for activating the motor upon the removal of the cigarette therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more fully understood it will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a perspective view, partly broken away and partly in cross-section, showing a time controlled cigarette dispenser embodying the invention;
FIG. 2 is a schematic diagram showing the interrelationship between the balance tray and electric motor of the device of FIG. 1;
FIG. 3 is a side elevational view, partly in cross-section, of the device shown in FIG. 1;
FIG. 4 is an enlarged view of the feeder ramp, transfer tray, rotatable member and cigarette retaining means shown in FIG. 3; and
FIG. 5 is a view similar to FIG. 4 showing a modified arrangement of such elements.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings there is shown generally a time controlled cigarette dispenser 10. The dispenser includes a housing 12 within which there is located the working elements of the device.
Mounted within the housing is a downwardly inclined cigarette transfer tray 14 which may conveniently be secured to an internal partition 16 that is mounted on a side wall 18 of the housing. The transfer tray desirably is given a flat upper surface 20 and is shown as terminating in a lower discharge end which is in spaced relation to side wall 18 of the housing. Thus, a supply of cigarettes may be stored on the tray for ultimate dispensing to the smoker.
A feeder ramp 24 is positioned beneath the transfer tray and is pivotally mounted such as by means of a pivot pin 26. For a reason which will become clear, the feeder ramp is pivotally mounted about its pivotal axis such that its upper cigarette-receiving end 28 is closer thereto than the lower discharge end 30. A fine coil spring 32 is secured to the feeder ramp so as to bias the uper end thereof away from the discharge end of the transfer tray to thereby permit the discharge of a cigarette therefrom. It will be recognized that upon the discharge of a cigarette from the transfer tray to the receiving end of the feeder ramp it will roll down the feed ramp and effectuate a pivotal movement of the feeder ramp such that the upper end is brought into abutting relation with the discharge end of the transfer tray to prevent the discharge of another cigarette until the cigarette already stationed on the feeder ramp is discharged. The dimensions of the levers, into which the feeder ramp is divided by the pivot pin, are predetermined to permit the development of a force moment at the discharge end of the ramp when a cigarette is positioned there at which is sufficient to overcome the force of coil spring 32 in order to effectuate the pivotal movement of the feeder ramp to block the transfer of a cigarette from the transfer tray.
At least one retaining element 34 is mounted in the housing adjacent the discharge end of the feeder ramp and is biased by spring means 36, which may either be a coil spring or flat spring, to block the discharge of a cigarette stationed for discharge on the feeder ramp.
A rotatable member 38 is mounted rotatably within the housing and preferably takes the form of a circular disk. For convenience it may be connected by means of a plurality of spoke members 40 with a second disk 42. Both of such disks are drivably connected, such as by means of a central shaft 44, with an electric motor 46. The motor may be any suitable electric motor which can be fitted with a speed reducer (not shown) or speed regulator (not shown) so as to afford the desired range of driving speeds for the rotatable member. Extremely slow speeds are most desirable so that the rotatable member is adapted to withdraw from the feeder ramp a cigarette at timid intervals as may be considered appropriate in order to gradually decrease the smoker's dependence upon cigarettes. A recommended range of rotational speeds for the rotatable member is such as to permit the withdrawal of a cigarette every thirty minutes to the withdrawal of a cigarette every two hours.
The rotatable member may comprise a single disk of sufficient axial extent to support a cigarette received from the feeder ramp. It will be seen that the peripheral surface of the rotatable member is formed with at least one compartment 48 therein adapted to receive and support therein in axial relationship to the rotatable member a cigarette discharged from the feeder ramp. Preferably two or more of such compartments are formed in spaced relation about the periphery of the rotatable member. As viewed in FIG. 1 of the drawings, the rotatable member is rotated in a clockwise direction so that one of the compartments is cyclically positioned beneath the discharge end of the feeder ramp to receive a cigarette therefrom.
As shown in the drawings the compartments may simply consist of one or more recesses formed in the periphery of the rotatable member. It will be observed that a cam projection 50 is formed on the rotatable member adjacent to and in advance of each of the compartments. The purpose of the cam projection is to engage with the retaining element 34 to force same away from the discharge end of the feeder ramp to thereby permit the discharge of the cigarette stationed thereat. Thus, after the rotatable member has rotated to a position where cam 50 is no longer engaged with the retaining element the spring 36 will return the retaining element to close proximity with the discharge end of the feeder ramp to prevent the discharge of another cigarette until the next succeeding cam projection engages the retaining element to force it away from the feeder ramp.
As may be seen most clearly from FIGS. 2 and 3, a balancing tray 52 is mounted pivotally in the housing at the bottom thereof such as by means of a pivot pin 54. The tray is thus divided into a cigarette receiving lever segment 56 and a lever segment 58 which carries electrical contact means 60 cooperable with electrical contact means 62 in the motor circuit. It will thus be seen that when a cigarette is deposited upon segment 56 from one of the compartments of the rotatable member 38 the balance tray is caused to pivot about the pivot pin 54 to thereby break the electrical connection between contact means 60 and 62. The electric motor is thereby deactivated. However, upon the removal of the cigarette from the balancing tray by the smoker the tray is caused to pivot back to its original position to reestablish the electrical connection between the contact means 60 and 62 and thereby reactivate the electric motor. In this manner the operation of the electric motor is made continuous only during the dispensing cycle. Once the cigarette has been transferred to the balancing tray for presentation to the smoker there is no longer any need to keep the motor running. If desired, and in order to accelerate restoration of the balancing tray to its original position in which the contact means 60, 62 are electrically connected it may be desirable to provide a light restoring spring which exerts sufficient force upon the tray to cause the tray to speedily pivot to its original position. Such spring (not shown) should possess a sufficiently low strength as to enable a cigarette at the end of segment 56 to effectuate pivotal movement of the tray into the position shown in FIG. 2 where the motor circuit is broken.
A modification of the arrangement shown in FIG. 4 is depicted in FIG. 5 where a spring 64 is secured to the feeder ramp for the purpose of biasing the receiving end of the feeder ramp 24 into abutting relation with the discharge end of the transfer tray 14 so as to block the discharge of a cigarette therefrom. A second cam projection 66 is formed on the rotatable member 38 immediately to the rear of each compartment. Cam 66 is given a rise less than that of cam 50 such that when the member 38 rotates there will be no engagement of the retaining element by cam 66. The rise of cam 66 should, however, be sufficient to engage with the lower surface of the discharge end of the feeder ramp to effectuate pivotal movement of the feeder ramp against the force of spring 64. Such pivotal movement of the feeder ramp results in an opening of a passage between transfer tray 14 and the upper end of the feeder ramp to permit the transfer of a cigarette from the transfer tray to the feeder ramp from which point of the ramp it will roll downwardly until arrested by the retaining element as described above in conjunction with FIG. 4. The slope of cam 66 is dimensioned relative to that of cam 50 in order to insure that the cigarette transferred from tray 14 will roll down the ramp and be discharged therefrom together with the preceding cigarette. There must be adequate time for cam 50 to pass and release the retaining element so that it blocks the discharge of the second cigarette.
From the foregoing it will be seen that an improved time controlled cigarette dispenser has been provided which affords advantages not possible with prior devices of the same character. The availability of the device of this invention is expected to furnish valuable assistance in the drive to curtail cigarette smoking.
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A time controlled cigarette dispenser includes a pair of cooperable superposed inclined surfaces for serially transferring cigarettes from the upper surface to the lower surface. A rotatable drum receives the cigarettes serially in a predetermined timed sequence from the lower surface and delivers it to a pivotable balance tray from when the smoker may retrieve it for smoking. The drum is motor driven, and upon the deposit of a cigarette on the balance tray the motor is deactivated. Upon retrieval of the cigarette from the balance tray the motor is activated to transfer another cigarette thereto.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to subject matter found in co-filed applications “BOOK COVER AND USES” to James M. Devoy et al., Ser. No. ______ (95344), and “A BOOK AND A METHOD OF MAKING SAME” to Joseph Manico et al., Ser. No. ______ (95408).
FIELD OF THE INVENTION
[0002] The present invention relates to a system, apparatus, and method for constructing books using hard and soft book covers having an adhesive strip for binding media. The books can be made by an unskilled user to bind any media into a finished and functional book format.
BACKGROUND OF THE INVENTION
[0003] It is known to assemble books and photo albums from media of single- and double-sided printed documents and photographs. Traditional bookbinding methods included gluing and/or stitching a set of pages together along one edge. This bound edge was then attached to a book cover, either directly, or through attachment to a spine sheet. A spine sheet spanned the spine of the cover without being attached to it, and was adhered only to the two sides of the cover. The spine sheet allowed a user to fully open a finished book because it would flex separately from the spine of the cover. A hot glue method, traditionally an animal glue, or today a synthetic adhesive, typically binds the bound edges of the manuscript to the spine sheet or cover, and is used to bind the spine sheet to the cover.
[0004] Today there is a prolific variety of printing technologies, for example, traditional photographic, inkjet, electrophotographic, laser, hot wax transfer, thermal dye sublimation, and thermal ablation, in addition to traditional printing technologies of gravure, typeset, manual manuscript illustration, intaglio, woodcut, etching, stamping, in-mould printing, flexography, screen printing, and others, any of which can be used for home, retail, or commercial applications. Each one of these technologies produces its own range of printed output with different media types, stocks weights, sizes, formats, thicknesses, and surface finishes. Each also has different hygroscopic properties and chemical sensitivities, making binding of different media types together a technical challenge.
[0005] Today, more people print at home, or in a retail setting, such as in a grocery store, drug store, or specialty retailer. There is also a growing movement again in specialty, small-print presses. Such non-traditional book-makers, specialty presses and the home user, like to experiment with binding different types of materials together, and expect an easy-to-use process for binding materials.
[0006] Some commonly available binding systems for binding standard media types and sizes require modifying the media by perforating it to accommodate clamp- and ring-type binders. Alternatively, special media that is already perforated can be used. Clamp- and ring-type binders do not have the appearance and function of conventional soft or hard covered books. Further, a user has to ensure the perforations appear in the margins and do not obscure images or type on the media.
[0007] Many people now combine media to form scrapbooks centered around photographic images. Alternately, traditional photobooks are still desired by many. Different means of allowing the home user and retailer to easily assemble such books have been developed.
[0008] For example, the bindings system disclosed in U.S. Pat. No. 6,742,809 B2 “Photo Album Constructed From A Strip Of Images,” by Frosig et al., assigned to Eastman Kodak Company, shows how a continuous strip media format is used to form a set of pages for a photo album. The pages are interconnected by means of fan folding and adhesively binding a printed continuous media strip so that the pre-formed bundle will bond to a cover with a conventional pressure sensitive adhesive. Because there are no loose pages, individual pages can not become dislodged from the conventional pressure sensitive adhesive on the cover spine. In addition, the end sections of the adhesive covered continuous fan-folded strip can be used to attach to and reinforce front and back book covers, if desired, increasing the strength of the overall bond.
[0009] Many printers can not print on continuous strips of media and special formatting would be required for the information and/or images to be properly aligned with the fan folded pages. In addition, some printing technologies do not work well with adhesive coated media, which is required to attach the inner surfaces of the fan folded pages. Alternately, a user would have to apply the adhesive manually. In order to properly align and fold a continuous length of media, the media must be pre-scored, pre-creased, or pre-perforated in order to facilitate proper construction of the fan-folded page bundle. If a continuous length of media is not modified by the media manufacturer, equipment to perform these media modifications pre- or post-printing would be required by the user. Equipment of this type is readily available but requires time, user skill, and, if improperly used, can damage a finished print rendering it useless.
[0010] Another system for binding standard document types uses preformed hard or soft book covers with thermally activated adhesive pre-deposited along the inner surface of the book cover spine. This system requires binding equipment to apply heat and pressure to a special cover once the desired media is in place. The equipment clamps the media in place against the adhesive on the spine while it melts the adhesive. After the adhesive is melted, the bound book must be left to cool in order for the adhesive to set and adhere the pages to the cover spine. This method requires energy, heat, and significant time to produce the final product. In some systems, the cover and media must remain clamped during the cooling process. This method is not suitable for all media, for example, plastic sheets, thermal dye sublimation and electrophotography prints, and other prints sensitive to the high temperatures required to activate the thermal adhesive. This temperature sensitivity could result in damaged media or could affect the quality of the printing. In addition, once bonded, the solidified thermal adhesive lacks flexibility, which prevents the pages from laying flat and makes it difficult to hold the book open and turn the pages.
[0011] A supposedly more user-friendly system, US20080093836 A1, “Activation And Deactivation Mechanisms For Media Binders,” by Hoarau et al., describes a clamp-type binder that provides a simple, equipment free, instant binding solution wherein the clamping mechanism is built into a preformed binder. The clamp is deployed by using the rigid book cover, bent backwards as a deployment lever, to open the clamp. The pages in this binder type are held in a tight bundle and can not lay flat. In addition, the binder must have a hard cover in order to act as a lever for the clamp, and does not maintain the appearance and function of a conventional book. However, this book allows removal and addition of pages by a user after formation.
[0012] U.S. Pat. No. 5,716,181 “A One Piece Self-binding System for Binding Documents,” Ebel, like US20080093836 A1, discloses a pressure clamping mechanism built into the spine of a preformed binder. In this approach, however, a metal strip is used to keep the spring clamp opened until the media is placed in position. A pull ring is used to pull the strip free, allowing the clamp to close on the media. It is very difficult to re-open the clamp, making the book contents relatively permanent. U.S. Pat. No. 5,061,139 “Method for Applying Hard and Soft Covers to Bound or Unbound Documents,” by Zoltner, describes a similar system where a U-shaped channel is bound into the spine of soft or hard covers, and the channel is crimped over the media to hold it in place.
[0013] Another known approach to providing a book binding system is demonstrated by GB2316358 A, “Album for adhesively binding a stack of pictures,” by Paul Druckerei Kieser. This method is similar to conventional bookbinding methods. This system has a pressure sensitive adhesive coated on a flexible paper substrate that is attached to a book cover, as illustrated in FIGS. 1 a and 1 b . The adhesive photo print binding system 10 of Kieser has a cover 20 creased 60 at the edges of the spine 65 to allow the book cover 20 to open and close. The cover 20 has a flexible substrate 30 attached to the front and back inside edges of the cover 20 by an adhesive 50 over the spine 65 , which is shown in more detail in inset 40 , shown in FIG. 1 b . The flexible substrate 30 is not attached to the book spine 65 , and forms a floating spine section 90 . A pressure sensitive adhesive 80 and an adhesive release layer (not shown) cover the flexible substrate in the area directly over the book cover spine, facing away from the book spine. A user must remove the release layer and expose the pressure sensitive adhesive to attach a stack of photographs 70 to the adhesive 80 . The user must carefully align the stack of photographs with the adhesive before final placement. In addition the user must slide and press the external edge of the book spine across a sharp edge in order to set the pressure sensitive adhesive. This technique, along with the initial alignment process, both rely on the rigidity that a stack of heavy stock photographic media provides. The user must align and attach the stack of photographs to the exposed adhesive in a single action. Other less rigid medias, such a plain paper, would be difficult to align and push into the exposed adhesive as required. Once assembled, the flexible substrate deforms when the finished book is opened to compensate for stress on the page edge contact bond as the pages of the book are turned. Because the flexible substrate is not attached at the spine, the stress from the weight and movement of the pages is concentrated at the points where the flexible substrate is attached to the front and rear of the book cover. These stress point are prone to tearing. Further, because only the edges of the individual pages contact the thin layer of pressure sensitive adhesive, pages are prone to detach and fall out of the book.
[0014] There is a need in the industry of book making for a system, method and book whereby the book is easily assembled by an unskilled user using user-selected media, and wherein the book retains the media with sufficient force to prevent loss of media over time or during use.
SUMMARY OF THE INVENTION
[0015] A system for binding media is disclosed, wherein the system includes a cover capable of accepting media, wherein the cover includes a front cover, a back cover, and a spine section therebetween, wherein an adhesive strip is adhered to the spine, with the side of the adhesive strip opposite the spine having a release strip removably attached. The adhesive strip has a peak load gram force per inch of at least 200 and a thickness of at least 0.1 mm. One or more adhesive strip can be used in the spine section. The spine section can be selectable in width. Optional system features can include one or more media clamp, a coating material for adhesion to the adhesive strip, and a media stack corresponding in size to the cover.
Advantages
[0016] The system, method, and book cover described herein are easily understood and used by an ordinary person, without skill in the bookmaking industry. The assembled book provides a quality product that is neat, retains media over time and with extended use, and allows for full viewing of each inserted media edge-to-edge. The system, method, and book cover can be used with various media, and can be used with mixed media, to form a permanent product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Throughout the specification, reference is made to the accompanying drawings:
[0018] FIG. 1 a is plan view illustration of a prior art adhesive photo print binder;
[0019] FIG. 1 b is close up plan view illustration of the spine section of the prior art adhesive photo print binder of 1 a;
[0020] FIG. 2 a is a plan view of a book cover with a selectable spine width section;
[0021] FIG. 2 b is a side view of the book cover of FIG. 2 a;
[0022] FIG. 3 a is a plan view of a book cover and adhesive tray spine with gel adhesive according to one embodiment of the present invention;
[0023] FIG. 3 b is a plan view of a book cover with an adhesive impregnated foam strip according to another embodiment of the present invention;
[0024] FIG. 3 c is a plan view of a book cover with a cast get adhesive strip according to another embodiment of the present invention;
[0025] FIG. 3 d is a plan view of a book cover with an adhesive strip in a flush spine section;
[0026] FIG. 4 a is a sectional axial view of the book cover of FIG. 3 a;
[0027] FIG. 4 b is a sectional axial view of the book cover of FIG. 3 b;
[0028] FIG. 4 c is a sectional axial view of the book cover of FIG. 3 c;
[0029] FIG. 4 d is a sectional axial view of the book cover of FIG. 3 d;
[0030] FIG. 5 a is a side view of an adhesive strip with a top and bottom release strip;
[0031] FIG. 5 b is a side view of an adhesive strip with two release strips;
[0032] FIG. 6 a is a plan view of a book cover with two adhesive strips side-by-side;
[0033] FIG. 6 b is a side view of the book cover of FIG. 6 a;
[0034] FIG. 6 c is a plan view of a book cover with two adhesive strips end-to-end;
[0035] FIG. 7 a is a plan view of a V-folded page with optional perforations on the fold line;
[0036] FIG. 7 b is a plan view of the V-folded page of FIG. 7 a with the pages closed;
[0037] FIG. 8 is a side view illustrating adhesive perforation of a perforated medium;
[0038] FIG. 9 a is a plan view of a book cover with optional media clamps;
[0039] FIG. 9 b is a side view of the book cover of FIG. 9 a;
[0040] FIG. 10 a is a plan view of a book cover and an unattached media bundle;
[0041] FIG. 10 b is a plan view of a book cover with a media bundle in place against the adhesive strip with attached release strip;
[0042] FIG. 11 is a plan view of a closed book cover with media clamps and inserted media bundle;
[0043] FIG. 12 is a plan view of a closed book cover with media clamps and the removed release strip;
[0044] FIG. 13 a is a sectional side view of a book cover and an unattached media bundle against the adhesive strip with attached release strip;
[0045] FIG. 13 b is a sectional side view of a book cover with a media bundle in place and the release strip partially removed, exposing part of the adhesive strip;
[0046] FIG. 13 c is a sectional side view of a book cover with the release strip removed, and the media bundle adhered to the adhesive strip;
[0047] FIG. 14 is a plan view of a closed book cover with an attached media bundle and removed media clamps;
[0048] FIG. 15 is a plan view of application of a coating material to the adhesive strip of a finished book; and
[0049] FIG. 16 is a plan view of an opened finished book cover showing the attached media bundle pages opened to form a single viewing plane.
[0050] The drawings are illustrative only, and are not to scale. Other embodiments and relations between the parts are envisioned, as explained in the Detailed Description.
DETAILED DESCRIPTION OF THE INVENTION
[0051] A book cover capable of accepting media, a system for forming a book, and a method of forming a book are described with reference to the Figures, which are exemplary only. Like numerals are used for like structures throughout the figures. As used herein, reference to a singular (for example, “cover,” “strip,” etc.) item or action are meant to also include the plural unless such an embodiment would be inoperative. Similarly, plural forms (for example, “covers,” “strips,” etc.) do not exclude use of a singular of the item or action.
[0052] The book cover can be of any media. Book covers are typically categorized as hard or soft covers, based on media choice. It can be desirable to choose a media that is wear resistant, such that the book cover will endure throughout extended handling, opening and closing, and exposure to various environmental conditions over time. Examples of materials include, but are not limited to, cardboard, paperboard, plastic, paper, any type of animal skin, metal, metallic coated materials, and fabric. The book cover can include a section for insertion of a photograph, paper, memento, or other object on the front cover. Book cover styles as are known for the printing industry, photographic albums, and specialty art book collections can all be used. The book cover, or at least a portion thereof, can be printable by any means, for example, thermal printing, ink jet, laser printing, clectrophotographic, or other methods, or writable.
[0053] The book cover can be the same dimensions as the media to be inserted. If it is desirable to have at least some of the media exposed, such as tabbed pages, when the book cover is closed, the book can be narrower than at least some of the media, shorter than at least some of the media, or both. To best protect the media, the book cover can be wider than all the media, longer than all the media, or a combination thereof.
[0054] The book cover can have a front cover and a back cover joined by a spine section. Typically, the front cover, back cover, and spine section are contiguous, made from a single sheet of material. However, the spine can be different from one or more of the front and back cover, and attached by any known means, including stitching, binding, gluing, stapling, or other methods, either directly or through an intermediary material that can form a spine crease, wherein the spine crease is a flexible section between the spine and front cover or back cover.
[0055] A book cover can have multiple pre-formed spine creases, or at least indicators of where a spine crease could be placed by a user in the spine section, as shown in FIGS. 2 a and 2 b . In FIGS. 2 a and 2 b , a book cover 100 has a spine section 65 with flexible spine creases 60 which are indicated to a user by spine crease indicators 62 . This allows for user selection of the width of the spine section 65 to accommodate the full collection of whatever media is being inserted into the book cover 100 . Without a spine crease 65 selection, the appropriate book cover must be chosen to accommodate the width of the media to be inserted. The spine crease indicators 62 to select the width of the spine can include one or more crease, perforation, score mark, depression, line, or other visual or tactile indicator.
[0056] The entire spine section can be a very flexible material, or can include numerous pre-formed creases, perforations, score marks, or other means of increasing flexibility over the entire spine section. This enables the entire spine section to flex with the opening and closing of the book, the movement of pages, or both. If the entire spine section is flexible, any media inserted that is no thicker than the total width of the spine section can be used without the additional need to select a spine crease area, because the spine crease will naturally occur in a flexible spine section just beyond the media.
[0057] The book cover has an outside, viewable by the user when the cover is in a closed position, and an inside, viewable by the user when opened. On the inside of the spine section, the book cover can have one or more adhesive strip. A single adhesive strip can be used where there is a pre-defined, definite spine width. Alternately, multiple adhesive strips can be used to span the width, the height, or both of the spine. The adhesive strip(s) can be pre-attached to the book cover at the time of manufacture, or before sale. Alternately, the adhesive strip(s) can be attached by the purchaser (user), or at the retail location once the user has selected a book cover and adhesive.
[0058] The spine section can be flush or nearly flush with the book cover when the book cover is opened flat, or the spine section can extend from the front and back book cover section, forming a depression, channel, or tray-shaped spine section. The extended spine section can have two or more side portions, and a back portion, wherein the back portion can be flat or curved. An extended spine section allows for insertion of a thicker adhesive strip without concern for adhesion to the front and back book cover or spine creases, particularly where the adhesive strip is the full width of the spine section.
[0059] In alternative embodiments, a floating spine as known in the prior art can be used inside the cover over the spine section, and one or more adhesive strip can be attached to the inside of the floating spine for insertion of media. The floating spine is not necessary. Use of the floating spine with the adhesive strip provides a more secure insertion of the media into this pre-existing book cover format.
[0060] An adhesive strip is a piece of adhesive material suitably shaped to fit into the book cover spine section, and to hold the intended media for insertion. The term “strip” is not meant to imply any particular shape, as the adhesive material can be any geometric or irregular shape. The adhesive strip should have a thickness sufficient so that the media to be inserted in the book cover embeds into at least a portion of the adhesive strip. This enables better adhesion of the inserted media because more than the edge of the media is in contact with the adhesive strip. The media will have the edge and a portion of each side of the media in contact with the adhesive strip, increasing the adhesion force. For example, the adhesive strip can be at least 0.1 mm thick, although thinner adhesive strips may be acceptable if they allow embedding of the media. In some embodiments, the adhesive strip can be between 0.1 mm and 5 mm thick, although thicker or thinner adhesive strips can be used.
[0061] The adhesive strip can be sufficiently adhesive that an inserted medium can not be pulled from the adhesive. Also, the adhesive strip should not stretch significantly, for example, no more than three times its thickness. Excessive stretching can weaken the adhesive strip, and may allow the inserted media to be damaged. The adhesive strip can have a peak load gram force per inch of about 200 or greater. A lower peak load gram force per inch may be acceptable if other adhesive strip characteristics as described herein are met.
[0062] Examples of adhesive strips suitable for use herein include impregnated foamed adhesives, gel adhesives, and cast adhesive strips. The adhesive strip can be formed by casting into a tray or form, casting onto a release layer, or forming an open or closed cell foam from adhesive, or impregnating an open or closed cell foam with adhesive. Unlike conventional single- and double-sided tapes which have a thin coating of pressure sensitive adhesive affixed to one or two sides of a non-adhesive liner, or coated directly onto an adhesive release film, foamed, gel, and cast adhesives are adhesive throughout the thickness of the material. The adhesive material, once formed, has a release sheet on at least one side thereof, and the material is typically cut to shape for sheets, or rolled and slit to desired widths. Because these adhesive types do not include a supportive liner, and are flexible throughout the thickness of the adhesive material, they are more flexible and elastic than conventional single- and double-sided tapes. This allows the media for insertion to be embedded within the adhesive material, as opposed to being adhesively attached to only the surface layer, as with conventional single- and double-sided tapes. Embedding the media allows for secure media attachment while allowing the resultant book pages to move freely, and enables a lay-flat page presentation.
[0063] Gel, cast, and foamed adhesive strips have heretofore been used in such industries as pest removal for trapping of mice, rats and other vermin, and for attachment of heavy objects to walls or other surfaces, including rough surfaces such as stucco or brick, either inside or outside. Examples of specific adhesive strips include apeTape™ Adhesive Tapes (Essex, UK), such as JELLY® double-sided Very High Bond Tape and 3M 4905 VHB Double-Sided Tape Clear Acrylic Adhesive, and 3M™ SCOTCH® Exterior Mounting Tape 4011 and VHB™ Tapes, both adhesive and foam. Other adhesive strips having the characteristics described herein, whether commercially available or specialty products, can also be used.
[0064] The adhesive does not need to be exactly as wide as the spine section of the book cover, and preferably is a little narrower, not extending into the flexible spine creases. This is exemplified in FIGS. 3 a - d and 4 a - d . FIGS. 3 a and 4 a are plan and side views, respectively, of a book cover 100 having a channel or tray-shaped spine section 65 bounded by spine creases 60 , and having a gel adhesive 110 in a gel adhesive containment tray 120 in the spine section 65 . FIGS. 3 b and 4 b are plan and side views, respectively, of a book cover 100 having a channel or tray-shaped spine section 65 bounded by spine creases 60 , and having an adhesive impregnated foam strip 130 in the spine section 65 . FIGS. 3 c and 4 c are plan and side views, respectively, of a book cover 100 having a channel or tray-shaped spine section 65 bounded by spine creases 60 , and having a cast gel adhesive strip 140 in the spine section 65 . FIGS. 3 d and 4 d are plan and side views, respectively, of a book cover 100 having a flush or nearly flush spine section 65 bounded by spine creases 60 , and having an adhesive strip 145 in the spine section 65 . Multiple adhesives strips can be used to substantially cover the spine section in width or length. The adhesive strip, or combination of multiple adhesive strips, should be as wide as, or slightly wider, and as long as, or slightly longer, than the media stack or bundle to be inserted, such that ever medium in the bundle is embedded in the adhesive strip. Shorter adhesive strips can be used to ensure the adhesive strip is not exposed at the ends of the media stack in the book cover, if desired.
[0065] The adhesive strip can have one or more release strip attached thereto. The term “strip” does not imply a specific shape, and the release strip is a material releasably adhering to and cut to the relative shape of the adhesive strip. The release strip is removably attached to the adhesive strip, and is removed by a user to expose the adhesive strip for attachment to the book cover spine or the media for insertion. The release strip can slide easily along the media to be inserted. The release strip can slide easily along the spine of the book cover. The release strip desirably is very flexible, and has a low coefficient of friction, for example, of about 0.5 or lower, although a higher coefficient of friction may be acceptable in some circumstances, so long as the release strip can be removed from between the adhesive strip and either the spine section of the book cover or the media without tearing. The release strip can be longer than the adhesive strip, wider than the adhesive strip, extend beyond at least a portion of the adhesive strip, or some combination thereof. The extension of the release strip beyond the adhesive strip enables the user to grasp the release strip easily for removal from the adhesive strip. The portion of the release strip extending beyond the adhesive strip can be a doubled-over portion of the release strip, wherein the release strip is folded into a V-shape, with one arm of the V-shape extending beyond the adhesive strip. The V-shape configuration of the release strip allows the release strip to be removed from the adhesive strip with a low pull force because the direction of pull is close to 180 degrees as the release strip is pulled from between the adhesive strip and the media, or from between the adhesive strip and the book cover spine. This is demonstrated in FIG. 5 a , wherein adhesive strip 145 has a top and a bottom release strip 160 , wherein each release strip 160 extends along the full length of adhesive strip 145 , then doubles back for the full length of the adhesive strip 145 and release strip section attached to the adhesive strip 160 , and extends beyond the adhesive strip 160 to form a pull tab.
[0066] Where the book cover spine and/or media for insertion is long, or wide, multiple release strips can be used to expose only a portion of the adhesive strip at a time. For example, as shown in FIG. 5 b , two release strips 160 can be placed on a single adhesive strip 145 , wherein the release strips 160 each are V-folded, and the V-folded portions of each release strip 160 abut, resulting in a pullable release strip section on either end of the adhesive strip 145 . Removing shorter lengths of release strip can make it easier for a user to hold the media in place with respect to the adhesive strip, or the adhesive strip in place with respect to the book cover spine, with one hand, and remove the release strip with the other hand. Book covers with multiple attached adhesive and release strips are exemplified in FIGS. 6 a - c. FIGS. 6 a and 6 b are plan and side views, respectively, of a book cover 100 having spine section 65 bounded by spine creases 60 . As shown in plan view FIG. 6 a , two adhesive strips with attached release strips 170 are located side-by side between the spine creases 60 . As shown in corresponding side view FIG. 6 b , the two adhesive strips 145 with attached release strips 160 (collectively indicated in 5 a as 170 ), are situated in the spine section 65 bounded by spine creases 60 . FIG. 6 c is plan view of a book cover 100 having two adhesive strips with attached release strips 170 laid end-to-end along the length of the spine section bounded by the spine creases 60 .
[0067] Once removed, the one or more release strip can be retained, for example, as a bookmark. The release strip can be printed, embossed, or otherwise marked with indicia, for example, text, graphics, or figures, indicating how to remove the release strip from the adhesive strip. The release strip can be printed, embossed, or otherwise marked with indicia, for example, for special occasions, for example, a birthday, anniversary, graduation, or holiday, people's names, images, decorative scenes, or graphic designs. The release strip can be one or more colors. The release strip can be a different color than the adhesive strip for easy identification of the adhesive strip versus the release strip.
[0068] The book cover and adhesive strip can be provided as a system or kit for use in binding media into book form. The book cover can be provided with a single width spine section and pre-adhered adhesive strip having one or more release strip for insertion of the media.
[0069] The book cover can have indicia for multiple spine creases. Where a choice of spine section width is so provided, the book cover can include a single, pre-attached adhesive strip with a release layer. Alternately, the book cover with selectable spine section width can have multiple, pre-attached adhesive strips each having at least one of its own release layer so that only the needed adhesive strip(s) can be exposed to match the selected spine section width. In such a configuration, there may be a main, wider adhesive strip, and additional narrow adhesive strips adjacent the main adhesive strip, wherein each narrow adhesive strip corresponds to an additional spine section width.
[0070] The book cover can be chosen from a selection. If the adhesive is provided separately, it can also be chosen to match the width of the selected book cover spine section, to provide indicia as desired on the release strip, or a combination thereof.
[0071] A system or kit can include a single book cover and multiple adhesive strips of varying dimensions so the user can select the appropriately dimensioned adhesive strip for the spine section width as determined by the media to be inserted. Alternately, a system or kit can be provided with multiple book covers, and multiple adhesive strips, wherein more adhesive strips than book covers are provided, again to allow the user proper matching of the book cover spine section width and adhesive strip to the media bundle to be inserted.
[0072] Where adhesive strips are provided separately, they can have a release strip on at least two sides, a first side to face the book cover spine section, and a second side to face the media for insertion. The release strips can be the same or different in appearance. For example, the release strip to face the media insertion side could be decorative, while the release strip for the book cover spine section side is plain in appearance. If an adhesive strip is particularly thick, side release strips may also be provided if the sides of the adhesive strip are tacky. The sides can be adhered to a portion of the spine section, but preferentially do not interfere with the spine crease so that flexibility of the book cover is maintained. This can be accomplished, for example, where the book cover spine section is a channel, the upper edges of the channel forming the flexible crease that allow movement of the front and back portions of the book cover.
[0073] The system or kit can include decorative items for addition to the book cover or media as desired. For example, the system or kit can include stickers of images, text, or graphics, decorative writing materials for use on the book cover or media, sparkles, stars, or other materials. The system or kit can also include blank or pre-decorated media, attachable page tabs, separator pages with or without tabs, or other media forms.
[0074] The system or kit can include a coating powder for covering the adhesive strip once the media is inserted. Once the release strip is removed, and the adhesive strip is adhered to the book cover spine section and the media is inserted in the adhesive strip, portions of the adhesive strip may remain exposed. Due to the tackiness of the adhesive strip, it may be desirable to coat the exposed areas of the adhesive strip with a substance to eliminate the remaining tacky or sticky surfaces wherever possible. Any suitable inert coating material can be used, for example, but not limited to, chalk, talcum powder, silica beads, glass beads, colored dust particles, paper fiber, glitter, or sparkles. The coating material can be supplied in a solid form, such as a pencil, chalk, or solid stick. The coating material can be supplied as a powder in a dispenser, for example, in a sealed container such as an envelope, box, or canister. The coating material can be supplied in an aerolized or aerolizable form, for example but not limited to a squeeze bulb, pump bottle, or aerosol. The coating material can be any color. For example, the coating material can be transparent, the same color as the adhesive strip, the same color as the media, the same color as the book cover, or any decorative color or colors desirable, including metallic. A choice of coating materials could be provided when the book cover system or kit is purchased by a user, or a selection of coating materials can be provided in the system or kit at the time of purchase.
[0075] The system or kit can include one or more media clamp, The function of a media clamp is to aid the user in pinching the media together to form a tight media stack or bundle for insertion into the adhesive strip in the book cover spine section. The media clamp can be any item suitable for this purpose. For example, one or more a paper clip, binder clip, alligator clip, or other vise-like or clamp-like device can be provided or used to force the media into a tighter bundle. Two separate pieces may also form a media clamp, wherein one piece is held on each side of the media, and the user exerts force on the two pieces towards one another (squeezes) to force the media together. Preferably, a media clamp, whether of one or two pieces, has a sufficient width to distribute its force over an area of the media. Use of the media clamp near the edges of the media for insertion in the adhesive strip can also result in the media edges flaring slightly, separating each medium from the adjacent medium and allowing maximum insertion of each medium in the bundle or stack into the adhesive strip. The use of the media clamp also imparts further rigidity to the insertion media bundle, allowing for deeper penetration into the adhesive strip.
[0076] The media clamp, if in two or more pieces, can be formed as part of the book cover. For example, a raised section can be formed on the inside of the front and back inside portions of the book cover near the spine section. These media clamps could be removable after use. For example, they could be affixed to the book cover by Velcro or removable adhesive, or clipped or clamped over the book cover edges, for removal once the media has been inserted into the adhesive strip. Alternately, the book cover itself can function as a media clamp if the media bundle for insertion is sufficiently thick, or the book cover is formed with appropriate internal raised sections, ridges, or curvatures.
[0077] The media for use with the book cover and adhesive strip described herein can be any media that has sufficient stiffness to penetrate the adhesive. The required stiffness can result from being held in a bundle by the user or a media clamp. Deep penetration of the adhesive strip is not required. Penetration sufficient to allow the adhesive strip to bind to a portion of the front and back surface of a medium, as well as the edge, is desired for maximum hold. The penetration should be sufficient so each inserted medium does not come separate from the adhesive strip in normal use (turning of media pages in the book cover). The penetration should be sufficient so individual medium can have force exerted along the medium in a direction away from and perpendicular to the adhesive strip, and the medium will extend with the adhesive strip, but not separate therefrom, at least to the point the adhesive strip reaches a maximum elongation at break. The elongation at break can be, for example, about 300% the thickness of the adhesive strip at room temperature. Adhesives with shorter or longer elongation at break maximums are possible and can be used. Longer maximums can allow for excessive stretching of the media from the book cover, which can result in damage to the media. Shorter maximums may not allow enough give for normal usage. However, the elongation at break is merely one of several properties of an adhesive to consider, the other properties being discussed elsewhere herein.
[0078] Media suitable for insertion can include, but are not limited to, natural and synthetic papers; synthetic sheets such but not limited to as plastic, mylar, or vinyl; cardboard and other paper or pulp materials; stiff fabrics; reinforced fabrics; mixed media sheets; photographs; metal sheets; glass plates; and other sheet-like materials. Any medium that has sufficient stiffness to penetrate the adhesive, is not too heavy for the adhesive to retain, and is of desirable dimensions and stiffness to please the user is acceptable. The medium must be light enough to not exceed the adhesive or cohesive strength of the adhesive strip. This can be tested by insertion of the desired number of such media into an adhesive strip attached to a book cover, and determining if the media can be easily removed by an upward pull (the orientation a user would normally have relative to the adhesive strip) away from the book cover, or if holding the book cover so the adhesive strip and media face downward allows the media to work free of the adhesive strip or separates the adhesive strip from the book cover.
[0079] Media inserted into a book cover can be all the same medium, or different mediums. Each medium independently can be decorative, plain, mixed media, or have attachments thereto. Commercially available media such as photobook pages, templates, and framing pages (for example, of paper, paperboard, cardboard), can be used. A medium can have a V-fold shape, such that the edge for insertion is the V-folded edge, the free edges forming the edges of the pages for turning in the book cover. Pop-up pages, and pages with extension section that open out from the book cover can also be used.
[0080] To maximize adhesion of the media to the adhesive strip, the edge of a medium for insertion can be uneven. For example, the edge for insertion can be roughened, frayed, perforated, regularly or irregularly cut, or otherwise made to have an increased surface area to promote adhesion. Rough edges provide more surface area, and can allow more wicking of the adhesive strip material around each medium, for maximum adhesion. A V-folded page set 260 of perforated media is shown in FIGS. 7 a and 7 b. The V-folded page set 260 has a center crease 270 with perforations 280 . The V-folded page set 260 can be inserted into an adhesive strip 145 in the spine section 65 of a cover such that an adhesive protrusion 290 forms between the media portions of the perforations 275 of the perforated V-folded page set 260 , as shown in FIG. 8 . The adhesive protrusions 290 increase the adhesive bond between the adhesive strip 145 and the V-folded page set 260 by increasing the surface area of the V-folded page set 260 in contact with the adhesive strip 145 .
[0081] The media could be provided with the book cover system or kit in a size and amount appropriate to fill the accompanying binder. The prepared media stack provided with the book cover could be selected from media appropriate with commonly found home printers, for example, but not limited to, ink jet media, laser printer media, dot matrix media, and thermal receiver media, possibly including a thermal donor media kit appropriately sized to the receiver media stack as well. Kits for use by commercial stores, such as, for example, craft stores, pharmacies, printers, copiers, and general retail stores with imaging departments, where the store can fulfill a text, photographic, or combination print order, can include the above typical media types, or media appropriate for electrophotographic printers, high speed ink jet printers, lithographic printers, photographic printers, or any other printer type. The prepared media stack could also be provided or sold with an indicator of the appropriate book cover(s) for which it can be used. Such an indicator could include a serial or stock number of the book cover; book cover dimensions including height, width, and thickness; book cover reference style names; or any other known corresponding coding method. This allows a user or commercial establishment to choose the appropriate media type for the printer to be used. Further, the prepared media kit could be sold with the appropriate sized toner, donor media, ink, paint, or other marking material sufficient to print all the sheets in the media bundle with the desired printing method.
[0082] It is noted that roll fed media can be used, but must be cut prior to insertion into the book cover, or folded such that the edges can be cut to form pages after insertion in the book cover. Perforated roll media can be used in alternate folds without precutting because the adhesive strip will wick through the perforations onto either side of the media. If the adhesive strip is sufficiently tacky or sticky, one or more prestitched, prestapled, or otherwise preformed V- or nested-stack of media could be inserted into the adhesive strip in the book cover.
[0083] To use the material described herein, a user will first purchase a system or kit, or select the independent material of a book cover and adhesive strip. The selection of the book cover should be made with the maximum spine section width in mind, which spine section width should be wider than the media stack intended to be inserted into the book cover. It is desirable that the spine width be at least slightly wider than the media stack, but the widths can be identical, or the media stack can be significantly narrower than the spine width if desired.
[0084] If the book cover has multiple possible spine widths, a user can select the appropriate spine width and then flex the book cover to create the spine creases in the correct positions to define the appropriate spine width.
[0085] If the adhesive strip(s) is not pre-adhered to the spine section of the book cover, a user can position the adhesive strip(s) within the spine section as needed, and remove the release strip between the adhesive strip(s) and the book cover spine section while holding the adhesive strip(s) in position. The adhesive strip(s) can then be firmly pressed against the spine section of the book cover to ensure adhesion. The adhesive strip(s) on the spine section can be pressed with or into a surface, for example, using a finger, a ruler, book, block of wood, along a table or table edge, to ensure adhesion to the spine section for the full width and length of the adhesive strip.
[0086] Once a book cover with an attached adhesive strip(s) is in hand, a user will collect the desired media to form the media bundle for insertion. The media should be stacked, with at least one edge of all media aligned. If two or more V-fold shaped media are used, the V-fold edges are aligned in the stack. The V-fold shaped media are not stacked or nested within each other, but can be adjacent one another in a stack, or separated by non-V-fold shaped media. Each medium must independently be in contact with the adhesive strip.
[0087] Once the media is stacked, a media clamp optionally can be applied to compress the media into a tighter bundle. Use of the media clamp on the bottom third of the media towards the aligned edges, but not at the aligned edges, can cause the aligned edges to flare, separating them from each other and allowing better adhesion of each medium to the adhesive strip. The media clamp can be formed as part of the book cover, as shown, for example, in FIGS. 9 a and 9 b . FIGS. 9 a and 9 b are a plan view and side view, respectively, of a book cover 100 having an adhesive strip 145 with attached release strip 160 , collectively 170 , between spine creases 60 , and media clamps 180 on either side of the spine section.
[0088] As shown in FIGS. 10 a and 10 b , the aligned edge of the media bundle 150 is positioned on the adhesive strip 145 with attached release strip 160 (collectively 170 ), with application of a firm downward force. The media bundle 150 can be horizontally and vertically centered on the adhesive strip 145 for a symmetrical appearance, however alternate placement is possible as desired by a user. As shown in FIG. 11 a land close-up FIG. 11 b, the media bundle 150 , with or without use of a media clamp 180 , should be slightly compressed above the aligned edges for insertion. Preferably, the release strip facing the media bundle is removed after the media bundle is positioned and held into place against the release strip on the adhesive strip. The release strip could be removed before positioning of the media bundle, however once a medium has adhered to the adhesive strip, it will not be repositionable, so greater care is necessary if the release strip is removed before positioning the media bundle. As the release strip is removed, the media bundle will embed into the adhesive strip. If a media clamp was used, it is now removed from the media bundle.
[0089] If the media clamp is part of the book cover, or removably attached thereto, the media is aligned, positioned against the release strip on the adhesive strip, and the book cover is closed against the media, as shown in FIGS. 10 a - b and 11 , holding the media bundle 150 in place and compressing the media at least where the media clamps 180 are positioned within the book cover 100 . As shown in the call-out of FIG. 11 , the media clamps 180 compress the media bundle 150 such that the ends of the media within the bundle fan outwards, creating space between each medium in the bundle as they are located on top of the release strip 160 . As shown in FIG. 12 , the release strip 160 is then removed, allowing contact between the media bundle 150 and the adhesive strip 145 . As shown in FIG. 12 , because the media clamps 180 are still in place, the media bundle 150 still appears flared within the adhesive strip 145 . FIGS. 13 a - c show a side view of the removal of release strip 160 from adhesive strip 145 . FIG. 13 a shows the release strip 160 adheres to the adhesive strip 145 as a unit 170 , with media bundle 150 pressed against the release strip 160 . FIG. 13 b shows the release strip 160 partially removed from the adhesive strip 145 . FIG. 13 c shows the release strip 160 completely removed from the adhesive strip 145 , such that media bundle 150 is directly in contact with adhesive strip 145 . It is noted the book cover itself can function as a media clamp, particularly where a media bundle is nearly equivalent in width to the spine section of the book cover. Once the media bundle 150 is in contact with the adhesive strip 145 , the media clamps 180 optionally can be removed, allowing the media within the media bundle 150 to return to an uncompressed state, resulting in a finished book 210 , as shown in FIG. 14 and the call-out therein.
[0090] Optionally, once the media bundle is embedded in the adhesive strip, a coating material 310 can be applied to the adhesive strip 145 to cover all remaining surfaces, such that no tacky or sticky surfaces of the adhesive strip remain, as shown in FIG. 15 , wherein the coating-covered adhesive 320 has little or no tackiness to the surface. The coating material can be applied by any means, for example but not limited to, rubbing, sprinkling, pouring, brushing, or blowing the coating material onto the adhesive strip. As shown in FIG. 15 , the coating material 310 can be supplied in a packet 300 , a container, pre-coated on a brush or swab, or in any other suitable format. The edges of the adhesive strip beyond the media bundle can be coated. If desired, the pages in the media bundle can be separated and coating material applied between the pages at the adhesive strip as well. Excess coating material can be removed by any suitable method, for example but limited to, wiping, blowing, brushing, or shaking excess coating material from the adhesive strip, pages of the media bundle, book cover, or some combination thereof.
[0091] The assembled book can now be used. Any V-fold shaped medium 260 in the book 210 can be seen to create an uninterrupted single page 230 when the edges of the V-fold shaped medium are separated, as shown in FIG. 16 . Because there is no stitching, binding, staples, rings, or other penetrating media, and because the media are not clamped into a binding, the V-fold shaped media pages 260 , or any two adjacent pages, can be opened to at least 150 degrees from the adjacent media (or other half of the V-folded page), allowing each page to be viewed edge-to-edge. This is ideal for insertion of panoramic images, or decorative sheets or prints that span both sides of a V-fold medium. As can be seen in FIG. 16 , the adhesive strip deforms 250 to accommodate the angle of opened pages without letting go of the pages. This deformation is assisted by the adhesive protrusions 290 that occur between the media, holding each medium in place while the adhesive strip flexes to accommodate movement of the medium.
[0092] The assembled book does not require page trimming because the pages are not nested. If all media in the bundle is of the same dimensions and aligned before insertion into the book cover, the resulting book pages will be similarly aligned in all dimensions. Intentional use of media of different dimensions is envisioned as well, and will result in uneven edges on at least one side of the media pages, per the user's intent.
[0093] The book cover, adhesive strip, or both can be any shape suitable for use. In most cases, the book cover and adhesive strip are both expected to be rectilinear in shape. However, both geometric and asymmetric shapes are envisioned for use as appropriate to the user's intentions for both the book cover and insertion media. For example, an art book may require non-rectilinear shapes of the book cover to achieve the desired artistic effect, for example, where the finished book is meant to open in appearance like a rounded clam shell, or opening flower petals, where the media is at the core. Such shapes of the book cover and insertion media may require asymmetrical or geometrically shaped adhesive strips. Thus, the term “strip” as used in conjunction with “adhesive” or “release” herein is meant to convey a material size that is capable of handling and manipulation by a user, not a particular shape.
[0094] The invention has been described with reference to various specific embodiments. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
PARTS LIST
[0000]
10 Assembled “Prior Art” Adhesive Photo Print Binding System
20 Photo Print Binder Cover
30 Flexible Substrate
40 Close-up View of Spine Section
50 Flexible Substrate Underside Adhesive Strip
60 Flexible Spine Crease
62 Spine Crease Indicator(s)
65 Spine Section
70 Photo Prints
80 Pressure Sensitive Adhesive
90 Floating Spine Section
100 Book Cover
110 Gel Adhesive
120 Gel Adhesive Containment Tray
130 Adhesive Impregnated Foam Strip
140 Cast Gel Adhesive Strip
150 Media Bundle
160 Release Strip
170 Adhesive Strip with Attached Release Strip
180 Disposable Media Clamp
210 Finished Book
230 Uninterrupted Page View
250 Adhesive Strip Deformed
260 V-Folded Page Set
270 Center Crease
275 Media Portion of Perforated Media
280 Perforations
290 Adhesive Protrusion
300 Coating Material Packet
310 Free Falling Coating Material
320 Adhesive Strip with Coating Materal
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An instant book binding system and book cover for rapidly binding single- or double-sided documents, photographs, pages, and other forms of hardcopy media into soft or hard cover books is disclosed. The book binding method using the book cover or system can be performed without special skills or training, and does not require the use of ancillary equipment. The book cover system can be used in conjunction with output on a wide variety of media types, finishes, and stock weights from any type of printer or copier, or with photographs. The finished books retain the appearance and function of conventional mass produced soft and hard covered books.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method and a furnace for the vapor phase deposition of components onto semiconductor substrates.
[0003] As the computer power and the storage capacity of microchips have been continually increasing, the integration density of the electronic components, such as transistors or capacitors, has continually increased. What is referred to as Moore's law, which describes a doubling of the integration density in a period of 18 months, has thus held true for more than 30 years. In the future, the industry will attempt to increase the performance of microchips and also special components such, as e.g. video chips, in the context of Moore's law so that the electronic components must be miniaturized further.
[0004] A higher degree of integration is essentially achieved by further reducing the size of the functional elements. This concurrently leads to an increase in the operating speed of the microchip. In parallel with a rising integration density, there is also an increase in the average wafer diameter and thus in the demands on the homogeneity of the wafer surface or the layers deposited thereon. Therefore, the realization of submicron structures is at the present time one of the most important tasks for the further development of microelectronics. This gives rise to more stringent requirements made of the entire technology for fabricating microelectronic components. The individual technological steps must in part be utilized right up to their fundamental limits and new methods must be developed and introduced into industrial production.
[0005] One typical production step in the fabrication of microchips is the deposition of a layer made of a specific layer material on a wafer. The layer may be modified, if appropriate, in terms of its chemical and/or physical properties in a further production step. The deposited and, if appropriate, modified layer may subsequently be patterned by selectively removing specific sections of the layer. The layer may be produced by oxidizing or nitriding the wafer in a suitable atmosphere, for example, in order to obtain a layer made of silicon oxide or silicon nitride. Layers of these and other materials are preferably produced by methods utilizing relatively low temperatures. One example of such a method is chemical deposition from the vapor phase (chemical vapor deposition, CVD), which is usually carried out at temperatures of a few hundred degrees Celsius and within a wide pressure spectrum. In CVD methods, a substrate in a CVD process space is exposed to a flow including one or more gaseous components. The process gases are, by way of example, gaseous chemical precursor compounds of the layer material or inert carrier gases which transport the precursor compounds in solid and liquid form. The layer material is produced from the precursor compounds photolytically, thermally and/or in plasma-enhanced fashion in the CVD process space and/or above the substrate surface. The layer material is deposited on the substrate surface and forms a layer.
[0006] A high integration density as demanded particularly in the case of electronic components, such as processors and semiconductor memory devices, presupposes very small layer thicknesses and small dimensions for structures in the layer. Layer thicknesses of a few nanometers and structure dimensions of a few tens of nanometers have become customary in the meantime.
[0007] The continual miniaturization increases the demands on the layer quality determined by the defect density, roughness and homogeneity of the layer. In this case, the roughness describes a deviation of a surface of a layer from an ideally planar surface. The defect density is a measure of the number and the size of impurities or structural defects in the layer.
[0008] In this case, impurities are inclusions made of a different material than the layer material.
[0009] Structural defects may be, by way of example, voids or, in the case of crystallizing layer materials, lattice defects. Homogeneity relates to the physical and chemical uniformity of the layer. Customary methods for fabricating layers having a layer thickness of less than 1 μm on a substrate are epitaxial methods, physical vapor phase deposition (physical vapor deposition, PVD methods) and chemical vapor phase deposition (chemical vapor deposition, CVD methods).
[0010] The layers are deposited in single-wafer installations or in multiwafer installations. In multiwafer installations, a plurality of wafers are stacked one above the other at a short distance in a suitable rack. The rack, referred to as a “boat”, charged with a plurality of wafers is then introduced into the process space of a furnace. The process gas containing the components to be deposited is introduced for example at the underside of the process space and then rises laterally past the wafers stacked one above the other and upward along this flow direction. This flow direction along which the principal convection material transport takes place is referred to as the main flow direction. The process gas is discharged at the top side of the process space. For this purpose, the process gas may either be passed out through a discharge line at the upper side of the furnace or it may be deflected and passed downward on the outside of the process space in order then to be pumped away at the underside of the furnace. The components contained in the process gas diffuse out of the main flow flowing laterally upward past the wafer stack into the interspace between two wafers arranged one above the other in order then to reach the wafer surface and subsequently be deposited there. The mass transfer is principally effected by diffusion, but other phenomena such as convection and thermodiffusion (Soret effect) are involved. In this case, the diffusion flow of the components out of the main flow into the space between the wafers is determined by the concentration gradient of the components in the main flow of the process gas. While the process gas rises from the bottom upward, it is thus continuously depleted of components. The consequential products thereof are deposited on the surface of the wafers, with the result that a concentration gradient is established along the main flow direction. Since the quantity of the component that is transported out of the main gas flow between the wafers depends on the set concentration gradient of the component in the main gas flow, it is possible for a larger quantity of the component to pass into the interspace between two wafers arranged one above the other in the lower region of the process space, in which the main gas flow still has a high concentration of the component, than in the upper region of the process space in which the main gas flow is largely depleted of the component. The consequence of this is that the thickness of the deposited layer is larger on wafers arranged in the lower region of the process space than in the case of wafers arranged in the upper region of the process space. Such inhomogeneities are not infrequent during nitride deposition. An analogous effect is observed when doping the silicon wafers. A high doping is effected in the lower region of the process space into which fresh dopant is continually fed, while a significantly lower doping is effected in the upper regions.
[0011] The inhomogeneities produced in this way within the process space lead to a nonuniform distribution of the material parameters of the treated semiconductor substrates within a batch and, associated with this, to different electronic properties of the same component on different wafers of a batch. However, in microelectronics, in particular, extremely stringent requirements are made of the stability and the reproducibility of the fabrication steps of the electronic components.
[0012] Therefore, efforts have been made to combat the different rates of deposition of the components on wafers of a batch.
[0013] Thus, it has been proposed to provide injectors in the process space along the main flow direction. These injectors would enable dopants or other components, which are to be deposited on the wafer, to be fed into the process space. In this way, it is possible to replace the quantity of the component that has been removed from the process gas and deposited on the wafer. This means that a depletion of the component in the process gas is counteracted and the change of the concentration gradient in the process gas along the main flow direction can be suppressed. However, this solution is technically very complicated since, on the one hand, it is necessary to incorporate injectors into the process space and, on the other hand, the quantity of component fed to the process space by the injectors has to be regulated such that only the consumed quantity of the component is replaced in each case. However, injectors are highly susceptible to functional failures, such as those that occur for example, due to mechanical fracture defects.
[0014] A further possibility that is afforded is to use smaller batch sizes in order to minimize differences between the first and last wafers of a batch. However, the lower turnover per fabrication cycle means that it is necessary to expend a higher outlay with regard to costs, as a result of which the economy of the method decreases.
[0015] Furthermore, in order to balance the layer thicknesses obtained, it is possible to provide a temperature gradient within the process space. The deposition rate which is increased at a higher temperature makes it possible to counteract the depletion of the component to be deposited in the main gas flow. Temperature differences of several degrees are not infrequent, as during nitride deposition, in particular. With this method, although it is possible to achieve uniform layer thicknesses within a batch, the wafers of a batch nonetheless experience a different thermal budget. As a result, in later process steps, differences may occur in the processing of the wafers or, in the finished product, differences may occur in the electronic parameters between chips from different wafers.
[0016] In single-wafer installations, nonuniformities of temperature and concentration profiles can be compensated for by rotating the wafer about its axis. This method is offered by most manufacturers nowadays. This method is unfavorable for multiwafer installations since a rotation of the wafers or of the boat can be realized technically only with difficulty and, in multiwafer installations, the main flow direction of the process gas generally runs parallel to the normal to the wafer area and not parallel to the wafer surface, which is the case in single-wafer installations. Therefore, a concentration gradient along the main flow direction cannot be compensated for by rotating the boat about its longitudinal axis. This means that the boat rotation essentially only has a positive effect on the uniformity within a wafer, but the homogeneity of the individual wafers among one another is barely influenced.
[0017] In this case, the aspect of the uniformity of the wafers among one another becomes all the more critical, the smaller the feature sizes become. If the critical feature size is to be reduced further, the regularity with which layers are deposited within a batch must be increased further.
SUMMARY OF THE INVENTION
[0018] It is accordingly an object of the invention to provide a furnace and a method for vapor phase depositing components on a semiconductor substrate, which overcome the above-mentioned disadvantages of the prior art apparatus and methods of this general type.
[0019] In particular, it is an object of the invention to provide a method for vapor phase depositing components on a semiconductor substrate in which, even in the case of relatively large batch sizes, only slight fluctuations in the layer properties between two wafers are observed or in which fluctuations in the layer thickness of a layer deposited on a semiconductor substrate can be reduced.
[0020] With the foregoing and other objects in view there is provided, in accordance with the invention, a method for vapor phase deposition. The method includes: vapor phase depositing components contained in a process gas flowing along a main flow direction onto at least one semiconductor substrate situated in a process space; and during the step of vapor phase depositing, changing the main flow direction at least once.
[0021] In the method, the semiconductor substrates are first arranged in a customary manner in the process space. If a plurality of semiconductor substrates are situated in the process space, they are generally arranged (stacked) one above the other at a short distance. The process gases containing the components that are to be deposited on the semiconductor substrate are subsequently introduced into the process space. For this purpose, the process space includes at least one feed line that can be opened or closed off e.g. by a supply valve and through which the process gas is supplied to the process space, and also at least one discharge line through which the process gas is passed out of the process space by being pumped away, for example. A main flow direction along which the process gas flows through the process space is established between the feed line and the corresponding discharge line. As described above, a first concentration gradient is established in the process space for the components supplied. The concentration gradient leads to fluctuations in the layer thickness between individual semiconductor substrates of a batch or, in single-wafer installations, on the surface of the semiconductor substrate. If the main flow direction is then changed, a second concentration gradient is established, which differs from the first concentration gradient. The fluctuations that are observed within a batch between individual semiconductor substrates or, in single-wafer installations, on the surface of the wafer also change as a consequence. The changeover of the main flow direction is effected, if possible, such that the fluctuations in the properties of the deposited layer which are established between the individual semiconductor substrates of a batch in a multiwafer installation or on the surface of the semiconductor substrate in a single-wafer installation are largely compensated for.
[0022] Thus, by changing the main flow direction once or a number of times, it is possible to compensate for concentration gradients that are established for the components in the process space. As a result, it is also possible to avoid different layer thicknesses on semiconductor substrates of a batch, so that it is possible to achieve a significantly more uniform quality of the processed semiconductor substrates.
[0023] The method improves the uniformity of the treated semiconductor substrates, for example, with regard to the thickness of the deposited layer or a doping. It is not necessary to provide a temperature gradient in the process space. The temperature can be kept constant or can be varied uniformly in the entire process space. The semiconductor substrates of a batch therefore all experience the same thermal budget, i.e. they are heated to the same temperature for the same period of time. As a result, the reproducibility of the electronic properties of the microelectronic components produced is increased and the yield of functional circuits is increased.
[0024] An essential advantage of the method is the possibility of increasing the batch size further. The variable main flow direction significantly reduces the problem which concerns local concentration depletion and occurs particularly with relatively larger batch sizes. It is thus possible to use significantly larger batch sizes and thus to fabricate more components than hitherto within a production cycle. The economy of the method is significantly improved as a result.
[0025] The method is inherently independent of the size of the processed semiconductor substrates. Thus, wafers having a relatively large diameter, e.g. having a size of 300 mm or more, can also be processed without any problems. It goes without saying, however, that the method can also be used for processing smaller wafers.
[0026] Since concentration gradients in the process space are largely compensated for in the course of the method, it is sufficient if dopants for controlling the electronic properties of the semiconductor substrates are introduced into the process space as a process gas at only one location. Therefore, it is not necessary to provide lateral injection nozzles (injectors) along the main flow direction in the process space in order to compensate for a depletion of dopant in the process gas. The apparatuses suitable for carrying out the method can therefore be embodied in a structurally simple manner and are therefore insensitive to technical disturbances.
[0027] Of course, installations equipped with injectors may likewise be operated using the method, and use of the injectors can provide for an additional increase in the homogeneity.
[0028] The method thus improves the uniformity within a wafer batch. This relates both to the layer thickness and to the doping and the thermal budget. As a result, the reproducibility of the electronic properties of the electronic components fabricated from the semiconductor substrates is improved and, consequently, the yield of the circuits thereby fabricated is increased. This results in an increased yield of functional components and an associated increase in the productivity of the method.
[0029] In a preferred embodiment of the method, the main flow direction is reversed. A reversal of the main flow direction corresponds to a maximum change in the main flow direction. A maximum change in the flows within the furnace and thus an extensive compensation of concentration and temperature gradients take place in this case. As already described above, in multilayer installations, the semiconductor substrates are arranged in the process space in a manner stacked one above another at a short distance, and the process gas flows laterally past the stack forming a main flow direction. For this purpose, the process gas may be introduced into the process space e.g. at the underside. After a specific period of time, the main flow direction is reversed, i.e. the process gas is then introduced at the top side—opposite to the underside—of the process space. The main flow direction therefore changes by 180°. In single-wafer installations, the process gas flows parallel to the wafer surface. In this case, too, the main flow direction is reversed, that is to say rotated through 180°, after a specific period of time in order to compensate for concentration and temperature gradients. In single-wafer installations, it may be advantageous to change the main flow direction in smaller steps, e.g. by 90° in each case, in order to achieve an optimum compensation of the temperature and concentration gradients.
[0030] Therefore, it is advantageous if the main flow direction is oriented parallel to an axis of symmetry of the semiconductor substrates. In the event of a change in the main flow direction, concentration gradients are compensated for in a symmetrical manner along the axis of symmetry of the substrates. The homogeneity of the coated semiconductor substrates can then be significantly improved.
[0031] The axis of symmetry is preferably a rotation axis or a rotary mirror axis. These axes of symmetry have a particularly high degree of symmetry in comparison with other axes of symmetry, so that a particularly effective compensation of the concentration gradients is achieved when the main flow direction is oriented parallel to such an axis of symmetry. In multiwafer installations, the rotation axis runs perpendicular to the surface of the semiconductor substrate in the center of the stack. Therefore, as already described, the process gas flows laterally past the semiconductor stack along the main flow direction. In single-wafer installations, the rotary mirror axis runs along the wafer surface through the midpoint of the surface of the semiconductor substrate. The process gas therefore flows parallel to the wafer surface along the main flow direction across the semiconductor substrate.
[0032] In a preferred embodiment of the method, the process gas is at least partially removed from the process space before changing the main flow direction. The process gas introduced into the process space directly before changing the main flow direction no longer traverses the entire path through the process space, but rather experiences a flow reversal. If one takes a specific volume of the process gas flow which was introduced into the process space shortly before the flow reversal, the volume, up to the flow reversal, passes only as far as one of the lower semiconductor substrates of the stack in order then to be discharged from the process space in the opposite direction. The semiconductor substrates at the outer ends of the stack therefore experience an additionally intensified layer thickness growth. The effect may become apparent particularly when the main flow direction is changed repeatedly. Through skilful implementation of the method, this effect can be utilized to compensate for a reduced layer thickness growth at the ends of the wafer stack, caused by the low concentration of the components in the process gas, before this leaves the process space during the customary deposition. In order to avoid additional inhomogeneities, however, it is more favorable for process gas that is still present in the process space to be removed before the change in the main flow direction. As a result, fresh process gas can be introduced into the process space, which then flows through the process space over its entire extent. The desired concentration or temperature gradient then forms directly.
[0033] The removal of the process gas from the process space may be effected by reducing the supply of process gas into the process space and/or by extracting process gas from the process space and/or by flushing the process space with an inert gas (e.g. noble gas or nitrogen). In the case of the embodiment mentioned last, pressure surges in the reaction chamber are avoided.
[0034] The composition of the process gas supplied usually remains unchanged during the deposition of a layer or the introduction of a doping. It may be advantageous for specific requirements, however, if the components have a different composition and/or concentration after the change in the main flow direction. The flexibility of the method is thereby increased and it is possible, for example by using different dopant concentrations, to produce specific doping profiles in the semiconductor substrates and thereby to adapt electronic properties in a targeted manner.
[0035] Furthermore, by changing the composition of the process gas, it is possible, by way of example, also to realize layers including a plurality of different layers or particular defect structures, e.g. by changing the dopant.
[0036] According to one embodiment of the method, layers are fabricated, and the components contained in the process gas react chemically with the material of the semiconductor substrates. A chemical reaction between the components to be deposited and the semiconductor substrates liberates significantly higher quantities of energy than physical adsorption. The stability thereby achieved in the deposition layer produced is accordingly significantly higher, as a result of which service life and resistance to external influences such as mechanical and thermal loads or behavior toward moisture and chemicals can be optimized. Examples of such layers are layers made of silicon dioxide or silicon nitride. However, the method is also suitable for the fabrication of layers in which the components contained in the process gas all form the starting materials for the layer. In this case, the component may be deposited directly as the material of the layer (PVD; “Physical Vapor Deposition”) or the material of the layer may be formed in a chemical reaction (CVD; “Chemical Vapor Deposition”).
[0037] The vapor phase deposition can take place at atmospheric pressure, subatmospheric pressure, and in the near-vacuum range, subatmospheric pressure is preferred.
[0038] In a preferred embodiment of the method, the change in the main flow direction is effected in accordance with a variable time pattern. As a result, by way of example, it is possible to change the main flow direction with a higher frequency at the beginning of the vapor phase deposition in order first to obtain a starter layer that is as uniform as possible on all the semiconductor substrates. In a later stage of the method, when a constant deposition rate has been established for the individual semiconductor substrates, a lower frequency of the change in the main flow direction with longer interval ranges may then also be sufficient. In the case of depositions wherein the deposition rate remains essentially constant during the entire deposition, one change of direction is enough.
[0039] In a further embodiment of the method, an online detection of the quantity and/or the distribution of the components deposited onto the semiconductor substrates is effected during the method. As a result, the instantaneous deposition results with regard to the layer thickness and the quality are obtained directly. In the event of disturbances occurring or incomplete deposition, corresponding measures and corrections can be initiated immediately, so that it is possible to fabricate layers with high quality reproducibly.
[0040] An essential feature of the method is the change in the main flow direction in the process space. Therefore, specially configured furnaces are required to carry out the method. Therefore, the invention also relates to a furnace for the vapor phase deposition of components contained in a process gas onto one or more semiconductor substrates.
[0041] With the foregoing and other objects in view there is provided, in accordance with the invention, a furnace for vapor phase depositing components contained in a process gas onto at least one semiconductor substrate. The furnace includes: a process space for receiving the semiconductor substrate; a first feed/discharge line connected to the process space; a second feed/discharge line connected to the process space; a device for producing a process gas flow, the device for producing the process gas flow connected to the first feed/discharge line and/or the second feed/discharge line; a heating device; and a regulating unit for regulating a magnitude and a flow direction of the process gas flow.
[0042] This furnace makes it possible to achieve a homogeneous deposition of components on semiconductor substrates, so that a uniform coating of the semiconductor substrates with regard to layer thickness and layer quality is obtained even with extensive batch sizes. The furnace may be configured both as a single-wafer installation and as a multiwafer installation.
[0043] Since the electronic properties depend significantly on the material properties, the electronic quality of the microelectronic circuits produced from these semiconductor substrates is significantly improved. Therefore, the furnace makes it possible to fabricate microelectronic components with reduced dimensions.
[0044] The furnace differs from the furnaces used hitherto essentially by virtue of providing an apparatus that can vary or reverse the flow in the process space of the furnace. As already explained in connection with the method, a process gas containing the components to be deposited flows through the process space. The process gas is depleted because of the deposition of the components, so that a concentration gradient is established in the process space for the components along a main flow direction. If the flow conditions are varied by varying the flow direction, the concentration gradient is also varied. As a result of the superposition of the concentration gradients, it is possible in total to achieve a more uniform deposition of layers, in particular a uniform layer thickness within a batch.
[0045] First and second feed and discharge lines may inherently be configured in any desired manner. Thus, the first and second feed/discharge lines may be configured in each case as two lines opening into the process space. In each case, one of the lines acts as the feed line and the other as the discharge line. In this case, then, at least four lines open into the process space. However, feed and discharge lines may also be connected to the process space via a common access, so that only two lines open into the process space. It is also possible, however, for the feed and discharge lines to also be configured in the form of injectors as a plurality of feed and discharge lines in order, by way of example, to obtain a uniform flow of the process gas in the process space. In order to produce a flow in the process space, provision is correspondingly made of a device for producing a process gas flow, which is connected to the first and/or second feed/discharge line. Pumps are generally used for this, as are also customary in the furnaces used hitherto. The flow can be produced, for example, by forcing the process gas into the process space or by pumping the process gas out of the process space.
[0046] In order to achieve a flow reversal of the process gas, devices for regulating the magnitude and the flow direction of the process gas flow is provided. These may be valves, for example, for opening or closing the first and second feed/discharge lines. It is also possible, however, to influence the main flow direction using the device for producing a process gas flow, e.g. by correspondingly regulating the conveying capacity of a pump. The device for regulating the magnitude and the flow direction may be controlled in a computer-aided manner, for example.
[0047] Preferably, the first and second feed/discharge line are arranged at opposite sides of the process space. A reversal through 180° is then effected in the event of a change in the flow. This is particularly advantageous in multiwafer installations, since the concentration gradients are particularly pronounced here. First and second feed/discharge lines are advantageously provided at the underside and top side of the process space, that is to say in the lengthening of a boat that is arranged in the process space and is charged with wafers.
[0048] In accordance with a further embodiment, an interval regulating unit is provided, for changing the direction of the process gas flow at intervals according to a variable time pattern. As a result, in accordance with the course of the method, it is possible to realize suitable time windows for the individual deposition intervals. As already explained for the method, it may be advantageous at the beginning of a deposition cycle to provide a high frequency for the change in the main flow direction in order first to produce a thin starter layer uniformly on all the semiconductor substrates. This starter layer then acts as a seed layer for the subsequent deposition of the layer. Once a uniform layer growth has been initiated on the entire surface of the individual semiconductor substrates, it is also possible to use a lower frequency for changing the main flow direction. In this way, it is also possible to produce thicker layers with thicknesses of several micrometers, in which only slight fluctuations in the layer thickness within a batch are observed.
[0049] In order to be able to precisely control the growth of the layer, in accordance with a further embodiment of the furnace, there is provided, a measuring unit for detecting the quantity and/or distribution of the components deposited onto the semiconductor substrates. This measuring unit can be connected to the device for producing a process gas flow in order to control the process gas flow or the concentration of the components supplied.
[0050] In accordance with a preferred embodiment of the furnace, there is provided, a control unit connected to the measuring unit and serving for the online control of the device for producing a process gas flow. On the basis of the data determined by the measuring unit, it is then possible automatically to intervene in the deposition process and thus to influence the growth of the layer.
[0051] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0052] Although the invention is illustrated and described herein as embodied in a method and furnace for the vapor phase deposition of components onto semiconductor substrates with a variable main flow direction of the process gas, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0053] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] [0054]FIG. 1 is a diagrammatic illustration of a furnace;
[0055] FIGS. 2 A- 2 D are diagrammatic illustrations of a furnace;
[0056] [0056]FIG. 3 is a graph of the layer thickness distribution in a batch obtained when carrying out the method; and
[0057] [0057]FIG. 4 is a graph of the layer thickness distribution in a batch obtained when carrying out a prior art method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a diagrammatic illustration of a longitudinal section through a furnace 1 . A process space 3 delimited by a partition 2 is arranged within the furnace 1 . By way of example, a heating device 16 may be arranged behind the partition 2 . Situated in the process space 3 is a boat 4 , which includes a rack in which wafers are arranged one above the other at a short distance. For the sake of clarity, the rack and the wafers are not illustrated in detail. Dummy wafers 5 are arranged in the outer sections of the boat 4 , that is to say at the top side and underside thereof, which dummy wafers 5 on both sides delimit the stack of the wafers 6 to be processed. The dummy wafers 5 serve for producing uniform flow conditions in the region of the wafers 6 to be processed. A first feed/discharge line 7 is provided at the underside of the process space 3 , through which line 7 process gas can be supplied to the process space 3 and process gas can be conducted out of the process space 3 . In order to be able to influence the flow of the process gas, a valve 8 is provided. The opening and closing of the valve 8 is controlled by a regulating unit 9 , which is connected to the valve 8 via control lines 10 .
[0059] Finally, a pump 11 is provided for producing a gas flow. The pump 11 can either convey process gas into the process space 3 or extract process gas from the latter, via the first feed/discharge line 7 . The operating state of the pump 11 is likewise controlled by the regulating unit 9 , which is connected to the pump 11 by corresponding control lines 10 . A second feed/discharge line 12 is arranged at the side of the process space 3 that is opposite to the first feed/discharge line 7 . The gas flow through the second feed/discharge line 12 can be regulated by valve 13 , which is controlled by the regulating unit 9 . The regulating unit 9 is connected to the valve 13 via control line 10 . The pump 14 can supply process gas to the process space 3 or discharge process gas from the process space 3 , via the second feed/discharge line 12 .
[0060] When the inventive method is carried out, first the valve 8 is opened by the regulating unit 9 and process gas is conveyed into the process space 3 by the pump 11 . Furthermore, valve 13 is opened and process gas is extracted from the process space 3 by the pump 14 . The process gas flows through the first feed/discharge line 7 into the process space 3 . The process gas rises laterally upward past the boat 4 , and a main flow direction 15 is formed. From the process gas flow ascending along the main flow direction 15 , portions diffuse away to the side into the interspaces between the wafers of the boat 4 that are arranged one above the other. In this case, the process gas flow is continuously depleted of the components that are deposited on the surface of the wafers, so that a concentration gradient is formed along the main flow direction 15 . Finally, the process gas flow leaves the process space 3 through the second feed/discharge line 12 and is extracted using the pump 14 . After a specific time period has elapsed, under the regulation of the regulating unit 9 , the valves 8 , 13 are closed and the pumps 11 , 14 are stopped. The pumps 11 , 14 are then switched such that the pump 14 conveys process gas into the process space 3 , while the pump 11 extracts process gas from the process space 3 . After the valves 8 , 13 have been opened, the process gas then flows from above into the process space 3 , so that the main flow direction 15 is reversed. As a consequence, a concentration gradient running in the opposite direction is formed, i.e. the greatest layer thickness growth is now observed at the upper end of the boat 4 , where initially the least layer thickness growth took place. As a result, it is possible to compensate for differences in the layer thickness growth between individual wafers of the boat 4 , so that within a batch, the fluctuations in the layer thickness can be considerably reduced.
[0061] A measuring unit 17 can detect a quantity and/or a distribution of the components deposited onto the semiconductor substrate 6 . A control unit 18 is connected to the measuring unit 17 . The control unit 18 is for an online control of the pumps 11 , 14 .
[0062] FIGS. 2 A- 2 D diagrammatically show various steps performed in one embodiment of the inventive method. The arrangement of the first and second feed/discharge lines 7 , 12 in the furnace 1 illustrated in FIGS. 2 A- 2 D differs from that shown in the furnace 1 illustrated in FIG. 1. In the furnace 1 illustrated in FIGS. 2 A- 2 D, the process gas flow is deflected at the upper end of a partition 2 and then guided downward laterally at the partition 2 . As a result, the connections for the first and second feed/discharge lines 7 , 12 can all be arranged at the underside of the furnace 1 . The valves and the regulating unit for controlling the process gas flow are not illustrated for the sake of clarity. In the first method step, as illustrated in FIG. 2A, process gas is introduced into the process space 3 via the first feed/discharge line 7 , rises upward past the boat 4 and is deflected at the upper end of the partition 2 in order then to be guided downward and finally led away via the second feed/discharge line 12 . After a specific time period has elapsed, the supply of the process gas is interrupted while the process gas, as shown in FIG. 2B, continues to be pumped away from the process space 3 via the second feed/discharge line 12 . Process gases still present in the process space 3 are therefore essentially removed. As an alternative, the process space 3 can also be flushed with an inert gas. Finally, as illustrated in FIG. 2C, the process gas is introduced into the process space 3 through the second feed/discharge line 12 and is discharged from the process space 3 through the first feed/discharge line 7 , so that the main flow direction is reversed in the process space 3 . After a specific time period has elapsed, the supply of the process gas is interrupted again while the process gas, as shown in FIG. 2D, continues to be extracted from the process space 3 via the first feed/discharge line 7 . After spent process gases have been extracted again, as illustrated in FIG. 2D, the cycle illustrated in FIGS. 2 A-D can be carried out again, if appropriate.
[0063] [0063]FIG. 3 diagrammatically shows the distribution of the layer thickness produced during the individual process stages of the method. In this case, the ordinal number of the wafer 6 within the stack is specified on the X axis. The wafer 1 is arranged at the lower end in FIG. 1, while the wafers with higher numbers are arranged correspondingly further up in the boat 4 . The layer thickness growth is specified on the Y axis. If the process gas is introduced into the process space 3 through the first feed/discharge line 7 and passed out of the process space through the second feed/discharge line 12 , then a higher layer thickness growth takes place on wafers with a low ordinal number than on wafers with a high ordinal number since the former are arranged nearer to the first feed/discharge line 7 , and the process gas flow has a high concentration of the component to be deposited. If the layer thickness growth is measured, then curve “A” illustrated in FIG. 3 is obtained. After reversing the flow direction, the process gas then flows into the process space through the second feed/discharge line 12 and is passed out again via the first feed/discharge line 7 . The wafers with a high ordinal number then correspondingly experience a more pronounced layer thickness growth than the wafers with a low ordinal number. If the layer thickness growth is measured, curve “B” illustrated in FIG. 3 is correspondingly obtained. Since the two curves “A” and “B” are ultimately added, curve “C” is obtained after carrying out the method.
[0064] [0064]FIG. 4 shows the distribution of the layer thickness when carrying out a prior art method for depositing a layer on a wafer. The same apparatus as illustrated in FIG. 1 is used, but the main flow direction is not varied. Therefore, during the entire deposition, the process gas is introduced into the process space 3 at the feed line 7 and, after it has flowed through the process space 3 along a main flow direction 15 , the process gas is discharged from the process space 3 at the discharge line 12 . As described above, a concentration gradient is established along the main flow direction 15 and leads to a different layer thickness growth on the wafers 6 arranged in the process space 3 . Wafers 6 that are arranged nearer to the feed line 7 experience a higher layer thickness growth than wafers 6 that are arranged nearer to the discharge line 12 . The distribution of the layer thickness is illustrated in FIG. 4. In this case, as in FIG. 3, the wafer number is plotted on the abscissa and the layer thickness is plotted on the ordinate. A curve “D” is obtained, which essentially corresponds to the curve A from FIG. 3. If the layer thicknesses of the wafers 6 are compared after the end of the layer deposition, curve “C” from FIG. 3 exhibits significantly smaller deviations in the layer thickness in comparison with curve “D” shown in FIG. 4.
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The invention relates to a method and to a furnace for the vapor phase deposition of components onto semiconductor substrates. The main flow direction of the process gases can be varied or reversed in the course of the method. This prevents temperature and concentration inhomogeneities of the process gas within the furnace, and the components to be uniformly deposited onto the semiconductor substrates.
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BACKGROUND OF THE INVENTION
The present invention relates to boats using steerable trolling motors and more particularly to a means for steering such a motor which leaves the occupant of the boat free to use his hands. Even more particularly my invention may be described as a seat controlled means for steering the motor.
The modern fishermen, particularly bass fishermen, are no longer content to float lazily along in pursuit of their angling pleasure. Since at least the late 1960's, these fishermen have used lightweight battery powered electric motors, commonly termed trolling motors, to move their boats across the water. The early trolling motors were manually steerable by means of a handle similar to that common to manually steerable outboard motors. Inasmuch as the fishermen also prefer to use spin-casting or bait casting fishing gear, the manual steering feature was not very convenient because two hands are necessary to operate the fishing gear and one hand is necessary to steer the trolling motor. A solution to this problem was provided by foot controlled trolling motors. These motors utilize a pivotally mounted foot plate attached to one end of a control cable which is attached at its opposite end to the motor and which steers the motor in response to pressure applied to the foot pedal by the operator. This system is adequate in its intended function; however it, too, limits the freedom of movement of the operator.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a trolling motor steering mechanism which gives the fisherman/operator maximum freedom of movement in his boat.
Another object of the invention is to allow the fisherman/operator to face in a selected direction while fishing without moving his control apparatus from one side of the boat to the other.
To accomplish these objectives my invention utilizes the seat mounting structure of the boat. The seat in the typical fishing boat is pedestal mounted for rotation (about a vertical axis), so that the fisherman may turn in any direction he wishes. To allow the fisherman unfettered mobility, I attach a steering cable to a steering arm which moves in the same arc as the seat. I also provide a release mechanism which allows the seat to turn without displacing the steering arm, thus the fisherman is then free to turn without altering the course of the boat or without moving the motor when the motor is not on.
DESCRIPTION OF THE DRAWINGS
Apparatus embodying features of my invention are illustrated in the accompanying drawings which form a portion of this application wherein:
FIG. 1 is an elevational view, partly broken away and in section, showing my mounting structure in a boat;
FIG. 2 is an exploded view of one embodiment of the pedestal attachment used in my invention;
FIG. 3 is an elevational view, partly in section, showing the control arm bracket;
FIG. 4 is a fragmental, sectional view, of another embodixent of my invention; and
FIG. 5 is a perspective view, partly broken away and in section, of yet another embodiment of my invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a trolling motor 11 is conventionally mounted at the bow of the boat 12, such that its power unit 13 is supported by a shaft 14. A steering collar 16 fits around the upper portion of the shaft 14 and rotates the shaft 14 in accordance with the positioning of a cable 17 connected thereto as is well known in the art. The cable 17 is a commonly used control cable having an outer sleeve 18 and an inner wire-like member 19. The other end of the cable 17 is attached to a steering arm 21. The sleeve 18 extends through an aperture 22 in a steering arm bracket 23, as shown in FIG. 3. A set screw 24 holds the sleeve 18 motionless as the inner member 19 moves in response to movement of the steering arm 21. A connector fitting 25, such as a clevis and pin assembly, attaches the steering arm 21 to the inner member 19. The bracket 23, which is mounted to the floor of the boat 12, serves to limit the motion of the steering arm 21 to a predetermined arc between the opposite ends thereof.
The steering arm 21 extends radially from a seat support column 26, as shown in FIGS. 1, 2 and 5. The column 26 is mounted for rotation on a base 27 such as through the use of an axial mounting pin 28 extending into the base 27. In the embodiment shown in FIG. 2 the upper portion of column 26 has a generally cylindrical cavity 29 therein. Secured to and extending radially from the column 26 and communicating at one end with the cavity 29 by a port 29 a is a sleeve 31. Within sleeve 31 is an elongated locking pin 32 which is urged toward the cavity 29 by a spring 33 mounted coaxially on the pin 32 and captured within the sleeve 31 by an end cap 34. The locking pin 32 extends through an aperture in the end cap 34 and is attached to a locking lever 36 by a pivotal roll pin connection. Lever 36 is adapted to compress spring 33 and withdraw pin 32 from cavity 29 as the lever is selectively moved from a locked to unlocked position.
Telescoping within cavity 29 is a cylindrical seat support 37 which is of a size to match cavity 29. Mounted at the top of the seat support 37 is a seat bracket 38 which secures the seat, indicated at 35, to the seat support 37. The seat support 37 hs a plurality of angularly spaced recesses 39 therein which receive the end of the locking pin 32 when lever 36 is in the locked position. Although any number of recesses 39 may be employed, three recesses evenly spaced over an arc of 130° have proven adequate. The clindrical end of the seat support 37 may be lubricated to facilitate rotation in the cavity 29.
In a second embodiment, shown in FIG. 4, the seat support 41 telescopies over the column 26 and carries the locking pin 32 and its associated mechanism. In this embodiment the recesses 39 are formed in column 26 and the seat support 41 is carried by a thrust bearing 42 at the upper end thereof.
In another embodiment, shown in FIG. 5, the column 26 carries an annular flange 46 which has a plurality of apertures 47 therethrough. The seat bracket 38 is rotatably mounted on the column 26 as by a bearing 50 and has a single recess 53 which aligns vertically with selected ones of the apertures 47 upon rotation of the seat. A mounting bracket extension 49 extends beneath the seat and carries a locking rod 48 which is mounted in journals 51, as shown. The locking rod is formed such that one end thereof serves as a locking pin 32 which extends upwardly toward the bottom of the seat while the remainder of the rod 48 extends generally horizontally. The pin 32 is connected to a first leg 54 which is offset from a pivot region 56 which is held in the journals 51. A second leg 57, also offset from the pivot region 56, carries a handle 58 at its distal end. Vertical movement of the handle 58 causes corresponding movement of the pin 32 such that the pin 32 is inserted and retracted from the apertures 47 and recess 53. The rod 58 is normally biased for engagement at pin 32 with an aperture 47 and recess 56 by suitable means, such as a leaf spring or tension spring, shown generally at 52.
Each embodiment of my invention operates in the same way. That is, the locking pin 32 is baised toward engagement with the apertures 47 and recess 53 and locks the seat support to the column. In this condition the steering arm 21 moves through the same arc as the seat and registers the same angular displacement. This angular displacement is transmitted to the steering collar 16 so that when the seat turns the trolling motor 11 also turns. When the locking pin 32 is retracted the seat is free to turn without turning the column 26 or the motor 11. By engaging the locking pin through one of the offset apertures 47 and the recess 53, the fisherman may face outboard of the boat 12 while he steers the boat with his seat. This allows him to comfortably fish toward the shoreline or any other fish cover while maintaining complete control of the boat. It should be noted that the trolling motor 11 has on/off and speed controls which can be conveniently mounted either to a cover, not shown, on the steering arm bracket 23 or at any other convenient location.
While I have shown my invention in various forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.
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A steering apparatus for a trolling motor utilizes a rotatable pedestal to support a boat occupant seat. The seat is detachably connected to the pedestal for rotation therewith and the pedestal is connected to the trolling motor by a control cable for changing the direction of the motor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/EP2004/008336, filed Jul. 26, 2004, published in French as WO 2005/028526 on March 31, 2005, which claims priority to French Application No. 03/9930, filed Aug. 13, 2003, the disclosures of both applications being incorporated herein in their entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to a catalytic system usable for the copolymerization of at least one conjugated diene and at least one monoolefin, to a process for preparing this catalytic system, to a process for preparing a copolymer of at least one conjugated diene and at least one monoolefin involving the use of said catalytic system, and to such a copolymer. The invention applies in particular to the copolymerization of a conjugated diene with an alpha-olefin and/or ethylene.
[0004] 2. Description of Related Art
[0005] It has long been difficult to carry out the copolymerization of a conjugated diene and a monoolefin, such as an alpha-olefin (i.e. comprising by definition at least three carbon atoms, unlike ethylene which is not an alpha-olefin), due to the different coordination indices exhibited by conjugated dienes and monoolefins with regard to Ziegler Natta type catalytic systems based on transition metals.
[0006] It has been known since the 1970s to prepare alternating copolymers of a conjugated diene, such as butadiene or isoprene, and an alpha-olefin, such as propylene, by means of such catalytic systems based on vanadium or titanium. Reference will be made, for example, to the article “Furukawa, J. in Alternating Copolymers, Cowie, J. M. G., ed.; Plenum Press: New York, 1985; pp. 153-187” which mentions the use of a catalytic system based on a derivative of vanadium and an aluminum compound for obtaining these copolymers.
[0007] One major disadvantage of these catalytic systems is that they must be prepared at very low temperatures (approximately −70° C.) and that they entail the use of a likewise low copolymerization temperature, being between −30° C. and −50° C. Using higher temperatures for the copolymerization results in deactivation of these catalytic systems and in a reduction in the molecular masses of the copolymers obtained.
[0008] In order to obtain alternating copolymers of butadiene and propylene exhibiting higher molecular masses with improved activity and greater control of the degree of alternation, German patent specification DE-A-270 6118 teaches the use of catalytic system comprising a vanadium dialkoxyhalide and a trialkylaluminum.
[0009] One major disadvantage of these catalytic systems based on vanadium is again that copolymerization must be carried out at low temperature.
[0010] Non-alternating conjugated diene/alpha-olefin copolymers, such as butadiene/propylene or butadiene/ethylene/propylene copolymers, have also been produced in the past, the copolymerization reactions being performed at temperatures higher than ambient temperature. To this end, use has been made either of homogeneous catalytic systems based on a halogenated trialkylaluminum and a vanadium derivative (see German patent specifications DE-A-253 4496 and DE-A-200 1367 which relate to obtaining butadiene/ethylene/propylene terpolymers with a reduced content of trans-1,4 butadiene units) or of a derivative of titanium and phosgene (see the article “Furukawa, J. et al., J. Polym. Sci., Polym. Chem. Ed. 1973, 11, p. 629” which relates to obtaining random copolymers), or of catalytic systems based on TiCl 4 supported on a magnesium halide (see European patent specification EP-A-171 025).
[0011] It will be noted that these latter supported catalytic systems have the twin drawback of giving rise, on the one hand, to the formation of a gel in the resultant copolymers and, on the other hand, to reduced molar contents of inserted butadiene, typically of less than 15%.
[0012] The attempt has also been made to prepare butadiene/ethylene/propylene terpolymers by means of homogeneous catalytic systems comprising conventional metallocenes of group IV of the periodic table which satisfy the formula Cp 2 MX 2 (see international patent specification WO-A-88/04672 and the article “Galimberti et al., Makromol. Chem. 1991, 192, p. 2591”).
[0013] One major disadvantage of these catalytic systems of the formula Cp 2 MX 2 is that the butadiene considerably limits activity and is inserted in only very small quantities. It will be noted that the copolymers obtained in this manner comprise cyclic units (cyclopentane units).
[0014] European patent specification EP-A-891 993 proposes a catalytic system for the copolymerization of a monoolefin having 2 to 12 carbon atoms and at least one conjugated diene monomer, which system comprises constituent (a) below and at least one compound selected from among constituents (b), (c) and (d) below:
(a) a transition metal complex satisfying any one of the following formulae:
(Cp 1 -Z-Y)MX 1 X 2 or alternatively (Cp 1 Cp 2 -Z)MX 1 X 2 , where
M is any one of the following metals: Ti, Zr, Hf, Rn, Nd, Sm, Ru, Cp 1 and Cp 2 are each a cyclopentadienyl, indenyl or fluorenyl group, Y is a ligand containing an atom of oxygen, nitrogen, phosphorus or sulfur, Z represents C, O, B, S, Ge, Si, Sn or a group containing any one of these atoms, X 1 and X 2 each represent an anionic or neutral ligand which is a Lewis base; (b) a compound which reacts with the metal M of (a) to form an ionic complex; (c) an organoaluminum compound; and (d) an aluminoxane.
[0024] It will be noted that the copolymers obtained in this document EP-A-891 993 comprise a low molar content of inserted conjugated diene (less than 10%) and that they always comprise cyclic units (of the cyclopentane and cyclopropane type).
[0025] Catalytic systems specifically comprising a lanthanide complex and enabling the copolymerization of conjugated dienes and alpha-olefins have also been reported in the literature. Kaulbach et al. have described the copolymerization of butadiene/octene or dodecene with a neodymium octoate complex in Angew. Makromol. Chem. 1995, 226, p. 101. Visseaux M. et al have described the copolymerization of alpha-olefin/conjugated diene (butadiene or isoprene) with a lanthanide allyl complex in Macromol. Chem. Phys. 2001, 202, p. 2485.
[0026] One major disadvantage of these latter catalytic systems is that the molar content of inserted alpha-olefin is always low, being less than 20%.
[0027] It is furthermore known to copolymerise ethylene and a conjugated diene, such as butadiene, by means of halogenated lanthanide complexes which can be alkylated in situ in the polymerization medium via a co-catalyst. Accordingly, European patent specification EP-A-1 is 092 731 in the name of the present applicants teaches the use to this end of a catalytic system comprising:
[0028] on the one hand, an organometallic complex represented by one of the following formulae:
[0029] where Ln represents a lanthanide metal having an atomic number which may range from 57 to 71,
[0030] where X represents a halogen which may be chlorine, fluorine, bromine or iodine,
[0031] where, in the formula A′, two ligand molecules Cp 1 and Cp 2 , each consisting of a substituted or unsubstituted cyclopentadienyl or fluorenyl group, are attached to the metal Ln,
[0032] where, in the formula B′, a ligand molecule consisting of two substituted or unsubstituted cyclopentadienyl or fluorenyl groups Cp 1 and Cp 2 linked to one another by a bridge P of the formula MR 2 , where M is an element from column IVa of Mendeleev's periodic table, and where R is an alkyl group comprising from 1 to 20 carbon atoms, is attached to the metal Ln and
[0033] on the other hand, a co-catalyst selected from the group comprising an alkylmagnesium, an alkyllithium, an alkylaluminum, a Grignard reagent and a mixture of these constituents.
SUMMARY OF THE INVENTION
[0034] The object of the present invention is to propose a novel catalytic system which remedies the above-stated drawbacks, and this object is achieved in that the applicants have surprisingly discovered that a catalytic system comprising:
[0035] (i) an organometallic complex represented by the following generic formula:
{[P(Cp)(Fl)Ln(X)(L x )} p (1)
[0036] where Ln represents a lanthanide atom of an atomic number from 57 to 71, to which is attached a ligand molecule comprising cyclopentadienyl Cp and fluorenyl Fl groups which are each independently substituted or unsubstituted and linked to one another by a bridge P of the formula MR 1 R 2 , where M is an element from column IVa of Mendeleev's periodic table and where R 1 and R 2 , which may be identical or different, each represent alkyl groups having from 1 to 20 carbon atoms or alternatively cycloalkyl or phenyl groups having from 6 to 20 carbon atoms,
[0037] where X represents a halogen atom which may be chlorine, fluorine, bromine or iodine,
[0038] where L comprises an optional complexing molecule, such as an ether, and optionally a substantially less complexing molecule, such as toluene,
[0039] where p is a natural integer greater than or equal to 1 and x is greater than or equal to 0, and
[0040] (ii) a co-catalyst belonging to the group consisting of alkylmagnesiums, alkyllithiums, alkylaluminums, Grignard reagents and mixtures of these constituents,
[0041] may be used to obtain a copolymer of a conjugated diene and at least one monoolefin, such as an alpha-olefin and/or ethylene, and more particularly a copolymer of at least one conjugated diene and at least one alpha-olefin having from 3 to 18 carbon atoms, said copolymer having a number-average molecular mass which may be greater than 30000 g/mol, or even than 60000 g/mol, and comprising units resulting from said conjugated diene(s) in a molar content of greater than 40% and units resulting from said alpha-olefin(s) in a molar content of greater than or equal to 10%.
DETAILED DESCRIPTION OF THE INVENTION
[0042] It will be noted that said organometallic complex may be activated in situ in the polymerization medium via said co-catalyst, which has the twin function of creating a metal-carbon bond and of purifying the polymerization medium.
[0043] Said organometallic complex is, for example, represented by the following formula:
[0044] According to one embodiment of the invention, said organometallic complex is such that p equals 2, in which case it is a dimer represented by the following formula:
[0045] Likewise preferably, said cyclopentadienyl Cp and fluorenyl Fl groups are both unsubstituted in either of the above-stated formulae, respectively satisfying the formulae C 5 H 4 and C 13 H 8 .
[0046] Likewise preferably in relation to any one of the above-stated features according to the invention, said bridge P satisfies the formula SiR 1 R 2 . Still more preferably, R 1 and R 2 are each independently alkyl groups, such as methyl groups.
[0047] Likewise preferably in relation to any one of the above-stated features according to the invention, said organometallic complex is such that the lanthanide Ln is neodymium.
[0048] Likewise preferably in relation to any one of the above-stated features according to the invention, said co-catalyst is an alkylmagnesium such as butyloctylmagnesium, or a mixture of an alkylaluminum such as diisobutylaluminum hydride and an alkyllithium such as butyllithium which are present in this mixture in substantially stoichiometric quantities.
[0049] Likewise preferably in relation to any one of the above-stated features according to the invention, the (co-catalyst/organometallic complex) molar ratio is less than or equal to 5, such that said resultant copolymer may have a number-average molecular mass Mn of greater than 30,000 g/mol.
[0050] Still more preferably, said (co-catalyst/organometallic complex) molar ratio is less than or equal to 2, such that said resultant copolymer may have a number-average molecular mass Mn of greater than 60,000 g/mol.
[0051] A process for preparation according to the invention of said catalytic system comprises:
[0052] a) preparation of said organometallic complex comprising:
(i) reaction with an alkyllithium of a hydrogenated ligand molecule, represented by formula (2) below, in order to obtain a lithium salt satisfying the formula (3) below:
(ii) reaction in a complexing solvent of said salt with an anhydrous trihalide of said lanthanide of the formula LnX 3 where X is said halogen, (iii) evaporation of said complexing solvent, then extraction of the product obtained in (ii) in a solvent which is substantially less complexing than the solvent used in (ii), then, optionally, (iv) crystallization of the product extracted in (iii) in order to obtain said organometallic complex from which said complexing solvent is completely absent, then
[0057] b) addition of said co-catalyst to said organometallic complex prepared in a).
[0058] Preferably, at least one of the following conditions prevails:
said alkyllithium used in a) (i) is butyllithium, and/or said complexing solvent used in a) (ii) is tetrahydrofuran, and/or said substantially less complexing solvent used in a) (iii) is heptane (virtually non-complexing) or toluene (“moderately” complexing).
[0062] Preferably, this process is such that said cyclopentadienyl Cp and fluorenyl Fl groups are both unsubstituted, respectively satisfying the formulae C 5 H 4 and C 13 H 8 .
[0063] Likewise preferably in relation to any one of the above-stated features, this process is such that said bridge P satisfies the formula SiR 1 R 2 .
[0064] Still more preferably, this process is such that R 1 and R 2 are each independently alkyl groups, such as methyl groups.
[0065] Likewise preferably in relation to any one of the above-stated features, this process is such that said lanthanide Ln is neodymium.
[0066] Likewise preferably in relation to any one of the above-stated features, this process is such that said co-catalyst is an alkylmagnesium such as butyloctylmagnesium, or a mixture of an alkylaluminum such as diisobutylaluminum hydride and an alkyllithium such as butyllithium, which are present in said mixture in substantially stoichiometric quantities.
[0067] Likewise preferably in relation to any one of the above-stated features, this process is such that the molar ratio (number of moles of said co-catalyst/number of moles of said organometallic complex) is less than or equal to 5, the catalytic system being usable such that the copolymer has a molecular mass Mn of greater than 30,000 g/mol.
[0068] Still more preferably, this process is such that said (co-catalyst/organometallic complex) molar ratio is less than or equal to 2, the catalytic system being usable such that copolymer has a molecular mass Mn of greater than 60,000 g/mol.
[0069] A process according to the invention for preparing a copolymer of at least one conjugated diene and at least one monoolefin comprises the reaction of said catalytic system as defined previously in an inert hydrocarbon solvent, in the presence of said conjugated diene(s) and said monoolefin(s).
[0070] Preferably, this process is such that said copolymer comprises units resulting from a conjugated diene, such as butadiene or isoprene, and units resulting from at least one monoolefin belonging to the group consisting of ethylene, alpha-olefins and vinyl aromatic compounds.
[0071] Advantageously, in relation to any one of the above-stated features, this process is such that said copolymer comprises units resulting from an alpha-olefin having from 3 to 18 carbon atoms in a molar content of greater than or equal to 10%, or alternatively that it comprises units resulting from ethylene and, in a molar content of greater than or equal to 10%, units resulting from an alpha-olefin having from 3 to 18 carbon atoms.
[0072] In either of the latter two cases, this process is advantageously such that the units resulting from said conjugated diene are present in said copolymer in a molar content of greater than 40%, preferably of greater than 50%.
[0073] Advantageously, in relation to any one of the above-stated features, this process is such that the units resulting from said conjugated diene(s) have a trans-1,4 linkage content of greater than 70%.
[0074] Advantageously, in relation to any one of the above-stated features, this process is such that the (co-catalyst/organometallic complex) molar ratio is less than or equal to 5, such that the molecular mass Mn of the copolymer is greater than 30,000 g/mol.
[0075] Still more advantageously, this process is such that said (co-catalyst/organometallic complex) molar ratio is less than or equal to 2, such that said copolymer has a molecular mass Mn of greater than 60,000 g/mol.
[0076] A copolymer of at least one conjugated diene and at least one alpha-olefin having from 3 to 18 carbon atoms according to the invention is capable of being obtained by a copolymerization process as defined previously, and this copolymer according to the invention is preferably such that it simultaneously fulfils the following conditions:
[0077] the number-average molecular mass of said copolymer is greater than 60,000 g/mol,
[0078] said copolymer comprises units resulting from said conjugated diene(s) in a molar content of greater than 40% and less than or equal to 90%, and units resulting from said alpha-olefin(s) in a molar content of less than 60% and greater than or equal to 10%,
[0079] said units resulting from said conjugated diene(s) have a trans-1,4 linkage content of greater than 70%, and
[0080] said copolymer is devoid of cyclic units.
[0081] According to an advantageous embodiment of the invention in relation to either one of the above-stated two features, said copolymer consists of a copolymer of a conjugated diene, such as butadiene or isoprene, and an alpha-olefin having from 3 to 18 carbon atoms, such as propene, butene, hexene or octene.
[0082] Still more preferably, said copolymer according to the invention comprises the units resulting from said conjugated diene(s) in a molar content of greater than 60% and less than or equal to 80%, and the units resulting from said alpha-olefin(s) in a molar content of less than 40% and greater than or equal to 20%.
[0083] According to an advantageous variant of the invention, said copolymer is consists of a terpolymer of a conjugated diene, such as butadiene or isoprene, of ethylene and of an alpha-olefin of 3 to 18 carbon atoms, such as propene, butene, hexene or octene.
[0084] According to another feature of the invention, said copolymer is such that each unit resulting from said alpha-olefin(s) is inserted in the chain of said copolymer between two units resulting from said or each conjugated diene, such that the overall set of the units of said copolymer exhibits a regular distribution of the practically alternating kind (also known as “pseudo-alternating” by the person skilled in the art).
[0085] The above-stated features of the present invention, as well as others, will be better understood on reading the following description of several embodiments of the invention, which are given by way of non-limiting illustration, in comparison with two final comparative examples illustrating the prior art.
[0086] All the following Examples were performed under argon and the solvents were previously dried with a 3 Å molecular sieve under a stream of argon. The liquid alpha-olefins together with the styrene were dried over CaH 2 or NaH and then distilled.
[0087] The microstructure of the copolymers obtained in these Examples was determined using 1 H NMR and 13 C NMR techniques. A “BRUKER DRX 400” spectrometer was used for this purpose at a frequency of 400 MHz for the 1 H NMR and of 100.6 MHz for the 13 C NMR. Reference will be made to the attached appendix for a description of these methods.
[0088] Glass transition temperatures were measured by DSC (Differential Scanning Calorimetry) using a “Setaram DSC 131” apparatus. The temperature program used corresponds to a rise in temperature from −120° C. to 150° C. at a rate of 10° C./min.
[0089] The molecular masses Mn and Mw (average molecular masses in number and weight) and polydispersity indices (Ip=Mw/Mn) were determined by size-exclusion chromatography using the apparatus and under the analytical conditions described below. The molecular masses values stated in the following Examples are stated as polystyrene equivalents.
[0090] Apparatus: Waters, 515 HPLC (pump) and IR 410 (detector).
[0091] Columns: 1 “Waters Styragel HR 4E” column +2 “Waters Styragel HR 5E” columns.
[0092] Temperature: T(column)=45° C., T(detector)=40° C.
[0093] Solvent: THF.
[0094] Elution rate: 1 ml/min.
[0095] Standards: Polystyrene (Mn: 580 to 3,150,000 g/mol).
EXAMPLE 1
Synthesis of the Organometallic Complex [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x
Synthesis of the Ligand Me 2 Si(C 5 H 5 )(C 13 H 9 )
[0096] The ligand Me 2 Si(C 5 H 4 )(C 13 H 9 ), where Me denotes a methyl group, was synthesized according to an operating method described in the literature (Alt et al J. Organomet. Chem. 1996, 509, pp. 63-71).
Synthesis of the Salt [Me 2 Si(C 5 H 4 )(C 13 H 8 )]Li 2 (OC 4 H 8 ) 2
[0097] 12.1 ml of 1.6 M BuLi are added at ambient temperature to a solution of 2.8 g of the ligand Me 2 Si(C 5 H 5 )(C 13 H 9 ) in 150 ml of THF. The solution is stirred for 4 h, then the THF is evaporated. The residue is dried in a vacuum then washed while cold with two 50 ml portions of heptane. A yellow solid is isolated. 1 H NMR analysis of this solid was performed with a “BRUKER 300 MHz” spectrometer in the range THF-d8: δ(chemical shift in ppm)=
[0098] 7.85 (d, J 8 Hz, 2H, Fl),
[0099] 7.77 (d, J 8 Hz, 2H, Fl),
[0100] 6.79 (dd, J 8 Hz and 7 Hz, 2H, Fl),
[0101] 6.44 (dd, J 8 Hz and 7 Hz, 2H, Fl),
[0102] 6.15 (m, 2H, Cp),
[0103] 5.83 (m, 2H, Cp),
[0104] 3.62 (THF),
[0105] 1.78 (THF),
[0106] 0.67 (s, 6H, SiMe 2 ).
[0107] The structure of the salt obtained is [Me 2 Si(C 5 H 4 )(C 13 H 8 )]Li 2 (OC 4 H 8 ) 2 .
Synthesis of the Organometallic Complex [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x
[0108] 0.58 g (2.3 mmol) of NdCl 3 are stirred overnight while being refluxed in 50 ml of THF. A solution of 0.82 g of the salt [Me 2 Si(C 5 H 4 )(C 13 H 8 )]Li 2 (OC 4 H 8 ) 2 in 50 ml of THF is added at −20° C. to the resultant suspension. The solution formed is then stirred for 24 h at ambient temperature. The THF is evaporated and the residue is taken up in toluene. The salt (LiCl) is filtered out and the organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x is recovered by evaporation of the toluene.
EXAMPLE 2
Copolymerization of Butadiene and Ethylene by Means of the Organometallic Complex of Example 1 and Various Co-Catalysts
[0109] Three tests according to the invention of the copolymerization of ethylene and butadiene were performed according to the operating method described below, together with a “control” test of the homopolymerization of ethylene.
[0110] A solution composed of 300 ml of toluene, a specific quantity x c (mg) of the organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x prepared in Example 1 and of a co-catalyst according to the invention and then a mixture of ethylene and butadiene with a molar fraction y (%) of butadiene were introduced in succession into a reactor under an argon atmosphere. The internal pressure of the reactor was maintained at 4 bar when the fraction y of butadiene so permits. The temperature of the polymerization reactor was maintained at 80° C. for the polymerization.
[0111] After a reaction time t (min.), polymerization is terminated by cooling and degassing the reactor, then the copolymer is obtained by precipitation in methanol. After drying, a mass m (g) of copolymer comprising units resulting from butadiene according to a molar fraction z (%) is obtained.
[0112] The co-catalyst used was butyloctylmagnesium (hereinafter abbreviated to “BOMAG”) or a mixture of butyllithium (“BuLi”) and diisobutylaluminum hydride (“DiBAH”) with the following molar proportions:
[0113] neodymium/BuLi/DiBAH=1/10/10, and neodymium/BOMAG=1/20
[0114] (i.e. 20 molar equivalents of co-catalyst relative to the neodymium).
[0115] The four polymerization tests are described in Table 1 below.
TABLE 1 Butadiene insertion (molar content) % x c Co- m t y z % trans- Tests (mg) catalyst (g) (min) (%) (%) 1,2 1,4 2-1 34 BuLi/ 3.4 70 — — — — DiBAH 2-2 45 BuLi/ 4.2 50 20 28 4 96 DiBAH 2-3 40 BuLi/ 5.0 120 40 48 4 96 DiBAH 2-4 30 BOMAG 6.5 60 20 26 3 97
[0116] These results show that the ethylene/butadiene copolymers obtained in tests 2-2 to 2-4 comprise units resulting from butadiene according to a molar fraction z of greater than 20%, and that the molar content of trans-1,4 units for these units resulting from butadiene is greater than 90%.
EXAMPLE 3
Copolymerization of Butadiene and Octene by Means of the Organometallic Complex of Example 1 and Various Co-Catalysts
EXAMPLE 3-1
[0117] A solution composed of 10 ml of toluene, 100 ml of octene, 35 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10, and then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0118] After a reaction time of 7.5 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 11.4 g. The molecular mass Mn of the polymer was 11470 g/mol (Ip index=1.7). The glass transition temperature was −71.5° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0119] octene=32.0 mol% and butadiene=68.0%, with:
[0120] 1,2-butadiene=7.0% and 1,4-butadiene=93.0%, 96.0% of which was trans-1,4.
EXAMPLE 3-2
[0121] A solution composed of 10 ml of toluene, 100 ml of octene, 37 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a “BOMAG” co-catalyst, and then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0122] After a reaction time of 15 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 13.3 g. The molecular mass Mn of the polymer was 8960 g/mol (Ip index=1.8). The glass transition temperature was −65.4° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0123] octene=29.4% and butadiene=70.6%, with:
[0124] 1,2-butadiene=16.3% and 1,4-butadiene=83.7%, 97.5% of which was trans-1,4.
EXAMPLE 3-3
[0125] A solution composed of 10 ml of toluene, 100 ml of octene, 37 mg of said complex prepared in Example 1 and 5 molar equivalents relative to the neodymium of a “BOMAG” co-catalyst, and then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0126] After a reaction time of 15 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 13.1 g. The molecular mass Mn of the copolymer was 30650 g/mol (Ip index=2.3). The glass transition temperature was −69.0° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0127] octene=28.8% and butadiene=71.2%, with:
[0128] 1,2-butadiene=10.3% and 1,4-butadiene=89.7%, 96.6% of which was trans-1,4.
EXAMPLE 3-4
[0129] A solution composed of 10 ml of toluene, 100 ml of octene, 33 mg of said complex prepared in Example 1 and 2 molar equivalents relative to the neodymium of a “BOMAG” co-catalyst, and then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0130] After a reaction time of 15 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 6.8 g. The molecular mass Mn of the copolymer was 67350 g/mol (Ip index=1.9). The glass transition temperature was −69.6° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0131] octene=26.2% and butadiene=73.8%, with:
[0132] 1,2-butadiene=10.1% and 1,4-butadiene=89.9%, 93.8% of which was trans-1,4.
EXAMPLE 3-5
[0133] A solution composed of 200 ml of toluene, 50 ml of octene, 30 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a “BOMAG” co-catalyst, and then 30 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0134] After a reaction time of 22 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 7.6 g. The molecular mass Mn of the copolymer was 7120 g/mol (Ip index=2.0). The glass transition temperature was −64° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0135] octene=13.7% and butadiene=86.3%, with:
[0136] 1,2-butadiene=24.7% and 1,4-butadiene=75.3%, 95.2% of which was trans-1,4.
[0137] The results obtained from these tests 3-1 to 3-5 show that the copolymers obtained have a molar content of units resulting from octene which is between 10 and 60% and a molar content of units resulting from butadiene which is between 90 and 40%.
[0138] It will be noted that the units of these copolymers which result from butadiene have a molar content of trans-1,4 units which is always greater than 70%.
[0139] It will furthermore be noted that tests 3-3 and 3-4 advantageously give rise to octene/butadiene copolymers of a relatively high molecular mass Mn (greater than 30000 and 60000 g/mol respectively), due to the very low (co-catalyst/organometallic complex) molar ratio which was used (ratio equal to 5 and to 2 for these tests 3-3 and 3-4, respectively).
EXAMPLE 4
Copolymerization of Butadiene and Hexene by Means of the Organometallic Complex of Example 1 and a Co-Catalyst
[0140] A solution composed of 10 ml of toluene, 100 ml of hexene, 39 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10, and then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0141] After a reaction time of 17 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 18.9 g. The molecular mass Mn of the polymer was 17500 g/mol (Ip index=1.9). The glass transition temperature was −68.7° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0142] hexene=29.8% and butadiene=70.2%, with:
[0143] 1,2-butadiene=7.5% and 1,4-butadiene=92.5%, 95.0% of which was trans-1,4.
EXAMPLE 5
Copolymerization of Butadiene and Butene by Means of the Organometallic Complex of Example 1 and a Co-Catalyst
[0144] A solution composed of 100 ml toluene, 37 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a co-catalyst consisting of a “BuLi/DiBAH” mixture with neodymium/BuLi/DiBAH=1/10/10, and then 25 ml of butadiene and 25 ml of butene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0145] After a reaction time of 18 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 10.7 g. The molecular mass Mn of the copolymer was 13200 g/mol (Ip index=1.9). The glass transition temperature was −74.6° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0146] butene=18.6% and butadiene=81.4%, with:
[0147] 1,2-butadiene=9.6% and 1,4-butadiene=90.4%, 95.0% of which was trans-1,4.
EXAMPLE 6
Copolymerization of Butadiene and Hexadecene by Means of the Organometallic Complex of Example 1 and a Co-Catalyst
[0148] A solution composed of 10 ml of toluene, 100 ml of hexadecene, 32 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10, and then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0149] After a reaction time of 7 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C. and distillation of any residual hexadecene, the yield was 9.9 g. The molecular mass Mn of the copolymer was 21530 g/mol (Ip index=1.8). The glass transition temperature could not be determined due to a very wide melting range (Tf (peak summit)=−9° C.). Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0150] hexadecene=21.8% and butadiene=78.2%, with:
[0151] 1,2-butadiene=10.2% and 1,4-butadiene=89.8%, 93.8% of which was trans-1,4.
EXAMPLE 7
Copolymerization of Butadiene and Propene by Means of the Organometallic Complex of Example 1 and a Co-Catalyst
[0152] A solution composed of 450 ml toluene, 25 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10, 30 ml of butadiene together with an appropriate quantity of propylene to achieve a total pressure P=7 bar when T=80° C. were introduced in succession into a reactor under an argon atmosphere.
[0153] After a reaction time of 15 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 7.3 g. The molecular mass Mn of the copolymer was 9120 g/mol (Ip=2.0). The glass transition temperature was −75.3° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents): propene=35.8% and butadiene=64.2%, and
[0154] 1,2-butadiene=6.1%, 1,4-butadiene=93.9%, 97.4% of which was trans-1,4.
EXAMPLE 8
Copolymerization of Butadiene and Styrene by Means of the Organometallic Complex of Example 1 and a Co-Catalyst
[0155] A solution composed of 50 ml of toluene, 50 ml of styrene, 30 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a “BOMAG” co-catalyst, and then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0156] After a reaction time of 14 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 46.4 g. The molecular mass Mn of the copolymer was 25900 g/mol (Ip index=2.0). The glass transition temperature was +16° C. Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0157] styrene=57% and butadiene=43%, with 1,4-butadiene=100%, of which 100% was trans-1,4.
EXAMPLE 9
Terpolymerization of Butadiene, Ethylene and Octene by Means of the Organometallic Complex of Example 1 and a Co-Catalyst
[0158] A solution composed of 10 ml of toluene, 100 ml of octene, 37 mg of said complex prepared in Example 1 and 20 molar equivalents relative to the neodymium of a co-catalyst consisting of a “BuLi/DiBAH” mixture with neodymium/BuLi/DiBAH=1/10/10, then 25 ml of butadiene and finally a quantity of ethylene so as to obtain a total pressure in the reactor of P=4.5 bar when the temperature T was 80° C. were introduced in succession into a reactor under an argon atmosphere. The internal pressure of the reactor was then maintained at 4.5 bar.
[0159] After a reaction time of 3.5 h, polymerization was terminated by cooling and degassing the reactor, then the terpolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 25.7 g. The molecular mass Mn of the terpolymer was 13300 g/mol (Ip index=2.9). The glass transition temperature was −78° C. Analysis of the terpolymer by 13 C and 1 H NMR was as follows (molar contents):
[0160] octene=14.4%, ethylene=28.8% and butadiene=56.8%, with
[0161] 1,2-butadiene=5.7% and 1,4-butadiene=94.3%, 99.3% of which was trans-1,4.
COMPARATIVE EXAMPLE 10
Copolymerization of Butadiene/Hexene and Terpolymerization of Ethylene/Butadiene/Hexene by Means of a Known Organometallic Complex and a Co-Catalyst
[0162] The catalytic system used is one of those described in the above-stated patent specification EP-A-1 092 731 as being usable for the copolymerization of ethylene and butadiene.
[0163] This catalytic system comprises an organometallic complex of the formula [Me 2 Si(Me 3 SiC 5 H 3 ) 2 ]NdCl, where Me denotes a methyl group, and a BuLi/DiBAH co-catalyst.
[0164] It will be noted that this organometallic complex comprises two substituted cyclopentadienyl groups, unlike the organometallic complex according to the invention which specifically comprises one cyclopentadienyl group and one fluorenyl group.
EXAMPLE 10-1
Copolymerization of Butadiene/Hexene
[0165] A solution composed of 10 ml of toluene, 100 ml of hexene, 42.3 mg of this known complex of the formula [Me 2 Si(Me 3 SiC 5 H 3 ) 2 ]NdCl and 20 molar equivalents relative to the neodymium of the co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10, then 30 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0166] After a reaction time of 28 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 5.0 g. The molecular mass Mn of the copolymer was 5900 g/mol (Ip=2.5). Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0167] hexene=11.6% and butadiene=88.4%, with:
[0168] 1,2-butadiene=5.3% and 1,4-butadiene=94.7%, 94.5% of which was trans-1,4.
[0169] It will be noted that the butadiene/hexene copolymer obtained in Example 4 according to the invention (copolymerization with the organometallic complex according to Example 1) had a much higher molar content of units resulting from hexene (29.8% compared with only 11.6% in this Example 10-1), and that the copolymerization yield relating to this Example 4 (18.9 g) was very much higher than that of this comparative Example 10-1.
EXAMPLE 10-2
Terpolymerization of Ethylene/Butadiene/Hexene
[0170] A solution composed of 10 ml of toluene, 100 ml of hexene, 33 mg of this known complex of the formula [Me 2 Si(Me 3 SiC 5 H 3 ) 2 ]NdCl and 20 molar equivalents relative to the neodymium of co-catalyst consisting of a “BuLi/DiBAH” mixture with neodymium/BuLi/DiBAH=1/10/10, then a quantity of a butadiene/ethylene mixture (containing 20 mol % of butadiene), so as to obtain a total pressure in the reactor of P=4 bar when the temperature T was 80° C. were introduced in succession into the reactor under an argon atmosphere. The internal pressure of the reactor was then maintained at 4 bar.
[0171] After a reaction time of 2 h, polymerization was terminated by cooling and degassing the reactor, then the terpolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 6.4 g. The molecular mass Mn of the terpolymer was 2600 g/mol (Ip=1.5). Analysis of the terpolymer by 13 C and 1 H NMR was as follows (molar contents):
[0172] hexene=0.8%, ethylene=76.0% and butadiene=23.2%, with
[0173] 1,2-butadiene=1.4% and 1,4-butadiene=98.6%, 100.0% of which was trans-1,4.
[0174] It will be noted that the molar content of units resulting from hexene is extremely low, being less than 1%.
COMPARATIVE EXAMPLE 11
Copolymerization of Butadiene/Hexene by Means of Another Known Organometallic Complex and a Co-Catalyst
[0175] The catalytic system used here was one of those described in the above-stated patent specification EP-A-1 092 731 as being usable for the copolymerization of ethylene and butadiene.
[0176] This catalytic system comprises an organometallic complex of the formula [Me 2 Si(C 13 H 8 ) 2 ]NdCl, where Me denotes a methyl group, and a BuLi/DiBAH co-catalyst.
[0177] It will be noted that this organometallic complex comprises two fluorenyl groups, unlike the organometallic complex according to the invention.
[0178] A solution composed of 10 ml of toluene, 100 ml of hexene, 28 mg of this known complex of the formula [Me 2 Si(C 13 H 8 ) 2 ]NdCl and 20 molar equivalents relative to the neodymium of the co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10, then 25 ml of butadiene were introduced in succession into a reactor under an argon atmosphere. The temperature of the polymerization reactor was adjusted to 80° C.
[0179] After a reaction time of 18 h, polymerization was terminated by cooling and degassing the reactor, then the copolymer was obtained by precipitation in methanol. After drying at reduced pressure at 70° C., the yield was 0.5 g. Two fractions of copolymer were obtained (very low yield), one of low molecular mass Mn (1830 g/mol, Ip=1.3) and the other of high molecular mass (91160 g/mol, Ip=1.75). Analysis of the copolymer by 13 C and 1 H NMR was as follows (molar contents):
[0180] hexene=1.8% and butadiene=98.2%, with:
[0181] 1,2-butadiene=12.8% and 1,4-butadiene=87.2%, 68.6% of which was trans-1,4.
[0182] It will be noted that the butadiene/hexene copolymer obtained in Example 4 according to the invention (copolymerization with the organometallic complex according to Example 1) had a much higher molar content of units resulting from hexene (29.8% compared with only 1.8% in this Example 11), and that the copolymerization yield relating to this Example 4 (18.9 g) was very much higher than that of this comparative Example 11.
APPENDIX
[0000] 13 C NMR and 1 H NMR Analyses of the α-olefin and Butadiene Copolymers:
[0183] The instrument used for these analyses was a Bruker DRX 400 spectrometer operating at a frequency of 400 MHz for the proton and 100.6 MHz for the carbon. The analysis solvent was a mixture of deuterated tetrachloroethylene (TCE) and benzene (C 6 D 6 ). The spectra were recorded at a temperature of 90° C.
[0000] 1) Analysis of a Copolymer by 1 H NMR:
[0184] Analysis of a 1 H NMR spectrum of an α-olefin and butadiene copolymer makes it possible to reveal the composition of the copolymer (content of butadiene and α-olefin) and the ratio between 1,2 and 1,4 insertion of the butadiene without distinguishing between 1,4-trans and 1,4-cis insertions.
[0185] The spectra were divided into 5 zones (S 0 −S 4 ) corresponding to characteristic lines of the various protons belonging to the α-olefin (designated OI), to the butadiene inserted as 1,2 (V) or as 1,4 (L) (see Table 1).
[0186] Integration of the different regions defined in Table 1 enabled us very rapidly to discover the total quantity of butadiene (B=L+V) and the 1,2/1,4 ratio:
S 3 =2 V i.e. V=S 3 /2
S 4 =2 L+V i.e. L =( S 4 −S 3 )/2
and therefore:
B=S 3 /4 +S 4 /2 (total quantity of butadiene)
V /( V+L )=( S 3 /2)/( S 3 /4 +S 4 /2) (butadiene content inserted as 1,2)
[0187] Two spectra relating respectively to hexene-butadiene and hexadecene-butadiene copolymers were obtained by 1 H NMR, each of the these two copolymers having been synthesized by means of the organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x prepared in Example 1 and a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10. Table 1 below provides details of the assignment of the lines on these spectra.
TABLE 1 zones (δ (ppm)) (number of protons) assignment S 0 (0.5-1 ppm) 3H (OI) S 1 (1-1.65 ppm) (2n-3)H (OI) + 2H (V) S 2 (1.65-2.65 ppm) 4H (L) + 1H (V) S 3 (4.65-5.06 ppm) 2H (V) S 4 (5.06-6.4 ppm) 2H (L) + 1H (V)
[0188] In order to obtain the total quantity of α-olefin in the copolymer, it is theoretically sufficient to use one of the two zones S 0 or S 1 but various situations may arise.
[0189] First of all, when the molar masses of the copolymers are low, the characteristic lines of saturated (butyl, octyl or isobutyl) chain ends are found in the S 0 −S 1 zone, which means that this zone is no longer characteristic of the α-olefin insertion rate. In this case, the rate will have to be determined on the basis of 13 C NMR of the copolymer.
[0190] In the case of long olefins or when the α-olefin content is not very high, the S 0 line is too weak to be used directly for determining the α-olefin content and the S 1 line or the two lines (S 0 +S 1 ) should be used instead.
[0191] Finally, in some cases, resolution of the S 0 , S 1 and S 2 surface areas is poor, so preventing them from being integrated separately and therefore the α-olefin insertion rate will be determined on the basis of the sum total of these surface areas.
[0192] A distinction must accordingly be drawn between various scenarios. Each calculation is adjusted to some of the above-described circumstances and the results obtained may be confirmed with the different methods:
[0000] 1 st Case: Use of S 0 Alone (Relatively High Molar Masses)
[0193] S 0 =3OI and therefore:
OI=S 0 /3 (quantity of α-olefin)
2 nd Case: Use of S 1 Alone (in the Case of Long Olefins)
[0194] S 1 =(2n-3)OI+2V=(2n-3)OI+S 3 (n number of carbons of the α-olefin)
OI= ( S 1 −S 3 )/(2 n− 3) (quantity of α-olefin)
3 rd Case: Use of (S 0 +S 1 ) because S 0 is not Reliable (Low α-olefin Content or long olefins) or S 0 and S 1 are Poorly Resolved.
[0195] (S 0 +S 1 )=3OI+(2 n-3)OI+S 3 =2nOI+S 3
OI= ( S 0 +S 1 )− S 3 )/2 n (quantity of α-olefin)
4 th Case: Use of (S 1 +S 2 ) because S 1 and S 2 are Poorly Resolved.
[0196] (S 1 +S 2 )=(2 n-3)OI+S 3 +2S 4 −S 3 /2=(2 n-3)OI=OI+2S 4 +S 3 /2
OI= ( S 1 +S 2 )−2 S 4 −S 3 /2)/(2 n− 3) (quantity of α-olefin)
5 th Case: Use of (S 0 +S 1 +S 2 )
[0197] (S 0 +S 1 +S 2 )=2 nOI+S 3 /2+2S 4
OI= (( S 0 +S 1 +S 2 )− S 3 /2−2 S 4 )/2 n (quantity of α-olefin)
[0198] Copolymer composition may readily be deduced on the basis of the quantities of butadiene and α-olefin calculated above.
[0000] 2) Analysis of a Copolymer by 13 C NMR:
[0199] Analysis of the 13 C NMR spectra of the copolymers makes it possible to identify the copolymer's microstructure more precisely. On the basis of this microstructural analysis by NMR (i.e. quantification of the various linkage sequences of the “monomeric” units, namely butadiene diads or triads, specifically 1,2/1,4-cis butadienes and 1,4-trans- and α-olefin), it is possible to reveal the composition of the copolymer and the cis/trans ratio of 1,4 insertion of the butadiene. This analysis is specific to each α-olefin.
[0200] We have decided to provide a detailed description of the analysis of the 13 C NMR spectrum of a hexene-butadiene copolymer by presenting the overall method for assigning the different lines of the spectrum and then quantifying the composition of the copolymer. For all the other α-olefins, the presentation will be briefer, but the procedure used is identical to that for hexene.
[0201] We were also content merely to analyse the aliphatic carbon zone (high field) without paying attention to the alkene carbon zone (low field) because the latter provides no additional information.
[0202] All the copolymers investigated in this section have relatively high molar masses which makes it possible to avoid having a 13 C NMR spectrum which is disrupted by the peaks corresponding to the chain ends.
[0000] 2.1) Hexene-Butadiene Copolymer:
[0203] 13 C NMR was used to obtain the spectrum of a hexene-butadiene copolymer synthesized by means of the organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x prepared in Example 1 and a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10.
[0204] The characteristic lines of a (CH 2 ) carbon are immediately evident at 27.83 (line 4) and 33.10 ppm (line 8) in a position of a butadiene double bond inserted respectively in 1,4-cis and 1,4-trans position in a butadiene-butadiene linkage (as in a polybutadiene). The characteristic lines of a butadiene inserted in 1,2 position in a polybutadiene are also present in a low content at 34.5 and 38.4 ppm.
[0205] On the other hand, the characteristic signals of hexene-hexene linkages are absent (no line at 41.17 ppm (CH 2 ), which is characteristic of an HH linkage in a polyhexene).
[0206] The other unidentified signals must therefore correspond to hexene-butadiene (HB) linkages in which the hexene is isolated (BHB). Analysis of the ethylene-butadiene copolymers obtained with this catalyst thus demonstrates that the butadiene was essentially inserted in 1,4-trans position. We could thus expect to tend to find this type of insertion in the copolymers of butadiene and α-olefins.
[0207] We thus sought out the characteristic lines of a 1,4-trans butadiene/hexene/1,4-trans butadiene (THT) linkage. To this end, we used as the starting point the chemical shifts of an EHE linkage of a hexene-ethylene copolymer to which we applied the increments due to the influence of a trans double bond (T) which were determined in the laboratory for the ethylene-butadiene copolymers:
[0208] (α(trans)=+2.84; β(trans)=0; γ(trans)=−0.5; δ(trans)=−0.15 and ε-trans)=−0.04 ppm).
[0209] This procedure is illustrated by scheme A and Table 2 below. It made it possible to identify eight new signals (lines 1, 2, 5, 6, 9-12 of the spectrum) which are characteristic of the THT linkage (Table 2).
TABLE 2 Calculated and observed chemical shifts of the characteristic lines of a THT linkage. δ (THT) δ (THT) carbon δ (EHE) exp. increment calculated observed Δδ a T 34.48 (a) α + δ 37.17 37.25 +0.08 a′ T 34.48 (a) β + γ 33.98 34.20 +0.22 b′ T 27.30 (b) α + δ 29.99 30.32 +0.33 CH 38.11 (CH) β + γ 37.61 37.89 +0.28 1 14.16 (1) — 14.16 14.11 −0.05 2 23.46 (2) ε 23.42 23.33 −0.09 3 29.54 (3) δ + ε 29.35 29.41 +0.06 4 34.09 (4) δ + γ 33.44 33.61 +0.21
[0210] All the main signals of the spectrum of the hexene-butadiene copolymer have thus been assigned. Two other less intense lines (lines 3 and 7) have also been identified as being specific to a BHB linkage in which the butadiene is inserted in 1,4-cis (C).
[0211] In this case, only carbons a or b′ are affected by a change in the manner of insertion of the butadiene, the others have identical shifts whether the double bond is cis or trans. It is in fact commonly accepted that the increments due to the influence of a cis and trans double bond are identical except for the carbon in a position of the latter.
[0212] The chemical shifts of the carbons adjacent to a cis double bond (C) were obtained on the basis of those determined for THT by deducting the observed difference between a CH 2 in a position of a cis and trans double bond in a polybutadiene (Δδ=5.15 ppm).
[0213] Table 3 below shows all the chemical shifts for the carbons of a hexene-butadiene copolymer (on the basis of the spectrum).
TABLE 3 Chemical shifts of the carbons of a hexene-butadiene copolymer: (see scheme A above for annotation) type diads line no. of carbon affected δ ppm 12 CH(H) (T or C) H 37.89 11 a T H T 37.25 10 a′ C + a′ T (T or C) H 34.20 9 H4 — 33.61 8 α T 2 T (T or C) 33.10 7 a C H C 32.12 6 b′ T T H 30.32 5 H3 — 29.41 4 α C 2 C (T or C) 27.83 3 b′ C C H 25.11 2 H2 — 23.33 1 H1 — 14.11
[0214] The hexene units were quantified by using carbons H3 (line 5), H4 (line 9) or a′ (line 10), the integrals of which are more reliable than the others (H1, H2: not completely relaxed because at end of branching; different CH:NOE . . . ).
[0215] and therefore:
H=A 5 =A 9 =A 10 (or the mean of the three)
[0216] For butadiene, a distinction must be drawn between 1,4-cis (C) and 1,4-trans (T) insertions.
[0217] Taking account of all the carbons in a position of the double bonds results in:
[0218] 2T=2 T(C or T)+TH=2 T(C or T)+{right arrow over (TH)}+{right arrow over (HT)} (carbons in α position of T in the butadiene-butadiene and butadiene-hexene diads),
[0219] 2C=2 C(C or T)+CH=2 C(C or T)+{right arrow over (CH)}+{right arrow over (HC)} (carbons in a position of C).
[0220] After assignment of the lines (see table 3 above), this results in:
[0221] 2 T(C or T)=A 8 , {right arrow over (TH)}+{right arrow over (HT)}=“b′ T +a T ”=A 6 +A 11
[0222] 2 C(C or T)=A 4 , {right arrow over (CH)}+{right arrow over (HC)}=“b′ C +a C ”=A 3 +A 7 and therefore,
2 T=A 8 +A 6 +A 11 and 2 C=A 4 +A 3 +A 7 and 2( T+C )=2 L=A 3 +A 4 +A 6 +A 7 +A 8 +A 11
[0223] We can therefore determine the rate of insertion of hexene in the copolymer together with the stereochemical properties of butadiene insertion:
[0224] hexene content:
[0225] H/(H+L)=2A 10 /(2A 10 +A 3 +A 4 +A 6 +A 7 +A 8 +A 11 ) (L=1,4 butadiene) which must be corrected by taking account of the rate of τ insertion of the butadiene in 1,2 position determined from the 1 H NMR and which becomes:
H/ ( H+B )=2 A 10 /(2 A 10 +(1/(1-□))( A 3 +A 4 +A 6 +A 7 +A 8 +A 11 ))
(= H/ ( H+L+V )= H/ ( H+ (1/(1-τ)) L ))
[0226] 1,4 insertion of butadiene:
cis/cis+trans ratio in the copolymer=( A 4 +A 3 +A 7 )/( A 3 +A 4 +A 6 +A 7 +A 8 +A 11 ))−cis/cis+trans ratio in the butadiene-butadiene diads= A 4 /( A 4 +A 8 )−cis/cis+trans ratio in the butadiene-hexene diads=( A 3 +A 7 )/( A 3 +A 6 +A 7 +A 11 )
Propylene-Butadiene Copolymer:
[0227] 13 C NMR was used to obtain the spectrum of a propylene-butadiene copolymer synthesized by means of the organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ), prepared in Example 1 and a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10.
[0228] We used the same procedure as above to assign the different lines (see Table 4 below). No propylene unit linkage was observed, the propylene units always being isolated between two butadiene units.
[0229] The annotation is shown in scheme B below.
TABLE 4 type diads line no. of carbon δ ppm affected 7 a T 40.29 P T 6 a′ C + a′ T 36.95 (T or C) P absent ac 35.07 P C 5 α T 33.06 2 T (T or C) methine (P) 33.00 (T or C) P (T or C) 4 b′ T 30.45 T P 3 α C 27.80 2 C (T or C) 2 b′ C 25.23 C P 1 P1 19.57 —
[0230]
[0231] On the basis of these assignments, we determined the composition and the microstructure of the copolymer:
[0232] P=A 6 ,
[0233] 2T=2 T(C or T)+TP and 2C=2 C(C or T)+CP
[0234] (TP and CP are non-oriented diads),
[0235] i.e. 2(T+C)=2 T(C or T)+2 C(C or T)+(TP+CP)=(A 5 −A 6 )+A 3 +2A 6 and therefore, the content of propylene is:
[0236] P/(P+L)=2A 6 /(A 3 +A 5 +3A 6 ) (L=1,4 butadiene) which must be corrected by taking account of the rate of τ insertion of the butadiene in 1,2 position determined from the 1 H NMR and which becomes:
P/ ( P+B )=2 A 6 /(2 A 6 +(1/(1-τ))( A 3 +A 5 +A 6 ))
[0237] With regard to butadiene insertion, it is easy to determine:
−cis/cis+trans ratio in the butadiene-butadiene diads= A 3 /( A 3 +A 5 +A 6 )−cis/cis+trans ratio in the butadiene-propylene diads= A 2 /( A 2 +A 4 )
2,3) Butene-Butadiene Copolymer:
[0238] 13 C NMR was used to obtain the spectrum of a butene-butadiene copolymer synthesized by means of the organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x prepared in Example 1 and a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10.
[0239] Assignment of the lines of this spectrum is described in Table 5 below. The butene is practically always isolated between two butadiene units inserted in 1,4-trans position (TBT). The annotation used is identical to that used for the propylene with the exception of carbons B1 and B2 which correspond to the lateral alkyl group.
TABLE 5 type diads line no. of carbon δ ppm affected 9 methine (B) 39.45 (T or C) B (T or C) 8 a T 36.76 B T 7 a′ C + a′ T 33.64 (T or C) B 6 α T 32.96 2 T (T or C) absent a C 31.54 B C 5 b′ T 30.31 T B 4 ? (not assigned) 29.46 ? 3 α C 27.81 2 C (T or C) 2 B2 26.27 — virtually absent b′ C 25.11 C B 1 B1 11.09 —
[0240] On the basis of these assignments, we determined the composition and the microstructure of the copolymer:
[0241] B=A 5 =A 7 =A 8 (or the mean of the three)
[0242] 2T=2 T(C or T)+TB=A 6 +A 5 +A 8 and 2C=2 C(C or T)+CB=A 3 i.e. 2(T+C)=A 3 +A 6 +A 5 +A 8 and therefore, the content of butene is:
[0243] B/(B+L)=2A 7 /(2A 7 +A 3 +A 6 +A 5 +A 8 ) (L=1,4 butadiene) which must be corrected by taking account of the rate of r insertion of the butadiene in 1,2 position determined by 1 H NMR and which becomes:
B/ ( B+Bu )=2 A 7 /(2 A 7 +(1/(1-τ)( A 3 +A 6 +A 5 +A 8 ))
[0244] With regard to butadiene insertion, the following is found:
cis/cis+trans ratio in the butadiene-butadiene diads= A 3 /( A 3 +A 6 )
no 1,4-cis in the butadiene-butene diads
2.4) Octene-Butadiene Copolymer:
[0245] 13 C NMR was used to obtain the spectrum of an octene-butadiene copolymer synthesized by means of said organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ) x prepared in Example 1 and a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10.
[0246] Assignment of the lines of this spectrum is described in table 6 below. The octene is always isolated between two butadiene units inserted in 1,4-trans position (TOT). Scheme C below shows the annotation used.
TABLE 6 type diads line no. of carbon δ ppm affected 8 Methine (O) 37.97 (T or C)O 7 a T 37.26 O T 6 a′ C + a′ T 34.20 (T or C)O 5 O6 34.00 — 4 α T 33.03 2 T (T or C) — O3 32.30 — absent a C 32.13 O C — O4 30.40 — 3 b′ T 30.04 T O 2 α C 27.83 2 C (T or C) 1 O5 27.13 — — absent b′ C 24.79 C O — O2 22.94 — — O1 14.09 —
[0247] The composition and microstructure of the polymer is determined on the basis of these assignments:
[0248] 2O=A 1 +A 5
[0249] 2T=2 T(C or T)+TO=A 4 +A 3 +A 7 and 2C=2 C(C or T)+CO=A 2 i.e. 2(T+C)=A 2 +A 4 +A 3 +A 7 and therefore, the octene content is:
[0250] O/(O+L)=(A 1 +A 5 )/((A 1 +A 5 )+A 2 +A 4 +A 3 +A 7 ) (L=1,4 butadiene) which is corrected by taking account of the rate of r insertion of the butadiene in 1,2 position determined by 1 H NMR and which becomes:
O/ ( O+B )=( A 1 +A 5 )/( A 1 +A 5 )+(1/(1-τ)( A 2 +A 4 +A 3 +A 7 ))
[0251] With regard to butadiene insertion, the following is found:
cis/cis+trans ratio in the butadiene-butadiene diads= A 2 /( A 2 +A 4 )
no 1,4-cis in the butadiene-octene diads
2.5) Hexadecene-Butadiene Copolymer:
[0252] 13 C NMR was used to obtain the spectrum of a hexadecene-butadiene copolymer synthesized by means of said organometallic complex of the formula [Me 2 Si(C 5 H 4 )(C 13 H 8 )]NdCl(OC 4 H 8 ), prepared in Example 1 and a co-catalyst consisting of a “BuLi/DiBAH” mixture, with neodymium/BuLi/DiBAH=1/10/10.
[0253] Assignment of the lines of this spectrum is described in table 7 below.
TABLE 7 type diads line no. of carbon δ ppm affected 8 Methine (H) 38.00 (T or C)H 7 a T 37.26 H T 6 a′ C + a′ T 34.20 (T or C)H 5 H14 34.02 4 α T 33.03 2 T (T or C) — H3 32.25 virtually absent a C 32.13 H C 3 H12 30.44-30.34 — H5-H11 30.04 — b′ T 29.98 T H H4 29.65 — 2 α C 27.83 2 C (T or C) 1 H13 27.20 — absent b′ C 24.79 C H — H2 22.94 — H1 14.09
[0254] As with octene, the hexadecene is always isolated between two butadiene units inserted in 1,4-trans position (THT). On the basis of the various assignments, it may be concluded:
[0255] 2H=A 1 +A 5
[0256] 2T=2 T(C or T)+TH=A 4 +2A 6 and 2C=2 C(C or T)+CH=A 2 i.e. 2(T+C)=A 2 +A 4 +2A 6 and therefore, the hexadecene content is:
[0257] H/(H+L)=(A 1 +A 5 )/((A 1 +A 5 )+A 2 +A 4 +2A 6 ) (L=1,4 butadiene) which must be corrected by taking account of the rate of T insertion of the butadiene in 1,2 position determined by 1 H NMR and which becomes:
H/ ( H+B )=( A 1 +A 5 )/(( A 1 +A 5 )+(1/(1-τ)( A 2 +A 4 +2 A 6 ))
[0258] With regard to butadiene insertion, the following is found:
cis/cis+trans ratio in the butadiene-butadiene diads= A 2 /( A 2 +A 4 )
no 1,4-cis in the butadiene-hexadecene diads
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A catalytic system usable for the copolymerization of at least one conjugated diene and at least one monoolefin, a process for preparing this catalytic system, a process for preparing a copolymer of a conjugated diene and at least one monoolefin using said catalytic system, and said copolymer are described. This catalytic system includes: (i) an organometallic complex represented by the following formula:
{[P(Cp)(Fl)Ln(X)(L x )} p (1)
where Ln represents a lanthanide atom to which is attached a ligand molecule comprising cyclopentadienyl Cp and fluorenyl Fl groups linked to one another by a bridge P of the formula MR 1 R 2 , M is an element from column IVa of Mendeleev's periodic table and R 1 and R 2 each represent alkyl groups of 1 to 20 carbon atoms or cycloalkyl or phenyl groups of 6 to 20 carbon atoms, X represents a halogen atom, L represents an optional complexing molecule, such as an ether, and optionally a substantially less complexing molecule, such as toluene, p is a natural integer greater than or equal to 1 and x is greater than or equal to 0, and (ii) a co-catalyst selected from alkylmagnesiums, alkyllithiums, alkylaluminums, Grignard reagents and mixtures of these constituents.
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RELATED APPLICATIONS
This application claims priority to Taiwan Application Serial No. 096213122, filed on 9 Aug. 2007 and Taiwan Application Serial No. 096216223, filed on 28 Sep. 2007, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a waterproof structure of a respiratory tube, and more particularly, relates to a waterproof structure of a respiratory tube used for snorkeling.
2. Descriptions of the Related Art
Respiratory tubes are essential for snorkeling. Even a beginner who cannot swim can snorkel if he or she knows how to use the respiratory tube. For this reason, manufacturers have continuously improved respiratory tubes to make them more convenient and easier to use.
The most important component of the respiratory tube is its waterproof structure. In a conventional waterproof structure, which is disposed at the end of the respiratory tube, there is a floating ball therein that functions much like an air floating bucket. When the respiratory tube is immersed into water, the floating ball will float upwards and seal the respiratory tube with the aid of a properly designed connecting rod that is connected with the floating ball. Sea water then is prevented from entering, allowing the diver to dive into the sea.
In addition, a conventional respiratory tube having a waterproof valve is disclosed in U.S. Pat. Nos. 7,077,127 and 6,904,910. The waterproof valve of the respiratory tube comprises a soft diaphragm disposed at a top opening of the respiratory tube by a linkage. When a floating device of the respiratory tube is immersed into water, it will drive the linkage to indirectly move the diaphragm against the opening of the respiratory tube thereby preventing water entry. On the contrary, when the floating device of the respiratory tube departs from water, it will drive the linkage to indirectly move the diaphragm apart the opening.
Unfortunately, this conventional waterproof structure requires a complex assembly process and increases the manufacturing cost because of the relatively large number of components. Furthermore, when using the conventional respiratory tube, sometimes the waterproof structure closes prematurely even before the diver dives into the water, or is prone to water entry, thus preventing the respiratory tube from functioning properly.
Therefore, it is important to design a simplified waterproof structure that can function properly at all times without it being too costly.
SUMMARY OF THE INVENTION
One objective of this invention is to provide a waterproof structure of a respiratory tube, which can seal or open the respiratory tube depending on the buoyancy provided by the liquid and the gravity of the waterproof structure itself.
Another objective of this invention is to provide a waterproof structure of the respiratory tube, which can either be formed integrally or by joining individual components together, thus eliminating a complex assembly process as used in the prior art and reducing the manufacturing costs thereof.
Yet a further objective of this invention is to provide a waterproof structure of a respiratory tube, which is designed in such a manner that its own lid will automatically shut without any external driving force, thus improving the waterproof efficacy of the respiratory tube.
To this end, a waterproof structure of a respiratory tube disclosed in this invention comprises a hollow body and a lid. The hollow body comprises two opening ends opposite to each other. The lid is pivoted onto the hollow body at the first opening end and is adapted to rotate about the pivot. When the lid is not immersed into the liquid, a fluid communication will be formed between the two opening ends by gravity. On the contrary, when part of the lid is immersed in the liquid, the lid will close the first opening end of the tube due to the buoyancy provided by the liquid to prevent liquid entry.
The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for the people skilled in this field to well appreciate the features of the claimed invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic perspective view of the components of a conventional waterproof structure;
FIG. 1B is a schematic perspective view of the conventional waterproof structure;
FIG. 2A is a schematic cross-sectional view of the waterproof structure of the present invention when the lid is not immersed in the fluid;
FIG. 2B is a schematic perspective view of the waterproof structure of the present invention when the lid is not immersed in the fluid;
FIG. 3A is a schematic cross-sectional view of the waterproof structure of the present invention when the lid is immersed in the fluid;
FIG. 3B is a schematic perspective view of the waterproof structure of the present invention when the lid is immersed in the fluid; and
FIG. 4 is a schematic cross-sectional view of the waterproof structure when the lid is immersed in the fluid in another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1A and 1B illustrate a conventional respiratory tube having a waterproof structure which mainly comprises a main body 10 and a cover 20 , with a blocking device 30 disposed inside the cover 20 . The main body 10 is shaped into a hollow tube with a hollow opening 14 which may be extended to the opening of the said respiratory tube. A plurality of fasteners 11 , 12 and 13 are provided on the main body 10 for connection with the cover 20 . The cover 20 is shaped like a bowl and has the blocking device 30 therein. The blocking device 30 comprises a directional moving rod 31 disposed through the axial hole of the cover 20 , a cap 32 disposed above the directional moving rod 31 and a floating element 33 hooked below the directional moving rod 31 . When the floating element 33 floats upwards due to the buoyancy provided by the liquid, it will drive the directional moving rod 31 , so that the cap 32 will seal the opening 14 .
FIG. 2B is a schematic perspective view of a waterproof structure 40 in accordance with one preferred embodiment of this invention, while FIG. 2A is a schematic cross-sectional view of the waterproof structure 40 as shown in FIG. 2B . The waterproof structure 40 comprises a hollow body 41 and a lid 50 . The waterproof structure is formed integrally or by assembling major components together. A complex assembly process as used in the prior art is thus eliminated, as well as the high manufacturing costs.
The hollow body 41 has a first opening end 411 and a second opening end 412 opposite to the first opening end 411 . The first opening end 411 is disposed at the upper end of the hollow body 41 to form a fluid communication between the hollow body 41 and the atmosphere. The second opening end 412 is disposed at the lower end of the hollow body 41 for connection with the respiratory tube.
The lid 50 comprises a pivot 51 , a closing surface 52 , an enclosed chamber 53 and a venting aperture 54 . In particular, the pivot 51 of the lid 50 is disposed at the first opening end 411 of the hollow body 41 to allow the lid 50 to rotate about the pivot 51 . In addition, the contour of the closing surface 52 is adapted to match the first opening end 411 , so that it can seal the first opening end 411 of the hollow body 41 to prevent liquid from entering the respiratory tube via the first opening end 411 . In this embodiment, the closing surface 52 is a part of the lid 50 . Alternatively, in another embodiment, the closing surface 52 is adapted to define a sidewall of the enclosed chamber 53 , of which the sidewall faces the first opening end 411 . Those of ordinary skill in the art can change the position of the closing surface 52 , which is not limited herein.
Additionally, the overall density of the enclosed chamber 53 is less than that of the liquid, so when the enclosed chamber 53 is immersed into the liquid, the buoyancy provided by the liquid will drive the lid 50 to rotate about the pivot 51 to seal the first opening end 411 of the hollow body 41 . When the lid 50 is not immersed into the liquid, or when only part of the lid 50 is immersed into the liquid with the lid 50 still separated from the first opening end 411 of the hollow body 41 , the atmospheric air outside the first opening end 411 will ventilate within the hollow body 41 via the venting aperture 54 and further flow into the respiratory tube via the second opening end 412 .
FIGS. 2A and 3A illustrate the properties of the waterproof structure 40 . As the lid 50 of the waterproof structure 40 of this invention is pivoted between the first and second positions, a portion thereof can move along the contour of the hollow body 41 to allow the waterproof structure 40 to function smoothly. In particular, as shown in FIG. 2A , when the lid 50 has not yet been immersed into the liquid, the lid 50 tends to stay at the first position due to its own gravity, so that a fluid connection is formed between the atmosphere and the respiratory tube via the first opening end 411 and second opening end 412 . As a result, the diver can breathe. On the other hand, when the enclosed chamber 53 of the lid 50 is partially immersed in the liquid, the lid 50 is adapted to rotate about the pivot 51 to the second position and stay there due to the buoyancy provided by the liquid to the closed chamber 53 , so that the closing surface 52 seals the first opening end 411 as shown in FIG. 3A .
For example, when the lid 50 of the waterproof structure 40 is immersed in sea water with a density ranging substantially from 1.02 g/cm 3 to 1.07 g/cm 3 , the overall density of the closed chamber 53 of this invention is less than that of the sea water. As a result, the closed chamber 53 will float on the sea water due to the buoyancy, causing the lid 50 to rotate so that the closing surface 52 can seal the first opening end 411 , as shown in FIG. 3B . In contrast, when the lid 50 of the waterproof structure 40 of this invention leaves sea level, the enclosed chamber 53 will, by gravity, drive the closing surface 52 to depart from the first opening end 411 . The atmospheric air will then flow into the two opening ends 411 and 412 of the hollow body 41 of the waterproof structure 40 via the venting aperture 54 . Consequently, ventilation is formed through the respiratory tube, thereby allowing the divers to breathe.
In another preferred embodiment of the invention, the lid 50 of the waterproof structure 40 comprises a floating element 55 , as shown in FIG. 4 . In this embodiment, the material of the floating element 55 has density lower than the liquid. For example, the material of the floating element 55 has density less than 1.02 g/cm 3 when it is used in the sea water. The material of the floating element 55 can be selected from wood, foam or the combination thereof. Those of ordinary skill in the art can use other materials having lower density, which are not limited herein. Besides, the structure of the floating element 55 is not limited to the closed structure, which depends on the design. In this embodiment, the closing surface 52 is a part of the lid 50 . Alternatively, the closing surface 52 is adapted to define the sidewall of the floating element 55 , of which the sidewall faces the first opening end 411 .
When the floating element 55 is partially immersed into the liquid, the buoyancy provided by the liquid will drive the lid 50 to rotate to seal the first opening end 411 thereby preventing liquid entry. When the floating element 55 departs from the liquid, the floating object 50 will, by gravity, drive the closing surface 52 to depart from the first opening end 411 , so that the atmospheric air outside will ventilate within the hollow body 41 of the waterproof structure 40 .
In addition, in the preferred embodiment of this invention, a sealing element 521 may be further disposed at the closing surface 52 of the waterproof structure 40 , as shown in FIG. 2A , so that the closing surface 52 can tightly seal the first opening end 411 . However, this embodiment is only one example, and those of ordinary skill in the art will appreciate that, the sealing element 521 , such as a ring (not shown), may be alternatively disposed at the first opening end 411 to make the closing surface 52 seal the first opening end 411 tightly.
The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.
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A waterproof structure of a respiratory tube is provided. The waterproof structure comprises a hollow body and a lid. The hollow body has a first opening end and a second opening end opposing to the first opening end. The lid pivots onto the hollow body at the first opening end. Before the lid is immersed into liquid, the gravity of the lid can keep the lid at a certain position so that the respiratory tube is well-ventilated. After a part of the lid is immersed into the liquid, the buoyancy provided by the liquid forces the closing surface thereof to substantially seal the first opening end and prevent liquid from going into the tube.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to medical devices and, in particular, to an improved knee brace hinge.
[0003] 2. Description of the Related Art
[0004] Many types of braces have been made available for the support of body joints which have become weakened as a result of sports activity, accident, deterioration due to age, or disease. Braces for the knee are designed primarily to provide support while enabling the knee to function during normal activity.
[0005] Knee braces are often utilized by people who have suffered a knee injury and require some means of protection against further aggravation of the knee during rehabilitation. A knee brace can limit the amount of damage to an injured knee by providing the patient with adequate knee stabilization and control. Stabilization and control is achieved in such a manner as to permit the patient relative freedom in the normal use of the knee joint while, at the same time, permitting control over the joint so as to optimize healing.
[0006] In addition, knee braces are often employed by a person having previously suffered a knee injury who wishes to actively participate in strenuous and demanding physical activity. In such cases where the person seeks knee support in furtherance of activities involving heavy running or sprinting, it is extremely advantageous to design a knee brace which most accurately simulates the true motions of the anatomical knee joint. This will minimize the leg forces required to overcome mismatched motions and generally increase comfort levels.
[0007] Knee braces generally serve two purposes. Firstly, the brace has to support the knee at all times, but especially during movement. Secondly, the brace should limit knee movements in flexion or extension within limits beyond which injury to the knee may occur. Further, movements are confined to the varus/valgus plane.
[0008] Flexion is defined as flexing of the knee from the extended position to a position where the foot and ankle is bent towards the thigh. Extension is defined as being the opposite movement. An extended leg is normally straight with virtually no bending at the knee joint.
[0009] Knee braces for providing support for the knee of a person are well known in the art. Such braces generally include a tibial shell which is constructed so as to be closely configured to the shape of the lower leg and a femoral shell which is constructed so as to be closely configured to the shape of the thigh area of the leg. The two shells are secured to their respective areas on the leg and are interconnected by some type of mechanism so as to pivot relative to each other as the knee is bent. The mechanism is usually a pair of hinge joints, one on each side of the knee brace, with the tibial shell usually being attached to the lower part of each one of the two knee joints and the femoral shell usually being attached to the upper part of each one of the two hinge joints.
[0010] Often, a person will wear knee braces bilaterally. When wearing double upright rigid knee braces bilaterally, the medial hinges often interfere with one another. The hinges sometimes lock together, causing the knee brace wearer to fall or injure himself. This problem is evident during normal walking and running, but becomes pronounced in activities such as snow skiing or motocross.
[0011] Therefore, there is a need for an improved knee brace which prevents interference and/or locking between the medial hinges.
SUMMARY OF THE INVENTION
[0012] The present invention provides an improved knee brace including an upper portion and a lower portion pivotally attached at a hinge, which permits rotation of the upper portion with respect to the lower portion. A plurality of adjustable straps secures the knee brace to the leg. A hinge deflector encases the hinge and prevents locking of opposite medial hinges during bilateral knee brace use.
[0013] The hinge assembly includes a hinge cover, parallel plates and a plurality of fasteners for connecting the plates, cover, and hinge deflector to the knee brace. The hinge deflector comprises a shell having rounded surfaces, which encase the internal components of the medial hinge and also deflects the opposing medial hinge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a perspective view of a knee brace of the present invention.
[0015] [0015]FIG. 2 is a perspective exploded view of a knee brace hinge of the knee brace of FIG. 1.
[0016] [0016]FIG. 3 is a perspective exploded view of a knee brace hinge of the knee brace of FIG. 1.
[0017] [0017]FIG. 4 is a perspective view of a knee brace hinge deflector of the knee brace of FIG. 1.
[0018] [0018]FIG. 5 is a top view of the knee brace hinge deflector of FIG. 4.
[0019] [0019]FIG. 6 is a side view of the knee brace hinge deflector of FIG. 4.
[0020] [0020]FIG. 7 is an end view of the knee brace hinge deflector of FIG. 4.
[0021] [0021]FIG. 8 is a cross-sectional view of the knee brace hinge deflector of FIG. 5 through line 8 - 8 .
[0022] [0022]FIG. 9 is a bottom view of the knee brace hinge deflector of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Knee Brace
[0024] [0024]FIG. 1 shows an orthopedic brace for supporting a joint having a plurality of complaint support components. The knee brace 100 of the present invention includes a hinged shell 105 and a plurality of adjustable support straps 110 engaging the brace at two points on opposite sides of the hinge to stabilize the weakened joint throughout its range of motion. The shell 105 has an upper portion 115 conformable to the thigh and a lower portion 120 conformable to the lower leg. Each of the shell portions 115 , 120 is preferably formed from a single continuous shaped piece of a stiff material such as certain plastics, fiberglass, composites, certain metals, and the like, as are known to those of skill in the art.
[0025] The upper portion 115 includes a cuff 125 , having a lateral arm 130 and a medial arm 135 . The cuff 125 has a preformed arcuate shape sized to snugly conformingly engage the anterior portion of the thigh.
[0026] The lower portion 120 includes a cuff 140 , having a lateral arm 145 and a medial arm 150 extending therefrom. The lower portion 120 has substantially the same structure as the upper portion, but is sized to conform to the lower leg of the user. The lower cuff 140 has substantially the same configuration as the upper cuff 125 , but the preformed arcuate shape thereof is sized somewhat smaller to snugly conformingly engage the calf of the lower leg.
[0027] The upper and lower portions 115 , 120 are connected across rotatable hinges 155 , 160 . More specifically, lateral upper arm 130 is pivotally connected to lateral lower arm 145 and medial upper arm 135 is pivotally connected to medial lower arm 150 across lateral hinge 155 and medial hinge 160 , respectively. A resilient pad 180 may also be provided to cushion the knee joint from the rigid hinges 155 , 160 . (For simplicity, a pad is only shown on the hinge 155 .)
[0028] Medial hinge 160 also preferably includes a hinge deflector 165 for preventing interference between medial hinges when a user is wearing a knee brace on each leg. The hinge deflector 165 acts as a shield to the internal components of the medial hinge 160 and deflects the opposite medial hinge, preventing the hinges from locking together.
[0029] The support straps 110 are preferably adjustable in length, enabling the user to modify the support strap tension, and consequently the degree of support the brace provides to the joint. Support straps 110 are preferably formed from a wear-resistant supple material such as pliant leather, or natural or synthetic cloth, such as nylon and the like. The material should be compliant, but substantially unstretchable.
[0030] Support straps 110 enable closure of brace 100 around the limb on which the brace is mounted. As seen in FIG. 1, each of the cuffs 125 , 140 is held in place by straps, and a strap connector. A separate strap is provided at the upper arms, surrounding the upper leg. A separate strap is provided at the lower arms, surrounding the lower leg. Each strap is integrally provided with a tab and cap fastener assembly 175 at the ends thereof to fix the strap and enable adjustment to the length of the straps 110 for close conformance of the shell 105 to the limb on which the brace is mounted.
[0031] Hinge Assembly
[0032] Referring to FIGS. 2 and 3, an exploded medial hinge assembly 160 and hinge deflector 165 are shown. Lateral hinge assembly 155 is also shown. It will be apparent to one of skill in the art that the hinge assembly 160 and an associated hinge deflector 165 can be incorporated into many other types of conventional hinged orthopedic braces without substantial modification. It is also appreciated that lateral hinge assembly 155 has the same features as medial hinge assembly 160 . Although hinge deflector 165 is intended for use with medial hinge assembly 160 , it is appreciated that hinge deflector 165 may also be used with lateral hinge assembly 155 .
[0033] The hinge assembly 155 , 160 comprises a hinge cover 205 , parallel plates 210 , 215 , an upper rotary connector 220 and a lower rotary connector 225 . Washers 230 may also be provided between parallel plates 210 , 215 and connectors 220 , 225 . The cover 205 and plates 210 , 215 are formed from one or more high-strength, rigid materials, such as metals or plastics. Upper and lower rotary connectors 220 , 225 are respectively formed integrally with the upper and lower cuff arms 130 , 135 and 145 , 150 . The connectors 220 , 225 have semi-circular ends that are pivotally anchored by rivets 235 and are provided with interlocking teeth 240 . This construction of the hinge assembly 155 , 160 enables rotatable engagement of the upper and lower rotary connectors 220 , 225 and correspondingly enables rotation of the upper and lower portions 115 , 120 relative to each other.
[0034] The hinge deflector 165 is secured to the parallel plates 210 , 215 , and connectors 220 , 225 by rivets 235 , or other suitable fasteners, passing through apertures 245 . Hinge cover 205 is secured to the parallel plates 210 , 215 and connectors 220 , 225 by screws 250 , or other suitable fasteners, passing through apertures 255 .
[0035] A hinge extension stop 260 is preferably provided to interface with rotary connectors 220 , 225 at interlocking teeth 240 . Extension stop 260 limits the range of motion of the rotary connectors 220 , 225 and, consequently, brace 100 .
[0036] Hinge Deflector
[0037] The hinge deflector 165 shown in detail in FIGS. 4 - 9 comprises a thin walled shell 400 which is configured to encase the hinge assembly. The shell 400 has a generally elliptical shape as viewed in FIGS. 4 and 5. The shell has an outer or hinge side 415 which faces the hinge, encasing the hinge assembly, and facing away from the knee. The shell also has an inner side 420 which faces the knee, and thus may be referred to as the knee side. As seen in FIGS. 2 and 3, the shell is actually positioned between the knee and the brace hinge, although shell portions extend to the outer side of the hinge.
[0038] The shell outer side 415 includes an outer perimeter surface 422 surrounding a central recess 425 having a generally elliptical shape also. The plate 215 and washer 230 of the hinge assembly fit within the recess 425 .
[0039] The bottom wall of the recess includes a plurality of apertures 430 for attaching the hinge assembly to the knee brace. Two apertures 430 are shown, lying approximately on a longitudinal axis of the recess for attaching the hinge deflector to the knee brace with the fasteners or rivets 235 which pass through the components of the hinge assembly and the knee brace. Two apertures 435 are also shown, lying on an axis generally perpendicular to the longitudinal axis, for securing the stops 260 to the plates 210 and 215 with the screws or fasteners 250 .
[0040] The outer side 415 includes a projection 405 which extends along a majority of the length of one side of the elliptically-shaped shell 400 . This can be referred to as the forward side or edge in that it is the side closest to the forward portion of a person's knee when the brace is in use. The projection includes a straight inner wall 405 a which protrudes from the recess 415 and the surrounding surface 422 , with a portion of that wall being flush with one side of the wall of the recess. The projection includes an outer surface 405 b which slopes toward a peripheral skirt 442 , and an outer edge 441 of the shell 400 , as seen in FIGS. 7 and 8. While the central portion of the projection curves basically toward the edge 441 , as seen in FIG. 7, the projection ends taper or curve to the surface 422 , as seen in FIGS. 4 and 6.
[0041] The outer side 415 also includes a projection 440 extending from surface 422 on the edge of the shell opposite from the projection 405 . That edge of the shell can be referred to as the rear edge since it is closest to the back of the knee when the brace is in use. As seen, the projection 440 is only in the central portion of that edge in that space is needed for the rotational movement of the hinge. The projection 440 limits this movement. The projection 440 also has a straight inner wall 440 a and an outer curved surface 410 , for deflecting external objects. The curve surfaces 405 and 410 curve inward toward the knee brace and hinge assembly when assembled, for deflecting an interfering external object. The curved surfaces 405 and 410 have approximately the same slope; however, different slopes may be employed and the curved surface 405 preferably extends further than the curved surface 410 . The outer skirt 442 of the outer side 415 is also slightly tapered, so that there are no edges for interfering with the hinge. As seen, both projections extend above the surface 422 about the same amount to perform their deflector function.
[0042] The shell inner side 420 preferably includes a plurality of ribs 445 for providing additional strength to the hinge deflector.
[0043] In a preferred embodiment, hinge deflector 165 is a molded plastic material. However, any material having sufficient rigidity to withstand impact forces encountered during impact of hinge assemblies during physical activities are contemplated herein.
[0044] Resilient pad similar to the pad 180 shown on hinge 155 in FIG. 15 is preferably releasably fastened to the shell inner side 420 by conventional releasable fastening means such as a hook and hoop fastener coupling, commonly referred to as VELCRO, wherein one element of the coupling is substantially permanently affixed to the inner side 420 and the other element of the coupling is substantially permanently affixed to resilient pad 180 . The resilient pad may be any knee brace pad, as known to those of skill in the art.
[0045] Referring to FIGS. 2 and 3 as well as the description of the deflector shell, it may be seen that the deflector is positioned on the knee or inner side of the knee brace hinge. The plate 210 and washer 230 fit into the recess in the hinge side of the shell. The hinge side is next placed against the rotary hinge connectors 220 and 225 , with the connectors fitting between the projections 405 and 440 . A washer 230 and the plate 215 covered by the hinge cover 205 are next positioned adjacent the connectors and between the projections 405 and 440 . The upper edges of the projections are about flush with the outer surface of the hinge cover 205 so that interference of that cover with adjacent objects is deflected by the curved surfaces 405 b and 410 . Thus, it can be seen that an entire hinge assembly is substantially encased by the deflector shell.
[0046] The hinge deflector prevents locking and/or interference of a medial hinge with a medial hinge of another knee brace or, alternatively, prevents locking with other external devices, such as components of a motocross bike. The hinge deflector 165 encases the hinge and deflects the external object with curved surfaces 405 , 410 . The curved surfaces 405 , 410 of the hinge deflector 165 prevent the locking because the external object slides along and off the curved surfaces 405 , 410 . The protruding curved surfaces 405 , 410 extend out and over knee brace and hinge assembly to deflect any surfaces or objects that may interfere with knee brace function.
[0047] Although the present invention has been described in terms of certain preferred embodiments, other embodiments of the invention including variations in dimensions, configuration and materials will be apparent to those of skill in the art in view of the disclosure herein. In addition, all features discussed in connection with any one embodiment herein can be readily adapted for use in other embodiments herein. The use of different terms or reference numerals for similar features in different embodiments does not imply differences other than those which may be expressly set forth. Accordingly, the present invention is intended to be described solely by reference to the appended claims, and not limited to the preferred embodiments disclosed herein.
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A knee brace hinge deflector is provided for preventing interference and/or locking of the medial hinges of bilateral knee braces. The hinge deflector includes a shell having rounded surfaces for encasing a first medial hinge assembly and deflecting a second medial hinge assembly of bilaterally worn knee braces.
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This application is a divisional of U.S. patent application Ser. No. 10/379,373 filed on Mar. 4, 2003, now U.S. Pat. No. 6,827,515.
FIELD OF THE INVENTION
This invention relates to a stacker for a printer and, in particular, to a stacker for paper tickets, vouchers and the like that exit a transaction-based printer. The invention is particularly useful, e.g., in connection with gaming and lottery printers that provide racetrack tickets, lottery tickets or the like.
BACKGROUND OF THE INVENTION
High speed printers, such as inkjet, thermal, dye sublimation and dot matrix printers are used to provide vouchers, coupons, tickets, receipts and the like to consumers. For example, when a winning lottery prize becomes relatively large, the lines at ticket sales counters become long. In addition, the number of tickets purchased by each person in the line can be relatively large. Heretofore, most point of sales (POS) and other transaction-based printers have been designed to issue one ticket, voucher, coupon or receipt at a time. Sales personnel are therefore required to remove each printed sheet manually from the printer. When a number of lottery or wagering tickets, for example, are purchased in a single transaction, the sales person must compile all of the tickets for that transaction by hand. This can be a time consuming procedure leading to errors being made and long delays in ticket sales.
It would be advantageous to provide an automatic stacking function for printers used in such environments. Such a stacking function would be particularly advantageous for high speed printers that dispense quantities of tickets, vouchers, receipts, coupons and other printed substrates. Such printers are often used in wagering and lottery terminals, as well as in other point of sale terminals such as those used to print train tickets, bus tickets, movie and theater tickets, retail coupons, and other substrates of value.
The present invention provides an automated stacker for a printer having the aforementioned and other advantages.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to improve transaction-based printers, such as POS printers, ticket printers, and the like. It is a further object to provide a gaming and lottery printer that will help speed the sale of tickets.
It is a still further object of the present invention to reduce the amount of manual handling required to produce a series of tickets, vouchers, coupons or other printed substrates purchased under one sale transaction.
Another object of the present invention is to provide an automatic stacker for a small transaction-based printer that does not increase the size of the printer.
These and other objects of the present invention are attained by a transaction-based printer that has a first drive for advancing a sheet through the printer in a first direction. A kicker element is adapted to contact the sheet after printing. A second drive is operatively associated with the kicker element for advancing the sheet in a second direction opposite the first direction. An output bin is provided for collecting the sheet when it is advanced in the second direction.
In another embodiment, a sheet drive is provided for advancing sheet material from a spool through a printing station and then registering the sheet in a stationary condition within a cutting station. A cutter, such as a rotary cutter, is mounted within the cutting station. The cutter can include, for example, a stationary blade and a movable blade for severing the registered sheet from the spool. A kicker element (e.g., a kicker wheel) is mounted upon a shaft within the cutting station. A clutch allows the kicker element to freely rotate in one direction as the sheet is forwarded into the cutting station. A drive system that is associated with the cutter control mechanism reverses the direction of rotation of the kicker element once the cutting operation is completed, locking the clutch and thus causing the severed sheet to be kicked into a collecting bin.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the present invention, reference will be made to the following detailed description of the invention which is to be read in association with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a point of sale printer showing the printer cover slightly raised;
FIG. 2 is a left perspective view of the printer shown in FIG. 1 with the bottom part of the printer housing being removed to further show the cutter and kicker element drive system;
FIG. 3 is a right perspective view of the printer similar to that shown in FIG. 2 further showing the sheet feed drive system;
FIG. 4 is a partial perspective view of the printer main frame with parts broken away to better illustrate the cutting station of the printer; and
FIG. 5 is a partial sectional view taken through the drive roller of the sheet feed drive.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the drawings, there is illustrated a printer, generally referenced 10 , that embodies the teachings of the present invention. It is noted that the illustrated printer is only one example embodiment of a printer that can incorporate the features of the present invention.
The printer 10 includes a rectangular shaped housing 12 upon which a hinged cover 13 is provided. The hinge is located at the back of the housing cover so that the cover can swing upwardly and rearwardly to provide ready access to a paper bin located in the rear of the printer housing. The bin is configured to accept a supply spool of paper 15 , which serves as the substrate for printing a ticket, voucher, coupon or the like. A main feed roller 17 is rotatably mounted in the cover and contains a gear 18 that is affixed to one end of feed roller shaft 19 . The feed roller gear 18 is arranged to mesh with an intermediate or idler gear 20 when the cover is closed. The idler gear 20 forms part of the main drive system of the printer and is coupled to the main drive gear 23 by means of a second idler gear 24 . The drive gear 23 is mounted upon the output shaft 25 of a drive motor that is housed within the control section 27 of the printer.
The present printer as herein described is a thermal printer, however, as should become apparent from the disclosure below, the present invention is applicable for use in any type of gaming, lottery, POS, or other transaction-based printer that is known and used in the art. For a thermal printer implementation, the paper on the supply spool is fabricated of a heat sensitive (i.e., thermal) material. The end of the spool first is threaded through a printing station 29 as illustrated in FIG. 5 and is held tightly against a thermal printing head 30 by the feed roller 17 when the cover is moved to a closed position. Sufficient friction is provided between the printing head and the feed roller to advance the paper through the printing station, where a desired image is applied to the paper based on an input from the printer control section 27 using well known thermal printing techniques.
The imaged substrate is advanced by the feed roller into the cutting station 35 ( FIG. 4 ) where the paper is registered and the feed roll drive is deactivated as the printed ticket, voucher, coupon or the like is severed from the supply spool. A rotary cutter is located in the cutting station. The cutter includes a stationary upper blade 40 and a coacting rotatable lower blade 41 (FIG. 4 ). The paper is guided into the cutting station between the two blades and as will be described in greater detail below, and is cut from the spool by rotating the movable blade past the fixed blade. It should be appreciated that the particular type of cutter is not critical, and other types of cutters can be substituted for the rotary cutter described herein. Alternatively, precut paper stock can be used, in which case no cutter is required in the printer.
The operation of the cutter in the illustrated embodiment is independently controlled through a separate cutter drive system best illustrated in FIG. 2 and generally referenced 43 . The cutter drive system includes its own cutter drive motor 46 mounted upon the main frame 47 of the printer. The shaft 44 of the cutter drive motor passes through the side wall 48 of the frame and has a drive pinion 45 secured thereto. The drive pinion is coupled to a drive wheel 50 ( FIG. 4 ) by a pair of idler gears 51 and 52 that are arranged to turn the drive wheel at a desired speed. A pin 53 is mounted upon the outer face of the wheel and protrudes outwardly from the wheel face.
As illustrated in FIGS. 2 and 4 , a rocker arm 55 is secured to one end of the rotatable cutter blade 41 by means of a mounting hub 56 . The arm contains an elongated slot 57 in which the drive wheel pin rides. An optical sensor 58 is mounted within a housing adjacent to the drive wheel. A tab or flag 59 is carried by the drive wheel and is adapted to pass through a slit in the sensor housing to generate an output signal to the controller indicating when the rotatable blade has reached the end of cut position. At this time, the direction of rotation of the cutter motor is reversed and the rotatable cutter blade is returned to the home or start of cut position.
A gear segment 60 is carried upon the mounting hub of the rocker arm. The gear segment mates with an idler gear 62 which in turn mates with a drive gear 63 affixed to one end of a kicker roll shaft 65 that is journaled for rotation in the upper part of the printer main frame 47 . A kicker roll 67 is carried upon the kicker roll shaft and is coupled to the shaft by a one way clutch 69 . Paper that is forwarded into the cutting station will pass through a nip created between the kicker roll and a backing plate 70 that is carried by the cover. The nip is formed when the cover is brought to a fully closed position. The clutch is arranged to permit the kicker roll to rotate freely upon the kicker roll shaft when the paper is forwarded from the printing station into the cutting station and as the movable blade is moved from its home position to the end of cut position.
Upon the return stroke of the rotatable cutter blade, the rotation of the kicker roll shaft is reversed and the clutch now locks the kicker wheel to the shaft. Accordingly, the severed paper ticket, voucher, coupon or the like (the “cut sheet”) is driven by the kicker wheel through the discharge opening 75 in the cover back toward a collecting bin 77 located in the top of the cover. A sheet guide is positioned at the entrance to the bin that directs the cut sheet into the bin. The bottom wall 80 of the bin ( FIG. 1 ) is inclined downwardly and serves to direct the sheets entering the bin downwardly so that the lower portion of each sheet is captured under the top half wall 83 of the bin.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by those skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.
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A transaction-based printer has a sheet drive for forwarding a sheet through a printing station to a cutting station where the sheet is severed from a spool by a rotary cutter. A kicker element is mounted in the cutting station. Movement of the kicker element is coordinated through the cutter drive with that of the rotary cutter so that the severed sheet is kicked into a bin located in the top cover of the printer. The printer can be, for example, an ink-jet, dot matrix, dye sublimation or thermal printer used to print tickets, vouchers, coupons or the like.
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RELATED APPLICATIONS
This application is a Continuation-in-part of application Ser. No. 08/562,772 filed Nov. 27, 1995, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a rapid immunoassay kit and method for semi-quantitatively detecting antibodies in human saliva to antigens of disease-related microorganisms, e.g., antibodies to Mycobacterium tuberculosis . This invention also encompasses an alternative embodiment that permits quantitative, though less rapid, detection of antibodies in saliva by adapting the methodology of the semi-quantitative immunoassay to an enzyme linked immunosorbant assay (ELISA). Within this invention, this alternative embodiment is referred to as the quantitative immunoassay, or similar, to distinguish it from the rapid, semi-quantitative immunoassay.
2. Description of the Prior Art
Though not substantially related to the invention described herein, there have been several efforts of peripheral interest. Ebersole has described a SEROLOGICAL METHOD FOR THE IDENTIFICATION OF MICROORGANISMS in U.S. Pat. No. 4,458,014 for the identification of diseases of the mouth. Chen et al. have described in U.S. Pat. No. 4,866,167 a DETECTION OF HUMAN ORAL CELLS BY NUCLEIC ACID HYBRIDIZATION to detect oral bacterial species. The methods of both Ebersole and Chen et al. are technically complex, time consuming, not rapid and are not based on detecting antibodies in saliva to antigens of disease-related microorganisms.
Olson et al. have described an IMMUNOLOGICAL COLOR CHANGE TEST INVOLVING TWO DIFFERENTLY COLORED REAGENT SPOTS in U.S. Pat. No. 4,639,419. Their patent describes a substantially different methodology than that described herein. This test is an agglutination reaction directed toward identifying antigenic material wherein a colored substrate and colored reagent combine, in positive reactions, to give the appearance of a third color.
Higerd and Goust have described an IMMUNOSUPPRESSIVE EXTRACELLULAR PRODUCT FROM ORAL BACTERIA in U.S. Pat. No. 4,268,434. Their patent relates to a method of producing an extracellular immunosuppressive bacterial material from various bacteria to suppress the natural immunity in patients where this outcome is desired, e.g., organ transplant patients. This procedure has substantially different objectives and methodology than the invention described herein.
Antibodies are naturally produced biomolecules which react specifically with usually foreign biomolecules called antigens. Disease-related microbial infections, e.g., Mycobacterium tuberculosis which causes tuberculosis, are usually characterized by the production of antibodies to the specific antigens of disease-related microorganisms. Antibodies are also produced with other diseases and afflictions, e.g., autoimmune diseases where there is an often destructive antibody response to the host—not necessarily related to a microbial antigen. In the case of autoimmune diseases, the host usually supplies the antigens of disease-related microorganisms. Within this invention, the term “disease-related antigens” includes microbial antigens and other substances capable of possessing antigenic properties and which are associated with specific diseases, conditions and disorders, including infectious diseases and autoimmune diseases. Antibodies are expressed in saliva; their detection in saliva is fundamental and unique to this invention.
This invention, as an example, can determine individuals actively or previously infected with Mycobacterium tuberculosis and thus aid in the diagnosis of tuberculosis. Mycobacterium tuberculosis causes tuberculosis (1-4) and this is widely acknowledged throughout the medical community. There are several screening tests for tuberculosis. The Mantoux test uses tuberculin purified protein derivative (PPD) which is injected intracutaneously (e.g., Tubersol®, Connaught Laboratories Limited, Willowdale, Ontario, Canada) (1). A delayed hypersensitivity reaction develops in individuals having previous infection with Mycobacterium tuberculosis . The injection site is normally read within 48 to 72 hours after intracutaneous injection of the antigen; a palpable induration measuring 10 mm in diameter or more is considered a positive reaction. This procedure is accepted as an aid in the diagnosis of tuberculosis infection.
The Heaf test uses a multiple puncture disk which introduces needles through concentrated Old Tuberculin applied to the skin (1). The tine test uses tuberculin adhering to metal tines; inoculation is accomplished by simple pressure into the skin (1). The Heaf and tine tests are acceptable for screening but should be confirmed by the Mantoux test (1). Antigenic material can also be applied by scratch, i.e., Pirquet's test (2). Similar to the Mantoux test, these tests generally require 48 to 72 hours after inoculation before results can be determined. The Bacillus of Caimette and Guerin (BCG) is a live, attenuated strain of Mycobacterium bovis which has been used with varying success as a vaccine against tuberculosis in countries where the prevalence of tuberculosis is high (5). Mycobacterium bovis is not normally found in humans, but since it shares antigens present in Mycobacterium tuberculosis , it can serve as an antigen source to detect host antibodies to Mycobacterium tuberculosis . BCG causes tuberculin conversion to positive; it has also been used to stimulate the immune system against a variety of medical conditions. In this invention, both PPD and BCG can serve as suitable antigens to detect host antibodies to desired mycobacteria.
Other antigens have been described. Maes has described A60-ANTIGEN FROM MYCOBACTERIA AND USE THEREOF AS TUBERCULIN VACCINE in U.S. Pat. No. 4,965,192. This patent describes the A60-antigen as effective for detecting prior exposure of an individual to mycobacterial infections through the use of a cutaneous test. This patent is similar to other inoculation tests mentioned earlier except that a new antigen is used and 24 to 48 hours are required to observe the responses at the test site.
Mycobacterium tuberculosis whole cells (inactivated), lipoarabinomannan of Mycobacterium tuberculosis (6-8) and other mycobacterial derivatives can serve as antigen sources to detect host antibodies to mycobacteria in this invention.
To continue with the Mycobacterium tuberculosis example of this invention, a major advantage is that tuberculosis screening can be done rapidly—in approximately 5 minutes—in one visit and in a non-invasive manner. The advantages of this invention are significant when compared with earlier tests that are invasive, take 48 to 72 hours to obtain results and require two visits of the subject, e.g., the Mantoux and other tuberculosis screening tests. These earlier tests are considered too slow and are invasive. Similar limitations apply to other medical screening and diagnostic tests that are not rapid, invasive (e.g., require blood or serum samples) or involve culturing or other complicated and expensive laboratory procedures. The premise of this use of the assay is that individuals infected with Mycobacterium tuberculosis develop antibodies to this bacterial species which are present in their saliva and which react with mycobacterial antigens. The antibodies are then labeled and color development detected and read visually after addition of an appropriate enzymatic substrate, if required. Color development signifies positive individuals and permits semi-quantitative assessment of antibody levels. Active or previous infection with Mycobacterium tuberculosis is, therefore, determined. This assay aids in the diagnosis of tuberculosis and is rapid, non-invasive, uncomplicated and inexpensive. Less rapid but quantitative simultaneous assessment of multiple (or single) saliva samples is accomplished by adapting the semi-quantitative assay to an ELISA.
What is needed is a rapid, simple, non-invasive assay to semi-quantitatively detect antibodies in saliva to antigens of disease-related microorganisms, e.g., antibodies to Mycobacterium tuberculosis that react with mycobacterial antigens. This assay uses human saliva, is non-invasive, can be developed and read in less than an hour, preferably in about 5 minutes, and is technically simple to operate. A rapid immunoassay to semi-quantitatively detect antibodies in saliva to antigens of disease-related microorganisms, is unique and has never been reported.
What is also needed is an immunoassay capable of quantitatively assessing multiple saliva samples simultaneously. A quantitative immunoassay is needed in instances where specific quantitative measurements or the ability to assess multiple samples simultaneously are desired over the need for a more rapid, semi-quantitative assessment. The adaptation of the rapid, semi-quantitative assay to an ELISA to quantitatively assess a single saliva sample or multiple saliva samples simultaneously is unique and has never been reported.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is an immunodiagnostic assay kit and method to rapidly and semi-quantitatively detect antibodies in saliva produced as part of an immunological response to specific, antigens of disease-related microorganisms, i.e., a host antibody response.
An additional object of this invention is a device for conducting the rapid and semi-quantitative inmmunoassay.
A further object of this invention is the adaptation of the rapid immunoassay to an ELISA permitting simultaneous, quantitative detection of antibodies in multiple (or single) saliva samples produced as part of an immunological response to specific disease-related antigens, i.e., a host antibody response.
These and additional objects of the invention are accomplished by an immunoassay kit and method for rapidly and semi-quantitatively detecting antibodies in saliva to antigens of disease-related microorganisms, and by adaptation of the rapid, semi-quantitative immunoassay to an ELISA thereby permitting quantitative assessment of a single saliva sample or simultaneous quantitative assessment of multiple saliva samples. With this invention, the semi-quantitative assay can be performed on an aliquot of a saliva sample. The semi-quantitative assessment can then be extended by using the quantitative assay to assess a different aliquot of the same saliva sample.
Antigens of disease-related microorganisms are immobilized on a solid substrate and contacted with a saliva sample from the human subject being tested. The saliva samples are filtered with a sample filter or treated with some other separating device such as a centrifuge prior to their contact with the immobilized antigens. Antibodies to the antigens may be present in the saliva sample. These primary antibodies, if present, bind to the immobilized antigens. After blocking, the primary antibodies are then contacted typically with secondary antibodies specific for the primary antibodies having a label or indicator capable of being detected, e.g., alkaline phosphatase. Secondary antibodies can be anti-human IgG, IgA, IgM, alone or in combination. After the addition of an appropriate enzymatic substrate, if required, the label develops identifying the presence of the antibodies whereby active or previous infection with the antigen, e.g., Mycobacterium tuberculosis , is determined. The device for conducting the semi-quantitative assay is a frame or support which holds a solid substrate capable of immobilizing the antigens of interest while permitting drainage of other materials or fluids away from the bound antigens. The device for the quantitative assay includes an ELISA plate reader, 96-well plates, a plate washer, a multidrop dispenser, and related ELISA equipment. The 96-well plates, or similar, are capable of immobilizing the desired antigens of disease-related microorganisms thereby allowing the fundamental immunologic reaction of the semi-quantitative assay to take place in the wells of the plates and measured quantitatively with the ELISA plate reader. For the quantitative assay, each well of the 96-well plates serves as a solid substrate capable of immobilizing the desired antigens of disease-related microorganisms.
BRIEF DESCRIPTION OF THE DRAWING
A more complete appreciation of the invention will be readily obtained by reference to the following Description of the Preferred Embodiments and the accompanying drawing. A more complete appreciation of the invention will be readily obtained by reference to the following Description of the Preferred Embodiments and the accompanying drawings. The representation in each of the figures is diagrammatic and no attempt is made to indicate actual scales or precise ratios. Proportional relationships are shown as approximations.
FIG. 1 is an embodiment of the device for the rapid, semi-quantitative assay and illustrates a positive reaction and the presence of antibodies in human saliva to mycobacterial antigens, thereby normally reflecting active or previous infection with Mycobacterium tuberculosis.
FIG. 2 is an embodiment of the device for the rapid, semi-quantitative assay and illustrates a negative reaction and the absence of antibodies in human saliva to mycobacterial antigens, thereby normally reflecting no active or previous infection with Mycobacterium tuberculosis.
The less rapid, quantitative assay uses conventional ELISA equipment and materials and cannot, therefore, be suitably rendered in a figure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The lack of rapid, accurate, non-invasive diagnostic screening methods for many medical conditions unnecessarily increases subject risk, contributes to inefficiency, and often increases costs. For example, tuberculosis continues to pose a serious health problem worldwide and screening personnel for tuberculosis is routinely included in most immunization programs and physical examinations. This invention allows rapid, one-visit identification of subjects actively or previously infected with Mycobacterium tuberculosis , the bacterial species responsible for tuberculosis, by semi-quantitative assessment of Mycobacterium tuberculosis antibodies in saliva samples from the subjects. Within this invention, the terms “infected” and “infection” refer to exposure (active or previous) to an infectious.microorganism (in this example, Mycobacterium tuberculosis ) sufficient to elicit a detectable host antibody response to the microorganism. This invention also allows identification of similarly infected subjects through a quantitative, tho ugh less rapid, assessment of antibodies in saliva by adapting the methodology of the semi-quantitative immunoassay to an ELISA. The quantitative immunoassay thereby permits simultaneous quantitative detection of antibodies to Mycobacterium tuberculosis in saliva samples of multiple (or single) subjects.
The invention is a new and unique approach to aid in diagnostic screening. The invention is directed to immunodiagnostic assays to detect antibodies in saliva to antigens of disease-related microorganisms. For example the presence of certain levels of antibodies to Mycobacterium tuberculosis in saliva normally indicates active or previous infection with Mycobacterium tuberculosis . With the semi-quantitative assay, the invention is intended for one-visit screening applications to aid in the diagnosis of tuberculosis and is a significant improvement over earlier methods which require 48 to 72 hours and a follow-up visit to obtain results. With its adaptation to an ELISA, the invention can simultaneously assess multiple saliva samples of subjects and provide quantitative measurements of the desired antibodies in about 6 to 8 hours which is considerably faster than earlier methods.
This rapid assay kit and method are designed to detect semi-quantitatively the presence of antibodies to antigens of disease-related microorganisms in human saliva, e.g., antibodies to Mycobacterium tuberculosis that react with certain mycobacterial antigens. The assay is fully developed and readable in under an hour, usually about 5 minutes, from the time the subject's saliva sample is contacted with the solid substrate. In a preferred commercial embodiment, the antigens are immobilized on the solid substrate in advance. Within this invention, the terms “rapid assay” and “rapid immunoassay” mean an assay or test that can be developed in under an hour, preferably in less than one-half hour. Most preferably, this rapid assay is fully readable in approximately 5 minutes from the application of the subject's saliva sample to the solid substrate. The kit and method are technically easy to use.
In general, a preferred embodiment of the invention is a clinical diagnostic kit and method designed to rapidly detect the presence of antibodies in saliva that are specific to a disease. For example, the assay uses mycobacterial antigens, e.g., tuberculin BCG antigens, that react with and allow semi-quantitative detection of antibodies to Mycobacterium tuberculosis that may be present in saliva. The kit and method first comprise immobilizing the desired, antigens on the solid substrate and pre-blocking the remainder of the solid substrate; in a preferred commercial embodiment, antigen immobilization and pre-blocking are done in advance. A stimulated saliva sample suspected of containing antibodies to the antigens of disease-related microorganisms is then obtained from the subject being tested. The stimulated saliva sample can be gathered by any of the known techniques for gathering stimulated saliva samples. Saliva is stimulated by chewing paraffin, sugarless chewing gum, or similar. Saliva samples are typically filtered with a sample filter (Whatman part no. AV125UGMF, autovial disposable syringeless filter glass microfiber, 0.45 μm; from Fisher, catalog no. 09-919) to remove undesired particulate matter. Alternatively, samples are treated with some other suitable separating device, e.g., samples can be centrifuged in a high-speed microcentrifuge for 5 minutes (or more). Saliva samples are then normally diluted 1:1 with physiologic saline. An aliquot of the diluted saliva sample is placed on a solid substrate, preferably a flow-through filter type device (e.g., Devaron, Inc., Dayton, N.J., 0.45 μm or 0.60 μm) or a device such as described by Oprandy in U.S. Pat. No. 5,039,493 or some other antigen-immobilizing device. The antibodies in the saliva, if present, react with the antigens of disease-related microorganisms. The solid substrate is then blocked and washed. The solid substrate can be any of the commonly used solid substrates such as nitrocellulose filter media, any of the materials described by Oprandy or some other antigen-immobilizing device. Once the antigens are imimobilized on the solid substrate, the solid substrate is contacted with the saliva sample containing, if positive, antibodies that are specific for the immobilized antigens (e.g., antibodies in saliva to Mycobacterium tuberculosis that react with the immobilized mycobacterial antigens). The antibodies are then contacted with a label capable of being detected, thereby identifying the presence of the antibodies. Any detectable label or indicator can be used such as an enzyme (e.g., alkaline phosphatase; peroxidase; galactosidase; etc.) which reacts with an appropriate enzymatic substrate to yield an insoluble end product. Labels such as colloidal gold coupled to protein-A, protein-G, or some other protein can also be used. Other suitable detectable labels include fluorescent markers, radionuclides, latex particles and others. Once labeled, the amount of desired antibodies in the sample can be semi-quantified by detecting the relative strength of the color development produced by the labeling process. Also, the use of colloidal gold or other labels such as enzymes or fluorochromes can be attached to several probes such as protein-A, protein-G, goat anti-rabbit IgG, goat anti-mouse IgG, and others.
A principal alternative embodiment adapts key elements of the rapid immunoassay to an ELISA for quantitative assessment of a single saliva sample or simultaneous quantitative assessment of multiple saliva samples. This embodiment is normally a laboratory procedure requiring ELISA laboratory equipment and materials and, therefore, is not considered rapid as the term is used herein. This embodiment, though less rapid, has the advantage of quantitative measurements as opposed to the semi-quantitative assessment of saliva samples using the rapid immunoassay. This quantitative assay typically takes about 6 to 8 hours for a fully developed quantitative reading which is, nevertheless, considerably faster than commercially available alternatives taking 48 to 72 hours. The quantitative assay can also be used to extend the assessment of the semi-quantitative assay by using different aliquots of the same saliva sample in both assays.
A further alternative embodiment applies the unique basis of this invention, i.e., detecting antibodies in saliva to antigens of disease-related microorganisms, to all diseases that are associated with detectable host antibodies to antigens of disease-related microorganisms, i.e., any disease, condition or disorder having a detectable host antibody response.
Having described the invention, the following two examples are given to illustrate specific applications of the invention for detecting subjects actively or previously infected with organisms causative of tuberculosis, including the best.mode now known to perform the invention. Example 1 describes the semi-quantitative immunoassay for rapidly detecting antibodies in saliva to Mycobacterium tuberculosis . Example 2 describes the less rapid, quantitative immunoassay for simultaneously detecting antibodies to Mycobacterium tuberculosis in multiple (or single) saliva samples. These specific examples are not intended to limit the scope of the invention described in this application.
EXAMPLE 1
A rapid immunoassay to semi-quantitatively detect antibodies to mycobacterial antigens, normally Mycobacterium tuberculosis in humans, is described in 10 simple and rapid steps:
1. A Bacillus of Calmette and Guerin (BCG) antigen preparation is made with an ampule of BCG Vaccine U.S.P. (FSN 6505-01-337-3126, Organon Technika Corp., Durham, N.C.). The ampule is broken and the contents rehydrated with 0.5 ml of carbonate coating buffer, pH 9.6. The ampule contains 1-8×10 8 colony forming units (cfu) of the BCG antigen, 50 mg per 0.5 ml (or 100 mg per ml). The ampule contents are heat inactivated at 56° C. for 1 hour. The contents are then diluted 1:1 with a solution of MonoPure Elution Buffer (catalog no. 1851520, lot no. 870127087, Pierce Chemical Co., Rockford, Ill.) with 1% Tween-20 (no. 170-6531, Bio-Rad Labs) mixed 1:1 with 2 M sodium acetate buffer, pH 8.0. The mixture is centrifuged in a high-speed microcentrifuge (10,000 rpm Eppendorf) for 5 minutes, the supernatant removed, and the antigen pellet rehydrated with 1 ml of phosphate-buffered saline (PBS). After suitable pre-blocking (see step 2), 1.5 μl of the BCG antigen preparation are then spotted onto a solid substrate, i.e., a flow-through filter device (Devaron, Dayton, N.J., 0.45 em). The carbonate coating buffer, pH 9.6, is prepared as follows:
Coating Buffer, pH 9.6, 1 L
Ultrapure Water
1000
ml
Na 2 CO 3
1.59
g
NaHCO 3
2.93
g
NaN 3
0.2
g
An alternative antigen source uses tuberculin purified protein derivative (PPD) (FSN 6505-00-105-0102, Tubersol®, Connaught Laboratories Ltd., Willowdale, Ontario, Canada). One vial of this PPD source (labeled as 5 ml, actually 8 ml) is dialyzed against deionized water for 1.25 hours, then dialyzed against tris buffered saline, pH 9.55, for 2 hours in 3,500 molecular weight dialysis tubing. The final volume is 9.5 ml. The solution is next freeze-dried and rehydrated with 800 μl of carbonate coating buffer, pH 9.6 (10×Dialyzed PPD). Similar to above, 1.5 μl are then spotted onto a flow-through filter device (Devaron, Dayton, N.J., 0.45 μm) that has not been pre-blocked. Two other alternate antigen sources are Mycobacterium tuberculosis whole cells (inactivated) and Mycobacterium lipoarabinomannan.
2. Nonspecific binding to the solid substrate filter surface is reduced by adding 4 drops (160 μl) of 0.05% gelatin (catalog no. G-8, 275 Bloom; lot no. 734286, Type A purified grade CAS reg. 9000-70-8, Fisher Scientific Co.) plus 0.05% skim milk, dehydrated (Difco, no. 0032-01, control no. 704524) in PBS. It is heated to 56° C. overnight, about 18 hours. One (1) liter of PBS, pH 7.4, is prepared as follows:
PBS, pH 7.4, 1 L
Ultrapure Water 1000 ml
NaCl
8.0 g
KH 2 PO 4
0.2 g
Na 2 HPO 4 .12H 2 O
2.9 g
KCl
0.2 g
NaN 3 (Sodium Azide)
0.2 g
3. The solid substrate filter surface is then washed with one drop (50 μl) of the solution outlined in step 2 to which 0.05% Tween-20. (no. 170-6531, Bio-Rad Labs) has been added to a concentration of 0.5 ml/L.
4. A sugarless chewing gum or paraffin-stimulated saliva sample from a human subject is filtered through a sample filter (Whatman part no. AV125UGMF, autovial disposable syringeless filter glass microfiber, 0.45 μm; from Fisher, catalog no. 09-919). Alternatively, some other suitable separating device is used, e.g., samples can be centrifuged in a high-speed microcentrifuge for 5 minutes. Accepted safety and infection control practices should be followed when working with subject samples, including wearing gloves and safety glasses. Three (3) drops (120 μl) of the saliva filtrate are then mixed 1:1 with 3 drops (120 μl) of sterile 0.85% NaCl by shaking for 10 seconds. Two (2) drops (80 μl) of this mixture are then added to the filter surface of the flow-through filter device (i.e., the solid substrate filter surface) equivalent to 1 drop, 40 μl, of undiluted saliva.
5. The solid substrate filter surface is washed again as in step 3.
6. One (1) drop of 10% normal goat serum (catalog no. 200-6210AG, control no. 34N1903, Gibco, Grand Island, N.Y.) in PBS is then added to the solid substrate filter surface. The serum is earlier heated at 56° C. for 1 hour prior to its dilution with PBS.
7. A detecting antibody solution is prepared using goat anti-human IgG heavy and light chains, alkaline phosphatase labeled antibody conjugate (KPL catalog no. 075-1006, Kirkegaard & Perry Laboratories, Inc., Gaithersburg, Md.). Alternatively, anti-human IgG, IgA, IgM, alone or in combination, can be utilized. The antibody conjugate is supplied as a powder which is rehydrated in 1 ml deionized water, then diluted 1:8 with 0.85% NaCl, then diluted 1:1 with Stabilzyme AP (catalog no. SA01-0125, lot no. SA01401, BSI Corp. Eden Prairie, Minn.). The antibody solution is, therefore, a 1:16 final dilution, and 1 drop (50 μl) is added to the solid substrate filter surface.
8. The solid substrate filter surface is washed again as in step 3.
9. Four (4) drops (200 μl) of BCIP/NBT alkaline phosphatase substrate (5-bromo-4-chloro-3-indoxyl phosphate/p-nitroblue tetrazolium system)(catalog no. ES006-500 ml, Chemicon International Inc.) to which 0.5 mg of Levamisole/ml (catalog no. L-9756; Sigma Chemical Co., St. Louis, Mo.) has been added are next added to the solid substrate filter surface for color development.
10. Two (2) drops (100 μl) of a 1:1 vol:vol mixture of 0.2 M ethylenediaminetetraacetic acid (EDTA) (no. 4653, J. T. Baker Chemical Co., Phillipsburg, N.J.) with tris buffered saline, pH 2.8, (final pH=5.17; final EDTA=0.1 M) are added to the solid substrate filter surface to arrest color development. Semi-quantitative levels of desired antibodies are determined visually by reading and comparing the intensity of the color development against a standard color intensity scale (or chart). The scale is developed in advance by performing the semi-quantitative assay on known concentrations of known antibodies.
The semi-quantitative assay is usually completed in about 5 minutes from the time that the saliva sample is contacted with the filter surface of the solid substrate. In a preferred commercial embodiment, the antigen immobilization and related blocking steps are done in advance. The color changes that develop reflect semi-quantitatively the levels of salivary. antibodies to mycobacterial antigens, i.e., normally Mycobacterium tuberculosis , as shown in FIG. 1 .
The assay does not have to be conducted in the particular order between immobilizing the antigens of disease-related microorganisms and detecting the antibodies. In a preferred commercial embodiment, the antigens of disease-related microorganisms are immobilized in advance on a solid substrate, preferably nitrocellulose media which is part of a flow-through filter device or similar. The solid substrate filter surface is then pre-blocked. The device is then packaged until needed, preferably with the materials, reagent and instructions necessary to perform the assay. When needed, the device is removed from the packaging and a suspected antibody-containing sample, e.g., human saliva, is contacted with the pre-blocked, antigen-containing, solid substrate filter surface. The solid substrate surface is then blocked and washed. An antibody label or indicator which reacts with the antibodies is then applied. When the label is alkaline phosphatase antibody solution, as prepared in step 7 of Example 1, with a BCIP/NBT enzymatic substrate system, a color will develop as shown in FIG. 1 for samples positive for certain levels of antibodies in saliva to mycobacterial antigens, normally Mycobacterium tuberculosis in humans. Typically, color changes are read and compared against a standard color intensity scale (or chart) thereby determining semi-quantitative levels of the desired antibodies.
EXAMPLE 2
An inmunoassay to quantitatively detect antibodies in saliva to mycobacterial antigens, normally Mycobacterium tuberculosis in humans, is described in 14 simple steps:
1. A sugarless chewing gum or paraffin-stimulated saliva sample is gathered from a human subject. With this quantitative assay, samples from multiple subjects can be assessed simultaneously. Each sample is filtered through a sample filter (Whatman part no. AV125UGMF, autovial disposable syringeless filter glass microfiber, 0.45 μm; from Fisher, catalog no. 09-919). Alternatively, samples are treated with some other suitable separating device, e.g., samples can be centrifuged in a high-speed microcentrifuge for 5 minutes (or more). The quantitative assay can also be used to extend the assessment of the semi-quantitative assay (an example of the semi-quantitative assay is described earlier in Example 1) by using different aliquots of the same saliva sample in both assays. Accepted safety and infection control practices should be followed when working with subject samples, including wearing gloves and safety glasses.
2. A BCG antigen preparation is made with an ampule of BCG Vaccine U.S.P. (FSN 6505-01-337-3126, Organon Technika Corp., Durham, N.C.). The ampule is broken and the contents rehydrated with 0.5 ml sterile saline (0.85%). The ampule contains 1-8×10 8 cfu of the BCG antigen, 50 mg per 0.5 ml (or 100 mg per ml). The contents are heat inactivated at 56° C. for 1 hour. The contents are then diluted 1:1 with a solution of MonoPure Elution Buffer (catalog no. 1851520, lot no. 870127087, Pierce Chemical Co., Rockford, Ill.) with 1% Tween-20 (no. 170-6531, Bio-Rad Labs) mixed 1:1 with 2 M sodium acetate buffer, pH 8.0. The mixture is centrifuged in a high-speed microcentrifuge (10,000 rpm Eppendorf) for 10 minutes, the supernatant removed, and the antigen pellet rehydrated with 1 ml of PBS (with sodium azide). This yields 1-8×10 8 cfu/ml. The rehydrated antigen pellet is mixed-by shaking vigorously. The mixed antigen pellet is then diluted 1:10 (1:20; 1:40; 1:80) in coating buffer (1X) and 100 μl of diluted antigen preparation is pipetted into each well of 96-well plates. In this example of the quantitative assay, each well of the 96-well plates serves as a solid substrate immobilizing the desired antigens. Alternate antigen sources are PPD, Mycobacterium tuberculosis whole cells (inactivated) and Mycobacterium lipoarabinomannan
3. The well plates are centrifuged for 15 minutes at 2,000 rpm.
4. The fluid is aspirated from the plate wells using Plate Washer EL404 and 100 μl of 0.5% glutaraldehyde-PBS (0.1 ml of 50% glutaraldehyde per 10 ml of PBS) is added to each well. The plates are incubated at room temperature for 15 minutes.
5. The plates are washed 3 times with wash solution. Two hundred (200) μl of blocking solution is added to each well. The plates are then incubated at room temperature for 30 minutes.
6. The plates are washed 3 μtimes with wash-solution.
7. The saliva samples are diluted 1:2 to 1:16 with sterile 0.85% NaCl. One hundred (100) μl of filtered and diluted saliva are added to each well and allowed to incubate for 1 hour at 37° C.
8. The plates are washed 3 times with wash solution.
9. One hundred (100) μl of 10% normal goat serum in PBS (with azide) is added to, each well. The wells are aspirated after 10 minutes.
10. A detecting antibody solution is prepared using goat anti-human IgG heavy and light chains, alkaline phosphatase labeled antibody conjugate (KPL catalog no. 075-1006, Kirkegaard & Perry Laboratories, Inc., Gaithersburg, Md.). Alternatively, anti-human.IgG, IgA, IgM, alone or in combination, can be utilized. The antibody conjugate is supplied as a powder which is rehydrated in 1 ml deionized water, then diluted 1:8 with 0.85% NaCl. One hundred (100) μl of the antibody solution is added to each well. The wells are diluted 1:500 in (1:1 vol:vol) PBS:Stabilzyme AP (catalog no. SA01-0125, lot no. SA01401, BSI Corp. Eden Prairie, Minn.). The plates are then incubated for 1 hour at 37° C.
11. The plates are washed 3 times with wash solution followed by 3 times with distilled water.
12. Two hundred (200) μl of alkaline phosphatase substrate (p-nitrophenyl phosphate, disodium, Smg/tablet dissolved 5 mg/5 ml in 10% diethanolamine) are added to each well. The plates are incubated for 15 to 45 minutes in the dark at room temperature, and read at 15, 30, and 45 minutes or until sufficient yellow color appears. This alkaline phosphatase substrate reagent can be prepared using the formula for the diethanolamine in reagent instructions and nitrophenyl phosphate tablets (Sigma Chemical Co., St. Louis, Mo.) or by using a commercial kit (KPL catalog no. 508000, Kirkegaard & Perry Laboratories, Inc, Gaithersburg, Md.). The color intensity that develops in each well reflects the relative levels of desired antibodies detected.
13. The reaction is stopped using 2N NaOH at 50 μl per well.
14. Antibody levels are quantified by absorbance readings of the color changes obtained by reading the plates at 405 nm using the CERES UV900C Plate Reader. There are separate operating instructions for the Bio-Tek Instruments CERES UV900C Plate Reader, Bio-Tek Instruments EL 404 Microplate Auto Washer and Lab Systems Multidrop Dispenser. The readings normally reflect quantitative levels of antibodies to Mycobacterium tuberculosis in each saliva sample assayed.
Formulas for reagents include:
PBS-0.25-BSA/Tween-20 Wash Solution, 1 L
PBS
1000
ml
Bovine Serum Albumin (BSA)
2.5
g
Tween-20
0.5
ml
Coating Buffer, pH 9.6, 1 L
Ultrapure Water
1000
ml
Na 2 CO 3
1.59
g
NaHCO 3
2.93
g
NaN 3
0.2
g
Glutaraldehyde 0.5%
0.1 ml of 50% solution per 10 ml of PBS
Blocking Solution, 250 ml
PBS
250
ml
BSA
2.5
g
Gelatin
0.25
g
Glycine
1.875
g
Skim Milk
0.125
g
0.5% BSA-1% Goat Serum PBS, 100 ml
BSA
0.5
g
PBS
100
ml
Goat Serum
1
ml
The quantitative assay is usually completed in about 6 to 8 hours. The quantitative assay does not have to be conducted in the particular order between gathering the saliva sample and reading the plates to determine quantitative levels of the desired antibodies.
ADVANTAGES AND NEW FEATURES
A major advantage of this invention is that a semi-quantitative assay of disease-related antibodies in saliva (to Mycobacterium tuberculosis for example) can be performed and read in about 5 minutes compared typically to 2 days or longer for conventional screening. The use of saliva for the source of antibodies is also unique. This semi-quantitative assay is sensitive, specific, non-invasive and can be used in a medical treatment office or similar facility with results obtained while the subject waits. This assay saves an enormous amount of money given the cost savings associated with a subject not having to return days later to determine or receive test results. Subjects do not have to return to have a PPD test read saving the costs of the follow-up visit. In addition, in some scenarios, such as testing refugees, follow-up visits are difficult, unpredictable and not easily controlled. Costs for laboratory analysis, where applicable, can also be avoided or greatly minimized. The semi-quantitative assay also eliminates the need for use and disposal of needles for blood and serum samples and eliminates adverse reactions to intentionally-injected antigens as in the Mantoux test. The inventors are not aware of any other similar inventions or products available on the market.
A second major advantage is that the method can be adapted, when desired over a more rapid semi-quantitative assessment, to an ELISA thereby providing simultaneous quantitative assays of multiple (or single if desired) saliva samples. Like the semi-quantitative assay, the quantitative assay is non-invasive and also eliminates the need for use and disposal of needles for blood and serum samples and eliminates adverse reactions to intentionally-injected antigens as in the Mantoux test. The quantitative assay, though less rapid than the semi-quantitative assay, is, nevertheless, faster than commercially available tests requiring 48 to 72 hours such as the PPD. The inventors are unaware of any similar quantitative assay that measures salivary antibodies to disease-related antigens.
PUBLICATIONS
1. Holvey, David N. and Talbott, John H. (eds.). The Merck Manual of Diagnosis and Therapy . Rahway, N.J.: Merck Sharp & Dohme Research Laboratories, 12th ed., 1972, pp. 136, 141-142.
2. Berkow, Robert and Fletcher, Andrew J. (eds.). The Merck Manual of Diagnosis and Therapy . Rahway, N.J.: Merck Sharp & Dohme Research Laboratories, 15th ed., 1987, pp. 113-116.
3. Isselbacher, Kurt J., Braunwald, Eugene, Wilson, Jean D., Martin, Joseph B., Fauci, Anthony S. and Kasper, Dennis L. Harrison's Principles of Internal Medicine . New York, NY: McGraw-Hill, Inc., vol. 1, 13th ed., 1994, pp. 710-718.
4. Schroeder, Steven A., Tiernery, Jr. Lawrence M., McPhee, Stephen J., Papadakis, Maxine, A. and Krupp, Marcus A. Current Medical Diagnosis & Treatment . Norwalk, Conn.: Appleton & Lange, 1992, pp. 207-213.
5. Baron, Ellen J., Chang, Robert S., Howard, Dexter H., Miller, James N. and Turner, Jerrold A. Medical Microbiology . A Short Course. New York, N.Y.: Wiley-Liss, Inc., 1994, pp. 415-416.
6. Chattedjee, D., Hunter, S. W., McNeil, M. and Brennen, P. J. Lipoarabinomannan. Multiglycosylated form of the mycobacterial mannosylphosphatidylinositols. J. Biol. Chem. 1992; 267(9):6228-33.
7. Chatterjee, D., Lowell, K., Rivoire, B., McNeil, MR. and Brennen, P. J. Lipoarabinomannan of Mycobacterium tuberculosis . Capping with mannosyl residues in some strains. J. Biol. Chem. 1992; 267(9):6234-39.
8. Khoo, K. H., Douglas, E., Azadi, P., Inamine, J. M. et al. Truncated structural variants of lipoarabinomannan in ethambutol drug-resistant strains of Mycobacterium smegmatis . Inhibition of arabinan biosynthesis by ethambutol. J. Biol. Chem. 1996; 271(45):28682-90.
Obviously, many modifications and variations of the present invention are possible in light of the above teaching. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. The principles described above can be readily modified or adapted for various applications without departing from the generic coricept, and, therefore, such adaptations and modifications are intended to be comprehended within the meaning and range of equivalents of the enclosed embodiments. It is to be understood that the terminology and phraseology herein are for the purpose of description and not of limitation.
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A rapid, non-invasive, semi-quantitative immunoassay of saliva has been developed to aid in the diagnosis of diseases, e.g., using saliva to detect subjects actively or previously infected with Mycobacterium tuberculosis , a causative organism of tuberculosis. The semi-quantitative assay comprises spotting disease-related antigens on the surface of a solid substrate; contacting the solid substrate with a saliva sample which, in positive subjects, contains primary antibodies to the disease-related antigens; contacting the primary antibodies with a label capable of being detected; and detecting and reading the label whereby exposure to the antigens is determined. The device for conducting these assays is a frame or support which holds a solid substrate capable of immobilizing the antigens of interest while permitting drainage of other materials or fluids away from the immobilized antigens. A less rapid, quantitative assay has also been developed by adapting the rapid, semi-quantitative assay to an enzyme linked immunosorbant assay thereby providing a quantitative assay capable of assessing multiple saliva samples simultaneously.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This utility application claims the priority dated benefit of U.S. provisional application 61/730,515 filed on Nov. 28, 2012.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
No Applicable.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
Not Applicable.
BACKGROUND
Placing unfinished knitting or live knit stitches onto a device that will securely hold the live stitches without raveling typically requires a stitch holder to hold these stitches safely. Raveling stitches causes unnecessary time loss such as using extra time fixing the area or having to restart the entire project. There are many reasons for someone to set aside live stitches such as when finishing a different section of a garment, finishing a provisional seam when the person is unsure which edging they may wish to use, trying on a garment for fit, temporarily holding unfinished edges together, or needing to start a different project with knitting needles already being used.
A person cannot try on a garment for a precise fit using current stitch holders given the limited sizes when using a cable from an interchangeable needle set because the lengths are predetermined and cannot be adjusted. Furthermore, the current stitch holders distort the knitted item where it folds over on itself, bunches up unnaturally on itself, forces the item to be held straight or flat, or crowds the live stitches. Furthermore still, the current stitch holders unnecessarily change the shape of the knitted item because the knitted material is forced to conform to the material in or the shape of the stitch holder.
SUMMARY
The described embodiment is a locking fastener configured to accept and clamp a string where the string is a collector of a knitted product. The knitted product, for example, is a live or active knit stitches that are to be knitted at a later time.
An assembly for the locking fastener includes an outer element with a groove (e.g., “U”-shaped groove), an inner element that fits into the groove of the outer element, and a spring mechanism that couples the inner element to the groove. Furthermore, the outer element has a peripheral traverse slot penetrating through walls of the groove while the inner element has a slit, which is a through hole in the periphery of the inner element.
When the inner element moves towards the groove, the movement compresses the spring mechanism while it aligns the slit to the peripheral traverse slot. This aligning or overlapping between the slit and the peripheral traverse slot provides a passageway for the string to be fitted into the locking fastener. For example, the passageway forms a channel that is defined by alignment of the peripheral traverse slot and the slit. The slit forms as a middle of the channel. In this example, the channel is capable of fitting an end of the string and allows the string to pass through a hole that is created by the passageway.
A subsequent releasing of the spring mechanism from compression will then allow the inner element to move away from the groove. For example, the spring mechanism pushes the inner element towards an open front-section of the “U”-shaped groove. In this example, the inner element will pull the string through the slit and presses the string against an inside diameter of the peripheral traverse slot on the walls of the outer element. Thus, the inner element clamps the string against the outer element and thereby preventing it from slipping from the locking fastener.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an adjustable stitch holder assembly.
FIG. 2 is a front view of a locking fastener in open position.
FIG. 3 shows, from the front, the locking fastener in the resting or closed position.
FIG. 4 is a diagram of how to place stitches onto the adjustable stitch holder.
FIG. 5 displays an angled top view of how to adjust the stitch holder using the locking fastener.
FIG. 6 exhibits an adaptation of the adjustable stitch holder for flat knitted pieces.
FIG. 7 demonstrates another adaptation of the adjustable stitch holder for knitted items with larger circumferences.
FIG. 8 illustrates a head on view of how to remove stitches from the adjustable stitch holder.
DETAILED DESCRIPTION
FIG. 1 shows an adjustable stitch holder assembly 10 that includes a locking fastener 11 , a string 12 , a hole 14 , a desired length 15 , and a string end 16 . Furthermore, the locking fastener 11 has an inner element 7 , an outer element 8 , and a spring mechanism 9 . As shown, the stitch holder assembly 10 may hold active or live stitches 18 . The active or live stitches 18 may be of a loop-shaped or line-shaped knitted product 17 .
As an example of present implementations herein, the locking fastener 11 can have one or more holes 14 to secure the string 12 . For example, the hole 14 is a hollow space or opening that traverses from one side of the locking fastener 11 to its opposite side. In this example, the hole 14 is a through hole with a circumference that is equal to or larger than the circumference of the string 12 . In another example, the hole 14 has a smaller diameter than the diameter of the string 12 ; however, this requires squeezing of the string 12 in order to facilitate its entry through the hole 14 .
As shown, a first hole 14 - 1 accepts the string end 16 and the string 12 freely extends through the first hole 14 - 1 until the desired length 15 is obtained at one side of the locking fastener 11 . At this stage, the first hole 14 - 1 clamps the string 12 and prevents the string 12 from slipping away from the first hole 14 - 1 of the locking fastener 11 .
A second hole 14 - 2 may then accept the string end 16 and create an adjustable loop-shaped string for holding the knitted product. For example, the second hole 14 - 2 accepts the string 12 and the string 12 freely extends through the second hole 14 - 2 until a desired size of the loop-shaped string is obtained. Upon obtaining the desired size of the loop-shaped string, the second hole 14 - 2 clamps the string 12 and prevents the string end 16 from slipping away from second hole 14 - 2 of the locking fastener 11 .
With continuing reference to FIG. 1 , the outer element 8 has a groove such as, for example, a “U”-shaped groove that may include an open front-section at top portion, and a closed rear-section at a bottom portion. Connecting the open front-section and the closed rear-section is a wall of the groove. For example, the wall may be cylindrical in shape for a cylindrical-shaped locking fastener 11 with cylindrical U-shaped groove or it may include two parallel sides of a rectangular U-shaped groove of a rectangular-shaped locking fastener 11 .
The outer element 8 has a peripheral traverse slot that penetrates the walls of the groove. For example, in the U-shaped groove, the peripheral traverse slot is a space or a through hole that traverses one side of the wall and crosses to the other wall. In this example, the peripheral traverse slot crosses or passes through the space of the groove.
On the other hand, the inner element 7 has a slit that is also a through hole that traverses the body of the inner element 7 . The slit may be of the same size and shape as that of the peripheral traverse slot of the outer element 8 .
As an example of present implementations herein, the inner element 7 is partially disposed into the groove of the outer element 8 . This position allows up and down movement of the inner element 7 to the groove of the outer element 8 . Furthermore, the spring mechanism 9 that couples the partially disposed inner element 7 to the bottom portion of the groove allows the slit to align with the peripheral traverse slot.
For example, pushing the inner element 7 towards the direction of the groove compresses the spring mechanism 9 . This movement provides overlapping of the peripheral traverse slot with the slit. The overlapping creates and increases a passageway in the hole 14 . The passageway, for example, is a channel that is defined by alignment of the peripheral traverse slot and the slit. This alignment—in which the slit forms as a middle of the channel—may accept the string 12 to pass through the locking fastener 11 .
A perfectly aligned peripheral traverse slot and slit may provide a maximum circumference or maximum diameter for the hole 14 . In contrast, releasing the spring mechanism 9 from its compressed state to a resting position will move the slit into tangential position with the peripheral traverse slot. This tangential position, if there is no string 12 in the hole 14 , provides no passageway or a zero diameter of the hole 14 . Furthermore, the inner element 7 through its slit may clamp the string 12 against the outer circle element 8 when the slit is moving towards the tangential position.
The spring mechanism 9 , at the resting position, pushes the inner element 7 away from the groove. The outer element 8 may include a stopper mechanism (not shown) that limits a maximum reach of the inner element 7 when moving up and down into the groove. For example, the stopper mechanism limits a maximum downward movement of the inner element 7 to a certain diameter of the hole 14 . In this example, the stopper mechanism may allow a maximum diameter or a half-opened maximum passageway of the hole 14 .
In another example, the stopper mechanism may limit the resting position of the spring mechanism 9 to a point where the inner element 7 is about to slip from the groove of the outer element 8 . In this example, the resting position limits the spring mechanism 9 from extending beyond the tangential position as described above.
FIG. 2 shows an open hole 13 in the locking fastener 11 . For example, the inner element 7 moves towards the groove of the outer element 8 . This movement towards the groove causes the peripheral traverse slot and the slit to overlap one another. In this example, the overlapping creates the open hole 13 . Releasing the spring mechanism 9 from its resting position by un-squeezing the inner element 7 may clamp the string 12 against the outer element 8 . Thus, the locking fastener 11 firmly secures the string 12 from slipping from the hole 14 as shown in FIG. 3 .
As shown, the locking fastener 11 can be of various types (e.g., cord lock, stopper, fastener, bean lock, or toggle used to adjust jacket drawstrings or secure laundry bags) while the string 12 may be made of a flexible cord such as a leather, polyester, thick thread, elastic, rope, twine, cording, yarn, cotton, rattail, rayon, etc. Furthermore, the locking fastener 11 may be of various shapes (e.g. barrel, bean, round, ball, rectangle, etc.) that is spring-loaded or manually activated.
As an example of present implementations herein, the locking fastener 11 and particularly, the outer element 8 , has a surface perimeter that is greater than the surface of the knitted product to avoid inadvertent slipping of the stitches 18 from the string 12 . The smallest common knitting needle size is “0” or 2 mm, so the string 12 weight recommended for common knitting would be less than 2 mm to accommodate a smaller knit stitch 18 . However, the string weight is limited by the hole 14 size of the locking fastener 11 and the size of the knitting needle needed for the project. Selecting a string 12 color should consider the best contrast to the color of the knit item (e.g. white is seen better against black yarn and black is seen better against white yarn).
FIG. 4 shows the elements for adding stitches 18 to the stitch holder. To start adding the stitches 18 to the stitch holder 10 , the hole 14 accepts one end 21 of the string 12 and the hole 14 clamps the end 21 to stop the stitches 29 from slipping off. The string 12 may pass through the hole 14 without an aid of another device or it can be inserted by pulling the string 12 through a device 19 (e.g. tapestry or sewing needle with a hole) that holds the end 21 through an opening 20 while being pushed through the hole 13 . Once the end 21 is secured in the locking fastener 11 , the unsecured end 16 a needs to be threaded through a device 19 with an opening 20 .
Once the string 12 is threaded, the device 19 slips through the live stitch 18 transferring the stitch 18 from the knitting needle 22 to the string 12 that holds the stitch 29 . This process is repeated until the desired stitches 18 are transferred to the string 12 . Once all the stitches 18 are place on the string 12 , becoming stitch 29 , the locking fastener 11 is opened, the unsecured end 16 a threaded through the device 19 is pushed through the unused open hole 24 , the locking fastener 11 is released, and the device 19 is removed from the string 12 end 16 b . This process secures the stitches 29 to be knited later. The design allows for multiple knit pieces to be secured to one stitch holder 10 requiring fewer knitting notions to transport or store with the convenience of all pieces of a project or multiple projects held securely together. Since items can be removed or added to both ends, this provides better control of how the items are ordered on the stitch holder 10 .
FIG. 5 illustrates how the string 12 can be adjusted to different sizes. For example, the locking fastener 11 can be configured to facilitate any length or loop circumference needed for desired project based on the length of the string 12 . To adjust the length of the string 12 needed for an item, simply open and slide in the direction of the arrows the locking fastener 11 to the desired size or length leaving enough desired length 15 of the string ends 16 for the locking fastener 11 to secure. This length 15 should be long enough so that if the string 12 is accidently pulled hard, then the chance that the ends will slip out of the locking fastener 11 is significantly reduced.
FIG. 6 illustrates how to use the stitch holder assembly 10 for flat knit pieces or as a straight line stitch holder. Secure one string end 17 with a locking fastener 30 , pick up stitches as demonstrated in FIG. 4 and use a second locking fastener 11 to secure the string end 16 . This variation allows flat knit pieces to stay flat and not be forced into a circular shape. Using FIG. 6 instructions, two finished pieces of knit material can be basted together using the string 12 and two fasteners 11 to determine if the pieces will fit together as desired. Another variation is to use two or more locking fasteners 11 and two or more lengths of string 12 .
In FIG. 7 , the first string 27 is secured through an open hole 14 on fastener one 25 . The live stitches 18 are placed on the string 27 , and the unsecured end is secured with the second fastener 26 . Once this is complete, the process is repeated with the second string 28 creating a larger circumference holder. This variation can use multiple locking fasteners and strings.
FIG. 8 illustrates the removal of the live stitches 18 from the stitch holder assembly 10 to be placed on the working knitting needle 22 . Open the locking fastener 11 and pull the needed end 16 of the string 12 through the hole 14 and release the locking fastener 11 to lock in the other end 21 of the string 12 . Push the working knitting needle 22 through each live stitch 18 keeping the string 12 in place until all desired stitches 18 are replaced to the working knitting needle 22 . If there are remaining stitches 18 on the string 12 needed for later, replace the string end 16 back through the hole 14 to secure for a later time. Once the stitch holder 10 is no longer needed (e.g. all the stitches 18 have been transferred to the knitting needle 22 ), slide the string 12 out of the stitches 18 , in the direction of the arrow, that have been placed on the working knitting needle 22 . Then secure one end 21 of the string 12 with the locking fastener 11 and store.
An alternative is to keep the string 12 with the end 16 secured in the hole 14 with the stitches 18 remaining on the string 12 while knitting to track pattern progress or stitch count (e.g. starting row, lace repeats, patterned, cabled, or charted knitting, etc.). Since the materials are small locking fasteners 11 and string 12 that is flexible three of these stitch holders can fit into a small knitting notions case (e.g. Altoids gum tin) alongside other knitting notions (e.g. locking and regular stitch markers and tapestry needle) making these stitch holders 10 easier to transport and store thus more efficient.
While the foregoing written description of the embodiment enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The described embodiment should therefore not be limited by the above described method, and examples, but by all embodiments and methods within the scope and spirit of the invention.
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The adjustable stitch holder is a versatile and easy method for securely holding live stitches when knitting. The stitch holder allows for using smaller materials, a locking fastener and string, that are portable and take little storage room. Adjusting the locking fastener to a specific measurement allows an item to be tried on, to be measured properly, or to determine if the shape is correct. Because the string has little to no memory, the ends, regardless of length, will hang not pulling or distorting the knit material. In addition, the flexible string allows an item to be laid flat for measuring making the measurement more accurate. Further, stitches or knitted items have little chance of being damaged by the stitch holder and the stitch holder will conform to the knit item instead of being forced into a shape.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national stage application of PCT/JP2011/060002 filed on Apr. 19, 2011, and claims priority to, and incorporates by reference, Japanese Patent Applications No. 2010-112614 filed on Apr. 23, 2010, No. 2010-117760 filed on May 6, 2010, No. 2010-158278 filed on Jun. 25, 2010, No. 2010-158279 filed on Jun. 25, 2010, and No 2010-158280 filed on Jun. 25, 2010.
TECHNICAL FIELD
The present invention relates to a navigation device to be used for mobile objects.
BACKGROUND
Due to restriction on safety issues, etc., the object of reaching a target point has not been attained in the conventional art.
SUMMARY
Object to be Attained by the Invention
An object is to improve a capability of reaching a target point while ensuring safety.
Means to Attain the Object
A path reaching to a target point is displayed as an end line 1 , a path reaching to the end line 1 as an end line 2 and a path reaching to an end line ‘n’ as an end line ‘n+1’ sequentially.
Each end line is displayed ingeniously so as to enhance the effect.
Effect of the Invention
A function of reaching a target point is improved without impairing safety.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an example of displaying in the present invention.
FIG. 2 is a block diagram that illustrates an example navigation device for presenting the display of FIG. 1 .
MODE FOR CARRYING OUT THE INVENTION
While eliminating the danger resulting from map display and navigation, a path reaching to a target point and a path reaching to that path are displayed sequentially and the line display is changed in accordance with the moving surround.
DETAILED DESCRIPTION
Below, an embodiment of the present invention will be explained based on the attached drawing. In FIG. 1 , reference number 1 indicates an end line 1 , reference numbers 2 a and 2 b indicate end line 2 , reference number 3 indicates an end line 3 , reference number 4 indicates an end line 4 , and reference number 6 indicates a target point. As shown in FIG. 2 for navigation device 200 , an input unit 201 comprises a means for receiving information on travel, such as a current position, target and mobile object; a memory unit 205 comprises a means for storing data relating to the travel, and a program and process, etc. necessary for operation; a CPU 202 comprises a means for performing processing for necessary searching, calculation, outputting and displaying; and an output unit 203 comprises a means for outputting and displaying information with sounds and images. A display unit 204 comprises a means for displaying sounds and images.
A locator detects a current position from satellite radio waves, a sensor or beacon, etc. In an example of using a portable device, a communication function is provided for transmitting with a center.
Data and a program, etc. necessary for the center may be provided and they can be also transmitted to the portable device via communication after performing necessary processing.
Information on the target is obtained from the Internet, magazines, brochures, tour guides and other variety of means and methods, input and set.
When information on the target, mobile object and other information on the travel is input, end lines are searched, calculated, output and displayed.
A path reaching to the target is indicated as an end line 1 , a path reaching to the end line 1 as an end line 2 , a path reaching to the end line 2 as an end line 3 and, sequentially, a path reaching to an end line ‘n’ is indicated as an end line ‘n+1’.
In the case where the target is an area, not a point, or a point in an area, there will be two or more end lines 1 in some cases.
For some target point, an end line thereof is stored as data in a memory unit and when the target point is set as a target, the data is retrieved together with the target point and the end line is output to be displayed.
Alternatively, when a target is set, searching is done by searching a path on which the target is located and indicating it as an end line 1 , indicating a path having a crossing with the end line 1 as an end line 2 , indicating a path having a crossing with the end line 2 as an end line 3 and indicating a path having a crossing with an end line ‘n’ as an end line ‘n+1’ sequentially in this way.
When the current position moves to other end line ‘n’ and ‘n’ is a smaller number than before, it means that the position became closer to the target. Therefore, to notify the user of this, it is preferable to display it emphatically by changing colors and types of the end lines or a background color, or notifying by a character, signal, sign or voice guidance, etc. By displaying a part of the end lines differently or displaying a part of an end line differently, strain on the user trying to recognize it can be reduced. To cite an example, when the current position is on the end line 1 , the situation of approaching to the target can be notified by a background color, voice or sound, etc. as the current position gets closer to the target.
A part of the end line may be emphasized by displaying differently.
On the contrary, when ‘n’ becomes larger, it means that the possibility of reaching the target is lowered, therefore, it should be displayed in an appropriate emphasized way.
Alternatively, an end line ‘n’ where the current position is and end lines having larger numbers than ‘n’ may be displayed in an indistinctive way, while end lines with smaller numbers than ‘n’ may be displayed emphatically with images and sounds.
When one path has different numbers ‘n’ at the same time, it can be chosen arbitrarily which number, the upper number or lower number, to be prioritized for display.
For example, ‘n’ is to be displayed and ‘n+1’ is not displayed, or the opposite example may be mentioned.
When searching an end line ‘n+1’ from an end line ‘n’, a condition may be set for a rank of path such that a width of the road has to be equal or wider.
When a path having a crossing with an end of the end line ‘n’ is ‘n+1’, it is likely that a road width of ‘n+1’ is equal or wider than that of ‘n’ in general.
In this example, when road data is provided as link data, a link group which shares an end point of a link sequence of the end line ‘n’ as crossing is considered as ‘n+1’ and searching may be done within the link data based thereon.
Generally, it is preferable that end lines of fixed targets in particular are stored as data in the memory unit.
In an area with lots of regulations on direction or irregular-shaped paths, targets and end lines are stored together as data in the memory unit in advance.
An area of displaying end lines may be decided arbitrarily according to a density of paths and regulations on direction in the area.
When end lines overlap, they may be displayed in an imposed way or only ‘n+1’ or ‘n’ may be displayed. Alternatively, only ‘n+1’ may be displayed, but it may be changed to display only ‘n’ when the mobile object moved to ‘n’.
Also, an end line on which the current position is may be displayed emphatically.
There are other combinations, and high-order end lines and low-order end lines are treated in the same way.
When there are a plurality of end lines ‘n’ displayed and a mobile object moves in on one of the lines, if other end lines ‘n’ are not shown, the display can be simplified. In this example, lines of ‘n+1’ or larger are not displayed. When the mobile object got out of the end line, all the end lines are displayed.
For example, when the mobile object moved in on one of end lines 4 , other end lines 4 are erased.
Alternatively, following regulations on direction, the end line 1 may be displayed in the regulation direction up to the target, and, on other end lines, an end line ‘n+1’ may be displayed in the regulation direction up to an intersection point with an end line ‘n’.
When the mobile object moves in on an end line ‘n’ from an end line ‘n+1’, the end line ‘n+1’ is preferably all erased so as to simplify the display.
As to end lines, by displaying only an end line ‘n’ where the current position is and not showing other end lines ‘n’ so as to display with end lines with smaller numbers than ‘n’, only significant end lines for reaching the target and the end line of the current position are displayed, and visibility of the display is improved thereby.
End lines with larger numbers than an end line ‘n’ are not displayed or displayed with an unnoticeable color or type of line.
When the mobile object moves in on an end line with a larger number than ‘n’, logically the same processing is performed.
There may be a large number of combinations in reaching to the end line ‘1’ from an end line ‘n’ in some cases.
In that case, some combinations may be selectively displayed to simplify the display.
In an area with complex-shaped paths and lots of regulations on direction, reaching to a target point is hard and it is not favorable as a location for a commercial facility.
When setting the facility as a target point, registering end lines thereof as data, adding a navigation code and notifying visitors by putting it down on business cards, brochures, on the Internet or by some other means of giving notification, it can be used as a new type of advertisement having an invitation function.
It can be streamlined by providing a communication function to a portable device or in-vehicle device and distributing a navigation code from the center or, as to the registered facilities, it can be streamlined by sending information relating to a registered facility to the center and distributing a target point and end lines thereof.
It is preferable that a color and type of line of each end line are made different and the line display including the background is designed ingeniously for each stage according to move of the mobile object so as to improve discrimination and entertaining variation.
By using a background color, colors and types of lines, sound effects and some characters, etc., it is possible to make it seem like playing a game, so that it becomes easier for the driver to recognize that the possibility of reaching to the target point is getting higher as the number ‘n’ becomes smaller.
Displaying in combination of two dimension and three dimension, emphasis and erasure of lines, etc. may be devised. It is preferable to design the presentation in accordance with a range and scale reduction of a displayed area. Also, expressions according to attributes of roads, such as a width, regulation and management, may be added.
Display and erasure of each of the end lines 1 to ‘n’ may be expressed as required by the user, as well.
INDUSTRIAL APPLICABILITY
The navigation device can be used by all mobile objects and applied for in-vehicle use in addition to portable use, by which it is possible to reach a target point safely and efficiently.
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End lines are ingeniously displayed so as to enhance the function of reaching a target without impairing safety. Visibility is improved and the driver is assisted to select a route, so that reaching a target is ensured. At the same time, the driver's burden is reduced and thereby safety is enhanced.
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The U.S. Government has rights in this invention pursuant to NIH Grant No. DE08144.
BACKGROUND OF THE INVENTION
A. Field of the Invention
The present invention relates generally to the field of cell culture. In particular, the invention relates to devices and methods that allow for the growth maintenance of cell cultures at high cell density. Some aspects of the invention involve a perfusable culture device designed so that a constant culture media level is maintained. Other aspects of the invention involve the use of the devices of the invention for time-lapse cinemicrography.
B. Background of the Related Arts
Traditional tissue culture procedures involve growing or maintaining cells in liquid or on solid media in culture flasks. One of the limitations of this type of system has been the fact that it is difficult to grow high-density tissue cultures in such a system.
Cells maintained in culture systems frequently have defined and stringent nutrition needs. In order to meet these needs, it has been necessary to maintain a relatively high media-to-cell ratio. Otherwise, the cells rapidly deplete the media of nutritive components and fill the media with metabolic waste. Further, CO 2 gas bubbles build up and obscure the growing cells when one attempts to grow the cells to high density. This leads to difficulty in recording the growth of cells in culture via time lapse photography.
In order to forestall these problems, traditional cell culture has involved growing cells until they are just confluent, then trypsinizing the cells to remove them from the culture vessel and placing a portion of the cells in a new vessel with fresh media. Allowing cells to grow into a higher density is difficult with flasks because once the media becomes low in nutritive value, the cells either die or grow in aberrant manners. There is a current need in the field of cell growth research, e.g. in clinical organogenesis, for a system which allows for the growth of dense tissue cells which are multiple cell-layers thick. One favorable characteristic of such a system could be that it would maintain a constant level of culture media within the device. Unfortunately, there has been no system which readily permits such a constant culture media level.
Another form of culture used by researchers is organ culture, where whole or sliced animal organs are grown in culture media. Organ culture confronts the same problems as cell culture in that the need for nutrients requires a high media-to-cell ratio. Further, organ culture also confronts problems because it is difficult to diffuse nutrients into the center of thicker masses of organ tissue.
One of the current frontiers in the field of cell growth is the study of how cells live and grow in vivo. In vivo, cells are in contact with each other, many of the cells are quiescent, and cells undergo morphogenesis into various tissue types. Each of these states of cell growth and development has been difficult to observe in traditional tissue culture systems. The known culturing systems have not allowed cells to be grown until they reach a quiescent state where morphogenesis can occur. This is because of the constant need to cycle cell media and reduce the number of cells. Further, it has been difficult to study and perform organogenesis, a subset of morphogenesis. In organogenesis, a population of cells morphologically differentiates such that an organ is formed. While there has been some limited success at growing very thin, often single cell thick, layers of skin for medical use. The growth of thicker tissues and organs for clinical use has proven difficult. A large part of this difficulty has been the inability to constantly supply nutrients to the growing cells in a system where the media-to-cell ratio is low.
Time lapse cinemicrography devices provide a valuable tool for the study of cell growth and differentiation. While systems for such studies have been known, the data obtained have been limited since only low density cell cultures have been grown for long periods of time. The prior art tissue culture chambers are not suited for growing high density tissue cultures for periods long enough to allow for tissue morphogenesis to occur.
Prior time lapse cinemicrography studies have usually involved observation of individual cells at high magnification. In such studies, cells have been maintained at very low density since many microscopic features of cells are obscured under confluent conditions. For such studies, the Rose (Rose 1954) and Sykes-Moore chambers (Sykes, et al., 1959) have proven to be quite satisfactory. The present inventors attempted to use the Sykes-Moore chamber for time-lapse studies of cells maintained at very high cell density and found that several problems occurred even when the Sykes-Moore chamber was perfused several times a day with medium delivery by a peristaltic pump. The chief problems encountered were the production of CO 2 gas bubbles which interrupted the optical path and resulted in constant defocusing of the system due to the deformation of the coverslip walls of the chamber.
Time-lapse cinemicrography studies of cells maintained at very high cell density in Sykes-Moore chambers even with a medium perfusion system, gave unsatisfactory results for several reasons. First, CO 2 produced by cells led to the formation of gas bubbles which often obstructed the optical path. Second, the specimen regularly went out of focus due to gas pressure build up which caused the glass coverslips to warp, and, in some cases, break. Third, after several days cells underwent degenerative changes apparently due to lack of oxygen.
To observe morphological changes in cells maintained at high cell density studies were initiated with Sykes-Moore chambers. In such studies, MDCK cells were planted in Sykes-Moore chambers that had been completely filled with medium and connected to a peristaltic pump which perfused the culture. Gas bubbles formed once cells had become confluent and that the microscope appeared to continually go out of focus in spite of several attempts to bolster the stage lock mechanism.
By sealing all orifices with silicone rubber glue, it was determined that the formation of gas bubbles was not due to a leak in the peristaltic pump tubing or chamber itself. The present inventors concluded that the gas bubbles were due to CO 2 produced by the cells. The constant problem of the microscope going out of focus was determined to be due to CO 2 pressure deforming the glass coverslips that make up the top and bottom of the Sykes-Moore chamber. Indeed, on several occasions, the glass coverslips of the Sykes-Moore chamber split due to gas pressure build-up.
These problems caused the Sykes-Moore chamber to be of use for only about one day when observing cells at moderately high density. This is too short to allow for dense cultures to grow and for meaningful time-lapse micrography.
The failure of existing technology forced the present inventors to develop a new culture apparatus that would allow cells to grow to high cell density and allow long-term time-lapse cinemicrography.
Initially, Applicants attempted to maintain a constant media level in profusion chambers by having a single culture media inlet and a single culture media outlet, both positioned below the desired fluid level. The idea was that if culture media could be pumped into the device at exactly the same rate it was being pumped out of the device, a constant fluid level would be maintained. While theoretically workable, this configuration proved to be very difficult to place in practice. It was found to be almost impossible to obtain exactly equal inflow and outflow of the media. Therefore, over a period of time, the culture chamber would either fill with media or be drained below the desired level. This can cause at least two problems: (1) cells die in an empty chamber, and (2) even if the chamber were not to become completely empty or full, a constantly shifting media level will obscure the focus necessary for time lapse micrography.
Confronted with these problems, the present inventors created a simple, dependable, and inexpensive system for maintaining high density tissue cultures for a long period of time.
SUMMARY OF THE INVENTION
A simple culture chamber is described which permits cells to be maintained at very high cell density for a week or more. This simple culture vessel allows for long term observation of cells at extremely high cell density and permits an unobscured view of cells for over a week.
In general, the invention relates to a perfusable culture device capable of maintaining a substantially constant culture media level. This device allows for either continuous or intermittent cycling of the media through the culture device. Therefore, fresh media containing nutrients is available to cells growing in the culture device, while aged media collected waste is gradually removed from the culture device. During use, the culture device is typically connected to a pump, which allows the use of a culture media inlet system for injection of new media and a culture media outlet system for the withdrawal of old media on a continuous or intermittent basis. With some applications, it may be desirable to continually pump media into and out of the system. With other applications, it might be desirable to change the medium in the system every few hours or days. Regardless of the timing of the media circulation, the present culture device allows for circulation of the medium in the chamber without disrupting the cells or opening the chamber while maintaining a constant media level.
Generally, the perfusable culture device has a chamber, at least one culture media inlet which flows into the chamber, and at least one culture media outlet which flows out of the chamber.
The chamber can be of almost any liquid-containing material, and can be of almost any shape. For example, the chamber can be made of plastic, glass, metal, or the like. Usually, it will be advantageous to make the chamber out of a transparent material, so that the growing cells can be observed. Further, it is anticipated that plastic or other inexpensive material will be most often employed in the manufacture of the chamber. These materials lend themselves to easy manufacture and are relatively inexpensive such that the culture devices can be disposable. Of course, should certain desirable property qualities be desired, for example, improved optical qualities which could only be obtained with optical quality glass, the chambers may be made of material with these qualities. The chambers may be cylindrical, round, square, rectangular or irregularly shaped. Typically, they will be somewhat flattened so that there is a large service area between the gas space above the media and the media. A large surface area at the bottom of the chamber aids in providing a large space for the growing cells to rest upon. The chamber should be sealable so that microorganisms do not contaminate the culture. The chamber may be fitted with a gas inlet and/or outlet that serves to flow gas to and/or from the chamber and maintain the proper atmosphere. A small gas pressure relief fitting may be included to permit venting of CO 2 produced by the cells and to allow air into the system.
In a preferred embodiment of the invention, the chamber will be shaped much as a typical cell culture flask is shaped, e.g., a flattened bottle which is designed to lie on its side and has a neck with a cap on it at one end. Such flasks are well known in the art. Perfusable culture devices according to the invention shaped like culture flasks have the advantage of fitting in and on existing laboratory culture equipment.
There are many different innovations and designs of tissue culture flasks which may be employed as the basis for the present culture device. For example, Lyman, et al., U.S. Pat. No. 4,927,764 details a flask which has improved optical qualities and a top wall which has a large opening covered by a flexible transparent film which can be peeled off to provide access to the flask interior. Carver, U.S. Pat. No. 4,334,028, discusses a flask with a frangible zone formed into the top wall, which allows for easy access to the contents of the flask. Lyman et al., U.S. Pat. No. 4,770,854, describes a laboratory flask with a ramp that allows accessibility to the four corners of the rear wall and the four corners of the growing surface for a scraper. Honda et al., U.S. Pat. No. 5,139,952, describes a flask shaped such that a scraper can reach the entire bottom of the surface area through the neck. These U.S. patents are incorporated by reference herein, for their teachings related to culture flasks. Each of the flasks described above has features which should be of benefit when used in conjunction with Applicants' perfusable culture device. Since the culture device is essentially a culture vessel modified so that culture media can be circulated through it, the advantages of the prior art flasks, when incorporated into the invention, are clear.
The culture media outlet is typically a tube that passes through the wall of the chamber into the interior of the chamber. The outlet allows media to be pumped out of the chamber. The outlet has an exterior portion which is adapted to receive a hose or tube which runs to a pump. The outlet has an interior portion that has a port at the desired media level. The culture media outlet may be formed of metal, glass, plastic, etc. In preferred embodiments of the invention, the culture media inlet enters the chamber in the gas space above the desired liquid level and extends downward to the desired liquid level. This positioning of the culture media outlet prevents liquid leakage at the juncture of the outlet and the chamber wall, and does not interfere with the positioning of the flask on a supporting surface. More than one culture media outlet may be employed in the device, and not all culture media outlets in a device must have a chamber interior port which is positioned at the desired culture media level. Rather, so long as one port is positioned at the culture media level, other ports may be positioned below the desired media level.
The perfusable culture device must have at least one culture media inlet leading from the exterior of the chamber to the interior of the chamber. This inlet is designed so that media can be pumped into the chamber. The inlet may be constructed of any of the materials from which the outlet can be constructed, and is, like the outlet, typically a tubular passage. The culture media inlet has a chamber interior port through which media passes into the chamber. Typically this port is positioned below the desired fluid level, so that the flow of media into the chamber does not disrupt the surface of the fluid. However, in certain applications it may be desirable to position the port above the desired fluid level so that the incoming media drops down into the supply of media in the chamber. The culture media inlet is typically hooked up to a pump which pumps media into the chamber on either a continuous or intermittent basis. The inlet typically enters the chamber in the gas space above the desired liquid level and descends into the media. In this manner, leaks from the junction of the inlet and the chamber are minimized. Of course, more than one culture media inlet may be present in a single device.
One of the inventive aspects of the present invention is its ability to maintain a constant culture media level. A constant level is maintained due to the difference between the media inlet and media outlet capacities of the device. The device is designed so that at least one culture media outlet port is positioned at the desired culture media level and quickly removes any media which would raise the media level above the desired level. This requires that the media outlet capacity is greater than the media inlet capacity. The culture media outlet capacity is determined by summing the total rate of media removal from all of the outlets of a single device. The culture media inlet capacity is the sum of all of the rates of media input from all inlets.
In order for the device to maintain a constant level, the culture media outlet with the media level port positioned at the desired level syphons away any excess media before the fluid level can be raised.
The culture media outlet with the media level port draws fluid only when there is sufficient fluid in the chamber to contact the port. During use, the culture media inlets function to add media to the chamber until the level of the culture media outlet's port at the desired fluid level is reached. At that point, because the culture media outlet capacity is greater than the culture media inlet capacity, any additional fluid that flows into the chamber from the inlets, it is immediately removed and constant fluid level is maintained.
Additional culture media outlets can be used to syphon media from below the desired culture media level, so long as the capacity of any sublevel culture media outlets is less than the capacity of all of the culture media inlets. If the sublevel outlets had a greater capacity than the media inlets, then the fluid level would be reduced to the level of the sublevel outlets. An outlet that has a port at the bottom of the chamber can remove small debris which form during the prolonged cultivation of cells. The fluid level outlet, being positioned at the air-liquid interface, will not remove such small debris. The presence of the bottom level port removes debris which would settle down to the cell layer, and this is of particular use during time-lapse studies where debris could obscure the image of the cells.
In some preferred embodiments of the claim device, there are two culture media inlets. The advantage of this system is that, should one inlet become clogged, the other inlet will permit the continued flow of media into the chamber, albeit at a slower rate.
In certain preferred embodiments, the perfusable device will have two culture media outlets and two culture media inlets, such that the advantages of both of these configurations systems are realized.
The perfusable culture device is typically hooked up to a pump, such that media is pumped into the chamber through each culture media inlet and media is pumped out of the chamber through each culture media outlet. As previously stated, the outlet pump capacity must be greater than the inlet pump capacity in order for the culture device to function properly and maintain a constant media level. Further, the outlet capacity of any below media surface outlets must be less than the total inlet capacity.
A variety of pumps may be used in conjunction with the perfusable culture device. However, it is anticipated that peristaltic pumps will be one of the most convenient forms of pumps to use. Peristaltic pumps are available from many companies, including Masterflex® and Ismatec®. One advantage of peristaltic pumps is that the flow rate from a single culture media outlet or culture media inlet can be controlled by the diameter of tubing attached to that outlet or inlet. Therefore, in order to get an outlet capacity which is greater than the inlet capacity, it is merely necessary to use a larger bore tube attached to the culture media outlet than is attached to the culture media inlet. In one embodiment of the invention, the inventors attach tubes of equal bore to two culture media inlets and a submedia outlet. A larger bore tube is attached to the culture media outlet whose port is at the desired media level. When the tubes are hooked to individual heads on a multihead peristaltic pump, this result is that the culture media outlet capacity is greater than the culture media inlet capacity and the system maintains a constant fluid level. Of course, the invention is in no way limited solely to the use of peristaltic pumps or this manner of controlling the rate of flow, and those of skill in the art will appreciate that there are numerous equivalent arrangements.
Other embodiments of the present invention involve methods of culturing cells at high density. These methods involve obtaining a culture device and adding culture media and cells to be cultured, attaching the culture media outlet(s) and culture media inlet(s) to a pump, and perfusing the chamber by either constantly or intermittently pumping culture media into the chamber through the inlets and pumping culture media out of the chamber through the outlets, thereby maintaining the desired media level in the chamber while replenishing the nutrients in the media and removing waste on a regular basis. The culture device is then placed in a situation facilitating or allowing for cell growth and the cells are allowed to grow.
Other embodiments of the present invention involve methods for performing time-lapse cinemicrography of cell cultures. Using the device of the present claims, it is possible to maintain focus of cells growing at high density for long periods of time. This device avoids CO 2 gas bubbles from obscuring the focus and also avoids lack of nutrients and waste accumulation from causing cell growth problems. This cinemicrography is performed by growing cells according to the methods defined above, with the culture device being placed upon the stage of a microscope. Typically, an inverted phase microscope is used. The optical quality of culture devices made of standard culture flask materials is sufficient to allow for observation at 10 to 400 times magnification. 100 times magnification is typically employed by the inventors in their studies. It is possible to obtain higher magnification microscopy, however, with magnifications of 1000 times or more, one might wish to employ a flask or culture device which has improved optical qualities. Such a flask is detailed by Lyman, et al. in U.S. Pat. No. 4,927,764 which is incorporated by reference herein. A camera may be set up to record the course of cell growth through the microscope. Either a film camera or a videotape camera may be employed in this manner. By using a motion picture camera and a timer or a time lapse VCR, it is possible to obtain time-lapse photography of the cells.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain aspects of the invention will become more clear upon the viewing of the accompanied drawings.
FIG. 1 A perspective view of an embodiment of the perfusable culture device.
FIG. 2 A top view of embodiment of the perfusable culture device.
FIG. 3 A side view of embodiment of the perfusable culture device.
FIG. 4 A view of one embodiment of the culture device hooked up to a peristaltic pump in an operating configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following examples detail specific embodiments of the claimed invention. Those with skill in the art will understand that many non-inventive variations of these devices and methods are possible. These variations are within the scope of Applicants' invention and the claims are in no way limited to those embodiments detailed in this section of the application.
The device eliminates problems inherent in existing time-lapse cinemicrography chambers that prevent the use of existing devices for cell cultured at high cell density. Production of CO 2 gas by cells grown to high density is sufficient to warp a glass coverslip, resulting in the specimen going out of focus. Warping can become so extreme that the glass coverslips of past systems crack. The device has the addition advantage of allowing one to grow tissue cultures to high density while maintaining a constant volume of medium in the device during frequent automatic medium changes.
EXAMPLE I
Flask-Shaped Culture Profusion Device
One embodiment of the present invention is a flask-shaped, perfusable cultural device. Such a device is illustrated in FIGS. 1, 2 and 3. As can be seen, the device has the general form of a culture flask. The device is typically made of clear plastic material, although it may be made of glass, metal or another non-permeable material. For use in cinemicrography, transparent materials are preferred. Plastic flasks are typically manufactured by injection molding, a technique which is well-suited to the manufacture of the device of the embodiment since it is possible to injection-mold the flask, along with its inlets and outlets. The specifics of the flask-shaped perfusable culture device are as follows.
Perfusable culture device 10, has chamber portion 30, outlets 40 and 50, inlets 60, and neck region 20.
Chamber portion 30 has bottom 32, top 34, side walls 35, rear wall 36, and neck proximal walls 38. Neck 22 projects at an upward angle from neck walls 38. The chamber typically has a 25 cm 2 surface area.
Neck region 20 comprises neck 22 and cap 24. Neck 22 is designed such that cap 24 screws or snaps securely onto neck Cap 24 may form a gas-tight seal between itself and neck 22, because tissue culture often requires a specific gas environment above the tissue media. For example, a 5 to 10% CO 2 concentration is often required for cell culture. In order to help maintain the desired gas environment by allowing excess CO 2 to escape, vent 48
Top outlet 40 is a tubular outlet having external port 42 and internal port 44. In the Figures, top outlet 40 is formed of a hypodermic needle with the Leur-lock fitting still in place. In FIGS. 1 and 2, top outlet 40 enters chamber 30 through top 34. Top outlet 40 is positioned such that internal port 44 is at the desired media liquid level. While top outlet 40 can enter chamber 30 from any angle through any wall or side, it is preferable that top outlet 40 enter the chamber in gas space 70, so that any media leaks between the juncture of top outlet 40 and chamber 30 are minimized. Top outlet 40, as with other outlets and inlets in the invention, can be made of varying materials. The inventors have used metal outlets which have been cemented or glued in place in some prototypes of the invention. These outlets have worked well, however, it is somewhat difficult to obtain a solid seal between the metal outlets and the plastic chamber wall. The inventors have helped remedy this problem by bending outlets and inlets at the portion that passes through the wall of the chamber. When these bent outlets and inlets are glued in place, they are difficult to pull out, and a solid seal is achieved. Applicants anticipate that outlets can be injection molded at the same time as the chamber, thereby forming a continuous piece of plastic-type material forming both outlets 40 and 50, inlets 60, and chamber 30.
Outlet 50 has external port 52 and internal port 54. Internal port 54 is positioned such that it is below the desired liquid level 74. Outlet 50 can enter chamber 30 through any wall or side. In the illustration, outlet 50 enters the chamber through side wall 35. Although the illustration shows outlet 50 entering the chamber below the desired fluid level 74, if outlet 50 enters the chamber in gas space 70 and then extends below liquid level 74, the risk of leakage between the junction of outlet 50 and chamber 30 is reduced. Outlet 50 is not a required part of all embodiments of the invention. Outlet 50, when employed, may serve to remove debris from the bottom of the flask.
Inlets 60 allow for culture media to be fed into chamber 30. This embodiment of the device has two inlets 60, thereby having a back-up should one inlet become clogged. Inlet 60 has external port 62, and internal port 64. Inlet 60 can enter chamber 30 through any wall or side, however, in the illustrated embodiments inlets 60 enter the chamber through side wall 35. As with outlets 40 and 50, certain advantages are realized if inlets 60 enter chamber 30 in gas space 70 and then pass into the media reservoir.
The combined capacity of outlets 40 and 50 must be greater than the combined capacity of inlets 60 in order for a constant media level to be maintained. Further, in order for the constant media level to be maintained at the level of internal port 44, the capacity of outlet 50 must be less than the combined capacity of inlets 60. The inventors have obtained these differences in capacity by hooking a peristaltic pump with the outlets and inlets of the same diameter to tubing of appropriate diameters. During use, outlets 40 and 50 are hooked up to a pump such that media can be moved from the flask through them. As shown in FIG. 4, fluid level outlet 40 is hooked up to fluid level outlet tube 41, and outlet 50 is hooked up to outlet tube 51. Inlets 60 are hooked up to a pump and media reservoir via inlet tubes 61, such that media can be introduced into the chamber through them. When the pump(s) is operating, outlet 40 functions to maintain a constant media level. As additional media is added through inlets 60, outlet 40 syphons away any media rising to the level of outlet port 44. Since the total outlet capacity is greater than the total inlet capacity, but the capacity of outlet is less than the capacity of inlets 60, the media level will constantly be maintained at the level of port 44.
During use, for the device may be placed in the configuration shown in FIG. 4. The device 10 is placed upon the stage of a microscope 90. Inlet tubes 61 are attached to the media inlets 60. Outlet tube 41 is attached to fluid level outlet 40, while outlet tube 51 is attached to outlet 50. Inlet tubes 61 are connected to pump 80, in such a way that they can draw fresh media from media reservoir 65. Outlet tubes 41 and 51 are connected to pump 80 and then to waste media container 45. A camera can be positioned so as to allow for still pictures or cinemicrography.
EXAMPLE II
Manufacture and Use of a Prototype Culture Chamber
Materials
A. Equipment-although brands of equipment and some model numbers are given, Applicants in no way limit their claims to these specific pieces of equipment.
Peristaltic pump, Model G-07521-50, Cole Parmer
Four Easy-Load pump heads, Model G-07518-00, Cole Parmer
Timer, 6 events/day, 1 minute resolution,
Inverted phase microscope,
Television camera,
Time lapse tape recorder, Panasonic
CO 2 -incubator, National Appliance
37° C. warm room (or similar devise for maintaining cultures at 37° during time lapse observations).
B. Supplies
PharMed® peristaltic pump tubing, size 13, Cole Parmer 1
PharMed® peristaltic pump tubing, size 14, Cole Parmer 1
Tissue culture flasks, Corning® 25 cm 2 , Model 251107??
16 gauge hypodermic needles,
Glue
Procedure
Preparation of Liquid Level Control for Culture Flask
1. Cut the Leur-lock plastic fitting off of the 16 gauge needle. The inventors hold the needle in a small vice and cut the plastic fitting off with a hack saw. The needle is bent at the point it enters the flask to reduce the chance of the needle being accidentally pulled out of the chamber.
2. Mark the side of the flask at the intended liquid level with a marking pen.
3. Using a drill bit or a red hot gauge needle, make four holes in the sides of a Corning 25 (well above the intended liquid level) and one hole was placed in the top of the flask.
4. Three 16 gauge needles prepared as described in (1.) above were inserted into the three side holes in the flask such that the beveled needle opening faced the bottom of the flask. The needle should be inserted such that the needle opening will be constantly submerged at the intended liquid level. Glue the needles in place with glue.
5. Insert the cut end of a 16 gauge into the top hole of the flask such that the end of the needle is at the intended liquid level and the glue the needle in place with glue.
Planting Prototype Chamber with Cells
1. After the glue has dried, sterilize the flask by, for example, rinsing with Chlorox®, 95% ethanol, and sterile water.
2. Plant cells at the desired cell density.
3. Connect the needle together with two sterile pieces of PharMed® tubing to prevent entry of undesired organisms into the flask during the remaining steps.
4. Add 10 ml culture medium, for example Dulbecco's MEM, and the desired number and types of cells.
4. Place the flask in the CO 2 -incubator to establish the desired CO 2 -percentage. For example, 10% CO 2 may be used.
C. Connection of Prototype chamber to the Peristaltic Pump.
1. Connect the needle in the top of the flask to PharMed® size 14 tubing such that medium will be withdrawn from the flask through the needle.
2. Connect one needle in the side of the flask to PharMed® size 13 tubing such that medium will be withdrawn from the flask through the needle.
3. Connect the other two needles in the side of the flask with PharMed® size 13 tubing such that medium will be pumped into the flask through these needles.
Use of Chamber for Time Lapse Cinemicrography.
1. Focus the microscope on a region of the flask near an inlet needle to avoid the possible interference of the observations by cell debris. The fluid flowing through the inlet needle will push away debris for an area around the inlet.
2. Turn on the video camera and television monitor.
3. Focus the microscope and adjust lighting conditions.
4. Start the videotape recorder at the desired time lapse setting.
5. Program the timer to deliver a desired volume of medium at desired intervals.
Discussion of Use and Operation of Prototype Chamber
In making an exemplary model of their perfusable culture chamber, the inventors modified a standard 25 cm 2 culture flask so that medium could be perfused into the flask without altering the liquid level. Maintenance of a constant liquid level is essential in order to keep a cinemicrography chamber containing a specimen in focus. The prototype device operates as follows.
Medium is pumped into the chamber through two narrow bore (size 13) pieces of PharMed tubing. Medium is withdrawn from the chamber by one narrow bore size 13 tubing and one piece of larger bore size 14 tubing which is connected to the needle in the top of the flask. At the selected peristaltic pump speed (setting 4.0), each size 13 tubing has a flow rate of 2.6 ml/min while the size 14 tubing has a flow rate of 10.1 ml/min. Hence, the two size 13 inlet tubings have a net flow rate of 5.2 ml/min while the size 13 plus size 14 outlet tubing have a maximum flow rate of 12.7 ml/min. Liquid level is maintained at the level of the opening of the top needle for two reasons. First, medium can never be entirely depleted from the chamber since the two size 13 tubings are used to pump into the chamber and only one size tubing is used to pump from the bottom of the chamber, (once the liquid level falls below the level of the needle positioned in the top of the flask, no liquid can be withdrawn by the size 14 tubing. Second, medium can never go above the level of the top outflow needle since the maximum inflow rate is 5.2 ml/min while the maximum outflow rate is 12.7 ml/min. Note that the size 14 tubing port only withdraws medium from the chamber on an intermittent basis. Hence, this system maintains a constant liquid level.
There are several designs for a peristaltic pump heads currently on the market. Where two different sizes of tubing are used by one pump, it is advantageous that the pump use the independent pump heads rather than a single pump head that can accept several pieces of tubing. In the case of pump heads that accept several pieces of tubing, a screw or similar devise is used to apply pressure to tubing, and it is difficult to accurately set the flow rates of two different sized tubings.
The times at which the pump turns on and off and the interval during which it is active can easily be set by a household timer which supplies current to the pump during desired time intervals. The inventors have used an inexpensive timer allowing them to turn the pump on and off for intervals as short as 1 min. Using such a system, it is possible to automatically feed cultures with desired volume of medium at multiple times/day or continuously during the day.
The inventors have used the device described above to observe cells maintained at confluence for over a week without the specimen going out focus even when 200× magnification was used, thereby demonstrating the usefulness of the invention in time-lapse micrography studies.
The foregoing examples are provided to illustrate some of the preferred embodiments of the claimed invention. Of course, those of skill in the field will understand that many variations of the described invention are possible without departing from the spirit of the invention. All such variations are also considered to be within the scope of the invention.
References
The following articles and patents are incorporated by reference in pertinent part herein.
Carver, "Flask," U.S. Pat. No. 4,334,028, 1982.
Honda et al., "Tissue Culture Flask, " U.S Pat. No. 5,139,952, 1992.
Lyman, "Tissue Culture Flask," U.S. Pat. No. 4,927,764, 1990.
Lyman, "Laboratory Flask," U.S. Pat No. 4,770,854, 1988.
Rose, "A Separable and Multipurpose Tissue Culture Chamber," Tissue Culture Laboratory, 1075-1083, 1954.
Sykes et al., "A New Chamber for Tissue Culture," P.S.E.B.M., 125-127, 1958.
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The present application relates generally to methods and devices allowing for high density tissue culture techniques to be practiced. Specifically, the application relates to a perfusable culture device which allows for the maintenance of high-density tissue cultures. The application also details methods of using the device to grow cells of varying densities, and methods of observing cell growth at high densities with time-lapse micrography.
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FIELD OF THE INVENTION
This invention relates to layered antennas and in particular relates to antenna cross-polar suppression means.
BACKGROUND TO THE INVENTION
Cellular radio systems are used to provide telecommunications to mobile users. In order to meet the capacity demand, within the available frequency band allocation, cellular radio systems divide a geographic area to be covered into cells. At the centre of each cell is a base station through which the mobile or fixed outstations communicate with each other and with a fixed (wired) network. The available communication channels are divided between the cells such that the same group of channels are reused by certain cells. The distance between the reused cells is planned such that co-channel interference is maintained at a tolerable level.
When a new cellular radio system is initially deployed operators are often interested in maximising the uplink (mobile station to base station) and downlink (base station to mobile station) range. Any increase in range means that less cells are required to cover a given geographic area, hence reducing the number of base stations and associated infrastructure costs. The downlink range is primarily increased by increasing the radiated power from the base station. National regulations, which vary from country to country, set a maximum limit on the amount of effective isotropic radiated power (EIRP) which may be emitted from a particular type of antenna being used for a particular application. In Great Britain. for example. the EIRP limit for digital cellular systems is currently set at +56 dBm. Hence the operator is constrained and, in order to gain the maximum range allowable, must operate as close as possible to the EIRP limit. without exceeding it.
One form of layered antenna (an antenna having ground planes, feed networks and dielectric spacers arranged in layers) is known from British Patent GB-B-2261554 (Northern Telecom) and comprises a radiating element including a pair of closely spaced correspondingly apertured ground planes with an interposed printed film circuit, electrically isolated from the ground planes. the film circuit providing excitation elements or probes within the areas of the apertures, to form dipoles, and a feed network for the dipoles. A sectional view of such an antenna is shown in FIG. 1: a frontal view of the first three radiating elements is shown in FIG. 2.
The array antenna is constructed of a first apertured metal or ground plane 10, a second like metal or ground plane 12 and an interposed film circuit 14. Conveniently the planes 10 and 12 are fiat, thin metal sheets, e.g. of aluminium, and have substantially identical arrays of apertures 11 formed therein by, e.g. press punching. In the embodiment shown the apertures are rectangular and formed as a single linear array. The film circuit 14 comprises a printed copper circuit pattern 14a on a thin dielectric film 14b. When sandwiched between the apertured ground planes part of the copper pattern 14a provides probes 16, 18 which extend into the areas of the apertures. The probes are electrically connected to a common feed point by the remainder of the printed circuit pattern which forms a feed conductor network in a conventional manner. In the embodiment shown the totality of probes in the array form a vertically polarised antenna when the linear array is positioned vertically. In a conventional triplate structure the film circuit is located between and spaced from the ground planes by sheets of foamed dielectric material 22. Alternative mechanical means for maintaining the separation of the feed conductor network may be employed, especially if the feed network is supported on a rigid dielectric. Referring now to FIG. 2, the linear array comprises of a number of radiating elements 201 which have radiating probes 216 and 218 oppositely directed within aperature 210.
In order to increase output from the antenna in a primary radiating direction, the antenna may further comprise a further ground plane placed parallel with and spaced from one of the apertured ground planes to form a rear reflector for the antenna. Signals transmitted by the antenna towards the back plane are re-radiated in a forward direction.
Typically, for a cellular wireless communications base station, there is a linear arrangement of a plurality of spaced apart antenna radiating apertures/elements to form a linear array. It is often the case that an m x n planar antenna array is constructed from m linear arrays having n radiating apertures spaced at regular intervals. In cellular radio base stations, the antennas are generally arranged to cover sectors, of typically 120° in azimuth--for a tri-sectored base station. Each vertically oriented antenna array is positioned parallel with the other linear antenna arrays. The radiating antenna elements of a vertical array co-operate to provide a central narrow beam coverage in the elevation plane and broad coverage in azimuth, radiating normally in relation to the vertical plane of the antenna array. In the elevation plane the radiation pattern consists of a narrow "main" beam with the full gain of the antenna array, plus "side lobes" with lower gains. This type of antenna lends itself to a cheap yet effective construction for a planar array antenna.
Downtilt in the cellular radio environment is used to decrease cell size from a beam shape directed to the horizon to the periphery of the cell. This provides a reduction in beam coverage, yet allows a greater number of users to operate within a cell since there is a reduction in the number of interfering signals.
This tilt can be obtained by mechanically tilting the antenna array or by differences in the electrical feed network for all the antenna elements in the antenna array. Mechanical downtilting is simple but requires optimisation on site and can only provide a physical tilt, i.e. the beam shape with respect to the antenna is not changed; electrical downtilting allows simple installation and is a slightly more complex design. Electrical downtilt can be used to direct a radiation beam downwardly from an axis corresponding to a normal subtended by an array plane to form a conical beam pattern which provides an ideal coverage, especially in the case of tri-cellular antennas. The downtilt results from a consecutive phase change in the signal fed to each antenna element in an antenna array, i.e. the antenna can be said to have a progressive phase feed network. Typically, a downtilt of 2.5° or 5° is employed. but this can vary depending on the terrain local to a base station.
This progressive phase change (n°), however, introduces cross polar radiation currents (CPRC), as can be seen in FIG. 3, which can be compared with a non-steered flat plate antenna (i.e. having no progressive phase difference between the radiating elements). Cross polar radiation currents in turn provide gain associated with such cross polar radiation currents, and this reduces the required gain of the antenna in the azimuth direction. FIG. 4 provides a graphical representation of a loss in gain across a portion of the band attributable to cross-polar radiation.
Careful design of the dimensions of the apertures and the elements coupled with the design of the electrical characteristics of the feed network for the elements can control the cross-polar radiation to some extent, but this is not wholly effective. The Applicants have determined an antenna array providing electrical downtilt (whereby the feed network provides a progressive phase distribution for the radiating apertures), cross-polar radiation levels at resonant frequencies arise in the apertured ground planes which reduce the gain in the operating frequency band.
OBJECT OF THE INVENTION
The present invention seeks to provide an improved layered antenna with a progressive phase feed network and a method of operating the same.
SUMMARY OF THE INVENTION
According to the present invention there is provided a linear array layered antenna assembly the antenna comprising first and second apertured ground planes with an antenna probe feed network printed upon a dielectric substrate supported therebetween, the array of radiating elements having different phase input feeds, wherein an outwardly extending ground plane flange extends from one of the apertured ground planes, whereby resonant cross-polar fields are suppressed.
Preferably, the antenna further comprises a reflecting ground plane with a central planar portion spaced from the apertures a distance of λ/4 from and parallel with the apertures. Preferably, the reflecting ground plane portion has shoulder portions spaced in close proximity (of the order of millimeters) either side of the central portion, wherein longitudinal slots are formed in the shoulders parallel with respect to the axis of the longitudinal array, such slots being generally rectilinear or ellipsoidal. These slots extend in the region corresponding to the spaces between the apertures in the apertured ground planes.
In accordance with a further aspect of the invention. there is also provided a method ot receiving and transmitting radio signals in a cellular arrangement including a linear array layered antenna assembly the antenna comprising first and second apertured ground planes with an antenna probe feed network printed upon a dielectric substrate supported therebetween, the array of radiating elements having different phase input feeds, wherein an outwardly extending ground plane flange extends from one of the apertured ground planes;
wherein the method comprises, in a transmission mode. the steps of feeding signals from transmit electronics into the antenna radiating elements via feeder cables and, in a receive mode, the steps of receive electronics, the characteristic frequency of cross-polar radiation induced across the antenna being such that resonant cross-polar fields are suppressed in the desired frequency band of operation of the antenna, whereby gain in the desired frequency band of operation of the correct polarisation is maintained.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention can be more fully understood, reference shall now be made to the Figures as shown in the accompanying drawing sheets, wherein:
FIG. 1 is a sectional view of a first type of layered antenna;
FIG. 2 is a frontal view of part of the antenna shown in FIG. 1;
FIG. 3 is a frontal view of layered antenna with a non-uniform phase distribution in its feed network;
FIG. 4 is a graphical representation of the effects of cross-polar radiation in an antenna frequency band in a prior art antenna;
FIGS. 5i-iv are sectional and overhead views of two antenna reflector ground planes;
FIGS. 6i-ii are views of the apertured and reflecting ground planes in accordance with a first embodiment of the invention;
FIG. 7 is a graphical representation of the effects of the reduction of cross-polar radiation in an antenna frequency band in an antenna made in accordance with the invention;
FIG. 8 illustrates a detailed sectional view of an antenna array made in accordance with the invention;
FIG. 9 shows a view of an antenna facet, part cut-away.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The layered antenna element shown in FIG. 3 comprises an array of rectangular apertures 210 in first 20 and second (not shown) metallic ground plane. A dielectric sheet substrate supports a metallic conductor pattern consisting of a pair of radiating probes 216, 218 for each aperture and a common feed network (not shown) is positioned between the two spacers between the apertured ground planes. A feed point (not shown) is provided for connection to an external feed (also not shown). The feed network is positioned so as to form a microstrip transmission line with portions of the ground planes defining the rectangular apertures. The position of the feed point is chosen so that when an r.f. signal of a given frequency is fed to the network the relative lengths of the two portions of the network are such as to cause the pair of probes 216 and 218 to be fed in anti-phase, thereby creating a dipole antenna radiating element structure. Furthermore, the dimensions of the rectangular apertures and the bounding portions of the ground plane are chosen so that the bounding portions 28 parallel with the probes 216, 218 act as parasitic antenna radiating elements, which together with the pair of radiating probes determine the radiation pattern of the antenna.
The ground planes are spaced from the plane of the feed network by dielectric spacing means (as shown in FIG. 1) so that the feed network is spaced from both ground planes. Spacing between the network and the ground planes can be determined by foamed dielectric sheets or dielectric studs interposed between the various layers. Alternative mechanical means for maintaining the separation of the feed conductor network may be employed, especially if the feed network is supported on a rigid dielectric. The ground planes are conveniently formed from aluminum alloy sheet, by reason of its light weight, strength and high corrosion resistance, although metallised plastics may also be employed.
In a layered or flat plate arrangement the antenna arrays are arranged vertically to provide a beam which is narrow in elevation. The microwave signals from the base station transmitter are introduced or coupled to an antenna array feed network printed upon a dielectric substrate of an antenna by, typically, a coaxial line arrangement. The feed network provides a signal for each antenna element. The radiation pattern provided by each antenna element co-operates with the radiation pattern provided by the other antenna elements within an antenna array whereby the resulting radiation intensity distribution is the sum of all the radiation distributions of all the antenna elements within the antenna array. The antenna array can be deployed mounted on a mast or other type of suitable structure.
FIGS. 5i and 5ii show the differences in cross-section between an antenna 502 known from GB 9609265.5 (FIG. 5i) and an antenna 504 made in accordance with the invention (FIG. 5ii); FIGS. 5iii and iv show the respective differences in the reflecting ground planes. In FIG. 5ii, the uppermost apertured ground plane 506 possesses upstanding flange members 508. It is believed that the resonant frequency of the apertured ground plane is thereby decreased which reduces the frequency of the resonant cross polar radiation fields; FIG. 5iv shows slots 510 in the reflecting ground plane 512 in accordance with a preferred embodiment.
With reference to FIGS. 6i, 6ia and 6ii, there is shown in detail, respectively, the upper apertured ground plane 506, a sectional view thereof and reflector ground plane sheet 508 of a preferred embodiment of the invention. The reflector ground plane comprises a central portion 514 spaced a distance of λ/4 from and parallel with the apertures and shoulder portions 516 spaced in close proximity (of the order of millimeters) to the lower apertured ground plane either side of the central portion and from which the near field interference reduction flanges extend. The longitudinal slots 510 are formed in the shoulders 516 parallel with respect to the axis of the longitudinal array, such slots being generally rectilinear or ellipsoidal. It has been determined that for an antenna operating at 1900 MHz, square apertures of length 63 mm with a 105 mm spacing perform well with 53 mm long slots. These slots extend in the region corresponding to the spaces between the apertures in the apertured ground planes and have a width of 3 mm, and are spaced from the central portion by 3 mm. It is believed that these slots interrupt the cross polar surface fields induced on the reflecting ground plane and thereby reduce the effect of such. With respect to the apertures 522 on one shoulder of the reflector ground plane, these are associated with the termination of the coaxial feed cable which connects with the feed network on the dielectric sheet spaced between the apertured ground planes.
When the antenna operates in transmission mode, radio signals are fed to the antenna feed network by, for example. input/output feeds from a base station controller, via amplifiers. The feed network divides so that feed probes may radiate within areas defined by apertures in a ground plane of each antenna array. The feed network also induces phase changes for each successive aperture thereby providing electrical downtilt, which progressive phase change induces cross-polar radiation fields, the characteristic frequency of operation of which is changed by the flanges 508 and thereby such cross-polar radiation is removed out of the frequency of operation of the antenna, thereby not affecting the desired gain of the antenna. Flange 520 assists in reducing coupling effects between antenna arrays. FIG. 7 shows a graphical representation of the improved performance of the antenna: the dip in gain due to the cross-polar resonance has been shifted in frequency. out of the operating frequency band of the antenna.
FIG. 8 shows a cross sectional view of a preferred embodiment: the antenna 800 comprises a first apertured ground plane 802, first and second foamed dielectric spacers 804. 806 which support a thin dielectric sheet, not shown but indicated by arrow A. which dielectric sheet supports the radiating probes and electrical feed network, a second, lower apertured ground plane 808, third foam dielectric spacer 810 and a reflecting ground plane 812 Plastic clip fastener retaining means 814, 816 maintain the ground planes together and provide attachment to a support frame (not shown) respectively.
It is preferred that flange 818 extends from the outer apertured ground plane whereby construction is relatively simple; It is possible to fabricate this flange member from the inner apertured ground plane, but there would then be a risk that point contacts between the two apertured ground planes would arise, which would result in the output radiation being less well controlled due to discontinuities arising in joins between the two ground planes. In this embodiment, both the first apertured ground plane and the reflecting ground plane have flanges 818, 820 which extend outwardly beyond the radiating plane of the antenna extending from the arrays are formed as extensions from the reflector ground plane, the flanges associated with the reflector ground plane assist in reducing interference effects.
In a preferred embodiment, the arrays measure 1.7 m long and are 0.2 m wide. The apertures are of the order 40-70 mm square and the reflector plane is spaced 15-50 mm behind the dielectric feed network. The flanges 818 can vary in height from 10-40 mm, depending upon the desired properties of the antenna--if the flanges are too high, then the beam shape can be narrowed in azimuth to too great an extent The beam shape is. in any case optimised for a particular requirement by. inter alia, tuning the height and position of the flanges. In the case of tri-cellular or corner excited base stations, it is particularly advantageous that the beams are narrow in azimuth. It is possible, in a further embodiment to manufacture the outer apertured ground plane and the reflector ground plane from the same extruded tube: no point contact problems would be caused by discontinuities arising in joins between the two ground planes. Alternatively, wave soldering techniques could be employed whereby a continuous seal between the two component ground planes takes place.
FIG. 9 shows a facet 900 of a base station antenna made in accordance with the invention. The facet comprises four linear arrays 902 arranged in a parallel spaced apart relationship, with a radome 904 (shown part cut-away). The antenna arrays are mounted upon a frame 912. The support frame is conveniently a metal structure and of sufficient strength to support antenna arrays which may be subject to inclement weather conditions. Electrically insulating fasteners 814 connect the array components together; the arrays being attached to the supporting frame 912 by further electrically insulating fasteners 816. Dielectric foam 908 is placed in front of the arrays and functions as a load spreader for the radome 904, to assist in maintaining the radome in position. Radomes are conveniently made from polycarbonate which is susceptible to flexing in use if not supported, which flexing may affect the performance of the antenna. Signals from the control electronics are passed through a connector (not shown) to the antenna feed network. A metallised sheet (not shown) may be placed around the rear of the antenna to contain emissions radiating rearwardly of the antenna, which emissions can cause the formation of unwanted intermodulation products.
In the case of electrical downtilt, the feed network provides varying paths from a feed input to each of the antenna feed probes of the antenna array. The varying paths introduce differences in path length. The phase shifts in the feed paths for the antenna elements have been effected progressively across the antenna array (also known as a phase taper) which have the primary result of effecting downtilt. Typically, a phase taper for an array will produce 10-90° phase difference between antenna elements of an array, which elements are spaced 1/2-3/4 wavelengths apart. The many benefits in the design and installation of such antenna arrays in comparison with mechanical downtilting can easily be envisaged; moreover, the coverage defined is near uniform by reason of the nulls between lobes not being significant.
Alternatively, the feed paths need not be grouped for antenna elements having similar phase shifts, but the power split between tracks of the feedback path can be such that. in addition to the progressive phase change, a progressive amplitude difference for the antenna elements be effected. The effect of changing the amplitude of a feed input for the antenna elements is in many ways similar to the effect of changing the phase of a feed input for a group of elements. since both the amplitude and phase are components of the complex excitations of the radiated signals.
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The present invention relates to antennas. One of the problems which arises during the operation of a linear array antenna with electrical downtilt is that cross-polar radiation currents are generated. These cross-polar radiation currents, if at the same frequency as the operating band of the antenna, interfere with the required gain of the antenna. The present invention provides a solution to cross-polar radiation currents with an antenna assembly comprising first and second apertured ground planes with an antenna probe feed network printed upon a dielectric substrate supported therebetween, the array of radiating elements having different phase input feeds, wherein an outwardly extending ground plane flange extends from one of the apertured ground planes. There is also provided a method of receiving and transmitting signals by means of a layered antenna of this construction.
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TECHNICAL FIELD
This disclosure relates to the field of vehicle drivelines. More particularly, the disclosure pertains to a constant velocity universal joint having a protective shield.
BACKGROUND
FIG. 1 schematically illustrates a rear wheel drive vehicle powertrain with an independent rear suspension. Solid lines indicate shafts capable of transferring torque and power. Engine 10 converts chemical energy in the fuel into mechanical power. Transmission 12 modifies the speed and torque to suit current vehicle requirements. At low vehicle speed, the transmission provides torque multiplication for improved performance. At cruising vehicle speed, the transmission increases speed permitting the engine to run at a fuel efficient operating point. The output of transmission 12 is coupled to the input of differential 14 by rear driveshaft 16 . Two components are coupled when rotating either component by one revolution causes the other component to rotate by one revolution. Differential 14 distributes the power to left rear wheel 18 and right rear wheel 20 via left axle shaft 22 and right axle shaft 24 respectively. Differential 14 changes the direction of rotation by 90 degrees and multiplies the torque by a final drive ratio. Differential 14 provides approximately equal torque to each wheel while permitting slight speed differences as the vehicle turns a corner.
In a four wheel drive vehicle based on the powertrain of FIG. 1 , a transfer case fixed to the transmission divides power between the rear driveshaft 16 and a front driveshaft that directs power to the front wheels via a front differential. In a front wheel drive powertrain, the front differential is typically integrated with the transmission in an assembly called a transaxle. In a four wheel drive vehicle based on a front wheel drive powertrain, a power take-off unit fixed to the transaxle drives a rear driveshaft and a rear drive unit fixed to the rear differential selectively transfers power to the rear differential. Throughout this document, the term transmission should be interpreted to include any transfer case or power take-off unit. Similarly, the term differential should be interpreted to include any rear drive unit.
Engine 10 , transmission 12 , and rear differential 14 are mounted to vehicle structure. Wheels 18 and 20 are supported via a suspension that allows the wheels to move vertically over road bumps while limiting the vertical movement of the vehicle body. The axis of rotation of engine 10 and transmission 12 may be offset slightly from the input axis of differential 14 . Universal joints 26 and 28 accommodate this offset by transmitting torque and power between shafts that rotate about intersecting but not coincident axes. Similarly, universal joints 30 , 32 , 34 , and 36 accommodate the offset between the output axis of differential 14 and the axes of rotation of wheels 18 and 20 even though the axes of rotation of the wheels fluctuates as the wheels absorb road bumps. In some rear wheel drive vehicles, the differential 14 is not mounted directly to the vehicle frame but is instead supported by left and right axles 22 and 24 . This eliminates the need for universal joints 30 and 34 but universal joints 26 and 28 must then accommodate a fluctuating offset between the transmission output axis and the differential input axis.
A variety of types of universal joints are known. In the simplest types of universal joint, although the driving shaft and driven shaft are coupled, the instantaneous speed of the driven shaft differs slightly from the instantaneous speed of the driving shaft as a function of rotational position. Consequently, although the driving shaft may have a constant speed, the driven shaft speed may oscillate at a frequency proportional to the driving shaft speed. Due to the inertia associated with the driven shaft, this results in an oscillating torque level. The oscillating torque level may be perceived by vehicle occupants, especially if the frequency is close to a natural frequency of the driveline. Therefore, universal joints that maintain equal instantaneous speeds between the driving and driven shafts, called Constant Velocity (CV) joints, are desirable. Several types of CV joint mechanisms are known. Among known CV joint types, tripod joints and Rzeppa joints are common in automotive drivelines.
SUMMARY OF THE DISCLOSURE
A constant velocity joint includes a ring, a shaft, a flexible boot, and a protective shield. The ring is adapted for fixation to a flange of a powertrain component such as a transmission. The ring and the shaft are coupled to rotate at the same rotational speed, but their axes are not constrained to be coincident. The flexible boot seals a cavity containing lubricating fluid. The protective shield includes a rigid portion and a flexible portion. The rigid portion, which is fixed to the ring, extends axially over the boot to protect the boot from projectiles and to prevent ballooning. An outer edge of the flexible portion is fixed to the ring while an inner edge of the flexible portion maintains contact with the shaft, preventing projectiles from reaching the flexible boot around the rigid portion. The flexible portion may define a plurality of truncated conical panels with alternating orientation such that the flexible portion deflects accordion fashion to accommodate the non-coincident axes of the ring and shaft. Both the rigid portion and the flexible portion of the protective shield may be formed in multiple circumferential segments for ease of assembly.
A vehicle driveshaft includes a shaft, a ring, a flexible boot, a rigid shield, and a flexible shield. The shaft is adapted for fixation to a differential at one end and is coupled to the ring at the opposite end. The shaft and the ring have non-coincident axes. A flexible boot is fixed to the ring and to the shaft. The rigid shield fixed to the ring extends axially over the flexible boot to protect the boot from projectiles and to prevent ballooning. An outer edge of the flexible shield is fixed to the rigid shield while an inner edge of the flexible shield contacts the shaft. The flexible portion may define a plurality of truncated conical panels with alternating orientation such that the flexible portion deflects accordion fashion to accommodate the non-coincident axes of the ring and shaft. Both the rigid portion and the flexible portion of the protective shield may be formed in multiple circumferential segments for ease of assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a vehicle powertrain.
FIG. 2 is side cross section of a CV joint suitable for use in several locations in the powertrain of FIG. 1 .
FIG. 3 is an end cross section of the CV joint of FIG. 2 .
FIG. 4 is a pictorial view of the CV joint of FIG. 2 .
FIG. 5 is a side cross section of the CV joint of FIG. 2 with a protective shield.
FIG. 6 is a pictorial view of the CV joint of FIG. 2 with a protective shield.
DETAILED DESCRIPTION
Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
FIGS. 2-4 illustrate a Rzeppa-type CV joint suitable for use at 26 , 28 , 30 , 32 , 34 , and/or 36 in FIG. 1 . FIG. 2 is a cross section in the plane defined by the centerlines 50 and 52 of the two sides of the joint. Ring 54 is adapted for fixation to the driveline component such as the transmission output shaft, the wheel, or the differential as described in detail below. Stub shaft 56 is adapted for fixation to driveshaft 16 or to an axle shaft 22 or 24 . Stub shaft 56 may be fixed to the shaft by welding at the circumference of flange 58 , for example. Six concave grooves 60 are formed in ring 54 and six convex grooves 62 are formed in stub shaft 56 . Six balls 64 , each positioned within a concave groove 60 and a convex groove 62 , position stub shaft radially with respect to ring 54 . The balls can roll within the grooves to accommodate the angle between axis 50 and axis 52 . For example, as shown in FIG. 2 , the ball at the top has rolled toward the left of the groove in ring 54 and has rolled toward the right end of the groove in stub shaft 56 . The ball on the bottom has rolled the opposite direction. As either the ring or the stub shaft rotates about its respective axis, the balls force the other member to rotate by an equal amount such that the grooves line up at the ball locations. The balls may be retained by a cage (not shown).
Proper function of the joint requires lubrication, typically in the form of grease. A back plate 66 and a flexible boot 68 seal a cavity to retain the grease and to prevent contaminants from entering. Flexible boot 68 may be a J-shaped boot fixed to front plate 72 which, in turn, is fixed to ring 54 . Boot 68 is made of a flexible material to accommodate the different axes of rotation. During each revolution of the shafts, a particular circumferential portion of the boot changes from the shape shown at the top of FIG. 2 to the shape shown at the bottom of FIG. 2 and then back. In some applications, such as the underside of an off-road vehicle, the joint may be vulnerable to projectiles that may puncture the J-boot. If the grease leaks out or contaminants get in, friction may lead to rapid temperature increase and joint failure.
Another failure mode, called ballooning, occurs when the pressure builds up inside the grease cavity. This may occur, for example, due to friction causing the temperature of the grease and air in the cavity to increase. Centrifugal forces also contribute to internal pressure in the cavity. The increased pressure may cause boot 68 to deform such that the convex surface facing the grease cavity becomes concave. This type of deflection weakens the boot material over time, eventually leading to loss of sealing function and eventual joint failure.
FIG. 3 is a cross section taken through the plane defined by the six balls 64 . FIG. 4 is a pictorial view of the joint. Ring 54 defines six holes 70 that are used to fix the ring to the component, such as the transmission, differential, or wheel. Specifically, six bolts are inserted through the holes 70 , from the side with the J-boot, into threaded holes in a flange of the component. Washers may be inserted to distribute the compressive force from the bolt head across the face of the front plate 72 . In some cases, it may be necessary to rotate the shaft after inserting some of the bolts in order to be able to reach the remaining bolts with an appropriate tool. The shaft may be welded to the stub shaft 54 prior to positioning the shaft assembly into the vehicle.
FIGS. 5 and 6 show the CV joint of FIGS. 2-4 with a protective shield. FIG. 5 is a cross section in the same plane as FIG. 2 . The protective shield includes a rigid portion 74 and a flexible portion 76 . The rigid portion 74 is fixed to the ring. For example, the rigid portion may be fixed to the ring by the same bolts 78 that fix the ring to the driveline component. A flange of the rigid portion may be compressed between the washer 80 and the front plate. The rigid portion 74 also constrains boot 68 from ballooning outward. The rigid portion protects the flexible J-boot from damage. The flexible portion seals off the gap between the rigid portion and the shaft, preventing any projectiles from reaching the J-boot and potentially rupturing it. In order to accommodate the non-coincident axes of rotation, an inner edge of the flexible portion must be capable of moving to a position not concentric with an outer edge. This may be accomplished, for example, by forming the flexible portion with an accordion shape having a number of truncated conical panels 77 with alternating orientation. Unlike the flexible J-boot, however, the flexible portion of the protective shield does not need to form a seal against the shaft. If a projectile, such as a rock, creates a small hole in the flexible portion, the universal joint will continue to function properly.
FIG. 6 is a pictorial view of the CV joint with protective shield 74 and 76 . FIG. 6 also shows the six bolts 78 and the washers 80 used to fasten ring 54 to a component flange. Note that both the rigid portion 74 and the flexible portion 76 of the shield may be formed from multiple circumferential segments 82 which collectively surround the circumference of the J-boot. Each circumferential portion can be fastened to the CV joint separately.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications.
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A constant velocity (CV) joint includes a shield to protect a J-boot from damage due to projectiles such as stones and to prevent ballooning. A rigid portion of the shield is fixed to a ring, which is adapted for fixation to a powertrain component such as a transmission. A flexible portion of the shield prevents projectiles from entering through the opening created by non-coincident axes of the shaft and ring. The flexible portion has a number of truncated conical panels with alternating orientation that accommodate the variable size opening by flexing in an accordion-like fashion.
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RELATED APPLICATIONS
The present application is related to U.S. Provisional Patent Application Ser. No. 61/540,473, filed on Sep. 28, 2011 pursuant to 35 USC 119 and is a continuation in part of U.S. patent application Ser. No. 12/763,863 filed on Apr. 20, 2011 pursuant to 35 USC 120, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to multi-modal medical imaging, and more specifically to the use of combined magnetic resonance-single photon or positron emission tomography of the human breast for diagnosis of cancer and evaluation of treatment.
BACKGROUND
Although mammography is very sensitive in detecting early breast cancer, it does not work well in women who have dense breasts, breast implants, or scar tissues. Alternatively, magnetic resonance imaging (MRI) has proven to the most sensitive imaging modality in delineating tumor extent and detecting multifocal or multicentric diseases. Many studies indicate that preoperative MRI is useful in local staging for surgical planning, especially for patients with lobular cancer. However, the variable specificity of MRI can lead to unnecessary biopsies and over-treatment.
Scintimammography (SMM) is a single photon breast imaging technique used to detect cancer cells in patients who have had abnormal mammograms or dense breast tissue. In this test, a patient will receive an injection of technetium 99 sestamibi, a gamma-ray emitter which is preferably taken up by cancer cells. The breast is then usually compressed and imaged by a gamma camera. SMM can potentially supplement MRI for improving the diagnostic specificity in breast cancer imaging.
The combination of MRI and SMM has great clinical potential for improving specificity through SMM while maintaining the high sensitivity offered by MRI. However, interference between the MRI and SMM components presents a significant challenge to the design of any combined system. This interference can lead to major artifacts and image degradation in both modalities. The primary concerns are electromagnetic interference and the effects of the B 0 magnetic field of the MRI scanner on the SMM detectors. Traditional gamma-ray detectors based on scintillators coupled to photomultiplier tubes do not function properly within high magnetic fields. Instead, MR-compatible cadmium-zinc-telluride (CZT) semiconductor-based radiation detectors may be utilized. Such detectors, however, must be enclosed in RF shielding to prevent electromagnetic interference between the MRI and SMM systems. Furthermore, sufficient gamma-ray shielding is required to prevent the detection of uncollimated radiation. Both of these shielding layers have the potential to adversely affect MR imaging, particularly when they are placed within the RF coil.
BRIEF SUMMARY OF THE INVENTION
To solve these and other long-felt needs in the art, an apparatus and method for MRI-compatible nuclear breast cancer imaging is here disclosed. In its primary aspect, the illustrated embodiments of the invention include a MR breast RF coil combined with planar scintigraphic or PET detectors to enable one to perform coregistered breast MRI and nuclear imaging. This technique has been termed magnetic resonance-scintimammography (MRSMM). If PET detectors are used then it is called positron emission mammography (PEM). In case of the positron emission version of the same device single photon detectors such as CZT are replaced by MR compatible positron emission coincidence detectors. When dedicated positron emission tomography is used for breast imaging it is called positron emission mammography (PEM). The RF coil and compression device described in this application is equally applicable to SMM as well as PEM with appropriate replacement of the detectors.
One embodiment of the invention, the MR-SSM or MR-PEM apparatus, comprises an MRI imaging system having an RF array coil consisting of two parallel circular loops, each mounted on an acrylic end plate with the material normally found within MRI loops removed to allow for insertion of the breast. The ea of separation between the end plates allows for the insertion of opposing CZT detector modules with parallel-hole collimators, integrated with breast compression paddles. The opposing CZT detector modules are part of a nuclear imaging system. A control device allows for accurate adjustment of the compression of the breast by the paddles under observation. In case of PEM the CZT detectors are replaced by the PEM detectors while the remainder being the same.
In another embodiment the invention comprises a method of use for the apparatus. The RF coil is positioned within an MRI bore such that it generates a B 1 magnetic field parallel to the (vertical) y-axis. The patient lies prone on top of the assembly with the breast to be imaged inside the RF array coil, and is injected with the appropriate radiopharmaceutical without being moved from the RF coil. After a short period of time, the CZT detector module integrated with breast compression paddles are brought towards the breast in question and the breast is compressed lightly using a selectively controlled compression device. The MR/SMM or MR/PEM assembly, including the RF coil, can be adjusted along the y-direction so that the volume of interest within the breast can be centered within the RF coil and positioned within the field of view of the CZT detectors. The assembly may rotate around the y-axis around the breast, and MR images may be used to determine the optimum orientation of the CZT detectors.
In particular, the illustrated embodiments include an apparatus for combined magnetic resonance (MR) and nuclear imaging of human breast for cancer diagnosis comprising an MRI system including an MR breast RF coil combined with a nuclear imaging system having a detector disposed or disposable within the MR breast RF coil arranged and configured for the performance of simultaneous or sequential coregistered breast MRI and nuclear imaging, and a selectively controlled compression mechanism for lightly compressing the breast being imaged in which the compression mechanism is integrated with the MR breast RF coil.
The detector of the nuclear imaging system includes a scintigraphic single photon imager or coincidence based positron emission tomography (PET) detector.
The mechanism for lightly compressing the breast being imaged includes a pair of opposing compression paddles and where the detector of the nuclear imaging system comprises a pair of opposing rectangular nuclear detectors placed behind the compression paddles in either side away from the breast, which is placed between the compression paddles.
The detector of the scintigraphic nuclear imaging system (SMM) includes a pair of opposing cadmium-zinc-telluride (CZT) detectors each encapsulated in RF and gamma-ray shielding and disposed within the MR breast RF coil. For PEM appropriate MR compatible positron coincidence detection detectors are used.
The MR breast RF coil includes a pair of opposing RF coils aligned on a common axis and separated by an open space, and where the detector of the nuclear imaging system comprises a pair of opposing rectangular nuclear detectors oriented on a common axis perpendicular to the common axis of the pair of opposing RF coils.
In one embodiment the opposing rectangular nuclear detectors are permanently disposed into the open space between the pair of opposing RF coils.
In another embodiment the opposing rectangular nuclear detectors are movable to be temporarily disposed into the open space between the pair of opposing RF coil's when a nuclear image is being taken.
The nuclear detector is gamma shielded and RF shielded and further comprising a collimator disposed between the breast and the detector for collimating nuclear radiation from the breast to the detector.
The illustrated embodiments also encompass a method for use in diagnostic breast imaging of a subject including the steps of positioning the subject in a prone position into a breast MR RF coil in an MRI system to image a selected breast, performing a dynamic contrast enhanced MRI on the selected breast, if the selected breast shows any increased signal enhancement, then injecting the subject with a selected radiopharmaceutical without moving her from the MRI imaged position in the MR RF coil, and employing a nuclear detector, inside the MR RF coil, to image the selected breast while applying light breast compression to the selected breast in a predetermined direction during imaging.
The method is also performed on the other one of the breasts other than the selected breast.
The method employs a nuclear detector, inside the MR RF coil, to image the selected breast comprises using MR-single photon scintigraphy or MR-PEM for imaging.
The illustrated embodiments of the invention are also defined as a method use in diagnostic imaging of a human breast for cancer diagnosis including the steps of performing scintimammography (SMM) or positron emission mammography (PEM), and performing MRI to improve the diagnostic specificity and to result in both high sensitivity from MRI and high specificity from SMM or PEM by using a dual-modality system with an ntegrated radio frequency (RF) coil and radiation detector under a strong magnetic field without significant mutual interference.
The combination of performing scintimammography (SMM) or positron emission mammography (PEM) and performing MRI uses a unilateral breast array MR RF coil specialized for combined MRI and nuclear imaging.
The combination of performing scintimammography (SMM) or positron emission mammography (PEM) and performing MRI includes simultaneously acquiring MR and SMM or PEM images of a breast using an integrated MR-SMM or MR-PEM system as appropriate.
The illustrated embodiments include a composite data image recorded on a tangible medium produced by performing scintimammography (SMM) or positron emission mammography (PEM) and by performing MRI to improve the diagnostic specificity and to result in both high sensitivity from MRI and high specificity from SMM or PEM by using a dual-modality system with an integrated radio frequency (RF) coil and radiation detector under a strong magnetic field without significant mutual interference in which data image is a composite of a coregistered MRI image and a nuclear image. The composite data in age is generated by conventional overlay imaging software well known to the art for combining and coregistering two data fields, one for the MRI and the other from SMM or PEM.
While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC 112, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC 112 are to be accorded full statutory equivalents under 35 USC 112. The disclosure can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
The specification contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 a is a simplified diagram of the material elements internal to the MRSMM assembly.
FIG. 1 b is a three dimensional rendering of a model of the RF coil and RF shielded detector blocks for use in a simulation program, which blocks are located 10 mm from a brick-shaped phantom.
FIG. 1 c is a top down view of are experimental setup for testing RF and gamma-ray shielding in the RF coil.
FIG. 1 d is a top down view of a gamma-ray shielding box on the left and an additional RF shielding on the right of the photograph.
FIG. 2 a - 2 d is a diagram of breast compression at an uncompressed state, 0°, 45°, and 90° compression angles respectively.
FIGS. 3 a - 3 f are colored two dimensional data graphs of the simulated RMS modulus B 1 field distribution (left column) and RMS modulus E 1 electric field distribution (right column) generated by the RF array coil tuned to 127 MHz without the phantom conductive copper blocks ( FIGS. 3 a , 3 b ), the coil shifted to 138 MHz with the introduction of the phantom conductive blocks ( FIGS. 3 c , 3 d ), and coil with the conductive blocks re-tuned to 127 MHz ( FIGS. 3 e , 3 f ). The phantom copper blocks were hollow brick shaped Lucite phantoms filled with a copper sulfate solution. A shift in the electric field intensity around discrete components such as capacitors accounts for the asymmetry in FIG. 3 b . The B 1 field maps were normalized to 2.37×10 −10 A/m and the electric field maps ere normalized to 2.59×10 −8 V/m.
FIGS. 4 a - 4 f are colored two dimensional data graphs of the simulated B 1 field distribution ( FIGS. 4 a , 4 b ), E 1 electric field distribution ( FIGS. 4 c , 4 d ) and SAR distribution ( FIGS. 4 e , 4 f ) generated by the RF array coil tuned to 127 MHz without the phantom conductive copper blocks (left column) and with the phantom copper blocks (right column). The B 1 maps were normalized to 2.37×10 −10 A/m, the electric field maps were normalized to 2.59×10 −8 V/m and the SAR maps were normalized to 5.48×10 −20 mW/g.
FIGS. 5 a - 5 f are colored graphs of the frequency spectra (impedance in Ω versus frequency in MHz) of the RF array coil with the RF shielding ( FIGS. 5 a , 5 b ), gamma-ray shielding ( FIGS. 5 c , 5 d ) and both shielding ( FIGS. 5 e , 5 f ) placed 125 mm (black solid line), 85 mm (black dotted line), 52 mm (black dashed line), 42 mm (gray dashed line), 36 mm (gray dotted line), 26 mm (gray solid line), and 26 mm with re-tuning (red line) from the isocenter of the coil.
FIGS. 6 a - 1 - 6 d - 4 are grayscale data MR images of the brick phantom with no shielding ( FIGS. 6 a - 1 to 6 a 4 ), RF shielding ( FIGS. 6 b - 1 to 6 b 4 ), gamma-ray shielding ( FIGS. 6 c - 1 to 6 c - 4 ) and both shielding ( FIGS. 6 d - 1 to 6 d - 4 ) placed 10 mm from the phantom within the RF coil. All modulus and phase images were each scaled to identical contrast levels.
FIG. 7 are grayscale data MR and SMM images from a top detector (left ages of each column) and bottom detector (right images of each column) of a breast phantom with three different simulated compression angles for three different background configurations. Each SMM image interpolated was normalized to the maximum value of all the images. The red box denotes the region of interest (ROI) used to measure the radioactive counts.
The disclosure and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the embodiments defined in the claims. It is expressly understood that the embodiments as defined by the claims may be broader than the illustrated embodiments described below.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention is the MRSSM apparatus 10 . One preferable embodiment of apparatus 10 is optimized for a 3T magnetic resonance imaging (MRI). However, it is to be understood that any conventional MRI field specification or MRI imaging system may be employed, when modified as disclosed below. The geometry of the RF array coil 12 of the MRI system includes two parallel circular loops 12 a and 12 b each 15 cm in diameter and separated by 6.5 cm as diagrammatically shown in FIG. 1 a . In the illustrated embodiment as an example only, each loop 12 a and 12 b is etched on FR4 laminate board using copper strips of 0.0341 mm thickness, and mounted on an acrylic plate with the material within the loops removed to allow for insertion of the breast 14 . The separation between the end plates of the coils 12 a and 12 b allows for insertion of CZT detector modules 16 through the side of the RF coil 12 . MR compatible CZT detector modules 16 have been developed with the consultation of the inventors by Gamma Medica Inc. Each coil loop 12 a , 12 b also contained fully integrated components that are tuned to 127 MHz (the Larmor frequency at 3T) and matched to 50Ω. A collimator 18 is provided inwardly of each CZT detector module 16 adjacent to paddles 20 used for compression of breast 14 . The mechanism for selectively controlling the positioning and force applied to paddles 20 may assume any one of many different conventional configurations well known to the art. FIG. 1 b is a rendering of a simulation model of a breast phantom 14 a between detector modules 16 and between coils 12 a , 12 b , showing the x axis 28 , y axis 24 and z axis 26 .
Mutual coupling between the coils 12 a , 12 b cannot be eliminated by geometrical overlapping or connecting to low noise amplifiers alone. Thus to remove mutual coupling, two methods are simultaneously used: Inductive decoupling, in which air inductors (not shown) are connected to each coil loop 12 a , 12 b are crossed over, and integration of low noise amplifiers (not shown) with a low input impedance (below 20Ω). Since the RF array coil 12 operates only as a receiver, the above combined detuning method using active and the passive detuning circuits added to each loop 12 a , 12 b was utilized to decouple the array coil 12 during transmission of high power RF energy.
For SMM imaging, each CZT-based radiation detector module 16 (Gamma Medica, Inc., Northridge, USA) including a 50.8×50.8×5 mm of CZT crystal coupled to 1024 (32×3) detector elements is mounted in a 17×6.5×6 mm box 22 . The walls of box 22 are made of a lead composite for gamma-ray radiation shielding. The MR compatibility of the lead composite when placed outside of an RF coil 12 has been demonstrated in the prior art. The lead composite of the walls of box 22 is segmented on the edges to suppress the flow of eddy currents caused by gradient switching in the MRI, which may prevent significant image artifacts in MRI such as image distortion. The box 22 of FIG. 1 d is experimentally tested for RF and gamma-ray shielding using the experimental jig 30 of FIG. 1 c.
For breast imaging, two opposing CZT detector nodules 16 with parallel-hole collimators 18 are integrated with breast compression paddles 20 and positioned between the acrylic end plates (not shown) of the RF coil 12 . A control knob (not shown) is mechanically coupled to paddles 20 to allow for accurate adjustment of the compression under observation by the operator. Although breast compression is not required for MR imaging, it is of benefit to SMM since this modality's spatial resolution decreases as the distance of a human breast 14 from the collimator 18 increases. While the use of opposing detectors 16 can compensate for this resolution loss on the periphery, compression is needed to reduce the distance from the center of the breast 14 to each collimator 18 .
The RF coil 12 is positioned within the MRI bore (not shown) such that it generates a B 1 magnetic field parallel to the y-axis. The MRSMM assembly 10 including the RF coil 12 may be adjusted along the vertical y-direction so that the volume of interest within the breast 14 can be centered within the RF coil 12 and positioned within the field-of-view (FOV) of the CZT detectors 16 . Furthermore, the assembly 10 may rotate about the y-axis 24 around the breast 14 . This feature is important for SMM imaging when distinguishing multiple lesions. Unlike three-dimensional (3D) tomography, SMM only acquires two dimensional (2D) projection images. Thus in the case of two lesions, one orientation provides maximum separation while others make it difficult to distinguish. An immediate benefit of combined MRSMM imaging is that the MR images can be used to determine the optimum orientation of the CZT detectors 16 .
The RF coil 12 for MRSMM imaging should provide high signal-to-noise (SNR) and field homogeneity in the presence of the CZT detector modules 16 . However, these modules 16 , particularly the RF shielding, may distort the EM field generated by the RF coil 12 . In a prior art study of this distortion, the system configuration allowed for the RF shielding to be placed up to 6 cm away from the RF coil. Therefore, the B 1 field and parameters, such as the quality (Q) factor, resonance frequency, and impedance of the RF coil were not significantly affected. In the illustrated embodiments of the invention, the CZT detector modules 16 are positioned directly between the end plates of the RF coil 12 . Due to the close proximity of these components, the effect of the RF shielding on the RF coil 12 requires investigation. To investigate this issue, the RF coil 12 and RF shielding were modeled using a simulation program (SEMCAD X Ver, 14.2.1, Schmid & Partner Engineering AG, Zurich Switzerland) to assess the EM field change, resonance frequency variation, and SAR distribution when the detector modules 16 were positioned through the side opening of the RF coil 12 . Specific absorption rate (SAR) is a measure of the rate at which energy is absorbed by the body when exposed to a radio frequency (RF) electromagnetic field; although, it can also refer to absorption of other forms of energy by tissue, including ultrasound. It is defined as the power absorbed per mass of tissue and has units of watts per kilogram (W/kg). SAR is usually averaged either over the whole body, or over a small sample volume (typically 1 g or 10 g of tissue). The value cited is typically then the maximum level measured in the body part studied over the stated volume or mass.
While the actual RF shielding consists of copper mesh covering the detector modules 16 , it was modeled as perfect conductive blocks with electric conductivity a=5.96×10 7 S/m in the simulation. The SAR map was calculated as:
SAR=(σ/2ρ)| E| 2
Where ρ is the mass density of the object and E is the induced electric field vector which was calculated using the finite difference time domain method. To simulate a compressed breast 14 , a 11.5×11.6×4.5 cm brick-shaped dielectric phantom 14 a was used with the following parameters: relative permittivity (∈ r )=32.6, electric conductivity (σ)=0.61 S/m and density=1000 kg/m 3 .
Changes in the Q-factor, resonance frequency, and impedance when the CZT detectors 16 are positioned within the system may be evaluated using the RF array coil 12 . These parameters may be measured with the CZT detector modules 16 placed at various distances from the isocenter of the RF coil 12 . The modules 16 may be tested without RF and gamma-ray shielding, with RF shielding only, with gamma-ray shielding only, and with both RF and gamma-ray shielding. All parameters may be measured without loading the RF coil 12 .
A brick-shaped phantom 14 a with identical dimensions to the simulation was used for MRI tests. It was filled with a solution of 4.0 g/L CuSO 4 .5H 2 O, 10 g/L NaCl, and distilled water. The phantom was positioned at the isocenter of the RF coil 12 and the detector modules 16 positioned 10 cm away from the phantom 14 a . The setup was placed within a 3T Philips Achieva system (Philips medical Systems, Netherlands). Coronal MR images of the middle of the phantom 14 a were acquired using a gradient-echo sequence with the parameters: FOV=120×120 mm, matrix size=256×256, echo time (TE)=5 ms, repetition time (TR)=30 ms, flip angle=60°, slice thickness=5 mm, and number of signal averages (NSA)=4, MRI data was acquired for detector modules 16 without RF and gamma-ray shielding, with RF shielding only, with gamma-ray shielding only, and with both RF and gamma-ray shielding. For each configuration, MR images were acquired without and with 2 nd and 3 rd order shimming to assess correction of any B 0 field distortions caused by the shielding.
From the acquired MRI, the signal-to-noise ratio (SNR) was calculated as [(signal average−noise average)/(noise standard deviation)]. To measure the phantom signal, a rectangular region of interest was drawn over the central 80% of the phantom image. To calculate the noise, the standard deviation was measured from the background.
To demonstrate operation of the integrated MRSMM system 10 , simultaneous MR and SIMM imaging of a breast phantom 14 a were performed. A hollow, oval-shaped acrylic cylinder with a length of 80 mm, width of 68 mm, and height of 120 mm was used to simulate a compressed breast 14 . Two vials 32 of 10 mm in diameter each and separated by 15 mm were used to simulate breast lesions. The phantom 14 a was placed at the center of the RF coil 12 within a 3T MRI system. The two vials 32 simulating lesions were placed at the center of the phantom 14 a . Three different orientations for the vials 32 were tested (0°, 45°, 90° simulating three different angles of breast compression as diagrammatically shown in FIGS. 2 a - 2 d . Three different data sets may acquired, each testing the three different orientations for the vials 32 . For all data sets, the vials 32 were each filled with a solution of 4 mM CuSO 4 and 60 μCi/ml of 99m Tc sestimibi (Cardiolite; Cardinal Health, Dublin, USA) as a pharmaceutical agent used in nuclear medicine imaging. For the first data set, a hollow breast phantom 14 a “background” was left empty. In the second data set, the background was filled with a 10 mM CuSO4 solution. In the third data set, the background was filled with a solution containing both 10 mM CuSO 4 and 1 μCi/mL of 99m Tc sestimibi. For each vial orientation, a coronal MR image of the middle of the phantom 14 a was acquired using a 20 fast-spin-echo sequence with the following parameters: TR=1.5 s, TE=80 ms, FOV=150×150 mm, matrix=512×512, slice thickness=5 mm, NSA=4. Concurrent to the MRI acquisition, nuclear radiation counts were recorded from the CZT detector modules 16 for 10 minutes. The spectrum for each detector modules 16 was then windowed about the 140 keV photopeak (±5%) and the resulting SMM images were adjusted for radioactive decay and corrected for inherent nonuniform detector sensitivity using the image of a flood-field phantom. For the 0° orientation, a ROI was drawn about one of the vials 32 in each of the SMM images. The number of radiation counts within the ROI was then computed. From the MR image, the distance from the vials 32 to the detector module 16 through the background was measured. This information was then used to correct for attenuation by the water background in the second and third data sets. In the SMM images of the third data set, a second ROI containing only the background along with geometrical measurements from the MR images was used to determine the background activity concentration. This information was used to remove the background contribution to the counts measured within the first ROI prior to attenuation correction. After this background correction, attenuation correction was then performed to yield the corrected activity of only the vial 32 .
In simulation studies, the RF array coil 12 tuned exactly to the target frequency (127 MHz) without the presence of the RF-shielded modules 16 was observed to have generated a homogeneous B 1 field in the region between the coil loops 12 a , 12 b as shown in FIGS. 3 a and 4 a . With the addition of the conducting blocks, the resonance frequency of RF coil 12 shifted to 138.2 MHz. Nevertheless, at this shifted frequency, the conducting blocks did not produce any B 1 field distortion within the phantom region as shown in FIGS. 3 c and 4 d . In contrast, the root mean square (RMS) E 1 electric field sharply increased near the surface of the conducting blocks as shown in FIGS. 3 d and 4 e . After re-tuning the RF coil 12 back to the target frequency with the conductive blocks present, the B 1 field within the phantom 14 a remained uniform while its intensity slightly increased compared to the field generated by the RF coil 12 without the conducting blocks. The RMS E 1 electric field intensity on the surface of the phantom 14 a remained higher than the other areas due to electric charges concentrated on the surface of phantom conductive copper blocks. As a result, a high SAR was localized on the surface of the phantom 14 a as shown in FIG. 4 f.
The Q-factors and impedances for each of the two circular loops 12 a , 12 b of the RF array coil 12 may be experimentally measured without the presence of any shielding. In one embodiment, Q-factor and impedance of the top loop 12 a was 118.6 and 251.6Ω respectively, while the measurements for the bottom loop 12 b were 116.8 and 247.0Ω. When the RF-shielded modules 16 (without gamma-ray shielding) were placed 10 mm away from the phantom 14 a (26 mm from the isocenter of the RF coil 12 ), the Q-factor and impedance of both coil loops 12 a , 12 b decreased 27.1% and 46.3% respectively. The resonance frequency also shifted up about 6.5 MHz from the target frequency, which was a smaller change than the one observed in the simulation. Unlike the simulation results, the resonance frequency spectrum split into two peaks when the RF-shielded modules 16 were positioned closer than 10 mm from the phantom 14 a as shown in FIG. 5 a . However, when the RF coil 12 was returned to the target frequency, the frequency spectrum returned to a single peak, while the reduced Q-factor remained. When the gamma-ray shielded modules 16 were moved into the space between the RF coil loops 12 , the frequency remained constant, but the Q-factor dropped. This finding is consistent with the previous studies. When both the gamma-ray and RF shielding were positioned within the RF coil 12 , the resonance frequencies shifted up about 7 MHz while the Q-dropped even lower. When the RF coil 12 was re-tuned to the target frequency, the Q-factor remained low, but the splitting in the frequency spectrum was again resolved. A summary of these measurements are shown below in Table 1.
TABLE 1
Average values of the parameters of the two circular loops of the RF array
coil. The frequency and Q-factors were measured without loading the
coil. The SNR was calculated from the MR images of the brick phantom.
Frequency
Q-factor
(MHz)
Q-factor
after re-tuning
SNR
No shielding
127.0
117.5
—
301.1
RF shielding
132.5
86.1
87.9
231.3
Gamma-ray shielding
127.0
82.0
—
219.8
RF and gamma-ray
134.0
68.6
61.3
185.6
shielding
MR images of the brick phantom are shown in FIG. 6 . A similar modulus image for all shielding configurations indicates that the B1 field with the phantom region was not significantly affected by the presence of the RF or gamma-ray shielding, as predicted by the simulation studies. With linear (1st) order shimming, the phase images ere also similar, except for the case with only the gamma-ray shielding. However, high (2nd and 3rd) order shimming resulted in similar and more uniform phase images for all configurations. The SNRs calculated from the modulus images acquired with high order shimming are listed in Table 1. These values parallel the changes in the Q-factor for the different shielding configurations.
MR and SMM images of the compressed breast phantom are shown in FIG. 7 . The number of radioactive counts measured within an ROI encompassing one of the vials is listed in Table 2 below. As anticipated, the two vials 32 are distinguishable in the SMM images for the 0° and 45° orientations, but indistinguishable for the 90° orientation, thus demonstrating the importance of using the proper compression angle. The image intensity and measured activity of the vials 32 decrease as water is added to the background due to attenuation of the gamma-rays. For the 45° orientation with water background, the two vials 32 have slightly different intensities due to the different attenuating distances through the water from each vial 32 to the detector 16 . The measured radioactivity within the ROI increases when radioactivity is added to the background since both the vial 32 and the background contribute to the counts measured within the ROI. Attenuation correction of the measured counts from the water background configuration was able to restore the original (no background) counts to within 2%. Subtraction of the background activity within the ROI followed by attenuation correction was able to restore the counts from the active background configuration to within 1%.
TABLE 2
Radioactive counts within the ROI of FIG. 7 for the different
background configurations. MRI-based attenuation correction (AC) and
background correction (BC) were used to restore the original
(no background) counts from the vial.
no
water
active
background
background
background
raw counts
59056
36175
65110
with AC
—
60242
—
with BC
—
—
35845
with AC and
—
—
59692
BC
The results of simulation and experimental measurements demonstrate the effects of placing CZT detector modules 16 with RF and gamma-ray shielding into an RF array coil 12 for MRSMM imaging. The RF shielding introduces a shift in the resonance frequency and an increase in the E 1 electric field and SAR at the periphery of the test phantom 14 a . The gamma-ray shielding introduces inhomogeneity in the B 0 field. Both shielding layers do not distort the distribution of the B 1 field in the region between the coil loops 12 a , 12 b , but do result in a decrease in the Q-factor of the RF coil 12 and the SNR of the MR images.
To avoid these adverse effects, MR and SMM imaging may be performed sequentially, where the RF coil 12 is operated without the presence of the (shielded) CZT detector modules 16 . However, if simultaneous imaging is performed, various techniques may be utilized to reduce these adverse effects. To avoid manually re-tuning the RF coil 12 whenever the CZT detector modules 16 are moved within the RF coil 12 , an auto-tuning method using varicap diodes may be utilized. To reduce SAR deposition, lower flip angles, shorter echo train lengths, increased inter-echo spacing, and/or longer TR values may be utilized. Similarly, rapid acquisition with relaxation enhancement (RARE) and variable-rate selective excitation (VERSE) methods may be utilized to improve MR image quality without exceeding SAR limits. The RF array coil 12 may also be adapted for use with parallel imaging techniques, which can decrease RF exposure, by reducing the number of phase-encoding steps. As previously demonstrated, distortion of the B 0 field by the gamma-ray shielded may be corrected through high order shimming. Finally, the drop in image SNR may be compensated by additional signal averaging at the expense of imaging time.
Despite a reduced SNR, the breast phantom experiment demonstrates that accurate MR images ay still be obtained with simultaneous MRSMM imaging.
Furthermore, the MR images were used to measure the geometry of the phantom 14 a to facilitate attenuation and background correction of the radioactive counts within the ROI of the SMM images. In more complex objects, such as the human body, segmentation of the MR images into different tissue types with their corresponding attenuation coefficients and uptake values may be utilized for such corrections. This may enable accurate quantification of radiotracer uptake by suspicious lesions, which may be of clinical value.
In addition to attenuation and background corrections, combined MR and SMM imaging has several other advantages Co-registered anatomical MR images provide a reference for the SMM images, allowing for improved localization. The higher spatial resolution MR images can be utilized to improve the spatial resolution of gamma ray images through post-processing techniques such as the maximization of mutual information. Simultaneous imaging enables the use of both MRI contrast agents and radiotracers to investigate multiple biological processes at the same time.
An additional advantage of simultaneous acquisition is reduction in imaging time by eliminating the need for two separate scans. This is beneficial in a clinical setting, where scheduling, patient convenience, and cost management are significant factors. The rationale for combining MRI with gamma-ray imaging is well understood in the art.
Many alteration and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiments have been set forth for the purpose of example and that they should not be taken as limiting the invention as defined by the following invention and its various embodiments.
The words used in this specification to describe the invention and its, various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use in must be understood as being generic to all possible meanings supported by the specification and by the word itself.
The definitions of the words or elements of the following invention and its various embodiments are, therefore, defined in this specification to include not only the combination of elements which are literally set forth but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the invention and its various embodiments below or that a single element may be substituted for two or more elements in a claim.
Insubstantial changes from the claimed subject matter viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the invention and its various embodiments. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements.
The invention and its various embodiments are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the invention.
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An apparatus combines magnetic resonance (MR) and nuclear imaging of human breast for cancer diagnosis. An MRI system including an MR breast RF coil is combined with a nuclear imaging system having a detector disposed or disposable within the MR breast RF coil arranged and configured for the performance of simultaneous or sequential coregistered breast MRI and nuclear imaging. A selectively controlled compression mechanism for lightly compresses the breast being imaged. The remotely controlled compression mechanism is integrated with the MR breast RF coil.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the present invention relate to computer work stations and to systems for voice messaging that otherwise serve as computer work station input devices.
2. Background of the Invention
As an introduction to problems solved by the present invention, consider the conventional computer work station operated by a skilled operator. The user operates such a work station by orienting his or her hand in relation to an input device such as a keyboard, mouse, touch pad, or digitizing pad. The user's gaze is directed toward a computer monitor that displays text and graphics for guiding the user further. While the user is concentrating on what is shown on the display, the user maintains his or her hand poised and positioned for further input without the inconvenience of having to direct his or her gaze toward his or her hand to reorient it. During concentration, the flow of ideas occurring to the user may be interrupted by an idea unrelated to operation of the computer system.
Conventional computer operating systems provide means for entering a typed note of the idea for further reference at another time. However, prior to entry of such a typed note, the computer monitor display is necessarily changed to show a context in which the typed note is entered and edited. Such a change in the display upsets the visual context that supported the original work prior to interruption. Returning to the original work display image may leave the user without memory of the position or content of the display which was the subject of prior concentration. Consequently, there is a loss of productivity associated with typing a note.
Other manual ways of recording the idea result in physical as well as visual disorientation for the user. Use of a nearby pencil and paper will require movement of the user's hand away from a home position on the keyboard, mouse, touch pad, or digitizing pad. A home position is a position of the user's hand relative to a home surface that provides tactile feedback. Keyboards with tactile feedback are conventionally arranged with keys for "F" and "J" identified, for example, by a different sculpture or a raised bump. Such features distinguish these keys from other keys and so identify a home position for the user's index fingers. Other input devices have home surfaces, too. Operation of a keyboard, as well as other input devices, usually requires directing the gaze toward the input device as the user's hand is placed to recognize the home surface. Thus, time is required to overcome the physical disorientation that precedes returning to a home position. Once in position, returning to the memory of the original work will consume additional time.
Time spent away from the original work raises the cost of the work. Beyond a mere lack of convenience is the risk that an analysis associated with the original work may be incomplete or forgotten. And, if the idea that is to be noted is not noted promptly, this idea may be lost as well.
In view of the problems described above and related problems that consequently become apparent to those skilled in the applicable arts, the need remains in computer work stations for messaging systems that avoid visual interruption and physical disorientation while recording ideas possibly unrelated to computer system operation.
SUMMARY OF THE INVENTION
Accordingly, a work station in one embodiment of the present invention includes a computer system and an input system. The input system controls operation of the computer system. The input system has a home surface that provides tactile feedback to the user who, in response to the feedback, maintains her hand near the home surface during operation of the input system by her hand. The input system includes a recorder that records speech by the user and a switch that starts the recorder. The switch is operated by the user's hand while the user maintains orientation of the user's hand near the home surface.
According to a first aspect of the operation of such a work station, the user avoids visual interruption and physical disorientation while recording speech possibly unrelated to computer system operation.
According to another aspect, recording an idea using speech does not require departing from the visual and physiological context of the work on screen. The act of returning to the original work is less likely to result in loss of the original analysis or train of thought. Consequently, productivity improves.
These and other embodiments, aspects, advantages, and features of the present invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art by reference to the following description of the invention and referenced drawings or by practice of the invention. The aspects, advantages, and features of the invention are realized and attained by means of the instrumentalities, procedures, and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a work station that illustrates a few embodiments of the present invention.
FIG. 2 is a top view of the mouse pad shown in FIG. 1.
FIG. 3 is a top view of the wrist rest shown in FIG. 1.
FIG. 4 is a top view of the keyboard shown in FIG. 1.
FIG. 5 is a perspective view of the mouse shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view of a work station that illustrates several embodiments of the present invention. Work station 10 includes computer 12, voice messaging keyboard 20, voice messaging wrist rest 22, voice messaging mouse 24, voice messaging mouse pad 26, and table 28. Ordinarily one work station component having voice messaging capability would be sufficient; however, work station 10 is illustrated with four such components (20, 22, 24, and 26) for ease of description.
Computer 12 and table 28 are of conventional construction and function. Computer 12 provides display 14 by operation of its conventional operating system and repertoire of conventional application programs. Such programs conventionally provide overlapping display regions in which the context of data entry and control is identified to one particular task. Several tasks may be controllable by user input as indicated by the conventional background dialog box 16 and the conventional foreground dialog box 18. Dialog boxes 16 and 18 represent generally the visually sophisticated computing environment in which the ordinary user works.
A user would ordinarily sit in front of table 28 and place his/her right hand in a conventional manner either on keyboard 20, resting the base of the hand on wrist rest 22, or place the right hand on mouse 24. The left hand would be placed in a conventional manner on keyboard 20, resting the base of it on wrist rest 22. Prior to operation the user would find the home surface under each hand and throughout use, attempt to maintain each hand near the respective home surface either touching on it, hovering over it, or stretching within a vicinity of the home surface that permits quick and accurate return to the home surface without visual guidance toward, or confirmation of, its location.
According to a method of the present invention, the user, while operating computer system 12 for producing a work product, and having at least one hand near a home surface, realizes an idea possibly unrelated to the control of computer system 12. To assure that the idea receives attention in due course, the user records a voice message by (1) operating a switch that is located within reach from the home surface and (2) speaking a description of the idea so that the description is recorded. With the image of the work product unchanged on computer display 14 and the orientation of his or her hand near the home surface, the user quickly returns to productive work without substantial loss of train of thought or time or both.
In another embodiment of the present invention, the method further includes the steps of (1) observing a display indicating that a message has been recorded, and (2) operating a switch that is located within reach from the respective home surface to initiate audible play back of the message.
FIG. 2 is a top view of the mouse pad shown in FIG. 1. Voice messaging mouse pad 26 includes home surfaces 27 and 29, base 33, and battery powered module 30. Base 33 is of conventional foam laminate construction having a top surface for operating the rolling ball of a conventional mouse. Home surfaces 27 and 29 provide tactile orientation for quick identification of switches 32, 34, and 36 on module 30. Display 38 in the illustrated embodiment is a light emitting diode that indicates that a message has been recorded. Electret microphone 40 receives the user's speech and provides a corresponding electrical signal to an integrated circuit for recording. The integrated circuit provides a drive signal to speaker 40 so that the recorded message is audible during play back.
Module 30 is embedded by conventional techniques in a void in base 33. The top surface of the pad is made uniform so that movement of a conventional mouse over module 30 does not interfere with operation of the mouse or activate module 30. By locating module 30 in a void, the thickness of voice messaging mouse pad 26 does not exceed conventional mouse pad thickness. Access to a battery, not shown, that supplies power to module 30 is provided on the back face of pad 26 in a conventional manner.
Module 30 is an electronic subassembly of the type described in "Data Book--Voice Recording & Playback ICs" 1996, by Information Storage Devices, Inc., of San Jose, Calif., U.S.A., incorporated in full herein by this reference. The ISD1100 integrated circuit is used in a preferred embodiment. The integrated circuit (not shown), switch 32 (PLAYL), switch 34 (PLAYE), switch 36 (REC), microphone 42, speaker 40, LED (RECLED) 38, and battery (not shown) form a circuit of the type described by the schematic diagram at page 1-35. The circuit is conventionally assembled on a circuit board, according to layout design practices described on pages 3-75 through 3-80. Preferred component values are described on the schematic, on page 3-21, and pages 3-83 through 3-87. Functionally similar components, known by those of ordinary skill in the art, and component values selected for various conventional specific applications are used in equivalent embodiments. For example, an alternate and equivalent module embodiment includes a circuit of the type described in "MSM6688/6688L ADPCM Solid-State Recorder IC Datasheet" by OKI Semiconductor, Inc., of Sunnyvale, Calif., U.S.A., incorporated herein by this reference.
FIG. 3 is a top view of the wrist rest shown in FIG. 1. Voice messaging wrist rest 22 includes base 23, home surface 31, and battery powered module 130. Base 23 is of the conventional type of wrist rest formed of fabric covered foam. Module 130 is structurally and functionally similar to module 30 in FIG. 2. Module 130 is embedded by conventional technique in a void in base 23. Features of module 130 correspond to features of module 30, numbered less one hundred. The switches 132, 134, and 136 on module 130 are accurately located without visual guidance or confirmation and operated, for example, by the user's thumb while the user's index finger remains near home key "J" having home surface 21 on keyboard 20. Home surface 31, where the base of the user's hand or wrist rests during operation of keyboard 20, serves as an alternate home surface for reference during operation of switches 132, 134, and 136.
FIG. 4 is a top view of the keyboard shown in FIG. 1. Voice messaging keyboard 20 includes keyboard assembly 35 and battery powered module 230. Module 230 is structurally and functionally identical to module 30 in FIG. 2. Features of module 230 correspond to features of module 30, numbered less two hundred. Keyboard assembly 35 is of the conventional type used with a conventional personal computer. Module 230 is embedded by conventional technique in a void in keyboard assembly 35. Signals responsive to keyboard keys pressed by the user are coupled to computer system 12 by cable 39. Module 230 is located to be within reach of the index finger of the user's right hand without losing orientation with the home key 21 and home surface thereon.
FIG. 5 is a perspective view of the mouse shown in FIG. 1. Voice messaging mouse 24 includes mouse assembly 37, home surface 23, and battery powered module 50. Mouse assembly 37 is of the conventional type used with a conventional personal computer. An internal ball (not shown) protrudes from the underside of mouse assembly 37 to roll against a conventional mouse pad or equivalent surface. Signals responsive to movement of the ball are coupled to computer system 12 by cable 25. The construction and function of module 50 is identical to battery powered module 30 except that LED 52 and appropriate wiring is substituted for LED 38. By locating LED 52 away from module 50, LED 52 is made more noticeable by the user.
The foregoing description discusses preferred embodiments of the present invention, which may be changed or modified without departing from the scope of the present invention.
For example, those skilled in the art will understand that in alternate module embodiments power for the module (similar to module 230 or 50) is supplied by power conducted to the work station component wherein the module is located. For example, in an alternate embodiment of voice messaging keyboard 20, the module is powered by signals received from computer 12 on cable 39. In an alternate embodiment of voice messaging mouse 24, the module is powered by signals received from computer 12 on cable 25.
Further, those skilled in the art will understand that in alternate embodiments, the location of switches, microphone, speaker, battery, and indicators varies by design choice. Some or all of these components are recessed in various embodiments to reduce the possibility of unintentional activation of module functions or interference with conventional operations and movements. More sophisticated embodiments include additional similar switches for additional functions including, for example, erasing one or more previously recorded messages, activating one or more messages for periodic playback, recording additional messages with or without replacing previously recorded messages, playing back only part of a message, selecting any of several messages for immediate playback, skipping the remainder of a message after playback of that message has begun. Additional further embodiments include additional similar indicators for additional display functions including, for example, modes of operation, status of recorded messages, and the remaining capacity of battery and voice storage memory.
These and other changes and modifications are intended to be included within the scope of the present invention.
While for the sake of clarity and ease of description, several specific embodiments of the invention have been described; the scope of the invention is intended to be measured by the claims as set forth below. The description is not intended to be exhaustive or to limit the invention to the form disclosed. Other embodiments of the invention will be apparent in light of the disclosure to one of ordinary skill in the art to which the invention applies.
The words and phrases used in the claims are intended to be broadly construed. A "system" refers generally to electrical apparatus and includes but is not limited to electromechanical components in combination with a packaged integrated circuit, an unpackaged integrated circuit, a combination of packaged or unpackaged integrated circuits or both, a microprocessor, a microcontroller, a memory, a register, a flip-flop, a charge-coupled device, combinations thereof, and equivalents.
The conventional mouse, joy stick, track ball, touch pad, digitizing tablet, and pen input tablet are but a few examples of equivalent pointing systems. Equivalent pointing systems of the present invention include any of these conventional devices and their functional equivalents combined with battery powered module 30, battery powered module 50, or an equivalent module powered by computer system 12 as discussed above.
An input system in a first embodiment includes a pointing system as discussed above. Alternate and equivalent input systems include a conventional keyboard and other conventional switching apparatus designed with varying arrangement of keys for lower operator fatigue and higher accuracy. Equivalent input systems of the present invention include any of these conventional devices and their functional equivalents combined with battery powered module 30, battery powered module 50, or an equivalent module powered by computer system 12 as discussed above.
Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.
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A computer work station provides voice recording and playback without interruption of the user's working conditions, such as the appearance of the monitor screen, location of the user's hands over home positions, or direction of the user's gaze. A first work station embodiment includes a voice messaging mouse pad having a battery operated voice message module for record and playback using a microphone and speaker within the module. A second work station embodiment includes a voice messaging wrist rest that includes a similar battery operated voice messaging module. A third work station embodiment includes a voice messaging mouse that includes a similar battery powered voice messaging module.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to automatic pattern recognition in which an unknown input is compared to reference data representative of allowed patterns and the unknown input is identified as the most likely reference pattern.
2. Description of Related Art
Reference data for each member of a set of allowed patterns is stored and a test input compared with the reference data to recognise the input pattern. An important factor to consider in automatic pattern recognition is that of undesired variations in characteristics, for instance in speech or handwriting due to time-localised anomalous events. The anomalies can have different forms such as the communication channel, environmental noise, uncharacteristic sounds from speakers, unmodelled writing conditions etc. The resultant variations cause a mismatch between the corresponding test and reference patterns which in turn can lead to a significant reduction in the recognition accuracy.
The invention has particular, although not exclusive, application to automatic speaker recognition. Speaker recognition covers both the task of speaker identification and speaker verification. In the former case, the task is to identify an unknown speaker as one from a pre-determined set of speakers; in the latter case, the task is to verify that a person is the person they claim to be, again from a pre-determined set of speakers. Hereinafter reference will be made to the field of speaker recognition but the technique is applicable to other fields of pattern recognition.
To improve robustness in automatic speaker recognition, a reference model is usually based on a number of repetitions of the training utterance recorded in multiple sessions. The aim is to increase the possibility of capturing the recording conditions and speaking behaviour which are close to those of the testing through at least one of the utterance repetitions in the training set. The enrolled speaker may then be represented using a single reference model formed by combining the given training utterance repetitions. A potential disadvantage of the above approach is that a training utterance repetition which is very different from the test utterance may corrupt the combined model and hence seriously affect the verification performance. An alternative method is to represent each registered speaker using multiple reference models. However, since the level of mismatch normally varies across the utterance, the improvement achieved in this way may not be significant.
The methods developed previously for introducing robustness into the speaker verification operation have been mainly based on the normalisation of verification scores. The development of these methods has been a direct result of the probabilistic modelling of speakers as described in the article by M. J. Carey and E. S. Parris, “Speaker Verification”, Proceedings of the Institute of Acoustics (UK), vol. 18, pp. 99-106, 1996 and an article by N. S. Jayant, “A Study of Statistical Pattern Verification”, IEEE Transaction on Systems, Man, and Cybernetics, vol. SMC-2, pp. 238-246, 1972. By adopting this method of modelling and using Bayes theorem, the verification score can be expressed as a likelihood ratio. i.e. Verification Score = likelihood ( score ) for the target speaker likelihood ( score ) for any speaker
The above expression can be viewed as obtaining the verification score by normalising the score for the target speaker.
A well known normalisation method is that based on the use of a general (speaker-independent) reference model formed by using utterances from a large population of speakers M. J. Carey and E. S. Parris, “Speaker Verification Using Connected Words”, Proceedings of the Institute of Acoustics (UK), vol. 14, pp. 95-100, 1992. In this method, the score for the general model is used for normalising the score for the target speaker. Another effective method in this category involves calculating a statistic of scores for a cohort of speakers, and using this to normalise the score for the target speaker as described in A. E. Rosenberg, J. Delong, C. H. Lee, B. H. Huang, and F. K. Soong, “The Use of Cohort Normalised Scores for Speaker Verification”, Proc. ICSLP, pp. 599-602, 1992 and an article by T. Matsui and S. Furui, “Concatenated Phoneme Models for Text-Variable Speaker Recognition”, Proc. ICASSP, pp. 391-394, 1993. The normalisation methods essentially operate on the assumption that the mismatch is uniform across the given utterance. Based on this assumption, first, the score for the target speaker is calculated using the complete utterance. Then this score is scaled by a certain factor depending on the particular method used.
The invention seeks to reduce the adverse effects of variation in patterns.
In accordance with the invention there is provided a method of pattern recognition.
Thus the invention relies on representing allowed patterns using segmented multiple reference models and minimising the mismatch between the test and reference patterns. This is achieved by using the best segments from the collection of models for each pattern to form a complete reference template.
Preferably the mismatch associated with each individual segment is then estimated and this information is then used to compute a weighting factor for correcting each segmental distance prior to the calculation of the final distance.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 shows a first embodiment of speaker recognition apparatus according to the invention;
FIG. 2 shows the elements of a feature extractor for use in the speaker recognition apparatus shown in FIG. 1;
FIG. 3 shows an example of the reference data store of the apparatus shown in FIG. 1;
FIG. 4 is a graph showing the distances between three training utterances and one test utterance;
FIG. 5 shows the effect of the segment size on speaker verification performance;
FIG. 6 shows a second embodiment of the invention;
FIG. 7 shows a third embodiment of the invention;
FIG. 8 is a chart showing the experimental results comparing the performance of three embodiments of the invention and two prior art techniques for a single digit utterance;
FIG. 9 is a chart showing the experimental results comparing the performance of three embodiments of the invention and two prior art techniques for a ten digit utterance;
FIG. 10 is a graph showing the Equal Error Rate (EER) as a function of the number of competing speakers.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Pattern recognition apparatus generally operates in two modes: training and test. In the training mode, reference models are formed from the utterances of an allowed speaker. These reference models are then stored for subsequent use in speaker recognition, a test utterance from an unknown speaker being compared with the reference model for the claimed speaker (for verification) or with all the reference models for all the allowed speakers (for identification) and the comparison results being used to determined if the speaker is the or an allowed speaker.
The embodiments described herein are based on the use of a dynamic time warping (DTW) algorithm, and each allowed speaker is re presented using linearly segmented multiple reference models. Each reference model is formed using a single utterance repetition.
The invention involves evaluating the relative dissimilarities (or similarities) between each segment of a given test utterance and the corresponding segments in the collection of reference models (or reference data) for each registered speaker or, in the case of verification, the claimed speaker. The best individual reference segments for each targeted speaker are then selected to form a complete model for the purpose of identification/verification. All the reference models for a given utterance text are of the same length. To achieve this, the length of each template is made equal, in the training phase, to the mean length of all the available templates for the given text, by a linear decimation-interpolation technique for instance as described in C. S. Myers, L. R. Rabiner, and A. E. Rosenberg, “Performance trade-offs in dynamic time warping algorithms for isolated word recognition”, IEEE Transaction on Acoustics, Speech, and Signal Processing, Vol. ASSP-28, pp. 622-733, Dec. 1980. This process may be repeated during recognition trials to ensure that, for each given utterance text, the test and reference templates have the same duration.
A first embodiment of the invention is shown in FIG. 1 . Speaker recognition apparatus comprises an end-point detector 2 for detecting the start and end of an utterance in a received signal. Any suitable end-point detector may be used such as that described in “An Improved Endpoint Detector for Isolated Word Recognition” by L. F. Lamel, L. R. Rabiner, A. E. Rosenberg and J. C. Wilpon IEEE transactions on Acoustics, Speech, and Signal Processing , Vol. ASSP-29, No. 4, pp. 777-785, Aug. 1981 or “An Improved Word-Detection Algorithm for Telephone-Quality Speech Incorporating Both Semantic Constraints”, by J. C. Wilpon, L. F. Lamel, L. R. Rabiner and T. Martin AT&T Bell Laboratories Technical Journal , Vol. 63, No. 3, pp. 479-497, Mar. 1984.
Once the start of an utterance has been detected, the signal is passed to a feature extractor 4 which generates, for each frame, a feature vector of Mel Frequency Cepstum Coefficients (MFCCs) from the received signal. To this end, as shown in FIG. 2, the digitised speech is first pre-emphasised ( 41 ) using a simple first order digital network and then blocked into frames ( 42 ) of 200 samples with consecutive frames overlapping by 100 samples. Each speech frame is windowed ( 43 ) by a 200-sample Hamming window and then extended to 1024-point by padding it ( 44 ) with zeros at the end. The magnitude spectrum ( 46 ), which is obtained via a 10 th order FFT ( 45 ), is passed through a bank of 20 mel-spaced triangular bandpass filters ( 47 ) (the centre frequency of the first ten filters being linearly spaced up to 1 kHz and the remaining ten being logarithmically spaced) which simulate the critical band filtering. The log-energy output of the filterbank is transformed using a Discrete Cosine Transform (DCT) ( 48 ) to give the FFT-MFCC coefficients. Although this process produces 1024 coefficients, only the first 12 are used for the purpose of the invention. Other or additional co-efficients may be generated as required e.g. LPC-MFCCs.
The MFCCs are then input to a linear length adjustment unit 6 as shown in FIG. 1 . In unit 6 , the length of the input vector sequence (M frames) is adjusted to a predetermined length (N frames) by using a linear interpolation method. The modified feature vectors resulting from this process can be expressed as:
{tilde over (X)} {tilde over (m)} =(1−α)X m +aX m+1 {tilde over (m)}=1,2, . . . , N
where, x m is the m th original feature vector m = ⌊ ( m ~ - 1 ) ( M - 1 ) ( N - 1 ) + 1 ⌋ ,
and └ζ┘ denotes the greatest integer less than or equal to ζ and α = ( m ~ - 1 ) ( M - 1 ) ( N - 1 ) + 1 - m ,
In the training mode, the linearly adjusted MFCCs are stored in a reference data store 7 . As shown in FIG. 3, the reference data store 7 comprises a field 72 for storing an identifier of a pattern. For instance the reference data stored in the store 7 represents utterances of the same speech (e.g. a identification phrase) from four speakers 721 , 722 , 723 and 724 . Only one instance of an utterance of the phrase by speaker 721 is stored; three instances 7221 , 7222 and 7223 of an utterance of the phrase by speaker 722 are stored; two instances of an utterance of the phrase by speaker 723 are stored; and two instances of an utterance of the phrase by speaker 724 are stored. Each field 74 represents the linearly adjusted MFCCs generated for a frame of the training utterance. If the reference data represents the same utterance from each allowed speaker, the reference data is linearly adjusted such that the number of frames in each instance of reference data is equal to the mean number of samples for all the reference data. If the reference data represents different utterances for each allowed speaker, the reference data is linearly adjusted such that the number of frames in each instance of reference data is equal to the mean number of frames for the reference data for that allowed user.
In the test mode the linearly adjusted feature vector sequence is passed to the unit 8 where a set of DTWs are performed between the test utterance and the reference data. The DTW algorithm used in this work is similar to the one described in S. Furui, “Cepstral Analysis Technique for Automatic Speaker Verification,” IEEE Trans. on Acoustics, Speech and Signal Processing , Vol. ASSP-29, pp. 254-272, Apr. 1981, and consists of three steps:
Step 1: Initialsation: From m=1 to 1+δ=>D A (1,m)=d′(1, m)
Step 2: Main Recursion: From n=2 to N and for all m
If the point (m,n) satisfies the constraint M L (n)≦m≦M H (n) then D A (n,m)=d′(n,m)+min{D A (n−1,m)g(n−1,m),D A (n−1,m−1), D A (n−1,m−2)} P ( n , m ) = arg min [ m , m - 1 , m - 2 ] { D A ( n - 1 , m ) g ( n - 1 , m ) D A ( n - 1 , m - 1 ) , D A ( n - 1 , m - 2 ) }
Step 3: Termination: D = min N - δ ≤ M S ≤ N [ D A ( N , M S ) / N ] and M * = arg min N - δ ≤ M S ≤ N [ D A ( N , M S ) / N ]
In the above procedure δ is the maximum anticipated range of mismatch (in frames) between boundary points of the considered utterance, d′(n,m) is a weighted Euclidean distance between the n th reference frame and m th test frame and M L (n) and M H (n) are the lower and upper boundaries of the global constraint respectively and have the forms:
M L (n)=max{0.5n, (2n−N−δ), 1}, M H (n)=min{(2n+δ−1), 0.5(N+n),N}.
and g(m) is a non-linear weight which is given as: g ( n , m ) = { ∞ if D A ( n - 1 , m ) = min { D A ( n - 1 , m ) , D A ( n - 1 , m - 1 , D A ( n - 1 , m - 2 ) } 0 otherwise
The unit 9 involves the following backtrack procedure to obtain the frame level distances d(n), n=1. . . N which form the global distance D:
m=M*
From n=N to 1
d(n)=d′(n,m)
m=P(n,m)
For each allowed speaker, the smallest d(n) for a given segment (or frame) of this received signal is used to determine the optimum path. The output d(n) of the unit 9 is input to a decision unit 10 which determines the most likely speaker to be recognised.
In speaker verification, the test utterance is compared with the reference models for the claimed speaker. The claimed identity of the speaker is obtained via an input from the claimed user. This input may be in the form of spoken digits, DTMF signals, a swipe of a magnetic strip on a card or by any other suitable means to convey data to the speaker recognition apparatus. Once the claimed identity of a speaker has been obtained, the reference models for that claimed speaker are used to determine whether the speaker is the claimed speaker.
FIG. 4 is a graph showing the distances d(n) between each of three training utterances and a test utterance of a digit spoken by the same speaker. An examination of this figure clearly shows that the relative closeness of the reference data to the test data varies considerably and irregularly across the length of the utterance. By partitioning the utterance into shorter segments, a set of reference segments (from the given data for a given user) with the minimum distances from their corresponding test segments is selected. An important issue to consider in this approach is the size of the segments. Based on the graphs in FIG. 4, it can be argued that in order to minimise the overall distance, the segments should have the shortest possible length. DTW is one technique which provides the possibility of reducing the segment size to that covering only a single frame. This is because in DTW a state represents a frame of the training utterance. The overall distance for a given speaker can be obtained as the average of distances between the test utterance frames and the best corresponding frames in the reference set of the given allowed speaker. A trace of these distances is shown in FIG. 4, labelled (i).
FIG. 5 illustrates the effect of the segment size on the speaker verification performance. It is observed that the equal error rate (EER) increases almost linearly from 9.98% to 10.86% as the segment size is increased from one to ten frames. These results confirm the earlier suggestion that the approach performs best when the segments are of single frame size.
FIG. 6 shows a second embodiment of the invention in which elements common to FIG. 1 are indicated by like numerals. This second embodiment seeks to reduce further the effects of any existing mismatch between the test utterance and the generated best reference model. This is achieved by weighting each segmental distance in accordance with the estimated level of mismatch associated with that segment. The overall distance is then computed as the average of these weighted segmental distances. i.e. D = 1 N ∑ n = 1 N w ( n ) d ( n ) ( 1 )
where N is the adjusted number of frames in the given utterance, w(n) is the weighting factor for the n th segmental distance, and d(n) is the distance between the n th test frame and the corresponding frame n in the generated best reference model.
The dependence of the weighting factor w(n) on the segment index, as given in the above equation, provides the possibility of correcting each segmental distance in accordance with the associated level of mismatch. In order to determine these weighting factors, use can be made of a set of J speaker models that are capable of competing with the target model. In this case it can be argued that if, due to certain anomalies, there is some degree of mismatch between a segment of the test utterance (produced by the true speaker) and the corresponding segment of the target model, then a similar level of mismatch should exist between that test utterance segment and the corresponding segments of the competing reference models. Based on this argument an effective weighting function can be defined as: w ( n ) = ( [ 1 J ∑ j = 1 J d j ′ ( n ) ] ) - 1 ( 2 )
where J is the number of speakers in the selected competing set, and d j (n) are the distances between the n th segment of the test utterance and corresponding segments of the competing models. Equations (1) and (2) indicate that any segmental distance affected due to an undesired mismatch is appropriately scaled prior to the calculation of the overall distance. FIG. 6 illustrates the operations involved in this approach.
The identity of the unknown speaker is recognised or verified on the basis of the comparison i.e. the value of D will determine whether the unknown speaker is identified. The threshold value for D is determined a posteriori for each allowed speaker to result in the equal error rate (EER) for the speaker. Alternatively the threshold is determined a priori using statistical methods, for instance as described by J. P. Campbell “Features and Measures for Speaker Recognition” PhD Thesis, Oklahoma State University, USA, 1992
The competing model may be a conventional generic speech model which models speech rather than particular speakers. Alternatively, the competing speaker models can be pre-selected based on their closeness to the target model. In Examples A to C below, the J competing models are pre-defined for each allowed speaker in dependence on the similarities between the reference data for a given allowed user and the reference data for some or all of the remaining allowed users i.e. the J competing models for a particular speaker are those for which the reference data is most similar to the reference data for the particular speaker. Refer to equation 1 for the following examples.
EXAMPLE (A)
Assumptions:
the test utterance is produced by a true speaker
there are five segments (frames) in each utterance
d(n)=2, 3, 1, 5, 2
w(n)=1/3, 1/4, 1/3, 1/7, 1/4
N=5
therefore D=(1/5){2/3+3/4+1/3+5/7+2/4}=0.59285
In the above example the test utterance produced by the true speaker is more similar to the target model than the competing model.
EXAMPLE (B)
Assumptions:
the test utterance is produced by an impostor
Again N=5
d(n)=8, 10, 7, 9, 8
w(n)=1/6, 1/5, 1/4, 1/3, 1/2
Therefore D=(1/5){8/6+10/5+7/4+9/3+8/2}=2.4166
A large distance compared to case (A). Therefore the claimant is rejected.
EXAMPLE (C)
Assumptions:
the test utterance is spoken by an impostor
N=5
the test utterance is either
almost equally dissimilar from the target model and the competing model or, is more dissimilar from the competing model than the target model.
d(n)=8, 10, 7, 9, 8
w(n)=1/9, 1/11, 1/10, 1/12, 1/10
therefore D=(1/5){8/9+10/11+7/10+9/12+8/10}=0.6318118
The distance is very low and close to that produced in case (A).
A disadvantage of the above method of selecting J competing speakers is that, if an impostor produces a test utterance which is almost equally dissimilar from the target model and the competing models (example (C) above), then the approach may lead to a small overall distance, and hence the impostor may be accepted as the true speaker. This is simply because, in this case, the large segmental distances given by d(n,m) are almost cancelled out by the small values of w(n).
To overcome the above problem the competing speaker models may be based on their closeness to the given test input. With this method, when the test utterance is produced by the true speaker, the J competing speaker models can be assumed to be adequately close to the true speaker reference model. Therefore the method can be expected to be almost as effective as the previous approach. However, in the case of the test utterance being produced by an impostor, the competing speaker models will be similar to the test template and not necessarily to the target model. As a result d(n,m) and w(n) will both become large and the probability of false acceptance will be reduced significantly. This method of robust speaker verification is summarised in FIG. 7 . For the purpose of this description the above two methods involving weighting are referred to as segmental weighting type 1 (SWT1) and segmental weighting type 2 (SWT2) respectively.
Examples for SWT2
EXAMPLE (D)
When the test utterance is produced by a true speaker, the example is similar to the example (A) given above for SWT1.
EXAMPLE (E)
When the test utterance is produced by an impostor it is more dissimilar from the target model than from the competing model. This is because the competing model is selected based on its closeness to the test utterance.
N=5
d(n)=7, 9, 6, 10, 11
(1/w(n))=3, 1, 2, 4, 2
therefore D(n)=(1/5){7/3+9/1+6/2+10/4+11/2}=4.460
Therefore SWT2 is more effective than SWT1 in reducing false acceptance (for a given verification threshold).
The speech data used in the experimental study was a subset of a database consisting of 47 repetitions of isolated digit utterances 1 to 9 and zero. The subset was collected from telephone calls made from various locations by 11 male and 9 female speakers. For each speaker, the first 3 utterance repetitions (recorded in a single call) formed the training set. The remaining 44 repetitions (1 recorded per week) were used for testing.
The utterances, which had a sample rate of 8 kHz and a bandwidth of 3.1 kHz, were pre-emphasised using a first order digital filter. These were segmented using a 25 ms Hamming window shifted every 12.5 ms, and then subjected to a 12 th -order linear prediction analysis. The resultant linear predictive coding (LPC) parameters for each frame were appropriately analysed using a 10 th -order fast Fourier transform, a filter bank, and a discrete cosine transform to extract a 12 th -order mel-frequency cepstral feature vector [2,8,9]. The filter bank used for this purpose consisted of 20 filters. The centre frequencies of the first 10 filters were linearly spaced up to 1 kHz, and the other 10 were logarithmically spaced over the remaining frequency range (up to 4 kHz).
In order to minimise the performance degradation due to the linear filtering effect of the telephone channel, a cepstral mean normalisation approach was adopted. The technique involved computing the average cepstral feature vector across the whole utterance, and then subtracting this from individual feature vectors.
The effectiveness of the above methods was examined through a set of experiments. The results of this investigation are presented in FIG. 8 . It is observed that by using the proposed methods the error in verification can be significantly reduced.
The relative effectiveness of the multiple reference model-based methods is also examined in experiments using a sequence of ten digits. Results of this study (FIG. 9) again confirm that the use of segmental weighting leads to a considerable improvement in speaker verification.
The main drawback of SWT2 is its computational complexity owing to the large number of DTW-based comparisons to be carried out to select the competing speakers. This problem can, to a certain extent, be overcome by selecting the competing speakers through a method which is computationally more efficient. The DTW technique may then be used for the subsequent parts of the operation. It should be noted that the technique used to replace DTW for selecting competing speakers may not be as efficient. It is therefore possible that the selected competing speakers are different from those that should, and would, be obtained with DTW. An alternative approach would be to use a computationally efficient method to select a larger-than-required number of competing speaker models and then reduce this using DTW.
To investigate this idea, a vector quantisation (VQ) algorithm with a codebook of size 8 was used for nominating competing speakers from the set of registered speakers during each verification trial. The required number of competing speakers was set to 2 and the selection of these from the group of nominees was based on the use of DTW. The speaker verification trials were performed by incrementing the number of nominated competing speakers from 2 to 15. FIG. 10 shows the results of this study in terms of the equal error rate as a function of the number of nominated competing speakers. This figure also shows the EER obtained using the original form of SWT2 in which the two competing speakers are selected using the DTW approach. It should be pointed out that, when only two speakers are nominated by the VQ approach, these will essentially be considered as the selected competing speakers. In this case, since DTW is not used in selecting the competing speakers, the computational efficiency of the method is maximised. However, as seen in FIG. 10, the associated EER is considerably higher (over 3%) than that for the original SWT2. As the number of nominees exceeds the required number of competing speakers, the computational efficiency of the approach reduces. This is because DTW has to be used to make the final selection from an increasing number of nominated speakers. This, on the other hand, results in a reduction in the verification error. It is observed in FIG. 10 that as the number of speakers nominated by VQ reaches 9, the resultant EER becomes exactly equal to that of the original SWT2 method. This clearly indicates that the top two competing speakers are amongst the group of nominees. In this case, since DTW is applied to less than half the speaker models in the set, the computational efficiency of the approach is considerably improved without any loss in the verification accuracy.
To compare the performance of the invention with that of known normalisation methods, experiments were conducted using SWT2 and unconstrained cohort normalisation (UCN) which is a comparable normalisation technique as described in an article by A. M. Ariyaeeinia and P. Sivakumaran, “Speaker Verification in Telephony”, Proceedings of the Institute of Acoustics (UK), Vol. 18, pp. 399-408, 1996.
Results of these experiments, which were based on using single digits as well as a sequence of ten digits, are presented in Table 1. It is observed that in both cases there is a considerable difference in performance in favour of SWT2. These results clearly confirm the superior performance of the invention for robust text-dependent speaker verification.
Average EER
EER Based on
Based on
a Combination of
Method
Single Digits
all 10 Digits
UCN
7.17
0.41
SWT2
5.92
0.19
Table 1. Equal Error rates (%) for SWT2 and UCN in speaker verification experiments based on single digits and a combination of all ten digits.
Although the description so far has made reference to DTW techniques, the invention may be implemented using other modelling techniques such as Hidden Marker Models (HMMs). In this case, each utterance from an allowed speaker may be stored using single state, multi-model HMMs. Each state of the HMM represents a frame of the utterance and each mode represents a training utterance for the given allowed speaker.
The invention may also be used in the recognition of patterns other than speech for instance image recognition. In this case reference data is stored for each of the images to be recognised. At least one of the images has at least two instances of reference data representing the image. During recognition, successive segments of an unknown input signal are compared to the reference data and, for that or those images that have more than one instance of reference data, a composite comparison result is formed from the best scoring segments of the reference data. A weighting factor may be applied as described with reference to the speaker recognition implementation.
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A method and apparatus for pattern recognition comprising comparing an input signal representing an unknown pattern with reference data representing each of a plurality of pre-defined patterns, at least one of the pre-defined patterns being represented by at least two instances of reference data. Successive segments of the input signal are compared with successive segments of the reference data and comparison results for each successive segment are generated. For each pre-defined pattern having at least two instances of reference data, the comparison results for the closest matching segment of reference data for each segment of the input signal are recorded to produce a composite comparison result for the said pre-defined pattern. The unknown pattern is the identified on the basis of the comparison results. Thus the effect of a mismatch between the input signal and each instance of the reference data is reduced by selecting the best segments from the instances of reference data for each pre-defined pattern.
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BACKGROUND OF THE DISCLOSURE
The present disclosure is directed to a safety detonator intended for use in down hole apparatus, particularly for use in a perforating gun assembly.
A perforating gun assembly normally incorporates an elongate tubular sleeve or body which internally encloses multiple shaped charges. Upon detonation, the shaped changes form perforations extending outwardly radially of the well borehole and pass through the surrounding housing or assembly, and additionally form deep penetrating fluid flow passages through the surrounding casing, cement and into the adjacent formations. To assure proper detonation of the shaped charges, a detonator assembly is incorporated in the perforating gun assembly. The detonator assembly is connected to the surface via an electrical conductor, and when properly detonated, it provides detonation in a predetermined timed sequence to a detonation cord which connects with each of the shaped charges. The detonator assembly is therefore the key safety device in operation of the equipment.
Heretofore, detonator assemblies have been constructed with an electrically triggered detonator which is coupled through a passage or open space to a non-electric detonator adjacent to a detonating cord. On application of an electrical signal the electric detonator detonates, thereby, producing a shock wave or impulse which is transferred across the open space to the non-electric detonator. The non-electric detonator in turn is detonated, coupling the charge from the original electrical impulse into the detonating cord and to the shaped charges so that each charge of the perforating gun assembly is sequentially detonated. The detonator assembly has been intended as a safety device. There is a balance in the geometry of the detonating apparatus because the spacing between the electrically fired detonator and the non-electric detonator is crucial to safety.
The two critical dimensions of the spacing or passage, known in the industry as the "fire channel", coupling the electrically fired detonator to the non-electric detonator is the diameter (D) and the length (L). If D is too small, it acts as a choke and not enough force is transmitted through the fire channel to insure proper detonation of the non-electric detonator. If the distance L is too long, the same problem exists, i.e. not enough force is transmitted through the fire channel to insure proper detonation of the non-electric detonator. This often results in a low order detonation whether or not there is fluid in the fire channel. If the distance L is shortened to overcome the above described detonation problem, when dry, it increases the percentage of "fires" when the fire channel is filled with fluid, which is also undesirable.
Generally, the fire channel between the electrically fired detonator and the non-electric detonator is kept clear of well fluid. However, an opening is typically drilled in the detonator assembly which intentionally delivers well fluid into the fire channel. If the perforating gun assembly is exposed to well fluids, it is important that it not fire and fluid introduced in this region normally prevents firing. The length L must be sufficiently long that fluid in the tool dampens, even prevents transfer of the detonation shock wave. On the other hand, the components must be close enough to assure that the electrical impulse does in fact detonate the electrically fired detonator and make the necessary transfer to the non-electric detonator. Accordingly, the length L should not be too long or too short. If L is too long, misfiring will occur because the shock wave is attenuated as it travels through the long distance. If the length L is too short, then the safety system which responds to well fluids around the perforating gun assembly will not operate. As the length L is reduced, firing may still nevertheless occur because the well fluids do not totally prevent shock transfer from the electrically fired detonator to the non-electric detonator. Accordingly, this suggest that the length L be increased.
Control of the length L is thus difficult, being almost a balance of terror, where misfires occur because the shock wave does not get to the non-electrical detonator where L is too great, and unintended firings occur where L is too short and the perforating gun assembly is submerged in well fluids.
The present disclosure sets out a system which overcomes these risks and provides a much safer detonator assembly. The detonator assembly of the present disclosure avoids the dimensional sensitivity to the measure L as described above. Rather, the detonator assembly of the present disclosure couples the electrically fired detonator to the non-electric detonator through an open area which is in the form of a passage. The passage is somewhat short, sufficiently short to assure that coupling does occur so that transfer of the explosive shock wave assures detonation. The passage connecting the electrically fired detonator to the non-electric detonator is an open passage which is plugged by a solenoid operated plug. Thus detonation transfer into the passage is intentionally removed. Accordingly, the electrically fired detonator is not coupled with the non-electric detonator during transit, during arming of the device, during assemlby of the perforating gun, and at all other times. It is kept safe because there is isolation between the detonators.
The perforating gun assembly is a dangerous device to be handling. One of the dangers arises from stray electrical currents. The electrical currents typically arise in the context of handling such a device. It is normally loaded on a service vehicle such as a truck which carries a number of other devices and logging tools. It is not uncommon to load this device in the assembled state on a truck along with other logging devices. The truck normally is equipped with a reel or drum of electrical cable which is wrapped in a special fashion and which is otherwise described as an armored logging cable. The logging cable may support a great variety of electrical or nuclear logging devices which are carried on the same truck. All these devices connect with a variety of power supplies through the logging cable. The service vehicle normally connects the logging cable with one or more logging tools which respond to all types of electrical currents including high frequency AC, low frequency AC, and direct current, both positive and negative in polarity. The existence of electrical current generating equipment on such a truck runs the risk of creating stray currents, both in transit and at the site. Stray currents are a significant problem for perforating gun assemblies whether equipped with conventional detonators known heretofore or the high energy type detonators which are currently popular. High energy detonators require substantially more electrical power for operation. Accordingly, the truck mounted power supplies have large outputs so that high energy detonators can be triggered. The present apparatus takes advantage of a sequence of operations including polarity reversals to assure that the present device is fired intentionally, and does not fire in accidental circumstances. In other words, the device both in a stored situation or in a perforating gun assembly prior to intentional firing has a polarity sensitive circuit which assures that firing occurs only on the right voltage application to the device. Moreover, it includes means rejecting AC currents and hence does not fire when an AC current is applied to it.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 shows a perforating gun assembly incorporating multiple shaped charges and is the device which is triggered into operation to form perforations as a result of proper and safe detonation by the detonator assembly of the present disclosure;
FIG. 2 is an enlarged view showing the detonator assembly of the present disclosure including details of construction thereof;
FIG. 3 is an enlarged view of the detonator assembly showing the solenoid plug retracted to open fire channel of the detonator assembly;
FIG. 4 is an enlarged view of the wet switch safety feature of the detonator assembly of the present disclosure;
FIG. 5 is an enlarged view of the wet switch safety feature of the present disclosure showing cable conductor grounding rendering the detonator assembly inoperable; and
FIG. 6 is a schematic wiring diagram of the detonator assembly showing circuit connections for safe operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is now directed to FIG. 1 of the drawings which shows a perforating gun assembly utilizing the detonator assembly of the present disclosure. The perforating gun assembly 10 includes an elongate cylindrical sleeve or housing 11 which is threaded to or attached to a sub 12. The sub connects with a neck 13 which includes a conventional fishing neck of standard construction, and which axially aligns with an armored logging cale 14. A logging cable encloses one or more conductors for electrical communication from the surface. At the surface, a voltage source to be described is operated to provide a firing signal on the conductor in the cable 14.
The device 10 includes a closure member 15 which plugs the upper end of the sleeve or housing 11 making up the elongate housing. The housing 11 can be short for enclosing only a single shaped charge, or it can be quite long to enclose many similarly shaped charges. They are installed in similar fashion repetitively along the length of the structure. The shaped charges 16 are typically positioned opposite scallops 17 at the exterior which have a reduced thickness to show the location of the shaped charges and to enable the plume of fire generated upon detonation to be directed more readily through the thinner regions at the scallops 17. The detonator assembly 20 of the present disclosure is installed at the lower end of the cylindrical housing 11. The lower end of the housing 11 is closed by a bull plug 18 located at the bottom of the housing. The perforating gun assembly 10 is sealed so that the interior chamber of the housing 11 excludes well fluids. A dry atmosphere is maintained around the shaped charges 16, detonator assembly 20 and the detonating cord 21.
The detonator assembly 20 is located at the bottom of the housing 11 and is therefore exposed to any fluid which might enter the perforating gun assembly 10 through an inadvertent leak. Recall that the perforating gun assembly 10 is preferably dry on the interior. Should a leak occur, any fluid will accumulate at the bottom end of the housing 11, and the fluid at the bottom end will prevent firing. This safety feature is incorporated in the detonator assembly 20 of the present disclosure.
Going now to FIG. 2 of the drawings, the detonator assembly 20 is shown in greater detail. It is formed of a plastic shell or housing 22 with a passage drilled therethrough to enable the detonating cord 21 to be positioned in the passage. In any event, it extends to the other shaped charges for detonation. It is immediately adjacent to a chamber 23 for receiving a non-electric detonator 24. The detonator 24 is a material which is relatively difficult to detonate. It is preferably made of explosive materials which are relatively insensitive. Accordingly, the detonator 24 is installed in the chamber 23 immediately adjacent to the detonating cord 21, and its mode of detonation will be set forth in greater detail as will be detailed herein.
The housing 22 has a coil 25 cast therein with conductors extending to the exterior of the coil 25 for connection as will be discussed. This is immediately adjacent to a metal plunger 26 connecting with a stem 27 which connects to a plug 28. These components move together as a unit. They are moved into the coil 25 when electrical current is applied to the coil 25 and locked in the armed position by spring latch 29 as shown in FIG. 3.
Referring now to FIG. 3, another component shown in the detonator assembly 20 is a coil 30 which is embedded in the structure of the device and which is connected by suitable wires with the circuitry. Additional circuitry that is embedded in the system includes the diodes 31 and 32. Their connections will also be described. A ground strap 33 extends through a transverse opening 34 which is formed in the housing 22, and a solid pellet 35 is positioned against the ground strap 33, as more clearly shown in FIG. 4. A coil spring 36 bears against the pellet 35. The coil spring 36 is made of metal. It is connected in circuitry as will be shown in the schematic discussed below. The coil spring 36 forces the pellet 35 against the ground strap 33.
The pellet 35 is made of insulative material. There is no current conducted to the ground strap 33 through the pellet 35 as long as it is in place. It is interposed between the coil spring 36 and the ground strap 33. It is preferably made of a material which dissolves readily in the fluid anticipated in the borehole. For instance, if conventional drilling fluid is use, it is ordinarily made by mixing various barites with water. To this end, the pellet 35 is preferably a material which is soluble in water. As an example, various and sundry salts can be used for this purpose. When exposed to water, the pellet 35 is dissolved, thereby permitting the coil spring 36 to expand and contact the ground strap 33. When this occurs, shorting to ground occurs which is important in operation of the detonator assembly 20.
In effect, the coil spring 36 is connected to operate as a controllable switch which is in a normally open condition. Separately, another switch member 38 is included. This switch is affixed to the stem 27 just mentioned and moves from a first switched position to a second position as will be detailed.
The reference numeral 40 identifies a chamber incorporated for receiving an electrically fired detonator therein. The electrically fired detonator is normally constructed as an elongate cylindrical member and in this instance, is identified at 42. The detonator 42 is electrically fired. It forms a shock wave which travels along a transverse passage 43. The passage 43 extends from the electrically fired detonator 42 to the non-electrical detonator 24 to couple the shock wave between the two explosives. The shock wave is propagated along the passage 43. The passage 43 is controlled so that the length of the passage 43 between the detonators 24 and 42 is controllably short. This assures that the shock wave is propagated along the passage 43 and impinges on the detonator 24, causing its detonation. Prior to arming the detonator assembly 20, the passage 43 is plugged by the plug 28 previously mentioned. The plug 28 is sized in conjuction with the passage diameter so that substantially the entire passage 43 is plugged. The plug 28 is sufficiently large that it blocks access to the non-electric detonator 24 when the plug 28 is in the position shown in FIG. 2 of the drawings. When the plug 28 is raised, the passage 43 is cleared for easy signal transmission.
The passage 43 does not include any means of access for well fluids. It is not necessary however, that well fluids enter the passage 43 to provide the safety interlock in the event the perforating gun is submerged and leakage occurs within the perforating gun assembly 10 as discussed earlier. Rather, another system is included to provide an interlock for protection in this regard. Going now to FIG. 6 of the drawings, the numeral 48 identifies a surface firing panel which provides appropriate electrical power to the conductor 49. The conductor 49 is in the armored cable 14 shown in FIG. 1. This electrical conductor extends to the perforating gun assemlby 10 and connects with the electrically fired detonator 42 shown in FIG. 2 and comprises a portion of the circuitry shown in schematic form at FIG. 6. The cable 14 thus supports the conductor 49 which is input to the coil 30 previously illustrated in FIG. 2. The coil 30 is arrange serially. It has sufficient inductance to block current flow for any AC input. The diode is serially connected with the coil 25 to operate the solenoid plug 28. In addition, the diode 32 is connected with the contact 51 which is at the left hand end or nearer the plunger 26. The contacts 52 and 53 are likewise included. The moveable switch member 38 supported by the stem 27 makes contact across two of the three terminals as shown in the drawing. On movement, it makes contact with another pair. In the off or running position shown in FIG. 2, the switch member 38 spans contacts 52 and 53; it spans the contacts 51 and 52 when moved to the armed postion shown in FIG. 3.
The contact 52 connects serially through the fired detonator 42. It also then connects to ground which is the ground strap 33 previously mentioned. The group strap 33 connects to ground through the coil spring 36. Recall that the coil spring 36 is held in the normally open condition by the pellet 35. The pellet 35 is included to block the switch normally open so that no current flows to ground.
Operation of the system of the present disclosure is now considered. Assume that the surface firing panel 48 includes a battery. Assume further that unwanted or stray AC currents are detected by the conductors 49 in the cable 14. In that instance, any AC currents to the equipment in the perforating gun assembly 10 are blocked by the high frequency coil 30. It preferably has a relatively high inductance to block the current flow. It preferably passes only DC or very low frequency AC current, substantially lower than 60 cycles. Ideally, the coil 30 is relatively high in inductance to serve as a barrier to AC current flow into the perforating gun assembly 10. Assume that a battery, included at the surface firing panel 48, is ready for use. In that instance, the following sequence of operations and events must occur. First, a negative current must be applied to the cable 14. The negative current can flow only through the diode 31. However, even this will not happen if the perforating gun assembly 10 is wet, i.e., meaning that the perforating gun has been submerged in drilling fluid which has leaked into the structure whereupon grounding will occur. For running and arming, it is assumed that the pellet 35 remains intact and is not dissolved as would occur on exposure to borehole fluids.
The first step is therefore to apply a negative pulse of substantial current flow. The duration should be sufficient to operate the solenoid coil 25 at a substantial current level. For instance, a current flow of 500 ma is first applied for about one half to one second. Application of current for a longer duration does not make any difference. When this occurs, the current is permitted to flow through the solenoid coil 25 and triggers the mechanical change which arms the device. Prior to movement of the plunger 26 and connecting stem 27, the device was not armed because the connective switch member 38 shorted the electrically fired detonator 42 to ground. Therefore, current flow through the solenoid coil 25 provides arming of the device by moving the switch member 38 to connect across the terminals 51 and 52. After that has been accomplished, the current is stopped and the perforating gun assembly is then armed for operation. Next, a current of about 500 ma is again applied. In this instance, the current must be positive so that the diode 32 will pass the current flow. Accordingly, a positive pulse applied first accomplishes nothing because it passes the diode 32 but cannot flow to any part of the circuitry and is blocked by the diode 31. Therefore, the first pulse must be a negative pulse of DC current. AC current will not pass the the coil 30 while a negative DC pulse will pass the diode 31 and provide a magnetic field from the solenoid coil 25 which moves the plunger 26 thereby clearing the passage 43. Thereafter, a positive current pulse is again applied. This current pulse is passed by the diode 32 and flows through the terminal 51, the switch member 38, the terminal 52 and flows through the detonator 42. This is sufficient to detonate the explosive. At this juncture, the explosive shock wave travels through the passage 43 and impinges on the detonator 24, detonating the detonator 24 and in turn detonating the detonator cord 21.
It is understood that the polarity used in the preferred embodiment is for illustration purposes only. It can readily be seen that by reversing diodes 31 and 32, and reversing the current polarity sequence, the same result is obtained.
The system described above is insensitive to AC, and indeed rejects AC currents. It will not be triggered by AC signals. This is true both in the running position and the armed position. It is also true in the stored condition. Separately, it is responsive to a sequence of DC current pulses. The sequence is a negative current pulse first and a positive current pulse thereafter. The negative current pulse is necessary to operate the solenoid coil 25 which in turn clears the passage 43 to thereby arm the detonator. In addition, the negative current pulse moves the switch member 38 to bridge the contacts 51 and 52.
In addition to the above safe guards, a safety interlock is incorporated whereby the pellet 35 responds to unintended leaks of borehole fluid. This is protective of firing when a leak has occured. Accordingly, if the detonator assembly 20 is dry, the wet switch formed by the spring 36 and the ground strap 33 is held open. In the storage condition and the running position, the wet switch is normally open. If it closes at any time, it completely grounds all input currents to the detonator. Closure of the wet switch is thus occasioned by dissolving the pellet 35, and the spring 36 mechanically assures closure to the ground strap 33.
While the foregoing is directed to the preferred 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 which follow.
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A fluid sensitive, polarity sensitive safety detonator system for use in a perforating gun assembly is disclosed. The detonator system is housed within the perforating gun housing and is operatively connected to surface located detonating means. A non-electric detonator is selectively coupled with an electrically fired detonator so that the detonators are not coupled during transit, during arming of the device, during assembly of the device and at all other times. A polarity sensitive circuit selectively arms the detonator assembly and a safety interlock system automatically grounds the detonator assembly upon intrusion of borehole fluids within the peforating gun housing.
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CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of U.S. application Ser. NO. 748,151, filed Aug. 22, 1991.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to processes for shaping ceramic parts from powders, and molding compositions therefor. More particularly, the invention is directed to molding processes and molding compositions for forming high quality, complex parts which exhibit excellent green strength and which can be readily fired without experiencing the cracking, distortion and shrinkage problems commonly associated with prior art sintered products.
2. Description of the Prior Art
Several forming methods for ceramic bodies are commonly practiced. In one popular shape forming method, namely, slip casting, a liquid suspension of ceramic powder is "de-watered" in a porous mold, producing a powder cake in the shape dictated by the mold. Dry pressing involves compaction of a powder in a die. The powder usually contains a processing aid which serves as plasticizer and/or binder for the green compact.
One objective of any forming method is to produce green parts which can be sintered to a shape reproducible to close dimensional tolerances, free from defects During green-forming and sintering, cracks, distortions and other defects can arise due to the shrinkage associated with the particle consolidation processes. It is generally recognized that these defect-producing processes are mitigated by producing green bodies of high green density, which reduces the amount of shrinkage that the body must undergo during consolidation and sintering.
Another objective of shape-forming methods is to produce articles having net-shape, eliminating or minimizing the need for downstream operations, such as machining, to obtain final part dimensions. Dry pressing, in particular, frequently requires additional downstream processing in the form of machining and diamond grinding to attain intricate shapes, non-symmetrical geometrical formats and close tolerances.
Injection molding is recognized as a premier net-shape forming method for ceramic and metal powders. However, to realize the potential economic benefits offered by injection molding over other recognized less net-shape forming methods (e.g., dry pressing), it is necessary to minimize the number and complexity of the processing steps involved in the overall process. In addition, it is desirable that the molding compositions allow high solids loading to minimize shrinkage during binder burn-out and sintering to minimize defects as described above.
U.S. Pat. No.4,113,480 discloses the use of agaroid binders in forming ceramic or metal parts. The examples cited reflect relatively low solids concentrations, <40 vol % of the formulations. Furthermore, the preferred embodiment of the process, as exemplified in the flow chart appearing in FIG. 2 of the drawings, teaches a sequence of steps including a step in which the batch formulation is concentrated in solids by evaporation of some of the water required in preceding processing operations. Evaporation of large amounts of water as a means of solids adjustment is a time and cost penalty, that in certain cases, renders the injection molding process uneconomical with respect to other shape forming processes.
SUMMARY OF THE INVENTION
The present invention provides aqueous molding compositions and a process useful in forming ceramic articles. Advantageously, molding is carried out at high solids loading and maintained thereat during processing, thereby eliminating the need to concentrate the molding formulations by evaporation of large amounts of water. More specifically, in accordance with the invention, there is provided a process for shaping parts from ceramics which comprises the steps of forming a concentrated mixture in excess of 40% ceramic content by volume comprising ceramic powder(s), a gel-forming material chosen from the class of polysaccharides known as agaroids, and a gel-forming material solvent the mixture being formed in a blender that provides shearing action thereto and the blender being heated to raise the temperature of the mixture to about 70° C. to 100° C., and preferably about 80° C. to 95° C.; supplying the mixture to a mold, and molding the mixture under conditions of temperature and pressure to produce a self supporting structure.
The invention is also drawn to an injection molding process comprising the steps of forming a concentrated mixture in excess of 40% ceramic content by volume comprising ceramic powder(s), a gel forming material chosen from the class of polysaccharides known as agaroids, and a gel forming material solvent, the mixture being formed in a blender that provides shearing action thereto and the blender being heated to raise the temperature of the mixture to about 70° C. to 100° C., and preferably about 80° C. to 95° C.; injecting the mixture at temperature above the gel point of the gel forming material into a mold, cooling the mixture in the mold to a temperature below the gel point of the gel forming material to produce a self supporting structure and removing the structure from the mold.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood and further advantages will become apparent when reference is made to the following detailed description and the accompanying drawings in which:
FIG. 1 is a graphic representation of the apparent viscosity of a 2 wt % aqueous solution of agar at various temperatures; and
FIG. 2 is a schematic representation of the basic steps of one embodiment of the process of the invention.
DETAILED DESCRIPTION OF THE INVENTION
As used herein the term ceramic powder is intended to include, without limitation, powders of such materials as oxides, borides, nitrides, silicides, and carbides of metals, non-metals or mixtures thereof, and mixtures of such materials.
According to the process of this invention, the ceramic powder is initially mixed with a gel forming material and a solvent for the gel forming material. This mixture is proportioned with a carrier to be fluid enough to enable it to be readily supplied to a die by any of a variety of techniques, and especially by injection molding. Generally, the amount of powder in the mixture is between about 35% and about 60% by volume of the mixture. Preferably, the powder constitutes between about 40% and about 58% by volume of the mixture, and most preferably constitutes between about 45% and about 55% by volume of the mixture. The preferred and most preferred amounts are especially suited for production of net and near net shape injection molded parts.
The gel forming material employed in the mixture comprises an agaroid An agaroid has been defined as a gum resembling agar but not meeting all of the characteristics thereof (See H. H. Selby et al., "Agar", Industrial Gums, Academic Press, New York, N.Y., 2nd ed., 1973, Chapter 3, p. 29). As used herein, however, agaroid not only refers to any gums resembling agar, but also to agar and derivatives thereof such as agarose. An agaroid is employed because it exhibits rapid gelation within a narrow temperature range, a factor which can dramatically increase the rate of production of articles. More importantly, the use of such gel forming materials substantially reduces the amount of binder needed to form a self supporting article. Thus, articles produced by using gel forming materials comprising agaroids can significantly enhance the production of net shape and near net shape objects. Moreover, the production of complex articles from agaroid containing mixtures is dramatically improved as a result of the substantial reduction in the firing regimens necessary to produce a fired product. The preferred gel forming materials are those which are water soluble and comprise agar, agarose, or carrageenan, and the most preferred gel forming materials consist of agar, agarose, and mixtures thereof. FIG. 1 illustrates the basic features of the gel forming material by graphically depicting the change in viscosity of a preferred gel forming solution (2 wt % agar solution). The graph illustrates the features of our gel forming materials: low gel forming temperature and rapid gelation over a narrow temperature range.
Gel strength of the gel forming material is measured by using an apparatus commonly employed in the manufacture of industrial gums. The apparatus consists of a rod having a circular cross-sectional area of 1 cm 2 at one end thereof which is suspended above one pan of a triple beam balance. Initially, a large container is placed on each pan of the triple beam balance. The container placed on the pan (above which the rod is suspended) is filled with about 200 mL (volume) of a gel consisting of about 1.5 wt % of the gel forming material and water. The empty container is then balanced against the gel containing vessel. The rod is then lowered into contact with the top surface of the gel. Water is then metered into the empty container and the position of the balance pointer is continuously monitored. When the top surface of the gel is punctured by the rod, the balance pointer rapidly deflects across the scale and the water feed is immediately discontinued. The mass of water in the container is then measured and the gel strength (mass per unit area) is calculated.
The gel forming material is provided in an amount between about 0.5 wt % and about 6 wt % based upon the solids in the mixture. More than about 6 wt % of the gel forming material may be employed in the mixture. Higher amounts are not believed to have any adverse impact on the process, although such amounts may begin to reduce some of the advantages produced by our novel compositions, especially with respect to the production of net shape and near net shape bodies. Most preferably, the gel forming material comprises between about 1% and about 3% by weight of solids in the mixture.
The mixture further comprises a gel forming solvent; the solvent is added in an amount sufficient to dissolve the gel forming material. While any of a variety of solvents may be employed depending upon the composition of the gel forming material, particularly useful solvents for agaroid containing gel forming materials are polyhedric liquids, particularly polar solvents such as water or alcohols. It is, however, most preferable to employ a solvent which can also perform the dual function of being a carrier of the mixture, thus enabling the mixture to be easily supplied to a mold. We have discovered that water is particularly suited for serving the dual purpose noted above.
A liquid carrier is normally added to the mixture to produce a homogeneous mixture of the viscosity necessary to make the mixture amenable to being molded by the desired molding process. Ordinarily, the liquid carrier is added in an amount that is necessary to produce a homogeneous mixture and to insure the proper fluidity of the mixture. Generally, the amount of a liquid carrier is an amount between about 40% to about 60% by volume of the mixture depending upon the desired viscosity thereof less the amount of solvent employed to dissolve the gel forming material. In the case of water, which performs the dual function of being a solvent and a carrier for agaroid containing mixtures, the amount is simply between about 40% and about 60% by volume of the mixture, with amounts between about 45% and about 55% by volume being preferred. In addition, because of its low boiling point, water is easily removed from the self supporting body prior to and/or during firing.
The mixture may also contain a variety of additives which can serve any number of useful purposes. For example, dispersants (e.g., Darvan C ) may be employed to ensure a more homogeneous mixture. Lubricants such as glycerine may be added to assist in feeding the mixture along the bore of an extruder barrel and additives such as glycerine to reduce the vapor pressure of the liquid carrier and enhance the production of the near net shape objects. The amount of additives will vary depending on the additive and its function within the system. However, the additives must be controlled to ensure that the gel strength of the gel forming material is not substantially destroyed. For example, dispersing agents such as Darvan C are ordinarily added in an amount of about 1% by weight of the solids in the mixture, whereas glycerine may be added in amounts ranging from about 1% to about 10% by weight or higher of the mixture without adversely affecting the gel strength of the gel forming material while maintaining the required performance levels of the additives. Table 1 describes additives such as lubricants and vapor pressure reducers and their effect upon the gel strength of the gel forming material (measured at room temperature).
TABLE 1______________________________________Effect of Additives Agar Gel StrengthAdditives (Wt %) (wt %) (g/cm.sup.2) nominal______________________________________None -- 3.6 1850s-butanol 4 4 1900Ethylene glycol 4 4 1900Glycerine 11 3 1700Glycrine 18 3 1750______________________________________
The components of the molding formulation are compounded in a heated blender that provides shearing action thereto creating a homogeneous mixture of high viscosity. The shearing action is instrumental in producing compositions of high solids loading in a dispersed and uniform state, highly suitable for subsequent injection molding. Ability to form uniform compositions of high solids loading is desirable in the production of injection molded parts. Use of compositions with high solids concentration results in lower shrinkages when the molded parts are dried and fired, facilitating dimensional control and mitigating the tendency for cracks to form during the densification process. The benefits afforded by this process include higher yields of acceptable product and lower scrap rates. This can have a significant effect on the cost of the overall process and may determine whether injection molding is lower in cost relative to other fabrication processes for a particular component.
As practiced in the current invention, the blended composition containing the components of the ceramic mixture, water, dispersant, other additives, if used, and the agaroid was removed from the blender after cooling to a temperature below the gel point of the agaroid, and further shredded to form a material having a particulate consistency. This was especially useful in producing material in a form convenient for molding in conventional injection molding machines, and for being able to store the material for molding at a later date. Alternatively, the material after blending could be granulated before cooling, e.g., by passing the material directly through an extruder and cutting the extrudate as it exits the die.
The mixture is transported to the mold at a temperature above the gel point (temperature) of the gel forming material. Ordinarily, the gel point of the gel forming material is between about 10° C. and about 60° C., and most preferably is between about 30° C. and about 45° C.
The mixture is supplied to the mold by any of a variety of well known techniques including gravity feed systems, and pneumatic or mechanical injection systems. Injection molding is the most preferred technique because of the fluidity and low processing temperatures of the mixtures. The latter feature, low processing temperatures, is especially attractive in reducing the thermal cycling (thus increasing mold life) to which molds of the injection equipment are subjected.
A wide range of molding pressures may be employed. Generally, the molding pressure (hydraulic) is between about 100 psi and about 2000 psi, although higher or lower pressures may be employed depending upon the molding technique used. Most preferably, the molding pressure is in the range of about 300 psi to about 800 psi.
The mold temperature must, of course, be at or below the gel point of the gel forming material in order to produce a self supporting body. The appropriate mold temperature can be achieved before, during or after the mixture is supplied to the mold. Ordinarily, the mold temperature is maintained at less than about 40° C., and preferably is between about 15° C. and about 25° C. Thus, for example, it is expected that optimum production rates would be achieved with an injection molding process wherein the preferred gel forming materials (which exhibit gel points between about 30° C. and about 45° C.) are employed to form a mixture, and wherein the mixture is injected at less than 100° C. into a mold maintained at about 25° C. or less.
After the part is molded and cooled to a temperature below the gel point of the gel forming material, the green body is removed from the mold. The green body is then dried and placed directly into the furnace for firing.
In the furnace, the body is fired to produce the final product. The firing times and temperatures (firing schedules) ar regulated according to the powdered material employed to form the part. Firing schedules are well known in the art for a multitude of materials and need not be described herein. Because of the use of the novel molding composition of the present invention, no supporting materials are required during firing. Ordinarily for wax based systems, an absorbent, supporting powder is employed to assist in removing the wax from the part and to aid in supporting the part so that the intended shape of the product is maintained during firing. The present invention eliminates the need for such materials.
The fired products produced by the present invention result in very dense, net or near net shape products.
The following examples are presented in order to provide a more complete understanding of the invention. The specific techniques, conditions, materials and reported data set forth to illustrate the invention are exemplary and should not be construed as limiting the scope of the invention.
EXAMPLES
Batch Formulations
In the examples, solids loading based on weight percent is on a free moisture basis. Weight percent solids includes all residual material after removal of volatiles at 80° C. The solids quoted for volume percent are based on the ceramic powders used in the formulation.
The raw materials used in Examples 1-7 are as follows:
Al 2 O 3 , Alcoa A-16SG
MgO, Fisher Scientific M-49
Glycerine, Fisher Scientific G-33
Darvan C , aqueous solution, Vanderbilt Laboratories
TMA 25% tetramethyl ammonium hydroxide aqueous solution, Alfa Inorganics Water, deionized Agar, S-100, Meer Corp.
EXAMPLE 1
A dispersion was formed in a sigma blender from 2500 g Al 2 O 3 , 2.5 g MgO, 480 g water, 4.59 g TMA solution, and 43.75 g Darvan C . To this mixture was added 36.56 g of agar and an additional 45.78 g of water. Following 1 hr. of mixing at room temperature, the contents were heated to 90° C. over a period of 45 min and mixed for an additional 15 min. The material was cooled to room temperature, shredded in a food processor (Hobart model KFP700) and analyzed for solids content. The solids content was 83.02% based on weight and 52.2% based on volume.
EXAMPLE 2
Formulation: 2500 g Al 2 O 3 , 2.5 g MgO, 60.25 g glycerine, 43.75 g Darvan C solution, 4.59 g TMA solution, and 41.02 g agar. Enough water was used to bring the total water in the system to 512.7 g. The ingredients, minus agar, were mixed in a heated sigma blender. Agar was added incrementally over a period of 130 min. The material temperature at the end of this period was 90° C. The batch was cooled to room temperature, removed from the blender, and shredded in the food processor to prepare feed for molding. The solids content was determined to be 84.5 wt % (51.2 vol %).
EXAMPLE 3
A batch was prepared as described in Example 2, except that the amount of glycerine and water equaled 60.25 g and 530.83 g, respectively. The solids content after the batch was shredded was 84.75±0.15% (two determinations), (51.6% by volume).
EXAMPLE 3A
To prepare a partial batch having slightly lower solids concentration, a portion of the shredded material from Example 3 was placed in a covered, shallow pan, misted with water, shaken for a short period of time and then allowed to equilibrate, undisturbed for 3 days. The final solids content was 83.35 wt % (49.6 vol %).
EXAMPLE 4
This formulation was prepared in the manner described in Example 3, except that glycerine was not used. The solids content of the material after shredding was 84.04% by weight and 53.8% by volume.
EXAMPLE 5
In this example, the ceramic powder was subjected to a pre-ball milling step before blending into a molding batch. The procedures used are as follows:
1536 g Al 2 O 3 , 512 g water, 15.36 g Darvan C solution, and 2.84 g TMA solution were added to a 2 gal polyurethane lined jar mill and ball milled using zirconia media for 6 hrs. The following additions were made: 500 g Al 2 O 3 and 5 g Darvan C solution, ball milling 30 min; 300 g Al 2 O 3 , 3 g Darvan C solution, ball milling 30 min; 200 g Al 2 O 3 , 2.5 g MgO, 2.0 g TMA solution, and ball milling continued to give overall total of 10 hrs.
Brookfield viscosity readings were determined on the ball milled suspension. The suspension contained 81.7% dry solids.
______________________________________Brookfield Viscosity(spindle no. 21 with small sample adaptor): RPM Viscosity, cP______________________________________ 100 246.25 50 365 20 650 10 1050______________________________________ PG,15
The ball milled suspension, minus 384 g, was transferred to the sigma blender, and heat and mixing were applied. 38.56 g agar were added. The material was blended for a total of 45 min. The material temperature reached 90° C. After cooling, the material was removed from the blender and shredded. The solids content was 82.89 wt % (52.0 vol %).
EXAMPLE 6
The formulation was prepared free of the Darvan C dispersant used in Examples 1-5. A mixture of 42.4 g agar and 530 g H 2 O was heated in a sigma blender to 91° C. 2500 g of Al 2 O 3 and 2.5 g MgO, pre-heated to 110° C., was added incrementally to the blender. Small amounts of water were added periodically to maintain good mixing. After the total quantity of Al 2 O 3 was charged, the material was cooled, removed and shredded. The solids content was 80.28±0.77 wt % (2 determinations). Before molding, the solids content was adjusted to 82.44 wt % (51.7 vol %) by allowing the material to stand in a shallow pan, exposed to the atmosphere under a cover containing holes.
EXAMPLE 7
This batch was prepared using ball milled alumina powder. The example illustrates that deagglomeration of the powder before making up a molding batch has a beneficial effect on densification.
Five hundred grams of Al 2 O 3 and 0.5 g MgO were ball milled together at 40 wt % solids at pH 10 (NH 4 OH) for 20 hrs. The sample was filtered and dried. The procedure was repeated to obtain 1000 g. This material is designated "pre-ball milled powder".
Preparation of the molding batch was continued as follows. A mixture containing 1918.02 g Al 2 O 3 , 1.91 g MgO, 33.59 g Darvan C solution, 3.55 g TMA solution, and 536.35 g water was ball milled in a 2 gal polyethylene jar containing ZrO 2 media for 20 hrs. The ball milled suspension was transferred to the sigma blender and 834.19 g of the pre-ball milled dry powder was added with 14.60 g Darvan C solution and 1.54 g TMA solution. The mixture was blended for 70 min, 32.88 g agar was added, and heat was applied. When the temperature reached 60° C., 13 g additional agar was added. Blending was continued until the temperature reached 90° C. The batch was cooled, removed from the blender and shredded to prepare injection molding feedstock. The solids concentration was 82.9 wt % (51.8 vol %).
SUMMARY OF INJECTION MOLDING
RUNS FOR EXAMPLES 1-7
Table 2 summarizes the molding of parts in the shape of an annular ring (dimensions 4.84 cm O.D.×3.70 cm I.D.×0.99 cm thickness) from the Al 2 O 3 batches in Examples 1-7. Molding was done on a Boy 15S injection molding machine. Certain of the molded parts, indicated by part number in Table 2 were carried through densification. Firing conditions were 1600° C./1 hr. Density was determined by buoyancy. A dashed line data entry means that the measurement was not made.
TABLE 2__________________________________________________________________________Conditions Temp, °C. Density,Ex. Part Part Nozzle/ Gauge Pressure Die g/cm.sup.3 ShrinkNo. No. Wt. g Barrel psi °C. Green Fired %__________________________________________________________________________1 8 19.87 75/80 500 19 2.28 3.86 15.3 13 19.93 75/85 500 15 2.29 3.89 14.9 18 19.83 75/85 500 17 -- 3.99 15.2 26 20.04 75/88 500 17 2.26 3.82 14.92 3 20.17 80/85 420 19 2.32 3.90 14.8 8 20.18 75/85 420 18 2.31 3.89 15.53 6 20.30 80/85 750 19 -- 3.89 15.1 9 20.32 80/85 950 19 -- 3.91 14.93A 9 -- 80/85 400 19 -- 3.89 15.7 20 -- 70/75 400 19 -- 3.91 15.44 17 19.75 78/83 600 19 -- 3.81 --5 5 19.62 75/80 400 19 -- 3.91 -- 7 19.66 75/80 400 19 -- 3.91 -- 11 19.69 78/83 400 19 -- 3.88 --6 6 -- 80/85 600 19 -- 3.90 -- 16 -- 75/80 600 19 -- 3.88 --7 7 23.22* 80/85 600 17 -- 3.97 -- 26 23.67* 80/85 800 17 -- 3.96 --__________________________________________________________________________ *These rings were not hollow. One face of the ring was filled with solid material.
EXAMPLE 8
A large batch of Al 2 O 3 injection molding feed was prepared by repeating the following formulation five times and blending the material from each preparation: 2500 g Al 2 O 3 , 2.5 g MgO, 62 g glycerine, 4.5 g TMA solution, 43.75 g Darvan C , 43.94 g agar. The water in the system amounted to 487.3 g. The ingredients, minus agar, were mixed for 1 hr. in the sigma blender. Agar was added incrementally while heating the batch to 90° C. Mixing was continued 15 min after the batch reached 90° C. The contents were cooled, removed from the blender and shredded. Small adjustments in the solids content of individual batches were made by misting the shredded material in a covered shallow pan and allowing time for equilibration. The solids content of the combined batches was 84.2 wt % (50.6 vol %).
The rheology of the batch was examined by torque rheometry (HBI System 90). The material exhibited a torque value of 78±5 m-g at 93° C. This batch was used to mold parts in the form of a stator component of a turbine engine. The dimensions of the stator (green) are 5.87 cm (longest dimension)×3.68 cm (widest dimension)×4.22 cm (height). The parts were allowed to dry in the open air and then fired at 1600° C./1 hr. The final density determined by the buoyancy method was 3.95 g/cm 3 .
EXAMPLE 9
This example describes the preparation of a molding batch from Y 2 O 3 -ZrO 2 .
Before preparing the batch, a supply of deagglomerated ceramic powder (composition 85.47 wt % ZrO 2 , 8.0 wt % Y 2 O 3 and 5.63 wt % Al 2 O 3 ) was prepared by ball milling. The powder was ball milled in a 2 gal polyurethane lined jar, using ZrO 2 media, at 50 vol % solids and pH 20 (NH 4 OH). The mean particle size of the suspension was 0.74 micron as determined by settling (Sedigraph 5000ET). The suspension was then filtered and dried. The following ingredients were mixed in the sigma blender for 1 hr.: 2850 g of the ball milled powder, 583.73 g water, 34.20 g Darvan C solution, and 6.27 g TMA solution. Initially, 30 g of agar was used in the mixture. The contents in the blender were heated to 85° C. and 12.6 g additional agar was added. Small amounts of water were added periodically to maintain good mixing. Total mixing time with the agar amounted to 1 hr. and the final temperature was 91.3° C. The material was cooled and shredded. The solids concentration was 82.6 wt % (44.6 vol %).
EXAMPLE 10
The following procedure was used to prepare a molding slip of silicon nitride. MgAl 2 O 4 (Baikowski S50CR AS4) was calcined at 1325° C./2 hrs. and then dry milled for 3 hrs. using ZrO 2 media and screened (250 mesh). The surface area of the treated powder was 13 m 2 /g..
A supply of deagglomerated Si 3 N 4 formulation was prepared from 3680 g Si 3 N 4 (Denka 9FW), 160 g pre-calcined MgAl 2 O 4 and 160 g Y 2 O 3 (Molycorp). The powders were wet milled in 2-propanol for 7 hrs., screened through a 20 mesh screen and evaporated to dryness.
The ball milled silicon nitride powder mixture was added to the sigma blender pre-heated to 95° C. The powders were mixed about 90 min with deionized water containing Daxad 34A9R and agarose (Seakem LE, FMC Corp) was added. The blender was shut off after the material temperature reached 90° C. and all of the agarose was incorporated. The formulation contained 1840 g Si 3 N 4 , 80 g MgAl 2 O 4 , 80 g Y 2 O 3 , 777.8 g H 2 O, 10.0 g Daxad 34A9 and 62.24 g agarose.
The material was removed at room temperature and shredded in the food processor. The solids content was 75.3 wt % (47.6 vol %). The silicon nitride batch was molded in the Boy 15S machine in forms consisting of annular rings, tensile test bars and rectangular bars. The parts were dried in the open air at room temperature and fired at 1765° C. under 1 atmosphere of nitrogen.
The following properties were measured on the parts.
Ring:
Green density 1.73 g/cm 3
Fired Properties:
Weight 11.59 g
Density (geometrical) 2.96 g/cm 3
O.D.×I.D×thickness=3.8456±0.014×2.9166±0.020×0.7941±0.004 cm (17.52±0.74% average shrinkage)
Rectanqular bar:
Green density 1.79 g/cm 3
Fired weight 7.79 g (5.23% loss)
Density (geometrical) 2.95 g/cm 3
Dimensions 10.283×1.0196×0.2519 thickness (average shrinkage 16.88±0.47%)
______________________________________Notebook References for the ExamplesExample Reference______________________________________1 A1735 P24 (Batch 3)2 A1735 P26 (Batch 4)3 A1735 P28 (Batch 5)4 A1735 P31 (Batch 6)5 A1735 P33 (Batch 7)6 A1735 P36 (Batch 9)7 A1735 P48 (Batch 17)8 A1735 P59 (Batch 21)9 A1735 P6910 A1735 P28______________________________________
Having thus described the invention in rather full detail, it will be understood that these details need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.
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A process for shaping parts from ceramic powder that comprises the steps of (1) forming a concentrated mixture in excess of 40% ceramic solids by volume, the mixture comprising ceramic powder, a gel forming material chosen from the class of polysaccharides known as "agaroids", and a gel forming material solvent and being formed in a blender that provides a shearing action and is heated to raise the temperature of the mixture to about 70° C. to 100° C.; and (2) molding the mixture at a temperature sufficient to produce a self-supporting structure comprising the powder and gel. The parts exhibit excellent green strength and are rapidly fired without cracking, distortion or shrinkage problems.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is related to provisional patent application No. 60/688,769, filed Jun. 8, 2005 entitled “Obtaining heterostructures with quantum dots by liquid-phase epitaxy for solar cells”, the details of which are hereby incorporated by reference, and the benefit of the earlier Jun. 8, 2005 filing date is claimed in accordance with 35 USC 119(e) (1).
DESCRIPTION
1. Field of the Invention
The present invention relates to a nanotechnology, pulse cooling of substrate (PCS) method enabling formation of III-V compound semiconductor low-dimensional slab and column-like features and also to a method of fabrication of variety of commercially viable optoelectronic and photonic devices based on III-V column materials structures.
2. Description of the Related Art
The method of liquid phase epitaxy (LPE) was developed at 1960 and had been a dominant method for production of semiconductor structures for lasers, power diodes, and photovoltaic devices. LPE had been used for the mass production worldwide until advent of generation of novel semiconductor devices demanding method of growing deep submicron structures with superior control over chemical composition, uniformity and growth rates.
Nowadays, major methods of [nano] low-dimensional embedded in semiconductor structures growth are Molecular Beam Epitaxy (MBE) and Metal Organic Chemical Vapor Deposition (MOCVD). These methods allow growing low dimensional features [with size less than 0.1 μm] with high degree of control of chemical composition and growth rates. High cost of technological equipment, specific defects in the structures manufactured by MBE and MOCVD technologies stimulate searching of alternative methods of their fabrication, particularly based on crystallization from a liquid phase.
SUMMARY OF THE INVENTION
The invention is essentially a method for growth of features with size at least in one direction less than 1 μm, for example nano-dimensional layers; two dimensional (2D), and three dimensional (3D) island matrix. Compared to MBE and MOCVD methods, PCS method allow obtaining higher density of islands (˜10 12 cm −2 ), lower defect density and higher growth rates.
Epitaxial growth of nano dimensional features was realized from III-V and IV column materials low-melting temperature solution-melts in slider-type cassette placed in quartz reactor in the atmosphere of pure hydrogen ( FIG. 1 ).
In one of the embodiments of the present invention using resistive heater, temperature T 1 in the reactor was maintained within the range of 300-500° C. during growth process. The on-axis as well as off-axis cut GaAs substrates were used for structures with 2D nano-dimensional island matrix growth.
The main steps of epitaxial growth method of the present invention are as follows:
a) solution-melt and substrate are heated up to the saturation temperature of solution-melt T 1 ; b) the working (growth) surface of the substrate is brought into contact with the solution-melt; c) back surface of the substrate is brought into contact with the heat-absorber (the temperature T p of which is lower than that of the substrate and solution-melt ΔT=T 1 −T p ) that creates the pulse cooling in the range of 0.5-15° C., the duration of the interval is 5×10 −2 −5 s and the speed of growing the fore front of the cooling pulse is in the range of 5×10 3 −0.5×10 3 ° C./s;
The heat-absorber temperature had been chosen so that an overcooling at crystallization front did not exceeded 5-9° C. to avoid homogeneous nucleation in liquid phase volume. After some time τ the heat-absorber was heated to the temperature T 1 , but during this time there was a cooling at the interface of the substrate and solution-melt, that resulted in crystallization of a dissolved in solution-melt material. The shape of the formed features in particular, low-dimensional layers, 2D and 3D island matrix depends on several factors, for example, stress between substrate and growing feature's material, substrate orientation, and concentration of the material in the solution-melt.
EXAMPLE 1
The Structure with Nano-Dimensional 2D Island Matrix
The Scanning Tunnel Microscopy (STM) images of InAs uncapped islands grown on (100) GaAs substrate at T 1 =400° C., ΔT=5° C. and heat-absorber thickness δ=0.3 cm from In solution-melt is presented in FIG. 2 . The observed surface density of islands is ˜10 12 cm −2 .
The photoluminescence (PL) spectra of this sample at 77K demonstrate variation in peak position in the 1.24<hv<1.26 eV range, FIG. 3 . Photons with energy of 1.25 eV correspond to photoluminescence from 7.8 nm InAs islands in GaAs. Seven times PL intensity increase is observed when excitation power increases from 5 mW to 20 mW. Further excitation power increase up to 2 W does not significantly effect PL peak position as well as intensity that prove presence of the quantum dots. The PL peak position measured at different spots on the sample was in the 10 meV range what correspond island size variation around 10%.
EXAMPLE 2
The structure with two populations of nano-dimensional islands grown simultaneously during one cooling pulse
FIG. 4 presents photoluminescence spectra of two samples. Sample 1 (curve 1) has been grown on (100) GaAs substrate cut 4 degrees off in [110] direction; Sample 2 (curve 2) has been grown on (100) on-axis substrate. Coincidence of long wavelength part of PL spectrum of the samples demonstrates that size distribution of “large” islands is identical for these two samples. At the same time PL spectrum of misoriented sample reveals island size distribution broadened towards smaller sizes featuring split peak. In this case misoriented substrate provided growth front consisting of two steps with different nucleation conditions that resulted in two “independent” populations of InAs islands. Resulting PL spectrum is a superposition of PL from this two populations of InAs islands each having its own Gaussian-like size distribution. The structures containing nano-dimensional islands grown on misoriented substrates can be utilized in photovoltaic devices or diodes due to wider range light absorption or emission; or achieving several specific wavelength light absorption or emission.
Additional advantages and features of the present invention are described in the following Appendix A, entitled “OBTAINING HETEROSTRUCTURES WITH QUANTOM DOTS BY LIQUID-PHASE EPITAXY FOR SOLAR CELLS”, published August, 2004 (World Renewable Energy Congress), the details of which are hereby incorporated by reference.
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The features with size at least in one direction 1 μm growth method was developed by modifying liquid phase epitaxy. Number of processes was developed where duration and amplitude of the cooling pulse at the substrate interface were chosen in order to form low-dimensional features before system return to the equilibrium condition. This method allows obtaining low-dimensional features with observed quantum effect such as quantum layers, dots and superlattices. The shape of the features strongly depends on substrate orientation, stress and growth conditions.
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This invention pertains to a process for the preparation of known therapeutic agents and to chemical intermediates useful therein.
BACKGROUND OF THE INVENTION
Compounds of the formula: ##STR1## in which Z 2 is hydrogen, methyl, or ethyl are broad spectrum antineoplastic agents, see published PCT Application WO 86/05181 and corresponding U.S. Pat. No. 4,684,653. N-(4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamic acid, which is representative, has been prepared previously through an eighteen step synthesis in which a 2-(protected amino)-4-hydroxy-6-[2-(4-carboxyphenyl)ethenyl]pyrido[2,3-d]pyrimidine is coupled with a diester of L-glutamic acid utilizing peptide condensation techniques. The resultant dialkyl N-(4-[2-(2-protected amino-4-hydroxypyrido[2,3-d]pyrimidin-6-yl)ethenyl]benzoyl)-L-glutamate is then hydrogenated, following which the protecting groups are removed [see Taylor et al., J. Med. Chem. 28:7, 914 (1985)].
DETAILED DESCRIPTION
The present invention involves a simplified process for the preparation of important intermediates useful in the synthesis of the foregoing compounds; in particular, intermediates of the formula ##STR2## wherein
R 1 is NHCH(COOR 2 )CH 2 CH 2 COOR 2 or OR 2 ;
R 2 is hydrogen or a carboxylic acid protecting group;
R 4 is hydrogen or an amino protecting group;
Z 1 when taken independently of Z 2 is hydrogen; and
Z 2 when taken independently of Z 1 is hydrogen, methyl or ethyl; or
Z 1 and Z 2 when taken together are a carbon-carbon bond.
A number of compounds falling within Formula I in which Z 1 is hydrogen and Z 2 is hydrogen, methyl or ethyl are known from PCT Application No. WO 86/05181; others wherein Z 1 and Z 2 are a carbon-carbon bond are novel and constitute part of the present invention.
The process involves the step of allowing an unsaturated compound (as hereinafter defined) to react with a haloaromatic compound (as also hereinafter defined) in the presence of a palladium catalyst. The reaction has a number of different embodiments but each of these has in common the use of an organopalladium reactant which is generated from a palladium complex and the haloaromatic compound and which reacts with the unsaturated compound.
The palladium complexes are those which have been employed previously in the reaction of aryl halides and allylic alcohols, as described for example by Melpoler et al., J. Org. Chem., 41, No. 2, 1976, 265; Chalk et al., J. Org. Chem., 41, No. 7, 1976, 1206; Arai et al., J. Heterocyclic Chem., 15, 351 (1978); Tamuru et al., Tetrahedron Papers, 10, 919 (1978) 919; Tetrahedron, 35, 329 (1979). Particularly useful are the palladium/trisubstituted-phosphine complexes of Sakamoto, Synthesis, 1983, 312; e.g., a trisubstituted-phosphine such as a triarylphosphine, as for example triphenylphosphine, or a trialkylphosphine; a palladium salt such as palladium acetate or a palladium halide such as palladium chloride; and a cuprous halide, such as cuprous iodide.
The reaction preferably is conducted in the presence of at least one molar equivalent of a secondary or tertiary amine which acts as an acid acceptor, as for example triethylamine, or diethylamine, and under an inert atmosphere, optionally in the presence of an inert polar solvent such as acetonitrile, dimethylformamide, N-methylpyrrolidone and the like. Particularly preferred is the use of acetonitrile which serves as a solvent not only for the reactants but also for the salt formed from the acid acceptor and acid generated. Moderately elevated temperatures, as for example from about 75° to 125° C., preferable at or below 100° C., generally are advantageous.
The following four embodiments utilize the foregoing palladium catalysts and differ in the nature of haloaromatic compound and unsaturated compound employed as the reactants. Haloaromatic compounds as herein used include halopyridines, fused halopyridines and halobenzoic acid derivatives. The unsaturated compound includes both alkenes and alkynes as well as pyridines, fused pyridines and benzoic acid derivatives substituted with an alkenyl or alkynyl group.
In a first embodiment, the haloaromatic compound is a pyridine of the formula: ##STR3## wherein Y is amino or a nucleofuge;
X is bromo or iodo; and
R 3 is alkyl of 1 to 4 carbon atoms.
The haloaromatic compound of Formula II is allowed to react with an unsaturated compound of the formula: ##STR4## wherein Z 1 when taken independently of Z 2 is hydrogen;
Z 2 when taken independently of Z 1 is hydrogen, methyl or ethyl; or
Z 1 and Z 2 when taken together are a carbon-carbon bond, and
Q is a trisubstituted silyl group or a benzoyl group of the formula: ##STR5## wherein R 1 is --NHCH (COOR 2 )CH 2 CH 2 COOR 2 or OR 2 ; and
R 2 is a carboxylic acid protecting group.
In a second embodiment, the haloaromatic compound is a fused pyridine of the formula: ##STR6## wherein R 4 is hydrogen or an amino protecting group and
X is bromo or iodo.
A compound of Formula IV is allowed to react with an unsaturated compound of Formula III, discussed above, in the presence of the palladium catalyst.
In a third embodiment, the haloaromatic compound is of the formula: ##STR7## wherein X is bromo or iodo;
R 1 is --NH--CH(COOR 2 )CH 2 CH 2 COOR 2 or OR 2 ; and
R 2 is a carboxylic acid protecting group;
and the unsaturated compound is a pyridine of the formula: ##STR8## wherein Y is amino or a nucleofuge;
Z 1 when taken independently of Z 2 is hydrogen;
Z 2 when taken independently of Z 1 is hydrogen, methyl or ethyl; or
Z 1 and Z 2 when taken together are a carbon-carbon bond; and
R 3 is alkyl of 1 to 4 carbon atoms.
In a fourth embodiment, a haloaromatic compound of Formula V above is allowed to react with a pyrido[2,3-d]pyrimidine of the formula: ##STR9## wherein R 4 is hydrogen or an amino protecting group;
Z 1 when taken independently of Z 2 is hydrogen; and
Z 2 when taken independently of Z 1 is hydrogen, methyl or ethyl; or
Z 1 and Z 2 when taken together are a carbon-carbon bond.
In the first embodiment set forth above when Q is the depicted 4-carboxyphenyl group, and in the third embodiment, there is produced a novel intermediate of the formula: ##STR10##
When allowed to react with guanidine the intermediates of Formula VIII are converted directly to a 2-amino-4-hydroyy-6-substituted-pyrido[2,3-d]pyrimidine of Formula I in which R 4 is hydrogen.
In the second and fourth embodiments, a compound of Formula I is formed directly.
In the above reactions, R 2 preferably is an alkyl group such as methyl, ethyl, sec.-butyl, t-butyl, or another known carboxylic acid protecting group such as nitrobenzyl, 4-methoxybenzyl, diphenylmethyl, trichloroethyl, 1-ethoxyethyl, 1-ethylthioethyl, and the like. When R 1 is the depicted glutamic acid residue (which will be of L-configuration), typically the compound will be a L-glutamic acid dialkylester such as the dimethyl, diethyl, or di-(tert.-butyl) ester.
The compounds of Formula II can be prepared by esterification of the known 1,2-dihydro-2-oxo-3-pyridine carboxylic acid, introduction of a 5-iodo or 5-bromo group through treatment with N-iodosuccinimide or N-bromosuccinimide to yield the 5-iodo- or 5-bromo-2-oxo-1,2-dihydro-3-pyridine carboxylate, respectively, and replacement of the 2-oxo group with a suitable nucleofuge; e.g., chlorination with phosphorus oxychloride. The term "nucleofuge" refers to a conventional leaving group which is replaced by nucleophilic reagents. [See Organic Chemistry, Morrison and Boyd, Allyn and Breur, 4th Edition, p 205]. Typical nucleofuges thus include chloro, bromo, iodo, an aryl or alkylsulfinyl or sulfonyl group of up to 10 carbon atoms, an arylthio or alkylthio group of up to 10 carbon atoms, mercapto, and alkoxy of up to 10 carbon atoms. Preferably Y is chloro. X may be bromo or iodo; iodo is preferred.
Compounds of Formula IV can be prepared through the condensation of 2,4-diamino-6-hydroxy-pyrimidine and a halomalonaldehyde, such as bromomalonaldehyde or iodomalonaldehyde, preferably bromomalonaldehyde.
Alternatively, compounds of Formula IV can be obtained from a pyridine of Formula II through treatment with guanidine in a manner analogous to that described above, followed by optional protection of the amino group, as for example by acylation.
Compounds of Formula VI and VII can be prepared from starting materials of Formulas II and IV, respectively, by utilization of an unsaturated compound of Formula III in which Q is a trisubstituted silyl protecting group, followed by hydrolysis of the silyl group.
The amino and carboxylic acid protecting groups discussed herein are those conventionally employed, as described for example by Greene in "Protective Groups in Organic Synthesis", John Wiley & Sons, Inc., 1981, and McOmie in "Protective Groups in Organic Chemistry", Plenum Press, 1983. Particularly preferred R 4 protecting groups are alkanoyl groups such as acetyl, propionyl, pivaloyl, and the like.
Catalytic hydrogenation of a compound of Formula I yields the corresponding 2-amino(or 2-protected amino)4-hydroxy-6-substituted-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidine of the formula: ##STR11## in which R 4 is hydrogen or an amino protecting group and R 1 and Z 2 are as defined above.
When in the compounds of Formula IX R 1 is --NH(COOR 2 )CH 2 CH 2 COOR 2 and Z 2 is hydrogen, the resulting product is a protected derivative of the known [N-(4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamic acid; e.g., diethyl N-(4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamate (or the protected amino derivative thereof), which then is subjected to hydrolysis or hydrogenolysis as previously described to remove the protecting groups and yield the known N-(4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamic acid.
Alternatively, if in the compounds of Formula IX, R 1 is --OR 2 in which R 2 is a carboxylic acid protecting group, the protecting group is removed in a known fashion, as for example hydrolysis with hydrogen chloride in nitromethane, to yield a 2-amino-4-hydroxy-5,6,7,8-tetrahydro-6-[2-(4-carboxyphenyl)ethyl]pyrido[2,3-d]pyrimidine of the formula: ##STR12##
Following protection of the 2-amino group, as for example conversion to the N-pivaloyl derivative, a compound of Formula IX in which R 1 is OH is then coupled with a protected glutamic acid derivative in the manner described in PCT application WO 86/05181. The coupling reaction utilizes conventional condensation techniques for forming peptide bonds, such as activation of the carboxylic acid through formation of the mixed anhydride, treatment with DCC, or use of diphenylchlorophosphonate.
The hydrogenation of a compound of Formula I to a compound of Formula IX or Formula X generates a chiral center at the 6-position of the 5,6,7,8-tetrahydropyrido[2,3-d]pyrimidine ring. If Z 2 is other than hydrogen, a second chiral center is generated in the course of hydrogenation. In one embodiment of the invention, the group R 1 in Formula I itself contains a chiral center and is in one of its chiral forms substantially free of the other. Thus R 1 can be the depicted L-glutamic acid group which itself is chiral. Alternatively, R 2 in the group --OR 2 in formula I is one enantiomeric form of a chiral group such as sec.-butyl, 2-methylbut-1-yl, 1-phenylethyl, (1R,2S)-(-)ephedrine, 1-hydroxyprop-2-yl, 1-ethoxyethyl, 1-ethylthioethyl, the residue of a chiral terpene alcohol such as (1S,2R,5R)(+)-isomenthol, (1R,2R,3R,5S)-(-)-isopinocampheol, (S)-perillyl alcohol, [(1S)-endo]-(-)-borneol, and the like. Use of a single chiral form of the protecting group R 2 yields a mixture of two diastereomers upon hydrogenation of a compound of Formula I in which Z 2 is hydrogen: ##STR13## where R 2* is a chiral form of R 2 substantially free of its enantiomer. The product of the hydrogenation is a mixture of two diastereomers which can be directly separated by taking advantage of their different solubility properties, thus eliminating the need for an independent separation step, as for example formation of a salt with a chiral acid.
Analogously if Z 2 is methyl or ethyl, use of a chiral R 2* group produces a mixture of four diastereomers, e.g., (R,R,R 2* ), (R,S,R 2* ), (S,S,R 2* ) and (S,R,R 2* ) which are similarly separated.
The residue of the chiral alcohol is then hydrolytically removed from the individual separated diastereomers and which in the form of the free carboxylic acid is then coupled with a protected glutamic acid derivative as previously discussed.
The following examples will serve to further typify the nature of this invention but the invention should not be construed as being limited to these embodiments.
EXAMPLE 1
Methyl 2-chloro-5-iodo-3-pyridinecarboxylate
A. Methyl 2-Oxo-1,2-dihydro-3-pyridinecarboxylate
A mixture containing 27.8 g of 1,2-dihydro-2-oxo-3-pyridinecarboxylic acid, 3.0 ml of concentrated sulfuric acid in 500 ml of methanol, and 300 ml of benzene are heated under reflux for 2.5 hours. A Dean-Stark trap is then attached, and the azeotrope collected is removed periodically in 25 ml fractions over a period of 28 hours. The remaining solvent is removed by evaporation under reduced pressure and the solid residue suspended in 500 ml of cold water. The suspension is filtered (from which unreacted starting material can be recovered) and the filtrate continuously extracted with methylene chloride. The extracts are concentrated under reduced pressure to yield the title compound as a white solid which, upon recrystallization from,,l 4 L..of benzene, yields 19.48 g (64%) of methyl 2-oxo-1,2-dihydro 3-pyridinecarboxylate: m.p. 148°-151° C.; NMR (DMSO-d 6 , 80 MHz) delta 3.72 (s, 3H), 6.25 (dd, 1H, J=7.1 Hz, J=6.3 Hz), 7.64 (dd, 1H, J=6.3 Hz, J=2.2 Hz), 8.03 (dd, 1H, J=7.1 Hz, J=2.2 Hz).
Ethyl 2-oxo-1,2-dihydro-3-pyridinecarboxylate is obtained in an analogous fashion utilizing ethanol in place of methanol.
B. Methyl 5-Iodo-2-oxo-1,2-dihydro-3-pyridinecarboxylate
A solution containing 19.48 g of methyl 2-oxo-1,2-dihydro-3-pyridinecarboxylate and 36.15 g of N-iodosuccinimide in 500 ml of anhydrous methylene chloride is heated at reflux under a nitrogen atomosphere in the dark for 48 hours. The reaction mixture is concentrated to 150 ml under reduced pressure and the solid which forms is collected by filtration and washed with small portions of cold methylene chloride and benzene to give 16.59 g (47%) of methyl 5-iodo-2-oxo-1,2-dihydro-3-pyridinecarboxylate as a pale yellowish solid. This material is sufficiently pure for the next reaction; its properties upon recrystallization from ethyl acetate are as follows: m.p. 190°-192° C.; NMR (DMSO-d 6 , 300 MHz) delta 3.71 (s, 3H), 7.93 (d, 1H, J=2.26 Hz), 8.10 (d, 1H, J=2.26 Hz), IR (KBr) 2500-3050 (broad), 1725, 1630, 1585, 1475, 1425, 1320, 1260, 1235, 1180, 1150, 1105, 1065, 965, 875 and 800 cm -1 M/S (279, M + ), 247, 127 and 93.
Anal. Calcd. for C 7 H 6 INO 3 : C, 30.13; H, 2.17; I, 45.48; N, 5.02. Found: C, 30.24; H, 2.22; I, 45.55: N, 4.87.
The filtrate is evaporated and the residue dissolved in 500 ml of methylene chloride. The organic solution is extracted with a 10% sodium thiosulfate solution, washed with a saturated sodium chloride solution, and dried over anhydrous sodium sulfate. The solution is concentrated under reduced pressure and the residue triturated with ethyl acetate and filtered to yield an additional 5.49 g (15%) of methyl 5-iodo-2-oxo-1,2-dihydro-3-pyridinecarboxylate.
Utilization of an equivalent amount of N-bromosuccinimide yields the corresponding methyl 5-bromo-2-oxo-1,2-dihydropyridine-3-carboxylate. m.p. 181°-182° C.; NMR (DMSO-d 6 , 300 MHz) delta 3.72 (s, 3H), 7.97 (d, 1H, J=2.80 Hz), 8.05 (d, 1H, J=2.80 Hz); IR (KBr) 2500-3200 (broad), 1735, 1700, 1665, 1595, 1545, 1480, 1440, 1370, 1190, 1160, 1120, 970, 900, and 800 cm -1 .
C. Methyl 2-Chloro-5-Iodo-3-pyridinecarboxylate Procedure 1: To a mixture containing 2.0 g of methyl 5-iodo-1,2-dihydro-3-pyridinecarboxylate, 1.6 g of diethylaniline, 1.64 g of benzyltriethylammonium chloride and 3.6 ml of distilled phosphorus oxychloride in 100 ml of dry acetonitrile are added 15 drops of water. The mixture is heated under reflux for 18 hours. After cooling the reaction mixture to room temperature, the solvent is removed under reduced pressure and the residue taken up in methylene chloride and extracted with water. The organic solution is dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue is chromatographed on a column of flash silica gel using methylene chloride as the eluent. Evaporation of the eluent yields a pale yellowish solid which is recrystallized from aqueous ethanol to give 1.1 g (52%) of methyl 2-chloro-5-iodo-3-pyridinecarboxylate as a white solid: m.p. 73°-73.5° C.; NMR (80 MHz, CDCl 3 ) delta 3.96 (s, 3H), 8.43 (d, 1H, J=2.3 Hz), 8.71 (d, 1H, J=2.3 Hz).
Procedure 2: To a solution containing 0.12 ml of dry dimethylformamide and 0.14 ml of distilled phosphorus oxychloride in 20 ml of anhydrous methylene chloride are added 0.28 g of methyl 5-iodo-1,2-dihydro-3-pyridinecarboxylate in one portion. The mixture is stirred at room temperature under a nitrogen atmosphere for 28 hours. Workup as described in Procedure 1 yields 0.13 g (43%) of recrystallized methyl 2-chloro-5-iodo-3-pyridinecarboxylate.
Analogously prepared is methyl 2-chloro-5-bromo-3-pyridinecarboxylate, m.p. 49°-50° C.; NMR (CDCl 3 , 300 MHz) delta 3.99 (s, 3H), 8.32 (d, 1H, J=2.86 Hz), 8.60 (d, 1H, J=2.86 Hz). Ethyl 2-chloro-5-iodo-3-pyridinecarboxylate and ethyl 2-chloro-5-bromo-3-pyridinecarboxylate can be prepared in the same fashion.
EXAMPLE 2
tert.-Butyl 4-Ethynylbenzoate
A. tert.-Butyl 4-Bromobenzoate
To a mixture of 5.5 g of dry tert.-butanol and 7.08 g of dry pyridine is added a solution of 9.79 g of 4-bromobenzoyl chloride in 20 ml of anhydrous methylene chloride. The mixture is stirred under nitrogen for 2 days. The reaction mixture is then diluted with methylene chloride, and the organic solution extracted with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residual oil is distilled under reduced pressure to give 8.9 g (70%) of tert.-butyl 4-bromobenzoate as a colorless oil: b.p. 91°-92° C./1.2 mm; NMR (CDCl 3 , 80 MHz) delta 1.59 (s, 9H), 7.53 (d, 2H, J=8.7 Hz); IR (neat) 2970, 1710, 1585, 1475, 1390, 1290, 1160, 1110, 1070, 845 and 745 cm -1 .
Anal. Calcd. for C 11 H 13 BrO 2 : C, 51.38; H, 5.09; Br, 31.08. Found: C, 51.41; H, 5.36; Br, 30.38.
B. tert.-Butyl 4-Ethynylbenzoate
A mixture containing 1.31 g of tert.-butyl 4-bromobenzoate, 1.0 g of trimethylsilylacetylene, 10 mg of palladium acetate and 15.6 mg of triphenylphosphine in 15 ml of anhydrous triethylamine is heated in a sealed container at 100° C. for 16 hours. After cooling to room temperature, the reaction mixture is diluted with methylene chloride and extracted with water. The organic solution is dried over anhydrous sodium sulfate and the solvent removed under reduced pressure. The dark residue is chromatographed as a column of flash silica gel using a 10% ethyl acetate-hexanes mixture as the eluent to give tert.-butyl 4-(trimethylsilylethynylbenzoate as a dark oil: NMR (CDCl 3 , 300 MHz) delta 0.26 (s, 9H), 1.59 (s, 9H), 7.49 (d, 2H, J=8.23 Hz), 7.91 (d, 2H, J8.23 Hz). This is dissolved in 20 ml of anhydrous methanol, and then treated with 0.1 g of anhydrous potassium carbonate. The mixture is allowed to stir at room temperature under nitrogen for 3 hours. The reaction mixture is diluted with methylene chloride, extracted with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue is distilled under reduced pressure (60°-70° C./0.1 mm to give 0.75 g (73% over 2 steps) of tert.-butyl 4-ethynylbenzoate as a white solid: m.p. 71.5°-72° C.; NMR (CDCl 3 , 80 MHz) delta 1.62 (s, 9H), 3.23 (s, 1H), 7.55 (d, 2H, J=8.11 Hz), 7.96 (d, 2H, J=8.11 Hz); IR (KBr) 3240, 2970, 2100, 1700, 1600, 1450, 1365, 1300, 1250, 1160, 1115, 1015, 845 and 765 cm -1 ; M/S 202 M + ), 187, 157, 146, 129, 101, 75 and 57.
Anal. Calcd. for Cl 13 H 14 O 2 : C, 77.20; H, 6.98 Found: C, 76.86; H, 6.79.
EXAMPLE 3
Methyl 5-(4-tert.-butoxycarbonylphenylethynyl)-2-chloro-3-pyridinecarboxylate
To a solution containing 0.53 g of methyl 2-chloro-5-iodo-3-pyridinecarboxylate and 0.4 g of tert.-butyl 4-ethnylbenzoate in 30 ml of triethylamine is added 0.19 g of triphenylphosphine, 0.06 g of palladium chloride, and 0.03 g of cuprous iodide. The mixture is heated under reflux under a nitrogen atmosphere for 4 hours. The solvent is removed under reduced pressure and the residue is subjected to radial chromatography on silica gel using methylene chloride as the eluent. The major fraction isolated from the plate contained 0.43 g (65%) of methyl 5-(4-tert.-butoxycarbonylphenylethynyl)-2-chloro-3-pyridinecarboxylate as a pale yellowish oil which crystallized on standing. A small portion of this material is recrystallized from hexanes: m.p. 123°-124° C.; NMR (CDCl 3 , 300 MHz) delta 1.63 (s, 9H), 4.00 (s, 3H), 7.61 (d, 2H, J=8.15 Hz), 8.02 (d, 2H, J=8.15 Hz), 8.33 (d, 1H, J=2.16 Hz), 8.67 (d, 1H, J=2.16 Hz); IR (KBr) 3050, 3000, 2970, 2210, 1730, 1700, 1600, 1530, 1420, 1360, 1325, 1285, 1255, 1220, 1160, 1060, 845 and 765 cm - ; M/S 373 (M + +2), 371 (M + ), 315, 298, 282 and 256.
Anal. Calcd. for C 20 H 18 ClNO 4 : C, 64.60; H, 4.88; Cl, 9.53; N, 3.77. Found: C, 64.87; H, 4.88; N, 3.77; Cl, 9.58.
EXAMPLE 4
2-Amino-4-hydroxy-6-(4-tert.-butoxycarbonylphenylethynyl)pyrido[2,3-d]pyrimidine
To a solution containing 0.11 g of sodium in 30 ml of anhydrous tert.-butanol is added 0.45 g of guanidine hydrochloride. After stirring the mixture at room temperature for 15 minutes, 0.35 g of methyl 5-(4-tert.-butoxycarbonylphenyl)ethynyl-2-chloro-3-pyridinecarboxylate is added in one portion. The mixture is heated under reflux under nitrogen for 4 hours, cooled, diluted with ethanol, and the solvent removed under reduced pressure. The residue is dissolved in water and filtered to remove a small amount of insoluble material. The filtrate is acidified with a 3N hydrochloric acid solution and the precipitate that forms is collected by filtration, washed with water, and dried under reduced pressure to give 0.15 g (44%) of 2-amino-4-hydroxy-6-(4-tert.-butoxycarbonylphenylethynyl)pyrido[2,3-d]pyrimidine as a pale yellowish solid: m.p. >260° C.; NMR (DMSO-d 6 , 80 MHz) delta 1.55 (s, 9H), 7.71 (d, 2H, J=8.6 Hz), 7.96 (d, 2H, J= 8.6 Hz), 8.36 (d, 1H, J=2.5 Hz), 8.73 (d, 1H, J=2.5 Hz).
EXAMPLE 5
2-Amino-4-hydroxy-6-(4-carboxyphenylethynyl)pyrido[2,3-d]pyrimidine
Thirty-four milligrams of 2-amino-4-hydroxy6-(4-tert.-butoxycarbonylphenylethynyl)pyrido[2,3-d]pyrimidine is added to 15 ml of nitromethane which has been saturated with hydrogen chloride gas at 0° C. The mixture is stirred for 1 hour. Anhydrous ether is added and the solid filtered to give 27.6 mg (62%) of 2-amino4-hydroxy-6-(4-carboxyphenylethynyl)pyrido[2,3-d]pyrimidine as a pale yellowish solid: m.p. >260° C.; NMR (DMSO-d 6 , 80 MHz) delta 7.71 (d, 2H, J=8.4 Hz), 8.00 (d, 2H, J=8 4 Hz), 8.40 (d, 1H, J=2.3 Hz), 8.75 (d, 1H, J=2.3 Hz).
EXAMPLE 6
2-Pivaloylamino-4-hydroxy-6-bromodopyrido[2,3-d]pyrimidine
A mixture of 21.72 g of 2-amino-4-hydroxy-6-bromopyrido[2,3-d]pyrimidine in 75 ml of pivalic anhydride is heated under reflux under a nitrogen atmosphere for 3 hours. The dark reaction mixture is cooled and anhydrous ether is added. The solid which forms is collected by filtration and dissolved in methylene chloride and the solution is filtered through silica gel in a sintered funnel. The silica gel pad is extracted with a 1% methanol:methylene chloride mixture. Evaporation of the filtrate gave 13.58 g (46%) of 6-bromo-2-pivaloylamino-5-deaza-4(3H)-pteridone as a pale yellowish solid. This material is sufficiently pure for the next reaction. A small amount of the solid was recrystallized from benzene: m.p. 258°-260° C.; NMR (CDCl 3 , 300 MHz) delta 1.36 (s, 9H), 8.33 (brs, 1H), 8.65 (d, 1H, J=2.65 Hz), 8.92 (d, 1H, J=2.65 Hz); IR (KBr) 3250, 3190, 3100, 1670, 1610, 1550, 1480, 1375, 1275, 1220, 1140, 1020, 950, and 815 cm -1 .
Anal. Calcd. for C 12 H 13 BrN 4 O 2 C, 44.32; H, 4.03; N, 17.33; Br, 24.58. Found: C, 44.56; H, 3.85; N, 17.30; Br, 24.38.
Similarly prepared from the corresponding iodo compound is 2-pivaloylamino-4-hydroxy-6-iodopyrido[2,3-d]pyrimidine in 54% yield; m.p. 272°-273° C.(CH 3 CN); NMR (CDCl 3 , 300 MHz) delta 1.36 (s, 9H), 8.29 (brs, 1H), 8.83 (d, 1H, J=2.32 Hz) 9.06 (d, 1H, J=2.32 Hz); IR (KBr) 3240, 3200, 3120, 2970, 1670, 1610, 1580, 1545, 1480, 1430, 1370, 1325, 1270, 1230, 1140, 1020, 950, 810, and 760 cm -1 .
Analogously, a mixture of 0.52 g of 2-amino-4-hydroxy-6-iodopyrido[2,3-d]pyrimidine and 0.03 g of 4-dimethylaminopyridine in 10 ml of acetic anhydride is heated under reflux under nitrogen for 3 hours. After cooling the reaction mixture to room temperature, anhydrous ether is added, and the reaction mixture filtered to give 0.52 g (87%) of 2-acetamido-4-hydroxy-6-iodopyrido[2,3-d]pyrimidine as a tan colored solid: m.p.>280° C.; NMR (DMSO-d 6 , 80 MHz) delta 2.18 (s, 3H), 8.67 (d, 1H, J=2.5 Hz), 9.02 (d, 1H, J=2.5 Hz); M/S 330 (M + ), 315 and 288.
EXAMPLE 7
Diethyl N-(4-ethynylbenzoyl)-L-glutamate
To a solution of 0.55 g of 4-ethynylbenzoic acid (obtained from tert.-butyl 4-ethynylbenzoate in 84% yield by hydrolysis with trifluoroacetic acid) in 50 ml of anhydrous ether and 25 ml of anhydrous tetrahydrofuran is added 1.58 ml of triethylamine. This is followed by 1.00 g of phenyl N-phenylphosphoramidochloridate. After stirring the reaction mixture at room temperature under nitrogen for 0.5 hour, 0.90 g of diethyl L-glutamate is added in one portion. The mixture is allowed to stir for another 8 hrs. After a workup, the residue is subjected to column chromatography using a 1% methanol:methylene chloride mixture as the eluent. The major fraction isolated from the column contained 0.68 g (54%) of diethyl N-(ethynylbenzoyl)-L-glutamate as an oil which slowly solidified: NMR (CDCl 3 , 300 MHz) delta 1.25 (t, 3H, J=6.9 Hz), 1.33 (t, 3H, J=6.9 Hz), 2.11°-2.60 (m, 4H), 3.23 (s, 1H), 4.09 (q, 2H, J=6.9 Hz), 4.27 (1, 2H, J=6.9 Hz), 4.80 (m, 1H), 7.12 (d, 1H, J=7.2 Hz), 7.59 (d, 2H, J=8.4 Hz), 7.81 (d, 2H, J=8.4 Hz); IR (KBr) 3330, 3280, 2990, 1735, 1640, 1520, 1380, 1200, 1105, 1020, 855, and 770 cm.sup. -1.
EXAMPLE 8
Diethyl N-[4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-ylethynyl)benzoyl]-L-glutamate
A mixture of 2.0 g of 6-bromo-2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidine, 2.1 g of diethyl N-(4-ethynylbenzoyl)-L-glutamate, 2.57 ml of triethylamine, 0.11 g of palladium chloride, 0.32 g of triphenylphosphine, and 0.05 g of cuprous chloride in 150 ml of acetonitrile is heated at reflux under nitrogen for 2.5 hours. The solid which forms upon first cooling to room temperature is collected by filtration, and washed with cold acetonitrile to yield 1.91 g of diethyl N-[4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-ylethynyl)benzoyl]-L-glutamate which is sufficiently pure for further processing. Chromatography on silica gel with 5% methanol:methylene chloride showing the following physical properties. m.p. >250° C.; NMR (CDCl 3 , 300 MHz) delta 1.25 (t, 3H, J=7.20 Hz), 1.33 (t, 3H, J=7.20 Hz), 1.36 (s, 9H), 2.14-2.62 (m, 4H), 4.14 (q, 2H, J= 7.20 Hz), 4.27 (q, 2H, J=7.20 Hz) 4.79-4.86 (m, 1H), 7.30 (d, 1H, J=8.40 Hz), 7.63 (d, 2H, J=8.25 Hz), 7.86 (d, 2H, J=8.25 Hz), 8.51 (brs, 1H), 8.64 (d, 1H, J=2.40 Hz), 8.97 (d, 1H, J=2.40 Hz), 12.2 (brs, 1H); IR (KBr) 3330, 3290, 2970, 1730, 1655, 1590, 1530, 1440, 1370, 1260, 1140, 1020, 965, 925, 850, 810, and 760 cm -1 ; 13 C-NMR (CDCl 3 , 75 MHz) delta 14.3, 27.1, 27.2, 30.7, 40.6, 52.7, 61.1, 62.0, 87.61, 92.71, 115.1, 117.3, 125.9, 127.4, 127.5, 132.0, 133.9, 138.7, 149.6, 157.8, 158.6, 160.5, 166.4 172.1, 173.5, 180.8.
Anal. Calcd. for C 30 H 33 N 5 O 7 : C, 62.60; H, 5.78; N, 12.35. Found: C, 44.56; H, 3.85; N, 17.30; Br, 24.38.
EXAMPLE 9
2-Pivaloylamino-4-hydroxy-6-ethynylpyrido[2,3-d]pyrimidine
To a solution of 1.47 g of 2-pivaloylamino-4-hydroxy-6-trimethylsilylethynylpyrido[2,3-d]pyrimidine in 100 ml of anhydrous tetrahydrofuran are added, under nitrogen and at 0° C., 4.75 ml of 1M tetrabutylammonium fluoride in tetrahydrofuran. After 5 minutes, the reaction mixture is allowed to warm to room temperature and then is stirred for 2 hours. The solvent is removed under reduced pressure and the residue passed through a small pad of silica gel eluting with a 1% methanol: methylene chloride solution. The filtrate is concentrated under reduced pressure, and the residue purified further by radial chromatography on silica gel. The major fraction isolated from the plate contained 1.20 g (100%) of 2-pivaloylamino-4-hydroxy-6-ethynylpyrido[2,3-d]pyrimidine as an off white solid: m.p. >250° C.; NMR (CDCl 3 , 300 MHz) delta 1.36 (s, 9H), 3.31 (s, 1H), 8.39 (brs, 1H), 8.60 (d, 1H, J=1.99 Hz), 8.49 (d, 1H, J=1.99 Hz); IR (KBr) 3300, 3200, 2980, 1670, 1620, 1550, 1470, 1445, 1380, 1325, 1280, 1240, 1140, 1025, and 970 cm -1 .
2-Pivaloylamino-4-hydroxy-6-trimethylsilylethynylpyrido[2,3-d]pyrimidine is prepared in 81% yield from 2-pivaloylamino-2-hydroxy-6-bromopyrido[2,3-d]pyrimidine and trimethylsilylacetylene analogously to Example 2B. m.p. >250° C.; NMR (CDCl 3 , 300 MHz) delta 0.29 (s, 9H), 1.35 (s, 9H), 8.36 (brs, 1H), 8.57 (d, 1H, J=2.45 Hz), 8.92 (d, 1H, J=2.45 Hz); IR (KBr) 3200, 2970, 2170, 1680, 1620, 1545, 1475, 1440, 1380, 1275, 1250, 1145, 930, and 845 cm -1 .
EXAMPLE 10
Diethyl N-(4-bromobenzoyl)-L-glutamate
To a mixture of 0.92 g of of 4-bromobenzoyl chloride and 1.0 g of diethyl L-glutamate in 50 ml to dry methylene chloride is added 1.16 ml of triethylamine. The reaction mixture is stirred overnight under nitrogen. After a standard workup, the methylene chloride solution is concentrated under reduced pressure, and the residue recrystallized from hexanes to give 0.68 g (46%) of analytically pure diethyl N-(4-bromobenzoyl)-L-glutamate as a white solid: m.p. 82.5°-83.5° C.; NMR (CDCl 3 , 300 MHz) delta 1.26 (t, 3H, J=6.9 Hz), 1.33 (t, 3H, J=6.9 Hz), 2.11°-2.60 (m, 4H), 4.14 (q, 2H, J=6.9 Hz), 4.27 (q, 2H, J=6.9 Hz) 4.78 (m, 1H), 7.14 (d, 1H, J=7.2 Hz), 7.61 (d, 2H, J=8.4 Hz), 7.73 (d, 2H, J= 8.4 Hz); IR (KBr) 3320, 2980, 1745, 1720, 1635, 1520, 1375, 1300, and 1200 cm -1 .
Anal. Calcd. for C 16 H 20 BrNO 5 : C, 49.75; H, 5.22; N, 3.63; Br, 20.69. Found: C, 49.70; H, 5.15; N, 3.65; Br, 20.90.
Diethyl N-(4-iodobenzoyl)-L-glutamate is prepared from 4-iodobenzoyl chloride and diethyl L-glutamate in 56% yield by the same method. m.p. 105°-106° C.; NMR (CDCl 3 , 300 MHz) delta 1.26 (t, 3H, J=7.2 Hz), 1.33 (t, 3H, J=7.2 Hz), 2.11-2.60 (m, 4H), 4.14 (q, 2H, J=7.2 Hz), 4.78 (m, 1H), 7.15 (d, 1H, J=7.2 Hz), 7.58 (d, 2H, J=8.4 Hz), 7.83 (d, 2H, J=8.4 Hz)
EXAMPLE 11
Diethyl N-4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidine-6-ylethynyl)benzoyl-L-glutamate
A mixture of 0.68 g of 2-pivaloylamino-4-hydroxy-6-ethynylpyrido[2,3-d]pyrimidine, 1.20 g of diethyl N-(4-iodobenzoyl)-L-glutamate, 0.35 ml of triethylamine, 0.04 g of palladium chloride, 0.139 of triphenylphosphine, and 0.02 g of cuprous iodide in 75 ml of acetonitrile is heated at reflux under nitrogen for 3.5 hours. The reaction mixture is cooled and the solid collected, triturated with ethyl acetate, and filtered. The solid is recrystallized from ethanol to yield diethyl N-4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-ylethynyl)benzoyl-L-glutamate. m.p. >250° C.; NMR (CDCl 3 , 300 MHz) delta 1.25 (t, 3H, J=7.20 Hz), 1.33 (t, 3H, J=7.20 Hz), 1.36 (s, 9H), 2.14-2.62 (m, 4H), 4.14 (q, 2H, J=7.20 Hz), 4.27 (q, 2H, J=7.20 Hz) 4.79-4.86 (m, 1H), 7.30 (d, 1H, J=8.40 Hz), 7.63 (d, 2H, J=8.25 Hz), 7.86 (d, 2H, J=8.25 Hz), 8.51 (brs, 1H), 8.64 (d, 1H, J=2.40 Hz), 8.97 (d, 1H, J=2.40 Hz), 12.2 (brs, 1H); IR (KBr) 3330, 3290, 2970, 1730, 1655, 1590, 1530, 1440, 1370, 1260, 1140, 1020, 965, 925, 850, 810, and 760 cm -1 ; 13 C-NMR (CDCl 3 , 75 MHz) delta 14.3, 27.1, 27.2, 30.7, 40.6, 52.7, 61.1, 62.0, 87.61, 92.71, 115.1, 117.3, 125.9, 127.4, 127.5, 132.0, 133.9, 138.7, 149.6, 157.8, 158.6, 160.5, 166.4 172.1, 173.5, 180.8.
Anal. Calcd. for C 30 H 33 N 5 O 7 : C, 62,60; H, 5,78; N, 12.35. Found: C, 44.56; H, 3.85; N, 17.30; Br, 24.38.
EXAMPLE 12
2-Pivaloylamino-4-hydroxy-6-(4-tert.-butoxycarbonylphenylethynyl)pyrido[2,3-d]pyrimidine
A mixture of 2.0 g of 2-pivaloylamino-4-hydroxy-6-bromopyrido[2,3-d]pyrimidine (prepared according to Example 6), 1.31 g of tert.-butyl 4-ethynylbenzoate, 2.57 ml of triethylamine, 0.11 g of palladium chloride, 0.32 g of triphenylphosphine, and 0.05 g of cuprous iodide in 150 ml of acetonitrile is heated at reflux under nitrogen for 2.5 hours. The reaction mixture is cooled to room temperature and then in an ice bath. The solid is collected and washed with small portions of cold acetonitrile to yield 1.91 g (69%) of 2-pivaloylamino-4-hydroxy-6-(4-tert.-butoxycarbonylphenylethynyl)pyrido[2,3-d]pyrimidine as a pale yellowish powder, which is sufficiently pure for the next reaction. A small sample of this solid, purified further by chromatography on silica gel using a 5% methanol:methylene chloride mixture as the eluent, had the following constants: m.p. >250° C.; NMR (CDCl 3 , 300 MHz) delta 1.37 (s, 9H), 1.63 (s, 9H), 7.61 (d, 2H, J=8.50 Hz), 8.02 (d, 2H, J=8.50 Hz), 8.42 (brs, 1H), 8.66 (slightly brs, 9.01 (slightly brs, 1H);IR (KBr) 3200, 2980, 1710, 1670, 1600, 1545, 1440, 1375, 1290, 1140, and 770 cm -1 .
Alternatively, a mixture of 0.15 g of 2-pivaloylamino-4-hydroxy-6-ethynylpyrido[2,3-d]pyrimidine, 0.16 g of tert.-butyl 4-bromobenzoate, 0.23 ml of triethylamine, 0.01 g of palladium chloride, 0.03 g of triphenylphosphine, and 0.01 g of cuprous iodide in 20 ml of acetonitrile is heated at reflux under nitrogen for 4 hours. Upon cooling, the reaction mixture is filtered to give 0.18 g of a brown solid, which is further purified by radial chromatography using a 5% methanol: methylene chloride solution as the eluent. The major fraction isolated from the plate contained a yellowish solid which was triturated with ethyl acetate to give 0.1 g (40%) of 2-pivaloylamino-4-hydroxy-6-(4-tert.-butoxycarbonylphenylethynyl)pyrido[2,3-d]pyrimidine, constants as above.
EXAMPLE 13
2-Pivaloylamino-4-hydroxy-6-(4-carbxyphenylethynyl)pyrido[2,3-d]pyrimidine
One gram of 2-pivaloylamino-4-hydroxy-6-(4-tert.butoxycarbonylphenylethynyl)pyrido[2,3-d]pyrimidine is added to 25 ml of nitromethane saturated with hydrogen chloride gas at 0° C. After stirring at 0° C., the reaction mixture is allowed to reach room temperature and stirred for an additional hour. The suspension is diluted with anhydrous ether and suction filtered. The collected solid is washed with ether, methanol, and ether again, and then dried under reduced pressure to give 0.81 g of 2-pivaloylamino-4-hydroxy-6-(4-carboxyphenylethynyl)pyrido[2,3-d]pyrimidine as a yellowish powder: m.p. >250° C.; NMR (CDCl 3 , 300 MHz) delta 1.25 (s, 9H), 7.72 (d, 2H, J=8.02 Hz), 7.98 (d, 2H, J=8.02 Hz), 8.52 (d, 1H, J=2.01 Hz), 9.01 (d, 1H, J=2.01 Hz); IR (KBr) 3420, 3000, 1725, 1680, 1425, 1405, 1360, 1250, 1130, 1020, and 800 cm.sup. -1.
Alternatively, 2-amino-4-hydroxy-6-[(4-carboxyphenyl)ethynyl]pyrido[2,3-d]pyrimidine, prepared as described in Example 5, is heated in refluxing pivalic anhydride according to the procedure of Example 6 to yield 2-pivaloylamino-4-hydroxy-6-[(4-carboxyphenyl)ethynyl]pyrido[2,3-d]pyrimidine.
EXAMPLE 14
Diethyl N-4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidine-6-ylethynyl)benzoyl-L-glutamate
To a solution of 0.09 g of 2-pivaloylamino-4-hydroxy-6-(4-carboxyphenylethynyl)pyrido[2,3-d]pyrimidine and 0.07 ml of N-methylmorpholine in 5 ml of dry N-methylpyrrolidone is added 0.09 g of phenyl N-phenylphosphoramidochloridate. After stirring the reaction mixture at room temperature under a nitrogen atmosphere for 20 minutes, 0.08 g of diethyl L-glutamate hydrochloride is added and the mixture stirred for another 24 hours. The solvent is removed by distillation under reduced pressure and the residue is partitioned between chloroform and water. The organic phase is dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue is subjected to repeated chromatography on silica gel using a 2% methanol:methylene chloride mixture as the eluent. The major fraction isolated contained 0.05 g (38%) of diethyl N-4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidine-6-ylethynyl)benzoyl-L-glutamat which has a m.p. >250° C., constants as reported in Examples 8 and 11.
EXAMPLE 15
Diethyl N-(4-[2-(2-pivaloYlamino-4 -hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamate
A mixture of 0.59 g of diethyl N-[4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-ylethynyl)benzoyl]-L-glutamate and 1.5 g of 59% palladium on charcoal in 30 ml of trifluoroacetic acid is hydrogenated at 53 psi at room temperature for 24.5 hours. The reaction mixture is diluted with methylene chloride and filtered through Celite. The solvent is removed under reduced pressure. The residue is redissolved in methylene chloride and extracted with a saturated sodium bicarbonate solution and dried over anhydrous sodium sulfate. The solvent is removed under reduced pressure and the residue chromatographed on silica gel using a 4% methanol:methylene chloride mixture as the eluent. Evaporation of the eluate yields 0.60 g (100%) of diethyl N-(4-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamate as a white solid: m.p. >250° C.; NMR (CDCl 3 , 300 MHz) delta 1.22 (t, 3H, J=7.20 Hz), 1.29 (s, 9H), 1.30 (t, 3H, J=7.20 Hz), 1.61-3.35 (m, 13 H), 4.11 (q, 2H, J=7.20 Hz), 4.23 (q, 2H, J=7.20 Hz), 4.77-4.84 (m, 1H), 5.15 (brs, 1H), 7.17 (d, 1H, J=7.50 Hz), 7.23 (d, 2H, J=8.10 Hz), 8.56 (brs, 1H); IR (KBr) 3400, 3280, 2980, 1735, 1630, 1570, 1460, 1390, 1350, 1310, 1200, 1155, 1025, 930, and 800 cm -1 .
Anal. Calcd. for C 30 H 3 7 N 5 O 7 : C, 61.73; H, 7.08; N, 12.00. Found: C, 44.56; H, 3.85; N, 17.30; Br, 24.38.
EXAMPLE 16
N-(4-[2-(2-amino-4hhydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamatic acid
A solution containing 0.53 g of diethyl N-(4-[2-(2-pivaloylamino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamate, 3 ml of a 1N sodium hydroxide solution in 50 ml of methanol is stirred at room temperature for 70 hours. The mixture is acidified with acetic acid and the solid which forms is filtered, washed with methanol, and dried under reduced pressure to give 0.20 g (50%) of the known N-(4-[2-(2-amino-4-hydroxy-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidin-6-yl)ethyl]benzoyl)-L-glutamatic acid.
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2-Amino-4-hydroxy-6-[2-(4-carboxyphenyl)alk-1-en-1-yl]pyrido[2,3,-d]pyrimidines and 2-amino-4-hydroxy-6-[2-(4-carboxyphenyl)alk-1-yn-1-yl]pyrido[2,3-d]pyrimidines are prepared through the reaction of a haloaromatic compound and an unsaturated compound in the presence of a palladium catalyst. The products are chemical intermediates for the preparation of antineoplastic agents.
A typical embodiment is the reaction of a protected 2-amino-4-hydroxy-6-ethynylpyrido[2,3-d]pyrimidine and an ester of 4-iodobenzoic acid.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of co-pending patent application Ser. No. 14/546,759, filed Nov. 18, 2014, which is a Continuation of patent application Ser. No. 14/014,690, filed Aug. 30, 2013, now U.S. Pat. No. 8,887,472, which is a Divisional of patent application Ser. No. 12/964,380, filed Dec. 9, 2010, now U.S. Pat. No. 8,528,294, which claims the benefit of priority under 35 §119(e) to U.S. Provisional Application No. 61/288,011, filed Dec. 18, 2009. The disclosures set forth in the referenced applications are incorporated herein by reference in their entireties.
TECHNICAL FIELD
[0002] The present disclosure relates to a panelized and modular system for constructing and assembling buildings.
BACKGROUND
[0003] A building's structure must withstand physical forces or displacements without danger of collapse or without loss of serviceability or function. The stresses on buildings are withstood by the buildings' structures.
[0004] Buildings five stories and less in height typically use a “bearing wall” structural system to manage dead and live load vertical forces. Vertical forces on the roof, floors, and walls of a structure are passed vertically from the roof to the walls to the foundation by evenly spreading the loads on the walls and by increasing the size and density of the framing or frame structure from upper floors progressively downward to lower floors, floor-to-floor. For ceilings and floor spans, trusses are used to support loads on the ceilings and floors and to transfer these loads to walls and columns.
[0005] Where vertical bearing elements are absent, for example at window and door openings, beams are used to transfer loads to columns or walls. In buildings taller than five stories, where the walls have limited capacity to support vertical loads, concrete and/or structural steel framing in the form of large beams and columns are used to support the structure.
[0006] Lateral forces(e.g., wind and seismic forces) acting on buildings are managed and transferred by bracing. A common method of constructing a braced wall line in buildings (typically 5 stories or less) is to create braced panels in the wall line using structural sheathing. A more traditional method is to use let-in diagonal bracing throughout the wall line, but this method is not viable for buildings with many openings for doors, windows, etc. The lateral forces in buildings taller than five stories are managed and transferred by heavy steel let-in bracing, or heavy steel and/or concrete panels, as well as structural core elements such as concrete or masonry stair towers and elevator hoistways.
[0007] There is a need for a panelized and modular system for constructing and assembling buildings without relying on concrete and/or structural steel framing, heavy steel let-in bracing, and heavy steel and/or concrete panels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a stud for use as a framing member in horizontal truss panels.
[0009] FIG. 2 illustrates a track for use as a framing member in horizontal truss panels; FIGS. 3 and 3.1 illustrate a V-Braced horizontal truss panel.
[0010] FIGS. 3 and 3.1 illustrate a V-Braced horizontal truss panel.
[0011] FIGS. 4, 4.1, and 4.2 illustrate various open horizontal truss panels.
[0012] FIG. 5 illustrates a truss for attachment to horizontal truss panels.
[0013] FIG. 6 illustrates a structural column assembly for attaching horizontal truss panels to one another.
[0014] FIGS. 7 and 8 show the manner of attaching a horizontal truss panel such as shown in FIGS. 3, 3.1, 4, 4.1, and 4.2 to the structural column assembly of FIG. 6 .
[0015] FIG. 8 illustrates another example three-dimensional view of an example building design and a user interface 804 for generating structural components for the building design.
[0016] FIG. 9 shows a unified horizontal truss panel wall line having open and V-braced horizontal truss panels in a Unified Truss Construction System (UTCS) wall line.
[0017] FIG. 10 illustrates the truss of FIG. 5 .
[0018] FIG. 11 shows the truss/stud hangar of FIG. 6 .
[0019] FIG. 12 illustrate a portion of the structural column assembly of FIG. 6 .
[0020] FIG. 13 illustrates trusses connected to horizontal truss panels.
[0021] FIG. 14 illustrates trusses connected to horizontal truss panels to form a UTCS open span assembly creating a wall line.
[0022] FIG. 15 illustrates a UTCS building section formed as an assembly of multiple floors of a UTCS structure.
[0023] FIG. 16 shows alignment of the structural column assemblies of FIG. 6 in a building.
[0024] FIG. 16 illustrates a three-dimensional view of an example unit design.
[0025] FIG. 17 illustrates a three-dimensional view and a two-dimensional view of the floor-to-floor sections of a section of this building.
[0026] FIG. 18 shows the transfer of forces to the structural column assemblies of FIG. 6 .
DETAILED DESCRIPTION
[0027] The Unified Truss Construction System (UTCS) disclosed herein is a unique, new, and innovative structural system for single and multistory buildings, based on standardized structural panels. The system employs a limited number of configurations of uniquely engineered, light gauge metal framed vertical wall panels(horizontal truss panels), light-gauge-metal floor and ceiling trusses, cold rolled square or rectangular steel tubing (structural columns), and unique connecting plates and clips.
[0028] Unlike conventional approaches to designing and engineering a building's structure, where many different assemblies (walls, columns, beams, bracing, strapping, and the fasteners that fasten them together) are employed to manage vertical live load and dead load forces, and lateral forces, UTCS manages these forces through a limited number of uniquely designed standardized horizontal truss panels, which are assembled with structural columns and trusses. This unique assembly of elements effectively supports and transfers vertical and lateral forces from the walls, floor, ceiling, and roof to UTCS' redundant and dense column system.
[0029] Accordingly, columns absorb these vertical and lateral forces such that UTCS is not a vertical bearing wall structural system and eliminates the need for “hot formed” structural steel (weighted steel or “red iron”) and concrete as part of a building's structural system.
[0030] UTCS framing members are made from specially designed computerized roll forming machines. These machines manufacture framing studs or members from cold rolled steel commonly referred to as “coiled steel.” Each stud is cut to size, pre-drilled for fastening screws, with countersinks at the assembly screw head area, pre-punched for chasing mechanical, electrical, and plumbing (“MEP”) assemblies and rough-ins, pre-punched for passing vertical and horizontal bracing, and labeled for assembly. The machines read stud specifications from CAD files.
[0031] Horizontal truss panels and the trusses used in UTCS are constructed with framing members roll formed from light gauge steel, such as 18 to 14 gauge steel, depending on building height and code requirements. There are two profiles of framing members used in the horizontal truss panels, a stud 10 illustrated in FIG. 1 and a track 12 illustrated in FIG. 2 . The stud 10 and the track 12 are each rolled from light gauge steel, such as 18 to 14 gauge steel.
[0032] Each of the stud 10 and the track 12 includes a web 14 , flanges 16 , and lips 18 formed as illustrated in FIG. 1 . The flanges 16 extend in the same direction at substantially right angles from opposing sides of the web 14 , and the lips 18 extend inwardly from ends of the flanges 16 such that the lips 18 parallel the web 14 . The stud 10 and the track 12 differ mainly in that the flanges 16 of the track 12 are slightly higher than the flanges 16 of the stud 10 , and the web 14 of the track 12 is slightly wider than the web 14 of the stud 10 . These relative dimensions allow the stud 10 to slide into or through the track 12 without the need to compress the flanges 16 of the stud 12 , which affects its structural performance.
[0033] UTCS employs a limited number, such as two, configurations of horizontal truss panels. These horizontal truss panels are the structural wall elements of UTCS. If only two such configurations are used, they are (a) a V-braced horizontal truss panel 20 / 22 shown in FIG. 3 or FIG. 3.1 , which contains a “V” shaped brace (“V-brace”), and (b) an open horizontal truss panel 24 shown in FIG. 4 , which does not contain a V-brace.
[0034] An open horizontal truss panel 24 is generally used in any area of a building having large openings (windows, doors, pass-throughs, and the like) in a UTCS structure. The open horizontal truss panel 24 is engineered to support and transfer vertical live (occupancy, for example) and dead load forces (e.g., drywall, MEP assemblies, insulation, and the like) from floor and ceiling assemblies attached either to or proximate to each panel within a building (“Local Forces”). The V-braced horizontal truss panel 20 / 22 is engineered to support vertical local forces and lateral forces acting on the structure (wind and seismic, for example).
[0035] As shown in FIG. 3 , the V-braced horizontal truss panel 20 has a top track 26 and a bottom track 28 . Inboard of the top track 26 is a continuous horizontal brace comprised of back-to-back (web-to-web) tracks 30 and 32 , (referred to as double horizontal bracing), which are anchored by fasteners 34 such as bolts or screws to side studs 36 and 38 at the sides of the V-braced horizontal truss panel 20 . The top track 26 and the bottom track 28 are also anchored by fasteners 34 to the side studs 36 and 38 . The area between the continuous horizontal brace formed by the tracks 30 and 32 and the top track 26 contains vertical angled webbing 40 made from studs. This braced area in FIG. 3 acts as a truss attachment area 42 within the V-braced horizontal truss panel 20 for the attachment of trusses 106 discussed below, and supports and transfers forces exerted on the V-braced horizontal truss panel 20 to the structural columns discussed below and attached to each of the side studs 36 and 38 of the V-braced horizontal truss panel 20 .
[0036] The V-braced horizontal truss panel 20 also has two inboard studs 44 and 46 and a center stud 48 anchored by fasteners 34 to the top and bottom tracks 26 and 28 and to the tracks 30 and 32 . The side studs 36 and 38 pass through end cutouts 50 in the ends of the web 14 and in the lips 18 of the tracks 30 and 32 such that the flanges 16 of the studs 36 and 38 abut the flanges 16 at the ends of the tracks 26 , 28 , 34 , and 36 . These end cutouts 50 are shown in FIG. 2 . The fasteners 34 are at these abutment areas. Similarly, the inboard studs 44 and 46 and the center stud 48 pass through interior cutouts 52 of the webs 14 and lips 18 of the tracks 30 and 32 such that an exterior of the flanges 16 of the studs 36 and 38 and of the center stud 100 abut the interior of the flanges 16 of the tracks 26 , 28 , 34 , and 36 . These interior cutouts 52 are also shown in FIG. 2 . The fasteners 34 are at these abutment areas. The five vertical studs 36 , 38 , 44 , 46 , and 48 , for example, may be spaced 24″ on center. The point at which the inboard studs 44 and 46 and the center stud 48 pass through the tracks 30 and 32 is a hinge connection (i.e., a single fastener allows for rotation). The studs of the V-braced horizontal truss panel 20 also serve to support drywall, conduit, wiring, plumbing assemblies, etc.
[0037] The V-braced horizontal truss panel 20 also contains a continuous V-shaped bracing. This V-Bracing is unique in its design and engineering. The two legs of the V-brace are V-brace studs 54 and 56 such as the stud 10 shown in FIG. 1 . The V-brace stud 54 is anchored to the side stud 36 just below the tracks 30 and 32 and to the bottom track 28 by the fasteners 34 and passes through an interior cutout 58 in the web 14 of the inboard stud 44 . This interior cutout 58 is shown in FIG. 1 . The web 14 of the V-brace stud 54 abuts one flange 16 of each of the studs 36 and 44 and the track 28 . These abutment areas receive the fasteners 34 as shown.
[0038] Similarly, the V-brace stud 56 is anchored to the side stud 38 just below the tracks 30 and 32 and to the bottom track 28 by the fasteners 34 and passes through the interior cutout 58 in the inboard stud 46 . The web 14 of the V-brace stud 56 abuts one flange 16 of each of the studs 38 and 46 and the track 28 . These abutment areas receive the fasteners 34 as shown.
[0039] The attachment of the V-brace studs 54 and 56 to the studs 36 and 38 and to the track 28 require that the ends of the V-brace studs 54 and 56 be angles as shown in FIG. 3 . These angled ends permit multiple fasteners 34 to be used to anchor the V-brace studs 54 and 56 to their corresponding side studs 36 and 38 .
[0040] The V-brace studs 54 and 56 are positioned with their webs perpendicular to the webs of the studs 36 , 44 , 48 , and 38 of the V-braced horizontal truss panel 20 . Also, the V-brace studs 54 and 56 run continuously from immediately below the tracks 32 and 34 through the inboard studs 44 and 46 to the apex of a “V” at substantially the middle of the bottom track 28 . The connection at the apex of the V-bracing is facilitated by an apex plate 60 and additional fasteners 34 , which interconnect the V-brace studs 54 and 56 and the center stud 48 . The plate 60 , the bottom track 28 , and the stud 48 and the V-brace studs 54 and 56 are interconnected by the lower three fasteners as shown in FIG. 3 . The inboard stud 46 is also attached by fasteners 34 to the top track 26 and to the tracks 30 and 32 at the point where the inboard stud 46 passes through the interior cutouts 52 in the tracks 30 and 32 . The apex plate 60 may be formed from a material such as 18-14 gauge cold roll steel.
[0041] The connections of the V-brace studs 54 and 56 , to the side studs 36 and 38 , to the center stud 48 , and to the track 28 are moment connections and improve the lateral structural performance of the V-braced horizontal truss panel 20 .
[0042] These connections facilitate the transfer of most of the lateral forces acting on the V-braced horizontal truss panel 20 to the structural column of the system (discussed in further detail below).
[0043] The V-braced horizontal truss panel 20 also contains a track 62 providing horizontal bracing. The track 62 is located, for example, mid-way in the V-Brace formed by the V-brace studs 54 and 56 . The track 62 has the end cutouts 50 to accommodate the inboard studs 44 and 46 , has the interior cutout 52 to accommodate the center stud 48 , and is anchored by fasteners 34 to the inboard studs 44 and 46 and to the center stud 48 . The track 62 contributes to the lateral-force structural performance of the V-braced horizontal truss panel 20 .
[0044] The V-braced horizontal truss panel 20 may contain other bracing and backing as necessary for building assemblies like drywall, cabinets, grab bars and the like. The V-braced horizontal truss panel 20 is used as both interior (demising and partition) structural walls and exterior structural walls. The V-braced horizontal truss panel 20 / 22 may also accommodate windows and pass-throughs, although the space is limited as can be seen from the drawings.
[0045] The V-braced horizontal truss panel 22 of FIG. 3.1 has the same construction as the V-braced horizontal truss panel 20 of FIG. 3 except that the V-brace stud 54 forming half of the V-brace of FIG. 3 is replaced by two studs 64 and 66 whose lips 18 abut one another, and the V-brace stud 56 forming the other half of the V-brace of FIG. 3 is replaced by two studs 68 and 70 that may or may not abut one another. Thus, the studs 64 , 66 , 68 , and 70 form a double V-brace for the V-braced horizontal truss panel 22 of FIG. 3.1 to provide extra strength.
[0046] As shown in FIG. 4 , the open horizontal truss panel 24 has a top track 80 and a bottom track 82 . Inboard of the top track 80 is a continuous horizontal brace comprised of back-to-back (web-to-web) tracks 84 and 86 , (referred to as double horizontal bracing), which are anchored by fasteners 34 such as bolts or screws to side studs 88 and 90 at the sides of the open horizontal truss panel 24 . The top track 80 and the bottom track 82 are also anchored by fasteners 34 to the side studs 88 and 90 . The area between the continuous horizontal brace formed by the tracks 84 and 86 and the top track 80 contains vertical angled webbing 92 made from studs. This braced area in FIG. 4 acts as a structural truss 94 for the open horizontal truss panel 24 , and supports and transfers forces exerted on the open horizontal truss panel 24 to the structural columns discussed below and attached to each of the side studs 88 and 90 of the open horizontal truss panel 24 .
[0047] The open horizontal truss panel 24 also has two inboard studs 96 and 98 and a center stud 100 anchored by fasteners 34 to the top and bottom tracks 80 and 82 and to the tracks 84 and 86 . The side studs 88 and 90 pass through end cutouts 50 in the ends of the web 14 and of the lips 18 of the tracks 84 and 86 such that the flanges 16 of the studs 88 and 90 abut the flanges 16 at the ends of the tracks 80 , 82 , 84 , and 86 . These end cutouts 50 are shown in FIG. 2 . The fasteners 34 are at these abutment areas. Similarly, the inboard studs 96 and 98 and the center stud 100 pass through interior cutouts 52 of the webs 14 and of the lips 18 of the tracks 84 and 86 such that the flanges 16 of the studs 96 and 98 and of the center stud 100 abut the flanges 16 of the tracks 80 , 82 , 84 , and 86 . These interior cutouts 52 are also shown in FIG. 2 . The fasteners 34 are at these abutment areas. The five vertical studs 88 , 90 , 96 , 98 , and 100 , for example, may be spaced 24″ on center. The point at which the inboard studs 96 and 98 and the center stud 100 pass through the tracks 84 and 86 is a hinge connection (i.e., a single fastener allows for rotation). The studs of the open horizontal truss panel 24 also serve to support drywall, conduit, wiring, plumbing assemblies, etc.
[0048] The open horizontal truss panel 24 also contains a track 102 performing horizontal bracing. The track 102 is located, for example, mid-way between the tracks 82 and 86 . The horizontal bracing track 102 includes the end cutouts 50 through which the side studs 88 and 90 pass, has three interior cutouts 52 through which the inboard studs 96 and 98 and the center stud 100 pass, and is anchored by fasteners 34 to the side studs 88 and 90 , to the inboard studs 44 and 46 , and to the center stud 48 . The flanges 16 of the studs 88 , 90 , 96 , 98 , and 100 abut the flanges 16 of the track 102 . The fasteners 34 are applied to these abutment areas. The open horizontal truss panel 24 is engineered to handle vertical local forces.
[0049] The open horizontal truss panel 24 is designed to accommodate windows, doors, and pass-throughs. The open horizontal truss panel 24 , for example, may be 20′ wide or less.
[0050] FIGS. 4.1 and 4.2 illustrate open horizontal truss panels with one or more openings for windows, doors, and pass-throughs. FIG. 4.1 illustrates typical chase openings 104 through which MEP assemblies may be passed. These chase holes 104 may be formed in the V-braced horizontal truss panels 20 and 22 as well. FIG. 4.2 illustrates several open horizontal truss panels with openings for doors.
[0051] The open horizontal truss panel 24 may contain other bracing and backing as necessary for building assemblies like windows, doors, pass-throughs, drywall, cabinets, grab bars and the like. The open horizontal truss panel 24 is used as both interior (demising and partition) structural walls and exterior structural walls.
[0052] The horizontal truss panels described above are tall enough to accommodate the floor to ceiling areas of buildings, and to accommodate attachment of trusses, such as a truss 106 shown in FIG. 5 . The truss 106 is attached to the truss attachment area 42 and includes a top stud 108 and a bottom stud 110 interconnected by an angled webbing 112 made from studs such that the angled webbing 112 is attached to the top and bottom studs 108 and 110 by the fasteners 34 . The truss 106 is attached to the truss attachment area 42 of a horizontal truss panel 114 by use of truss/stud hangars 116 and the fasteners 34 . Although the horizontal truss panel 114 is shown as the V-braced horizontal truss panel 20 / 22 , the horizontal truss panel 114 can be any of the horizontal truss panels described herein. The truss/stud hangars 116 are discussed more fully below in connection with FIG. 11 .
[0053] The truss hangars 116 may be formed from a material such as 18-14 gauge cold roll steel.
[0054] The truss 106 is also shown in FIG. 10 . Trusses used in UTCS are made from the studs 10 . These trusses have the top and bottom studs 108 and 110 and the internal angled webbing 112 . The trusses 106 do not have side or end webbing connecting their top and bottom chords 108 and 110 . The truss 106 may be formed from light gauge steel, such as 18 to 14 gauge steel. The gauge and length of the truss 106 varies depending on application and width of floor span.
[0055] FIG. 6 illustrates a structural column assembly 130 that includes a structural column 132 having a top plate 134 and a bottom plate 136 welded to the top and bottom of the structural column 132 so that the top plate 134 covers the top of the structural column 132 and the bottom plate 136 covers the bottom of the structural column 132 . The structural column 132 , for example, may be four sided, may be hollow, and may vary in wall thickness depending on building height and code requirements. The top plate 134 and the bottom plate 136 are shown in FIG. 6 as being linear in the horizontal direction and are used where two walls are joined side-by-side so as to share a common linear horizontal axis. However, the top plate 134 and the bottom plate 136 may be “L” shaped plates when two walls are to be joined at a corner such that the horizontal axes of the two walls are perpendicular to one another.
[0056] One or more bolts 138 are suitably attached (such as by welding or casting) to the top plate 134 . The bolts 138 extend away from the top plate 134 at right angles. Each end of the bottom plate 136 has a hole 140 therethrough. Accordingly, a first structural column 132 can be stacked vertically on a second structural column 132 such that the bolts 138 of the top plate 134 of the second structural column 132 pass through the holes 140 of the bottom plate 136 of the first structural column 132 . Nuts may then be applied to the bolts 138 of the top plate of the second structural column 132 and tightened to fasten the first and second structural columns 132 vertically to one another.
[0057] The top and bottom plates 134 and 136 are slightly wider than the track 12 used for the horizontal truss panel 20 / 22 / 24 and vary in thickness depending on building height and code requirements. The through-bolting provided by the bolts 138 and holes 140 permit the structural columns 132 to be connected to one another vertically and to other assemblies within a building (roof, foundations, garages, etc.).
[0058] The structural columns 132 are connected to horizontal truss panels 20 / 22 / 24 by way of stud sections 142 of the stud 10 . The stud sections 142 are welded or otherwise suitably fastened to the top and bottom of the structural column 132 . A stud section 144 is fastened by weld or suitable fastener at about the middle of the structural column 130 such that its web 14 faces outwardly. This stud section 144 is a “hold-off” to keep the studs 36 , 38 , 88 , and 90 of the horizontal truss panels from deflecting. Unification plates such as 154 may or may not be used at this location.
[0059] The material of the structural column 132 , for example, is cold rolled steel. The structural column 132 may be hollow and have a wall thickness that varies depending on application and code. The material of the plates 134 and 136 and for the truss hangars 144 and 146 , for example, may be 18-14 gauge cold roll steel.
[0060] FIGS. 7 and 8 show the manner of attaching a horizontal truss panel such as the horizontal truss panels 20 , 22 , and 24 to the structural column assembly 130 . A unified horizontal truss panel is created when the structural column assembly 130 is attached to the horizontal truss panel 20 / 22 / 24 using four truss hanger unification plates 150 , which have a stud insertion projection for attachment of the trusses 106 discussed in further detail below, and two flat unification plates 154 , all of which are attached by fasteners 34 to the side stud 36 and 38 of the horizontal truss panel 20 / 22 / 24 and the stud sections 142 . The stud sections 144 as shown in FIG. 7 act to “hold-off” studs 36 and 38 so that these studs do not deflect through the space between the side studs 36 and 38 and the structural column 132 . Unification plates such as 154 may or may not be used at this location.
[0061] In a UTCS structure, a section or length of wall is assembled by attaching a number (depending on wall length) of horizontal truss panels together using the structural column assemblies 130 . The open horizontal truss panels 24 are used as a wall section(s) in buildings where there are larger openings like windows, doors, and pass-throughs. The V-braced horizontal truss panels 22 / 22 are used as wall section(s) generally throughout the rest of the structure so as to provide dense lateral support of the structure. FIG. 9 shows a horizontal truss panel wall line having open and V-braced horizontal truss panels 24 and 20 / 22 in a UTCS wall line.
[0062] As indicated above, the truss 106 is attached to the horizontal truss panel 20 / 22 / 24 by way of the truss/stud hangars 116 and the fasteners 34 located at the inboard studs 44 and 46 and the center stud 48 . The truss/stud hangar 116 is shown in FIG. 11 and includes a stud insertion projection 152 to be received within the top stud 108 of the truss 106 as illustrated in FIG. 5 and, when inverted 180 degrees as illustrated in FIGS. 5 and 8 , within the bottom stud 110 of the truss 106 . The truss/stud hanger 116 also includes L-shaped flanges 172 used to fasten the truss/stud hangers to the top track 26 and, inverted, to the horizontal bracing 30 and 32 of the horizontal truss panels.
[0063] The trusses 106 are connected to the horizontal truss panels 20 / 22 / 24 by inserting the end of the top stud 108 of the truss 106 into the insertion projection 152 and fastening by fasteners 34 , and connecting by fasteners 34 the L-shaped flanges 172 to the web 14 and flange 16 of the top track 26 and by connecting by fastener 34 a projection tab 176 of the truss hangar 116 to the top flange 16 of the stud 108 . The bottom stud 110 of the truss 106 is connected by inverting the truss/stud hanger 116 by 180 degrees, inserting the end of the bottom stud 110 of the truss 106 into the insertion projection 152 and fastening by fasteners 34 , connecting by fasteners 34 the L-shaped flanges 172 to the web 14 of the tracks 30 and 32 , and by connecting by fastener 34 the projection tab 176 to the bottom flange 16 of the stud 110 .
[0064] A truss 106 is also attached at each of the structural columns 132 by way of an insertion projection 152 on the unification plate 150 . The end of the top stud 108 of the truss 106 is inserted over the insertion projection 152 of the unification plate 150 and fastened with fasteners 34 to the web 14 of the stud 108 . The projection tab 176 is fastened by a fastener to the top flange 16 of the stud 108 . The bottom stud 110 of the truss 106 is connected by way of insertion of the end of the stud 110 over the insertion projection 152 of an unification plate 150 that is rotated 180 degrees. Fasteners 34 are used to connect the insertion projection 152 to the web 14 of the stud 110 . The projection tab 176 is attached by way of a fastener to the bottom flange 16 of the stud 110 .
[0065] FIG. 13 illustrates the trusses 106 connected to horizontal truss panels 20 / 22 / 24 .
[0066] FIG. 14 illustrates the trusses 106 connected to horizontal truss panels 20 / 22 / 24 forming a UTCS open span assembly where the horizontal truss panels 20 / 22 / 24 are assembled with the trusses 106 to create a wall line. The trusses 106 support a floor and ceiling assembly.
[0067] Attaching the trusses 106 to the horizontal truss panels in this manner incorporates the truss 106 into the horizontal truss panels 20 / 22 / 24 , eliminating the “hinge-point” that exists where a wall assembly sits on a floor, or where a ceiling assembly sits on top of a wall. This connection unifies the trusses 106 and horizontal truss panels 20 / 22 / 24 , in effect enabling the entire wall and floor system to act together as a “truss.” This configuration facilitates the transfer of forces on the floor, ceiling, and horizontal truss panels 20 / 22 / 24 to their attached structural column assemblies 130 . Accordingly, vertical and lateral forces are not transferred vertically horizontal truss panel to horizontal truss panel. When subflooring and drywall are incorporated into the building, the entire system acts as a “diaphragm.”
[0068] FIG. 15 illustrates a UTCS building section formed as an assembly of multiple floors of a UTCS structure. In a UTCS building or structure, the horizontal truss panels 20 / 22 / 24 are laid out such that the structural column assemblies 130 on one floor line up vertically with the structural column assemblies 130 on the floor below, and so on, down to a foundation.
[0069] FIG. 16 shows this alignment of the structural column assemblies. FIG. 16 also illustrates the density of the structural column assemblies 130 in a UTCS structure.
[0070] FIG. 17 illustrates a three-dimensional view and a two-dimensional view of the floor-to-floor joints of this assembly. It shows that horizontal truss panels 20 / 22 / 24 do not contact or bear on each other, as is otherwise typical in “bearing wall” and steel and concrete structures. The horizontal truss panels on one floor of a UTCS structure do not carry load from the floor above. This load is instead transferred to and carried by the structural column assemblies 130 . Each “floor” or elevation of the structure dampens and transfers its vertical live and dead load forces to the structural column assemblies 130 , where they are dampened and transferred vertically to the foundation of the building.
[0071] The V-braced horizontal truss panels 20 / 22 dampen and transfer the lateral forces acting on the building to the redundant structural column assemblies 130 in the structure. This transfer of forces is illustrated in FIG. 18 . The blow up portion of FIG. 18 also illustrates that the panels do not bear on each other vertically and that the forces (arrows) are not transferred vertically from one panel to the other. Rather the vertical and lateral forces are transferred laterally to the structural column assemblies 130 . This type of load transfer is facilitated by the unique design and assembly of the system. Both the horizontal truss panels 20 / 22 / 24 and the trusses 106 act as a unified truss system.
[0072] UTCS may employ horizontal truss panels of varying widths from 20′ to 2′, the most common being V-braced horizontal truss panels 20 / 22 measuring 8′ and 4′. These panels lead to a significant redundancy of the structural column assemblies 130 within the structure. Each open horizontal truss panel 24 acts to support and mitigate only those vertical local forces proximate to their attached structural column assemblies 130 . The V-braced horizontal truss panels 20 / 22 act to support vertical local forces as well as lateral forces acting on the structure. Because of the unique manner in which the horizontal truss panels 20 / 22 / 24 transfer vertical and lateral forces and the redundancy of the structural column assemblies 130 in the system, there in no need to configure panels differently from floor-to-floor. Only the width and gauge of the tracks 12 , the studs 10 , and V-brace vary, depending on building height and code requirements. Interior non-structural partition walls that separate spaces within a UTCS building are constructed from light gauge steel (typically 24-28 gauge) and are typical in Type I and Type II steel frame construction.
[0073] UTCS is extremely efficient in managing vertical and lateral forces on a building. With UTCS the need to build a bearing wall structure or heavy structural core is eliminated, vastly reducing costs over traditional construction practices. UTCS saves time as well because the structure of a building is erected from a limited number of pre-assembled panels. This also dramatically reduces the cost of engineering the structure of buildings.
[0074] UTCS is unique and innovative. It can be built on nearly any foundation system including slabs, structured parking, retail and commercial buildings. UTCS employs a framing technology that is based on a system-built, panelized approach to construction. UTCS uses panelized building technology and innovative engineering to significantly reduce the cost of design, material, and erection of a building. UTCS technology and engineering is a new structural system and method of assembling single and multistory buildings.
[0075] Certain modifications of the present invention have been discussed above. For example, although the present invention is particularly useful for constructing and assembling buildings without relying on concrete and/or structural steel framing, heavy steel let-in bracing, and heavy steel and/or concrete panels, it can also be applied to buildings having concrete and/or structural steel framing, heavy steel let-in bracing, and heavy steel and/or concrete panels. Other modifications will occur to those practicing in the art of the present invention.
[0076] Accordingly, the description of the present invention is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the appended claims is reserved.
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Structural truss panels include first, second, third, and fourth horizontal elongated members and first and second vertical elongated members fastened to the first, second, third, and fourth horizontal elongated members. The first and fourth horizontal elongated members form respectively a top and a bottom of the structural truss panel. The first and second vertical elongated members forming respective sides of the structural truss panel. The structural truss panel further includes and an angled webbing fastened between the first and second vertical elongated members and the first and second horizontal elongated members thereby creating an integrated web truss within the structural truss panel. The structural truss panel includes first, second, and third brace members forming a V-braced truss panel.
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FIELD OF THE INVENTION
The present invention relates to a wavelength tunable single-pass optical parametric amplifier, and more particularly to a wavelength tunable single-pass optical parametric amplifier by using the single pulse laser providing the pump and seed, which are required in the optical parametric amplification at the same time.
BACKGROUND OF THE INVENTION
Tunable ultrafast light sources are important for various spectroscopic and microscopic applications, such as the pump-probe spectroscopy, fluorescence lifetime imaging microscopy (FLIM), and multiphoton microscopy/spectroscopy. Many previous applications were based on a Kerr-lens mode-locked Ti:sapphire laser. However, the tuning range of a Ti:sapphire laser is limited to around 700 nm-1000 nm because of the laser gain bandwidth of the Ti:sapphire crystal. To extend the wavelength range of an ultrafast laser, supercontinuum generation (SCG) or optical parametric amplification (OPA) has been adopted.
The so called supercontinuum is a light source with an extra-wide bandwidth, and SCG is capable of extending input laser wavelengths into both shorter and longer wavelength directions about hundreds of nm. Thus, the purpose of extending the wavelength range is realized. However, as a result of extending of the wavelength, the pulse energy spreading in each wavelength range will be reduced in a corresponding way. Nevertheless, inasmuch as SCG redistributes the pump power into a wide wavelength range, the power density of SCG is typically less than 1 mW/nm. In addition, the strong chromatic dispersion in the fibers significantly lengthens the pulses, and subsequently degrades the applicability of the SCG because of the reduced peak power and poor temporal characteristics.
Both energy conservation and phase-matching condition have to be fulfilled when a shorter-wavelength pump wave is down-converted into a signal and an idler wave simultaneously. If a seed having the same wavelength with the signal or the idler is provided, the probability of conversion would be raised higher due to being excited, and thus the density of the output signal and idler were amplified. Since the wavelengths of the output signal and idler are different from that of the pump, thus the wavelengths can be extended, and the wavelengths are adjusted by changing the conditions of phase-matching condition. Generally speaking, it is hard to find a seed which is continuously tunable from ultraviolet to near-infrared, so the systems designed by the principle of optical parametric amplification are most likely complex and huge. In the conventional implementation, the conversion efficiency of such system is still low, and thus a high-energy, low-repetition rate pump source or an oscillator cavity is required to improve the conversion efficiency, in which the signal and the idler vibrate back and forth due to resonance to accumulate profits and reduce the pump threshold in the optical parametric conversion process.
In the above-mentioned methods, regardless of raising laser energy, lowering the repetition rate or setting the oscillator cavity, not only the high cost and complex system are problems, but also for some industries, the low repetition rate is insufficient to handle the requirements in use. However if not so, the conversion efficiency can not be raised effectively. It is in a dilemma for a person ordinarily skilled in the art.
In order to overcome the drawbacks in the prior art, a wavelength tunable single-pass optical parametric amplifier is provided. The particular design in the present invention not only solves the problems described above, but also is easy to be implemented. Thus, the present invention has the utility for the industry.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, a wavelength tunable single-pass optical parametric amplifier is provided. The single-pass optical parametric amplifier comprises a light source emitting a fundamental wave having a wavelength range; a nonlinear material, which the fundamental wave passes therethrough to form a second harmonic generation wave having a light path; a supercontinuum generator extending the wavelength range of the fundamental wave to form a supercontinuum generation seed; and an optical parametric wavelength transformer transforming the supercontinuum generation seed and the second harmonic generation wave into a signal wave and an idler wave.
Preferably, the single-pass optical parametric amplifier further comprises a dichroic mirror separating the fundamental wave and the second harmonic generation wave; and a translational stage controlling the light path of the second harmonic generation wave.
Preferably, the single-pass optical parametric amplifier further comprises a cold mirror making the supercontinuum generation seed and the second harmonic generation wave proceed in an identical path to pass through the optical parametric wavelength transformer; and a temperature controller controlling a temperature of the optical parametric wavelength transformer.
Preferably, the supercontinuum generation seed and the second harmonic generation wave pass through the optical parametric wavelength transformer at the same time, and the signal wave and the idler wave are amplified.
Preferably, the supercontinuum generation seed has a wavelength range covering at least one of wavelengths of the signal wave and the idler wave.
Preferably, the light source is a single mode-locked Yb:fiber laser device having 50 MHz repetition rate, 5 W average power and 1 ps pulse width.
Preferably, the nonlinear material comprises LiB 3 O 5 (LBO).
Preferably, the supercontinuum generator comprises a photonic crystal fiber.
Preferably, the optical parametric wavelength transformer comprises a nonlinear crystal which comprises magnesium oxide-doped periodically poled lithium niobate (MgO:PPLN) crystal.
Preferably, the supercontinuum generation seed has a wavelength range between 550 nm to 1900 nm.
In accordance with another aspect of the present invention, a method for transforming a laser wave is provided. The method comprises steps of providing the laser wave having a fundamental wave having a wavelength range; generating a second harmonic generation wave based on the fundamental wave; extending the wavelength range of the fundamental wave to form a supercontinuum generation seed; and transforming the second harmonic generation wave and the supercontinuum generation seed into a signal wave and an idler wave.
Preferably, the method further comprises a step after the step of generating a second harmonic generation wave: separating the fundamental wave and the second harmonic generation wave.
Preferably, the second harmonic generation wave and the supercontinuum generation seed are transformed into a signal wave and an idler wave via a way of quasi-phase-matching.
Preferably, the laser wave is a single mode-locked Yb:fiber laser having 50 MHz repetition rate, 5 W average power and 1 ps pulse width.
Preferably, generating the second harmonic generation wave is via frequency doubling the fundamental wave.
Preferably, the supercontinuum generation seed has a wavelength range covering at least one of wavelengths of the signal wave and the idler wave.
In accordance with a further aspect of the present invention, a single-pass optical parametric amplifier is provided. The single-pass optical parametric amplifier comprises a laser providing a fundamental wave having a wavelength range and a second harmonic generation wave; a supercontinuum generator extending the wavelength range of the fundamental wave to form a supercontinuum generation seed; and an optical parametric wavelength transformer transforming the supercontinuum generation seed and the harmonic generation wave.
Preferably, the single-pass optical parametric amplifier further comprises a dichroic mirror separating the fundamental wave and the second harmonic generation wave; and a cold mirror making the supercontinuum generation seed and the second harmonic generation wave proceed in an identical path to pass through the optical parametric wavelength transformer.
Preferably, the single-pass optical parametric amplifier further comprises a nonlinear material, which the fundamental wave passes therethrough to form a second harmonic generation wave due to frequency doubling and the nonlinear material comprises LiB 3 O 5 (LBO).
Preferably, the supercontinuum generation seed and the second harmonic generation wave are transformed into a signal wave and an idler wave via the optical parametric wavelength transformer.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed descriptions and accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the configuration of the single-pass optical parametric amplifier according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for the purposes of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed.
Please refer to FIG. 1 , which shows the configuration of the single-pass optical parametric amplifier according to a preferred embodiment of the present invention. The laser 10 is a device of a single mode-locked ytterbium-doped fiber laser (mode-locked Yb:fiber laser), which can emit a laser light with 1 ps pulse width, 1040 nm central wavelength, 5 W average energy, 50 MHz repetition rate and 100 nJ pulse energy. The laser light has a fundamental wave 101 which passes through a nonlinear material 11 . Under type I noncritical phase-matching, a 520 nm second harmonic generation wave 102 is formed due to frequency doubling. The repetition rate of the second harmonic generation wave 102 is 50 MHz, the same as that of the fundamental wave 101 . The pulse energy is 10 nJ. In this embodiment, the nonlinear material 11 uses a LiB 3 O 5 (LBO) nonlinear optical crystal.
After the laser light passes through the nonlinear material 11 , the second harmonic generation wave 102 is still mixed with the fundamental wave 101 . When both of them pass through the dichroic mirror, the second harmonic generation wave 102 is separated from the fundamental wave 101 . Next, the fundamental wave 101 passes through a supercontinuum generator 13 , which is a photonic crystal fiber. After the fundamental wave 101 is coupled with the supercontinuum generator 13 , the mechanism of the supercontinuum generation is formed, which substantially extends the wavelength range of the fundamental wave 101 to be a supercontinuum generation seed 103 . The extended wavelength range of the fundamental wave 101 is between 550 nm to 1900 nm.
In another side, the optical path of the second harmonic generation wave 102 is adjusted via a translational stage 14 . Since the wavelength of the fundamental wave 101 is different from that of the second harmonic generation wave 102 , and mediums for them to pass through in paths are different too, the optical path difference between the fundamental wave 101 and the second harmonic generation wave 102 may be generated. In order that the pulses in two waves can enter an optical crystal at the same time, the optical path difference in the present system is adjusted via the translational stage 14 .
Then, the supercontinuum generation seed 103 and the second harmonic generation wave 102 passing through the translational stage 14 flock together at a cold mirror 15 to make both of them back to an identical optical path to pass through a multi-channel magnesium oxide-doped periodically poled lithium niobate (MgO:PPLN) crystal, which can be viewed as an optical parametric wavelength transformer 16 . After the second harmonic generation wave 102 serving as a pump enters the optical parametric wavelength transformer 16 , it would be transformed into a signal 104 and an idler 105 whose wavelengths, 800 nm and 1600 nm respectively, are different from that of the harmonic generation wave 102 . At this time, the supercontinuum generation seed 103 serves as a seed. As a result of the principle of optical parametric amplification, the intensity of the signal 104 and the idler 105 can be amplified. Besides, due to the characteristic of the periodically poled crystal, the supercontinuum generation seed 103 and the harmonic generation wave 102 pass through the optical parametric wavelength transformer 16 via a way of quasi-phase-matching. This raises the conversion efficiency significantly.
Additionally, being a seed in the present invention, the supercontinuum generation seed 103 is generated from the fundamental wave 101 after supercontinuum generation, and the wavelength range thereof is extended to 550 nm to 1900 nm, covering the wavelength ranges of the signal 104 and the idler 105 . In other words, the supercontinuum generation seed 103 provides an effect of double seed for the signal 104 and the idler 105 respectively. Hence, the conversion efficiency of the optical parametric amplification can be greatly enhanced.
Since the purpose of the present invention is to provide a wavelength tunable single-pass optical parametric amplifier by using the single pulse laser to provide the pump and seed required in the optical parametric amplification, the output wavelength can be adjusted through changing the conditions of quasi-phase-matching of the pump, signal and idler. In other words, by choosing the channels of different grating periods in the periodically poled crystal to provide the pump input, the wavelengths of the transformed signal 104 and idler 105 can be adjusted accordingly. Besides, the crystal temperature of the wavelength transformer 16 itself can be controlled in a range of 30-200° C. via a temperature controller 17 . Therefore, accurate and detailed adjustment of the wavelength can be achieved. In the wavelength tunable single-pass optical parametric amplifier of the present invention, the adjustable wavelength range covers 700 nm to 1900 nm.
Moreover, since the laser of the present invention comes from a single laser, thus after providing the pump and seed required in the optical parametric amplification respectively, the condition of timing jitter between the pump and seed can be avoided. This can improve the stability of the system effectively. Basically, according to the system design of the present invention, under the conditions of not requiring the optical oscillator, the pulse repetition rate of up to 50 MHz, and only 10 nJ of the pulse energy of the second harmonic generation wave 102 serving as the pump, the conversion efficiency can reach 50%. Accordingly, the present invention is advanced and outstanding.
The optical materials used in the present invention basically are not limited to the crystal, laser or optical device mentioned in this embodiment. This embodiment is only an example of implementation; other materials having the same effect could also be substituted for the above-mentioned materials.
Based on the above, the present invention not only provides a wavelength tunable laser device having a large wavelength range, but under the conditions of not requiring the optical oscillator and saving the cost, the problem of low conversion efficiency resulting from the low pulse energy in the prior art can be effectively solved. Besides, the conditions of the time difference and instability conventionally generated from optical parametric amplification can also be avoided. Therefore, the present invention effectively solves the problems and drawbacks in the prior art, and thus it fits the demand of the industry and is industrially valuable.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
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A single-pass optical parametric amplifier is provided. The single-pass optical parametric amplifier comprises a light source emitting a fundamental wave having a wavelength range; a nonlinear material, which the fundamental wave passes therethrough to form a second harmonic generation wave having a light path; a supercontinuum generator extending the wavelength range of the fundamental wave to form a supercontinuum generation seed; and an optical parametric wavelength transformer transforming the supercontinuum generation seed and the second harmonic generation wave into a signal wave and an idler wave.
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CROSS-REFERENCE TO A RELATED APPLICATION
This application claims the benefit of U.S. provisional application Ser. No. 61/122,063, filed Dec. 12, 2008, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to a dry powder fibrin sealant.
BACKGROUND OF THE INVENTION
WO97/44015 describes a dry powder fibrin sealant based on micro-particles of fibrinogen and thrombin. This has been demonstrated to be an easy-to-use, stable and efficacious topical haemostat. The product can be used immediately, without reconstitution. On contact with aqueous fluid such as blood, the exposed active thrombin immediately converts the exposed fibrinogen into insoluble fibrin polymers.
SUMMARY OF THE INVENTION
The novel fibrin sealant is a blend of spray-dried fibrinogen and thrombin, each of which has been individually co-spray dried with an excipient. A number of excipients have been used in the fibrin sealant formulation to stabilise the active ingredients fibrinogen and thrombin and the physical stability evaluated. In addition, the fibrin sealant formulation has been exposed to electron beam/gamma irradiation or heat sterilisation in order to terminally sterilize the product. The results of the evaluation indicate that trehalose is the most effective excipient in terms of protein protection during stability storage and electron beam exposure. The superior stabilization afforded by the trehalose-based formulations may be attributed to the higher glass transition temperature of trehalose compared to other excipients such as sucrose.
The influence of different parameters on the efficacy of the product was determined in pig liver biopsy models and pig liver resection models. The efficacy of the fibrin sealant powder to stop severely bleeding injuries, with blood loss of >10 ml/min, was enhanced by the opportunity to apply pressure directly after administration of the product. Fibrin sealant powders with a fibrinogen content of at least 4% w/w and a thrombin content of at least 139 IU/g were shown to be effective in stopping severe bleeding. The optimum fibrinogen and thrombin content was ˜7.5% w/w and ˜400 IU/g, respectively. Fibrinogen and thrombin from 3 different suppliers all performed equally well, demonstrating the robustness of the product. Terminal sterilization of the product using electron beam or gamma irradiation of up to 15 or 25 kGy had no effect on the efficacy of the product and is considered to reduce the risk of bacterial contamination before use. In summary, the invention provides a fibrin sealant product that demonstrates high efficacy at low fibrinogen levels in severely bleeding wounds and can be terminally sterilized using standard irradiation methods.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of the particle size distribution of spray-dried thrombin:trehalose according to the invention.
FIG. 2 is a plot of the particle size distribution of spray-dried fibrinogen:trehalose according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Respective fibrinogen-containing and thrombin-containing soluble microparticles can be formulated together, in stable, dry form. This formulation can be subsequently activated, as desired, to give a fibrin sealant that is useful in wound therapy and surgical repair. It can meet the primary objectives of achieving good flow properties, enhanced, effective delivery to the active site, and dissolution only at the site, not in the delivery system.
The content of fibrinogen in the microparticles containing it may be about 0.1 to 50% w/w, preferably about 0.5 to 20 w/w. The content of thrombin in the microparticles containing it may be about 10 to 20,000 IU/g, preferably about 25 to 1,000 IU/g.
Microparticles comprising fibrinogen or thrombin may be prepared by the procedures described in WO92/18164, WO96/09814 and WO96/18388. These spray-drying and associated particle manipulation processes enable the production of soluble protein microcapsules with defined size distribution, e.g. of up to 50 μm in diameter. For example, as described in those documents, the microparticles may be produced reproducibly, e.g. with 90% or more (by volume) up to 30 μm, e.g. 10 to 20 μm, in size.
Microparticles of the invention are preferably prepared by spray-drying. Typically, a 2-fluid nozzle is used which utilises compressed air during the atomisation process; this results in the production of hollow microparticles. The maximum particle size (X50) of microparticles that can be manufactured using this atomisation system on the Niro Mobile Minor spray dryer is ˜30 μm. Preferred X50 values for the micoparticles of the invention are between 5 and 50 microns, most preferably between 10 and 20 microns.
Microparticles of the invention may be prepared by spray-drying a solution of the active component with trehalose alone. An alternative procedure comprises co-spray-drying, in which fibrinogen or thrombin and another wall-forming material are formulated and spray-dried, to give microparticles in which the active component is incorporated in the wall of the particle. The product is preferably amorphous or in the form of a glass, as measured by a suitable technique such as FTIR or DSC., with a glass transition temperature of at least 50 Celsius, most preferably at least 80 Celsius.
The fibrinogen or thrombin may be full-length or any active fragment thereof. Fragments are known; see Caller et al, J. Clin. Invest. 89:546-555 (1992). Fibrinogen raw material may be a frozen solution, although, lyophilised powder which requires reconstitution prior to spray-drying may be used.
Suitable other proteins may be naturally occurring or recombinant. They may act as “wall-forming materials”, as described in WO92/18164, where various examples are given. A preferred material is HSA (human serum albumin). For example, fibrinogen is spray-dried alone or in the presence of varying amounts of excipients such as HSA (e.g. fibrinogen: HSA ratios of 1:1, 1:3, 3:1) and trehalose. Other suitable substitutes for HSA include surfactants, such as Tween 20, Tween 80, Poloxamer 407 or Poloxamer 188.
Calcium ion, e.g. as calcium chloride, may be incorporated in the thrombin feedstock. Alternatively, calcium chloride may be added to the microcapsules after processing.
Microparticles of the invention may be sterilised, if necessary or desired. Sterile processing, electron beam irradiation, y-irradiation and ethylene oxide are examples of suitable techniques.
Although the components of the microcapsules in a fibrin sealant of the invention are preferably water-soluble, and the microparticles are preferably obtained by spray-drying a suitable solution, the microparticles that are obtainable may be free-flowing, discrete and substantially anhydrous, with a residual moisture content preferably no greater than 5% w/w, most preferably no greater than 3% w/w. This means that the compounds of fibrin sealant in accordance with this invention are not activated until they are wetted, e.g. by coming into contact with liquid at a wound site. The active components may therefore be delivered as a dry mixture, although separate application of the different microparticles is also envisaged.
A dry powder fibrin sealant product may be of particular value where application to a large surface area is required. This includes surgery and repair of traumatic injuries to various organs such as the liver and spleen. A further advantageous application is in skin grafting for burns patients, and specifically where skin epidermal sheets are cultured in vitro and then transferred to the wound site. The use of fibrin sealant in the latter indication may be particularly effective in patients with extensive burns, providing a biocompatible anchorage for skin grafts. It may also be suitable in the treatment of topical ulcers.
The following Examples illustrate the invention.
EXAMPLE 1
Spray-dried fibrinogen microparticles were prepared by dissolving 73.8 g human fibrinogen in 1650 mL water containing 275.1 g trehalose dihydrate. The resultant solution was spray-dried on a Niro Mobile Minor spray dryer using the following operating parameters:
Inlet temperature:
160° C.
Atomisation type:
2 - Fluid Nozzle
Liquid insert:
0.5 mm
Atomisation pressure:
0.5 bar
Feed rate:
18 g/minute
The spray-dried powder had a particle size (X50, geometric diameter) of 18.4 μm and a fibrinogen content of 152 mg/g. The moisture content (Karl-Fischer) was 2%.
Spray-dried thrombin microparticles were prepared by dissolving 751,230 IU human thrombin in 1653 mL water containing 11.5 g calcium chloride dihydrate and 507.3 g trehalose dihydrate. The resultant solution was spray-dried on a Niro Mobile Minor spray dryer using the following operating parameters:
Inlet temperature:
160° C.
Atomisation type:
2 - Fluid Nozzle
Liquid insert:
0.5 mm
Atomisation pressure:
0.5 bar
Feed rate:
18 g/minute
The spray-dried powder had a particle size (X50, geometric diameter) of 12.5 μm and a thrombin content of 977 IU/g. The moisture content (Karl-Fischer) was 3%.
The two spray-dried powders were blended in a 1:1% w/w ratio using a drum mixer at 18 rpm for 15 minutes. The resultant blend had a particle size of 15.5 μm, and a fibrinogen content of 69.1 mg/g.
The respective particle size distributions are shown in FIGS. 1 and 2 .
FIG. 1 shows the cumulative distribution as follows:
x 0 /μm
Q 3 /%
1.80
6.71
2.20
8.45
2.60
10.02
3.00
11.48
3.60
13.58
4.40
16.36
5.20
19.25
6.20
23.15
7.40
28.33
8.60
33.97
10.00
40.87
12.00
50.65
15.00
64.07
18.00
75.17
21.00
83.61
25.00
91.27
30.00
96.53
36.00
99.11
42.00
99.85
50.00
100.00
60.00
100.00
72.00
100.00
86.00
100.00
102.00
100.00
122.00
100.00
146.00
100.00
174.00
100.00
206.00
100.00
246.00
100.00
294.00
100.00
350.00
100.00
Evaluation:
WINDOX 5.1.2.0, HRLD
Product: Fibrocaps
Revalidation:
Density: 1.00 g/cm 3 , shape factor: 1.00
Reference measurement:
Disp. Meth: Set up for Fibrocaps R/M
08-20 11:42:05
C opt = 1.56%
Contamination: 0.00%
Trigger condition: Fibrocaps User parameters: Time base: 200.00 ms Batch Number: PV Thrombin Start: c.opt >= 0.2% Formulation: EM/08/126 Valid: always Name: aks Stop: 2.000 s c.opt <= 0.2% or Run Number: Run 1 10000 s real time FIG. 2 shows the cumulative distribution as follows:
x 0 /μm
Q 3 /%
1.80
2.68
2.20
3.58
2.60
4.53
3.00
5.52
3.60
7.06
4.40
9.19
5.20
11.39
6.20
14.20
7.40
17.63
8.60
21.10
10.00
25.15
12.00
30.88
15.00
39.17
18.00
46.85
21.00
53.70
25.00
61.53
30.00
69.48
36.00
76.91
42.00
82.47
50.00
87.80
60.00
92.11
72.00
95.07
86.00
96.87
102.00
97.94
122.00
98.72
146.00
99.34
174.00
99.81
206.00
100.00
246.00
100.00
294.00
100.00
350.00
100.00
Evaluation:
WINDOX 5.1.2.0, HRLD
Product: Fibrocaps
Revalidation:
Density: 1.00 g/cm 3 , shape factor: 1.00
Reference measurement:
Disp. Meth: Set up for Fibrocaps R/M
08-29 13:35:41
C opt = 7.30%
Contamination: 0.00%
Trigger condition: Fibrocaps
User parameters:
Time base: 200.00 ms
P1: SD Fibrinogen: trehalose clinical
Start: c.opt >= 0.2%
P2: EM/08/129
Valid: always
P3: TR
Stop: 2.000 s c.opt <= 0.2% or
P4: run 1
10000 s real time
EXAMPLE 2
Four batches of microparticles were produced, using the following formulations and a Mini spray dryer,
200 mg/ml trehalose-200 units/ml thrombin 200 mg/ml sucrose-200 units/ml thrombin-1% HSA w-v 200 mg/ml trehalose-40 mg/fibrinogen 200 mg/ml sucrose-40 mg/ml fibrinogen.
The spray-drying parameters were selected so as to produce particles in the region of 10 μm.
Thrombin Formulation:
Inlet temperature 130° C. Outlet temperature ~80° C. Atomisation airflow 5 liter-min Drying airflow: 5 liter-sec Feed Rate: 5.0 g-min
Fibrinogen Formulation:
Inlet temperature:
130° C.
Outlet temperature:
~83° C.
Atomisation Airflow:
15 liter-sec
Drying airflow:
5 liter-sec
Feed Rate:
3.0 g-min
Each of the microcapsules batches was aliquoted into clear 10 ml glass vials both as separate components and as excipient-matched blends. A stability study at 4° C. was conducted over four weeks. Four timepoints were selected; initial, 1 week, 2 weeks and 4 weeks, and the following assays were employed to compare the effect of the different excipients on the stability and bioactivity retention.
Fibrinogen Analysis used a polyconal antibody to human fibrinogen as a capture antibody and a second peroxidise-labelled antibody to human fibrinogen is used for detection in a chromogenic assay.
Thrombin Analysis was based on a commercial substrate which is sensitive to thrombin and gives a colour change which can be measured. The initial rate of change in absorbance is proportional to thrombin concentration.
Particle Size was measured using a LS230 Laser Sizer in conjunction with Medium Chain Trigylceride oil to determine the particle size of the spray dried material.
Thermogravimetric Analysis was carried out to assess moisture content.
Flow time was the time taken for a microcapsule blend to pass through a funnel of a pre-determined size was used as a comparative measure of flowability between batches.
Angle of Repose indicates the flowability of a powder and was measured by the calculation of the angle created upon the flow of a powder through a funnel and subsequent accumulation on a flat surface.
Packed and tap density were measured using the Jolting Volume Meter and the values used in Carrs Compressibility Index (% CCI).
Clot Strength utilises the formulation of a clot from a blend in a plastic syringe. A bead is suspended in the syringe prior to clot formation and the weight required to pull the bead through the clot is recorded.
Adhesive Strength: blends are applied to a piece of rat skin via a 10 ml glass pipette fitted with a compressed air supply. The weight required to separate two pieces of the tissue bonded together by a blend is used as a measurement of adhesive strength. (This assay is based on a Gottlob skin test method—Gesting and Lerner: Autologous fibrinogen for tissue adhesion haemostatis (1983)).
Additional assays were performed at the four week timepoint; SDS PAGE to assess the effects of spray-drying on the structural integrity of the bioactives and a BCA assay for total protein determination. Scanning electron micrographs (SEM) were also obtained for each of the individual formulations.
Results demonstrated no significant changes over the stability period for either formulation, but the data do suggest a greater retention of activity generated for the trehalose formulation when compared with the sucrose formulation. The clot strength values also indicate an increased activity retention with the trehalose formulation. The addition of HSA to the trehalose-thrombin formulation showed no significant differences in bioactivity retention compared to the trehalose-thrombin formulation. The flow properties were retained over the stability period which is reflected in the consistent adhesive strength values.
SDS PAGE data demonstrated the retention of structural integrity post-spray-drying.
Scanning electron micrographs revealed similar morphology for all formulations.
Dry heat viral inactivation step was conducted for 72 hours at 80° C.
The individual fibrinogen and thrombin components were assessed using ELISA and chromogenic assays respectively and the blends were analysed using the clot strength assay. The results are documented in Table 1.
TABLE 1
Dry Heat Sterilisation
Bioactivity -
Clot
Concentration per 100 mg
Strength
Sample
spray-dried Product
(g)
Trehalose - Thrombin
101.6 units (97%)
*
microcapsules
Trehalose - Fibrinogen
14.17 mg (103%)
*
microcapsules
Trehalose - Active blend
*
64.8 g
Sucrose - Thrombin
93.8 units (89%)
*
microcapsules
Sucrose - Fibrinogen
11.04 mg (80.5)
*
microcapsules
Sucrose - Active blend
*
62.7 g
Theoretical thrombin concentration=105 units-100 mg spray-dried product
Theoretical fibrinogen concentration=13.7 mg-100 mg spray-dried product
% Retention is shown in brackets
Expected clot strength=˜70 g
The bioanalytical results indicate the excipient trehalose allows a greater retention of the active during the dry heat step.
Gamma-irradiation employed 25 kGy at a rate of 8 kGy/hour. Samples were exposed to these irradiation conditions both as separate components and as a blend.
The components were assessed using ELISA and chromogenic assays respectively and the blends examined via the clot strength assay. The results are documented in Table 2.
TABLE 2 Gamma Irradiation Sterilisation Bioactivity - Clot Concentration per 100 mg Strength Sample spray-dried Product (g) Trehalose - Thrombin 71 units (71%) * microcapsules Trehalose - Fibrinogen 10.3 mg (73%) * microcapsules Trehalose - Active blend * 59.5 g Sucrose - Thrombin 71 units (71%) microcapsules Sucrose - Fibrinogen 7.7 mg (55.5 %) * microcapsules Sucrose - Active blend * 36.9 g
% Retention is shown in brackets.
The conditions investigated in the terminal sterilisation study (72 hours at 80° C.) suggest that trehalose offers a higher level of protection to the protein, as reflected by the activity retention. This observation may also suggest a trehalose formulation may be capable of room temperature storage. Gamma irradiation of the sucrose formulation resulted in a 50% drop in fibrinogen activity. The trehalose formulation was found to have a significantly higher fibrinogen activity retention (70%) as measured by the ELISA and clot strength assays.
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The invention provides a composition comprising a mixture of first microparticles that comprise fibrinogen and trehalose, and second microparticles that comprise thrombin and trehalose. The invention further provides methods for treating wounds by administering the novel microparticle composition.
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FIELD OF THE INVENTION
[0001] This invention relates generally to an endocardial lead cutting apparatus and, more particularly, to an apparatus including at least one blade or cutting surface for cutting endocardial leads within a patient.
BACKGROUND OF THE INVENTION
[0002] In the past, various types of endocardial leads and electrodes have been introduced into different chambers of a patient's heart, including the right ventrical, right atrial appendage, and atrium as well as the coronary sinus. These flexible leads usually are composed of an insulator sleeve that contains an implanted helical coil conductor that is attached to an electrode tip. This electrode is placed in contact with myocardial tissue by passage through a venous access, often the subclavian vein or one of its tributories, which leads to the endocardial surface of the heart chambers. The tip with the electrode contact is held in place by trabeculations of myocardial tissue.
[0003] The tips of many available leads include flexible tines, wedges, or finger-like projections which extend radially outward and usually are molded from and integral with the insulating sheath of the lead. These tines or protrusions allow surrounding growth of tissue in chronically implanted leads to fix the electrode tip in position in the heart and prevent dislodgement of the tip during the life of the lead. In “acute placement” of the electrode or lead tip, a blood clot forms about the flanges or tines (due to enzymes released as a result of irritation of the trabeculations of myocardial tissue by the presence of the electrode tip) until scar tissue eventually forms, usually in three to six months. The tines or wedges or finger-like projections allow better containment by the myocardial trabeculations of muscle tissue and prevent early dislodgement of the lead tip.
[0004] Although the state of the art in implemented pulse generator or pacemaker technology and endocardial lead technology has advanced considerably, endocardial leads nevertheless occasionally fail, due to a variety of reasons, including breakage of a lead, insulation breaks, breakage of the inner helical coil conductor and an increase in electrode resistance. Furthermore, in some instances, it may be desirable to electronically stimulate different portions of the heart than are presently being stimulated with the leads already implanted. There are a considerable number of patients who have one or more, and sometimes as many as four or five unused leads in their veins and heart.
[0005] Although it obviously would be desirable to easily remove such unused leads, in the past surgeons usually have avoided attempts to remove inoperative leads because the risk of removing them exceeded the risk of leaving them in. The risks of leaving unused myocardial leads in the heart and venous path include increased likelihood that an old lead may facilitate infection, which in turn may necessitate removal of the lead to prevent continued bacteremia and abcess formation. Furthermore, there is an increased likelihood of the formation of blood clots in the atrial chamber about entangled leads. Such clots may embolize to the lung and produce severe complications and even fatality. Furthermore, the presence of unused leads in the venous pathway and inside the heart can cause considerable difficulty in the positioning and attachment of new endocardial leads in the heart.
[0006] Removal of an inoperative lead sometimes can be accomplished by applying traction and rotation to the outer free end of the lead, for example, if done prior to fixation of the lead tip in the trabeculations of myocardial tissue by scar tissue formation or large clot development. Even then, it is possible that a clot has formed so the removal of the leads causes various sized emboli to pass to the lungs, producing severe complications.
[0007] In cases where the lead tip has become attached by scar tissue to the myocardial wall, removal of the lead always has presented major problems and risks. Porous lead tips that are sometimes used may have an ingrowth of scar tissue attaching them to the myocardial wall. Sufficient traction on such leads in a removal attempt could cause disruption of the myocardial wall prior to release of the embedded lead tip. The tines or flanges of other types of leads that are not tightly scarred to the myocardial wall present similar risks. Even if screw-in tip electrodes are used, wherein the tips theoretically can be unscrewed from the myocardial wall, unscrewing of such tips may be prevented by a channel of scar tissue and endothelium that surrounds the outer surface of the lead along the venous pathway. Such “channel scar” tissue prevents withdrawal because of tight encasement of the lead. Continual strong pulling or twisting of the outer free end of the lead could cause rupture of the atrial wall or the ventricular wall if there is such tight circumferential encasement of adherent channel scar tissue in the venous path. Such tight encasement by scar tissue in the venous pathway and in the trabeculations of the myocardial wall typically occurs within six months to a year of the initial placement of the lead.
[0008] The risks of removing the lead by such traction and rotation of the lead are so high that, if it becomes imperative that the lead be removed (as in the case of infection), most surgeons have elected to open the patient's chest and surgically remove the lead rather than attempt removal by applying traction and rotation thereto.
[0009] Clearly, there is a need for an apparatus for extracting endocardial leads from a patient's heart with minimal risk to the patient.
SUMMARY OF THE INVENTION
[0010] To address these and other drawbacks, in some embodiments, without limitation, the present invention comprises an apparatus for cutting the lead as near as possible to an endocardial lead's embedded electrode.
[0011] Specifically, the present invention comprises an apparatus having a generally flexible tubular member having a proximal end and distal end. At least one blade or cutting surface is affixed to the distal end of the tubular member. In some embodiments, the apparatus includes an adjustment mechanism adapted to adjust the blade or cutting surface between an extended position and a retracted position.
[0012] Other aspects of the invention will be apparent to those skilled in the art after reviewing the drawings and the detailed description below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0014] FIG. 1 illustrates a perspective view of an endocardial lead cutting apparatus of a first embodiment of the present invention;
[0015] FIG. 2 illustrates a perspective view of an endocardial lead cutting apparatus of a second embodiment of the present invention;
[0016] FIG. 3 illustrates an enlarged perspective view of a distal end of an outer tubular member of the second embodiment of the present invention;
[0017] FIG. 4 illustrates an enlarged perspective view of a distal end of an inner shaft of the second embodiment of the present invention;
[0018] FIG. 5A-5C illustrate end views of the endocardial lead cutting apparatus of the second embodiment of the present invention having the inner shaft rotating to cut the lead;
[0019] FIG. 6 illustrates a cross-sectional view of an endocardial lead cutting apparatus of a third embodiment of the present invention;
[0020] FIG. 7 illustrates an enlarged cross-sectional view of a distal end of the endocardial lead cutting apparatus of the third embodiment of the present invention;
[0021] FIG. 8 illustrates a perspective view of an endocardial lead cutting apparatus of a fourth embodiment of the present invention;
[0022] FIG. 9 illustrates a perspective view of an endocardial lead cutting apparatus of a fifth embodiment of the present invention;
[0023] FIG. 10 illustrates a perspective view of an endocardial lead cutting apparatus of a sixth embodiment of the present invention; and
[0024] FIGS. 11A-11C illustrate enlarged perspective views of the distal end of the endocardial lead cutting apparatus of the sixth embodiment.
DETAILED DESCRIPTION
[0025] Referring generally to FIGS. 1-11 and without limiting the scope of the embodiments of the invention, various embodiments of an apparatus are generally referred to at 10 for cutting an endocardial lead 100 .
[0026] Referring to FIG. 1 , the apparatus 10 of a first embodiment includes a shaft 12 having a proximal end 14 and a distal tip 16 . The shaft 12 is generally flexible to facilitate movement of the apparatus 10 within the patient. The proximal end 14 of the shaft 12 includes a handle 18 while the distal tip 16 includes at least one cutting surface 20 .
[0027] The at least one cutting surface 20 is defined by a groove 22 at the distal tip 16 . The groove 22 is illustrated as generally v-shaped. Accordingly, as illustrated, the v-shaped groove 22 defines two cutting surfaces 20 . Further, the cutting surfaces 20 are comprised of a generally hardened material, such as carbide and the like. While illustrated as a v-shaped groove 22 , other configurations, such as u-shaped, c-shaped and the like are contemplated by the present invention.
[0028] Optionally, a shroud (not shown) is positioned about the shaft 12 such that a distal end of the shroud extends outwardly of the distal tip 16 of the shaft 12 . The shroud is made of a generally pliable material to prevent damage to tissue of the patient prior to use of the apparatus 10 .
[0029] Further, as an additional optional feature, the apparatus 10 may include a device (not shown) to provide an additional form of energy to cut the endocardial lead. By way of example, the device may be a laser generating device, an ultrasonic device, a vibration device and the like. The exemplary devices would apply radiation, ultrasonic waves or vibrations, respectively, to the lead 100 to assist in cutting the lead 100 . In the example of a laser generating device, an optical fiber (not shown) would be disposed within the shaft 12 to transmit radiation from the proximal end 14 to the distal tip 16 .
[0030] In operation, the first embodiment of apparatus 10 of FIG. 1 is inserted within a patient's heart (not shown) and the lead 100 (shown in phantom) is received within the groove 22 at the distal tip 16 . When positioned to receive the lead 100 the pliable shroud is urged away from the distal tip 16 to expose the groove 22 and cutting surfaces 20 . Linear and rotation motion is applied by way of the handle 18 to the shaft 12 . The cutting surfaces 20 of the groove 22 then engages the lead. As additional pressure is applied the cutting surfaces 20 cut the lead and the apparatus 10 is removed from the patient. Optionally, when the lead 100 is received in the groove 22 the additional forms of energy such as radiation, ultrasound or vibration is applied to the lead to assist in cutting the lead 100 .
[0031] A second embodiment of the apparatus 10 is shown in FIGS. 2-5 . The second embodiment includes an outer tubular member 212 having a proximal end 214 and a distal end 216 . The outer tubular member 212 is generally flexible to facilitate movement of the apparatus 10 within the patient. The distal end 216 includes a groove 220 for receiving the lead 100 . As illustrated, the groove 220 is generally v-shaped for receiving the lead 100 ; however, other configurations are also contemplated by the present invention.
[0032] An inner shaft 222 is received within the outer tubular member 212 . The inner shaft 222 includes a proximal end 224 and a distal end 226 . Further, the inner shaft 222 is generally flexible and includes a handle 228 disposed at the proximal end 224 . Positioned at the distal end 226 of the inner shaft is a blade 230 . The blade 230 and the inner shaft 222 is made from a generally hardened material, such as carbide and the like, and rotates within the outer tubular member 212 to cut the lead 100 received within the groove 220 of the outer tubular member 212 . The inner shaft 222 and blade 230 are rotatable in either direction.
[0033] Further, as described with respect to the first embodiment of FIG. 1 , the apparatus 10 may include a shroud (not shown). The shroud is positioned about the outer tubular member 212 such that a distal end of the shroud extends outwardly of the distal end 216 of the outer tubular member 212 . The shroud is made of a generally pliable material to prevent damage to tissue of the patient prior to use of the apparatus 10 .
[0034] In operation, the second embodiment of apparatus 10 of FIGS. 2-5 is inserted within a patient's heart and the lead 100 is received within the groove 220 at the distal end 216 of the outer tubular member 212 . When receiving the lead 100 within the groove 220 , the inner shaft 222 and blade 230 are in a home position such that the blade 230 is generally offset from the groove 220 . A positioning mechanism (not shown) may be included to bias the inner shaft 222 and blade 230 to the home position within the outer tubular member 212 . When positioned to receive the lead 100 the pliable shroud is urged away from the distal end 216 to expose the groove 220 and blade 230 . When the distal end 216 of the outer tubular member 212 is positioned as close as possible to the embedded electrode of the lead, the handle 228 of the inner shaft 222 is rotated and the blade 230 contacts the lead. Further rotation of the inner shaft 222 and the blade 230 cuts the lead 100 . The apparatus 10 is then removed from the patient.
[0035] Now referring to FIGS. 6-7 , a third embodiment of the apparatus 10 of the present invention is illustrated. The apparatus 10 includes a tubular member 312 having a proximal end 314 and a distal end 316 . The tubular member 312 is generally flexible and preferably made from a plastic or elastomeric material.
[0036] A housing 318 is generally disposed at the distal end 316 of the tubular member 312 . The housing 318 includes an opening 320 for receiving the endocardial lead 100 . Preferably, the housing 318 is made of stainless steel and is joined to the distal end 316 of the tubular member 312 by use of an adhesive. However, any technique for joining the housing 318 and the distal end 316 of the tubular member 312 is contemplated by the present invention.
[0037] Disposed within the housing 318 are a blade 322 and a plunger 324 . The blade 322 is received within the plunger 324 , preferably by press-fitting the blade 322 within the plunger 324 . The blade 322 is made of carbide and moveable between an extended position and a retracted position. When in the extended position, the blade 322 is received within the opening 320 of the housing 318 to cut the lead 100 received therein.
[0038] The tubular member 312 includes a handle 326 . The handle 326 is joined to the proximal end 314 of the tubular member 312 by adhesive and the like. Alternately, the handle 326 is press fit within the proximal end 314 of the tubular member 312 . The handle 326 is utilized to actuate the blade 322 between the extended and retracted positions.
[0039] Further, the apparatus 10 of the third embodiment includes an adjustment mechanism generally referred to at 328 . The adjustment mechanism 328 moves the blade 322 between the extended and retracted positions. Specifically, the adjustment mechanism 328 may comprise a screw 330 . A first end 332 of the screw 330 is received at a proximal end 334 of the plunger 324 . A second end 336 of the screw 330 extends through a retainer 338 . The retainer 338 is generally disposed at a proximal end 340 of the housing 318 .
[0040] The adjustment mechanism 328 further includes a universal joint 342 and drive wire 344 . The universal joint 342 is disposed at the second end 336 of the screw 330 . The universal joint 342 is also attached to the drive wire 344 . The drive wire 344 extends through the tubular member 312 and attaches to the handle 326 . Further, the handle 326 includes a knob 346 . The knob 346 rotates to adjust the blade 322 between the extended and retracted positions.
[0041] In operation, the apparatus 10 of the third embodiment of the present invention of FIGS. 6-7 is inserted within a patient's heart and receives the lead 100 within the opening 320 of the housing 318 . The adjustment mechanism 328 is actuated by rotating the knob 346 . Rotational motion from the knob 346 is transferred through the drive wire 344 and universal joint 342 to rotate the screw 330 . Rotation of the screw 330 advances the screw through the retainer 338 to move the plunger 324 and blade 322 from the retracted position to the extended position. Accordingly, the blade 322 is received in the opening 320 of the housing 318 and contacts the endocardial lead 100 . The lead 100 is then cut by further extension of the blade 322 and the apparatus 10 is removed from within the patient.
[0042] Referring to FIG. 8 , the fourth embodiment of the apparatus 10 of the present invention is illustrated. The apparatus 10 includes a tubular member 412 having a proximal end 414 and a distal end 416 . The distal end 416 is generally u-shaped to define a first cutting surface 418 . At the proximal end 414 of the tubular member 412 is a handle 420 . The tubular member 412 may be generally flexible to move within the patient.
[0043] Disposed within the tubular member 412 is a tension member 422 . The tension member 422 includes a proximal end 424 and a distal end 426 . The proximal end 424 of the tension member 422 is fixed to a lever 428 . The distal end 426 of the tension member 422 is fixed to a blade 430 . The blade 430 is pivotally connected to the distal end 416 of the tubular member 412 and actuation of the lever 428 about the handle 420 pivots the blade 430 to capture the lead 100 between the blade and the first cutting surface 418 .
[0044] Further, blade 430 has a generally s-shaped configuration and defines a first end 432 , a second end 434 and a connecting leg 436 extending therebetween. The first end 432 includes an inner surface that defines a second cutting surface 438 . The second end 434 is fixed to the proximal end 424 of the tension member 422 . The connecting leg 436 of the blade 430 is pivotally connected to the distal end 416 of the tubular member 412 . As illustrated the blade 430 is connected to the distal end 416 of the tubular member 412 generally at the midpoint of the connecting leg 436 . However, alternative fastening positions or techniques are easily contemplated by one skilled in the art.
[0045] In operation, the apparatus 10 of the fourth embodiment is placed within a patient and the lead 100 is received within the u-shaped distal end 416 of the tubular member 412 such that the first cutting surface 418 contacts the lead 100 . The lever 428 is actuated about the handle 420 to draw the tension member 422 away from the distal end 416 and pivot the blade 430 thereabout. When the blade 430 is pivoted, the second cutting surface 438 of the first end 432 also contacts the lead 100 to capture the lead 100 therebetween. Further actuation of the lever 428 and the cutting surfaces 418 , 438 cut through the endocardial lead 100 .
[0046] Referring to a fifth embodiment of FIG. 9 , the apparatus 10 includes a tubular member 512 having a proximal end 514 and a distal end 516 . The distal end 516 is generally c-shaped to define a first cutting surface 518 . At the proximal end 514 of the tubular member 512 is a handle 520 . The tubular member 512 may be generally flexible to move within the patient.
[0047] Disposed within the tubular member 512 is a tension member 522 . The tension member 522 includes a proximal end 524 and a distal end 526 . The proximal end 524 of the tension member 522 is fixed to a lever 528 . The distal end 526 of the tension member 522 is fixed to a blade 530 . The blade 530 is received within the tubular member 512 and disposed at the distal end 516 . Actuation of the lever 528 about the handle 520 linearly moves the blade 530 to capture the lead 100 between the blade 530 and the first cutting surface 518 . The blade 530 defines a second cutting surface 532 and capturing the lead 100 between the blade 530 and the first cutting surface 518 cuts the lead 100 .
[0048] In operation, the apparatus 10 of the fifth embodiment is placed within a patient and the lead 100 is received within the c-shaped distal end 516 of the tubular member 512 such that the first cutting surface 518 contacts the lead 100 . The lever 528 is actuated about the handle 520 to draw the tension member 522 away from the distal end 516 and move the blade 530 linearly. When the blade 530 is moved, the second cutting surface 532 of the blade 530 also contacts the lead 100 to capture the lead 100 between the blade 530 and the first cutting surface 518 . Further actuation of the lever 528 and the cutting surfaces 518 , 532 cut through the endocardial lead 100 .
[0049] Now referring to FIGS. 10-11 , the sixth embodiment of apparatus 10 of the present invention is illustrated. The apparatus 10 includes a tubular member 612 having a proximal end 614 and a distal end 616 . The distal end 616 includes a housing 618 while the proximal end 614 includes an adjustment mechanism 620 . The tubular member 612 may be generally flexible to move within the patient and optionally include reinforcements such as a braid or compressed coil to strengthen the tubular member 612 and resist compression during operation.
[0050] Disposed within the tubular member 612 is a tension member 622 . The tension member 622 includes a proximal end 624 and a distal end 626 . The proximal end 624 of the tension member 622 is fixed to the adjustment mechanism 620 while the distal end 626 is connected to two blades 628 . The adjustment mechanism 620 moves the tension member 622 and the blades 628 between an extended position and a retracted position.
[0051] The adjustment mechanism 620 includes a handle 630 for actuating the tension member 622 and blades 628 between the extended and retracted positions. Pivotally connected to the handle 630 is a lever 632 with a biasing mechanism 634 , such as a spring and the like, disposed therebetween. The biasing mechanism 634 urges the lever 632 about the handle 630 and hence, the tension member 622 and blades 628 to one of either the extended or retracted positions. Optionally, the adjustment mechanism 620 may also include a knob 636 for actuating the tension member 622 and blades 628 to a position opposite of the bias of the handle 630 and lever 632 configuration. Further, various alternatives for actuating the tension member 622 and blades 628 between positions are contemplated by the present invention, especially techniques previously described in the present application.
[0052] Referring to FIGS. 11A-11C , the blades 628 of the present embodiment are pivotally connected and may generally be described as have a scissor cutting action. The blades 628 are made of a generally hardened material such as hardened steel, carbide and the like. The blades 628 are general arcuate to define an inner cutting surface 638 . Each blade 628 includes a first end 640 and a second end 642 . The first ends 640 of the blades 628 are generally rounded or blunt-tipped to minimize damage to surrounding tissue when within a patient. The second ends 642 of the blades 628 are connected to the distal end 626 of the tension member 622 .
[0053] The blades 628 are received within the housing 618 disposed at the distal end 616 of the tubular member 612 . The housing 618 is preferably made from plastic and includes tapered sides 644 . The tapered sides 644 urge the blades 628 to pivot about each other when moved from the extended position to the retracted position within the housing 618 .
[0054] Optionally, the apparatus 10 of the sixth embodiment may also include a capture mechanism (not shown). The capture mechanism is disposed within the tubular member 612 . The capture mechanism is preferably a wire, more preferably a deflectable guide or snare wire, made of a flexible or bendable material and having a biased arcuate distal end (also not shown). The capture mechanism is moveable between an extended position and a retracted position similar to the tension member 622 and the blades 628 . When extended, the biased arcuate distal end wraps around the endocardial lead 100 , by way of example only, by snaring the lead, to draw the lead 100 close to the distal end 616 and housing 618 of the tubular member 612 . When retracted, the biased arcuate distal end is generally longitudinal and received within the housing 618 and tubular member 612 .
[0055] In operation, the apparatus 10 of the sixth embodiment is placed within a patient. The capture mechanism is extended and the biased arcuate distal end wraps about the endocardial lead 100 . The capture mechanism is retracted to draw the lead 100 close to the distal end 616 and housing 618 of the tubular member 612 . The tension member 622 and blades 628 are extended as shown in FIG. 11A . The adjustment mechanism 620 is actuated and the tension member 622 and blades 628 are moved to the retracted position. As seen in FIG. 11B , the blades 628 pivot about each other at the second end 642 to capture the lead 100 between the inner cutting surfaces 638 of the blades 628 . Further actuation and retraction of the tension member 622 and blades 628 cuts through the lead 100 as shown in FIG. 11C . The apparatus 10 is then removed from within the patient.
[0056] While the present invention has been particularly shown and described with reference to the foregoing preferred and alternative embodiments, it should be understood by those skilled in the art that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention without departing from the spirit and scope of the invention as defined in the following claims. It is intended that the following claims define the scope of the invention and that the apparatus within the scope of these claims and their equivalents be covered thereby. This description of the invention should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be present in this or a later application to any novel and non-obvious combination of these elements. The foregoing embodiments are illustrative, and no single feature or element is essential to all possible combination that may be claimed in this or a later application. Where the claims recite “a” or “a first” element of the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.
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In some embodiments, without limitation, the invention comprises an apparatus for cutting an endocardial lead within a patient. The apparatus comprises a generally flexible tubular member having a proximal end and distal end. At least one blade or cutting surface is affixed to the distal end of the tubular member. The apparatus optionally includes an adjustment mechanism adapted to adjust the blade or cutting surface between an extended position and a retracted position. The blade or cutting surface engages the endocardial lead to cut the lead. Various embodiments include a v-shaped groove defining the cutting surfaces. Other embodiments may comprise a rotatable blade of an inner shaft rotating within the tubular member and cutting the lead received within the v-shaped groove, and blades or cutting surfaces functioning like guillotines or scissors retracting into a distal end of the tubular member.
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RELATED PATENT APPLICATIONS
[0001] This application claims priority to U.S. provisional patent application Ser. No. 60/691,144 filed 16 Jun. 2005, entitled “Harmonic Linear Actuator and Flexing Splined Interlock for Harmonic Motor or Linear Actuator”. This application is also related to U.S. application Ser. No. 11/412,057 filed 26 Apr. 2006, entitled “Harmonic Drive Linear Actuator”, the specification of which is expressly incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates generally to motors, and more particularly to motors employing harmonic drives.
BACKGROUND OF THE INVENTION
[0003] Motors include harmonic motors. One type of harmonic motor has a rotatable rotor and a surrounding nonrotatable stator. The rotor makes a single point of contact with the inner circumference of the stator. The single point of contact rotates around (i.e. rolls around) the inner circumference of the stator. The rotor rotates a few degrees about its longitudinal axis for each complete rotation of the single point of contact about the inner circumference of the stator. In one modification, the outer circumference of the rotor and the inner circumference of the stator have gear teeth. Such motors find use in high torque, low speed motor applications. In one known variation, the rotatable rotor is above a nonrotatable stator, and the rotatable rotor flexes or wobbles downward to make a single point of contact with the stator, the single point of contact rotates around an “inner circumference” of the stator, and the rotor rotates a few degrees about its longitudinal axis for each complete rotation of the single point of contact. In another type of harmonic motor, a shaft is surrounded by a shaft-driving member, which is brought into a single point of contact with the shaft by electro-restrictive devices, wherein the rotor rotates a few degrees for each complete rotation of the single point of contact around an inner circumference of the shaft-driving member.
[0004] Harmonic motors are generally used to impart rotary motion, and may be of the type described in, for example, U.S. Pat. No. 6,664,711 B2 entitled “Harmonic Motor”, the disclosure of which is expressly incorporated herein by reference. Such motors employ a first, flexible annular member provided with gear teeth that are engagable with gear teeth of a second member surrounding or surrounded by the first annular member, the first annular member actually being cup-shaped as described herein below, and also referred to as a flex-tube.
[0005] Harmonic drive gear trains are known. In one known design, a motor rotates a “wave generator” which is an egg-shaped member, which flexes diametrically opposite portions of the surrounding flex-spline gear, which is inside an outer gear. As the diametrically opposite teeth of the flex-spline gear contact the teeth on the outer gear, the rotatable one of the gears rotates with respect to the nonrotating one of the gears.
[0006] Currently, the only method of preventing rotation of the annular flexible member in a harmonic motor or actuator is to configure the member to have a generally cylindrical body with opposite open and closed ends, where the rim and a base are respectively located. That is, existing flex-tubes in such devices are cup-shaped rather than truly tubular. This cup configuration allows the wall at and near the rim of the first, annular flex tube member to be moved into operative engagement with the second annular member and still be fixed at its base against rotation.
[0007] However, to bring the rim of the flex-tube and the second member into operative engagement requires additional work and power to bend the cup-shaped flex-tube's base and flex its cylindrical wall near the base.
[0008] What is needed is a new type of harmonic motor or actuator device having a flexible member which does not rotate, requires less power to operate, and simultaneously reduces the effective gear ratio between the rotor and stator.
SUMMARY OF THE INVENTION
[0009] The present invention provides a harmonic drive device such as a harmonic motor or harmonic actuator having a flex-tube that is tubular rather than cup-shaped, and yet is prevented from rotating during operation of the device. The first tubular, flexible member of the inventive device is provided with inner and outer generally cylindrical surfaces, one of which is provided with gears or threads that respectively inter-engage with gears or threads on the second member to induce linear or rotational movement or the second member, as the case may be. The other of the first member's inner and outer generally cylindrical surfaces is provided with gear teeth or splines that are engaged with identical mating gear teeth or splines on a stationary third member or armature in a circumferentially moving manner. The inter-engagement of the armature, flexible first member and movable second member prevent rotation of the first member during operation of the harmonic motor or harmonic actuator.
[0010] In the preferred embodiment of the invention, a harmonic motor includes a first annular member, second and third members, and a device for flexing the first annular member. The first annular member has a longitudinal axis, lies on a plane perpendicular to the longitudinal axis, and is flexible in a direction, which lies in the plane. The second and third members are substantially coaxially aligned with the first annular member and lay in the plane. One of the second and third members is rotatable about the longitudinal axis, and the other or the first and second members is non-rotatable about the longitudinal axis. The flexing device flexes the first annular member to rotate the at least two spaced-apart points of contact with the second member and an additional at least two spaced-apart points of contact with the third member, and sequentially flexes the first annular member to rotate the points of contact with said second and third members about the longitudinal axis which rotates the rotatable one of said second and third members about the longitudinal axis.
[0011] Several benefits and advantages are derived from the preferred embodiment of the invention. By using at least two points of contact between the first annular and second members as well as the first annular and third members, the rotatable one (i.e. the rotor) of the second and third members is being driven by at least two points of contact by the non-rotatable one (i.e. the rotor driving member or stator) of the second and third members. Driving the motor with at least two points of contact provides a more robust and more smoothly operating motor than is provided in the prior art, as can be appreciated by the artisan. In addition, mechanical interconnection torque input/output interconnection means directly to the flexible member is avoided.
[0012] In another aspect of the preferred embodiment, the first annular member assumes a substantially cylindrical configuration due to its inherent resiliency when the flexing means is not active. This results in mechanical disengagement between the second and third members, preventing any undesirable load back-drive.
[0013] These and other features and advantages of this invention will become apparent upon reading the following specification, which, along with the drawings, describes preferred and alternative embodiments of the invention in detail.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0015] FIG. 1A , is a top view of a prior art, cup-shaped flex-spline member for a harmonic device;
[0016] FIG. 1B , is a cross-sectional view, taken on lines 1 B- 1 B of FIG. 1A ;
[0017] FIG. 2 , is a schematic diagram of the preferred embodiment of the harmonic motor of the present invention; and
[0018] FIG. 3 , is a schematic diagram similar to that of FIG. 2 , but where the harmonic motor is de-activated.
[0019] Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to illustrate and explain the present invention. The exemplification set forth herein illustrates an embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The present invention is intended for application in varied automotive vehicle applications and will be described in that context. It is to be understood, however, that the present invention could be successfully applied in many other applications. Accordingly, the claims herein should not be deemed limited to the specifics of the preferred embodiment of the invention described hereunder.
[0021] Known harmonic motors and gear systems typically have a cup-shaped flex-spline that, in application, is mechanically coupled to an associated input or output member to transmit forces created by the associated gear system. Referring to FIGS. 1A and 1B , a known cup-shaped flex-spline 10 is illustrated. Flex-spline 10 comprises a cylindrical sidewall 12 and a bottom wall 14 integrally formed therewith. A nominally right angle corner, indicated generally at 16 , continuously circumscribes the bottom wall 14 . The open upper portion of side wall 12 defines a rim 18 which is thickened to form radially outwardly facing gear teeth 20 extending continuously circumferentially thereabout for engagement with opposed teeth of a mating gear (not illustrated).
[0022] Flex-spline 10 is formed with the sidewall 12 assuming a circular configuration when in the unloaded condition. In application, the upper portion of the sidewall 12 , including the rim 18 and gear teeth 20 , is loaded into an ellipsoid configuration, illustrated in phantom, wherein the rim alternately flexes inwardly and outwardly during rotation of flex-spline 10 . Additionally, the bottom wall 14 tends to “oil can” axially inwardly and outwardly at the same time. In addition to imposing high parasitic losses and inefficiencies, the reciprocal “tilting” or bending of the upper portion of the side wall 12 inwardly and outwardly creates stress risers at corner 16 which can work-harden the material, leading to fracture and failure of the mechanism. The only practical design implementation to address this shortcoming is to increase the axial length of the flex-spline 10 . Although this partially mitigates the flexing problem, there remains a limit to the axial length of the gear teeth 20 , resulting in relatively high force loads and moments which must be reinforced by increasing package size and material costs. Furthermore, the cyclical tilting of the side wall 18 and gear teeth 20 results in rotational misalignment of gear teeth 20 with any mating teeth (not illustrated), thereby increasing unit loading and wear. This rotational misalignment is illustrated as offset angle θ in FIG. 1B .
[0023] Referring now to FIG. 2 , a preferred embodiment of the presently inventive harmonic drive motor 22 is illustrated. The harmonic drive motor 22 includes a first annular member 24 , a second member 26 , a third member 28 and means 30 for flexing the first annular member 24 . The first annular member 24 has a longitudinal axis 32 (seen as a point in FIG. 2 ). The first annular member 24 lies on a plane 34 corresponding to the plane of the drawing sheet and normal to the longitudinal axis 32 .
[0024] The first annular member 24 is cylindrically tube-shaped, defining radial inner and outer surfaces 36 and 38 , respectively. Both ends of first annular member 24 are parallel to plane 34 and are open in both axial directions. Inner surface 36 forms a plurality of radially inwardly extending gear teeth 40 which are substantially equally circumferentially spaced. Outer surface 38 forms a plurality of radially outwardly extending gear teeth 42 which are substantially equally circumferentially spaced. Gear teeth 40 and 42 are similarly shaped and dimensioned, are mutually parallel and extend the entire axial length of the first annular member 24 . First annular member 24 is formed of material, which allows it to be easily flexed radially inwardly and outwardly from its normal or relaxed round configuration illustrated in FIG. 3 . For example, first annular member 24 can be a molded composite of hard rubber or reinforced Nylon combined with particles of ferromagnetic material in sufficient quantity to enable localized magnetic attraction/repulsion of regions or circumferential segments of the first annular member 24 to effect deflection thereof as illustrated in FIG. 2 . Although flexible radially, the first annular member is relatively rigid in the circumferential direction.
[0025] The second member 26 is a nominally round and relatively rigid cylinder having an inwardly facing circumferential surface 44 forming a plurality of radially inwardly extending gear teeth 46 which are substantially equally circumferentially spaced. Gear teeth 46 of second member 26 are shaped and dimensioned to selectively cooperatively engage gear teeth 42 of first annular member 24 as is described herein below. The second member 26 is preferably constructed of aluminum, reinforced Nylon, or other suitable non-ferrous material. The second member 26 is arranged concentrically with first annular member 24 for rotation about longitudinal axis 32 . Gear teeth 46 extend the entire axial length of the second member 26 to maximize the operating contact surfaces between cooperating adjacent gears 42 and 46 . As is best illustrated in FIG. 3 , first annular member 24 and second member 26 are dimensioned to permit radial clearance between the tips of gears 42 and 46 , respectively, wherever the first annular member 24 is in the relaxed position.
[0026] The third member 28 is a nominally round and relatively rigid cylinder having an outwardly facing circumferential surface 48 forming a plurality of radially outwardly extending gear teeth 50 which are substantially equally circumferentially spaced. Gear teeth 50 of third member 28 are shaped and dimensioned to selectively cooperatively engage gear teeth 40 of first annular member 24 as is described herein below. The third member 28 is preferably constructed of aluminum, reinforced Nylon, or other suitable non-ferrous material. The third member 28 is arranged concentrically with the first annular member 24 about the longitudinal axis 32 . Gear teeth 50 extend the entire axial length of the third member 28 to maximize the operating contact surfaces between cooperating adjacent gear teeth 40 and 50 . As is best illustrated in FIG. 3 , first annular member 24 and third member 28 are dimensioned to permit radial clearance between the tips of gear teeth 40 and 50 , respectively, whenever the first annular member 24 is in the relaxed position.
[0027] The means 30 for flexing the first annular member 24 is preferably constructed as an electromagnetic actuator assembly, and herein after, is identified as such. Electromagnetic actuator assembly 30 includes a generally cylindrical armature body 52 fixedly mounted to a splined end of an axially elongated support member 54 . In application, support member 54 could extend axially in one or both directions beyond the axial ends of the first annular member 24 as well as the second member 26 to fix the electromagnetic stator assembly from displacement or rotation about longitudinal axis. Furthermore, support member can be employed to affix end closure members, seals, output shaft bearings and the like (all non-illustrated), depending upon the particular application intended.
[0028] Armature body 52 is generally spool-shaped, including axially leading and trailing outwardly extending flange portions (not illustrated). A plurality of electrical coils or windings 56 are insulatively disposed within armature body 52 and are each electrically in-circuit with a control system via electrical conductors to define a discrete number of circumferentially arranged magnetic poles. Armature body 52 is formed of ferrous material such as laminated or sintered steel or other suitable material. Although eight electrical coils 56 are illustrated, more or fewer can be applied, as the intended application dictates.
[0029] The third member 28 has an inwardly facing cylindrical surface 58 which forms an interference fit with an outwardly facing cylindrical surface 60 of armature body 52 . Thus, the third member 28 and the electromagnetic actuator assembly 30 are affixed in-assembly as a stator for relative non-rotation with respect to the first annular member 24 and the second member 26 .
[0030] As best viewed in FIG. 3 where the first annular member 24 is in the relaxed position, i.e. when none of the electrical coils 56 are electrically energized, first annular member assumes a substantially round configuration. Insodoing, radial spaces are established between opposed gear teeth 42 and 46 of first annular member 24 and second member 26 , respectively, as well as between gear teeth 40 and 50 of first annular member 24 and third member 28 , respectively. In this condition the second member 26 (motor rotor) is entirely mechanically de-coupled from the third member 28 and electromagnetic actuator assembly 30 (motor stator), as well as the first annular member 24 .
[0031] Referring to FIG. 2 , the harmonic motor functions by selectively energizing opposed coil pairs within the actuator assembly 30 . For example, if an opposed pair of coils 56 C and 56 D are energized, they create a magnetic field, which attracts 90° offset portions of the flexible first annular member 24 , causing it to distend into an elliptical or egg-shaped configuration. The portions of the first annual member 24 adjacent coils 56 A and 56 B are drawn radially inwardly into intimate contact with the outer peripheral surface 48 of third member 28 , wherein gear teeth 50 of third member 28 engage gear teeth 40 of first annular member 24 . Such points-of-contact or engagement are designated by brackets 62 and 64 . Simultaneously, opposed (by 90°) portions of the first annular member 24 are forced radially outwardly into intimate contact with inner surface 44 of second member 26 , wherein gear teeth 42 of first annular member engage gear teeth 46 of second member 26 . Such points-of-contact or engagement are designated by brackets 66 and 68 . This engagement can be supplemented by magnetic repulsion of adjacent reverse polarized coils 56 C and 56 D.
[0032] As illustrated in FIG. 2 , second member 26 is interconnected with third member 28 for non-rotation by the first annular member or flex-spline interlock 24 . When the electrical coils are sequentially (ex.: circumferentially) energized, the localized points of contact 62 & 64 and 66 & 68 of the cooperating engaged gear teeth “walks around” the circumference of the harmonic motor 22 , thereby effecting relative rotation between the second member 26 and the third member 28 .
[0033] The electrical control of harmonic motors and actuators is well known. For example, U.S. Pat. No. 6,664,711 B2 and U.S. patent Application 2005/0253675 A1 describe harmonic motors and controllers therefore which can be adopted for use in the present invention. U.S. Pat. No. 6,664,711 B2 and U.S. 2005/0253675 A1 are hereby incorporated herein by reference as an exemplary teaching of one possible approach. It is to be understood that they reflect only one of many possible control strategies. Furthermore, other methodologies for sequentially flexing the first annular member such as mechanical, electrical or electromagnetic could be implemented without departing from the spirit of the invention.
[0034] In the present harmonic motor, the gear teeth are parallel to the motor axis. This will result in the flex-spline rotating in the same direction as the outer gear since the flex-spline inside gear teeth would have more teeth than the matching armature gear teeth. The overall effect will be an approximate doubling of the motor output torque for the same actuation.
[0035] It is to be understood that the invention has been described with reference to specific embodiments and variations to provide the features and advantages previously described and that the embodiments are susceptible of modification as will be apparent to those skilled in the art.
[0036] Furthermore, it is contemplated that many alternative, common inexpensive materials can be employed to construct the basis constituent components. Accordingly, the forgoing is not to be construed in a limiting sense.
[0037] The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used is intended to be in the nature of words of description rather than of limitation.
[0038] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. For example, . . . It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for illustrative purposes and convenience and are not in any way limiting, the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents, may be practiced otherwise than is specifically described.
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A harmonic drive motor includes a first annular member, concentric second and third members, and a device for flexing the first annular member. The first annular member has a longitudinal axis and is flexible. The second member is relatively rigid and is substantially coaxially aligned externally of the first annular member, and the third member is relatively rigid and is substantially coaxially aligned internally of the first annular member. One of the second and third members is rotatable about the longitudinal axis and the other is relatively non-rotatable. The flexing device flexes the first annular member into at least two spaced-apart points of contact with the inner diameter surface of the second member and into at least two spaced-apart points of contact with the outer diameter surface of the third member. The flexing device sequentially flexes the first annular member to rotate both sets of at least two points of contact about the longitudinal axis which effects relative rotation between the second and third members.
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FIELD OF THE INVENTION
[0001] This invention relates to systems and methods for controlling power semiconductor switching devices.
BACKGROUND TO THE INVENTION
[0002] The power semiconductor switching devices with which we are concerned typically have a current carrying capability of greater than 1 amp and are operable with a voltage of greater than 100 volts. Embodiments of the devices with which we are concerned are able to carry currents of greater than 10 amps, 50 amps or 100 amps and/or are able to sustain a voltage difference across the device of greater than 500 volts or 1 KV.
[0003] Examples of such devices include insulated gate bipolar transistors (IGBTs), as well as FETs such as MOSFETS (vertical or lateral) and JFETs, and potentially devices such as LILETs (lateral inversion layer emitter transistors), SCRs and the like. The techniques we will describe are not limited to any particular type of device architecture and thus the power switching devices may be, for example, either vertical or lateral devices; they may be fabricated in a range of technologies including, but not limited to, silicon, and silicon carbide.
[0004] Switching devices of this type have applications which include switching in high voltage transmission lines, in particular dc transmission lines of the type which may, for example, carry power from an offshore wind installation, and medium voltage (for example greater than 1 KV) switching for motors and the like, for example locomotive motors.
[0005] In applications of this type typically tens or hundreds of devices may be connected in series and/or parallel to operate at the desired voltages/currents. Controlling the switching of such devices presents particular problems, because the electrical environment is relatively noisy and because the voltages/currents being switched are large, leading to a significant risk of device failure. Moreover when one device in such a system fails, other switching devices in the system can easily fail as a consequence.
[0006] We will describe techniques which address these and other problems.
SUMMARY OF THE INVENTION
[0007] According to the present invention there is therefore provided a power semiconductor switching device control system for controlling a plurality of power semiconductor switching devices to switch in synchronisation, the system comprising: a coordinating control system; and a plurality of switching device controllers each coupled to said coordinating control system; wherein each said switching device controller is configured to control one or more respective said power semiconductor switching devices into a plurality of states including a fully-off-state, a saturated-on-state, and at least one intermediate state between said fully-off state and said saturated-on state; wherein said coordinating control system is configured to control said switching devices to switch in synchronism by controlling said switching device controllers; and wherein said coordinating control system is further configured to: control said switching device controllers to control said power semiconductor switching devices from an initial state comprising one of said fully-off state and said saturated-on state into said intermediate state; maintain said power semiconductor switching devices in said intermediate state to synchronise switching of said devices; and then control said switching device controllers to control said power semiconductor switching devices from said intermediate state into a final state comprising the other of said fully-off state and said saturated-on state.
[0008] An embodiment of such a control system enables the switching of more than 10, 100 or 1000 power semiconductor switching devices to be performed quickly, but also in a controlled, synchronised manner. Thus, broadly speaking, in embodiments of the control system the conduction state of each device is controlled in discrete steps so that the conduction states of the devices change in lockstep. As well as synchronising the switching, this also helps to ensure that the current/voltage load is shared between the devices rather than, for example, one of the devices in a series string bearing the entire voltage across a string. Such a technique may be employed with any semiconductor switching device but is particularly advantageous when the power semiconductor switching devices comprise IGBTs (insulated gate bipolar transistors).
[0009] In preferred embodiments of the system the devices are controlled between a plurality of intermediate states these may include, in particular, a state in which a device is maintained at a low-current plateau. Such a low-current plateau may comprise, for example, a current of order 0.1-1 Amp, intermediate between the approximately zero (leakage) off-current and an on-current which may be of order 100 Amps. A second intermediate state which may additionally or alternatively be employed is an active low-voltage plateau state in which the voltage across a device is maintained at an intermediate value between a fully-off voltage and a saturated-on voltage of the device, for example of order 10-100V where the saturated-on voltage may be less than 3 volts and the off-voltage of order 1 KV. The low-current plateau is employed to ensure that parallel connected devices are all active, and the low-voltage plateau is employed to ensure that series connected devices are all active. When devices are active they can respond rapidly to changes in gate charge and this is necessary for synchronised switching. In embodiments described later there may be up to six different states for the devices.
[0010] In preferred embodiments the coordinating control system transmits a control signal to the switching device controllers of at least the power semiconductor switching devices to be switched, and then waits until an acknowledgement signal has been received confirming that each device is in the requested state, before sending a further control signal to progress the relevant devices to the next (intermediate or final) state. This form of active control of the switching devices is particularly robust. In embodiments the control and/or acknowledgement/confirmation signals may comprise data packets sent over a packet data communications network. In this case a control signal may comprise a broadcast packet including a group address field for selecting a set of the switching devices for control together with a switch state field defining the next target state. In embodiments of the system these data packets comprise real time data packets; that is they are labelled to be treated as ‘real time’ and given priority over other data packets which may be sent over the network.
[0011] In a preferred system architecture the coordinating control system comprises a central controller coupled to one or more sub-controllers, and each such sub-controller is coupled to a set of device controllers, for example 10 or more device controllers. In this architecture the central controller may be coupled to the sub-controllers via one or more shared buses, but preferably each sub-controller has a separate bus connection to each of the switching device controllers it controls. In embodiments each switching device controller controls one or more power semiconductor switching devices. An architecture of this general type facilitates rapid broadcasting of switch control information, but also facilitates rapid handling of messages between a sub-controller and the switching device controllers to which it is coupled. In particular the dedicated buses for the switching device controllers facilitate combining acknowledgement/confirmation signals from the switching device controllers so that it can easily be determined when all reach the next target state and/or whether any faults are flagged.
[0012] The invention also provides, separately, a switching device controller, and a coordinating control system according to aspects/embodiments of the invention.
[0013] Thus in a related aspect the invention provides a coordinating control system for controlling a plurality of switching device controllers each coupled to the coordinating control system for switching a plurality of power semiconductor switching devices in synchronism, wherein each said switching device controller is configured to control one or more respective said power semiconductor switching devices into a plurality of states including a fully-off state, a saturated-on state, and at least one intermediate state between said fully-off state and said saturated-on state, the coordinating control system comprising: a system to control said power semiconductor switching devices to switch in synchronism by controlling said switching device controllers; wherein said system to control said power semiconductor switching devices is configured to: control said switching device controllers to control said power semiconductor switching devices from an initial state comprising one of said fully-off state and said saturated-on state into said intermediate state; maintain said power semiconductor switching devices in said intermediate state to synchronise switching of said devices; and then control said switching device controllers to control said power semiconductor switching devices from said intermediate state into a final state comprising the other of said fully-off state and said saturated-on state.
[0014] The skilled person will appreciate that a coordinating control system of this type may be implemented in hardware or in software (provided on a physical carrier such as a disk), for example running on a digital signal or other processor, or on a combination of the two. Further, code for implementing aspects/embodiments of the invention may comprise code for a hardware description language. The skilled person will also appreciate that, in embodiments, the coordinating control system may be distributed over a plurality of coupled components in communication with one another.
[0015] The invention further provides a method of controlling switching of a plurality of power semiconductor switching devices, starting with each device in an initial state comprising one of a saturated-on and a fully-off state, the method comprising: controlling said power semiconductor switching devices to transition from said initial state to one or more intermediate states between said saturated-on state and said fully-off state; holding said power semiconductor devices in said one or more intermediate states to align said devices in said one or more intermediate states; and then controlling said power semiconductor switching devices to transition from said aligned state to a final state comprising one of said saturated-on and said fully-off state.
[0016] The invention still further provides a power semiconductor switching device control system for controlling a plurality of power semiconductor switching devices to switch in synchronisation, starting with each device in an initial state comprising one of a saturated-on and a fully-off state, the system comprising: means for controlling said power semiconductor switching devices to transition from said initial state to one or more intermediate states one or more intermediate states between said saturated-on state and said fully-off state; means for holding said power semiconductor devices in said one or more intermediate states to align said devices in said one or more intermediate states; and means for controlling said power semiconductor switching devices to transition from said aligned state to a final state comprising one of said saturated-on and said fully-off state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 shows an example of a switching device controller (SD) in combination with a coordinating control system comprising a central controller coupled to a sub-controller according to an embodiment of the invention;
[0018] FIGS. 2 a and 2 b show, respectively, a power semiconductor switching device control system according to an embodiment of the invention in an example for bridge application, and details of the arrangement of FIG. 2 a;
[0019] FIGS. 3 a to 3 c show, respectively, an example of a gate voltage against gate charge curve for a power semiconductor switching device illustrating six defined states and five transitions of the device, and a corresponding table of the states and transitions, and graphs of collector current and collector-emitter voltage against time for switch-on of an IGBT (insulated gate bipolar transistor) power semiconductor switching device;
[0020] FIGS. 4 a and 4 b show, respectively, first and second example communication topologies for power semiconductor switching device control systems according to embodiments of the invention;
[0021] FIGS. 5 a to 5 c show, respectively, a conceptual illustration of a scheme for processing data packets at a sub-controller sent by a plurality of switching device controllers connected to the sub-controller, an example illustration of device addressing within a small control system network, and a block diagram of a sub-controller for a power semiconductor switching device control system according to an embodiment of the invention; and
[0022] FIGS. 6 a to 6 c show, respectively, details of a pair of configuration register banks for a switching device controller according to an embodiment of the invention, an illustration of a procedure for writing non-real-time data in data packets sent from the coordinating control system to an addressed device, and an illustration of a complementary non-real-time data read procedure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] Referring to FIG. 1 a , an embodiment of a power semiconductor switching device control system 100 comprises a central controller 110 coupled to a plurality of sub-controllers 120 of which one is illustrated, in turn coupled to a plurality of switching device controllers 130 (again just one is illustrated). In the following description the switching device controller 130 is sometimes referred to as a switch device (SD); and the central controller and sub-controller are sometimes abbreviated to CC and SC respectively. Although in the example of FIG. 1 a a sub-controller is provided, this is not essential and embodiments of the control system may employ just a central controller. Other embodiments of the control system may employ multiple levels of (nested) sub-controllers.
[0024] A power electronics system or circuit generally comprises a plurality of switches each of which may comprise one, or typically multiple switching devices.
[0025] In the example of FIG. 1 a the power semiconductor switching device is an IGBT 132 , although other devices such as MOSFETs, JFETs and the like may also be employed.
[0026] As illustrated, the switching device controller (switch device) 130 comprises digital logic to interface with a bus 122 connecting the device controller 130 to the sub-controller 120 . In preferred embodiments the device controller 130 also receives power over this bus and the digital logic 140 includes a circuit to derive power from the bus for powering the low voltage portions of the device controller/switch device 130 . In operation the digital logic 140 receives commands and configuration information over bus 122 and replies with acknowledgement and other data as described in more detail later.
[0027] The digital logic 140 interfaces with analogue control circuitry 138 coupled, in the illustrated example, to a gate driver 136 , driving IGBT 132 . We have previously described, in our UK patent application GB1103806.4 filed on 7 Mar. 2011 (hereby incorporated by reference) some example IGBT driving circuits. A particularly preferred circuit is described in our co-pending UK patent application, filed on the same day as this application, and entitled “Power Semiconductor Device Controllers” (hereby incorporated by reference). This employs combined current and voltage feedback as illustrated in FIG. 1 , together with an active control system such that the switching device (IGBT) effectively looks like a passive resistor. Thus two active intermediate states are defined by a target resistance value, a high resistance value for an active low current state, and a low resistance value for an active low voltage state (states 3 and 4 described later). Preferably a second control loop is also provided in the controller to servo the gate voltage to threshold values, one just below that at which the device starts to switch on, a second just above that at which the device starts to come out of saturation (states 2 and 5 described later).
[0028] More generally, preferred embodiments of the switching device controller 130 of FIG. 1 a include a voltage sensing circuit 142 to sense a voltage on the semiconductor switching device and a current sensing circuit 144 , to sense a current passing though the device. In some preferred embodiments data from either or both of these sensing circuits is fed back, optionally on request, to one or both of the sub-controller 120 and central controller 110 .
[0029] In an electrical power converter such as a full (H-) bridge, half bridge or 3-phase inverter, each switch position may comprise one or more semiconductor switching devices. In high voltage and/or high current applications of the type described in the introduction many semiconductor switching devices may be connected in series and/or parallel, each with a respective switching device controller. FIG. 2 a shows an example of an H-bridge electrical power converter 200 which may be employed, for example, for converting DC to AC or vice versa. In this example each switch 202 a - d of the H-bridge 204 comprises a set of semiconductor switching device dies, as shown in more detail in FIG. 2 b . In the expanded diagram of FIG. 2 b a single controllable switch 202 comprises 9 power semiconductor switching devices 210 , for example each comprising a silicon carbide die, multiple devices being connected in parallel to create a voltage level, sets of multiple devices then being connected in series to series-connect the voltage levels. In other embodiments a single switching device controller may control two or more switches or device dies). Each switch 210 has a respective switching device controller 130 which, in turn, is coupled to one of the sub-controllers 120 a, b.
[0030] As illustrated a separate bus runs between a sub-controller and a switching device controller so that there is one such bus for each switching device controller. In one exemplary embodiment a sub-controller provides 30 separate bus connections to respective switching device controllers and thus for the example H-bridge of FIG. 2 a , which employs 36 semiconductor switches, two sub-controllers are employed. The skilled person will recognise that in a high-voltage and/or current power electrical circuit with multiple switches hundreds or potentially thousands of semiconductor switching devices may be employed. In such an arrangement the power semiconductor switching devices should be connectable in series and in parallel and the switching device controllers system should be able to control the switching of these devices so that they switch in synchronism, in effect substantially simultaneously.
[0031] To facilitate simultaneous control a number of switch states are defined. In one example embodiment these are as follows, (although more or fewer states may be employed in ultimate implementations);
State 1: FULLY OFF—the switch is turned off, only leakage current flows State 2: OFF WITH LOW GATE VOLTAGE—the switch is turned off but close to the gate threshold voltage State 3: ACTIVE LOW CURRENT—the switch is active but in a state where there is a defined low current flowing through the device. State 4: ACTIVE LOW VOLTAGE—the switch is active but in a state where there is a defined low voltage (above the saturation voltage) across the device State 5: ON WITH HIGH GATE VOLTAGE—the switch is turned on and in saturation but may not be fully saturated State 6: SATURATED ON—the switch is in a saturated on condition
[0038] In the active low current state there may be a high voltage across the device but potentially there may be any voltage across the device (this may even be negative if a reverse parallel diode is conducting because current is reversed through switch, as can occur when driving inductive loads). In the active low voltage state there may be near to full current going through the device, but again in principle there may be any current flowing through the device in this state.
[0039] Communication of the required switch state is by real-time messages from the central controller to the switching devices. In addition configuration and monitoring data can be exchanged by non-real-time messages.
[0040] In broad terms when the device is off there will be a high voltage across the device, for example 1 KV, and substantially zero current (just the leakage current) and, for example, substantially zero gate voltage. Injecting current into the gate increases the gate voltage a little so that it begins to pass a small current, for example of order 0.1-1 amp; this effectively makes series-coupled devices simultaneously active. To achieve this state may take, for example, of order 50 ns-1 μs, taking into account the time to charge the gate, and propagation delays. From this state, further injection of current into the gate further increases the gate voltage to reach a state where the device is passing substantially more current, for example of order 100 amps, and there is still a residual or ‘active’ low voltage across the device, for example of order 10 volts. Eventually the gate voltage is driven to its full voltage which may be, for example, of order 15 volts for a silicon device or 20 volts for a silicon carbide device, at which point the device is saturated, passing its full current and has a minimal, saturated-on voltage across the device, for example of order 2 volts.
[0041] The above outline description is, in embodiments, a simplification of the various hold states and transitions that are employed, in particular with an IGBT power semiconductor switching device. Thus referring to FIGS. 3 a and 3 b , six states labelled 1-6 may be employed with 5 transition regions, labelled A-E in between. The table in FIG. 3 d describes these states and transitions: in states 1 and 2 the device is OFF; in states 3 and 4 the device is in an intermediate, ‘active’ state, and in states 5 and 6 the device is ON.
[0042] More particularly in state 1 the gate-voltage V g =0 or negative, depending on whether the device is switched off with a zero or negative gate voltage. In state 2 the gate voltage is equal to a first (low) threshold voltage: V g =V th (low), with the gate voltage rising during transition A. In state 3 the collector current of the IGBT is a defined minimum value I min that is I c =I min . In state 4 the collector-emitter voltage is a defined, minimum voltage value V min , that is V ce =V min . Transition B moves from state 2 to state 3 and transition C from state 3 to state 4. In state 5 the gate voltage is equal to a second (high) threshold voltage, that is V g =V th (high), and in state 6 the gate voltage is a maximum, saturated voltage V s , that is V g =V s , with transition E between states 5 and 6. In moving between states 1 and 6 the device switches from fully OFF to saturated ON (and vice versa). At each state a switching device controller receives a state change command from a central or sub-controller to transition to an adjacent state and then sends an acknowledgement when the transition is complete. The central or sub-controller awaits the acknowledgement from all nodes before proceeding to send out the command for the next state change. Because movement between the states is reversible, a device or group of devices can be moved back from a purported state to an earlier state, for example to return (or alternatively move forward) a set of switching devices to a known good state should a fault be indicated or detected.
[0043] Thus in embodiments a central or sub-controller may send a RT packet to a switching device controller (also described later as a ‘node’) requesting a state change to one of six states. A node sends back an acknowledgement when it has completed a state transition and this information tells the controller when all the connected nodes have achieved the desired state.
[0044] As illustrated in FIG. 3 b the 6 states can be broken down into 3 regions each of 2 states, OFF, active and ON, with transitions between the states.
[0045] In embodiments this information is encoded by 4 data bits, for example, 4 successive data bits within a real-time packet. The return packet has one flag to indicate that a transition between two states is in progress. A controller can then ‘OR’ together or bit-by-bit, the packets as they arrive from each node to create a composite packet. In this way, it any one node is still in transition, the combined effect is that the state of the whole block is still in transition, until the very last node has completed its transition to the next state.
[0046] As described further later, as well as this four bit payload, a data packet may also include additional payload data bits and preferably at least one packet type (T) bit to define at least two different types of packet, a real-time packet and a non-real-time packet. In preferred embodiments a packet also includes at least one receive error flag and/or at least one flag indicating that the packet is valid. Preferably a packet further includes one or more bits in addition to the previously described data bits for an error detecting (and possibly correcting) code.
[0047] As well as real-time switch control data, data sent from a controller to a node may also comprise non-real-time configuration data and optionally other data such as status change data defining a global system status such as a command to enter a sleep mode, shutdown mode and the like. This status change data (called action command) is preferably sent as real-time data. Data returned from a node to a controller may comprise real-time switch acknowledgement data as previously described, non-real-time monitoring data, and status or warning data such as over current data over-voltage, or over-temperature data (sent real-time). As previously mentioned a packet type flag may be used to indicate real time data such as switch control/acknowledgement data, for example a zero defining a real-time packet and a one defining a non-real-time packet. In embodiments an additional packet type bit is employed to define a packet sub-type, in particular for non-real-time data packets. Non-real-time data packets may comprise, for example, configuration or monitoring data. Since this latter data type may employ larger payloads, optionally one or more sequence data bits may be employed to define a NRT message. Referring now to FIG. 3 c , this shows schematic sketches of collector current I c and collector current emitter voltage V ce against time for an IGBT as it moves through the 6 states previously described starting with an initial switch-on command and ending with switch-on complete at hold state 6. Thus, as can be seen, in the initial free OFF state 1 I C is at 0 amps and transitions to I min at hold state 3, which may be of order 0.1-1 amp, then increasing towards a maximum during transition state C. Also during transition state C, V ce falls to a low voltage V min (at state 4), for example of order 10-50 volts, that is greater than the saturated-on saturation voltage. During transition state D, V ce falls to the final, saturated-on saturation value V s which may be, for example, of order 1 to 5 volts. Thus at hold state 6 the device is saturated ON. The switch OFF sequence is essentially the reverse of that illustrated in FIG. 3 c.
[0048] Broadly speaking, and as previously outlined, the task of the Central Controller is to orchestrate the switching of all Switch Devices in a power converter. It does this via a two level communication system:
[0049] A real-time (RT) data packet system that ensures the timely arrival of real-time state-change commands and the return of real-time status and fault flags.
[0050] A non-real-time (NRT) messaging service is used for configuring Switch Devices and transporting time-stamped monitoring data back to the Central Controller.
[0051] The Central Controller has a number of ports which can be arbitrarily connected to Switch Devices or Sub-Controllers, but preferably each port maps in some way to the topology of the converter. The ports on the Central Controller are addressed in hardware, and as such, data packets may be sent out and received on these ports independently and asynchronously to one another.
[0052] As described previously each port has two channels, “A” and “B”, for redundancy; these can also be used independently. The Central Controller has the capability to orchestrate simultaneous NRT (non-real-time) message transactions. This dual channel set-up can also be used to assist with RT data error checking: The switch devices receive the same RT data on two channels simultaneously and each switch device compares these two received packets to ensure the RT data is identical before committing to an action. The Central Controller can also apply this approach to received packets, since the RT data part of the packets should be identical. It should be noted however the NRT part of the packets from channels A and B will not be the same if they are being used independently for NRT message transactions to different devices on the same port.
[0053] In embodiments all ports may be half-duplex: a data packet is sent from the Central Controller to Sub-Controllers and Switch Devices, and a return packet is then sent from all of the receiving Switch Devices to the Central Controller. This is one complete packet exchange. The Central Controller initiates the packet exchanges and the Switch Devices are given a time window within which to send their reply.
[0054] The NRT messages are handled in a similar way: The Central Controller initiates a message transaction by exchanging a series of data packets until a complete message is sent. The message may contain the address of a single Switch Device, Sub-Controller, or of a group of Switch Devices. The addressed device(s) process the message and may reply with their own message (but only one device may reply on one hardware port/channel at any one time). Thus the Central Controller keeps the port/channel open awaiting the reply from the Switch Device that received the NRT message if a reply is expected. When the Switch Device has sent a reply message, the message transaction is complete.
[0055] The Central Controller may have to wait for the Switch Device to send a reply message, during which time the port/channel is locked and may not be used to send or receive NRT messages to or from any other Switch Device. However, the Central Controller is free to have other message transactions simultaneously open on the other available hardware ports and channels.
[0056] Broadly speaking the function of the Sub-Controllers is to pass on data packets from the Central Controller to the Switch Devices, and merge the data from the returning data packets. This task is preferably performed quickly, on a bit-in bit-out basis, without waiting for the complete data packet to arrive. The Sub-Controllers may alter the contents of the out-going packet data on a bit-by-bit basis to perform tasks in either direction.
[0057] Again, each sub-controller has a number of ports with, in embodiments, each port having two channels, “A” and “B”, for redundancy. As such, the Sub-Controllers and Central Controller may have similar interfaces and/or comprise similar hardware. In embodiments power and communications is routed through these port connections.
[0058] In embodiments an addressing scheme (described later) ensures each Sub-Controller and Switch Device has a unique address. Selection of channel A or B is preferably carried out automatically by the Central Controller and is not part of the addressing scheme (since both channels route to the same end Switch Devices). Even though the first tier of ports in the Central Controller is addressed via hardware routing, this first level enumeration is preferably included in the message address for the purposes of routing and checking.
[0059] By way of example, to address a system with a 4-level communications architecture, a 20-bit address is employed. An inverter with 3 phase-legs might be configured as follows:
[0060] Level 1: Central Controller Ports 1->4 connect to four Primary Sub-Controllers on half-phase-leg 1H, ports 5->8 connected to four Primary Sub-Controllers on half-phase-leg 1L, and so on for phases 2 & 3 (i.e. ports 1->24).
[0061] Level 2: Primary Sub-Controllers each connect to 24 Secondary Sub-Controllers (i.e. 1.1->24.24).
[0062] Level 3: Secondary Sub-Controllers connect to a further 24 sub-levels, making 2304 levels in total per half-phase-leg (i.e. 1.1.1->24.24.24).
[0063] Level 4: Tertiary Sub-Controllers connect to 24 paralleled Switch Devices each, making a total of 331776 connected Switch Devices (i.e. 1.1.1.1->24.24.24.24).
[0064] Such a system represents a level of connectivity suitable for creating a +/−1 MV HVDC system with 2400A capability out of 1 kV/100A Switch Devices.
[0065] Note that this addressing scheme is for NRT messages only and, in embodiments, is not used in RT data packet delivery.
[0066] In embodiments all Switch Devices receive all data packets on a given Central Controller port and then reply with their own data packet (which the Sub-Controllers merge en-route back to the Central Controller). Only one Switch Device per Central Controller port/channel is permitted to reply with a packet that contains non-null NRT data at any one time. If this does occur, then Sub-Controller that receives the two NRT data chunks inserts a logic 1 “Merge Error” flag into the return packet to alert the Central Controller that a communication error has occurred. (A data chunk comprises one or more bits and may be less than a byte or an 8-bit byte).
[0067] Similarly in embodiments all messages on a given Central Controller port are received by all Switch Devices.
[0068] As previously described, each Switch Device contains a combination of digital and analogue circuitry to ensure the power device (IGBT or MOSFET) moves through each of the 6 switch states.
[0069] If a switch contains only a single Switch Device there may be no need for the ACTIVE_LOW_CURRENT and ACTIVE_LOW_VOLTAGE states as these are used to synchronise multiple Switch Devices.
[0070] State 3: ACTIVE_LOW_CURRENT is used when there is a high voltage across the power devices. This controlled low current state ensures there is low power dissipation during turn on when the power device is active.
[0071] State 4: ACTIVE_LOW_VOLTAGE is used when there is high current flowing in the power devices. This controlled low voltage state ensures there is low power dissipation during turn off when the power device is active.
[0072] Referring next to FIG. 4 a , this shows the topology of a first example topology of a power semiconductor switching device control system 400 , illustrating a first arrangement of redundant channels. In the example of FIG. 4 a a central controller 402 has a plurality (for example 30) of logical outputs/inputs 404 each split into a pair of redundant channels A and B 404 a, b . The system also includes a plurality of sub-controllers 406 , separate sub-controllers handling the A-channels and the B-channels, to provide redundancy in case of a sub-controller failure, each switching device controller (SD) 408 has two redundant inputs/outputs 410 a, b , one for each of the A and B channels. In embodiments multiple layers of sub-controllers may be employed, for example up to three layers of sub-controller.
[0073] In the illustrated example, the connections between each device/controller are high speed point-to-point links, but in alternative arrangements a shared bus may be employed between the central controller and the sub-controllers. In one embodiment a connection comprises a twisted copper wire pair; the same pair or an additional pair may be employed to provide a power supply to the switching device controllers. Alternatively a fibre optic connection may be employed between the central controller and sub-controller(s) and/or to/from a switching device controller. Such arrangements enable high speed data transfer, for example greater than 100 Mbit/s or 1 Gbit/s. A network connection 412 is also provided to the central controller 402 for overall configuration/control of the system; in embodiments this may be an Ethernet connection.
[0074] FIG. 4 b , in which like elements to those of FIG. 4 a are indicated by like reference numerals, illustrates a second example topology in which both the A and B channels from the central controller to a switching device controller are handled by the same sub-controller. Although this reduces the redundancy it has some other advantages, such as simplified wiring and a reduced chance of a device being connected to different addresses on networks A and B. Either topology may be employed.
[0075] From the above description the skilled person will appreciate that the topology of the switching device control system allows a single central controller to control, potentially, a large number of power semiconductor devices via a tree structure, where each node in the tree is allocated an address, as described later, to facilitate passing non-real time messages. A communications protocol operates over this tree, preferably to provide the following features: a mechanism for transmitting short real-time requests from the central controller to the switching device controllers, and to receive an indication of when such a request has been completed, with as small as possible overall communications latency—to synchronise the switching of a group of power semiconductor switching devices. A mechanism for the central controller to receive high-level fault information from the switching device controllers, again preferably with as short a delay as practicable—this is used to detect fault conditions in order to take corrective action. A mechanism for the central controller to interrogate the switching device controllers (SDs) and sub-controllers (SCs) for fault diagnosis, initial device configuration, and to read measurement data for fault prognosis and the like—this may employ longer potentially multibyte transactions and need not be ‘real-time’. The communications protocol will in general be operating in an electrically noisy environment, with a relatively high degree of electrical isolation between communicating nodes.
[0076] In order to support the low-latency real-time requirement the protocol uses a short frame structure and a request/response protocol. The CC sends a single frame out to all devices, the SC forwards this on to all its output ports, the SDs receive this. The SDs send an immediate response, the SCs receive these from all ports and merge before sending the merged response back to the CC. This is asymmetric: the SCs receive a single data frame from above and broadcast it out on all ports; they receive multiple data frames from below and merge these together before sending a single frame upwards.
[0077] The short frame length used for low-latency does not directly enable the NRT (non-real time) messaging where a request or response might require multi-byte packets to be transmitted. In order to achieve this, a higher-level protocol is required where an NRT transaction is split over many short frames.
[0078] An example low-level frame structure is described later; some features are:
the downstream (CC to SD) and upstream (SD to CC) frames are different, both in contents and in their size. both frames contain a Hamming code to allow for error detection and correction. a type bit (T) in the downstream frame indicates whether it contains real-time (RT) and non-real-time (NRT) data. the upstream frame contains both RT and NRT data (i.e. there is no type bit).
[0083] The CC is responsible for prioritising RT traffic over NRT traffic at all times. Thus a state change will take priority over NRT data. A SD does not prioritise sending (RT) fault data over sending NRT data (since otherwise a node that was in a fault state could not be examined using the NRT mechanism) and so both RT and NRT data are present in the upstream frame.
[0084] The choice of a Hamming code (over the more conventional CRC) is to reduce the delay within the SC when it is merging frames from below and to provide a degree of error correction.
[0085] Real-time requests are sent from the CC to all devices within a real-time group (of which there are 32 in one embodiment). The request is that all SDs in this group should either change switching state, or should perform some real-time action. The real-time response contains “state change in progress” and “action in progress” bits to indicate when the switch or action has completed, and fault flags to indicate the fault state of the SD.
[0086] SCs performs an OR operation on these bits from all downstream nodes in order to provide a “subsystem status” to the CC. If the CC issues a state change it can determine that all devices have completed that operation when the SIP bit becomes clear. An example RT frame is described later.
[0087] In embodiments, the round-trip delay time for a real-time packet is less than a time taken to transition between two (intermediate) states of the switching device. It is further preferable that the round-trip delay time is not greater than a failure time for the switching device; preferably the round-trip delay time is of order ten times less than this. A typical failure time is ˜1-10 μs (for example a short circuit time can be determined from the device datasheet; this may be dependent on the operating conditions of the device). In general the state of a switching device changes on a timescale ˜1 μs and it is therefore preferable that the signalling is able to operate faster than this.
[0088] Non-real-time requests are transmitted as multiple frames on the network. The NRT frame structure contains 8-bits of data and a bit to indicate whether this is an ordinary data byte, or is a control byte which indicates the message structure (e.g., a START or STOP signal, or a PAUSE used for flow-control). The downstream NRT frame also contains a sequence number (the asymmetric nature of the bus means this is not required upstream).
[0089] In embodiments only a single SD/SC can respond to a NRT request at a time so that data is not destroyed when merged at a SC. All other devices transmit a NULL-control packet that is defined to have all zero bits and thus can be merged harmlessly.
[0090] The CC uses the NRT layer to access registers within the SDs. The NRT message contains the NRT device address together with the type of operation (read or write) and the register address to access. For a write operation the data to write is also transmitted; for a read operation the number of registers to read is transmitted. The response from the SD/SC contains a status and, in the case of a read request, any required data.
[0091] The NRT addressing model preferably includes broadcast and group addresses to allow operations to apply to multiple nodes. The preferable restriction that there should be only one transmitting SD/SC means that a SD/SC should not transmit data in response to a group request; these requests are therefore only used for write operations, for example, for initial configuration of a group of devices.
[0092] Referring now to FIG. 5 a , this conceptually illustrates merging of data packets received at a sub-controller from a plurality of switching device controllers. State data from the switching device controllers is represented by a set of RT (real-time) flags, in embodiments 6 flags as previously described. This is ORed 500 together to merge the data from, potentially, up to of order 10 4 devices. This is because a transition (SIP) bit is provided which, during a transition, is active. Thus ORing the state data from the switching device controllers together indicates when all of the devices have reached the subsequent state because only then will none of the devices have the SIP bit set. In this way a state change complete 502 determination may be made. In an embodiment employing serial data communications at a bit rate of, say, approximately 1 Gbit/s each real-time packet takes approximately 24 ns to arrive and thus the state change complete determination may be made very quickly. The skilled person will appreciate, however, that parallel or partially parallel rather than serial communications may alternatively be employed using the same approach.
[0093] In embodiments the data from the switching device controllers also includes fault data in which one or more bits is active (either high or low) to indicate a fault. Again this fault data may then be ORed 500 together to identify for the set of switching device controllers whether or not a fault is present 504 . The resulting state change complete, and optional fault data may then be forwarded to the central controller, in embodiments after being assembled into one or more data packets.
[0094] In embodiments the data received from the switching device controllers also includes error detection data, in embodiments parity data for a hamming code. Then the procedure includes an error decoding process 506 to decode the hamming code, which may then be tested in order to detect an error in an acknowledgement data packet from any of the switching device controllers in the relevant branch of the tree. An error flag may then be set accordingly in the packet to the central controller. The skilled person will appreciate that there are alternative approaches which may be employed for handling the error detection data, in particular because merging this data potentially hides which switching device controller acknowledgement packet contained an error (although, preferably, the pre-merged data may be locally stored for interrogation to identify this). In some preferred embodiments error detection data is also included in the data forwarded from a sub-controller to the central controller; in embodiments this provides a facility to detect a two bit error and correct a one bit error (on the sub-controller to controller link).
[0095] FIG. 5 a also illustrates, conceptually, that where the parity bits are included within the state or other data sent from a switching device controller then the incoming data may be error checked as it arrives, reducing the error decode latency. This is because by the time the final portion of the incoming (serial) data has arrived some of the error decoding has already been carried out and therefore there may only be a small additional delay to determine whether the complete packet is either good (valid) or invalid, in the latter case a one bit error flag, E, being appended to the data out of the error decode process 506 , prior to ORing. In embodiments there may be an error decode latency of 1-5 bits, which at one bit per nanosecond is generally small compared with the propagation delay of signals within the control system. Most importantly, because since each bit is forwarded before the whole packet has been verified, a mechanism is needed to flag when a packet, after it has mostly sent out is in error. This is provided by an appended error flag which is covered by the last three bits of the Hamming code.
[0096] In embodiments the acknowledgement data received by a sub-controller from a switching device controller comprises a 24 bit frame. A sub-controller may receive, for example, 30 such frames, which are merged by ORing the data bits to determine the sub-system status. In embodiments one communications channel is provided for each switching device controller; this may be implemented as one or more ‘wires’ or fibre optic cables. As previously mentioned, a real time acknowledgement data packet comprises, inter alia, six flags. In the other direction, a switch state or other command sent to a switching device controller (node or SD) includes a group address, in embodiments comprising 5 bits. Such command packets are broadcast from the central controller and forwarded by the one or more sub-controllers to the switching device controllers, which interpret the command and, for example, change state accordingly. Alternatively, however, a parallel bus arrangement may be employed without the need for data packets or in embodiments such addressing techniques.
[0097] We will now describe in more detail an example preferred implementation of the data link layer
Data Link Layer
[0098] Broadly speaking, the data link layer provides an unreliable broadcast datagram service from CC to SDs and an unreliable unicast datagram service from SDs to CC (SDs cannot communicate directly between themselves, all communication is controlled by the master). The general format of the data frame from a controller to a node (CC->N), and vice versa (N->CC) is as follows:
[0000] Packet Direction type 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CC−>N T D9 D8 D7 D6 D5 D4 P4 D3 D2 D1 P3 D0 P2 P1 P0 N−>CC F5 F4 F3 F2 F1 F0 D9 P5 D8 D7 D6 D5 D4 D3 D2 P4 D1 D0 ME P3 E P2 P1 P0
where the following abbreviations are employed:
[0099] T Packet type
[0100] P[5:0] Parity
[0101] F[5:0] RT Flags
[0102] D[9:0] Data
[0103] E Error
[0104] ME Merge Error
[0105] In the outbound packet (CC->SD), the data may be RT or NRT data based on the T (type) flag. In the inbound packet (SD->CC), both RT and NRT data are present. The RT data comprises a set of flags used to transmit critical information from the SDs to the CC. The Parity bits P[5:0] and P[4:0] are a SECDED (“single error correction, double error detection”) Hamming code. The error bit, E, is set if a node received a bad packet. This can be a SD receiving a corrupted packet from the CC, or a SC receiving a corrupted packet from a SD. The error bit is sent late in the upstream packet so the SC can report a fault if the incoming upstream packet is in error (this requires a delay of a few bits in the SC since the E bit cannot be transmitted until the last parity bit has been received and checked). The merge error bit, ME, is set if sub-controller received non-null NRT data from two or more downstream devices. (This should only occur if there are two devices with identical addresses.)
[0106] The protocol has a request—response pattern: for every sent packet by the CC there is a received packet from the SDs. The CC is responsible for ensuring that RT traffic is prioritised over NRT traffic.
[0107] All the packets from the CC are forwarded by the SCs to all the SDs. When the packet is received by an SDs, the Hamming code is checked.
If a single bit error is detected, the error is corrected and the content of the frame is forwarded to the related upper layer based on the T flag. A single bit error counter is incremented for statistical purpose. If a double bit error is detected, the content of the frame is dropped and the E (error) flag is set in the reply packet. In every case (if the frame is corrupted or not), an outbound packet is sent back to the CC. If the CC receives a frame with the E flag set, then the previous frame is retransmitted until the reply frame has the E flag cleared or a retry counter expires.
[0111] If the reply frame received by the CC is corrupted and it can't be corrected (2 bits error), the content of the received packet can't be trusted and the CC sends the packet again.
[0112] Optionally frames may be dropped if a single-bit error is detected (a case in which it is possible to correct the error) as this reduces the probably of accepting an erroneous frame.
[0113] Each frame has a SECDED (“single error correction, double error detection”) Hamming code. For the outbound communication, each SDs has the capability to detect and correct single bit error. This is used to avoid retransmission on single bit error, since due to the huge number of SDs and to the high speed communication this type of error is likely to occur.
[0114] Sub-controllers send the downstream data CC->SD out to all output ports with minimal delay (i.e., without waiting for an entire packet to be received). As packets are going upstream from the SD to the CC, as previously described, every SC makes the OR function of: F[5:0], D[8:0] and E. The SC transmits the correct parity bits (P[5:0]) for the outgoing data (the parity bits are not OR'd together).
[0115] We now consider RT layer data packets. These have the format below:
[0000] Packet Direction type 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CC−>N RT RT G4 G3 G2 G1 G0 S3 S2 S1 S0 state CC−>N RT RT G4 G3 G2 G1 G0 A3 A2 A1 A0 comma nd N−>CC OC OV XX CE AIP SIP
where the following abbreviations are employed:
[0116] G[4:0] Group address
[0117] S[3:0] Switch status
[0118] A[3:0] Action
[0119] RT Packet type
[0120] (for RT Packet Type, 0=RT state i.e, the switch state sent to the node (SD) from the
[0121] CC; 1=RT action)
[0122] OC over-current
[0123] OV over-voltage
[0124] XX spare
[0125] CE Communications Error
[0126] AIP Action In Progress
[0127] SIP Switch status change In Progress
[0128] The group address is used to send RT data to different groups of SDs, for example different levels of a multilevel inverter. Group 0 is the broadcast group. Devices only act on RT requests where they are members of the RT addressing group. A group address is sent to the SD using NRT data packets and is made active using a RT action command packet. The switch status is a 4-bit number representing the desired switch state for the SD group.
[0129] The action command is a 4-bit number; example actions are: Reset device to power-on-status; Reset the NRT communications system; Apply the configuration stored in the device “shadow registers”. Bits from 23 to 18 are a set of flags used to transmit time critical information from the SDs to the CC.
[0130] The AIP and SIP flags are set when a SD receives a RT action command or switch status change. When the action or the switch status change is completed, the flag is reset. Due to the flags OR-ing of the SCs, the CC knows if at least one SD has not yet completed the action/change.
[0131] The RT data packet contains a set of fault flags (OC, OV and so forth) reporting the state of the set of SDs. Example faults which may be reported include over-current (desaturation), over-voltage, failure to establish an ON (or OFF) state (which may indicate a faulty gate drive), over-temperature, and a state in which the switching device controller is continually in a voltage-clamping state (which may indicate a fault elsewhere in the control system).
[0132] If an SD has a fault, for instance an over-voltage fault, a bit is set in the RT data and this is transmitted up to the SC. The SC performs an OR operation and sends this onwards. When the data arrives at the CC the information available is that there is a fault somewhere in the network, and the NRT data channel is then used to determine exactly where this fault is, for example by interrogating individual devices.
[0133] Each SD has a register that may be read to check its fault status. However in embodiments the latest fault status from every downstream port is cached by SCs and the location of a fault can then be determined by walking down the SC tree guided by the fault-status registers. On detection of a fault, part or all of the system can, if desired, be returned to a previous known good state by controlling the nodes to step back through the transitions and states which were taken to the faulty state (or alternatively move forward to a subsequent “safe” state).
[0134] We next consider the NRT transport layer, in which data packets have the following format:
[0000] Packet Direction type 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CC−>N NRT NT S D7 D6 D5 D4 D3 D2 D1 D0 data CC−>N NRT NT S C7 C6 C5 C4 C3 C2 C1 C0 control N−>CC NRT NT POR D7 D6 D5 D4 D3 D2 D1 D0 data N−>CC NRT NT POR C7 C6 C5 C4 C3 C2 C1 C0 control
where the following abbreviations are employed:
[0135] D[7:0] Data
[0136] C[7:0] Control
[0137] NT Packet type
[0138] S Sequence flag
[0139] POR Power-On/Reset
[0140] The NRT packet contains either an 8-bit data byte or an 8-bit control code. The Power-On/Reset bit, POR, is set if a device has been powered on or reset and remains set until the device has an address assigned to it. (This enables the CC to detect when a device is attached to the system during operation.) The control bits signify, inter alia, the start and end of packet (which is composed of a variable number of NRT data frames payload and which may have up to, say, 64 bytes).
[0141] The sequence flag is used to provide a reliable broadcast datagram service. When a NRT frame is received, the S flag of the frame is compared with the internal sequence flag within the receiving node. If the two flags are not equal, then the data coming from the outbound frame is ignored otherwise the new data is inserted in the inbound frame and the internal sequence flag negated.
[0142] The NRT communication protocol makes the use of 20-bit device addresses. There are three classes of address:
[0143] 1. A “device addresses” take the form a.b.c.d where the first component is 1.30, and all other components are 0.30. This address defines an individual device.
[0144] 2. A “wildcard address” is as a device addresses, but one or more of the components take the value 31 which means “any device”. For example 1.2.31.0 refers to all devices 1.2.x.0 where x is 0.30.
[0145] 3. A “group address” takes the form 0.x.y.z where the 15-bit number xyz identifies a group of devices.
[0146] All slave devices (i.e., not the central controller) have a single device identifier. The central controller is responsible for assigning address devices based on their location in the network. Referring to FIG. 5 b , this shows a small network attached to a single central-controller output port (port 1) to demonstrate the addressing scheme. Circles represent sub-controller nodes, rectangles represent individual devices. At each layer in the diagram a digit is added to the address.
[0147] Wildcard addresses enable addressing a group of nodes based on their location in the tree. The wildcard part of the address is indicated with the value 31 (which is an invalid port number). For example:
[0148] 1.31.0.0.0 will address all devices connected directly to the central controller.
[0149] 2.31.31.0.0 will address all devices in the first and second levels of the tree.
[0150] 3.1.2.3.31 addresses all devices connected to the sub-controller with address 1.2.3.0.
[0151] 4.31.31.31.31 addresses all devices on the network.
[0152] Group addresses allow for the addressing of devices based on dynamically managed groups. These groups may be managed by the central controller setting the group address registers within devices, or may be based on a property of the device (for example, whether a NRT address has been assigned to the device). The following groups are predefined:
[0000]
Name
Address
Purpose
GROUP_ALL
0.0.0.0
Broadcast to all devices
(same as 31.31.31.31)
GROUP_HAS_ADDRESS
0.0.0.1
Broadcast to all devices that
have a value NRT device address.
GROUP_NO_ADDRESS
0.0.0.2
Broadcast to all devices that have not
yet been assigned an NRT address.
This is used during the enumeration
protocol.
[0153] A device enumeration scheme is used when assigning addresses to devices. Before an address has been assigned to a device it cannot be individually addressed, it can only be accessed using a broadcast/group address. Therefore an algorithm is used that ensures that if a group address is used to set a device address, that the group contains that device and no other. This is done by manipulating the set of enabled NRT output ports on sub-controllers. The algorithm executes on each CC output port, N, and assigns addresses N.a.b.c to the nodes. The algorithm begins with the following steps:
[0154] 1. Send Reset action to the broadcast RT group (thus all nodes have addresses cleared, and all SC outputs are closed to NRT traffic).
[0155] 2. Assign address N using the group address GROUP_NO_ADDRESS (this node is either a SD, or a SC with all outputs disabled, thus only one device responds).
[0156] 3. Perform the “enumeration algorithm” below starting with address N.
[0157] The enumeration algorithm is recursive on the devices, beginning with address N. The procedure reads the device type and if the device is not a SC the algorithm ends. Otherwise, if the device is a sub-controller: disable all output-ports on the SC, then for each output port, i:
[0158] 1. Enable output port i.
[0159] 2. Assign address to the device i using the group address GROUP_NO_ADDRESS.
[0160] 3. Run the enumeration algorithm on device i (a depth-first-search down the tree).
[0161] 4. Disable output port i.
[0162] Then enable all output ports.
[0163] Referring now to FIG. 5 c , this shows a block diagram of a sub-controller 550 arranged to implement the techniques described above, according to an embodiment of the invention. Thus the sub-controller comprises a set of ports 552 a - c each of which (apart from port 0, which is local) comprises data transceivers 554 , an encoder 556 for transmitted data, a decoder and data recovery function 558 for received data and, a FIFO 560 and, preferably, a parity decoder 562 . The outputs from the decoded received data and from the parity decoder for each port are provided to a port ORing block 500 , broadly as previously described, which is then followed by parity and data encoder functions 570 , 572 , for onward re-transmission to the central controller. A physical interface comprises a pair of data transceivers 574 , and the received data is provided to a decoder and data recovery function 576 which provides a clock signal to block 500 , and also an input to this block via local port 0. In control systems with more than one sub-controller layer port 574 may communicate with another sub-controller. Thus in embodiments there are 32 bi-directional ports, one ‘inbound’, 30 ‘outbound’ and one internal. Since, in embodiments each port is half-duplex, in embodiments a pair of buffers is provided for each external port controlled by the sub-controller logic.
[0164] In embodiments, in operation one or both of encoders 556 , 572 encode a digital I/O level bit stream using a ternary code, for example, the hybrid (H-) ternary code, into 3 levels, positive, zero, and negative. The decoding and data recovery box 558 , 576 decode these 3 levels to a two level digital bit stream, and also align the data to an internal clock. FIFO 560 stores incoming data up to a complete frame. The parity decoder 562 checks the Hamming code of the incoming frame. In embodiments port 0 includes a local node module 578 , which is an internal node looking similar to other nodes to an SD, used to configure the sub-controller itself.
[0165] Inbound data (from the central controller) is sent substantially without modification to all the outbound ports (towards the nodes/SDs) and towards the local port. In doing this the inbound data stream is de-coded to allow the internal sub-controller logic to identify the start of a frame and to drive the buffers accordingly; for the external outbound ports the data stream is then re-encoded before forwarding.
[0166] Data arriving from one of the nodes/SDs (and also the internal port) is merged on a bit-by-bit basis. Preferably each incoming data stream from a node/SD (optionally via another sub-controller) is temporarily stored in a FIFO. This is so that there is no need for length matching among cables from the sub-controller to their destination (other sub-controllers or nodes), allowing the incoming data bits to arrive at different times. When the first bit of a frame is stored by the FIFO for all ports, the sub-controller logic starts to read data from the FIFOs, ORing the data stream bit by bit. All the bits are ORed, except for parity bits. In the case of an NRT data packet only one port receives data and the other ports receive a null packet comprising all Os, so that ORing does not modify the data. If more than one port receives an NRT data packet a merge error is flagged, allowing the central controller to take corrective action. Each bit is then forwarded to the inbound port after a 4 bit delay (see below).
[0167] Preferably the merged data stream is forwarded as soon as possible and before the complete frame is stored (and therefore a parity mechanism such as a Cyclic Redundancy Check, with the parity stream at the end of the frame, is not used). In embodiments, the parity bit string is not stored at the end of the frame but it is spread over the frame, and when the tail of a frame is received by the SC, most of the merged frame has already been forwarded towards the CC. A Hamming code parity scheme is used since this is a distributed parity mechanism and when a parity bit (P) is received that bit covers (only) the frame data bits (D) received so far, as shown below:
[0000]
D
D
D
D
D
D
D
P0
D
D
D
D
D
D
D
P1
D
D
D
P2
D
P3
P4
P5
[0168] Each parity bit can be checked as soon as it arrives and there is no need to wait for the complete frame. This raises the possibility of invalidating the forwarded frame when sending the last data bit (bit 3 , Error flag), while it is still covered by the parity scheme. To achieve this, each bit is then forwarded to the inbound port after a 4 bit delay (and so the frame is forwarded with a 4 bits delay). At the end of the frame, the SC receives the last 3 parity bits (P2 to P0) and checks them. Then the SC sets the Error flag if the packet is corrupted (one or two bit error) and calculates a new value for P2-P0 before forwarding the last four bits of the frame.
[0169] This protocol provides different error checking/correcting capabilities for the outbound (from the SC) and inbound (into the SC) data flows: In embodiments, for an outbound data flow each SD or SC local node can correct single bit errors and detect double bits errors. For an inbound data flow a single or double bit error can be detected by each SC, but no correction is possible. Thus in embodiments a single bit error can be corrected by the CC only if the frame is corrupted between the CC and a SC connected directly to the CC (as opposed to one connected via another SC).
[0170] It is desirable to be able to update the configuration of a switching device controller at a defined time, for example when a switching action is not taking place. However the configuration data may be too large to send in a real-time packet and thus, in embodiments, the configuration information is updated in a two stage process making use of a ‘shadow configuration’ within each switching device controller (SD).
[0171] Referring now to FIG. 6 a , this shows details of the digital logic 140 of FIG. 1 . As previously mentioned, a switch state is requested by a real-time message from the central controller (and similarly acknowledged when achieved), whilst configuration and monitoring data can be sent and received by non-real-time messages. Thus the interface to bus 122 comprises real-time logic 150 and non real-time logic 152 . In embodiments the controller includes two register banks 154 a,b storing configuration data which is selectable by multiplexor 156 . The register banks are programmed by the digital logic, which also controls which register bank is active, and which one can be written to. The register bank that is active provides parameter information that configures the switching device controller. The register bank that is not active can be updated via the communications interface, and then made active so that this new parameter data controls the system state. This enables real-time update of the controller configuration, and synchronised update in a system with many switches/controllers.
[0172] Thus in operation one of the register banks functions to store shadow configuration data, and the other to store active configuration data. The shadow configuration is updated for the nodes for which a configuration change is desired, using NRT frames. Changes to the shadow configuration, however, have no effect on the switching behaviour of the device. Then the shadow configuration is copied to the active configuration register bank (or the designation of which is the shadow and which is the active register bank is switched), using a real-time action command. The error bit in the data link layer allows the central controller to detect where one or more devices did not receive this action command, so that the command can be re-transmitted. In one embodiment a register bank comprises 4K 32-bit words of addressable memory.
[0173] FIG. 6 b illustrates an example procedure for writing data from the central controller into registers within (the address may be an individual device address or a device group address). As can be seen, an NRT message provides the device address and the payload of this message, the register address and register contents; and a further NRT message is used for acknowledgement of status data (valid or error). Similarly FIG. 6 c illustrates a read request in which the central controller reads the contents of one or more registers within an individual addressed device. The payload of an NRT message carries the register address and the register contents are provided back in the payload of a further NRT message. The returned data may be, for example, configuration and/or measurement data.
[0174] No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.
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We describe a system for controlling very large numbers of power semiconductor switching devices ( 132 ) to switch in synchronisation. The devices are high power devices, for example carrying hundreds of amps and/or voltages of the order of kilovolts. In outline the system comprises a coordinating control system ( 110, 120 ), which communicates with a plurality of switching device controllers ( 130 ) to control the devices into a plurality of states including a fully-off state, a saturated-on state, and at least one intermediate state between the fully-off and saturated-on states, synchronising the devices in the at least one intermediate state during switching.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/901,838, filed Jul. 10, 2001, now U.S. Pat. No. 6,493,934. issued Dec. 17, 2002, which is a divisional of application Ser. No. 09/567,643, filed May 9, 2000, now U.S. Pat. No. 6,401,580, issued Jun. 11, 2002, which is a divisional of application Ser. No. 09/434,147, filed Nov. 4, 1999, now U.S. Pat. No. 6,196,096, issued Mar. 6, 2001, which is a continuation of application Ser. No. 09/270,539, filed Mar. 17, 1999, now U.S. Pat. No. 6,155,247, issued Dec. 5, 2000, which is a divisional of application Ser. No. 09/069,561, filed Apr. 29, 1998, now U.S. Pat. No. 6,119,675, issued Sep. 19, 2000, which is a divisional of application Ser. No. 08/747,299, filed Nov. 12, 1996, now U.S. Pat. No. 6,250,192, issued Jun. 26, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a method and apparatus for sawing semiconductor substrates such as wafers and, more specifically, to a wafer saw and a method of using the same employing multiple indexing techniques and multiple blades for more efficient sawing and for sawing multiple die sizes and shapes from a single semiconductor wafer.
2. State of the Art
An individual integrated circuit or chip is usually formed from a larger structure known as a semiconductor wafer, which is usually comprised primarily of silicon, although other materials such as gallium arsenide and indium phosphide are also sometimes used. Each semiconductor wafer has a plurality of integrated circuits arranged in rows and columns with the periphery of each integrated circuit being rectangular. Typically, the wafer is sawn or “diced” into rectangularly shaped discrete integrated circuits along two mutually perpendicular sets of parallel lines or streets lying between each of the rows and columns thereof. Hence, the separated or singulated integrated circuits are commonly referred to as dice.
One exemplary wafer saw includes a rotating dicing blade mounted to an aluminum hub and attached to a rotating spindle, the spindle being connected to a motor. Cutting action of the blade may be effected by diamond particles bonded thereto, or a traditional “toothed” type blade may be employed. Many rotating wafer saw blade structures are known in the art. The present invention is applicable to any saw blade construction, so further structures will not be described herein.
Because semiconductor wafers in the art usually contain a plurality of substantially identical integrated circuits arranged in rows and columns, two sets of mutually parallel streets extending perpendicular to each other over substantially the entire surface of the wafer are formed between each discrete integrated circuit and are sized to allow passage of a wafer saw blade between adjacent integrated circuits without affecting any of their internal circuitry. A typical wafer sawing operation includes attaching the semiconductor wafer to a wafer saw carrier, mechanically, adhesively or otherwise, as known in the art, and mounting the wafer saw carrier on the table of the wafer saw. A blade of the wafer saw is passed through the surface of the semiconductor wafer by moving either the blade relative to the wafer or the table of the saw and the wafer relative to a stationary blade, or a combination of both. To dice the wafer, the blade cuts precisely along each street, returning back over (but not in contact with) the wafer while the wafer is laterally indexed to the next cutting location. Once all cuts associated with mutually parallel streets having one orientation are complete, either the blade is rotated 90° relative to the wafer or the wafer is rotated 90°, and cuts are made through streets in a direction perpendicular to the initial direction of cut. Since each integrated circuit on a conventional wafer has the same size and rectangular configuration, each pass of the wafer saw blade is incrementally indexed one unit (a unit being equal to the distance from one street to the next) in a particular orientation of the wafer. As such, the wafer saw and the software controlling it are designed to provide uniform and precise indexing in fixed increments across the surface of a wafer.
It may, however, be desirable to design and fabricate a semiconductor wafer having various integrated circuits and other semiconductor devices thereon, each of which may be of a different size. For example, in radio-frequency ID (RFID) applications, a battery, chip and antenna could be incorporated into the same wafer such that all semiconductor devices of an RFID electronic device are fabricated from a single semiconductor wafer. Alternatively, memory dice of different capacities, for example, 4, 16 and 64 megabyte DRAMs, might be fabricated on a single wafer to maximize the use of silicon “real estate” and reduce thiefage or waste of material near the periphery of the almost-circular (but for the flat) wafer. Such semiconductor wafers, in order to be diced, however, would require modifications to and/or replacement of existing wafer saw hardware and software.
SUMMARY OF THE INVENTION
Accordingly, an apparatus and method for sawing semiconductor wafers, including wafers having a plurality of semiconductor devices of different sizes and/or shapes therein are provided. In particular, the present invention provides a wafer saw and method of using the same, capable of “multiple indexing” of a wafer saw blade or blades to provide the desired cutting capabilities. As used herein, the term “multiple indexing” contemplates and encompasses both the lateral indexing of a saw blade at multiples of a fixed interval and at varying intervals which may not comprise exact multiples of one another. Thus, for conventional wafer configurations containing a number of equally sized integrated circuits, the wafer saw and method herein can substantially simultaneously saw the wafers with multiple blades and, therefore, cut more quickly than single blade wafer saws known in the art. Moreover, for wafers having a plurality of differently sized or shaped integrated circuits, the apparatus and method herein provide a multiple indexing capability to cut nonuniform dice from the same wafer.
In a preferred embodiment, a single-blade, multi-indexing saw is provided for cutting a wafer containing variously configured integrated circuits. By providing multiple-indexing capabilities, the wafer saw can sever the wafer into differently sized dice corresponding to the configuration of the integrated circuits contained thereon.
In another preferred embodiment, a wafer saw is provided having at least two wafer saw blades spaced a lateral distance from one another and having their centers of rotation in substantial parallel mutual alignment. The blades are preferably spaced apart a distance equal to the distance between adjacent streets on the wafer in question. With such a saw configuration, multiple parallel cuts through the wafer can be made substantially simultaneously, thus essentially increasing the speed of cutting a wafer by the number of blades utilized in tandem. Because of the small size of the individual integrated circuits and the correspondingly small distances between adjacent streets on the wafer, it may be desirable to space the blades of the wafer saw more than one street apart. For example, if the blades of a two-blade saw are spaced two streets apart, a first pass of the blades would cut the first and third laterally separated streets. A second pass of the blades through the wafer would cut through the second and fourth streets. The blades would then be indexed to cut through the fifth and seventh streets, then sixth and eighth, and so on.
In another preferred embodiment, at least one blade of a multi-blade saw is independently raisable relative to the other blade or blades when only a single cut is desired on a particular pass of the carriage. Such a saw configuration has special utility where the blades are spaced close enough to cut in parallel on either side of larger integrated circuits, but use single blade capability for dicing any smaller integrated circuits. For example, a first pass of the blades of a two-blade saw could cut a first set of adjacent streets defining a column of larger integrated circuits of the wafer. One blade could then be independently raised or elevated to effect a subsequent pass of the remaining blade cutting along a street that may be too laterally close to an adjacent street to allow both blades to cut simultaneously, or that merely defines a single column of narrower dice. This feature would also permit parallel scribing of the surface of the wafer to mutually isolate conductors from, for example, tie bars or other common links required during fabrication, with subsequent passage by a single blade indexed to track between the scribe lines to completely sever or singulate the adjacent portions of the wafer.
In yet another preferred embodiment, at least one blade of a multi-blade saw is independently laterally translatable relative to the other blade or blades. Thus, in a two-blade saw, for example, the blades could be laterally adjusted between consecutive saw passes of the sawing operation to accommodate different widths between streets. It should be noted that this preferred embodiment could be combined with other embodiments herein to provide a wafer saw that has blades that are both laterally translatable and independently raisable, or one translatable and one raisable, as desired.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic side view of a first preferred embodiment of a wafer saw in accordance with the present invention;
FIG. 2 is a schematic front view of the wafer saw illustrated in FIG. 1;
FIG. 3 is a schematic front view of a second embodiment of a wafer saw in accordance with the present invention;
FIG. 4 is a schematic view of a first prior art silicon semiconductor wafer having a conventional configuration to be diced with the wafer saw of the present invention;
FIG. 5 is a schematic view of a second silicon semiconductor wafer having variously sized semiconductor devices therein to be diced with the wafer saw of the present invention;
FIG. 6 is a schematic front view of a third embodiment of a wafer saw in accordance with the present invention;
FIG. 7 is a schematic view of a third silicon semiconductor wafer having variously sized semiconductor devices therein to be diced with the wafer saw of the present invention;
FIG. 8 is a top elevation of a portion of a semiconductor substrate bearing conductive traces connected by tie bars; and
FIG. 9 is a top elevation of a portion of a semiconductor substrate bearing three different types of components formed thereon.
DETAILED DESCRIPTION OF THE INVENTION
As illustrated in FIGS. 1 and 2, an exemplary wafer saw 10 according to the invention is comprised of a base 12 to which extension arms 14 and 15 suspended by support 16 are attached. A wafer saw blade 18 is attached to a spindle or hub 20 which is rotatably attached to the extension arm 15 . The wafer saw blade 18 may be secured to the hub 20 and extension arm 15 by a threaded nut 21 or other means of attachment known in the art. The wafer saw 10 also includes a translatable wafer table 22 movably attached in both X and Y directions (as indicated by arrows in FIGS. 1 and 2) to the base 12 . Alternatively, wafer saw blade 18 may be translatable relative to the wafer table 22 to achieve the same relative X-Y movement of the wafer saw blade 18 to the wafer table 22 . A silicon wafer 24 to be scribed or sawed may be securely mounted to the wafer table 22 . As used herein, the term “saw” includes scribing of a wafer, the resulting scribe line 26 not completely extending through the wafer substrate. Further, the term “wafer” includes traditional full semiconductor wafers of silicon, gallium arsenide, or indium phosphide and other semiconductor materials, partial wafers, and equivalent structures known in the art wherein a semiconductor material table or substrate is present. For example, so-called silicon-on-insulator, or “SOI,” structures, wherein silicon is carried on a glass, ceramic or sapphire (“SOS”) base, or other such structures as known in the art, are encompassed by the term “wafer” as used herein. Likewise, “semiconductor substrate” may be used to identify wafers and other structures to be singulated into smaller elements.
The wafer saw 10 is capable of lateral multi-indexing of the wafer table 22 or wafer saw blade 18 or, in other words, translatable, from side-to-side in FIG. 2 and into and out of the plane of the page in FIG. 1, various nonuniform distances. As noted before, such nonuniform distances may be mere multiples of a unit distance, or may comprise unrelated varying distances, as desired. Accordingly, a wafer 24 having variously sized integrated circuits or other devices or components therein may be sectioned or diced into its nonuniformly sized components by the multi-indexing wafer saw 10 . In addition, as previously alluded, the wafer saw 10 may be used to create scribe lines or cuts 26 that do not extend through the wafer 24 . The wafer 24 can then subsequently be diced by other methods known in the art or sawed completely through after the wafer blade 18 has been lowered to traverse the wafer to its full depth or thickness.
Before proceeding further, it will be understood and appreciated that design and fabrication of a wafer saw according to the invention having the previously referenced, multi-indexing capabilities, independent lateral blade translation and independent blade raising or elevation are within the ability of one of ordinary skill in the art and that, likewise, the control of such a device to effect the multiple-indexing (whether in units of fixed increments or otherwise), lateral blade translation and blade elevation may be effected by suitable programming of the software-controlled operating system, as known in the art. Accordingly, no further description of hardware components or of a control system to effectuate operation of the apparatus of the invention is necessary.
Referring now to FIG. 3, another illustrated embodiment of a wafer saw 30 is shown having two laterally spaced blades 32 and 34 with their centers of rotation in substantial parallel alignment transverse to the planes of the blades. For a conventional, substantially circular silicon semiconductor wafer 40 (flat omitted), as illustrated in FIG. 4, having a plurality of similarly configured integrated circuits 42 arranged in evenly spaced rows and columns, the blades can be spaced a distance D substantially equal to the distance between adjacent streets 44 defining the space between each integrated circuit 42 . In addition, if the streets 44 of wafer 40 are too closely spaced for side-by-side blades 32 and 34 to cut along adjacent streets, the blades 32 and 34 can be spaced a distance D substantially equal to the distance between two or more streets. For example, a first pass of the blades 32 and 34 could cut along streets 44 a and 44 c and a second pass along streets 44 b and 44 d . The blades could then be indexed to cut the next series of streets and the process repeated for streets 44 e , 44 f , 44 g , and 44 h . If, however, the integrated circuits of a wafer 52 have various sizes, such as integrated circuits 50 and 51 as illustrated in FIG. 5, at least one blade 34 is laterally translatable relative to the other blade 32 to cut along the streets, such as street 56 , separating the variously sized integrated circuits 50 , 51 . The blade 34 may be variously translatable by a stepper motor 36 having a lead screw 38 (FIG. 3) or by other devices known in the art, such as high precision gearing in combination with an electric motor or hydraulics or other suitable mechanical drive and control assemblies. For a wafer 52 , the integrated circuits, such as integrated circuits 50 and 51 , may be diced by setting the blades 32 and 34 to simultaneously cut along streets 56 and 57 , indexing the blades, setting them to a wider lateral spread and cutting along streets 58 and 59 , indexing the blades while monitoring the same lateral spread or separation and cutting along streets 60 and 61 , and then narrowing the blade spacing and indexing the blades and cutting along streets 62 and 63 . The wafer 52 could then be rotated 90°, as illustrated by the arrow in FIG. 5, and the blade separation and indexing process repeated for streets 64 and 65 , streets 66 and 67 , and streets 68 and 69 .
As illustrated in FIG. 6, a wafer saw 70 according to the present invention is shown having two blades 72 and 74 , one of which is independently raisable (as indicated by an arrow) relative to the other. As used herein, the term “raisable” includes vertical translation either up or down. Such a configuration may be beneficial for situations where the distance between adjacent streets is less than the minimum lateral achievable distance between blades 72 and 74 , or only a single column of narrow dice is to be cut, such as at the edge of a wafer. Thus, when cutting a wafer 80 , as better illustrated in FIG. 7, the two blades 72 and 74 can make a first pass along streets 82 and 83 . One blade 72 can then be raised, the wafer 80 indexed relative to the unraised blade 74 and a second pass performed along street 84 only. Blade 72 can then be lowered and the wafer 80 indexed for cutting along streets 85 and 86 . The process can be repeated for streets 87 (single-blade pass), 88 , and 89 (double-blade pass). The elevation mechanism 76 for blade 72 may comprise a stepper motor, a precision-geared hydraulic or electric mechanism, a pivotable arm which is electrically, hydraulically or pneumatically powered, or other means well known in the art.
Finally, it may be desirable to combine the lateral translation feature of the embodiment of the wafer saw 30 illustrated in FIG. 3 with the independent blade raising feature of the wafer saw 70 of FIG. 6 . Such a wafer saw could use a single blade to cut along streets that are too closely spaced for dual-blade cutting or in other suitable situations, and use both blades to cut along variously spaced streets where the lateral distance between adjacent streets is sufficient for both blades to be engaged.
It will be appreciated by those skilled in the art that the embodiments herein described while illustrating certain embodiments are not intended to so limit the invention or the scope of the appended claims. More specifically, this invention, while being described with reference to semiconductor wafers containing integrated circuits or other semiconductor devices, has equal utility to any type of substrate to be scribed or singulated. For example, fabrication of test inserts or chip carriers formed from a silicon (or other semiconductor) wafer and used to make temporary or permanent chip-to-wafer, chip-to-chip and chip-to-carrier interconnections and that are cut into individual or groups of inserts, as described in U.S. Pat. Nos. 5,326,428 and 4,937,653, may benefit from the multi-indexing method and apparatus described herein.
For example, illustrated in FIG. 8, a semiconductor substrate 100 may have traces 102 formed thereon by electrodeposition techniques that require connection of a plurality of traces 102 through a tie bar 104 . A two-blade saw in accordance with the present invention may be employed to simultaneously scribe substrate 100 along parallel lines 106 and 108 flanking a street 110 in order to sever tie bars 104 of adjacent substrate segments 112 from their associated traces 102 . Following such severance, the two columns of adjacent substrate segments 112 (corresponding to what would be termed “dice” if integrated circuits were formed thereon) are completely severed along street 110 after the two-blade saw is indexed for alignment of one blade therewith, and the other blade raised out of contact with substrate 100 . Subsequently, when either the saw or the substrate carrier is rotated 90°, singulation of the segments 112 is completed along mutually parallel streets 114 . Thus, substrate segments 112 for test or packaging purposes may be fabricated more efficiently in the same manner as dice and in the same sizes and shapes.
Further, and as previously noted, RFID modules may be more easily fabricated when all components of a module are formed on a single wafer and retrieved therefrom for placement on a carrier substrate providing mechanical support and electrical interconnection between components.
As shown in FIG. 9, a portion of a substrate 200 is depicted with three adjacent columns of varying-width segments, the three widths of segments illustrating batteries 202 , chips 204 and antennas 206 of an RFID device. With all of the RFID components formed on a single substrate 200 , an RFID module may be assembled by a single pick-and-place apparatus at a single work station. Thus, complete modules may be assembled without transfer of partially assembled modules from one station to the next to add components. Of course, this approach may be employed to any module assembly wherein all of the components are capable of being fabricated on a single semiconductor substrate. Fabrication of different components by semiconductor device fabrication techniques known in the art is within the ability of those of ordinary skill in the art, and, therefore, no detailed explanation of the fabrication process leading to the presence of different components on a common wafer or other substrate is necessary. Masking of semiconductor device elements not involved in a particular process step is widely practiced and so similar isolation of entire components is also easily effected to protect the elements of a component until the next process step with which it is involved.
Further, the present invention has particular applicability to the fabrication of custom or nonstandard ICs or other components, wherein a capability for rapid and easy die size and shape adjustment on a wafer-by-wafer basis is highly beneficial and cost-effective. Those skilled in the art will also understand that various combinations of the preferred embodiments could be made without departing from the spirit of the invention. For example, it may be desirable to have at least one blade of the independently laterally translatable blade configuration be independently raisable relative to the other blade or blades, or a single blade may be both translatable and raisable relative to one or more other blades and to the target wafer. In addition, while for purposes of simplicity some of the preferred embodiments of the wafer saw are illustrated as having two blades, those skilled in the art will appreciate that the scope of the invention and appended claims is intended to cover wafer saws having more or less than two blades. Thus, while certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes in the invention disclosed herein may be made without departing from the scope of the invention, which is defined in the appended claims.
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A semiconductor wafer saw and method of using the same for dicing semiconductor wafers comprising a wafer saw including variable lateral indexing capabilities and multiple blades are disclosed. The wafer saw, because of its variable indexing capabilities, can dice wafers having a plurality of differently sized semiconductor devices thereon into their respective discrete components. In addition, the wafer saw with its multiple blades, some of which may be independently laterally or vertically movable relative to other blades, can more efficiently dice silicon wafers into individual semiconductor devices. The wafer saw may also be used to simultaneously sever and electrically isolate conductive traces that extend over adjacent semiconductor devices from connective lines therefor.
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